Hydraulic Press & Machines

For several years STRECON has been developing and manufacturing compact hydraulic press machines for different purposes including tool assembly by press fitting, high-pressure experiments at universities and research centers, and series production of components and parts.

All hydraulic press units with press force from 150T are made with a special prestressed press frame based on the stripwinding technology. Specifically, a stripwound press frame remains fully elastic under maximum loaded conditions (i.e. the press frame remains in a compressive state of stress). Another advantage of the stripwound press frame is that tasks such as tool assembly need reduced press force due to a highly parallel piston movement to the press table. This feature also minimizes the risk of skew assembly of forging tools.

The stripwinding technology was originally developed by STRECON for the design and manufacturing of high-strength prestressing tool systems but was later applied to the design and manufacturing of compact, high-strength hydraulic press machines. Read more about the stripwinding technology and its unique features here.

A hydraulic press machine from STRECON is recognized to be very robust and high-quality equipment characterized by low weight, small footprint, easy to operate and maintain, and reliable in use.
 

The Concept of Hydraulic Power Solutions

Hydraulics is widely used in today’s industry and takes up many different forms and industrial applications. STRECON applies hydraulics to several machine and equipment solutions as it is a technically intelligent, robust, and cost-effective solution. See also our hydraulic equipment solution for horizontal alignment of large tool systems.

The main idea of hydraulics in press machines is to have high and consistent power for delivering a robust and stable movement of one or several press pistons.

Press units from 150T in press force are equipped with a 600bar hydraulic power system, whereas the smaller press units would normally be designed with a standard 300bar hydraulic power solution. The 600bar hydraulic power system allows for press units with physically “smaller” hydraulic cylinders, contributing to a compact mechanical equipment structure with reduced size, weight, and footprint.

For lowering the electrical consumption, and for optimizing the press operations, the hydraulic power pack is divided into two (2) pressure circuits, though still using the same electrical motor:

  • Low-pressure/high volume for idling speed of the piston, and
  • High-pressure/low volume for high-pressure piston movement under controlled loaded conditions.

The hydraulic power system is normally equipped with a proportional valve technique for smooth and fully controlled movement of the press cylinder, and it is operated by a joystick.
The hydraulic controls system is based on an industrial PLC with a user-friendly HMI touchscreen. This solution does also allow for remote technical support to the press machine in case of malfunctioning.

Alternatively, we can offer an analogue control system with a pneumatic pressure regulation by which the desired hydraulic pressure can be preset and adjusted. This is a unique design feature for controlling the hydraulic system of the press unit.

Tool Assembly Press Technology, TAP

The Tool Assembly Press (TAP) from STRECON is a hydraulic press machine designed specifically for high-quality assembly, disassembly, and die setting of high-loaded tools by press fitting.

The purpose of press fitting is to prestress a die or insert at a predefined level of compressive stress, which in practice is expressed as a nominal oversize of the die or insert. Press fitting of dies and inserts is widely used in industrial applications like cold and warm forging, deep drawing, bar drawing, and powder compaction but also at tools used for high-pressure experiments and synthesis of industrial diamonds. Press fitting is recognized as an effective tool assembly method, and it is valued to be fast, safe, and ecological compared to the assembly technique by heat shrinkage.

STRECON’s press technology can principally be compared to a hydraulic die assembler from Sack & Kiesselbach and Stenhøj. However, STRECON’s mechanical press construction is based on the compression of the press frame by stripwinding and the use of a 600bar hydraulic powerpack, and higher like 700bar if needed. This technical solution offers unique advantages such as compact design, lightweight, and strength.

For details on the tool assembly presses, please follow this link.

HPE Press Technology

The HPE Press is a hydraulic piston-cylinder apparatus for high-pressure and high-temperature testing at universities and laboratories.

Like TAP, the piston cylinder press frame is compressed by stripwinding for obtaining high strength as well as reducing both the volume and weight of the press. The stripwound press frame is a unique equipment feature developed by STRECON that ensures a powerful yet lightweight and compact apparatus.

In general, the HPE press from STRECON can be compared to other types of high-pressure apparatus like Griggs apparatus, Rockland piston-cylinder system, Voggenreiter high-pressure apparatus, Sanchez Technologies laboratory equipment, Boyd & England style piston-cylinder press, Bristol piston-cylinder press, and Pretech Triaxial Deformation testing machine. Specifically, the high-pressure apparatus from STRECON is equipped with the twin-cylinder technology also known from other manufacturers, but the hydraulic system solution from STRECON allows for individual and variable pressure adjustment of the end-load and the process load, respectively. This hydraulic power solution is a distinctive feature compared to other press manufacturers.

The high-pressure tooling for the HPE press, also known as high-pressure vessels, are also made by the stripwinding technique and offers vessels that are twice as strong as standard vessels from other manufacturers. This unique tooling feature allows for a higher core pressure and improved service life of the carbide die. In addition, the STRECON vessels can be reused numerous times at full capacity as they remain in a fully elastic state even at maximum process load.

The vessels can be offered with a cooling system and/or heating system assembled on each side. Read more about the tool solutions for HPE here.

University of Geneve:
A recent example of a HPE Press solution installed at the University of Geneve is a high-pressure / high-temperature testing equipment specifically made for simulating and measuring the mechanical properties of rocks under brittle-plastic transition conditions corresponding to the earthquake epicenter area. In addition to the R&D purpose itself, the HPE Press is designed for the following operational mode:

  • Maintain the same cell pressure for days or weeks, and controlled by a pneumatic/hydraulic system solution
  • No or low noise when maintaining process pressure
  • Economic advantage due to very low air consumption while maintaining hydraulic pressure
  • Compact press design, and a small footprint
  • No heating of the hydraulic oil

Read more about the HPE Press here.

Customized Press Solutions

STRECON is offering a series of press machines for tool assembly and R&D high-pressure testing at universities, which would fulfill the requirements of most customers, or at least with limited customization. However, STRECON does also welcome fully customized hydraulic press solutions if they by far can be designed and built on existing engineering capabilities and manufacturing capacity.

Tooling and handling equipment would normally take part in STRECON’s project delivery, and the equipment specification is crafted together with the individual customer. For example, a press equipment project could include the hydraulic press itself, high-pressure tooling, cooling and/or heating devices, part feeding, and -handling. Such an equipment development project would be subject to approval before dispatch (i.e. FAT) and at installation at the customer’s site (i.e. SAT and commissioning).

A development project may be initiated with a feasibility study in which principal technical topics are examined and validated before the “real” equipment project is launched.

Examples of technologies and/or equipment features that could come into consideration:

  • Stripwinding of press frame
  • Stripwinding of high-pressure tooling
  • 250 bar “normal” hydraulic power pack
  • 600 bar high-pressure hydraulic pack for compact press design
  • Servo spindle power pack, for very precise pressure and speed control
  • Induction heating
  • Handling tools for thermoplastic
  • Cooling of tools and parts
  • Part feeding and handling devices, for example by a robot
  • Safe enclosure of the press with interlock
  • User and service-friendly press design
  • Spare parts and service
  • Remote support

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