Special report in the professional magazine:
Der Schnitt- und Stanzwerkzeugbau (05/2003)

From the hydraulic press to the user-specific system

Röcher GmbH Maschinenbau, D-57250 Netphen-Deuz, is a manufacturer of hydraulic presses.

Whether it is about punching, drawing, stamping, bending, sizing, inserting, bordering, deburring, straightening or assembling, the complete range of the forming technique is covered. To accomplish this, the presses are laid out accordingly and provided with the necessary additional equipment. The product range comprises a large spectrum so that Röcher is in the position to supply its products to a large market segment. This includes both manually operated feeder presses and complete automatic systems. As the dimensions of the presses vary extremely and the scope of supply comprises pure hydraulic presses and also complete systems, the order volumes are very different.

Depending on the intended application, the machines use different equipment, such as one or several hydraulic drawing pads for deep-drawing, hydraulic snap-through dampening, mechanical stroke limitations, ejectors, tool protection system, tool control, hydraulic quick-acting tool clamping device, hydraulic roller strips for ease of tool change, etc.

For all machines, the parameters such as forces, positions, speeds and functions are preselected at the control terminal. Thus, it is possible to store these parameters under a record and retrieve them, if required. This allows for the fast adaptation of the machines.

It is important that hydraulic presses are of solid construction, as these machines represent investments for very long periods of time, i.e. a stiff and fatigue-resisting press frame, precise guidance assemblies, enduring cylinders with thick walls, hydraulic control with appropriate functions and cross sections as well as a reliable electric control that is clear for the operator.


Figure 1: Hydraulic C frame press with guided press carriage
Figure 1 shows a hydraulic C frame press with guided press carriage. Some of the press operators need the accessibility of a C frame press but the accuracy of a standard gap press is not sufficient for them. The guidance accuracy is improved and bending-up reduced thanks to the robust construction and long adjustable guidance assemblies. Thus, the pressing process on this machine can also be carried out with eccentric force.



 Figure 2: Hydraulic double sided press with largely dimensioned long, adjustable eightfold guidance assemblies
Figure 2 shows a hydraulic double sided press with largely dimensioned long, adjustable eightfold guidance assemblies. The guidance assemblies are fitted with wear-resistant bronze strips as, compared to plastics, the guidance accuracy is improved. This type of machine is used both for manual loading and automatic processes including strip processing system, robot or transfer systems. These machines are mainly used with large table surfaces for large-area tools, progressive compound tools or processes where eccentric loads are involved.

Precise pressing processes with hydraulic controls are a particular strength of the machine. Whether it is about precise force controls, controls for the avoidance of pressure peaks, exact positioning or fast synchronisation controls in case of large table sizes with eccentric loads, precision presses are an important part of the delivery program of the Röcher company.

 


Figure 3: Hydraulic punching press with progressive compound tools
Figure 3 shows a hydraulic punching press with progressive compound tools. As the user processes material from a thickness of 0.1 mm, the tool cutting gaps are extremely reduced. Tilting of the ram may thus cause damage to the die. An extremely precise 12-fold roller guide ensures very precise zero-clearance guidance. In addition, the machine is equipped with a hydroelectronic synchronisation control that additionally prevents ram tilting of less than some hundredth millimetres.

 

Röcher attends of course also users of hydraulic presses other than in the field of new machines. Likewise, safety checks, service, rebuilds, modernisations and repairs are carried out on hydraulic presses of all makes. For some users, Röcher presently retrofits machines manufactured in the years 70 with modern electrical and hydraulic controls.

If a user needs a press with strip processing system, it is possible that the customer provides this strip processing system or purchases it directly with the press. Röcher frequently manufactures a press in connection with a roll feed. This is insofar advantageous for the user as the press and the feed are operated via one control with a central operator terminal. This simplifies the setting and improves the survey of the machine. The roll feeds are equipped with an electric servodrive that ensures dynamic and precise transport. In the past, strip processing systems were manufactured for strip thicknesses of up to 8 mm. Roll feeds and strip processing systems are of course also available from Röcher as individual components.

As the company disposes of a large processing spectrum including the required know-how in the field of mechanical, hydraulic, electric engineering and software, Röcher is in the position to manufacture user-specific special presses and systems without any problem.

As a rule, the electrical controls are laid out on the basis of Siemens Simatic S7-300 and S7-400.

As nowadays there is only a limited number of midsize firms that cover everything from the mechanical engineering to the production including but not limited to hydraulic controls, electrical controls and software, Röcher manufactures apart from its usual presses also other special machines, which are laid out according to the individual requirements and products of the user. These can be both series and individual custom-made machines.