Special report:
BBR - Bänder, Bleche, Rohre (09-2003)

From manual to fully automatic

From manual to fully automatic

From the hydraulic press to the customer-specific system

Whether it is about punching, drawing, stamping, bending, sizing, inserting, bordering, trimming, straightening or assembling, a machine builder from Netphen-Deuz covers the entire range of the forming technique. The professional magazine Bänder Bleche Rohre (BBR) introduces the company and some of its highlights from the individual press to the customer-specific system.

Röcher Maschinenbau, a manufacturer of hydraulic presses, special machines as well as machines for strip processing offers various equipment, the special strength of the company being the area of precise pressing processes with hydraulic controls. Customer proximity is also a moulding factor for this company and enables it to serve a large market segment. The spectrum extends from manually loaded presses as far as complete automatic systems.

Mechanical engineering related to need

Depending on the application, the machines use different equipment, such as one or several drawing pads for deep-drawing, hydraulic snap-through dampers for punching, mechanical stroke limitation, ejector, tool protection, tool control, hydraulic quick-acting tool clamping device, hydraulic roller strips for easy tool change, etc. For all machines, the parameters such as forces, positions, speeds and functions are selected on the operator terminal. Thus, it is possible to store these parameters under a data record and retrieve them, if required. This ensures a fast retooling of the machines.

As these machines represent investments for very long periods of time, it is important that hydraulic presses are of robust construction, 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 well comprehensible for the operator.


Hydraulic C frame press with guided press carriage made by Röcher, Netphen-Deuz 

Presses for every application

Röcher manufactures for instance a hydraulic C frame press with guided press carriage. As some press owners need the accessibility of a C frame press but the accuracy of a standard single-press frame with round guidance assemblies is not sufficient for them, the robust construction and long, adjustable guidance assemblies of the Röcher C frame press have improved the guidance accuracy, bending up being reduced at the same time. Consequently, this machine can also be used for pressing with eccentric force.



Hydraulic double sided press with largely dimensioned long, adjustable eightfold guidance assemblies

Another example from the production program of the Westphalians is a hydraulic double-column press with largely dimensioned long, adjustable eightfold guidance assemblies. The guidance assemblies are provided with wear resistant bronze strips, as compared with plastics this improves the guidance accuracy. This machine is used both for manual loading and automatic processes with strip processing system, robot or transfer system. These presses are often used with large table surfaces for large-area tools, progressive compound tools or processes where eccentric loads are involved.


Another version is the hydraulic column press with internal ram, external ram and drawing pad. This type of machine is best suitable for processes involving long strokes and centric load.
Precise pressing processes

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

An example for these precision presses is a hydraulic press for punching using progressive compound tools. As the customer processes material from a thickness of 0.1 mm, the tool cutting gaps are extremely narrow. Tilting of the ram can thus cause damage to the tool. An extremely precise 12-fold roller guide provides for an exact guidance free of any clearance. In addition, the machine is equipped with a hydroelectronic synchronisation control that additionally prevents ram tilting of less than some hundredth millimetres.


This hydraulic press for punching with progressive compound tools uses a hydroelectronic synchronisation control that prevents ram tilting.
Retrofit of foreign makes

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.

Even in special cases

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. In most cases Röcher 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 8 mm. Roll feeds and strip processing systems are of course also available from Röcher as individual components.

As the company disposes of a wide processing range 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.

So for instance a fully automatic customer-specific punching system that is able to notch, perforate, stamp a steel strip and cut it to length. All of the parts belong to one product family. Strip width and thickness are identical for each part but the length varies. As only a small number of units is produced, the retooling times should be minimised as far as possible whereas perforation, notching and stamping of the different parts are recurrent operations and only the quantity, arrangement, etc. change. A requirement of the customer was a high accuracy of the parts.


This fully automatic punching system that can notch, perforate, stamp a steel strip and cut it to length is another solution for one of Röcher's customers.
Directly from the coil

Röcher developed a fully automatic machine that, in contrast to nibbling machines frequently used for processing workpieces from metal plates cut to size, processes parts unreeled from a coil. Essential components of the configurated system are a decoiler, straightening machine, strip stock pile with strip loop control, roll feed with servocontrol, 10 stations as hydraulically operated notching, perforating and stamping units, cutoff shear as well as CNC control with tool magazine for the respective workpieces.

A special feature of the machine is that no retooling is necessary when changing the product. The production process is determined by the sequence of different types of workpieces entered in each case in the CNC control. Thus, the quantity defined in each case for up to 20 different workpiece versions can be produced without any interruption. If required, the parameters can be defined by a central computer and/or the operating data can be evaluated in the computer. The CNC control automatically calculates the production process and includes moreover a clear, detailed and easily comprehensible display, failure analysis and data saving program for monitoring the system.


Röcher supplied this fully automatic system of 50 m in length for splitting, straightening and deburring special sections. The system is equipped with bundle feeding, cross conveyor, roller beds, inlet guides, collecting tray, straightening machine, separating rollers, splitting shear, scrap crusher, deburring shear and complete electric control.

 

This customer-specific fully automatic system for splitting, straightening and deburring of special sections, which is a job-work, indicates that the company is also familiar with the manufacture of special machines. Röcher supplied the system with bundle feeding, cross conveyor, roller beds, inlet guides, collecting tray, straightening machine, separating rollers, splitting shear, scrap crusher, deburring shear and complete electric control.