Tube and bar grinding, polishing and brushing machines TYPE RS

From the universal compact machine…

The principle of centerless grinding (centerless process) results in rapid finish machining of the outer surface of cylindrical and slightly conical workpieces. For this reason, the compact machine with a universally designed workstation offers an economical solution for many requirements in which frequently changing small series or individual workpieces are processed.
 
Particularly in the case of wet grinding under emulsion supply (Image. 1), a single pass is sometimes sufficient due to the high cutting performance. Alternatively, the operator can move the workpiece through the machining station several times in reverse mode by swiveling the control disk.
 
Higher surface requirements can be met in several passes with abrasive belts of graduated grit sizes, if too high an output rate is not required. Additional passes with cork polishing belts result in a finish that is equivalent to a polished surface in terms of roughness. The fast belt change has a very advantageous effect here.
 
The adapted cyclone filter device for emulsion grinding is supplied by us (Image. 1).
 
On the other hand, plastic-bonded grinding wheels or polishing wheels of various types can also be used in the belt grinding protective hood, which can be replaced in minutes. The adjustment device to compensate for the wear of the pulleys is present in all cases. The spraying device required for applying modern liquid pastes (Image. 2) can be additionally attached to the belt grinding station. The liquid polishing paste is fed to the spray gun from a pressure vessel at adjustable time intervals.
 
However, if it is clear from the outset that only cloth polishing wheels, elastic grinding wheels, brushes etc. will be used, then the belt grinding arm can be dispensed with. are used, then the belt grinding arm can be dispensed with and a special polishing protection hood can be used (Image. 3). The hood has a nozzle for connecting a dust extraction pipe.

Automatic loading and unloading systems for optimum material flow 1. Diabolo roller transport ( type ABE-R)

For processing large numbers of pieces or long tubes, it is advisable to use a loading and unloading device that automatically separates, feeds and discharges the workpieces after magazine loading and places them on the unloading table. The material to be processed is placed on the loading table (Image. 4) (e.g. by the factory crane) and rolls against the separating discs of the loading roller table due to the slight inclination of the table. In their pockets, the discs arranged on a continuous shaft pick up the workpieces one by one, swivel them around the shaft and deposit them on the roller table. The V-profile of the Diabolo rollers centers the workpieces for entry into the main machine. The infeed speed can be varied by continuously adjusting the roller speed.
 
With an additional feed unit on the machine infeed side, the workpieces can be fed in rotation (option, see cover picture).
 
Die Werkstückvereinzelung wird durch Sensorüberwachung des Werkstückeinlaufs in die Hauptmaschine elektronisch ge- steuert. From the unloading roller table, the workpieces are removed in the same way by means of lifting discs and deposited on the unwinding table.
 
For large-scale production, an automatically operating pipe coil lifting trough can be connected upstream of the loading device (Image. 5).

2. belt transport (type ABE-G)

For lighter pipes with diameters up to 40 mm and short bars, a simple loading and unloading combination with transport belt system is suitable (see also Fig. 10).
 
In this system, too, the workpieces are placed on an inclined support table and separated by means of separating discs. However, the infeed into the main machine is not via rollers, but via a plastic transport belt with continuously adjustable speed. The rhythm of the allocation is sensory controlled. After a workpiece has passed, the proximity switch on the machine infeed side gives an impulse to the pneumatic swivel drive of the separating discs (see Image. 7).
 
At the exit of the machine, the workpieces are taken over by a transport belt and unrolled via a deflector or pneumatic pusher into a deposit trough The pusher is controlled via a second sensor at the exit (see Image. 8).

…to the customized fully automatic machine

The machines in the RS series are modular in design and can therefore be expanded at a later date as automation requirements increase.
 
However, if the output requirements are high from the outset, it is advisable to use a fully automatic machine tailored to the specific production conditions. This includes a number of work stations to be determined in project tests, which ensure the required surface quality of the workpieces at a given transport speed in one pass. Added to this are the loading and unloading devices tailored to the workpiece dimensions and weights (see pages 2 and 3). In many cases, 5-station machines have proven their worth, producing a chromium-plated surface in a single pass for today’s standard pipe qualities.
 
The example shown in Image. 9 shows a 5-station belt grinder with ABE-R loading and unloading combination, with which 2000 m of furniture tubes with grit sequence 150, 240, 320, 2 times SF 400 are ground ready for chrome plating in an 8-hour shift.
 
Image. 10 shows a 5-station belt grinder with which 6000 shock absorber tubes are ground ready for chrome plating in a single shift. The ABE-G loading system is preceded by a 2-chamber magazine for alternate left/right feeding of the conical tubes.

Ideal running properties

The working units of the RS machine type are characterized by their stable and compact design. Each workstation consists of
 
Work spindle slide with three-phase drive motor, two-stage V-belt power transmission to the separate work spindle, with belt grinding or polishing wheel protective hood, overall adjustable via square spindle for adaptation to different wheel diameters as well as readjustment in case of polishing wheel wear.

Belt grinding units additionally have a belt tensioning arm mounted above the work spindle, which is equipped with a quick-action tensioning lever for belt change and belt run regulation by means of a handwheel.

Control wheel slide with separately driven control wheel and the adjustment mechanisms for contact force, workpiece diameter, feed direction and speed

Together with the well-known damping properties of the material gray cast iron, in which all essential components of the working unit are made, the generously dimensioned design results in the quiet and trouble-free running that is appreciated worldwide on CRElF centerless grinding and polishing machines.

The workpiece is fed through the work stations using the classic centerless method. The workpiece is guided over a support ruler and pressed against the regulating wheel with greater force due to its eccentricity between the polishing wheel and regulating wheel. In this case, the control wheel axis is inclined by a few degrees against the workpiece axis in accordance with the required throughput speed, which creates an axial force component that causes the longitudinal feed.