EoW March 2007

fasteners & spring production

Expertise and a range of machines from Kamatech

Kamatech provides a range of horizontal spring end grinder machines which have horizontally installed grinding spindles. The two main advantages of this structure are that the spring’s weight does not influence the grinding result and that working in down-feed grinding mode is easy as the spindle slides only have to advance against the increasing grinding pressure. Grinders with pendulum frame : The pendulum slide makes the down feed movement. The movement is controlled by electronic units that regulate the speed and force of the wheel . The total grinding time depends on the pressure, and the remaining spark- out time. As the grinding fluid is a water and oil emulsion, the grinding wheel residue has to be disposed of separately. Only regular cleaning can prevent encrustation of the collet chuck. Vertical spring end grinder machines : Vertical spring end grinders have vertically installed grinding splindles. Compared to horizontal grinders, vertical spring end grinders have two decisive advantages: During the loading process the spring positions itself by its own weight; Better accessibility of machine and loading plate. • •

P1000 Kamatech with pendulum frame

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Between the wheels it turns a steel disc which charges the springs with manual loading or the automatic loading unit. There are two different types of work for grinding the spring – crush grinding and down-feed grinding. Crush grinding :

In crush grinding, grinding wheels are not fed down and the required spring length is ground in one pass. Loading plates rotate with constant, slow speed or a sequential indexing motion, while loading and grinding takes place simultaneously. This cycle is only used for wire diameters toward the smaller end of the machine’s wire diameter range. Down-feed end grinding : In this type of cycle there is a constant advance of one grinding wheel. In order to grind springs to the desired length, the springs make numerous passes between the wheels as the down-feed progresses. This down-feed movement is proportional to the grinding force and is regulated by electronic control. The loading plate rotates with constant and high speed, while loading and grinding take place successively. Today in down feed-grinding the down feed movement is carried out in several, easily programmable steps finishing with a sparking-out period.

Page for down feed program

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The wheels for springs end grinders : Variable wheels in the working of springs determine the choice of more suitable wheels.

This choice includes:

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Material of the springs; Diameter of the wire; Rigidity of the springs; System of refrigeration.

The job surface must be unloaded, in order to reduce the chances of overheating. This is better achieved by using larger grain wheels in relation to the demanded finish. Grinding wheel dressing : The spring end grinder needs dressing when it is worn down so that it can retain cutting efficiency. Dressing serves to sharpen and profile the grinding wheel. The sharpening includes the change of micro topology by exposing new grain and pores, while in profiling

Kamatech dresser unit for spring end grinder machine

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the grinding surfaces are reshaped. For spring-end grinding only the face of the wheel is dressed. Poorly executed wheel dressing reduces overall efficiency of the machine and operation cycles will be shorter because dressing will have to be performed more frequently. Wheel life will also be shorter because more unused material will be wasted. Before multi-layered grinding wheels are used for the first time they have to be conditioned. Kamatech – Italy Fax : +39 0342 691043 Email : info@kamatech.it Website : www.kamatech.it

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EuroWire – March 2007