Spring-loaded guide pads for reliable machining of large boring depths

(PresseBox) (Aalen, ) There is often a lack of mature tool solutions when it comes to the machining of bores with medium to large diameters and long projection lengths. With the development of "spring-loaded guide pads", MAPAL has brought a concept to the market (patent pending) that makes these machining operations significantly more productive and more reliable.

Conventional machining methods do not offer satisfactory solutions for the machining of large and long bores. Two fundamental difficulties make the production slow and impair the process reliability: First, the long projection lengths of the tools in conjunction with a large tool head lead to a high tendency to vibrate. Single or twin-bladed spindle tools with low dead weight are therefore generally used. A disadvantage here are the low cutting speeds that result in long machining times. The second difficulty lies in the raw part that frequently exhibits large inhomogeneities in the material, and hence requires different stock removals. This all makes great demands on the tool used.

Spring-loaded guide pads allow smooth machining and high cutting rates
The new machining solution increases the process reliability and significantly accelerates the machining. The modular tool concept combines the tangential with the guide pad technology. The tool head can be fitted with up to eight indexable inserts. A combination of conventional, fixed brazed and innovative, spring-loaded guide pads ensures the stability and reliability of the machining operation. Depending on the actual number of blades, a computation program developed by MAPAL calculates the direction of the resulting cutting force. The two fixed brazed guide pads are fitted to the left and right of the force direction. The spring-loaded guide pads are then positioned on the opposite side at a certain distance from the indexable insert. They support the resulting cutting force and ensure that the fixed guide pads lie perfectly against the material of the bore in order to perfectly support the tool. Smooth machining and high cutting rates are the result.

Modular extensions for large boring depths
Modular attachable extensions allow practically any boring depth to be achieved even with limited travel distances. The HSK interface stands for the absolute precision of the connection. In order to install an extension, the tool does not even have to be completely removed from the bore and can be held in the bore by means of a tool support. An optimum cylindrical form of the bore is thus assured and the maximum possible boring depth is essentially only limited by the dimensions of the working space.

Successful in practice
In one concrete application, the machining took several days. A further working day had to be planned for the subsequent honing process. With the tool solution from MAPAL, the customer receives a reliably machined workpiece with perfect diameter and surface finish. Machining takes four to six hours, the subsequent honing two to three hours.


MAPAL Dr. Kress KG
Obere Bahnstr. 13
D-73431 Aalen
Andreas Enzenbach
Leitung Marketing und Corporate Communications
Kathrin Rehor
Corporate Communications
PR Fachpresse


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