DD236228A3 - METHOD AND TOOL HOLDER FOR WORKING PROFILED LATERAL REMOVAL IN RINGNUT OF TURBINE COMPONENTS - Google Patents

Abstract

The invention particularly relates to recesses which are to be incorporated in turbine parts for foot mounts of turbine blades on conventional lathes with interchangeable turning tools in narrow annular grooves. The aim and task is to simplify the induction procedures and to avoid sources of error in the processing of the opposite recesses, with regard to their exact location. This is achieved by positioning the tool in the axis-parallel working plane of the recesses to be machined with the plan support. While maintaining this position, the work processes following in the same working plane are incorporated only by advancing movements of the transverse support or the longitudinal slide. There is at least a front and rear open tool holder used. Fig. 1

Description

-2- 700

3: the front view of the clamped tool holder with lathe tool according to FIG. 2; 4 and 5: arrangement variants of the position element.

In a turbine runner 1 are fir-tree profiled annular grooves 2 (circumferential grooves) as a foot holder for not shown, highly stressed turbine blades to incorporate. The annular groove 2 is radially inwardly, according to the dashed contour 3, stepwise deducted according to the Christmas tree profile prepared. In a plurality of operations, the mirror-like recesses of the annular groove 2 are then machined in the machining planes 4, 4 ', 4 ", using hook-shaped turning tools 1 on the left or right side, which are held in a tool holder held in a tensioning device 6 of a crosshead support (not shown) 7. For the incorporation of the lateral mirror-inverted recesses, the turning tool 5 is driven with the likewise not-shown planar support into one of the axially parallel machining planes 4, 4 ', 4 "and positioned there. In the position shown in FIG. 1, in the plane 4, the recess corresponding to the dashed contour on the left side vorzuarbeiten. This is followed by the training on the opposite side, only by using an analogous mirror-image lathe tool while maintaining the position of the plan support. It is immaterial to the application of the method whether, as shown in Fig. 1, the turning tool only a hook-shaped or, as not shown, a plurality of hook-shaped cutting, with which, for example, in all three processing levels 4, 4 ', 4 "on One side recesses are processed simultaneously with a lateral feed movement.

The latter procedure is dependent on the size of the entire Christmas tree profile. It is essential that the incorporation of the opposite recesses with respect to the previously processed, while maintaining the position of the plan support in the working plane of the recesses, is made.

According to the invention, each turning tool 5 used is fastened in a tool holder 7 which is open at least forwards and backwards and which has a defined releasable position element 9 for the turning tool 5. After removing the position element 9 and loosening the clamping screws 10, the turning tool 5, while maintaining the position of the plan support in one of the processing levels 4,4 ', 4 ", only pulled backwards out of the annular groove 2 and against the one for the next All of the lathe tools 5 used for the preparation of the lateral recesses have a fitting bore 11 receiving the position element 9, the shaft passing through the shaft or a fitting bore 11 'cutting the shank, It is also possible to arrange a fitting bore 11 "in the tool holder such that that the position element 9 limits the position of the turning tool 5 to the rear stop. The position element 9 may be cylindrical or conical, it may also be a Paßkeil. Finally, it is also possible to choose the position for the position element 9 deviating from the illustrated, horizontal or otherwise.

The method and the tool holder can not only be used in annular grooves of turbine parts, they can be used anywhere where within an axis-parallel working plane with tools moving in a tool slide, on either side or one side in narrow grooves lateral recesses are incorporated in more than one operation.

Documents considered:

DRP 219 892 (49a, 25). , .

Claims (2)

-1- 700 Invention claim: 1. A method for incorporating profiled, in particular mirror-image recesses in lateral annular groove walls of turbine rotors, wheel disks, guide vanes and nozzles for foot supports of turbine blades on conventional lathes, wherein in a single clamping of the workpiece a plurality of successive operations are provided for incorporation using a on a Cross support mounted tool holder, in which a replaceable clamped lathe tool is arranged as a tool, characterized in that the tool is positioned in the working plane of the incorporated lateral recesses with the plan support and that while maintaining this position, in the same axis-parallel working plane following operations by moving the Cross supports or longitudinal slides are incorporated. 2. Tool holder for carrying out a method according to item 1, characterized gekennzeichnt that the tool holder (7) has an at least fore and aft open Drehmeißelaufnahme. For this 1 page drawings field of use The invention relates to a method and a tool holder for incorporating profiled, in particular mirror-image recesses in lateral Ringnutenwandungen of turbine rotors, wheel discs, guide vanes and nozzles for foot holders of turbine blades on conventional lathes, being provided in only one clamping of the workpiece several successive operations for incorporation using a mounted on a cross support tool holder, in which a replaceable clamped turning tool is arranged as a tool. Characteristic of the known technical solutions It is known, lateral profiled recesses, for example, fir-profiled or hammerhead profiled recesses, which require a very high machining accuracy for highly stressed foot mounts of turbine blades to incorporate on conventional lathes. According to the method, separate operations are provided, for example, for the pre-processing, finishing and finishing. For each of these operations, the plan support in the working plane with the newly clamped tool has always been repositioned since the tool was moved out of the annular groove for replacement with the plan support. In both sides mirror images to be incorporated recesses means that in the relevant axis-parallel machining plane six times changed the tool and thus six times the plan support was repositioned in the working plane. In a Tannenbaumfuß-ring groove with three superimposed support flanks even an eighteen-time tool change including the positioning effort according to the previous processing method is necessary. In order to comply with the very tight tolerances with respect to the exact mirror image position opposite lateral recesses to be incorporated, the plan support is retracted, for example, with dial gauges to the working plane. The basis for this is formed by the reference surfaces which have been worked in addition to the annular groove. Internal inaccuracies, such as existing games in the delivery devices of the lathes, complicate compliance with the required tolerances. All previously known, provided with prismatic shaft tool holder and turning tool designs require a retraction of the turning tool from the annular groove when the tool is replaced, since both side, as well as radially inward, due to the Ringnutabmessungen the tool change is not possible. Object of the invention It is to develop a more rational method for incorporation lateral recesses for the application mentioned above. Explanation of the essence of the invention The task is to reduce the time required for the repeated positioning of the tool in the axis-parallel working plane for subsequent operations and to avoid sources of error in the processing, in particular opposite recesses in terms of their exact location. According to the method, this object is achieved in that the tool is positioned in the axis-parallel working plane of the incorporated lateral recesses with the plan support and that while maintaining this position in the same axis-parallel working plane subsequent operations are incorporated only by feed movements of the transverse support or the longitudinal slide. In a trained for performing the method tool holder, the tool holder has an at least front and rear open receptacle provided with prismatic shaft and with known releasable defined position elements lathe tool. The advantage of the invention consists in particular in the fact that the time required for the repositioning of the tool after the tool change is substantially reduced and that compliance with the required tolerances with respect to the position of opposing support flanks is facilitated. embodiment The invention is explained in more detail below using an exemplary embodiment. In the accompanying drawing show: Fig. 1: an outbreak from the longitudinal section at the Ringnutstelle a turbine rotor with retracted lathe tool;