DE102010011634B3 - Method for measuring small and fine cutting edge geometry of rotation symmetrical drilling and milling tool for milling/drilling work-piece in dental area, involves measuring angle difference between starting and end positions of tool - Google Patents

Abstract

A method for measuring the cutting edge geometry of drilling and milling tools, in particular the rake angle w provides a microscope 10, by means of which the cutting edge geometry is measured.

Description

The invention relates to a method for measuring the cutting edge geometry of drilling and milling tools according to the preamble of claim 1.

There are various measuring devices with which the cutting edge geometries of rotationally symmetrical drilling and milling tools can be determined and measured. With large drilling and milling tools, it is possible to cut off the cutting edges with a button or to create a ruler. However, this is no longer possible with very small drilling and milling tools and with fine toothing geometries, for example in the dental field. Often then the drilling and milling tool must be separated, for example, to be able to determine the rake angle, the clearance angle and the tooth depth of the cutting edge. Since this finished and usually sellable drilling and milling tools must be destroyed, this represents a major cost factor. Also problematic is the edge shape. This rarely consists of straight surfaces and is usually concave or convex. This means that one can only approach the actual angle in the case of determining the rake angle of the drilling and milling tool. However, the rake angle is of particular importance for the cutting properties of the drilling and milling tool.

The DD 41 790 A1 shows an optical rake for measuring the rake angle at a certain point of a tool of the type specified. The tool is fixed between its tips. Using a slit projector, a fine light gap is projected onto the tool. So that the slit image also reaches beveled cutting edges, the slit projector is inclined by an angle in the vertical. With a sliding microscope, the slit image is grazing on the tool. In the field of view of the microscope, the profile image of the cutting edge is then measured with a calibrated scale.

The GB 102 652 A shows the use of a microscope to measure cutting geometries. For example, the opening angle of the teeth of a thread can be measured. For this purpose, the workpiece is clamped. By adjusting the microscope, it is aimed along the flanks of the teeth. The angular difference between the two microscope positions is then measured. This measured value corresponds to the opening angle of the tooth flank.

The DE 69 12 042 U shows an apparatus for measuring small diameter spiral drills by means of a measuring microscope. The microscope is fixed in position. The drill to be examined is fixed to an angle piece mounted on the microscope stage. By this angle piece is set up differently, the drill can be measured. The tip of the drill is in the respective positions with respect to the microscope always in the same place.

The DE 837 015 B shows a cutting angle microscope. In this case, the cutting tool to be examined is placed on a hollow prism-shaped tool carrier. The cutting edge of the tool is aimed at with a line cross of the microscope. By turning a dial then the measured angles can be read.

The DE 102 12 004 A1 shows a method and apparatus for detecting at least a portion of a workpiece or a tool. By a sharp image of the workpiece by means of a microscope objective at different locations while the path difference and thus a certain length can be measured.

The DE 10 2007 053 993 A1 shows a method and an apparatus for tool measurement, in particular the cutting edges of tools. The tool is rotated while taking pictures. From these, the data of the cutting edge can then be extracted.

The invention has for its object to provide a quick, simple and comprehensive review of the cutting geometry of rotationally symmetric drilling and milling tools of the type described, which in particular allows to monitor the production process of such drilling and milling tools promptly and non-destructively.

The technical solution is characterized by the features in the characterizing part of claim 1.

As a result, a method for measuring the cutting geometry of drilling and milling tools is provided which, after the production of the drilling and milling tool before use a quick, simple and comprehensive review of such rotationally symmetric drilling and milling tools creates, which makes it possible the production process of this Monitoring drilling and milling tools promptly and non-destructively. The basic idea is that a measuring microscope is used. This measuring microscope is universally applicable. In particular, with this measuring microscope it is possible to measure the cutting geometry directly by optical control. This measuring microscope is preferably adjustable along its optical axis, and also perpendicular to this optical axis. This can be done easily by hand through appropriate wheels. The above-described directions of movement corresponding electronic encoder are assigned, so that in a simple way path differences can be measured. The corresponding electronics for these referenced encoders is preferably resettable to zero in any position. The measurement data obtained with the measuring method according to the invention can be displayed and read by means of a corresponding display. It is also possible for the measured data to be supplied to corresponding data processing. In addition, there is also the possibility of connecting a digital camera to the microscope in order to thus couple the measuring microscope with a screen display. The basic idea according to the invention for measuring the cutting angle of the cutting edge of the drilling and milling tool is that with respect to a crosshair of the microscope objective, which defines the optical axis, two different geometric positions are set, from whose difference the rake angle can be derived. It is essential that the rotary bearing of the drilling and milling tool, in particular the chuck has a rotary encoder. This means that the angular difference between the starting position and the end position can be measured electronically.

According to the embodiment in claim 2, the measuring microscope preferably has different magnification levels. For this purpose, a lens revolver arranged on the microscope can be provided. These different magnification levels can be swiveled in via the nosepiece.

The development according to claim 3 proposes that a shank of the drilling and milling tool is set in a rotatable chuck. In this chuck, the shaft end of the drilling and milling tool is clamped. A built-in torsionally rigid coupling prevents running inaccuracies of the chuck from adversely affecting the concentricity of the drilling and milling tool.

The development according to claim 4 proposes that the end face of the drilling and milling tool rests against a stop. As a result, on the one hand given a support, on the other hand is defined by the stop, at which distance from this stop the survey is performed.

The development according to claim 5 proposes a so-called prism bearing for the shank of the drilling and milling tool. The shaft rests on a V-shaped support of this prism bearing. By a screw while the shaft is determined without play. Nevertheless, the drilling and milling tool is rotatable. This V-shaped support has the advantage that the central axes of the drilling and milling tool are always perpendicular to each other with different shank diameters, without transverse offset.

Since in the above-described measuring method of the rake angle, the alignment of the rake face of the tooth is essential, the development proposes according to claim 6 that this rake face is illuminated. As a result, their end position, in which the optical axis of the microscope lies exactly in this rake face, can be accurately recognized by the observer through the microscope.

The development according to claim 7 proposes a measuring method for measuring the depth of the tooth of the cutting edge. Here it is assumed that the optics of the microscope has a fixed focal length. By adjusting the optics along its optical axis, different positions along this optical axis can thereby be focused. This is used to measure the depth of the tooth by focusing the cutting edge during the first measurement, thereby defining the zero point and focusing the bottom of the tooth on the second measurement. Again, the microscope along the movability of the optical axis on a displacement sensor. This means that the path difference between the starting position and the end position can be measured electronically.

Furthermore, the development proposes according to claim 8, that the spiral angle of the cutting edge can be measured. For this purpose, the see-through optics of the eyepiece, for example, has a crosshair, along which the cutting edge can be aligned by the eyepiece is rotated accordingly. By a corresponding angle display, the spiral angle can then be determined exactly.

The development according to claim 9 proposes a way to measure the distances of adjacent cutting edges of the drilling and milling tool.

Finally, the development according to claim 10 proposes a Feinmeßtaster, which makes it possible to measure the concentricity of the drilling and milling tool or the tool blank. This is due to the corresponding position of the tool. Corresponding deflections are detected and displayed by the fine probe. By this Feinmeßtaster is arranged on the Verfahrgestell of the microscope, the Feinmeßtaster can be moved so that it detects the largest possible Ausschlagsposition of the tool.

An embodiment of an apparatus for carrying out the measuring method according to the invention for the cutting edge geometry of a drilling and milling tool will be described below with reference to the drawings. In these shows:

1 a perspective view of the device;

2 a detail of the device in 1 with clamped drilling and milling tool;

3a a cross-sectional view through the pipe and milling tool to be measured in the Ausgangsmeßposition;

3b a cross-sectional view through the pipe and milling tool to be measured in the Endmeßposition.

On a base plate 1 The device is a clamping device 2 with a chuck 3 for the shaft 4 a drilling and milling tool to be measured 5 , This clamping device 2 is along a guide 6 moveable and fixable by means of screws.

On the opposite side of the guide 6 the base plate 1 there is a stop 7 for the frontal head of the drilling and milling tool 5 , This stop 7 is arranged on a corresponding device, which along the guide 6 movable and also fixable by means of screws.

Between the clamping device 2 and the stop 7 There are two V-shaped shots 8th for the shaft 4 of the drilling and milling tool 5 , The fixation of the shaft 4 of the drilling and milling tool 5 in these V-shaped shots 8th done by screws 9 , However, these are so attracted that the drilling and milling tool 5 still lets turn.

Furthermore, a microscope 10 intended. This is at a corresponding facility on the base plate 1 attached.

Finally, at the base plate 1 a micrometer 11 and on the holding device for the microscope 10 a Tastmeßeinrichtung 12 arranged.

With the device to the rake angle w of a tooth 13 of the drilling and milling tool 5 be measured. The functionality is as follows:
First, the drilling and milling tool 5 with his shaft 4 in the chuck 3 the clamping device 2 fixed. This is the clamping device 2 first to the diameter of the shaft 4 of the drilling and milling tool 5 adapted by the shaft 4 between predetermined setting surfaces 14 the clamping device 2 is held and attached to a driver unit 15 arranged clamping device 2 is moved in accordance with the shift arrow W until the setting surfaces 14 on the shaft 4 the milling device 5 issue. In this position, the driver unit 15 with the help of a clamping lever 16 fixed.

Then the shaft is 4 of the drilling and milling tool 5 in the provided V-shaped recordings 8th inserted and with the help of screws 9 pressed into the prism bearing without play. By moving the clamping device 2 along the guide 6 along the sliding arrow X and pressing the chuck 3 is then the drilling and milling tool 5 with his shaft 4 fixed.

The measuring position is - from the top of the drilling and milling tool 5 seen from - by the stop 7 adjusted by means of a measuring point scale.

Thus, all in all, the drilling and milling tool to be measured 5 brought into the survey position, so that the actual measurement can be started.

This is the microscope 10 moved by moving along the displacement arrow Y in a position in which the optical axis 17 of the microscope 10 exactly through the central axis 18 of the drilling and milling tool 5 goes. For this purpose, the stop 7 be provided with a corresponding mark, which seen in the vertical direction exactly above (ie without lateral offset) of the central axis 18 of the drilling and milling tool 5 lies. This Y value is stored as a zero point and can thus be adopted for subsequent measurements.

The drilling and milling tool 5 is now rotated so that the edge to be measured with its cutting edge 19 exactly on the optical axis, ie in the crosshairs of the lens of the microscope 10 lies. This can be done by the operator by looking through the eyepiece of the microscope 10 to adjust. Focusing takes place along the displacement arrow Z. This is then the starting position, as in 3a is shown. In this position, the rotary encoder of the chuck becomes 3 set to zero.

Subsequently, the chuck 3 rotated, as indicated by the rotary arrow A. The goal is that the rake face 20 exactly in the optical axis 17 of the microscope 10 lies. This is due to an interplay between the turning of the chuck 3 according to the rotary arrow A and the adjusting movement of the microscope 10 along the displacement arrow Y possibly reached under new focus along the displacement arrow Z. Because the chuck 3 equipped with a rotary encoder, the angle of rotation of the chuck can 3 are measured, which corresponds to the rake angle w.

By means of the described device also other measurements are possible.

So it is possible the depth of the tooth 13 to eat. This is done by the microscope 10 by adjusting along the displacement arrow Z once on the cutting edge 19 and the other on the floor of the tooth 13 in focus. By a corresponding sensor along the displacement arrow Z can then the path difference and thus the depth of the tooth 13 be determined.

Also the spiral angle of the drilling and milling tool 5 can be determined. For this purpose, the eyepiece of the microscope 10 rotated according to the rotary arrow B. In the eyepiece is a marker which tangent to the cutting edge 19 can be placed. The corresponding angle can then be determined.

By means of the Tastmeßeinrichtung 12 Finally, there is the concentricity of the drilling and milling tool 5 be checked by this Tastmeßeinrichtung 12 is brought into contact accordingly.

In the illustrated embodiment, the cutting edge, in particular its rake face in the area of the lateral surface was measured. But it is also conceivable to measure according to the same principle, a frontal cutting edge of the drilling and milling tool. In this case, then in the initial position, the central axis of the drilling and milling tool is not perpendicular, but parallel to the optical axis of the microscope 10 , For the second measuring position then this central axis is tilted slightly.

LIST OF REFERENCE NUMBERS

1

baseplate

2

tensioning device

3

chuck

4

shaft

5

Drilling and milling tool

6

guide

7

attack

8th

V-shaped recording

9

screw

10

microscope

11

micrometer

12

Tastmeßeinrichtung

13

tooth

14

setting surface

15

Driver unit

16

clamping lever

17

optical axis

18

central axis

19

cutting edge

20

clamping surface

w

rake angle

A

rotation arrow

B

rotation arrow

W

displacement arrow

X

displacement arrow

Y

displacement arrow

Z

displacement arrow

Claims (10)

Method for measuring the cutting geometry of drilling and milling tools ( 5 ), in which by means of a microscope ( 10 ) the rake angle (w) of the cutting edge of the drilling and milling tool ( 5 ) is measured, characterized in that first the drilling and milling tool ( 5 ) is aligned so that the cutting edge ( 19 ) of the cutting edge and the central axis ( 18 ) of the drilling and milling tool ( 5 ) in the optical axis ( 17 ) of the microscope ( 10 ), then that the drilling and milling tool ( 5 ) and either the microscope ( 10 ) or the drilling and milling tool ( 5 ) perpendicular to the optical axis ( 17 ) of the microscope ( 10 ), that the rake face ( 20 ) in the optical axis ( 17 ) of the microscope ( 10 ), with an operator looking through an eyepiece of the microscope ( 10 ) the adjustment operations optically controlled, and that a rotational angle difference between the starting position and the end position of the drilling and milling tool ( 5 ) is measured. Method according to the preceding claim, characterized in that the microscope ( 10 ) has different magnification levels. Method according to one of the preceding claims, characterized in that a shaft ( 4 ) of the drilling and milling tool ( 5 ) in a rotatable chuck ( 3 ). Method according to one of the preceding claims, characterized in that the end face of the drilling and milling tool ( 5 ) at a stop ( 7 ) is present. Method according to one of the preceding claims, characterized in that a shaft ( 4 ) of the drilling and milling tool ( 5 ) on a V-shaped receptacle ( 8th ) and on this by means of a screw ( 9 ) free of play, but rotatably fixed. Method according to one of the preceding claims, characterized in that the clamping surface ( 20 ) is illuminated. Method according to one of the preceding claims, characterized in that for measuring the depth of the tooth ( 13 ) the cutting edge of the drilling and milling tool ( 5 ) the optics of the microscope ( 10 ) first the cutting edge ( 19 ) of the cutting edge and then the tooth base of the tooth ( 13 ), wherein between the initial position and the end position of the microscope ( 10 ) a path difference is measured. Method according to one of the preceding claims, characterized in that for measuring the spiral angle of the cutting edge with respect to the central axis ( 18 ) of the drilling and milling tool ( 5 ) the eyepiece of the microscope ( 10 ) has a marker or a rotary encoder, wherein the eyepiece from the parallel position with respect to the central axis ( 18 ) of the drilling and milling tool ( 5 ) in the tangential parallel position to the cutting edge ( 19 ) is rotated and wherein the rotational angle difference between the starting position and the end position is measured. Method according to one of the preceding claims, characterized in that for measuring the distances of adjacent cutting edges ( 19 ) of the drilling and milling tool ( 5 ) first the drilling and milling tool ( 5 ) is aligned so that the first cutting edge ( 19 ) in the crosshairs of the microscope ( 10 ) and then that the drilling and milling tool ( 5 ) is rotated such that the second cutting edge ( 19 ) in the crosshairs of the microscope ( 10 ), wherein the rotational angle difference between the starting position and the end position of the drilling and milling tool ( 5 ) is measured. Method according to one of the preceding claims, characterized in that a tactile measuring device ( 12 ) for scanning the concentricity of the drilling and milling tool ( 5 ) is used.

Images