EP1846187A2

EP1846187A2 - Tool for finely machining boring surfaces

Info

Publication number: EP1846187A2
Application number: EP06706338A
Authority: EP
Inventors: Dieter Kress; Friedrich Häberle
Original assignee: Mapal Fabrik fuer Praezisionswerkzeuge Dr Kress KG
Current assignee: Mapal Fabrik fuer Praezisionswerkzeuge Dr Kress KG
Priority date: 2005-02-04
Filing date: 2006-01-20
Publication date: 2007-10-24
Also published as: WO2006081954A3; WO2006081954A2

Abstract

The invention relates to a tool (1) which is used to machine boring surfaces in a precise manner, comprising a blade plate (5) having at least four geometrically defined blades (9, 9'), whereby two are arranged on the front side (11) and two are arranged on the rear side (53) of the blade plate and at least two guide rails (35, 35') whereby one (35) is arranged opposite the blade plate (5) and the other (35') is arranged behind the blade plate (5), when viewed in the direction of rotation, such that it forms an angle of approximately 45° with said blade plate. Said blade plate (5) is inserted into a groove (33) which is formed in the peripheral surface of the tool and forms an insertion angle alpha with an imaginary diametrical line (D1) of the tool. The blade plate (5) comprises, respectively, a cutting surface (49) which is associated with a blade (9, 9') and a free surface (55) which cuts itself and the intersection lines thereof form the cut (9). The free surface (55) forms a free angle ß with an imaginary plane (E) which is perpendicular to the central plane (M) of the blade plate and which cuts the blade. An adjusting device (29), which is used to adjust the projection of the blade plate (5) over the peripheral surface of the tool (1), is provided. Said tool is characterised in that the insertion angle alpha and the free angle ß are adapted to one another such that the equation alpha - ß = approx. 1°, and also an effective free angle of approximately 1 ° is established.

Description

Tool for fine machining of bore surfaces

description

The invention relates to a tool for fine machining of bore surfaces according to the preamble of claim 1 and a knife plate for fine machining of bore surfaces according to the preamble of claim 15.

Tools and blades of the type discussed here are known (DE 37 33 637 A1). The known tools discussed here are reamers with the aid of which fine chips are removed from the surface of bores in workpieces. The tools have a blade plate, which is embedded in the base body of the tool and fixed there, also one of the blade plate - as seen in the direction of rotation - trailing first guide bar and one of the blade plate opposite guide bar. The knife plate, also referred to as a perforated plate, is fastened to the main body of the tool by means of a clamping screw. In order to set the blade plate radially, so to be able to pretend the supernatant of the blade plate on the peripheral surface of the tool, the clamping screw engages in a designated as a pivot lever intermediate piece, which is anchored to the main body of the tool. This design takes up a relatively large amount of space, so that tools with small diameters can not be realized or only with the use of high costs. The knife plate has a chip removal surface and an open surface, the cutting line forms the geometrically defined cutting edge. The side surfaces of the blade plate extend at an angle of 90 ° to the front, also referred to as a knife breast. The knife plate is used to realize the clearance angle, compared to a diameter serlinie pivoted inserted into the main body of the tool. Because of the space required for swivel lever, the swivel angle is approximately ≤ 20 °. This causes a little positive or even a negative rake angle. A knife plate of the known type can have four cutting edges, two on the front and two on the back. It has been found that in many cases the cutting edges are subject to a relatively high initial wear, so that the tool must be readjusted after a first use, especially with small tolerances. In this case, the radial projection of the blade plate and thus its cutting edge is adjusted over the peripheral surface of the main body of the tool.

In another known tool with a knife plate (Journal WB, Issue 6, 2004, Carl Hanser Verlag) a knife plate is used, which is also inserted at an angle to an imaginary diameter line in the main body of the tool. Again, the side surface extends to the front of the blade plate at an angle of about 90 °, which is why this is also inclined relative to a diameter line at an angle in the main body of the tool. The angle of inclination here can be about 10 °, because the blade plate is held by a clamping claw. In the end face of the tool, a central recess is provided, in which a common centering tip can engage, which is used in adjusting the radial projection of the blade plate relative to the main body of the tool, also in the production of the main body of the tool. It turns out that with small diameters, a central projection on the front side must be provided in order to realize this central recess. In the known tool is provided that for the Cutting necessary clearance angle not ground into the cutting edge, but is realized by the corresponding pivoted mounting position of the cutting edge in the body. The blade plate has eight blades, four on the front and four on the back. It is seen square in plan view square and therefore requires, seen in the radial direction, a relatively large space. In the case of this tool as well, it has been found that in many cases the cutting edge is subject to a relatively high initial wear, so that readjustment is required after the first use of the tool.

Finally, it is known (DE 44 05 749 A1) to provide two free surface regions in the case of a knife plate of a reamer, one of which adjoins the sheath directly and has a clearance angle which is substantially smaller than that of the first free surface region. The realization of two open space areas requires a high production accuracy, which is relatively expensive.

The object of the invention is therefore to provide a simple, inexpensive way a tool that has no high initial wear.

To solve this problem, a tool is proposed which comprises the features mentioned in claim 1. It is characterized by the fact that the installation angle α, ie the angle which encloses the blade plate with an imaginary diameter line, and the clearance angle, ie the angle which the free surface to an imaginary plane which is perpendicular to a center line of the blade plate, are tunable to each other so that sets an effective clearance angle of about 1 °. The clearance angle is thus on the one hand large enough to prevent jamming of the tool in the bore to be machined, but on the other hand so small that the tool can be supported on the free surface of the blade plate, whereby excessive wear of the geometrical edge of a blade plate at the first use of the tool ges is avoided.

Further embodiments of the tool will become apparent from the dependent claims.

The object of the invention is also to provide a blade plate for fine machining of bore surfaces, which does not have the disadvantages mentioned above.

To solve this problem, a blade plate is proposed, which has the features mentioned in claim 15. It is characterized by the fact that the clearance angle ß of the guide surface is tunable to the mounting position (installation angle α) of the blade plate in the main body of a tool that sets an effective clearance angle of about 1 °, so the equation α - ß = ca 1 ° is satisfied.

Embodiments of the blade plate will be apparent from the corresponding dependent claims.

The invention will be explained in more detail below with reference to the drawing. Show it:

Figure 1 is a side view of a tool;

Figure 2 is an end view of the tool of Figure 1;

Figure 3 is an enlarged detail view of Figure 2; Figure 4 is a perspective view of a first embodiment of a knife plate;

Figure 5 is a perspective view of a second embodiment of a knife plate;

Figure 6 is a perspective view of a third embodiment of a blade plate and

Figure 7 is a perspective view of a fourth embodiment of a knife plate.

From the illustration according to FIG. 1, the front part of a tool 1 can be seen, in the base body 3 of which a blade plate 5 is held, which is held by a clamping claw 7. The tool 1 described below is a cutting reamer comprising only a single knife plate 5 with a geometrically defined cutting edge 9, which is indicated in FIG. 1 only. In the knife breast 11, ie in the viewer facing the front of the blade plate 5, a clamping groove 13 is introduced, in which engages a clamping lip 15 of the clamping claw 7. The clamping groove 13 is inclined relative to the central axis of the knife plate 5, not shown here and thus with respect to the axis of rotation 17 of the tool 1 and closes with this an acute angle, which opens according to Figure 1 to the left. As a result, during clamping of the clamping claw 7 by means of a clamping claw 7 penetrating, and engaging in the main body 3 of the tool 1 clamping screw 19 Spannkraftkompo- components acting on the one hand perpendicular to the axis of rotation 17 and on the other hand parallel from right to left. This leads to the fact that the knife plate 5 on the one hand in the direction of the axis of rotation 17 festge- is clamped and on the other hand pressed in the axial direction against a provided to the left of the blade plate 5 stop 21, which is formed for example by the end of an introduced into the base 3 groove for receiving the blade plate 5 or by a introduced into the base 3 pin.

The main body 3 of the tool 1 is chamfered following the end face 23 of the tool 1, so that a chip space 25 is formed which receives the chips removed by the cutting edge 9.

From Figure 1 it can be seen that the blade plate 5, in particular the cutting edge 9, projects beyond the peripheral surface 27 of the tool 1. The supernatant is adjustable by means of an adjusting device 29, which here comprises a screwed into the main body 3 of the tool 1 screw 31 which acts on the cutting edge 9 opposite side surface of the blade plate 5, either directly or via an actuating wedge. The perspective view of Figure 1 reveals that the adjusting screw 31 is disposed closer to the end face 23 of the tool 1 as the clamping screw 19. Furthermore, it can be seen that the adjustment device 29 only a single set screw 31 includes. If this is further screwed into the main body 3 of the tool 1, the cutting edge 9 is displaced radially outwards, specifically in the area facing the end face 23 of the tool 1. The opposite end of the blade plate 5 is preferably located directly on the bottom of a knife plate receiving groove 33 in the base body 3. Trained as a cutting reamer tool 1 has a concealed in the illustration of Figure 1 first guide bar, which lags at a rotation of the tool 1 about the axis of rotation of the blade plate 5, also a second guide rail 35, the knife plate 5 opposite in a groove 37 is inserted in the basic body 3 of the tool 1.

Accordingly, the first guide bar is inserted into a groove in the main body 3 of the tool 1 and fixed there in a suitable manner, for example, soldered.

FIG. 2 shows an end view of the tool 1 shown in FIG. 1, that is to say a plan view of the end face 23. The same parts are provided with the same reference numerals, so that reference is made to the description of FIG.

Clearly recognizable here is the inserted into the groove 33 blade plate 5, also used in the groove 37 second guide rail 35. Visible here is the first guide rail 35 ', which is embedded in the associated groove 37' in the base body 3 of the tool 1.

The outside of the guide rails 35, 35 'is arched, preferably circular arc-shaped, wherein the radius of curvature of the outer surfaces of the guide rails 35 and 35' is preferably slightly smaller than that of the machined by the tool 1 bore. As a result, the tool 1 can be supported on the bore surface, whereby a lubricating film given between the outer surface of the guide rails 35, 35 'and the bore surface is optimally maintained. FIG. 2 shows that a coolant / lubricant channel 39 is guided through the main body 3, which opens in the area of the knife breast 11 and in particular in the vicinity of the active cutting edge 9, so that a coolant / lubricant is applied directly to the machining area. can be introduced range when the tool 1 is used.

FIG. 2 shows the clamping claw 7 and the clamping lip 15 resting on the knife breast 11, and also the recess 41 in the clamping claw 7 for receiving the clamping screw 19.

In the end face 23, a central recess 43 is introduced, in which a conventional centering can engage, on the one hand in the adjustment of the radial projection of the cutting edge 9 of the blade plate 5 relative to the main body 3 of the tool 1, on the other hand, in the production of the main body 3 of the tool 1 is used.

It is clear from FIG. 2 that the groove 33 serving to receive the knife plate 5 extends only so far into the base body 3 of the tool 5 that the end face 23 in the region of the central recess 43 is not damaged by the groove 33. The groove 33 thus terminates at a radial distance from the axis of rotation 17 and to the central recess 43 of the tool 1.

FIG. 2 also shows that the groove 33 is practically rectangular in cross-section. The groove bottom 45 thus extends perpendicular to the side flanks of the groove 33, of which the right serves as abutment surface 47 for the blade plate 5. This is, as the plan view of Figure 2 shows, seen in cross section also rectangular in shape, so that between the outside of the measuring Serplatte 5 and this receiving groove 33 do not form any free spaces into which chips produced during the machining of a workpiece could penetrate. This leads to a high reliability of the tool 1. Moreover, a good conditioning of the knife plate 5 is provided on the groove bottom 45. Finally, a simple and cost-effective production of the groove 33 results.

The upper left corner of the blade plate 5 is quasi broken off and shown in partial section. It can be seen that in the knife edge 11 following the cutting edge 9, a depression is introduced, which is formed inclined relative to the knife edge 11 and the rake face 49 forms, on which run away from the cutting edge 9 chips and in reach the chip space 25. The rake surface 49 includes with the knife edge 11 an angle γ, which is referred to as rake angle. FIG. 2 clearly shows that the rake surface 49 extends to the right starting from the cutting edge 9 located on a diameter line D1. It is thus realized here a positive rake angle, which may be about 12 °, which is desirable in particular in the processing of soft materials, such as aluminum. At a smaller angle, or even at a negative angle, where the rake face is to the left of the diameter line D1, chip upsetting, which leads to poor surface quality, would result, especially when machining soft materials.

The knife plate 5 itself is inserted into the base body 3 of the tool 1 in such a way that its knife edge 11 encloses an imaginary diameter line D1 with an angle α, which is referred to as the installation angle. Figure 3 shows the pivot axis 17 facing away from the extreme end of the blade plate 5 greatly enlarged and insofar schematized, as the rake surface 49 is not reproduced.

The groove bottom 45 facing away from the longitudinal side 51 includes with the knife edge 11 and the parallel extending back of the blade plate 5 at an angle of 90 °. It is thus also perpendicular to an imaginary center plane M of the blade plate 5. The longitudinal side 51 does not reach up to the cutting edge 9 of the blade plate 5, but it falls directly in front of the cutting edge 9 at an angle ß from here 9 ° to the cutting edge 9 from , The opposite of the median plane M corner of the blade plate 5 is formed symmetrically. Again, the longitudinal side 51 falls directly in front of the back 53 of the blade plate at an angle ß from 9 ° here.

The sloping region of the longitudinal side 51 forms the free surface 55 of the cutting edge 9 or the free surface 55 'of an opposite cutting edge 9'.

The cutting edge 9 is ultimately formed by the line of intersection of the free surface 55 with the associated rake surface 49, not visible in FIG. 3, which is arranged inclined with respect to the knife edge 11 by the rake angle γ.

In Figure 3, an imaginary plane E is drawn, which, as the longitudinal side 51 of the blade plate 5 is perpendicular to the median plane M of the blade plate 5 and the cutting edge 9 and -sofern existing- the symmetrical to the midplane M cutting edge 9 'intersects. The free surface 55 and the free surface 55 'close with the imaginary plane E an angle ß, which is naturally just as large as the angle which the free surfaces 55, 55 'form with the longitudinal side 51 of the knife plate 5 lying parallel to the plane E.

FIG. 3 also indicates the circle of flight F on which the active cutting edge 9 of a knife plate 5 moves when the tool moves counterclockwise in the plan view according to FIG. 2 and accordingly in FIG. 3, ie in the direction of the arrow 57 ,

FIG. 3 makes it clear that the longitudinal side 51 does not touch the circle F when the blade plate 5 is used, because it falls in the direction of the rear side 53 in a last region. It is of no consequence whether in the area of the rear side 53 a cutting edge 9 ', which is symmetrical to the median plane M, is provided. The last sloping region of the longitudinal side 51, which forms an open space 55 ', is at a distance from the circle of flight, which may be, for example, about 0.1 mm. In any case, it is ensured that the blade plate 5 does not touch a bore wall in the area of the rear side 53, because it is arranged at a distance from the circle of flight F.

FIG. 4 shows a perspective view of a first exemplary embodiment of a knife plate 5. Identical parts are provided with the same reference numerals, so that reference is made to the preceding descriptions in order to avoid repetition.

The blade plate 5 has a total of four cutting edges, namely two on the front side, also referred to as the knife edge 11, and two on the rear side 53. On the knife breast 11, the corner 57/1 lying on the top right is provided with a main cutting edge 9h and a minor cutting edge 9n. FIG. 4 shows that the free surface 55, which merges into the longitudinal side 51 of the knife plate 5, adjoins the rake surface 49 directly. If the plant shown in FIG. tool moved from left to right, ie in the feed direction, the knife plate 5 shown in Figure 4 is displaced accordingly in the direction of the double arrow 59 and thereby subjected together with the tool 1 of a rotary motion. The main cutting edge 9h is arranged sloping in the feed direction, ie in the direction of the double arrow 59. The secondary cutting edge 9n drops in the opposite direction, which, however, is not recognizable in view of the low angle of inclination in FIG. It runs parallel to the central axis 63 of the knife plate 5. The angle of inclination of the secondary cutting edge 9n is realized by corresponding adjustment of the position of the knife plate 5 in the main body of the tool 1. The configuration of a cutting edge 9 with a main cutting edge 9h and a minor cutting edge 9n is known in principle, so that it will not be discussed in detail here.

The cutting edge 9 is associated with a clamping surface 49 explained with reference to FIG. 2, which is introduced into the knife breast 11 and which, starting from the cutting edge 9, drops in the direction of the median plane M of the knife plate 5 and merges into the knife breast 11 via a chip breaker 61 ,

The knife plate 5 has on its front side, ie on the side of the knife edge 11, in the region of its lower left corner 57/2 on a configuration which is designed point-symmetrical to that, as explained with reference to the corner 57/1.

Clearly visible is the clamping groove 13 which is placed in the knife edge 11 and arranged inclined so that it drops on the knife breast 11 from top left to bottom right. From the illustration according to FIG. 4, it becomes clear that the clamping groove 13 is closed at its ends and has two clamping surfaces extending in the longitudinal direction of the clamping groove 13 and inclined relative to their central axis and falling away from the center plane M of the knife plate 5. The design of a clamping groove 13 of the type discussed here is basically known, so that will not be discussed in detail here.

The back 53 of the blade plate 5 is formed identically as the knife breast 11. So it has, as well as the knife edge 11, two diagonally opposite corners 57/3 and 57/4 on which a cutting edge with a corresponding rake face and a chip breaker is provided , The embodiment corresponds in each case to that explained with reference to the corner 57/1, so that it will not be discussed further here.

Overall, it is clear that the blade plate 5 according to the embodiment of Figure 4 has four blades, of which two of the knife breast 11 and two of the back 53 are assigned, being provided on each side of the cutting at diagonally opposite corners of the blade plate 5 and identical ,

If the blade plate 5 is inserted into a tool 1, then the tool 1, seen in the feed direction, rotates clockwise. In this case, when the blade plate is inserted according to Figure 4 in a tool 1 according to Figure 1, the cutting edge 9 of the corner 57/1 engage with the bore wall of a workpiece, so that the cutting edge 9 is referred to as an active cutting edge. In such a feed movement and direction of rotation, the cutting edge 9 of the corner 57/1 defined as right-cutting. In the embodiment according to FIG. 4, all the cutting edges of the knife breast 11 and the rear face 53 are right-hand cutting.

If the cutting edge 9 is worn at the corner 57/1, the knife plate 4 can be rotated by 180 ° about an axis which is perpendicular to the knife breast 11. Thus, the cutting edge 9 'of the link 57/2 engages with the bore wall of a workpiece to be machined. If the cutting edges are worn at the corners 57/1 and 57/2, the blade plate 5 is rotated about an axis of rotation 63 so that the rear side 53 comes to rest at the position of the knife breast 11 shown in FIG. In this position, the blade plate 5 is then installed in the tool 1 according to Figure 1, so that the blade lying at the corner 57/4 now comes into engagement with the bore wall of the workpiece to be machined. If the cutting edge located at the corner 57/4 is worn, the blade plate 5 is again rotated by 180 ° about an axis, which is then perpendicular to the back 53, so that thereby the blade 9 located at the corner 57/3 the active Cutting edge of the blade plate 5 forms.

The knife plate 5 can thus be arranged by appropriate rotational movements so that the cutting of the corners 57/1, 57/2, 57/3 and 57/4 can be used.

It is clear from the illustrations according to FIGS. 3 and 4 that the width of the free surface 55 is very small compared with the total width of the knife plate 5. The width b of the flank 55 may be in the range of about 0.06 mm to about 0.15 mm. It is preferably <0.1 mm. Incidentally, it is clear that the length L of the blade plate 5 is at least twice as large as its width B. Also, it can be seen that the width B is at least twice as large as the thickness D. By these ratios of L, B and D. It should be made clear that the blade plate 5 seen in plan view is elongated long and rectangular and relatively narrow. This embodiment of the blade plate 5 causes the receiving groove 33 in the base body of a tool 1, seen in the radial direction, not very deep. The groove bottom 45 is thus at a distance from the axis of rotation 17 of the tool 1, so that in the end face 23 of the tool readily a central recess 43 can be introduced. Thus, even with small diameters of the tool 1, no extension provided on the end face 23 is required, as is the case with known tools. As a result, the tool 1 builds very small. Moreover, its production is relatively inexpensive.

In the exemplary embodiment illustrated in FIG. 4, the rake face 49 provided at the corners 57/1 to 57/4 is part of a depression 64 introduced into the knife breast 11 or the back 53, which is approximately 60% of the longitudinal side 51 and approximately 50 % of the front side 65 of the blade plate 5 extends.

Figure 5 shows an embodiment of a knife plate, which is basically identical, as explained in Figure 4. The only difference is that the depression 64 extends over the entire length L and width B of the knife plate 5 relative to the front side 11 and rear side 53, respectively. Since the exemplary embodiment according to FIG. 5 does not differ further from the exemplary embodiment illustrated in FIG. 4 except for the configuration of the depression 64, reference is made to the explanations regarding FIG. 4 with regard to the remaining features of the exemplary embodiment according to FIG. For better understanding, the reference numerals provided in FIG. 4 are adopted in FIG.

FIG. 6 shows a further exemplary embodiment of a knife plate 5. The exemplary embodiment illustrated here corresponds to the basic construction of the knife plate according to FIG. 5. Thus, cutting edges are provided at the diagonally opposite corners 57/1 and 57/2 of the front edge designated as the knife breast 11; Corners 57/3 and 57/4 of the rear side 53. According to the definition given above, the cutting edges at the corners 57/1 to 57/4 are right-cutting cutting edges, which on the respectively addressed sides of the knife plate 5 are diagonally opposite each other are opposite.

At the remaining corners 67/1 and 67/2 on the knife edge 11 and 67/3 and 67/4 on the side of the back 53 of the blade plate 5 diagonally opposite cutting are provided, which formed according to the other cutting but left-cutting due to their arrangement are. Overall, the blade plate 5 according to FIG. 6 has eight blades at the eight corners 57/1 to 57/4 and 67/1 to 67/4.

The clamping groove 13 is arranged parallel to the axis of rotation 63 in this embodiment. Since the blade plate is designed according to Figure 6 as the blade plates in Figures 4 and 5, reference is made to the explanations to these figures.

Finally, FIG. 7 shows a fourth exemplary embodiment of a knife plate 5. This corresponds essentially to the exemplary embodiment illustrated in FIG. 4, so that reference is made to the description of this figure. Identical parts are provided with the same reference numerals, so that a renewed description of the apparent with reference to FIG 4 parts is omitted.

The exemplary embodiment according to FIG. 7 thus has two diagonally opposite, right-cutting cutters 9 and 9 'at the corners 57/1 and 57/2 of the front side of the knife plate designated as the knife breast 11. Accordingly, at the corners 57/3 and 57/4 of the rear side 53 of the blade plate 5 identically designed cutting edges are provided, which on the rear side 57 again face each other diagonally.

The difference from the embodiment shown in Figure 4 is that the edges are assigned to the edges 57/1 to 57/4 on the opposite side of the blade plate 5 bevels 69, wherein the bevel 69/1 of the corner 57/1 and the bevel 69/3 are assigned to the corner 57/3. Accordingly, the corner 57/2 not shown here bevel 69/2 and the corner 57/4 a bevel 69/4 assigned.

The function of the bevels 69/1 to 69/4 becomes clear from the explanations to FIG. 3: It explained that the active cutting edge 9 is arranged on the circle F in each case. The longitudinal side 51 drops on the opposite side of the blade 9, so that here a distance to the circle F is given. This avoids that the active cutting edge 9 opposite side of the blade plate 5 engages with the machined bore wall into engagement and damage.

For the function of the tool 1 and the blade plate 5, note the following:

The tool 1 is designed as a single-cutting reamer and has a blade plate 5 with at least four cutting edges, of which two are arranged diagonally opposite each other on one of the two sides, the knife breast 11 and the back 53.

The given in this way four cutting a blade plate 5 are designed, for example, right-hand cutting. From Figure 6 it can be seen that the blade plate 5 may also have eight cutting edges, namely four on the knife breast 11 and four on the back 53. The diagonally opposite cutting edges are cutting in the same direction. The cutting edges lying at the corners 57/1 to 57/4 are right-hand cutting and the cutting edges lying at the corners 67/1 to 67/4 are left-cutting.

On their longitudinal sides 51, which run perpendicular to the knife breast 11 or to the back 53 and thus to an imaginary center plane M, the knife plates 5 extend obliquely downwards into the end regions lying to the knife breast 11 or to the back 53, respectively, to the front or rear side. which can be designed as free surfaces 55, 55 'and assigned to the respective cutting edges. However, it is also possible to assign an open surface 55 to each cutting edge and to position it on the cutting edge. opposite side of the blade plate 5 to provide a chamfer 69.

In both cases, the active cutting edge opposite flattening of the longitudinal side 51 is provided so that only the active cutting edge lies on the circle F and thus engages with a bore surface, while the opposite edge of the blade plate 5 the circle F and thus the bore wall not touched and damaged.

The free surface 55 is very narrow interpret and preferably about <0.1 mm wide and serves as a support surface, so that the first use of the tool 1 and a blade plate 5, the wear of the active blade 9 is reduced to a minimum.

The knife plate 5 is, seen in plan view, narrow and rectangular, so much longer than wide. Moreover, it is designed to be relatively thin and thus takes up little space in the base body 3 of the tool 1. This leaves on the end face 23 of the tool room for a central recess 43, which is important for the adjustment and production of the tool 1.

The knife plate 5 is relative to an imaginary diagonal D1, as shown in Figure 2, relatively slightly inclined in such a way that an installation angle α results, which is so matched to the inclination angle ß of the guide surface 55 that in the built

Condition of the blade plate 5 in the tool 1 an effective clearance angle ß of about 1 ° results. The following applies: α - ß = approx. 1 °. The free surface 55 thus falls against one at the point of contact of the cutting edge 9 with the Circle of F applied tangent against the direction of rotation of the tool seen from about 1 °.

The installation angle can be in the range of 7 ° to 10 °. By appropriate choice of the clearance angle ß results in each case the desired effective clearance angle of about 1 °.

Due to the flat inclination, ie due to the acute angle γ, the rake angle γ can be, for example, 12 °. He can therefore be chosen positively, so that even soft materials can be processed without chip jam.

In order to ensure a secure hold of the blade plate 5 in this receiving groove 33 in the main body 3 of the tool 1, the clamping groove 13 with respect to an imaginary center line of the blade plate 5, as shown in Figures 1, 4, 5 and 7, inclined , wherein the inclination angle is about 10 ° in order to optimally divide the tension forces applied by the clamping lip 15 of the clamping claw 7 into clamping forces which urge the knife plate 5 against the groove base 45 and on the other hand press against a stop 21.

From Figure 1 it can be seen that the radial adjustment of the blade plate 5 serving adjusting device 29 preferably comprises only a single screw 31, wherein the end face 23 of the tool 1 facing the end of the blade plate rests on the adjusting screw 31 and a parking wedge and the opposite end of the Knife plate, which faces the stop 21, directly on the groove bottom 45. This makes it possible to design the tool 1 very compact and in particular to realize small tool diameter. As a result of the fact that the knife plate 5 is rectangular in its front view or in cross-section, it can be inserted into a corresponding rectangular groove 33, the production of which is relatively simple and thus cost-effective. By adapting the contour of the knife plate 5 and groove 33 free spaces are prevented, in which chips can penetrate during the machining of workpieces.

The designated also as a knife breast 11 front of the blade plate 5, as well as their identically formed back 53 have a completely closed contour, especially when the rake surface 49 and the chip breaker 61 is made by non-cutting process, ie by sintering, lasers or the like , This results in a particularly good investment of the blade plate 5 on the contact surface 47 of the groove 33 in the main body 3 of the tool first

Since even with the compact structure of the tool 1, the coolant / lubricant can be conveyed via the coolant / lubricant channel 39 directly into the region of the active cutting edge 9, it is possible to realize a so-called minimum quantity lubrication during the machining of workpieces In the air a lubricant is added only drop by drop.

Overall, it is found that the tool 1 is relatively simple, because it can be dispensed with any pivoting lever, as used in the attachment of blade plates in conventional tools. Nevertheless, due to the elastic deformation of the clamping lip 15 of the clamping claw 7, a radial adjustability of the blade plate 5 is possible. The knife plate 5 is before

21 the adjustment process by means of the clamping claw 7 firmly clamped and only then adjusted, while radially pushed so far outward until the desired machining diameter of the tool 1 results. This increases the originally applied clamping force of the clamping claw. Due to the obliquely introduced clamping groove, the blade plate 5 is pressed against both the axial stop 21 and against the groove bottom 45 and thus securely held in the base body 3 of the tool 1.

Since the clamping groove 13 weakens the blade plate 5 only insignificantly, this can be designed to be relatively thin, so that overall the dimensions of the tool 1 can be reduced. This also tools 1 can be realized with a small outer diameter, without resulting in an unacceptable weakening of the base body 3 due to the construction of the tool.

Claims

claims

1. A tool for fine machining of bore surfaces with a blade plate (5) having at least four geometrically defined cutting edges, two of which are arranged on the front and two on the back side of the blade plate and with at least two guide rails, one of which is opposite the blade plate and one of the blade plate - seen in the direction of rotation - lags by about 45 °, the blade plate is inserted into an inserted into the peripheral surface of the tool groove and with an imaginary diameter line of the tool includes an installation angle α and wherein the blade plate each associated with a cutting edge Span surface and an open space, which intersect and the cutting line forms the cutting edge, wherein the free surface with a cutting edge, imaginary plane which is perpendicular to a median plane of the blade plate includes a clearance angle ß, and wherein an adjustment device for adjusting the supernatant d he blade plate is provided over the peripheral surface of the tool, characterized in that the installation angle α and the clearance angle ß are so matched to each other that the equation α - ß = about 1 °, that is, an effective clearance angle of about 1 ° established.

2. Tool according to claim 1, characterized in that the width b of the free surface (55) is about 6 / 100mm to about 15 / 100mm, preferably about <0.1mm.

3. Tool according to claim 1 or 2, characterized in that the installation angle α is about 7 ° to about 12 °, preferably about 10 °.

4. Tool according to one of the preceding claims, character- ized in that the blade plate (5) - seen in plan view - is rectangular.

5. Tool according to one of the preceding claims, characterized in that the length L of the blade plate (5) is at least twice as large as the width B.

6. Tool according to one of the preceding claims, characterized in that the thickness D of the blade plate (5) is smaller than the width B.

7. Tool according to one of the preceding claims, characterized in that the width B of the blade plate (5) is at least twice as large as the thickness D.

8. Tool according to one of the preceding claims, characterized in that the width B of the knife plate (5) is smaller than the radius of the tool (1).

9. Tool according to one of the preceding claims, character- ized in that the knife plate (5) has a preferably closed clamping groove (13).

10. Tool according to one of the preceding claims, characterized in that the clamping groove (13) relative to the central axis of the knife plate (5) is inclined.

11. Tool according to claim 10, characterized in that the inclination angle of the clamping groove (13) is approximately 10 °.

12. Tool according to one of the preceding claims, characterized in that a clamping claw (7) with a Spannr lip (15) is provided.

13. Tool according to one of the preceding claims, characterized in that the knife plate (5) is rectangular in cross-section.

14. Tool according to one of the preceding claims, character- ized in that an adjusting device (29) with a

Adjusting element is provided which acts on the end face (23) of the, tool (1) facing the end of the blade plate (5).

15. Knife plate for fine machining of bore surfaces by means of a tool, in particular a tool according to one of claims 1 to 14, with two geometrically defined cutting on the front and two geometrically defined cutting on the back, each with a cutting edge associated rake surfaces and open spaces , which intersect and whose cutting line form the cutting edges, wherein the free surface encloses a clearance angle β with an imaginary plane intersecting the associated cutting edge, which plane is perpendicular to a median plane of the knife plate, characterized in that the relief angle β is applied to the Mounting position of the blade plate (5) in the tool, so on the installation angle α, tunable that the equation α - ß = about 1 ° applies, so that sets an effective clearance angle of about 1 °.

16. Knife plate according to claim 15, characterized in that the free surface (55) has a width b of about 0.6 mm to about 0.15 mm, preferably of about <0.1 mm.

17. Knife plate according to claim 15 or 16, characterized in that - as seen in plan view - is rectangular.

18. Knife plate according to one of claims 15 to 17, characterized in that the length L of the knife plate (5) is at least twice as large as the width B.

19. Knife plate according to one of claims 15 to 18, characterized in that the thickness D of the knife plate (5) is less than the width B.

20. Knife plate according to one of claims 15 to 19, characterized in that the width B of the knife plate (5) is at least twice as large as the thickness D.

21. Knife plate according to one of claims 15 to 20, characterized in that the width B of the knife plate (5) is smaller than the radius of the tool (1) into which the knife plate (5) can be inserted.

22. Knife plate according to one of claims 15 to 21, characterized in that it has a preferably closed clamping groove (13).

23. Knife plate according to claim 22, characterized in that the clamping groove (13) relative to the central axis of the knife plate (5) is inclined.

24. Knife plate according to claim 22, characterized in that the inclination angle of the clamping groove (13) is approximately 10 °.

25. Knife plate according to one of claims 15 to 24, characterized in that it is rectangular in cross-section.