EP1799381A1

EP1799381A1 - Tool for machining tire profiles

Info

Publication number: EP1799381A1
Application number: EP05783441A
Authority: EP
Inventors: Alfred Heimann
Original assignee: Hegenscheidt MFD GmbH and Co KG
Current assignee: Hegenscheidt MFD GmbH and Co KG
Priority date: 2004-09-10
Filing date: 2005-08-25
Publication date: 2007-06-27
Also published as: DE102004044372B4; US20080202296A1; WO2006027114A1; DE102004044372A1; CN101043962A

Abstract

The invention relates to a tool comprising a cylindrical (22) or mushroom-shaped (9) cutting plate made of a hard material such as hard metal or cutting ceramics, which is fastened to a cutter support (8, 16, 23), which is mounted in a tool support that can be displaced in the X and Z direction of a lathe. The cutter support (8, 16, 23) is arranged at an acute angle (a) to the tangent (13, 20, 33) on the circle of a cut in a plane (4) perpendicularly passing through a workpiece profile (1) and can rotate and be driven about its longitudinal axis (12, 19, 31). The inventive tool makes it possible to cause, in all working areas of the reprofiling of wheels of wheelsets of railway vehicles, the breaking of the cuttings and has the simple most possible design that is operationally reliable. To this end, the invention provides that the tool for turning the tire profile (1) of wheels (5) of a wheelset of railway vehicles is provided on a wheelset lathe with different cutting depths during a single reprofiling step.

Description

Tool for editing wheel tire profiles

The invention relates to a tool for machining the wheel tire profile of wheels of a wheel set of railway vehicles on a Radsatzdrehmaschine with a cylindrical or mushroom-shaped cutting plate of a hard material, such. Carbide or cutting ceramic, which is mounted on a cutter support, which in turn is mounted in a tool support, which is displaceable in the x and z-direction of the wheel lathe.

Without special measures on the tools, very long chips are produced during the turning of steel, which can severely hinder the working process and whose removal is complicated and difficult. For this reason, so-called chip breakers and bumps are mounted by the tool manufacturers on the cutting plates of turning tools, which should in principle compress the chip so far that its deformability is exceeded, so that it breaks. It is customary for the manufacturers to state in which areas of the feed and the depth of cut these chip deflectors take effect. In this context, from DE 23 39 588 Al an indexable insert has become known, are formed at each of the two used for machining end faces two diagonally opposite corners as clamping surfaces for the same workspace and two adjacent corners as clamping surfaces with complementary work area , Another solution is to form and steer the chip in such a way that it bumps against an obstacle (eg workpiece or tool) and is deflected in such a way that it breaks at the root. In this way, short filament chips are produced.

In order to protect a cutting insert in heavy cuts, it receives a chamfer that protects the cutting edge from breakage. If such a plate is now operated with a small chip cross-section, the chips no longer break because the chip no longer comes into contact with the chip-forming elements. Therefore, an insert can only cause chips to break in a limited operating range.

In manufacturing, it often helps in the way that you use different inserts.

When reprofiling wheels of wheelsets of railway vehicles, the aim is to produce the wheel tire profile such that it touches the wear profile at one point, usually in the flank, but also in the running surface. Since you want to stay in a cut for reasons of accuracy and time savings, causing the chip breakage is not possible in every workspace, especially not at low cutting depths. As a result, the automation of the machining process is greatly impaired and requires additional effort for facilities for breaking and conveying the chips. For example, EP 0 346 505 discloses a method for <. Generation of shavings during the turning of workpieces, in particular wheels of wheelsets of railway vehicles, known. The amount of feed speed of the rotary tool is changed for short times during the rotation of the wheelset. Within a short time, the tool cutting edge along the wheel tire profile is retracted each time to the forward feed line in the original direction and to the previous amount of the feed speed which is intended for further processing.

However, the known method produces an increased roughness in a certain area. It can not be arbitrarily short chips generated because the support speeds are limited.

From DE-PS 558 905 a tool with automatically rotating, cantilevered, circular cutting body is known. The cutting tool works with great accuracy because the lifted chip is discharged through the interior of the mushroom-shaped, hollow and rotating cutter body. The problem of inducing chip breakage is not addressed.

From DE 29 37 513 Al, the use of a high-speed rotating cutting tool is known. In the process, a film of oil or lubricating fluid is developed in the cutting zone and in the tool-chip interface. The combination of low friction and reduced shear forces makes it possible to produce lamellar chips of almost any dimension. But nothing is said about it, like Chip breaking at different cutting depths in a single cutting section can be brought about.

DE 33 05 700 C2 has the goal of producing high surface quality, as it is carried out in the cutting finishing of calender paper rolls, for the processing of metals and their alloys and non-metallic items on lathes. The known method is very similar to the rotary milling and describes the relative positions of the tool and workpiece and their relative rotational movements to each other. Again, it is not spoken of breaking the chips removed.

The tool which is furthermore known from US Pat. No. 5,014,581 is intended for use on lathes for machining high-alloyed and difficult-to-turn metals at high cutting speeds. In conventional cutting materials wear is to be reduced and the service life increased. This is achieved with the aid of a cutting tool, which is either driven by the workpiece itself or from outside and has an annular disk as a cutting edge. This results in a cutting process in which constantly a fresh cutting edge is introduced into the cutting zone in addition to the usual feed. The rotary driven tool provides a wide range of possibilities, some of which result in lower cutting forces, increased shear angle, increased tool life and better finish. However, this document does not point to the generation of chip breakage.

Hence the task for the invention to propose a tool that in all work areas of Reprofiling of wheels of wheelsets of railway vehicles is able to bring about the breaking of shavings. This should be possible with both large and small chip cross sections. The tool should be configured as simple and reliable as possible in its construction.

According to the invention a tool for rotating the wheel tire profile of wheels of a wheel set of railway vehicles is proposed on a Radsatzdrehmaschine in which the blade carrier at an acute angle (α) to the tangent to the circle of a section in a plane arranged perpendicularly through the Radreifenprofil and rotatable about its longitudinal axis and is drivable. This tool produces chip breaking even at low cutting depths.

As cutting tools, cylindrical or mushroom-shaped cutting inserts are made of a hard material, such as e.g. Carbide or cutting ceramic, used, which are known per se. Due to the rotation of such circular cutting plates, which are intended for heavy machining in Radsatzzerspanung, chip breaking can also be brought about in areas where otherwise no chip breaking occurs, thus primarily at low depths.

The rotation of the cutting plate is done by motor with adjustable speed and variable direction of rotation. Due to the rotation of the cutting plate, the chip running over the cutting plate is additionally deformed. By choosing the direction of rotation and rotation speed, the chip can be steered against a fixed obstacle. This For example, the cutting tool, which is given a special shape, can itself be the workpiece, for example the flank of the wheel set. The rotational movement need not be uniform, but it is possible after a certain time, for example, 100 ms, as soon as the chip has a certain length (eg unwound 100 mm), bring about the chip breakage with a short rotational movement.

The cutting plate is rotated by the CNC control of the wheel lathe. It is provided to make both the direction of rotation and the rotational speed of the cutting plate according to the respective processing situation variable. Likewise, according to the cutting pressure at large cutting depths and feeds, the rotational movement of the cutting plate can be stopped. This is also for the mechanical design of the drive advantageous because it has to muster only low torques.

The tool is intended for the machining of wheelsets for railway vehicles with a wheel diameter between 850 mm and 1250 mm for full tracks and 600 mm for tram vehicles. When machining large workpieces, such as wheelsets for full tracks, the bearing of the rotating tool is directly and is limited to very small space. By arranging the tool with a negative angle of attack, the available space can be increased even more. In wheelsets, it makes sense to make a further misalignment of the axis of rotation of the tool in the direction of the axis of rotation of the wheelset also with regard to the collision with the flange of the wheel. But such misalignment can also be done in the tool itself be taken into account. For example, it is possible to combine a stable cutting edge with a tool bearing that is closer to the tool and sufficiently rigid. For wheelsets must be made in addition to a further misalignment of the tool in the direction of the axis of rotation of the wheelset. When programming the movements of the tool for generating the wheel tire profile, it should of course be noted that the point of contact of the tool with the workpiece changes in relation to a conventional tool.

Furthermore, when using rotating inserts, it should be noted that a concentricity error of the insert in its bearing and a form error of the insert lead to a wavy surface. This makes it necessary to carry out the storage of the cutting plate and its shape shape within small Fertigungstoieranzen.

Finally, it should be noted that with the tool in a small space high forces must be absorbed and that the tool heats up during processing. The bearing of the tool must therefore be designed so that it remains free of play and accurate rotation despite heating.

The invention will be described in more detail below with reference to several exemplary embodiments.

1 shows a first embodiment of a cutting tool, in a greatly simplified and largely schematic representation; FIG. 2 shows a second embodiment of a cutting tool, FIG.

- Fig. 3 shows the drive of a tool in section and

- Fig. 4 shows the section through a tire profile in natural size.

The tire profile 1 of FIG. 4 consists of a tread portion 2 and a flange portion 3. A section which is placed approximately in the middle of the tread portion 2 perpendicular through the Radreifenprofil 1, referred to as measuring circle level 4. In addition, FIG. 4 also shows the machining directions x, y and z of the wheel lathe. The y direction extends perpendicular to the drawing plane of FIG. 4.

A wheel 5 of a wheel set (not shown) is rotatably received in a wheel lathe (not shown) about the longitudinal axis z of the wheel set in the direction 6. FIG. 1 shows a section through the wheel 5 approximately at the level of the measuring circle plane 4 of FIG. 4. During the rotation, the wheel tire profile 1 is machined by a tool 7. The tool 7 consists of a blade carrier 8 and a mushroom-shaped cutting plate 9 made of hard metal. The blade carrier 8 and the cutting plate 9 are rotatably connected to each other and additionally have projections and recesses 10, over which they are interlocked. The tool 7 is rotatably mounted in a tool support (not shown) of the lathe in the direction of the double arrow 11. The

The axis of rotation 12 is arranged at an acute angle α to the tangent 13 to the measuring circle plane 4 of the wheel 5. The "mushroom-shaped cutting plate 9 is designed in such a way that it has outwardly inclined flanks 14 and has a recess 15 in its center.

Here, a cutter support 16 carries a cylindrical cutting plate 17. Also in this case, a toothing 18 is provided between the cutter support 16 and the cylindrical cutting plate 17. The cutter support 16 with the cylindrical cutting plate 17 is rotatably mounted about its axis of rotation 19 in the support (not shown) of a Radsatzdrehmaschine. The sharp one

Angle α between the axis of rotation 19 and the Radtangente 20 is significantly smaller in the case of Fig. 2 than in FIG. 1. This arrangement requires a bottle neck shape of the cutter support 16 so that it can be brought as close as possible to the wheel 5.

In FIG. 3, a tool 21 is provided, which has a cylindrical cutting plate 22. The cutting plate 22 is soldered on a bolt 23, which consists of high-strength steel. The finishing of the pin 23 takes place in the interest of concentricity of the cutting plate 22 only after the soldering of the cutting plate 22 on the bolt 23. The bolt 23 is mounted in a flachkegeligen bearing shell 24. This has the task to transfer the cutting forces coming from the main section of the cutting and the advancing and passive forces into the basic holder 25, without the cylindrical part of the pin 23 being loaded too heavily. The bearing shell 24 is a wearing part and is exchanged with the cylindrical cutting plate 22. The bolt 23 has at the lower end 26 a splined 2> 7, which engages in a hardened bevel gear 28. At the point 29, the bevel gear 28 is roller-mounted independently of the pin 23. A second bevel gear 30 transmits the torque generated upon rotation of the cylindrical insert 22 about the rotation axis 31 to a controllable servo motor (not shown) via a high-ratio planetary gear (not shown). Interposed is a bolt 32, which carries the second bevel gear 30 that meshes with the bevel gear 28.

The base holder 25 is slidably mounted in the wheelset lathe in the x, y and z directions. The axis of rotation 31 of the cylindrical cutting plate 22 is inclined to the Radtangente 33 at the angle α.

Bez-ugs sign list

1 wheel tire profile

2 tread part

3 wheel flange part

4 measuring circuit level

5 wheel

6 direction of rotation

7 tool

8 cutter carrier

9 mushroom-shaped insert

10 protrusions and depressions

11 double arrow

12 axis of rotation

13 tangent

14 flank

15 deepening

16 cutter carrier

17 cylindrical insert

18 toothing

19 axis of rotation

20 bicycle dente

21 tool

22 cylindrical cutting plate

23 bolts

24 bearing shell

25 basic holder

26 lower end

27 VielkeilZerzahnung

28 hardened bevel gear

29 Storage

30 second bevel gear

31 rotation axis Bolt wheeled duck

Claims

PATENT APPLICATIONS

1. Tool with a cylindrical (22) or mushroom-shaped

(9) Cutting plate of a hard material such as cemented carbide or cutting ceramic, which is mounted on a cutter support (8, 16, 23) which is mounted in a tool support which is displaceable in the X and Z direction of a lathe, wherein the blade carrier (8, 16, 23) under a point

Angle (α) to the tangent (13, 20, 33) to the circle of a section in a plane (4) arranged perpendicularly through a workpiece profile (1) and is rotatable and drivable about its longitudinal axis (12, 19, 31), characterized in that the tool for rotating the wheel tire profile (1) of wheels (5) of a wheel set of railway vehicles is provided on a wheelset lathe at different cutting depths during a single reprofiling cut.

2. A tool according to claim 1, wherein a cut in the measuring circle plane (4) of the wheel tire profile (1) of the wheel

(5) lies.

3. Tool according to claim 1 or 2, d a d u r c h e c e n e s in that the direction of rotation

(11) of the cutter carrier (8, 16, 23) is reversible.

4.-Tool according to one of claims 1 to 3, d a d u r c h e c e n e c i n e s in that the rotational speed of the cutter carrier (8, 16, 23) is variable between 0 and n revolutions per minute.

5. Tool according to one of claims 1 to 4, d a d u r c h e c e n e c e in that the blade carrier (8, 16, 23) at an angle (ß) to the axis of rotation (z-direction) of the wheelset is arranged.

6. Tool according to claim 1 and 5, d a d u r c h e c e n e c e s e s that the acute angle

(α) is between 5 ° and 10 ° and the angle (β) is also between 5 ° and 10 °.