WO2002045895A1

WO2002045895A1 - Method and device for producing undercuts on geartooth flanks

Info

Publication number: WO2002045895A1
Application number: PCT/EP2001/013357
Authority: WO
Inventors: Jörg Fred MAZAK; Hans Udo Heym
Original assignee: Wera Werk Hermann Werner Gmbh & Co
Priority date: 2000-12-08
Filing date: 2001-11-19
Publication date: 2002-06-13
Also published as: AU2002216046A1

Abstract

The invention relates to a method and device for profiling workpieces, in particular for the generation of undercuts (1), or similar, on geartooth flanks (2) of internally or externally toothed working gears (3). The above is achieved by machine cutting of the rotated workpiece (3), using a cutting edge tool, which is also rotated in a worktool axis, parallel to the workpiece axis, with a fixed speed relationship to the working gear, but with variable phase position, the cutting edge of which is displaced along an envelope curve corresponding to the profile form as a result of a combination of a variation in axial separation (A) and phase position (P), overlaid on the rotation. According to the invention, an improved device with regard to increased performance can be achieved, whereby the cutting edges work with an increasing axial separation for external toothed working gears and decreasing axial separation for internal toothed working gears and with a cutting direction opposed to the direction of displacement.

Description

00001 Method and device for generating background

00002 on tooth flanks 00003

00004

00005 The invention relates to a device and a method

00006 ren for creating deposits or the like

00007 tooth flanks of internal or external gear wheels

00008 by machining the rotary driven workshop

00009 of the by means of a likewise rotary driven cutting

00010 edge tool, which around a to the work wheel axis

00011 parallel tool axis in a fixed, but in the

00012 phase position variable speed ratio to the work wheel

00013 rotates, the cutting edge of which indicates that one of the rotating

00014 superimposed combination of variation of the axle

00015 state and variation of the phase position on one of the

00016 deposit form, corresponding envelope advanced

00017 will. 00018

From DE 42 00 418 Cl or EP 0 550 877 B1

00020 known methods or devices. In the process

00021 or the devices corresponds to the shape of the background

00022 the cutting section of the cutting

00023 th single tooth percussion knife. This is a cycloid.

00024 In practice, however, other deposit contours

00025 desired. DE 199 suggests a multi-tooth tool

00026 33 137 AI propose to design the teeth differently,

00027 so that the envelopes of the machining flight

00028 circular sections of the individual teeth to the desired

Add 00029 deposit contour. The one shown there

00030 method or with the device described there

However, 00031 is hardly a re-sharpening of the multi-tooth tool

00032 possible. 00033 00034 The invention is based, the generic

00035 according to the method or the generic device

00036 to improve performance. 00037

According to the invention it is provided that the cutting edge

00039 with increasing center distance with the feed

00040 opposite cutting direction works. The chip removal

00041 de trajectory section of the cutting edge performs this

00042 workpiece thus from the outside in. If the procedure

For example, 00043 for milling deposits

00044 toothed workpieces used, the cutting takes place

00045 pretty with every cut from the outside in. The machining

00046 tion itself takes place gradually from the inside to the inside

00047 outside. The tool can be designed as a single-tooth fly knife

Forms 00048. However, the tool is also provided

To train 00049 as a multi-tooth knife. In particular, it can

00050 Multi-tooth knives, left and right cutting edges

00051 den, so that one on both tooth flanks of teeth

00052 deposit can be profiled. With an interior

00053 toothed work wheel is initially clockwise

00054 rotating work wheel the left flank and then by rotating

00055 change of direction machined the right tooth flank. Becomes

00056 machined the left tooth flank, so run to

00057 Machining the right flank provided cutting edge

00058 th freely through the gaps of the factory wheel. According to the

00059 design according to the invention, the cutting edges are

00060 sharpenable. With the inventive method or

00061 device according to the invention can

00062 contours can be machined. 00063

According to a development of the invention,

00065 that the cutting edge with a very small angle

00066 emerges from the tooth flare. This angle is

00067 half an angle at which burrs form, so

00068 that minimal, tolerable burrs can form 00069 den. This can deburr the milled work wheel

00070 due to reworking in the area of the flank

00071 ben. At most in the area of protuberance ridges can

00072 arise, which may be removed by post-processing

Must be 00073. The feed is preferably continuous.

00074 both the distance variation and the

00075 phase position variation constantly changed, so that after

00076 a full revolution of the work wheel or after completion

00077 the closed cycloid chip by chip from the dental

00078 edge is removed, the cut in the direction

00079 of the tooth gap takes place, but the feed in opposite

00080 direction. The cycloid parameters are set so

00081 that the turning points of the cycloids outside the Spanish

00082 lifting flight section. For generation

00083 a deposit on a toothed tool

00084 first machined a tooth flank. This happens before

00085 pulls with a multi-tooth tool. For this, the additional

00086 toothed tool on an externally toothed work wheel

00087 reduction of the center distance and with an internally

00088 toothed work wheel by increasing the center distance

Delivered to the rotating workpiece. The

00090 phase position so that the cutting teeth touch

00091 freely engage in the tooth gaps of the workpiece.

00092 After the center distance is its minimum or maximum

00093 has been reached, a pure immersion

00094 supply, only the phase position being changed.

00095 If the center distance is fixed, the cutting step occurs

00096 flight circle section of the cutting edges to the desired depth

00097 into the workpiece. This can result in a burr

00098 hen. Only then is there a simultaneous enlargement

00099 reduction (external gear) or reduction (internal

00100 internal gear) of the distance dimension and change

00101 the phase position the gradual milling of the profile

00102 form or the deposit. The increment by

00103 the feed rate is specified is so 00104 selected that the emerging cutting edge essentially

00105 loosens the chip from the workpiece without burr formation.

00106 An almost freely selectable contour line is created

00107 drive. In a further development of the invention,

00108 see that the phase position by rotating the

00109 tool axis and the workpiece axis intersecting

00110 stand ropes in the room is varied. This can be done

00111 that either the workpiece axis or the

00112 Tool axis in one plane, the respective axis

00113 cuts at right angles, is relocatable. Then needs

00114 for changing the phase position the speed does not vary

00115 to be. Turn workpiece axis and tool axis

00116 continue uniformly. Feed and delivery take place

00117 simply by moving one of the two axles

00118 sen in said plane. 00119

00120 An embodiment of the invention is described with reference to

00121 added drawings explained. It shows: 00122

00123 Fig. 1 in a rough schematic representation of a tooth

00124 flank and a total of eleven flight circle sections

00125 a describing an involute trajectory

00126 cutting edge as a result of the invention

00127 feed, 00128

00129 FIG. 2 shows an illustration according to FIG. 1 before thawing

00130 chen, 00131

3 shows a representation according to FIG. 1 after the first

00133 chip removal, 00134

4 shows a representation according to FIG. 1 after the third

00136 chip removal, 00137 00138 FIG. 5 shows a representation according to FIG. 1 after the six00139th chip removal, 00140 00141 FIG. 6 shows a representation according to FIG. 1 after the eighth 00142 chip removal, 00143 00144 FIG. 7 shows the parameter sets axis distance / phase angle 00145 as a function of the tool radius, 00146 00147 FIG. 8 a gear-shaped cutting tool, 00148 00149 FIG. 9 a section along the line IX-IX in FIG. 8, 00150 00151, FIG. 10 a basic illustration of an inner wheel machining 00152, 00153 00154 FIG. 11 a tool of a second exemplary embodiment , 00156 00157 Fig. 12 is a plan view of a "tooth" forming two cutting edges 00158, 00159 00160 Fig. 13 is a section along the line XI-XI in Fig. 11 00161 and 00162 00163 Fig. 14, another embodiment of the inven tion which the phase position is varied by rotating the 00165 center distance in space. 00166 00167 The explanations of the exemplary embodiment relate 00168 to the use of the method for generating 00169 deposits on gear-shaped workpieces. The 00170 process can also be carried out on differently designed work pieces. 00172 00173 Elements of a device for performing the method 00174 show DE 42 00 418 Cl and EP 0 550 877 00175 Bl. The tool there is a rotary driven 00176 tooth percussion knife which rotates around a stationary axis 00177 , The workpiece can be an internal or external gearwheel. The factory wheel also rotates on a 00179 stationary axis. In the exemplary embodiment, both 00180 axes are parallel to one another. The two axes 00181 can also have an axis cross angle to each other. 00182 machining follows tooth mesh, which means that 00183 work wheel and tool axis rotate in a fixed speed ratio to each other. Relative to the be00185 work wheel, the single-tooth flyknife then writes a cycloid movement 00186. 00187 00188 According to the invention, the tool 00189 is advanced in that the center distance A between the Werk00190 wheel axis and the workpiece axis changes continuously. At the same time 00191, with this variation of the center distance, 00192 the phase position P is continuously changed. The change is made 00193 in such a way that the cutting circle sections, 00194 that is, those curve sections of the cycloids that carry chips out of 00195, run on an envelope curve 00196 that corresponds to the form of the deposit. The 00197 variation of the center distance and phase position follows accordingly 00198 according to a predetermined law of motion (see 00199 Fig. 7). 00200 00201 It is also important that the feed is in the opposite direction 00202 to the cutting direction. The first cut begins 00203 at tooth base 4 and the last cut ends in tooth ridge 00204 area 3, whereby the cutting direction always goes from ridge 3 00205 to the foot. 00207 Fig. 1 shows I - XI successive flight circles

00208 a cutting edge. Each flight circle shown there

00209 becomes closed after passing through a large number

00210 cycloid reached after the previous one. With the

00211 cutting edges 10, 11 become one from the tooth flanks 2

00212 gear 1 deposits 5 milled out. This

00213 follows in the direction of the by varying the

00214 center distance A and the variation of the phase position P

00215 defined direction of the feed V. The direction of the

00216 feed V depends on the parameters of the center distance

00217 speed of variation and speed of change

00218 from. The direction of the feed is therefore not

00219 stant, but changes in the course of processing. 00220

00221 FIG. 3 shows the flight circle section I of the cutting

00222 edge 10, 11 before immersion in the workpiece. The

00223 Delivery up to this position is done by

00224 the center distance, which in particular the milling

00225-shaped tools 9 with its cutting edges

00226 ends the teeth with the teeth of the workpiece 1 combs.

00227 In the position shown in Fig. 2 has the distance dimension

00228 from workpiece axis to tool axis for a

00229 working internally toothed gear at its maximum. By

00230 change of the phase position the flight circle of the cutting

00231 edge in the direction of the arrow E shown there

00232 relocated, so that the flight circle section cutting into

00233 can dip the tooth flank 2. 00234

00235 In FIG. 3 the effect of this is due to the thawing

00236 shown generated first step. From the

00237 Zabnflanke 2 was an arcuate section 6 out

00238 milled. The immersion depth corresponds to the target depth

00239 fe. 00240 00241 Furthermore, the distance between the axles 00242 and the phase position are now varied in such a way that the axle distance 00243 (with an internal gear) is continuously reduced. As a result, the flight circle section is shifted to 00245 an envelope curve which corresponds to the finished profile shape 00246. The flight circle is shifted in 00247 in a changing direction of arrow V. The 00248 cutting direction is opposite to this. 00249 00250 Fig. 4 shows the effect of the 00251 section labeled IV. With this cut, the cutting edge 00252 emerges at point 8 from the bottom of the 00253 cut previously made. The exchange angle is so small that 00254 no burr forms there. The UtT-Kehrp-inkt of the cyclo-00255 de is always outside the cutting flight section 00256 cut. The Uι .-- keh - ^ point can lie within the 00257 already profiled flank section 7. 00258 00259 The contour of the deposit is defined by the phase position 00260 to each center distance. The 00261 relationship in this regard between phase position and center distance is shown, for example, by the curve shown in FIG. 7 in 00262. 00263 The course of this curve defines the shape of the backing contour. 00265 00266 Fig. 7 shows two parameter sets center distance / phase 00267 angle each for different tool radii. The curve designated 00268 with A relates to a tool with a tool radius 00269 larger than the 00270 curve designated B. The tool radius changes because the 00271 tool is reground. As a result, 00272 the curves move to smaller center distances. The curves 00273 there are no straight lines because their course determines the profile contour 00274 of the deposit. 00275 00276 A tool designed as a multi-tooth knife is shown in 00277, FIG. 8. The knife has 00278 cutting edges arranged in a star shape with cutting edges 10 or 00279 11 of the same design The cutting flanks 12, 13 leading to the cutting edges 00282 10, 11 have a constant cross-sectional contour 00283 and run in a straight line, so that the cutting edges 10, 11 can be resharpened by removing material from the head flanks 14 00285. 00286 In the exemplary embodiment, left-hand cutting 00287 and right-hand cutting edges 10, 11 alternate with one another. 00288 It is also possible to arrange the left-cutting and 00289 right-cutting edges differently. 00290 00291 The rake angle can be freely selected depending on the material or the machining task. 00293 00294 In the case of an internally toothed work wheel which, for example, first rotates clockwise, the left tooth flank is first machined using the 00296 tool. 00297 After changing the work wheel, the right tooth flank is machined. The cutting edges that process the other 00299 tooth flank then run freely 00300 through the gaps in the teeth. In general, the 00301 ratio of the speed of the work wheel to the workpiece is chosen to be 00302 so that it is a real prime number quotient. For 00303 machining of work wheels with a block tooth it is 00304 to select an integer speed ratio 00305. The accessory tool then has the shape shown in 00306 in FIGS. 11 to 13, in which a pair of 00307 cutting edges is missing at point 00308 marked with 15. This position corresponds to the block tooth on the 00309 work wheel. 00310 00311 In the embodiment shown in FIG. 14

00312 is an internally toothed workpiece. The

00313 diameter of the tool is smaller than the radius

00314 of the factory wheel. The workpiece rotates in the

00315 play around the fixed axis of rotation 16. Spaced to

00316 stationary axis of rotation 16 lies in the drawing

00317 ne displaceable axis 17 of the tool 9. The axis 17th

00318 can be moved along the center distance 18

00319 den. This serves to vary the center distance. The

00320 axis 17 can also in a direction transverse to it

00321 to be relocated. By overlaying these two

00322 movements, the center distance 18 in

00323 Turn space. Such a rotation is due to the axis

00324 would be 17 'or the shifted center distance 18 "

00325 indicated. All feed movements can only

00326 by moving the tool axis 17 in the

00327 level are performed, the workpiece 1 and

00328 the tool 9 are continuously driven in rotation.

00329 The phase angle variation is so with this solution

00330 not due to a phase shift of the two

00331 gene achieved, but by varying the spatial

00332 Chen assignment of the two axes 16, 17. The motors,

00333 which drive the tool 9 or the workpiece 1,

00334 can run with this solution with a constant phase.

00335 This is advantageous because linear movements are significant

00336 are more precisely adjustable than dynamic phase changes

00337 gen. The more precisely the phase shift is set there

00338, the slower the axes can turn. In the

00339 of the plane shiftable axis 17 can for example

00340 can be assigned to a cross table. It is also

00341 possible that this axis 17 on an arch slot guide

00342 is guided, which ver around the center of the axis 16

00343 is running. 00344 00345 All disclosed features are (in themselves) inventive

00346 considerably. In the disclosure of the registration is hereby

00347 also the disclosure content of the associated / attached

00348 priority documents (copy of pre-registration) fully

00349 included in the content, also for the purpose of features

00350 of these documents in claims of this application

00351 to record. 00352

Claims

00353 claims 00354

00355 1. Method for profiling workpieces, in particular

00356 another for generating deposits (1) or the like

00357 teeth on tooth flanks (2) from inside or outside teeth

00358 work wheels (3), by machining the rotating

00359 driven workpiece (3) by means of a likewise rotating

00360 driven cutting edge tool, which by a

00361 tool axis parallel to the workpiece axis in one

00362 fixed, but in the phase position changeable speed

00363 Relationship to the work wheel, the cutting edge of which follows

00364 ge a combination of the rotary movement superimposed

00365 variation of the center distance (A) and variation of the phase

00366 senlage (P) on one of the profile shape

00367 envelope is advanced, characterized in that

00368 that the cutting edges in an externally toothed

00369 work wheel with enlarging or with an internally

00370 toothed gear wheel reducing center distance with

00371 feed works in opposite cutting direction. 00372

00373 2. The method according to claim 1 or in particular according thereto,

00374 characterized in that the cutting edge (10, 11)

00375 first by a pure phase change in the

00376 the workpiece is immersed and then the machining

00377 flight circle section on a profile corresponding

00378 envelope curve by variation of phase position and axis

00379 stood by the workpiece is working. 00380

00381 3. Method according to one or more of the preceding

00382 the claims or in particular according thereto, characterized

00383 distinguishes that the cutting tool at an angle

00384 the profile section (7) already machined,

00385 which is below a burr formation angle. 00386

00387 4. Method according to one or more of the preceding

00388 the claims or in particular according thereto

00389 due to a constant but not proportional axle

00390 Stand and phase position variation. 00391

00392 5. Method according to one or more of the preceding

00393 the claims or in particular according thereto, characterized

00394 records that the tool is a multi-edge tool

00395 (1), especially with straight-edged blades (10,11)

00396 is. 00397

00398 6. Method according to one or more of the preceding

00399 according to the claims or in particular according thereto,

00400 indicates that the front in the workpiece rotation direction

00401 tooth flank is processed. 00402

00403 7. Method according to one or more of the preceding

00404 the claims or in particular according thereto, characterized

00405 records that the speed ratio of the work wheel and

00406 Tool is an integer and the tool is a gap

00407 (15). 00408

00409 8. Method according to one or more of the preceding

00410 according to the claims or in particular according thereto,

00411 shows that the phase position is caused by a rotation of the

00412 the tool axis (17) and the workpiece axis (16)

00413 intersecting center distance (18) varies in rooms

00414 will. 00415

00416 9. Method according to one or more of the preceding

00417 the claims or in particular characterized thereby

00418 shows that with constant rotation of work

00419 tool axis (17) and workpiece axis (16) of the feed

00420 only by relocating one of the two

00421 axes (16, 17) in one plane.

00422 10. Tool for performing the method according to

00423 one or more of the preceding claims or

00424 especially afterwards, each with a large number

00425 left and right cutting, especially alternating

00426 arranged cutting edges (10, 11), characterized thereby

00427 records that according to the cutting edges (12, 13)

00428 a constant rake angle and a constant

00429 end cross-sectional contour is resharpenable. 00430

00431 11. Device for carrying out the method according to

00432 one or more of the preceding claims,

00433 is characterized by two synchronizable ones

00434 electronically driven rotary axes, whose

00435 stand is variable, characterized in that the

00436 phase position of the two rotary drives as a function of

00437 center distance is variable. 00438

00439 12. Device for performing the method according to

00440 one or more of the preceding claims,

00441 characterized in that at least either the factory

00442 tool axis (17) or the workpiece axis (18) in one

00443 direction essentially transverse to the center distance

00444 (18) is relocatable. 00445

00446 13. Device for performing the method according to

00447 one or more of the preceding claims,

00448 characterized in that the transverse to the center distance

00449 route (18) displaceable axis cross-slide in

00450 two directions perpendicular to each other linear

00451 is relocatable.