Method for producing an undercut with an oblique undercut edge

Abstract

The invention relates to a method and a device for producing undercuts (10) on tooth flanks (3) of a gearwheel (1), wherein the undercuts (10) have undercut surfaces that adjoin adjacent sections (16) of a tooth flank (3) by way of undercut edges (13, 14). According to the invention, spindle motors for driving a workpiece spindle and a tool spindle are driven in such a way that the undercut edges (13, 14) are inclined at an angle (α) with respect to a plane of rotation (D1, D2) about an axis (9) of the workpiece (1) and in particular in the same direction in which an edge (8) of a top surface (6) is inclined at an angle (β) with respect to a plane of rotation (D3).

Description

Description Method for producing a deposit with a slanted deposit edge field of technology

[0001] The invention relates to a method for producing backings on a gear with teeth arranged around an axis, each tooth flank having tooth flanks, wherein at least some of the tooth flanks each have a backing with at least a first backing surface extending offset relative to a tooth flank extension surface, which adjoins the tooth flank at a backing edge, wherein a toothed workpiece is rotaryally driven by a workpiece spindle, wherein a cutting edge tool having at least one cutting edge is rotaryally driven by a tool spindle synchronously with the workpiece spindle, wherein a cutting edge movement of the cutting edge is generated by a feed with a radial directional component in the axial distance direction of the workpiece spindle and the tool spindle and a phase shift between the rotation of the tool spindle and the workpiece spindle.which, by removing material section by section, creates the backing in at least one of the tooth flanks of the workpiece.

[0002] The invention further relates to a device for carrying out such a method. State of the art

[0003] DE 3240 165 A1 describes a method for manufacturing chamfers on the end faces of teeth of a gear. Such chamfers, which are also described in DE 1 048 762 B, serve to facilitate shifting in manual transmissions when two toothed elements of a transmission The teeth of a sliding sleeve are brought into tooth engagement, for example, when a sliding sleeve is to mesh with a gear. To maintain this engagement, the gear teeth have recesses. These recesses are localized depressions in the tooth flank into which sections of the teeth of a sliding sleeve can engage to maintain the gear's movement. The sliding sleeve has tooth flanks that are complementary to those of the gear teeth, and power is transmitted through these teeth. The contact surfaces of the tooth flanks should be as large as possible to optimize power transmission.

[0004] A method for producing deposits is described, for example, in DE 10 2015 104 242 A1. In this method, the axes of the workpiece and the tool run parallel to each other. Both axes are operated synchronously and, in particular, are each driven by electric motors that are synchronized via a control system. The feed has a radial component, relative to each of the axes of rotation. More generally, this directional component of the feed is directed in the axis spacing direction.

[0005] The specified contour line of the backing is maintained by changing the phase relationship of the two rotational movements during the change in the axis distance. A corresponding method is described in DE 101 16 259 B4.

[0006] If a cutting edge tool used in the production of the backings has a cutting edge running parallel to the axis of rotation of the tool axis, then, in such a superimposed feed movement, a backing with a backing surface is produced that is the bottom surface of a recess in the tooth flank, which is parallel to the tooth flank surface. can run. The edge of this backing surface runs in a plane of rotation around the workpiece axis of rotation, which is also the axis of rotation of the gear being machined.

[0007] If a gear manufactured in this way has the chamfers described at the beginning, in which the edges of the roof surfaces are usually not in the plane of rotation of the gear, a flank surface is created between the edge of the backing and the so-called switching edge (transition edge of the roof surface into the tooth flank) which has two boundary edges that do not run parallel to each other, so that this flank surface is trapezoidal.

[0008] The prior art described above discloses methods in which a cutting-edge tool is used in which the cutting edge runs parallel to the direction of extension of the workpiece's teeth. The workpiece spindle and the tool spindle run parallel to each other.

[0009] German patent DE 10 2014 108438 A1 describes a method for incorporating backings in which the backing flanks are produced by skiving. In skiving, the tool spindle axis and the workpiece spindle axis are at an axial angle to each other, so that a relative rotation of the two spindles results in a skiving motion. With a feed component in the tooth extension direction, the skiving tool can move axially through the workpiece. If a differential or tangential feed component is superimposed on this essentially axial movement, the backing flanks can be produced.

[0010] The starting point of the invention is a toothing system with teeth arranged around an axis, each having tooth flanks, wherein at least some of the tooth flanks each have a backing with at least one first backing surface extending offset from a tooth flank extension surface, which adjoins the tooth flank at a backing edge, and a method for manufacturing such backings, wherein a toothed workpiece is rotaryally driven by a workpiece spindle, wherein a cutting edge tool having at least one cutting edge is rotaryally driven by a tool spindle synchronously with the workpiece spindle, wherein a cutting edge movement of the cutting edge is generated by a feed with a radial directional component in the axial distance direction of tool spindle and workpiece spindle and a phase shift between the rotation of the tool spindle and the workpiece spindle, which in each section removes material and creates a backing in at least one of the tooth flanks of the workpiece. Summary of the invention

[0011] The invention is based on the objective of providing a method by which the course of the backing edge can be influenced in order to optimize, in particular, the shape of flank surfaces adjacent to the backing with regard to their load-bearing properties.

[0012] The problem is solved by the invention specified in the claims, which relates to a method for producing backings and a device for carrying out the method. This makes it possible to produce backings whose backing edge is inclined to a plane of rotation of the gear teeth that is perpendicular to the axis.

[0013] First and foremost, it is proposed that the feed rate be given an additional directional component that runs perpendicular to the axis spacing direction. This additional directional component can be implemented in axis- be directed towards the gear and extend along the direction of the tooth flank extension.

[0014] DE 44 10 743 A1 describes a method for producing backings, wherein the bottom of the depression forming the backing does not form a single surface, but consists of several sub-surfaces. Such a backing can, for example, have two backing surfaces that adjoin each other at a vertex. In cross-section, the two backing surfaces can, for example, form a V-shaped line, with each backing surface transitioning into the tooth flank by forming a backing edge. In the prior art, the two backing edges, as well as the backing vertex located between the backing edges, each lie in a plane of rotation.The invention also includes a method for producing such backings, consisting of backing surfaces inclined to the flank surface, whose backing edges have a pre-adjustable angle to the plane of rotation, in order to allow for a free design of a flank section to the end face of the gear tooth, even with such backings. The method described above can then be modified such that the phase shift used to produce generic backings is modified in such a way that a transition edge of two cutting edge sections of the cutting edge tool is advanced along a curved line, for example, a turning radius, relative to the tooth flank, along which the backing apex is to run. Similarly, a backing surface can also be produced whose surface sections are radii and which has a vertex line formed by a radius.The cutting edge can be rounded for this purpose, with the rounding having a vertex that corresponds to the greatest distance of the cutting edge from its axis of rotation. In other embodiments of the... According to the invention, the cutting edge can also have several cutting edge sections, in particular straight-running sections.

[0015] The feeds in the three directions (axial direction, axial distance direction, and azimuthal direction) are superimposed such that portions of the backing are cut section by section, i.e., in successive individual cuts. The apex of the cutting edge is guided along a line relative to the tooth flank on which the apex line of the backing is to extend. The two backing surfaces can be of different sizes. A larger backing surface can be inclined at a first angle to the tooth flank. The second, significantly smaller backing surface can be inclined at a second angle to the tooth flank. The apex line is preferably inclined away from the plane of rotation towards the smaller backing surface, for example, by a base point of the apex line. The sections of the larger backing surface, cut section by section into the tooth flank, connect to each other seamlessly.The apex of the cutting edge thus migrates with each cut—if it begins at the tooth root—by a certain amount away from the plane of rotation passing through the root point, with the cutting edge that cuts the larger backing surface performing the subsequent cut following the already cut surface. However, it is also possible to begin the successive cuts at the tooth head, in which case the position of the apex of the cutting edge, during the successive cuts, approaches a plane of rotation passing through the root point of the undercut's apex line. Here, too, it is intended that the individual cuts follow at least the larger backing surface. Brief description of the drawings

[0016] The invention will now be explained in more detail using exemplary embodiments. The figures shown are: Fig. 1 shows an externally toothed gear 1 with teeth 2, Fig. 2 a side view of the number wheel 1 according to Figure 1, Fig. 3 an internally toothed gear 1 with teeth 2, Fig. 4 shows section IV in Figure 1 in a perspective view, Fig. 5 shows a section approximately along the lines VV in Figure 1 or 3, Fig. 6 shows a top view of a tooth head 4 of a tooth 2 approximately in the direction of arrow VI in Figure 1, Figure 3 or Figure 5, Fig. 7 shows a representation according to Figure 5 of a second embodiment, Fig. 8 is a top view of a tooth head 4 of a tooth 2 in the direction of arrow VIII in Figure 7, Fig. 9 is a representation according to Figure 5 of a third embodiment, Fig. 10 shows a top view of a tooth head 4 of a tooth 2 in the direction of the arrow X in Figure 9, Fig. 11 shows a sectional view through a tool rotation axis Al and a workpiece rotation axis A2 of a tool head 24 engaged in a toothing of a workpiece 1. Fig. 12 shows the engagement position according to Figure 11, but along the section line XII-XII in Figure 11, Fig. 13 enlarges the engagement of the cutting edge tool 22 shown in Figure 11 when producing a backing 10, Fig. 14 is a representation according to Figures 6, 8 or 10 to illustrate the course of backing edges 13, 14 and a vertex line 15, Fig. 15 shows the sequence of several successive contour cuts of a cutting edge, each of which cuts a backing surface 11 into a tooth flank 3 of a tooth 4 section by section. Fig. 16 shows an end-face view of a cutting edge tool 22 having two cutting edges 23, Fig. 17 shows the view according to arrow XVII in Figure 16 of the cutting edge tool 22, Fig. 18 schematically shows a machine tool for carrying out the process and Fig. 19 shows the section along line XIX-XIX in Figure 18. Description of the embodiments

[0017] Figures 1 to 4 show the prior art described in an earlier application of the applicant (DE 3240 165 A1). Figure 1 shows an externally toothed gear 1 with teeth 2, with only one tooth shown; Figure 2 shows the side view of the gear 1; Figure 3 shows an internally toothed gear 1 with teeth 2; and Figure 4 shows, in perspective, the chamfers of the end faces of the teeth 3 described in that application. Using a method as described therein, or a method as described in DE 1048 762, roof surfaces 6 are produced by machining. These surfaces may be rounded (DE 1048 762) or meet at a ridge line 7 (DE 3240 165 A1). In both cases, the roof surfaces abut the tooth flank 3 of the tooth 2, forming a boundary edge 8.This edge 8 does not typically lie in a plane of rotation with respect to an axis 9 of the workpiece 1, but rather has an angle of inclination to such a plane of rotation. Figure 2 shows this inclined course of the edge 8.

[0018] The course of the edge 8 depends on the shape of the cutting edge of the roof edge tool and on the cutting circle of the roof edge tool. Figures 5 and 7 show embodiments in which the angle of inclination β (relative to a plane of rotation D3) from the tooth root 5 either increases towards the face of the tooth (Figure 5) or decreases towards the face of the tooth (Figure 7).

[0019] Gear teeth designed in this way for manual transmissions are described in older applications, for example in the The methods described in DE 100 02 188 Al or DE 101 16259 B4 incorporate the deposits. This is done using a deposit tool, such as the one shown in Figures 11 to 13 of DE 100 02 188 Al. are extracted. A workpiece spindle 20 drives a chuck in which a workpiece 1, for example a pre-toothed gear, is clamped. In the exemplary embodiment, this is an internally toothed gear 1 with teeth 2 into which backings 10 are to be milled. For this purpose, a tool rotation axis Al runs parallel to, but at a distance from, a workpiece rotation axis A2.

[0020] Cutting edge tools 22 project radially from a tool spindle 21, each forming at least one cutting edge 23. The cutting edges 22 preferably extend radially. The cutting edges 22 are used to machine the backings 10, shown particularly in Figures 6, 8, 10, and 14, into the tooth flanks 3 of the teeth. For this purpose, the tool spindle 21 is driven in a rotary motion synchronized with the workpiece spindle 20, so that the cutting edge 23 moves along a path that machines a backing surface 11 into the tooth flank 3. This backing surface is the bottom surface of a recess formed in the tooth flank 3. The path runs from the tooth tip of the tooth to be machined to the tooth root. The tool rotation axis A1 and the workpiece rotation axis A2 can be parallel to each other.

[0021] During machining, the tool, i.e., the tool head 24, is moved in a feed direction VI with respect to the workpiece 1. Here, the feed direction VI is a radial feed with respect to the two parallel axes Al and A2.

[0022] Figure 15 shows an illustration from another earlier application, namely DE 101 16 259 B4, in which the course of the backing surface 11 is specifically adjusted by a phase shift between the rotation of the tool rotation axis Al and the workpiece rotation axis A2. The phase shift- The sliding motion is superimposed on the feed VI and thus corresponds to an azimuthal feed V2. The cutting edge trajectories, designated by the Roman numerals I to X, show how the backing 10 is produced section by section, by removing only a partial section of the tooth flank 3 with each passage of the cutting edge 23 through the tooth gap 17. Such a contouring action allows the backing surface 11 to be given an individual contour. The sections of the backing surface 11 produced in the individual, successive cuts merge into one another, so that in each individual cut only a partial surface is cut, which gradually approaches either the tooth root or the tooth tip.

[0023] However, the previously described method can only produce such backings 10 where the backing edges 13, 14, at which the backing surface 11 transitions into a flank surface 3, 16, run in a plane of rotation with respect to the axis A2 of the workpiece 1. The backing edges 13, 14 or a vertex line 15 separating two inclined backing surfaces 11, 12 would then not run parallel to the edge edges 8 of the roof surface 6.

[0024] According to the invention, the previously described prior art method is further developed in that a further feed component V3 is superimposed on the feed VI, V2, which is directed parallel to the tool rotation axis Al or workpiece rotation axis A2. The feed rate in the feed component V3, relative to the rate in the direction of the radial feed VI, is adjusted such that, section by section in the movement sequence shown in Figure 15, edge edges 13, 14 of the backing 10 are generated, which have an inclination angle α to the plane of rotation. possess a D2, Dl. Here too, the individual sub-areas are manufactured one after the other.

[0025] With the previously described method, namely the superimposition of the feed motion by a further feed component V3 in the axial direction, it is thus possible to generate inclination angles α which have the same tendency with respect to their inclination direction as the inclination angles β of the edge edges 8. It is therefore even possible to produce the backing edges 13, 14 parallel to the edge edge 8. However, the application of the method is not only suitable for providing chamfered teeth 2 with backings. With the method it is also possible to produce backings with inclined backing edges 13, 14, in which the edge edges 8 run in the plane of rotation or in which no edge edges 8 are present at all. With the method according to the invention, it is also possible to work two backings side by side into a tooth flank, in which the backing edges 13, 14 of the different backings are inclined in opposite directions.

[0026] Figure 5 of another earlier application, namely DE 44 10 743 Al, shows a deposit with deposit edges running in the plane of rotation and additionally a deposit vertex extending in the plane of rotation.

[0027] Figures 9, 10, and 14 show a backing with backing surfaces that, as in the previously mentioned prior art, are inclined to the tooth flank. Unlike the previously described embodiment, the backing surfaces do not run parallel to the tooth flank 3. Here, the backing surfaces consist of two sub-surfaces 11 and 12 that are inclined relative to each other, such that the two inclined backing surfaces- chen 11, 12 adjoin each other, forming a vertex line 15. During In the state of the art, this vertex line 15 runs in a plane of rotation Dl.

[0028] By a further modification of the method known from the prior art (DE 101 16 259 B4), such backings 10 with backing edges 13, 14 or a vertex line 15 can also be produced, in which the backing edges 13, 14 run at an angle α to the plane of rotation D1, D2. Here, the azimuthal feed component V2, i.e., the phase shift of the rotary motion of the tool rotation axis Al to the workpiece rotation axis A2, must be modified such that a vertex 27, at which two cutting edge sections 25, 26 of a cutting edge 23 adjoin each other, runs on a curved line with respect to the contour of the tooth flank 3.In the machining process shown in Figure 15, where only one section of a backing 10 is produced at each tool pass, the vertex 27 follows a predetermined line, which can largely be a section of a helical path and which can run in a conical surface inclined at an angle α to a plane of rotation D1, D2. Here, the feed is carried out in the three feed directions such that the cutting edges of the cutting tooth, which cuts a larger backing surface 11, each produce a section of the backing surface 11 following the contours of the surface, with each cut producing a section of the vertex line 15 that is offset from the section produced in the previous cut both axially and azimuthally.

[0029] Figures 16 and 17 show a tool for carrying out the method in the form of a cutting edge tool 22, wherein a cutting tooth 2 has cutting edges 23 pointing away from each other, each of which has two cutting edge sections 25 and 26 meeting at a vertex 27. The cutting- Edge segments 25, 26 can run in straight lines. In the area of ​​the vertices 27, the two diverging cutting edges 23 have their greatest distance apart.

[0030] Figures 18 and 19 schematically show the structure of a machine tool with a control unit 30 for controlling a spindle motor 31 for driving a workpiece spindle 20 and a spindle motor 32 for driving a tool spindle 21. The control unit 30 is programmed in such a way that the previously described method for generating inclined backings 10 can be carried out.

[0031] All features of a method and a device as described in DE 101 15259 B4 or DE 190 02188 Al can be incorporated into a method or device according to the invention, so that the content of these two documents is fully included in the disclosure content of this patent application.

[0032] The foregoing statements serve to explain the inventions covered by the application as a whole, which each independently further develop the prior art at least through the following combinations of features, whereby two, several or all of these combinations of features may also be combined, namely:

[0033] A method characterized in that with an additional directional component of the feed V3 transverse to the axis spacing direction the backing edge 13, 14 is generated, which is inclined by an angle a to a plane of rotation D1, D2 of the gearing perpendicular to the axis 9.

[0034] A method characterized in that the phase shift V2 has a first component to which a second component is superimposed, with which a vertex 27 of at least two cutting edge sections 25, 26 having or a rounded cutting edge 23 sectionally generates a vertex line 15 between two backing surfaces 11, 12 on a track curved in space, which runs parallel to the backing edge 13, 14.

[0035] A device characterized in that the control unit 30 is configured to carry out a method according to claim 1 or 2.

[0036] All disclosed features are essential to the invention (individually, but also in combination with one another). The disclosure of this application hereby incorporates in full the disclosure content of the associated / attached priority documents (copy of the earlier application), also for the purpose of including features of these documents in the claims of the present application. The dependent claims, even without the features of a referenced claim, characterize independent inventive developments of the prior art, in particular for the purpose of filing divisional applications based on these claims. The invention specified in each claim may additionally include one or more of the features described above, in particular those identified by reference numerals and / or listed in the reference numeral list.The invention also relates to design forms in which individual features mentioned in the preceding description are not realized, in particular insofar as they are recognizably unnecessary for the respective purpose or can be replaced by other technically equivalent means. List of reference symbols 1 gear / workpiece 30 control unit 2 tooth 31 spindle motor, workpiece spindle 3 tooth flank del 4 tooth head 32 spindle motor, tool spindle 5 Tooth base del 6 Roof area 33 Positioning drive 7 First line 8 Edge 9-axis aluminum tool rotary axis 10 Backing A2 Workpiece rotary axis 11 Deposit area B Movement path 12 Backing area Dl Rotation plane 13 Backing edge D2 Rotation plane 14 Backing edge D3 Rotation plane 15 Vertex line V 1 radial feed 16 flank surface V2 phase shift 17 tooth gap bung / azimuthal advancement V3 axial feed 20 W workpiece spindle 21 W tool spindle a angle 22 Cutting edge tool ß angle 23 Cutting edge 24 Tool head 25 cutting edge section 26 Cutting edge section 27 Vertex

Claims

Claims 1. Method for producing backings on a gear tooth with teeth (2) arranged around an axis (9), each tooth flank (3), wherein at least some of the tooth flanks (3) each have a backing (10) with at least one first backing surface (11, 12) extending offset relative to a tooth flank extension surface, which adjoins the tooth flank (3, 16) at a backing edge (13, 14), wherein a toothed workpiece (1) is driven by a workpiece spindle (20) in a rotary motion, wherein a cutting edge tool (22) having at least one cutting edge (23) is driven by a tool spindle (21) in a rotary motion synchronized with the workpiece spindle (20),wherein a cutting edge movement (B) of the cutting edge (23) is generated by a feed (VI) with a radial directional component in the axial spacing direction of the workpiece spindle (20) and the tool spindle (21) and a phase shift (V2) between the rotation of the tool spindle (21) and the workpiece spindle (20), which sectionally removes material and creates the backing (10) in at least one of the tooth flanks (3) of the workpiece (1), characterized in that an additional directional component of the feed (V3) transverse to the axial spacing direction is used to create the backing edge (13, 14), which is inclined at an angle (a) to a plane of rotation (D1, D2) of the gear toothing perpendicular to the axis (9).

2. Method according to claim 1, characterized in that the phase shift (V2) has a first component to which a second component is superimposed, with which a vertex (27) of at least two a vertex line (15) between two backing surfaces (11, 12) that runs parallel to the backing edge (13, 14) is created section by section on a track curved in space by having cutting edge sections (25, 26) or a rounded cutting edge (23).

3. Method according to one of the preceding claims, characterized in that the tool rotation axis (Al) and the workpiece rotation axis (A2) run parallel to each other.

4. Method according to one of the preceding claims, characterized in that the cutting edge (23) runs parallel to the tool rotation axis (Al).

5. Device for producing deposits on a toothing, comprising a workpiece spindle (20) driven by a spindle motor (31) for driving a toothed work wheel (1) and a tool spindle (21) driven by a spindle motor (32) which rotates a cutting edge tool (22) with cutting edges (23), and a control (30) for controlling the spindle motors (31, 32), characterized in that the control device (30) is configured to carry out a method according to claims 1 to 4.

6. Method or device characterized by one or more of the characterizing features of one of the preceding claims.

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