DE102005042410B4 - Tool and method for producing or post-processing a thread, in particular an internal thread - Google Patents

Abstract

Tool, designed as a circular thread former, for producing or reworking a thread, in particular an internal thread, comprisinga) at least one carrier body (3) through which a tool axis (A) passes, b) at least one thread forming element (20), whichb1) as prefabricated and / or or separate part is formed andb2) is fastened to the carrier body (3) by means of fastening means (5, 15), so that the annular axis of the tool axis (A) orb4) is disk-shaped, whereby the tool axis (A) is formed by the thread forming element (20). runs und und d) each thread forming element (20) at least one radially to the tool axis (A) outwardly projecting thread forming profile (10) for non-cutting generating or reworking the thread by pressing the thread forming profile (10) into a workpiece surface upon rotation of the carrier body (3 ) with the thread forming element (s) (20) about the tool axis (A) and a simultaneous sch screw-shaped and / or spiral feed movement (VB, ZB) of the carrier body (3) with the thread forming element (s) (20) about a tool axis (A) parallel and spaced from the tool axis (A) central axis of rotation (M).

Description

The invention relates to a tool and a method, each for generating or post-processing a thread, in particular an internal thread.

For threading or threading machining both cutting and non-cutting methods and threading tools are known. Chip removal threading is based on material removal of the material of the workpiece in the area of the thread. Chipless threading is based on forming the workpiece and creating the thread in the workpiece by pressure. Gewindefurcher are working axially to their tool axis threading tools with a trained on a tool shank work area having a helical tool axis rotating the tool axis with which the thread is pressed into the workpiece, ie with a circumferentially spirally or helically encircling external thread or thread profile, which represents the counter-shape to the thread to be produced.

In general, a Gewindefurcher has an approximately polygonal cross-section, so that along the then deviated from an exact cylindrical helical external thread of the working area offset further outwardly projecting and generally rounded polygonal corner regions, which are also referred to as press studs or furrows or mold wedges are formed, which follow the thread pitch of the helical thread profile. By this measure, the contact surfaces and thus the clamping forces are reduced during the forming. In this case, at least three corners or corner areas are required for the polygon, since the Gewindefurcher must support the thread generation at the edge of the hole or the outer edge of the thread.

The outer diameter or the cross section of the working area of a thread rolling increases in a start-up or inlet region, which is the actual shaping area, from the front end of the tool to the rear, usually conical, and remains substantially the same in a subsequent calibration and / or guide region. As a result, the thread is gradually produced by the ever deeper penetrating into the workpiece trough teeth of the starting area and possibly even after-smoothed or calibrated by the constant in their indentation fangs of the calibration.

To create a thread in an already existing bore, the thread former is advanced with the work area with a linear feed motion axially of the tool axis, i. the longitudinal axis of the tool shaft, and introduced by rotation of the tool about this tool axis in the bore. In this case, the teeth or shaped wedges or pressing lugs of the thread are pressed against the thread groove in the surface of the workpiece or the bore. The material of the workpiece is thereby pressed away predominantly radially, ie perpendicular to the longitudinal axis of the bore. Part of the thus deformed material is solidified, another part is forced into the recesses or grooves between the die or teeth of the Gewindefurchers, whereby a thread is finally produced in the workpiece.

These known thread guides are also referred to below as axial thread formers and the corresponding method as axial thread forming. Known embodiments of such (axial) Gewindefurcher can also be found in DE 101 36 293 A1 . DE 199 58 827 A1 , or even in DE 39 34 621 C2 ,

The DE 101 36 293 A1 discloses an axial thread former with a steel shank having at one end a clamping section and at the other end a shaped profile section (working area), wherein the shaped profile section is formed as a separate polygonal profile element made of a hard material having an inlet taper outside and at least two full channels having. The profile element is by means of a centric screw with a central screw and an axial threaded bore on the shaft or by means of a central threaded pin on the shaft and a thread in the profile element or a lock nut or by means of a solder joint and / or by a positive connection by means of radial cross-shaped projections and recesses Non-rotatably attached to the shaft.

DE 39 34 621 C2 describes an axial thread furrow having a shaping region with a polygonal cross section and with a thread profile corresponding to the thread to be produced on the outer circumference. Only in the area of the cross-section corners (tangs) of the shaping area are cylindrical strips of particularly hard and wear-resistant material such as sintered cemented carbide or cubic crystalline boron nitride (CBN) or polycrystalline diamond (PCD) soldered into corresponding axially extending grooves of the shaping area, which has a profile adapted to the thread profile on the outer circumference.

Out WO 02/094491 A1 For example, a non-cutting tapping tool and a chipless tapping method are known which can be cited on a circular form Based on the working principle. This in WO 02/094491 A1 disclosed thread forming tool is elongated and comprises a working area with one or more annular grooves separated by annular grooves (s). Each circumferential profile is formed in its center non-circular and has at least three surveys in the manner of a polygon as a pressing lug. In addition, axially extending grooves can be provided between the individual pressing lugs on the outer surface of the tool for supplying cooling liquid. As a material for the tool either a carbide or high speed steel is proposed.

This tool is now used in the method according to WO 02/094491 A1 introduced under rotation about its own axis in a bore with a larger diameter than the tool and performs a circular movement along the circumference of the bore and at the same time a feed movement into the bore and thereby formed without cutting the thread in the bore.

The thread is according to WO 02/094491 A1 So, in contrast to the axial thread furrows, not by means of a spiral, the thread pitch adapted active surface on the tool and an axial or linear feed movement of the tool formed relative to the workpiece, but by means of annular and thus stepless and at the same polygonal cross-sectional active surfaces on the tool on the one hand and a with a rotation of the tool about its own longitudinal axis combined helical movement of the tool, which results from a linear feed movement axially to the longitudinal axis of the tool and a circular movement of the longitudinal axis of the tool about a central axis of the bore.

This thread former is also referred to below as a circular thread former or, under extension of the hitherto customary nomenclature, as a circular thread binder and the associated method as circular thread forming or circular thread grooves.

Another circular thread former is now also from the DE 103 18 203 A1 known. This known circular thread former has at least one, preferably at least two profile projections on its forming head, which are formed polygonal over the circumference and with circumferentially changing radial extent. The profile projections thereby form over the circumference in each case a plurality of pressing lugs, which may be evenly or unevenly distributed over the circumference. The pressing lugs of adjacent profile projections may also be offset from one another in the circumferential direction, in particular along a helix. Furthermore, in one embodiment, a tool carrier made of a carrier material, for example hardened or soft steel, and at least one, preferably at least two cylindrical, conical or round toolbars, which are inserted into the carrier, made of a different material, such as hard metal, cermet, polycrystalline diamond, CBM or ceramic trained. The connection of the strips with the carrier can be done by soldering, screwing, clamping, gluing or welding. Furthermore, the forming head can be provided with a coating at least in the area of the pressing lugs for reducing friction and / or reducing wear, for example made of diamond, TiN, TiAlN or TiCN or a multilayer or lubricating layer, for example MoS ₂ . The depth of the grooves between adjacent profile projections may also vary circumferentially.

US 3,550,174 A discloses a method and corresponding tools for producing internal threads and grooves. On a conically shaped shaft sits a cylindrical sleeve which includes a thread forming profile. This sleeve is movably mounted and fixed on the shaft. The tool is inserted into an opening or bore and oscillated by means of a drive. During the rotating movement of the shaft, a force acts on the sleeve longitudinally parallel to the geometric axis of the device. The sleeve moves along the conical shaft and is thereby widened. This causes the thread profile to be pushed deeper into the material, thereby affecting the depth of the thread form.

US 2,400,187 A deals with a rotary cutting tool with arranged on a shaft and exchangeable cutting means. These have at both ends a seat and a base.

DE 28 52 906 A1 describes an internally threaded rifling with a friction part mounted at its free end. The outer diameter of the friction member corresponds to the core diameter of the internal thread to be furrowed and its cutting edges are effective in the opposite direction to the screwing of the Furchers direction.

WO 96/07502 A1 shows an integral rotatable tool for forming holes and tapping the holes. By means of a circular movement, a cutting tool is moved within a bore and creates an internal thread.

It is an object of the invention to provide a new tool and a new method for producing a thread, in particular for producing an internal thread.

This object is achieved in terms of the tool with the features of claim 1 and in terms of the method with the features of claim 53. Advantageous embodiments and further developments of the tool and the method according to the invention will become apparent from the claims dependent respectively from claim 1 and claim 53.

The tool according to claim 1, designed as a circular thread former, is suitable for producing or reworking a thread, in particular an internal thread, and comprises at least one carrier body (or: base body, in particular tool shank, tool core), through which a tool axis (or: axis of rotation, preferably a main axis of inertia), and at least one prefabricated and / or separate thread forming element (or: thread forming part, thread forming body), which is fastened to the support body and optionally further thread forming elements by means of fastening means in an associated position, as well as either annularly rotates the tool axis or disc-shaped is, wherein the tool axis passes through the thread forming element. Each thread forming element has at least one radially outwardly projecting (or: projecting) thread forming profile for chipless production or reworking of the thread by impressing (or: molding) the thread forming profile, in particular one or more forming wedges of the thread forming profile, into a workpiece surface during a circular forming movement, that is to say a rotation of the carrier body with the attached thread forming element (s) about the tool axis and a simultaneous helical and / or spiral feed movement of the carrier body with the thread forming element (s) about a central axis of rotation parallel to the tool axis and spaced from the tool axis.

The method according to claim 53 is a circular thread forming or comprises at least one circular thread forming for producing or post-processing a thread. In the method, a tool according to the invention is used and rotated on the one hand about its tool axis and on the other hand with an axial feed movement along a feed direction parallel to the tool axis relative to a workpiece is moved and moves in addition to the axial feed movement with a circular motion in which the tool axis to a central axis of rotation is rotated parallel to the tool axis. In this combined working movement, the at least one thread-forming profile of the tool is brought into engagement with a workpiece surface and the thread is produced or reworked without cutting by impressing the thread-forming profile, in particular of the molding wedge (s), into the workpiece surface.

The fastening means for attaching the thread forming elements to the carrier body and / or to one another or to one another may comprise at least one material-locking connection, in particular a solder connection, and / or at least one frictional connection, in particular a connection via thermal shrinking, and / or at least one positive connection. Preferred embodiments of the fastening means are interlocking polygons and / or opposing wedge surfaces. Particularly advantageous are fastening means with cooperating pairs of projection and corresponding recess or opening, wherein the engagement direction or engagement action of at least one projection in the corresponding recess or opening in one embodiment is directed substantially radially to the tool axis, for example as a circumferential or a spline, or is directed in another embodiment substantially axially or parallel to the tool axis, for example in the manner of a Hirth toothing or star-shaped locking.

The fastening means are preferably reversibly detachable, in particular by means of at least one screw connection, which preferably has at least one screw which can be screwed through at least one thread forming element, in particular through a central opening, preferably coaxial with the tool axis, and a counter thread on the carrier body. In addition, the fastening means may also comprise at least one fastening element, in particular a clamping wedge, which is releasably fixed or releasably secured to the carrier body via at least one connecting means, in particular a screw connection, wherein at least one thread forming element between the carrier body and the at least one fastening element and / or between at least two fasteners positively and / or non-positively and releasably fixed or fixed and preferably each fastener and each connecting means is respectively disposed outside of the thread forming element and neither penetrates neither the thread forming element is still enclosed by the thread forming element.

In a particular embodiment, the attachment means permit attachment of at least one, preferably each, thread forming element in a plurality of rotational positions about the tool axis. For this purpose, in particular a plurality of projections arranged in different rotational positions about the tool axis and of projections be provided corresponding recesses or openings, as in the already mentioned gearing types.

A particularly robust embodiment of the fastening means comprises at least one, preferably central and / or coaxial to the tool axis, opening in the thread forming element and a corresponding opening to the opening attachment shaft on the carrier body in the opening (s) of the thread or the forming elements (s), preferably positively, is inserted or inserted and / or flush with an end face of the or the (foremost) thread forming element.

In a particularly advantageous embodiment, at least one thread-forming profile is substantially perpendicular to the tool axis, the tool axis closed in itself and / or formed in the form of a circumferential axis of the tool substantially annular groove.

Also particularly advantageous is a tool having a plurality of thread forming elements or at least one thread forming element with a plurality of thread forming profiles, wherein the thread forming profiles are each arranged axially to the tool axis one behind the other and simultaneously can produce a plurality of threads with a working movement of the tool. At least two thread forming elements may then be connected or coupled together via one or more of the attachment means.

In general, at least one thread-forming profile has at least one molding wedge (or: pressing lug, forming tooth) which projects radially outward of the tool axis to the outside than the immediately adjacent regions of the thread-forming profile. The shaped wedges of axially offset thread forming profiles can now be arranged in a substantially axial arrangement running parallel to the tool axis or even in an essentially tool axis at least partially, preferably helically or obliquely, in a circumferential or twisted arrangement.

Preferably, at least one thread forming element and / or at least one thread forming profile is rotationally symmetrical with respect to the tool axis with an n-fold rotational symmetry with the natural number n greater than or equal to 1 or arranged and / or has in a section perpendicular to the tool axis one of a, preferably regular, Polygon derived form, wherein the polygon preferably has a corner number of two or three or four or five or six and / or corner portions of the at least approximately polygonal section of the thread forming element or thread forming profile form the mold wedges.

In one development, at least one thread-forming element or at least one thread-forming profile has a plurality of subregions offset from one another in the direction of rotation about the tool axis and, in particular, separated by separating grooves, is thus segmented in the circumferential direction.

In an advantageous development, the maximum radial distance of the axially successively arranged thread forming profiles, in particular of the shaped wedges, from the tool axis against an axial feed direction and / or directed away from one end of the tool at least partially in a starting region of the tool, preferably linear (starting cone) , too. As a result, an increasing radial engagement to the full engagement in the axial feed along the screw or circular motion can be realized. But even with the same radial distances of the thread forming profiles, the engagement can be made increasingly smaller at the beginning by a Einfahrschleife or retraction, in which the radial delivery of the tool to the workpiece is varied according to the workpiece until the actual screw movement reaches a constant radial delivery becomes.

By means of the measures according to the invention, a modular or modular design of the circular thread former is possible, in which the number and / or shape of the shaped wedges can be chosen differently for at least two thread forming profiles with the same carrier body through the individually configurable and mountable thread forming element and thread forming profiles. This opens up a wealth of different, customized for the application embodiments.

Thus, the tool can have at least two sets of thread forming elements, in particular with different axial and / or radial dimensions and / or different thread forming profiles, for producing or reworking threads of different thread pitches and / or thread depths and / or thread diameters and / or thread cross sections and / or thread surface qualities ,

The tool is preferably exclusively work without cutting or a pure mold, thus has no cutting area and / or no cutting edge.

In a particular embodiment of the tool as a combination tool, however, at least one additional cutting area provided, in particular for producing a workpiece surface or a Vorgewindes for the thread, which is produced or reworked by the or the thread profile (s) or for producing a, in particular with respect to a thread core, enlarged, in particular stepped or chamfered, entrance area or mouth region of the thread and / or for trimming or leveling the thread core of the thread produced by the thread forming profile (s).

At least one additional cutting area is arranged at least partially on a front side or a free end of the tool and / or a drill and / or a milling cutter and / or has at least one frontal cutting edge on a front side or a free end of the tool and / or at least one circumferential cutting edge on a peripheral region of the tool

At least one additional cutting area and at least one thread forming area are preferably arranged one behind the other in a predetermined order axially of the tool axis.

Furthermore, the tool can have grooves and / or channels for guiding a fluid medium, in particular a coolant and / or lubricant, wherein the grooves and / or channels preferably extend on the circumference of the tool and / or in the interior of the tool and / or in the thread forming element and / or open, in particular at least with a main direction parallel to the tool axis and / or straight or twisted or helical about the tool axis and / or in the longitudinal direction of the tool.

The carrier body is usually a tool shank or tool core, which is received with its end remote from the workpiece or free end in the chuck of a machine tool and held rotatably.

• 1 ein ringförmiges Gewindeformelement mit vier Formkeilen für einen Zirkulargewindeformer in einer perspektivischen Darstellung,
• 2 ein Teilausschnitt eines Zirkulargewindeformers mit einem Gewindeformelement gemäß 1 in einer perspektivischen Darstellung,
• 3 ein weiterer Zirkulargewindeformer mit mehreren hintereinander angeordneten Gewindeformelementen gemäß 1 in einer perspektivischen Darstellung,
• 4 ein Längsschnitt durch den Zirkulargewindeformer gemäß der in 3 mit IV-IV bezeichneten Schnittebene,
• 5 ein ringförmiges Gewindeformelement mit vier Formkeilen und Kreuzschlitzen zur formschlüssigen Verbindung in einer perspektivischen Ansicht,
• 6 das Gewindeformelement gemäß 5 mit einer flachen Stirnseite in einer um 180° gedrehten perspektivischen Ansicht,
• 7 ein Teil eines Zirkulargewindeformers mit einem mit einer Schraube befestigten Gewindeformelement gemäß 5 und 6 in einer perspektivischen Ansicht,
• 8 ein Gewindeformelement mit gekreuzten Vorsprüngen zur formschlüssigen Verbindung mit einem Element gemäß 5 in einer perspektivischen Ansicht und
• 9 das Gewindeformelement gemäß 8 mit gekreuzten Nuten an der anderen Stirnseite in einer um 180° gedrehten perspektivischen Ansicht,
• 10 ein Zirkulargewindeformer mit einer mit einer Schraube montierten Gewindeformanordnung mit fünf am Außenprofil analog wie in 5 und 6 und 8 und 9 aufgebauten Gewindeformelementen in einer perspektivischen Ansicht.
• 11 ein Zirkulargewindeformer mit einem Gewindeformelement mit nur einem Formkeil in einer perspektivischen Ansicht,
• 12 ein Zirkulargewindeformer mit mehreren Gewindeformelementen mit jeweils nur einem Formkeil, wobei die Formkeile in einer linearen Anordnung angeordnet sind, in einer perspektivischen Ansicht,
• 13 ein Zirkulargewindeformer mit mehreren Gewindeformelementen mit nur einem Formkeil, wobei die Formkeile in einer schraubenförmigen Anordnung zueinander versetzt sind, in einer perspektivischen Darstellung,
• 14 ein Zirkulargewindeformer mit mehreren Gewindeformelementen mit jeweils einem Gewindeformkeil, wobei die Formkeile um 90° zueinander versetzt sind, in einer perspektivischen Ansicht und
• 15 ein Zirkulargewindeformer mit mehreren Gewindeformelementen mit jeweils zwei um 180° zueinander versetzten Formkeilen, in einer perspektivischen Ansicht,

die jeweils schematisch dargestellt sind.The invention will be explained below with reference to exemplary embodiments. It is also referred to the drawing, in whose

• 1 an annular thread forming element with four mold wedges for a circular thread former in a perspective view,
• 2 a partial section of a circular thread former with a thread forming element according to 1 in a perspective view,
• 3 another circular thread former with a plurality of successively arranged thread forming elements according to 1 in a perspective view,
• 4 a longitudinal section through the circular thread former according to the in 3 sectional plane designated IV-IV,
• 5 an annular thread forming element with four shaped wedges and Phillips for positive connection in a perspective view,
• 6 the thread forming element according to 5 with a flat face in a 180 ° rotated perspective view,
• 7 a part of a Zirkulargewindeformers with a fastened with a screw thread forming element according to 5 and 6 in a perspective view,
• 8th a thread forming element with crossed projections for positive connection with an element according to 5 in a perspective view and
• 9 the thread forming element according to 8th with crossed grooves on the other end in a perspective view rotated by 180 °,
• 10 a circular thread former with a screw-mounted thread forming arrangement with five on the outer profile analogous to in 5 and 6 and 8th and 9 constructed thread forming elements in a perspective view.
• 11 a circular thread former having a thread forming element with only one forming wedge in a perspective view,
• 12 a circular thread former having a plurality of thread forming elements each having only one forming wedge, wherein the forming wedges are arranged in a linear arrangement, in a perspective view,
• 13 a circular thread former having a plurality of thread forming elements with only one forming wedge, wherein the forming wedges are offset in a helical arrangement to each other, in a perspective view,
• 14 a circular thread former having a plurality of thread forming elements, each with a thread forming wedge, wherein the mold wedges are offset by 90 ° to each other, in a perspective view and
• 15 a circular thread former with a plurality of thread forming elements, each with two 180 ° offset from each other wedge molds, in a perspective view,

which are each shown schematically.

Corresponding parts and sizes are in the 1 to 15 provided with the same reference numerals.

1 shows an annular thread forming element 20, which is a self-contained a central tool axis A revolving radially from the tool axis A Outwardly projecting thread forming profile 10 that is derived from a (regular) polygon with a given corner number. in the present embodiment of a square with four corners. The corners of the thread forming profile 10 form mold wedges (or: punch holes, furrows) 11, 12, 13 and 14 and are rounded off from the original polygonal shape. The illustrated thread forming element 20 has a multiple rotational symmetry with respect to the tool axis A whose symmetry number corresponds to the corner number of the polygon, in the example of 1 a fourfold rotational symmetry.

2 shows the thread forming element 20 in a on a tool shank 3 a tool designed as a circular thread former 2 mounted and fastened state. The thread forming element 20 has a central, cylindrical opening 15 on, by according to 2 a at the front of the tool shank 3 arranged cylindrical attachment shaft 5 is guided. The front side 30 of the attachment shaft 5 preferably closes flush with the front face 27 of the thread forming element 20 from.

The attachment of the thread forming element 20 to the attachment shaft 5 can by a material-locking connection, such as a solder joint, between the inner surface of the opening 15 and the outer surface of the attachment shaft 5 carried out or by a non-positive connection, for example, thermal shrinkage by, for example, inductive, heating and subsequent cooling. When soldering, the diameter of the attachment shaft 5 chosen slightly smaller than the inner diameter of the opening 15 for a soldering gap for the soldering material. Instead of the cylindrical shape of the opening 15 and attachment shaft 5 it is also possible to provide a conical or polygonal shape in order to adapt the seat of the thread forming element 20 or to add a form-locking connection, wherein in the case of a polygonal shape, a rotation or adjustment in different rotational positions is possible, in particular at individual rotational angle intervals of 360 ° divided by the polygon -Eckenzahl.

The thread profile 10 the thread forming element 20 thus forms a circumferential, self-contained thread groove with different radius or diameter, wherein at the mold wedges 11 to 14 the actual mold areas or active surfaces are formed, which protrude radially further outward than the remaining areas of the thread forming profile 10 , The thread profile 10 of the thread forming member 20 thus engages upon rotation of the circular thread former 2 around its tool axis A essentially only with the shaped wedges 11 to 14 successively or successively in the material of the workpiece and generates the thread by pressing and deforming the material. Depending on the delivery of the tool 2 to the workpiece engages a different engagement length or engagement effective area of the thread profile 10 and the mold wedges 11 to 14 into the workpiece.

To create the thread is used with the tool 2 worked according to the invention as follows. The tool becomes, as in 2 shown to his tool axis A rotates with a RB designated rotational movement. At the same time the tool becomes 2 axially to the tool axis A linear with a feed motion VB moved and at the same time with a rotary motion or circular motion For example, one parallel to the tool axis A arranged central axis M moves. Due to the superimposition of the axial feed motion VB and the circular movement For example, creates a screw movement on a cylindrical surface, the slope of the feed rate in the feed motion VB depends, and if this feed rate is constant, is also constant. The helical shape of the screw movement of the tool 2 forms on the helical shape of the thread in the workpiece. The rotational speed or rotational speed of the rotational movement RB around the work train axle A is chosen much larger than the rotational speed of the circular motion For example, of the tool 2 around the central axis M, typically by a factor 50 up to 1000 larger.

3 and 4 show a trained as a circular thread forming tool 2 in which several Thread forming elements 21, 22, 23, 24 and 25 axially to the tool axis A one behind the other on a common attachment shaft 5 of the tool shank 3 are attached. The arrangement of the thread forming elements 21 to 25 may consist of individual thread forming elements 20 according to 1 , which are mounted individually, or from a preassembled unit of the five thread forming elements 21 to 25, which are then mounted together, be formed. In the embodiment shown, the mold wedges of the thread forming elements 21 to 25 are each on a parallel to the tool axis A arranged extending line, the thread forming elements 21 to 25 so not rotated against each other.

As in the longitudinal section of the 4 To recognize, the outer radius or the maximum radial dimension of the individual thread profiles of the thread forming elements 21, 22, 23, 24 and 25 increases from the end face or the front end 30 axially to the tool axis A to the rear, ie against the feed direction of the feed movement VB to. So it's an increase in the outer radii r1 to r5 the thread forming elements 21 to 25 against the feed movement VB realized, so r1>r2>r3>r4> r5, and thus an entire radius difference dr formed between the smallest outer radius r1 and the largest outer radius r5. As a result of this configuration as a starting region, the individual grooving teeth or shaped wedges of the thread forming elements 21 to 25 press during the advancing movement VB and constant distance of the tool axis A from the workpiece successively deeper into the material of the workpiece and thus successively produce the thread up to the full thread depth r5. As a result, the forming forces to be performed by the individual rake teeth or shaped wedges are distributed uniformly over the various thread forming elements 21 to 25. Im in 4 illustrated embodiment also take the between the individual grooves or thread profiles of the thread forming elements 21 to 25 lying intermediate areas in their radius, so that the height of the teeth remains substantially the same. The gaps can also have a constant or the same radius, so that the tooth height increases axially. The distance a between the furrow teeth or thread profiles of the individual thread forming elements 21 to 25 is in each case the same and corresponds to the desired pitch or the desired spacing of the thread grooves or threads of the thread produced. As a result, the following teeth or thread forming elements always follow in the threads produced by the previous thread teeth.

In 5 and 6 is another embodiment of a thread forming element 80 shown from two sides. At a first end 181 has the thread forming element 80 two crossed grooves 183 and 184 on, in the middle of the crossing there is a central opening 185 located. On the opposite front side 182 the opening widens 185 via a recess 186 larger diameter on, as in 7 shown a screw head of a screw 18 for fastening the thread forming element 80 on the shaft 3 of the tool 2 to allow and sink the screw head. The thread forming element 80 has four corner areas as shaped wedges 80A to 80D and is preferably rotationally symmetrical (here four-fold symmetry) formed.

8th and 9 show a thread forming element 81 from two sides. This thread forming element 81 has, as in 9 to recognize, on a front side 181 the same structure with grooves 183 and 184 and opening 185 on like the thread forming element 80 according to 5 , At the opposite end 282 However, the thread forming element 81 is formed differently than the thread forming element 80 and has two crossed and through the central opening instead of a flat surface 285 interrupted by 90 ° to each other arranged projections or webs 283 and 284 on, on the grooves 183 and 184 are adjusted. As a result, a thread forming element 81 can be connected in a form-fitting manner one after the other with a plurality of other identically constructed thread forming elements and arranged axially one behind the other in a fixed rotational position relative to one another. The rotational position of the thread forming element relative to the tool axis can vary depending on the rotational symmetry of the thread forming elements and the number of projections and grooves or their angular distance.

10 shows an arrangement with five individual thread forming elements 80 , 81, 82, 83 and 84, wherein preferably the foremost thread forming element 80 according to 5 and 6 is designed and the central opening 185 and recess 186 for receiving the screw 18 and the screw head has and the other thread forming elements 81 to 84 according to 8th and 9 are constructed and latched or plugged with their respective projections and grooves. Also the tool shank 3 can projections as in 8th have to receive the rearmost thread forming element positively. As a result, by the positive connection a security against rotation and by the screw 18 ensures the axial security.

An embodiment with only one mold wedge 61 equipped thread forming element 40 shows 11 , The thread forming element 40 is formed as a drop-shaped or egg-shaped or cam-shaped ring and has a tool axis A circumferential thread profile 60 on, in an at least approximately circular section 64 and two immediately adjacent and in the mold wedge 61 converging straight sections 63 is divisible. The tool shank 3 again has a fastening shaft 5 on, which is also teardrop-shaped or egg-shaped and on which the thread forming element 40 is plugged in a form-fitting manner and is fastened, for example materially by soldering or non-positively by shrinking. At the front end of the attachment shaft 5 is a central opening 50 provided for supplying lubricant and / or coolant. When mounted with a screw connection, the opening could 50 also serve to receive a screw.

12 shows an embodiment in which a plurality of thread forming elements 40 formed like the thread forming element 41 to 48 axially to the tool axis A one behind the other on the attachment shaft 5 are arranged, the mold wedges 61 in a straight line parallel to the tool axis A are arranged.

In 13 and 14 are the mold wedges 61 the thread forming elements 41 to 48 in each case at one, preferably the same, angle of rotation or helix angle to the front end as seen to the left to the respective preceding wedge shape 61 arranged offset, resulting in a helical arrangement of the mold wedges 61 results. In 13 the offset rotation angle is significantly smaller than 90 °, eg 2 ° to 25 °, while in 14 an offset or helix angle is realized by 90 °. The helix angle can be varied over the circumference for different loop angles or engagement lengths.

In 15 Finally, there are several nut or double cam-shaped annular thread forming elements 91 to 98 each with two diametrically opposite shaped wedges 71 and 72 axially one behind the other on a mounting shaft 5 of the tool shank 3 fixed in a form-fitting manner. Two outer circular sections 74 the respective thread forming profiles go over straight sections 73 each in the rounded mold wedges 71 and 72 above.

Furthermore, additional wear protection layers can be applied to the tool or its working areas. It is particularly advantageous if the tool shank is made of a tool steel, in particular a high-speed steel. This can be, for example, a high-speed steel (HSS steel) or a cobalt-alloyed high-speed steel (HSS-E steel). The working areas are preferably made of hard metal or of a hard metal alloy, in particular P-steel or K-steel or cermet, or sintered hard metal or a cutting ceramic, in particular tungsten carbide or titanium nitride or titanium carbide or titanium carbonitride or aluminum oxide, polycrystalline boron nitride (PKB) or polycrystalline Diamond (PCD) made.

LIST OF REFERENCE NUMBERS

2

thread tools

3

shaft

5

mounting shaft

10

Thread-forming profile

11 to 14

form wedges

15

opening

18

screw

20 to 25

Tapping element

27

face

30

face

41 to 48

Tapping element

50

opening

60

Thread-forming profile

61

form wedges

63, 64

profile section

70

Thread-forming profile

71, 72

form wedges

73, 74

profile section

80

Tapping element

80A to 80D

form wedges

81 to 84

Tapping element

81A to 81D

form wedges

91 to 98

Tapping element

181, 182

front

183, 184

groove

185

opening

186

recess

281, 282

front

283, 284

head Start

285

opening

A

tool axis

r1 to r5

outer radius

a

distance

dr

radius difference

VB

feed motion

RB

rotational motion

For example,

circular movement

Claims (59)

Tool, designed as a circular thread former, for producing or reworking a thread, in particular an internal thread, comprising a) at least one carrier body (3) through which a tool axis (A) extends, b) at least one thread forming element (20), b1) as a prefabricated and / or a separate part is formed and b2) is fastened to the carrier body (3) by means of fastening means (5, 15), and b3) is ring-shaped around the tool axis (A) or b4) is disc-shaped, the tool axis (A) passing through the thread forming element (20) extends, and d) wherein each thread forming element (20) at least one radially to the tool axis (A) outwardly projecting thread forming profile (10) for non-cutting generating or reworking of the thread by pressing the thread forming profile (10) into a workpiece surface upon rotation of the carrier body (3) the thread forming element (s) (20) about the tool axis (A) and a simultaneous helical and / or spiral feed movement (VB, ZB) of the carrier body (3) with the thread forming element (s) (20) around the tool axis (A) parallel and from the tool axis (A) spaced central axis of rotation (M). Tool after Claim 1 in which the fastening means (5, 15) comprise or are at least one material-bonding connection. Tool after Claim 1 or Claim 2 in which the fastening means (5, 15) comprise or are at least one frictional connection. Tool after one of Claims 1 to 3 in which the fastening means (5, 15) comprise or are at least one positive connection. A tool as claimed in any one of the preceding claims, wherein the attachment means (5, 15) comprise or are interdigitated or interlocking polygons. Tool according to one of the preceding claims, in which the fastening means (5, 15) comprise or are engaging polygons which engage against one another. A tool according to any one of the preceding claims, wherein the attachment means (5, 15) comprise or are cooperating projections (283, 284) or projections and corresponding recess (s) (186) or openings (15, 50). Tool after Claim 7 in which at least one projection (283, 284) engages substantially radially with respect to the tool axis (A) into the corresponding recess (s) (186) or opening (s) (15, 50). Tool after Claim 7 in which at least one projection (283, 284) engages in the corresponding recess (s) (186) or opening (s) (15, 50) substantially axially or parallel to the tool axis (A). Tool according to one of the preceding claims, in which at least one fastening means (5, 15) is reversibly detachable. Tool after Claim 10 in that the fastening means (5, 15) enable a fixing of at least one thread forming element (20) in a plurality of rotational positions about the tool axis (A). Tool after Claim 11 in which the fastening means (5, 15) comprise a plurality of projections and corresponding recesses (186) or openings (15, 50) arranged in different rotational positions about the tool axis (A). Tool after one of Claims 10 to 12 in which the reversibly releasable fastening means (5, 15) comprise at least one screw connection. Tool after Claim 13 in which at least one screw connection of the reversibly releasable fastening means (5, 15) comprises at least one screw (18) which can be passed through or passed through at least one thread forming element (20), through a central opening (15, 50) running coaxially to the tool axis, and a mating thread on the carrier body (3) for screwing in the screw (18). Tool according to one of the preceding claims, in which a) the fastening means (5, 15) at least one fastening element which on the carrier body (3) via at least one connecting means, in particular a screw, releasably fixable or releasably fixed include b) wherein at least one thread forming element (20) between the carrier body (3) and the at least one fastening element and / or between at least two fastening elements positively and / or non-positively and releasably fixed or fixed, c) wherein each fastening element and each connecting means in each case outside of the thread forming element (20) is arranged and in each case neither the thread forming element (20) penetrates nor is enclosed by the thread forming element (20). Tool according to one or more of the preceding claims, in which the or each thread forming element (20) has at least one central opening (15, 50) extending coaxially with the tool axis (A) and the carrier body (15) as fastening means (5, 15). 3) has a fastening shaft corresponding to the opening (15, 50), which is preferably insertable, insertable or inserted into the opening (s) (15, 50) of the thread forming element or elements (20). Tool after Claim 16 in which an end face (30) of the attachment shaft (5) is flush with an end face (27) of the or the foremost thread-forming element (20) closes. Tool according to one or more of the preceding claims, wherein at least one thread-forming profile (10) substantially perpendicular to the tool axis (A), the tool axis (A) closed in itself and / or in the form of a tool axis (A) encircling substantially annular groove is trained. Tool according to one of the preceding claims with a plurality of thread forming elements (20 to 25), which are arranged axially to the tool axis (A) one behind the other. Tool according to one of the preceding claims, wherein at least two thread forming elements (20 to 25) are connected or coupled to one another via one or more of the fastening means (5, 15). Tool according to one or more of the preceding claims, in which at least one thread-forming element (20) has a plurality of thread-forming profiles (10) which are arranged axially one behind the other relative to the tool axis (A). Tool according to one or more of the preceding claims, in which at least one thread-forming profile (10) has at least one forming wedge (11 to 14) which projects radially outward from the tool axis (A) to the outside than the directly adjacent regions of the thread-forming profile (10). Tool after Claim 22 and one of the Claims 20 and 21 in which the shaped wedges (11 to 14) of axially offset threaded profile sections (10) are arranged in a substantially axial arrangement parallel to the tool axis (A). Tool after Claim 22 and one of the Claims 20 and 21 in which the mold wedges (11 to 14) of axially offset from each other thread form profiles (10) in a substantially the tool axis (A) at least partially helically or obliquely encircling or twisted arrangement are arranged. Tool according to one or more of the preceding claims, wherein at least one thread forming element (20) and / or at least one thread forming profile (10) rotationally symmetrical with respect to the tool axis (A) formed with an n-fold rotational symmetry with the natural number n greater than or equal to 1 or are arranged or is. Tool according to one of the preceding claims, in which at least one thread forming element (20) or thread forming profile (10) has a shape derived from a polygon in a section perpendicular to the tool axis (A), the polygon preferably having a corner number of two or three or four or five or six. Tool after Claim 26 in a backward relationship Claim 22 , wherein corner regions of the at least approximately polygonal section of the thread forming element (20) or thread profile (10) form the mold wedges (11 to 14). Tool according to one or more of the preceding claims, in which at least one thread-forming element (20) or at least one thread-forming profile (10) has a plurality of sub-regions which are offset and offset relative to one another in the direction of rotation about the tool axis (A). Tool according to one or more of the preceding claims, wherein the maximum radial distance of axially successively arranged thread forming profiles (10) of the tool axis (A) against an axial feed direction and / or directed away from one end of the tool at least in a starting region of the tool at least increases in sections. Tool after Claim 29 in which the maximum radial distance increases at least in sections linearly. Tool after Claim 22 or one of Claim 22 dependent claims, wherein the number and / or shape and / or arrangement of the mold wedges (11 to 14) differ / at least two thread-forming profiles (10). Tool according to one or more of the preceding claims with at least two sets of thread forming elements (20), with different axial and / or radial dimensions and / or different thread forming profiles (10), for producing or reworking threads of different thread pitches and / or thread depths and / or Thread diameter and / or thread cross sections and / or thread surface qualities. Tool according to one or more of the preceding claims with at least one additional cutting area in addition to the thread forming area (s). Tool after Claim 33 in which a) at least one additional machining area is designed and provided for producing a workpiece surface for the thread and in which b) the at least one thread forming profile (10) is designed and provided for producing the thread in this workpiece surface. Tool after Claim 33 or Claim 34 in which a) at least one additional cutting area is designed and provided for cutting a preliminary thread in a workpiece surface and wherein b) the thread forming profile or profiles (10) for finishing the thread are formed by reworking the preliminary thread in the workpiece surface and is provided. Tool according to one or more of Claims 33 to 35 in which at least one additional machining area is arranged at least partially on an end face or a free end of the tool. Tool according to one or more of Claims 33 to 36 in which at least one additional cutting area is a drilling area. Tool according to one or more of Claims 33 to 37 in which at least one additional cutting area is a milling area. Tool according to one or more of Claims 33 to 38 in which at least one additional machining area has at least one end-side cutting edge on a front side or a free end of the tool and / or at least one peripheral-side cutting edge on a peripheral region of the tool Tool according to one or more of Claims 33 to 39 in which at least one additional cutting area is designed and provided for producing an enlarged or in particular stepped or chamfered entry area or opening area of the thread relative to a thread core. Tool according to one or more of the preceding claims, in which at least one thread-forming profile (10) is provided for reworking and / or leveling of the threads or thread flanks of the thread. Tool according to one or more of Claims 33 to 41 in which at least one additional cutting area and at least one thread forming area are arranged axially in relation to the tool axis (A) one behind the other in a predetermined order. Tool according to one or more of the preceding claims, wherein adjoining the at least one thread-forming profile (10) or thread-forming element (20) is a cutting area with at least one core cutting edge for regrooving or leveling the thread core of the thread forming profile (s) (10) ) generated thread. Tool after Claim 43 in which at least one thread forming area adjoins the cutting area with the core cutting edge for subsequent processing and / or leveling of the threads or thread flanks of the thread. Tool according to one or more of Claims 33 to 44 in which at least one additional cutting area is designed for a return direction of the tool directed opposite to the predetermined axial feed direction of the tool and axially of the tool axis (A). Tool according to one or more of Claims 33 to 45 in which the at least one thread-forming profile (10) protrudes radially outward with respect to the tool axis (A) or has a larger maximum radial outer diameter than at least one additional cutting area arranged closer to the free end of the tool than the thread-forming profile (10) in the feed direction , Tool according to one or more of Claims 33 to 46 in which the at least one thread-forming profile (10) protrudes less far radially outward with respect to the tool axis (A) or has a smaller maximum radial outer diameter than at least one cutting area further in the feed direction from the free end of the tool than the thread-forming profile (10) , Tool according to one or more of Claims 33 to 47 in which at least one chip-removing region is formed on the carrier body (3) or produced by material removal. Tool according to one or more of Claims 33 to 48 in which at least one cutting area is formed on at least one prefabricated part or formed from a prefabricated part and in which the prefabricated part on the carrier body (3) by means of fastening means (5, 15) is releasably or permanently attached. Tool according to one or more of the preceding claims, wherein the carrier body (3) is designed as a tool shank or tool core. Tool according to one of the preceding claims, in which the tool axis (A) is a main axis of inertia of the carrier body (3). Tool according to one of the preceding claims with grooves (183, 184) and / or channels for guiding a fluid medium, wherein the grooves (183, 184) and / or channels preferably on the circumference of the tool and / or inside the tool and / or in the thread forming element (20) and / or open, at least with a main direction parallel to the tool axis (A) and / or straight or twisted or helical about the tool axis (A) and / or in the longitudinal direction of the tool. Method for producing or reworking a thread, in which a) a tool according to one or more of the preceding claims a1) is rotated about its tool axis (A), a2) with an axial feed movement (VB) along a feed direction parallel to the tool axis (A) is moved relative to a workpiece and a3) is moved in addition to the axial feed movement (VB) with a circular movement (ZB) in which the tool axis (A) is rotated about a central axis of rotation parallel to the tool axis (A), b) and in which the thread is produced with the at least one thread-forming profile (10) without cutting or the preliminary thread is reworked by impressing the thread-forming profile (10) into a workpiece surface. Method according to Claim 53 in which the central axis of rotation substantially coincides with a central axis of the thread to be created or created. Method according to Claim 53 or 54 for producing an internal thread, wherein the workpiece surface forms the inner surface of a recess (186), or a through-going opening (15, 50). Method according to one of Claims 53 to 55 in which the feed rate and / or the return speed are adapted to the gradient of the thread to be generated or produced. Method according to one of Claims 53 to 56 , is performed at a, in particular loop and / or spiral retracting movement of the tool, wherein the tool axis (A) of the tool is approached or delivered from an initial position of the workpiece surface until the spacing of the tool axis (A) from the central axis of rotation of the circular motion (Eg) is reached. Method according to one of Claims 53 to 57 in which a predetermined or predefinable workpiece surface of a workpiece is produced with at least one machining area of the tool and / or a pre-thread is produced in a workpiece surface of a workpiece. Method according to one of Claims 53 to 58 in which a predetermined or predefinable workpiece surface of a workpiece and / or a pre-thread in a workpiece surface of a workpiece is not produced or produced with a cutting area of the tool itself.

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