US20150165501A1

US20150165501A1 - Thread rolling head

Info

Publication number: US20150165501A1
Application number: US14/572,160
Authority: US
Inventors: Stefan Janke; Raphael Lienau; Christian Gutsche; Uwe Kretzschmann; Adam Beben
Original assignee: LMT Fette Werkzeugtechnik GmbH and Co KG
Current assignee: LMT Fette Werkzeugtechnik GmbH and Co KG
Priority date: 2013-12-17
Filing date: 2014-12-16
Publication date: 2015-06-18
Also published as: BR112016014005A2; ES2593380T3; WO2015091111A1; CN105934294A; CN105934294B; MX2016007750A; EP2886224A1; EP2886224B1

Abstract

A thread rolling head comprises a bearing unit, in which at least two profile rollers, preferably at least three profile rollers, are rotatably mounted, and a shank section coupled to the bearing unit. Adjacent profile rollers delimit an insertion section into which a workpiece to be machined can be inserted. The bearing unit is built from at least two modules each forming a functional unit, wherein the modules each have a fastener through which modules can be connected together and can be exchanged for other modules also each forming a functional unit. One of the modules has fasteners for connecting to corresponding fasteners of the shank section.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to EP 13 197 742.3, filed Dec. 17, 2013, the content of which is incorporated herein in its entirety by reference.

FIELD OF THE DISCLOSURE

The disclosure relates in general to a thread rolling head.

BACKGROUND

Thread rolling heads can be, for example, axial thread rolling heads or radial thread rolling heads. They can have, for example, three profile rollers uniformly distributed about an insertion section. A workpiece, cylindrical for example, can be inserted in the longitudinal direction into the insertion section. With axial thread rolling heads, machining (that is, forming the threads) on the workpiece occurs in the course of insertion into the insertion section. With radial thread rolling heads, the profile rollers for machining are positioned radially onto the workpiece after the insertion of the workpiece. Generally, there is additionally an opening mechanism with which the profile rollers can be displaced between a machining position and an open position, in which they are displaced radially outward. After the machining process, the rollers are moved into the open position, and the thread rolling head can be removed from the workpiece without collision. Furthermore, the cross-section of the insertion section may be adapted by adjusting the spacing of the profile rollers to each other. In this manner, the thread rolling head can be adapted to different workpieces to be machined and be precisely adjusted.
Thread rolling heads are complex systems composed of a plurality of individual parts. This complexity is due to the requirements of the thread rolling heads, among others small construction size and simultaneous coverage of a large machining range. A thread rolling head is known, for example, from German document DE 44 30 184 C2. Here, on a shank that can be fixed in a machine tool, a coupling section extends through a spring housing composed of a plurality of components into a gearing mechanism arranged at an intermediate plate of the thread rolling head. A front plate is fastened to the intermediate plate using screw connections. Three profile rollers, each on an eccentric shaft, are held mounted rotatably between the front plate and the intermediate plate. The fastening occurs via distance bolts, arranged between the front plate and the intermediate plate, into which threaded pins are screwed from the one side through the front plate, and which comprise an external thread on the other end thereof that extends through the intermediate plate and the spring housing up to the shank. Lock nuts are screwed onto the external thread of the distance bolts.
A further thread rolling head is known from European document EP 1 555 072 B1. With this thread rolling head, a fixing section of the shank for fixing into a metal-cutting machine on the one side and a coupling section of the shank for coupling to the bearing unit of the thread rolling head on the other side are separated parts that are connected together axially and releasably fixed against rotation via connecting sections. In this manner it is possible to provide another fixing section of the shank, wherein the coupling section of the shank remains connected to the bearing unit of the thread rolling head. In the same manner, a plurality of different thread rolling heads can be used in a fixing machine.

BRIEF SUMMARY

During operation, thread rolling heads and thus also the individual thread rolling components experience wear. Worn out parts must be replaced. Due to the complex assembly and disassembly of known thread rolling heads, replacing parts is complex and requires extensive knowledge of the thread rolling head. This can represent a problem especially for a customer using the thread rolling head. Thread rolling heads, such as those described in the document DE 44 30 184 C2, must be nearly completely disassembled for maintenance or exchange of parts and then reassembled to be functioning properly. Typical components that experience wear are fastening or blocking plates, profile rollers or even eccentric shafts. Maintenance and exchange of parts in this manner are unfavorable from an economic point of view. Because this is also associated with a lengthy expenditure of time, this results in a correspondingly long machine downtime. The personnel performing the exchange must further be trained regularly in detail.
An exchange of components of a thread rolling head can also occur for other reasons. Thus, great demands for flexibility are placed on thread rolling heads during operation. Along with the rolling of metric standard threads, for example, custom threads with special pitch angles, teeth and a plurality of further profiles may also be rolled. In each case, at least the profile rollers must be exchanged, and frequently the eccentric shafts and distance bolts must also be exchanged. This also leads to the problems explained above.
It is thus desirable to provide a thread rolling head that can be used economically even in the case of wear or changed machining requirements.
A thread rolling head described herein has a bearing unit in which at least two profile rollers, and preferably at least three profile rollers, are rotatably mounted. It also has a shank section coupled to the bearing unit, wherein adjacent ones of the profile rollers delimit an insertion section into which a workpiece to be machined can be inserted. A bearing unit is built from at least two modules each forming a functional unit, wherein the modules each have fastening means, by which they can be connected together and can be exchanged for other modules also each forming a functional unit. One of the modules has fastening means for connecting to corresponding fastening means of a shank section.
The profile rollers between each other delimit an insertion section into which a workpiece to be machined can be inserted, in particular in the longitudinal direction. Thus, it can be an axial thread rolling head or a radial thread rolling head. It has at least two profile rollers, preferably three or more profile rollers. The profile rollers therebetween delimit an insertion section that is, for example, cylindrical or tapering cone-shaped in the direction of insertion of a workpiece. A shank section is conventionally coupled to the bearing unit. The thread rolling head can be fixed in a metal-cutting machine using the shank section. The shank section can be movable in the axial direction with respect to the bearing unit. The longitudinal axis of the insertion section can run, in particular, coaxial to the longitudinal axis of the shank section.
For inserting a workpiece, for example a cylindrical workpiece, into the insertion section in the axial direction, an axial relative movement is required between the workpiece and the thread rolling head. For this purpose, the workpiece or the thread rolling head, or both, can be moved in the axial direction. With an axial thread rolling head the machining, thus forming the thread, occurs in the course of inserting the workpiece into the insertion section. Thus, in this case, the cross-section of the insertion section in the machining position of the profile rollers is smaller, at least in sections, than the cross-section of the workpiece. With a radial thread rolling head, after the axial insertion of the workpiece into the insertion section, there is a radial positioning movement of the profile rollers onto the workpiece, and thereby the machining occurs. For the machining, the workpiece can be rotated, wherein the thread rolling head is arranged fixed against rotation. However, it is also possible that the workpiece is arranged fixed against rotation and the thread rolling head is rotated in the course of the machining.
The shank section can be axially movable with respect to the bearing unit, as explained. Then, the shank section in a first axial relative position can interact, using fastening means thereof, with corresponding fastening means of the bearing unit, whereby both parts are coupled together fixed against rotation. A gearing mechanism and a spring may be located between the shank section and eccentric shafts bearing the profile rollers in such a manner that in a second axial relative position of the shank section with respect to the bearing unit, in which the fastening means are disengaged, the spring is tensioned with a rotation of the bearing unit in a first direction of rotation with respect to the shank section or, respectively, the tensioned spring rotates the bearing unit relative to the shank section in the opposite, second direction of rotation. Also, a spring can tension the shank section and the bearing unit with respect to each other into the first relative position.
Mechanical switching means, for example, can contact the workpiece so as to bring the shank section and the bearing unit into the second relative position. In this manner, an opening and closing of the thread rolling head is possible by moving the profile rollers between the machining position thereof and a radially opened open position. In the open position, the cross-section of the insertion section is greater than the cross-section of the workpiece, such that the thread rolling head after machining can be removed from the workpiece without collision therewith. The profile rollers, in particular in the machining position thereof, may be uniformly distributed and arranged concentric to the insertion section. For example, three profile rollers may be so arranged. Naturally the longitudinal axes of the profile rollers can be slightly angled with respect to the longitudinal axis of the insertion section. The shank section along with the fastening means for connecting to the bearing unit can have further fastening means with which it can be fixed in a metal-cutting machine.
The bearing unit, which can be coupled to the shank section, is built from a plurality of modules which each form a functional unit according to an implementation of the invention. The modules are each composed of a plurality of components and preassembled into a unit, or respectively a module. They can be connected modularly together, or respectively to the shank section, and can be released again from each other, or respectively from the shank section, and thus can be exchanged for other such modules. For connecting the modules together, or respectively to the shank section, in a functionally secure manner, the modules each have suitable fastening means. During operation of the thread rolling head, torque can be transferred at least via several, in particular via all of the fastening means. The fastening means can provide, for example, a form-locking connection between the modules, or respectively to the shank section. The shank section can also be constructed modularly.
Due to the modular construction of the thread rolling head according to the teachings herein, the thread rolling head can be easily and economically repaired and maintained, as well as adapted to different operational requirements. For this purpose, it is desirable that only the fastening means serving as separation points between the modules, or respectively to the shank section, are loosened. Then, one or more modules each forming a functional unit can be exchanged for one or more other similar modules also forming a functional unit, in that the appropriate fastening means can be connected together again. Here, optionally-provided modules can also be inserted in a flexible manner in the thread rolling head, or can be removed therefrom. Here, in contrast to the documents explained above, it is not necessary to disassemble the entire thread rolling head, or the bearing unit thereof, into respective individual parts. The modules are exchanged easily and quickly. Undesired prolonged machine down times are avoided. Additionally, the customer using the thread rolling head can perform the exchange without problems, and without extensive knowledge of the assembly of the individual components. For this purpose, the fastening means are designed such that they each permit a functionally secure assembly allowing the function of the thread rolling head. For facilitating the assembly of the modules, fastening markings that display the correct assembly position can be provided on several or all modules.
The fastening means of at least two of the modules can provide a unique fastening position of these modules to each other. In some implementations, it is also possible that the fastening means of at least two of the modules provide exactly two fastening positions of these modules to each other. By allowing two fastening positions, a user can assemble the modules, depending on the respective fixing situation, to a metal-cutting machine. The assembly can be made such that a scale displaying a profile roller spacing, for example, is easily visible.
According to a further design, a first module of the bearing unit is a profile roller cage holding the profile rollers using fastening means. Optionally, a second module of the bearing unit is a spring housing with a spring arranged in the spring housing and with first and second fastening means, wherein the spring housing with the first fastening means thereof can be connected to fastening means of the shank section, and wherein the spring housing with the second fastening means thereof can be connected to the fastening means of the profile roller cage.
Modules provided with these designs each fulfill one function as a functional unit. The profile roller cage bears the profile rollers in a suitable manner. The spring housing supports a spring, for example a spiral spring, which can be pretensioned in the machining position of the profile rollers so that the spring, after releasing suitable mechanical or other switching means in the course of the tension release thereof, moves the profile rollers from the machining position into the open position. The displacement of the profile rollers between the machining position and the open position occurs, for example, by a rotation of the spring housing, and thus the bearing unit, relative to the shank section, caused by the spring. For movement of the profile rollers from the open position into the machining position, the bearing unit, for example, can be rotated with respect to the shank section in an appropriate manner such as manually against the pre-tensioning of the spring of the spring housing.
According to a further design, the shank section may also be constructed from at least two modules, wherein a first module is a closing unit having first and second fastening means, and wherein a second module is a shank having fastening means. The first fastening means of the closing unit can be connected to the fastening means of the shank, and the second fastening means of the closing unit provides fastening means with which the spring housing can be connected to the first fastening means. At least the closing unit likewise forms a functional unit built from a plurality of components. It is further possible that the fastening means of the shank and the second fastening means of the closing unit are identical in design. Then, the spring housing with the connected first fastening means can be selectively fastened to the closing unit, or if a closing unit is not required or desired, can be fastened directly to the shank.
The closing unit that can be connected to the spring housing serves to connect the bearing unit to the shank that can be fixed in a machine tool. Here it is possible that the shank section, formed from the closing unit and shank securely fastened thereto, is movable in the axial direction with respect to the bearing unit, thus in particular, also with respect to the spring housing and profile roller cage. For example, in a first axial relative position between the shank section and the bearing unit, rotation of the spring housing relative to the shank section due to the pretensioned spiral spring it can be prevented using a suitable dog clutch. In contrast, in a second relative axial position between the shank section and the bearing unit, which position results from releasing mechanical switching means, rotation of the shank section with respect to the bearing unit can be permitted, caused in particular by the pretensioning of the spring of the spring housing. The dog clutch can be released for this purpose. In such a design, the first and second fastening means of the spring housing may be axially movable together relative to the remaining components of the spring housing. The first fastening means of the spring housing, in the mounted position of the thread rolling head, can be securely connected to the assigned fastening means of the shank section such that, with an axial relative movement of the bearing unit with respect to the shank section, the first and second fastening means of the spring housing do not move with the bearing housing.
The thread rolling head may have a plurality of different profile roller cages and/or different spring housings and/or different closing units and/or different shanks, each designed as a module according to the teachings herein, which can be exchanged with each other in a suitable manner.
The profile roller cage can have a front plate and an intermediate plate, wherein the profile rollers, together with eccentric shafts bearing them rotatably, are held between the front plate and the intermediate plate. The profile roller cage can further have a plurality of distance bolts fastened to the front plate and extending between the front plate and the intermediate plate. The distance bolts, on the side facing away from the front plate, can each extend with an end section having external threads through the intermediate plate and the spring housing. Lock nuts can then be screwed onto the end sections from the side of the spring housing facing away from the profile roller cage. The distance bolts, on the opposite side thereof, can each be connected to the front plate using a screw connection. The distance bolts then form a part of the fastening means of the profile roller cage, and the lock nuts screwed onto the end sections of the distance bolts then form part of the second fastening means of the spring housing. Here, the distance bolts can extend through suitable arc-shaped elongated holes of the spring housing such that rotation is possible between the spring housing and the profile roller cage. During operation, this rotational movement can be prevented by suitable fastening means, for example, lock nuts screwed onto the distance bolts.
According to a further design, the fastening means of the profile roller cage may comprise a central ring gear, having external teeth, arranged on the intermediate plate on the side facing away from the front plate. The profile roller cage further includes a plurality of outer gears also on the intermediate plate on the side facing away from the front plate, meshing with the external teeth of the central ring gear, and the outer gears are each connected to one of the eccentric shafts, fixed against rotation. The outer gears can each be connected to one of the eccentric shafts, for example, in a form-locking or press fit manner. The center gear, as with the outer gears, can be mounted rotatably on the intermediate plate. A rotation of the center gear, caused for example by a rotation of the spring housing, then leads to a rotation of the outer gears and thus the eccentric shafts, and vice versa. Thereby, in turn, the spacing of the profile rollers to each other, and thus the cross-section of the insertion section, is displaced.
The second fastening means of the spring housing can further comprise a coupling section engaging in a form-locking manner in the ring gear of the profile roller cage. The coupling section of the spring housing can be designed as a toothed splined shaft, wherein the ring gear at the inner surface thereof can have a plurality of engagement grooves running in the axial direction of the thread rolling head, into which the splined shaft engages. Furthermore, the distribution of the splined shaft and the distribution of the engagement grooves formed on the inner surface of the ring gear may be non-uniform, such that the coupling section can engage precisely in one rotational position into the ring gear.
The first fastening means of the spring housing can have a coupling section, in particular a form-specific coupling section, and the second fastening means of the closing unit can comprise a likewise coupling section in form-locking engagement with the coupling section of the spring housing. It is also possible that the first fastening means of the closing unit has a coupling section, in particular a form-specific coupling section, and that the fastening means of the shank also has a likewise coupling section in form-locking engagement with the coupling section of the spring housing. With these designs, a form-locking, and thus fixed against rotation, fastening of the modules is possible in a particularly simple manner through which significant torques can also be transferred.
For precise adjustment of the spacing of the profile rollers in the machining position, the profile roller cage and the spring housing can be rotatable relative to each other by pre-tensioning, or respectively relaxing, the spring mounted in the spring housing and by changing the spacing of the profile rollers. The spring may be a spiral spring, and the change in spacing can be caused, in particular, by the gearing mechanism composed of center gear and outer gears described above.
According to a further design, the spring housing may have an annular groove running in a peripheral direction over the outer surface, in which an actuating clip is fastened with a catch so that rotation of the spring housing relative to the profile roller cage is possible via the actuating clip. The actuating clip can be placed in the annular groove and be securely fixed by screwing in a manner well known for clips. Then, using the actuating clip, the spring housing can be rotated relative to the profile roller cage. The catch in particular forms a stop for this purpose. According to a particularly practical design, the actuating clip can have an actuating section to which the catch is releasably fastened, for example by a standard screw connection. The catch can then be easily exchanged for another catch, or other components. By providing an actuating clip, the catch can be arranged in a flexible manner in any desired position of rotation on the spring housing. The thread rolling head can be manually closed again using the catch after the machining process.
These and other embodiments of the invention are explained in the following in more detail using the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views unless otherwise noted, and wherein:

FIG. 1 is a perspective, exploded view of a thread rolling head according to a first embodiment of the invention;

FIG. 2 is a first perspective view of a profile roller cage of the thread rolling head of FIG. 1;

FIG. 3 is a second perspective view of the profile roller cage of FIG. 2;

FIG. 4 is a first perspective view of a profile roller cage for a thread rolling head of FIG. 1 according to a second embodiment of the invention;

FIG. 5 is a second perspective view of the profile roller cage of FIG. 4;

FIG. 6 is a first perspective view of a profile roller cage for the thread rolling head of FIG. 1 according to a third embodiment of the invention;

FIG. 7 is a second perspective view of the profile roller cage of FIG. 6;

FIG. 8 is a first perspective view of a profile roller cage for the thread rolling head of FIG. 1 according to a fourth embodiment of the invention;

FIG. 9 is a second perspective view of the profile roller cage of FIG. 8;

FIG. 10 is a first perspective view of a spring housing of the thread rolling head of FIG. 1;

FIG. 11 is a second perspective view of the spring housing of FIG. 10;

FIG. 12 is a first perspective view of an actuating clip of the thread rolling head of FIG. 1;

FIG. 13 is a perspective view of the actuating clip of FIG. 12 in a second operating state;

FIG. 14 is a first perspective view of a closing unit of the thread rolling head of FIG. 1;

FIG. 15 is a second perspective view of the closing unit of FIG. 14;

FIG. 16 is a first perspective view of the closing unit for the thread rolling head of FIG. 1 according to a second embodiment;

FIG. 17 is a second perspective view of the closing unit of FIG. 16;

FIG. 18 is a perspective view of a shank of the thread rolling head of FIG. 1;

FIG. 19 is a perspective view of the shank for the thread rolling head of FIG. 1 according to a second embodiment; and

FIG. 20 is a perspective view of the shank for the thread rolling head of FIG. 1 according to a third embodiment.

DETAILED DESCRIPTION

A thread rolling head according to an embodiment of the invention shown in FIG. 1 has a shank 10 that has fastening means (not shown in detail) for fixing in a metal-cutting machine, for example. The shank 10 on one end has fastening means in the form of a coupling section 12. By means of this coupling section 12, the shank 10 can be connected releasably in a form-locking manner to a corresponding coupling section (not shown in FIG. 1) of a closing unit 16. The coupling sections, for example, can be additionally screwed together for the secure connection of shank 10 and closing unit 16. The shank 10 forms a first module and the closing unit 16 forms a second module of a modularly-designed shank section. The closing unit 16, on the side facing away from the shank 10, comprises second fastening means designed as a coupling section 18.
The thread rolling head further has a bearing unit 14, which is designed here comprising a plurality of modules each forming a functional unit. A first module of the bearing unit 14 is formed by a profile roller cage 36. A second module is formed by a spring housing 20 in which a spiral spring 22 is held, the outer end of which interacts with a slit within the spring housing 20. The spring housing 20 has first fastening means (not seen in FIG. 1) formed as a coupling section that can be connected in a form-locking manner to the coupling section 18 of the closing unit 16 so as to connect the spring housing 20 to the closing unit 16.
The spring housing 20, on the side facing away from the first fastening means, has second fastening means in the form of a coupling section formed as a toothed splined shaft 24. The spring housing 20 further has a ring-shaped annular groove 26, running over the periphery thereof, into which an actuating clip 28 can be inserted. The actuating clip 28 can be tensioned in the inserted state in the annular groove 26 using a screw connection 30, and thus be fastened to the spring housing 20. A catch 32, serving as a stop, is fastened to an actuating section of the actuating clip 28. Desirably, the fastening is releasable such as through the use of, for example, a standard screw connection. It can be further seen in FIG. 1 that the spring housing 20 on its inside faces away from the closing unit 16 and in the example shown has three arc-shaped elongated holes 34.
The profile roller cage 36 has an intermediate plate 38 and a front plate 40. In the example shown, between the intermediate plate 38 and the front plate 40, three eccentric shafts 42 are arranged, each of which rotatably mounts a profile roller (not shown in FIG. 1). The front plate 40 and the intermediate plate 38 are held apart, in the example shown, using three distance bolts 44. The distance bolts 44 are each screwed to the front plate 40 using a screw connection 46. Each distance bolt 44 has an end section 48 with external thread on the end facing away from the front plate 40. The end sections 48 extend through the intermediate plate 38 and the spring housing 20 and are each guided through an elongated hole 34 of the spring housing 20. The intermediate plate 38 has fastening means (not shown in FIG. 1) on the side facing away from the front plate 40 into which the splined shaft 24 of the spring housing 20 engages in a form-locking manner. In the assembled state, the profile rollers of the profile roller cage 36 between each other delimit an insertion section 50, into which a workpiece to be machined can be inserted in the longitudinal direction.
FIGS. 2 and 3 show the profile roller cage 36 of the thread rolling head of FIG. 1 in more detail. In particular, the fastening means of the profile roller cage 36 for fastening to the spring housing 20 can be seen. The fastening means comprise, along with the distance bolts 44 and the end sections 48 thereof, a ring gear 52 having a plurality of engagement grooves 54 running along the axial direction on its inner surface. The splined shaft 24 of the spring housing 20, in the assembled state, engages in the engagement grooves 54 of the ring gear 52. It can be further seen in FIG. 3 that three outer gears 56 mesh with the ring gear 52 in the illustrated example. The outer gears 56 are each connected in a form-locking manner to one of the eccentric shafts 42. A relative rotation, for example between the spring housing 20 and the profile roller cage 36, leads to a rotation of the outer gears 56 and thus the eccentric shafts 42 bearing the profile rollers, by means of the form-locking engagement of the splined shaft 24 in the engagement grooves 54 of the ring gear 52. This in turn leads to a change of the spacing of the profile rollers to each other, and thus a change of the cross-section of the insertion section 50. For this purpose, the ring gear 52 is mounted rotatably on the intermediate plate 38 of the profile roller cage 36.
If the splined shaft 24 of the spring housing 20 and the ring gear 52 of the profile roller cage 36 are engaged, the profile rollers have a predefined spacing to each other, namely in a machining position. The spiral spring 22 is tensioned in this machining position. If a thread is formed in a workpiece that is inserted into the insertion section 50 formed between the profile rollers, the workpiece moves rotatingly into the thread rolling head, or respectively the bearing unit 14, until the feed motion is terminated by a stop (not shown), and the bearing unit 14 itself is further moved due to the described feed motion. The bearing unit 14 composed of the profile roller cage 36 and the spring housing 20 moves axially relative to the shank section composed of the shank 10 and the closing unit 16.
The splined shaft 24 and the coupling section 60 formed on the opposite side of the spring housing 20 (see FIG. 11), which together form the first fastening means of the spring housing 20, are formed here on a common part, which is movable axially relative to the remaining components of the spring housing 20. The coupling section 60 is securely screwed to the coupling section 18 of the closing unit 16 such that the part composed of splined shaft 24 and coupling section 60 do not move with the bearing unit. The splined shaft 24 however remains engaged with the ring gear 52 of the spring housing 20 (see FIG. 3). In the course of this axial relative movement, claws of a dog clutch (not shown in FIG. 1) become disengaged, and due to the spring effect of the spiral spring 22 there is a relative rotation between the bearing unit 14 and the shank section 10, 16, wherein this rotation can occur only over a predefined angle of rotation due to the formation of the dog clutch. This relative rotation causes a rotation of the eccentric shafts 42 such that the profile rollers move into the open position and the thread rolling head is opened. Here, the splined shaft 24 and thus the ring gear 52 do not rotate. However, because the end sections 48 of the distance bolts 44 are securely screwed to the spring housing using screw nuts 62 (see FIG. 11), the outer gears 56 meshing with the ring wheel 52 rotate such that there is a displacement of the profile rollers. The workpiece can now be removed from the thread rolling head.
If the thread rolling head is to be closed again, the bearing unit 14 of the spring housing 20, together with the closing clip 28 and the profile roller cage 36, must be rotated in the opposite direction until the dog clutch re-engages. Because the bearing unit 14 with the described opening movement was removed axially from the closing unit 16 with the shank 10, a tensile force was also exerted on the spiral spring 22. The dog clutch is reengaged using the thusly generated pre-tensioning. Thus, the profile rollers are again located in the machining position thereof, and the thread rolling head is closed for a new machining process.
FIGS. 4 and 5 show a second exemplary embodiment of a profile rolling cage 36′. This corresponds largely with the profile roller cage 36 shown in FIGS. 2 and 3. It can be inserted into the thread rolling head of FIG. 1 instead of the profile roller cage 36 shown in FIGS. 2 and 3. In contrast to the profile roller cage 36 shown in FIGS. 2 and 3, with the profile roller cage 36′ of FIGS. 4 and 5, the distance bolts 44′ are designed such that the profile roller cage 36′ is partially closed over the periphery thereof. This is desirable for some applications.
Likewise, it is also possible to insert the profile roller head 36″ shown in FIGS. 6 and 7 into the thread rolling head of FIG. 1, instead of the profile roller cage 36 shown in FIGS. 2 and 3. This profile roller cage 36″ again corresponds largely to the profile roller cage 36 shown in FIGS. 2 and 3. However, in contrast to the embodiment of FIGS. 6 and 7, the distance bolts 44″ and thus also the eccentric shafts 42″ are designed longer such that longer threads can be formed due to an enlarged section between the front plate 40 and the intermediate plate 38.
It is also possible, for example, to replace the profile roller cage 36 shown in FIGS. 2 and 3 by a profile roller cage having a changed angular arrangement of the eccentric shafts 42, in order to form a custom angle for example.
FIGS. 8 and 9 show a further example of an embodiment of a profile roller cage 36′″ that can be used as a module with the thread rolling head of FIG. 1. Again, the profile roller cage 36′″ corresponds largely to the profile roller cage 36 shown in FIGS. 2 and 3. In contrast, in this exemplary embodiment, the distance bolts 44′″ together with the wall section 58 are constructed such that a closed profile roller cage 36′″ is formed.
FIGS. 10 and 11 show the spring housing 20 of the thread rolling head of FIG. 1 in more detail. The view in FIG. 11 shows the first fastening means of the spring housing 20 formed as a coupling section 60 that is assembled by screwing the spring housing 20 in the coupling section 18 of the closing unit 16. FIG. 11 further shows three screw nuts 62 that are screwed onto the end sections 48 of the distance bolts 44 for fastening the profile roller cage 36 to the spring housing 20. They form a part of the second fastening means of the spring housing 20.
FIGS. 10 and 11 further show a precise adjustment possibility for adapting the spacing of the profile rollers to each other in the machining position. The precise adjustment comprises a slide block 66 with a thread, guided on a threaded pin 64. The threaded pin 64 is securely mounted axially and rotatably in the spring housing 20. Rotation of the threaded pin 64 leads to axial movement of the slide block 66. The slide block 66 has an elongated hole 68 running in a radial direction into which, in the example shown, one of the end sections 48 of the distance bolts 44 is guided for radial movement. Forward or backward axial movement of the slide block 66 leads therefore to a relative rotation between the spring housing 20 and the profile roller cage 36, and thus to rotation of the eccentric shafts via the above-described mechanisms of the ring gear 52 and the outer gears 56, and thus to an adjustment of the spacing of the profile rollers to each other. A scale 70 is shown on the outside of the spring housing 20 that displays the precise adjustment of the spacing of the profile rollers to each other. It is understood in this design that the screw nuts 62 must be loosened first for the precise adjustment.
FIGS. 12 and 13 are enlarged views of the actuating clip 28. In FIG. 13, the catch 32 is not shown for reasons of clarity. The catch 32 or other catches or components can be screwed into a screw thread shown with reference number 72.
FIGS. 14 and 15 are enlarged views of the closing unit 16 of the thread rolling head of FIG. 1. Along with the coupling section 18 for connecting to the spring housing 20, FIG. 15 also shows the coupling section 74, which engages in a form-locking manner in the corresponding coupling section 12 of the shank 10. In this example, the engagement is a screw engagement. A closing lever guided in an arc shaped elongated hole can be seen at reference number 76. FIGS. 16 and 17 illustrate a further embodiment of a closing unit 16′, which in this case is driven electronically and thus has no closing lever. However, the remainder of the closing unit 16′ corresponds to that shown in FIGS. 14 and 15. As seen in FIGS. 14 to 17, the coupling sections 18, 74 each allow an assembly of the closing units 16, 16′ to the spring housing 20, or respectively the shank 10, in exactly two positions of rotation. This design allows the user, depending on the concrete installation position, to arrange the components of the thread rolling head such that a scale, for example for the precise adjustment of the spacing of the profile rollers, can easily be viewed. It can be further seen that the coupling sections 12 and 18 of the shank 10 and the closing unit 16, 16′ are identical in design.
FIG. 18 is an enlarged view of the shank 10 of the thread rolling head of FIG. 1. FIG. 19 is another example of the shank 10′ that can be used with the thread rolling head of FIG. 1. The shank 10′ may be a so-called VDI shank according to DIN 69880 for fixing in a metal-cutting machine. In contrast to the round shank 10 from FIG. 18, the shank 10′ from FIG. 19 is not rotationally symmetric. Again, the shank 10′ has fastening means, only partially visible, in the form of a coupling section 12 for connecting to the closing unit 16. FIG. 20 shows a further example of a shank 10″ that can be used with the thread rolling head of FIG. 1. This shank 10″ in FIG. 20 also has a fastening means, only partially visible, in the form of a coupling section 12 for connecting to the closing unit 16. The shank 10″ shown in FIG. 20 is a so-called hollow shank taper (HSK) according to DIN 69893 for accommodation in tool machines. This shank 10″ is also not rotationally symmetric. The catch 32, serving as a stop, can be variably positioned on the periphery of the thread rolling head due to the actuating clip 28, especially with the use of non-rotationally symmetric shanks.

Claims

What is claimed is:

1. A thread rolling head, comprising:

a bearing unit in which at least two profile rollers are rotatably mounted; and

a shank section coupled to the bearing unit; wherein:

adjacent ones of the at least two profile rollers delimit an insertion section into which a workpiece to be machined can be inserted;

the bearing unit is built from at least two modules, each module forming a functional unit and having a module fastening device through which they can be connected together;

each module can be exchanged for other modules also each forming a functional unit; and

one of the at least two modules includes a fastener for connecting to a corresponding fastener of the shank section.

2. The thread rolling head according to claim 1, wherein the module fastening devices of adjacent modules of the at least two modules define a unique fastening position of the adjacent modules to each other.

3. The thread rolling head according to claim 1, wherein the module fastening devices of adjacent modules of the at least two modules define exactly two fastening positions of the adjacent modules to each other.

4. The thread rolling head according to claim 1, wherein:

a first module of the bearing unit is a profile roller cage holding the at least two profile rollers;

a second module of the bearing unit is a spring housing having a spring arranged in the spring housing, the fastener being a first connector of the spring housing connecting the spring housing to the shank section and the module fastening device of the second module being a second connector of the spring housing connecting the spring housing to the module fastening device of the profile roller cage.

5. The thread rolling head according to claim 4, wherein:

the shank section is built from at least two modules;

a first module of the shank section is a closing unit having a first closing unit fastening device and a second closing unit fastening device;

a second module is a shank having a shank fastening device;

the first closing unit fastening device is connected to the shank fastening device; and

the second closing unit fastening device is connected to the first connector of the spring housing.

6. The thread rolling head according to claim 4, wherein:

the profile roller cage has a front plate and an intermediate plate; and

the at least two profile rollers are held together with eccentric shafts rotatably bearing the at least two profile rollers between the front plate and the intermediate plate.

7. The thread rolling head according to claim 6, wherein the profile roller cage has a plurality of distance bolts fastened to the front plate and extending between the front plate and the intermediate plate.

8. The thread rolling head according to claim 6, wherein:

the module fastening device of the profile roller cage comprises a central ring gear with external teeth arranged on the intermediate plate on a side facing away from the front plate;

the profile roller cage comprises a plurality of outer gears meshing with the external teeth of the central ring gear, arranged also on the intermediate plate on the side facing away from the front plate; and

each of the plurality of outer gears is connected so as to be fixed against rotation to one of the eccentric shafts.

9. The thread rolling head according to claim 8, wherein the second connector of the spring housing comprises a coupling section engaging in a form-locking manner in the central ring gear of the profile roller cage.

10. The thread rolling head according to claim 9, wherein:

the coupling section is formed as a splined shaft;

the central ring gear on an inner surface thereof has a plurality of engaging grooves running in an axial direction of the thread rolling head; and

and the splined shaft engages into the plurality of engaging grooves.

11. The thread rolling head according to claim 10, wherein a division of the splined shaft and a division of the plurality of engaging grooves are non-uniform such that the coupling section can engage in the central ring gear in precisely one position of rotation.

12. The thread rolling head according to claim 5, wherein:

the first connector of the spring housing has a coupling section;

the second closing unit fastening device comprises a coupling section in form-locking engagement with the coupling section of the spring housing.

13. The thread rolling head according to claim 5, wherein:

the first closing unit fastening device has a coupling section; and

the fastener of the shank comprises a coupling section in form-locking engagement with the coupling section.

14. The thread rolling head according to claim 4, wherein the profile roller cage and the spring housing are rotatable relative to each other with pre-tensioning or relaxing of the spring mounted in the spring housing and with changing of spacing of the profile rollers.

15. The thread rolling head according to claim 14, wherein:

the spring housing has an annular groove running in a peripheral direction about an outer surface; and

an actuating clip with a catch is fastened within the annular groove such that rotation of the spring housing relative to the profile roller cage is possible using the actuating clip.

16. The thread rolling head according to claim 15, wherein the actuating clip has an actuating section to which the catch is releasably fastened.