The disclosure relates to a die stock and to a holder and a cutting insert for such a die stock.
Die stocks, often also referred to as screw dies, are frequently used for machining of external threads and are known in various designs. In one design, die stocks are constructed in one piece as a HSS (High Speed Steel) tool. Although these are inexpensive to manufacture, they are limited in terms of performance and are uneconomical due to low cutting data. Furthermore, if a cutting edge is damaged, the entire die stock has to be exchanged. Die stocks which are made completely of hard metal as a one-piece tool are also known. These offer better performance, but are very expensive and complex in terms of manufacture. In addition thereto, die stocks with cutting inserts are known. However, due to the installation space conditions, these have less cutting inserts than the above-stated HSS die stocks and hard metal die stocks. Moreover, because of the space which is necessary for the insertion of the cutting inserts, they offer unfavorable stability of the tool.
It is therefore an object to provide a die stock which overcomes the above-mentioned disadvantages.
In view of this object, there is provided a die stock comprising: an annular holder having a plurality of receiving grooves, a plurality of cutting inserts, and one fixture per cutting insert for axially fixing the respective cutting insert in one of the plurality of receiving grooves. The receiving grooves are provided on an inner periphery of the annular holder and run in an axial direction parallel to a central longitudinal axis of the annular holder. Each of the plurality of receiving grooves has a receiving groove profile for receiving one of the plurality of cutting inserts. Each cutting insert is received within a respective one of the receiving grooves and comprises at least one cutting edge that is arranged on a cutting surface that faces toward the central longitudinal axis of the annular holder. Each cutting insert further comprises a holding profile that is arranged on a holding surface opposite the cutting surface. The receiving groove profiles of the receiving grooves and the holding profiles of the cutting inserts interact with each other in such a way that a cutting insert, when inserted into its receiving groove, is guided in the axial direction parallel to the central longitudinal axis of the annular holder and, in the fully inserted state, is clamped in a radial direction perpendicular to the central longitudinal axis of the annular holder.
According to a further aspect, there is provided a holder for a die stock, which holder is of annular design and comprises a plurality of receiving grooves that are provided on an inner periphery of the annular holder and run in an axial direction parallel to a central longitudinal axis of the annular holder, wherein each of the plurality of receiving grooves has a receiving groove profile for receiving a cutting insert that has on a cutting surface directed toward the central longitudinal axis of the annular holder at least one cutting edge and on an opposite holding surface a holding profile. The receiving groove profile of each receiving groove interacts with the holding profile of the cutting inserts in such a way that the cutting insert, when inserted into its receiving groove, is guided in the axial direction and, in the fully inserted state, is clamped in the radial direction and fixed in the axial direction by means of a fixture.
According to a still further aspect, there is provided a cutting insert for a die stock, wherein the die stock has an annular holder having a plurality of receiving grooves which are provided on an inner periphery and run in an axial direction parallel to a central longitudinal axis of the annular holder, wherein each of the plurality of receiving grooves has a receiving groove profile for receiving the cutting insert, and wherein the die stock has one fixture per cutting insert in order to axially fix the cutting insert in the receiving groove. The cutting insert comprises on a cutting surface directed toward the central longitudinal axis of the annular holder at least one cutting edge, and has on an holding surface opposite the cutting surface a holding profile. The receiving groove profile of the receiving grooves and the holding profile of the cutting inserts interact with each other in such a way that the cutting insert, when inserted into its receiving groove, is guided in the axial direction, and, in the fully inserted state, is clamped in a radial direction perpendicular to the axial direction.
In the provided die stock, good stability is achieved by the cutting inserts being guided and held in a ring. Preferably, the annular holder is here made of HSS or other steel, while the cutting inserts are formed of hard metal. The cutting inserts are seated in corresponding receiving grooves provided on the inner periphery of the holder. The guidance and holding of the cutting inserts in the respective receiving grooves of the holder can be realized differently, wherein it is respectively ensured that an axial guidance of the cutting insert when inserted into its receiving groove is effected and wherein, following the insertion, the cutting insert is radially clamped in order to achieve exact positioning and thus high machining accuracy.
In the provided die stock, the cutting inserts are thus introduced from an end face of the holder in the axial direction, i.e. parallel to the holder longitudinal axis, into the corresponding receiving grooves and are not, as in known die stocks, designed via a ring as a one-piece element. Nor are they fitted in the radial direction from the inner side of the holder onto the holder or pillar-shaped holding elements. In comparison to known die stocks having changeable cutting inserts, more cutting inserts can hence be fitted onto the holder, whilst the spatial requirement remains the same.
All in all, the provided die stock, the provided holder and the provided cutting insert combine the advantages of the different designs of known die stocks. Since the holder per se can basically be made of simple steel, the manufacturing costs are significantly less than a one-piece die stock which is made entirely of hard metal. If a cutting insert is damaged, it is sufficient to exchange just this individual cutting insert, which, in the case of the provided die stock, is also easily possible without the holder having to be partially dismantled and/or other cutting inserts having to be removed or even exchanged. In addition, the provided die stock offers high machining accuracy and good stability.
It is preferably provided that the cutting inserts are of identical design. This leads to a further cost reduction, since different types of cutting inserts do not have to be made and provided to the user. Since, in such a case, for the use of the die stock for thread cutting, the cutting inserts can in principle not be identically positioned in the axial direction, further preferably axial positioning means are provided for the axial positioning of the cutting inserts in the respective receiving groove. Such axial positioning means can be, for example, spacer elements, which can be placed into the receiving grooves prior to the insertion of the respective cutting insert. These spacer elements can either be fixedly attached to the holder or be changeable, so that the axial positioning of the individual cutting inserts can also be varied, for example if cutting inserts are exchanged in order, for instance, to produce a thread with different pitch or with a different number of thread turns.
In a refinement, the holder comprises: a first holding ring, on which the receiving grooves are provided as continuous grooves, and a second holding ring, which is detachably connected to the first holding ring and which on its end face facing the first holding ring has as axial positioning means receiving recesses, which, in terms of number and positions, correspond with the number and the positions of the receiving grooves of the first holding ring and which are provided for the support and positioning, in the axial direction, of the respective cutting insert inserted in its receiving groove.
In this refinement, the axial positioning of the individual cutting inserts is thus determined by the depth of the receiving recesses in the second holding ring, though it is also conceivable that corresponding spacer elements can, if necessary, additionally be placed into these receiving recesses.
Alternatively, in another refinement it is provided that the holder is designed as a one-piece holding ring and that the axial length of the receiving grooves is designed differently for the desired axial positioning of the cutting inserts. This makes for a higher production complexity, however. In this solution also, corresponding spacer elements can, if necessary, be inserted into the receiving grooves.
Although it is advantageous that the cutting inserts are of identical design, it is alternatively also conceivable that the axial positioning of the cutting inserts is determined by the respective length of the cutting inserts in the axial direction, in which case the receiving grooves preferably have an identical axial length. Of course, also in this refinement of the cutting inserts, the receiving grooves can be designed differently long, or the holder can be designed in two parts, as described above, comprising a first holding ring and a second holding ring. Furthermore, spacer elements can here too additionally be used.
In a further refinement, it is provided that on the end face of the holder, from which the cutting inserts are introduced into the respective receiving groove, there is arranged for each receiving groove one fastening recess, which in the radial direction opens out into the receiving groove and which in the axial direction is adjoined by a threaded bore for the reception of a respective clamping screw for the axial clamping of the respective cutting insert in the receiving groove. On the one hand, an axial clamping of the cutting insert in the respective receiving groove is thereby achieved. In addition, it can thereby be achieved that over the end face of the holder, from which the cutting inserts are introduced into the respective receiving groove, there protrude no holding or clamping elements for fixing of the cutting inserts, so that the die stock can machine cut up to the facing stop imposed by the end face of the holder. Preferably, the fastening recesses are namely designed such that the fixture, inclusive of clamping screw, are received therein and, as far as possible, form with the end face of the holder a plane surface, or at least do not protrude beyond this.
Advantageously, it is further provided that the cutting inserts, in that region of the holding surface which in the inserted state is touched for fixing purposes by the respective fixture, has a projection in which the fixture engages. Both a secure axial and a secure radial clamping of the cutting insert can thereby be effected.
In addition, it is here preferably provided that the fixture has per cutting insert a clamping screw and a clamping plate acting on the cutting insert, wherein the clamping plate and that clamping surface of the projection on which this acts, run in the same way obliquely to the holder longitudinal axis, so that the cutting insert, when fixed by the fixture, is pulled in the radial direction into the receiving groove. Such a refinement helps to further increase the radial and axial fixing of the cutting insert in its receiving groove.
In one refinement, it is provided that that contact surface of the cutting insert which in the inserted state of a cutting insert is supported against a supporting surface of the holder, and the supporting surface of the holder, run in the same way obliquely to the holder longitudinal axis, so that the cutting insert, when fixed by the fixture, is pulled in the radial direction into the receiving groove. This measure, too, further helps to fix the cutting insert as tightly as possible in the receiving groove.
In principle, the guidance and fixing can be realized differently. In another refinement, it is provided by way of example that the receiving groove profile and the holding profile have a (in particular wedge-shaped) cross section, which becomes increasingly narrow with increasing distance from the holder longitudinal axis. Inversely configured wedge shapes or cylindrical cross-sectional shapes are also, however, usable in principle. In other refinements, it is provided that the receiving groove profile and the holding profile have a cross-sectional profile, which profiles interact with each other in the manner of a rail, a tongue and groove or a toothing.
The number of cutting edges on the cutting inserts can be chosen according to the purpose of use. In many applications, one cutting edge per cutting insert is sufficient. In the thread cutting, cutting inserts having a multiplicity of cutting edges are frequently used, however. The cutting edges themselves can all be of identical design, but can also be of different design, in order to achieve the desired metal cutting effect in successive work steps by virtue of the different cutting edges.
It shall be noted that the features which are mentioned above and those which have yet to be explained below are usable not only in the respectively stated combination, but also in different combinations or on their own without departing from the scope of the present disclosure.
Further features and advantages of the disclosure emerge from the description below of a plurality of preferred exemplary embodiments with reference to the drawings, in which:
On that longitudinal side of the cutting inserts 3 which lies opposite the holding profile 30, 31 is respectively provided a cutting surface 32, which cutting surfaces have at least one cutting edge 33, in the present case a multiplicity of cutting edges. In the assembled die stock 1, as shown in
In order to axially fix the respective cutting insert 3, by the end face, in the associated receiving groove 24 of the holder, suitable holding means 5 (also denoted as fixture 5) are provided. These holding means 5 are formed in the shown embodiment by a clamping plate 51 and a clamping screw 52. The clamping plate 51 has a central bore, through which the clamping screw 52 can be screwed into an internally threaded bore 25 running in the z direction on the first holding ring 21. In the upper end face 26 of the first holding ring 21 are provided, for the reception of the clamping plate 51, corresponding fastening recesses 27, which respectively in the radial direction open out into the receiving groove 24 and in the floor of which is drilled said threaded bore 25.
As can be seen, in particular, from
From
In the shown illustrative embodiment, furthermore, on the outer periphery of the second holding ring 71 are provided a plurality of holding bores 75, by means of which the die stock can be secured in a die stock holder (not shown), a machine tool, or otherwise.
For this positioning, the receiving recesses 74 can be drilled, for example, to different depth into the second holding ring 71, viewed from its upper end face 76. Alternatively or additionally, corresponding spacer elements 77 (such a spacer element is indicated in
On the floor of the receiving recess can be arranged a flat supporting surface, or one or two (as shown in
Alternatively, various second holding rings 71 having differently deep receiving recesses 74 can instead be provided, which second holding rings then thus bring about a changed axial positioning of the cutting inserts 3. In such a case, the user can then, in addition to a single first holding ring 21, be provided with a set of differently designed second holding rings 71 and different sets of cutting inserts 3 if this die stock is intended to be used to make different threads. Of course, it is also respectively conceivable in this context that the cutting inserts 3 can reach differently far into the interior of the die stock in order to machine different workpieces.
Alternatively, it is also, of course, conceivable that just a single second holding ring 71 having receiving recesses 74 of equal depth is provided, and that the axial positioning of the various cutting inserts is provided by cutting inserts of different length, so that the respective length of the individual cutting inserts thus determines their axial position.
However, it is also, of course, conceivable to use other cross-sectional profiles for the receiving groove profile and the holding profile, for example cross-sectional profiles which interact with each other in the manner of a rail, a tongue and groove or a toothing and bring about the axial guidance of the cutting insert 3 in its receiving groove 24. The cross-sectional profiles can here also be designed such that, even without fastening of the cutting insert by means of holding means, the cutting insert, when introduced, can no longer fall radially out of the receiving groove.
As can be seen, in particular, from
In addition, it can be seen, in particular, from
Self-evidently, the present invention is not limited to the illustrative embodiment shown in the figures and explained above. Numerous variants are conceivable without departing from the scope of the present invention. The shown and described individual features can also respectively be mutually combined in other combinations. In particular, the number and basic design of the cutting inserts plays no significant role for the present invention. According to the purpose of use, these can be chosen correspondingly.
The provided die stock enables a simple and rapid exchange of individual or all cutting inserts. The cutting inserts are respectively reliably guided and positioned both in the axial and in the radial direction, whereby a desired high machining accuracy is achieved. In addition, preferably only the cutting inserts are produced from hard metal, while the holder itself can be made from less expensive steel.
Aspects of the invention may be described in the general context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with a variety of computer-system configurations, including multiprocessor systems, microprocessor-based or programmable-consumer electronics, minicomputers, mainframe computers, and the like. Any number of computer-systems and computer networks are acceptable for use with the present invention.
Specific hardware devices, programming languages, components, processes, protocols, and numerous details including operating environments and the like are set forth to provide a thorough understanding of the present invention. In other instances, structures, devices, and processes are shown in block-diagram form, rather than in detail, to avoid obscuring the present invention. But an ordinary-skilled artisan would understand that the present invention may be practiced without these specific details. Computer systems, servers, work stations, and other machines may be connected to one another across a communication medium including, for example, a network or networks.
As one skilled in the art will appreciate, embodiments of the present invention may be embodied as, among other things: a method, system, or computer-program product. Accordingly, the embodiments may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware. In an embodiment, the present invention takes the form of a computer-program product that includes computer-useable instructions embodied on one or more computer-readable media.
Computer-readable media include both volatile and nonvolatile media, transitory and non-transitory, transient and non-transient media, removable and nonremovable media, and contemplate media readable by a database, a switch, and various other network devices. By way of example, and not limitation, computer-readable media comprise media implemented in any method or technology for storing information. Examples of stored information include computer-useable instructions, data structures, program modules, and other data representations. Media examples include, but are not limited to, information-delivery media, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD), holographic media or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage, and other magnetic storage devices. These technologies can store data momentarily, temporarily, or permanently.
The invention may be practiced in distributed-computing environments where tasks are performed by remote-processing devices that are linked through a communications network. In a distributed-computing environment, program modules may be located in both local and remote computer-storage media including memory storage devices. The computer-useable instructions form an interface to allow a computer to react according to a source of input. The instructions cooperate with other code segments to initiate a variety of tasks in response to data received in conjunction with the source of the received data.
The present invention may be practiced in a network environment such as a communications network. Such networks are widely used to connect various types of network elements, such as routers, servers, gateways, and so forth. Further, the invention may be practiced in a multi-network environment having various, connected public and/or private networks.
Communication between network elements may be wireless or wireline (wired). As will be appreciated by those skilled in the art, communication networks may take several different forms and may use several different communication protocols. And the present invention is not limited by the forms and communication protocols described herein.
All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.
Number | Date | Country | Kind |
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10 2011 013 789.0 | Mar 2011 | DE | national |
The present application is a continuation of international patent application Serial No. PCT/EP2012/053468, filed Feb. 29, 2012, which claims the benefit of German Patent Application Serial No. 10 2011 013 789.0, filed on Mar. 2, 2011, both of which are hereby incorporated by reference herein in their entirety, including any figures, tables, or drawings.
Number | Date | Country | |
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Parent | PCT/EP2012/053468 | Feb 2012 | US |
Child | 14015337 | US |