SYSTEM CONSISTING OF A TOOL HOLDER AND A TOOL WITH A PULL-OUT LOCK

Description

[0001] The present invention relates to tool holders with a tool holder, in particular shrink fit chucks and other chucks for holding rotary tools according to the preamble of claim 1.

[0002] Tool holders with chucks, especially shrink-fit chucks, are widely known. They are used for clamping pipe, turning, milling, reaming, and grinding tools, etc., through a thermally induced shrinking process. Such shrink-fit chucks are typically thermally heated by an inductive shrink-fit system, which increases the inner diameter of the shrink-fit chuck. With the inner diameter enlarged, a tool to be clamped is inserted into the shrink-fit chuck. The ratio of the inner diameter of the shrink-fit chuck to the tool shank diameter is designed such that the tool is clamped to the shrink-fit chuck in a torque-resistant manner when the shrink-fit chuck subsequently cools.

[0003] From WO 01 / 89758 A1, it is known to inductively heat the sleeve section by means of an annular coil arrangement that surrounds the sleeve section essentially coaxially. The coil arrangement is connected to a high-frequency alternating current generator and induces eddy currents in the metallic sleeve section, which heat the sleeve section. To prevent stray flux and to concentrate the magnetic flux, magnetic flux concentrator elements made of a soft magnetic, electrically essentially non-conductive material, such as ferrite or the like, are arranged on the end faces and outer circumference of the coil arrangement. These elements direct the magnetic flux generated by the coil arrangement onto the sleeve section of the tool holder, and in particular into the region of the free end of the sleeve section.

[0004] The problem with tool holders with chucks for rotary tools that have a cylindrical shank is the axial displacement of the rotary tool along the chuck's rotational axis during operation. This axial displacement of the rotary tool is caused by vibrations that occur while machining the workpiece with the rotary tool. Due to this adverse effect, the workpieces can no longer be machined precisely and to their correct dimensions. Furthermore, jamming of the rotary tool in the workpiece or even in the chuck holding the workpiece could lead to dangerous accidents. Under unfavorable conditions, the rotary tool could even leave the tool holder's chuck during operation, posing a serious hazard to the machine operator.

[0005] JP 2002 355727 A shows a system comprising a tool holder and a tool according to the preamble of claim 1.

[0006] The object of the present invention is therefore to provide a tool holder with a chuck, in particular a shrink fit chuck or the like, in which axial migration of the rotary tool, such as round drills, profile drills, screw drills including taps, countersinks, milling cutters, etc., is not possible during operation, but the rotary tool is held both torque-resistant and axially with respect to the axis of rotation without migration.

[0007] This object is achieved according to the invention by the characterizing features of claim 1, wherein expedient further developments of the invention are created by the features in the subclaims.

[0008] According to the invention, a tool holder according to the invention has a pull-out protection device for the tool, which prevents the tool from axially moving out of the tool holder. The pull-out protection device comprises at least one locking element and at least one locking groove corresponding thereto and receiving the locking element, which cooperate in a form-fitting manner. The locking element and the locking groove are designed at least partially like a spherical head, with either the chuck having the locking elements and the tool having the locking groove, or vice versa. Furthermore, the locking grooves, which are located either on the front side of the tool shank or in the tool holder, can be designed with an expanded groove width in order to enable easier insertion of the tool in the tool holder.

[0009] In a particularly preferred embodiment, the tool holder has at least two rotatably mounted balls on the tool holder side, with at least two locking grooves on the rotary tool shank corresponding to the balls interacting in a form-fitting manner on the rotary tool side. The two locking grooves are preferably arranged in a thread-like manner on the cylindrical tool shank, starting at the end face of the cylindrical shank along the circumferential surface of the cylindrical shank. These locking grooves, located on the circumferential surface of the cylindrical shank of the rotary tool, are arranged to the left for left-handed tools and to the right for right-handed rotary tools. The locking grooves can also be formed axially and thus parallel to the axis of rotation, which still acts as an anti-twist device for the tool.

[0010] To clamp the rotary tool according to the invention, such as round drills, profile drills, screw drills including taps, countersinks, milling cutters, mandrels for other tools, etc., into the chuck according to the invention, e.g. shrink fit chuck of the tool holder, the induction coil in the shrink fit chuck is first switched on, i.e. the induction coil is subjected to high-frequency alternating current. Due to the eddy currents occurring in the sleeve section of the tool holder, generated by induction from the coil surrounding the tool holder, the sleeve section is quickly heated so that it expands thermally and the inside diameter of the receiving opening is increased. The rotary tool can now be inserted into the receiving opening on the shank side. The end face of the rotary tool comes into contact with the balls projecting into the interior of the receiving opening and strikes there.Depending on the pitch of the locking groove on the rotary tool, it is now rotated counterclockwise or clockwise relative to the axis of rotation so that the balls can engage in the spherical grooves. Further rotation forces a helical screwing and thus an axial retraction movement of the rotary tool into the shrink fit chuck or similar until the end face of the cylindrical shank hits the chuck or until the balls in the spherical locking grooves have reached their end position. The induction coil can now be switched off. Due to the rapid cooling that now begins, the shrink fit chuck shrinks back to its original size, whereby the cylindrical shank is torque-tightly connected with its peripheral surface to the inner peripheral surface of the receiving opening of the shrink fit chuck with a press fit.Because the direction of rotation of the locking grooves corresponds to the direction of rotation of the rotary tools, axial migration of the rotary tool along the axis of rotation can no longer occur during operation of the tool, even under heavy loads, i.e. when the workpiece has a high cutting strength and the tool or tool table is advanced at high speeds. The interaction of the balls in the tool holder with the spherical profile-shaped locking grooves in the tool shank and the thread-like design of these locking grooves creates an axial locking. This axial locking can only be released by rotating the rotary tool in the opposite direction to the working direction of rotation of the rotary tool and at the same time pulling it out of the chuck. Rotation opposite to the working direction of the rotary tool is not possible during operation, i.e. when a workpiece is being machined by the rotary tool.Furthermore, this rotational movement is also impossible during operation due to the torque-resistant press fit. Thus, the rotary tool cannot move axially out of the shrink fit chuck or similar device.

[0011] This ensures precise machining and dimensional accuracy can be maintained within the required tolerances. Since axial drift is prevented by the present invention, production can be efficient and cost-effective, as very little scrap is produced compared to conventional tool holders with chucks. This also eliminates another source of accidents and thus the risk of accidents for the machine operator.

[0012] Instead of balls that are press-fitted to rotate in the chuck, cylindrical pins with a partial or hemisphere on one of their ends can also be used. These lie in the bearing bore instead of the balls, although they require either a projecting projection to prevent the cylindrical pin from falling into the interior of the receiving opening, or an external thread that corresponds to the internal thread of the bearing bore. The advantage of using balls over cylindrical pins with a partial or hemisphere head is that inserting the rotary tool is easier than with cylindrical pins, as the balls are rotatably mounted and, unlike the cylindrical shaft, cannot jam. Balls can also be held in the respective bearing bore using a threaded pin. The cylindrical pin itself has a design on its end that accommodates the ball, e.g.in the form of a polygonal recess or a spherical indentation or the like. Instead of the threaded pin, dowel pins, bolts or the like can also be used.

[0013] The pull-out protection device according to the invention for tools, in particular rotary tools in tool holders with a tool holder, is particularly suitable for chucks such as collet chucks, hydraulic expansion chucks and shrink chucks.

[0014] Depending on the requirements, the locking grooves in the circumferential surfaces of the tool shank are expediently designed differently. Starting from the end face, the locking grooves can have a different locking groove profile. This can be helical, L-shaped, curved, or formed from a combination of partially straight and / or curved cylindrical surface paths. Particularly with a helical locking groove profile, the direction of rotation must correspond to the direction of rotation of the grooved tool. This means that for a left-handed tool, the helical locking groove must be formed with a left-hand inclination, while for a right-handed tool, it must be formed with a right-hand inclination. This also provides a locking effect for the pull-out protection.

[0015] In another embodiment, the shank of the tool has an external thread at the end, and the tool holder's tool receptacle has a corresponding internal thread. In this case, the pull-out protection is achieved using the external thread on the tool, which is left-handed for left-handed tools and right-handed for right-handed tools. In this embodiment, locking elements and locking grooves become obsolete.

[0016] In a particularly preferred embodiment, the bearing bores that accommodate the locking elements are preferably formed continuously from the outer peripheral surface of the tool holder into the interior of the tool holder that accommodates the tool. These bearing bores can be formed perpendicular to the rotational axis of the tool holder and intersecting the rotational axis and / or tangentially adjacent to the inner peripheral surface of the interior that accommodates the tool. The longitudinal axes of the bearing bores are preferably arranged at the same angle to one another and, in particular, in a plane perpendicular to the rotational axis of the tool holder.

[0017] In another particularly preferred embodiment, particularly for tool holders with shrink fit chucks, the balls are mounted as locking elements in a ball cage. The bearing bores for the respective balls in the ball cage each have a smaller bore diameter with respect to the inner circumferential surface than the bearing bore diameter. This prevents the balls from falling inwards into the interior of the tool holder, but merely projects beyond the interior of the ball cage. The ball cage can either be inserted into the interior of the tool holder as a separate component with a form-fitting fit, or be incorporated into a sleeve. The sleeve has the respective bearing bores with the smaller bearing bore diameters with respect to the interior.The sleeve can be pressed into the interior of the tool holder, shrunk in, welded to the tool holder, held in a form-fitting manner with additional threaded pins and / or fixed to the sleeve with locking elements and locking grooves, as described according to the invention on the shaft of rotary tools.

[0018] In a particularly preferred embodiment, especially for shrink fit chucks, the pull-out protection device additionally has a mechanism that enables the tool to be held in place with the pull-out protection device without any play. A force-exerting element, which is arranged, for example, concentrically to the tool's rotational axis at the base of the tool bore, pushes the tool in the tool holder out of the tool holder. As a result, the pull-out protection device rests on the tool without any play. Even a slight amount of play between the pull-out protection device and the tool allows the tool a certain degree of freedom of movement, which can lead to damage to the tool cutting edges. Compression springs in the form of spiral springs, conical springs, disc springs, disc spring assemblies, and / or elastic or rubber-elastic elements are particularly suitable as force-exerting elements.

[0019] In a further and particularly advantageous embodiment for a tool holder with minimum quantity lubrication, said tool holder has at least one transfer piece for the minimum quantity lubrication, which comprises at least one, preferably several channels for pressure build-up or pressure equalization. For such a tool holder with such a transfer piece, separate protection is sought, if necessary, independently of the pull-out protection. The transfer piece, preferably in the form of a tube, which can also be composed of several parts, is preferably formed with a radial flange and is preferably movably received and guided in a bore located in the tool holder. The tube, which can also have different cross-sectional profiles, is preferably mounted in the tool holder preloaded by a spiral spring, wherein the cylindrical shaft of the tube preferably penetrates the spiral spring.Of course, other force-exerting elements such as tension springs, conical springs, disc springs, and / or elastic elements, as well as combinations thereof, are also possible. The spiral spring is preferably arranged between the radial flange of the tube and, for example, a stop base in the tool holder, whereby the tube is preloaded relative to the tool holder. The transfer piece is preferably mounted in the bore in a sealed manner. Concentric with the bore for the transfer piece or tube, the tool holder has, for example, at least one shaft seal and / or other sealing elements such as sealing rings, sealing lips, etc., which can also be arranged in the tool holder and / or on the transfer piece or on the tube itself.The channels in the form of through-bores, in particular with a circular cross-sectional profile, although other cross-sectional profiles are also possible, are preferably arranged in the radial flange of the transfer piece, so that the through-bore in the transfer piece is connected to the through-bore in the radial flange of the transfer piece. A radial recess is arranged along the cylindrical circumferential surface of the radial flange of the transfer piece. An annular membrane, preferably in the shape of a cylindrical surface section and corresponding to the radial recesses, is embedded therein, preferably in a form-fitting manner. Both the circumferential surface recess, in particular in the form of a groove, and the preferably corresponding cross-section of the membrane embedded in the groove can have, for example, a partial spherical head profile or other profiles.The annular diaphragm is preferably made of an elastic material, particularly a rubber-elastic material, but other materials are also possible, such as carbon fiber, plastics, Teflon, and flexible metals. The channels for pressure equalization or pressure buildup are connected, in particular, to the diaphragm and the interior of the transfer piece. When pressure builds up in the tool holder, the diaphragm bulges radially and presses against the circumferential surface of the tool holder's mounting bore. This locks the transfer piece against axial displacement.

[0020] In the following, exemplary embodiments of the invention are explained with reference to drawings. In a purely schematic representation: Fig. 1 is a sectional view of the tool holder according to the invention with a shrink fit chuck and a separate, not yet clamped, end mill provided with locking grooves. Fig. 2 is a sectional view of the tool holder according to the invention with a shrink fit chuck and a clamped end mill according to the invention. Fig. 3 is a sectional view of the tool holder according to the invention with a collet chuck and a clamped end mill according to the invention. Fig. 4 is a sectional view of the tool holder according to the invention with a HG chuck and a clamped end mill according to the invention. Fig. 5 is a sectional view of the tool holder according to the invention with a hydraulic expansion chuck and a clamped end mill according to the invention. Fig. 6 is a sectional view of the tool holder according to the invention with a clamped end mill according to the invention, wherein the tool has an external thread and is screwed into a corresponding internal thread of the tool holder.Fig. 7 is a sectional view of the tool holder according to the invention with balls as locking elements, secured by threaded pins. Fig. 8 is a sectional view of the tool holder according to the invention with balls as locking elements, secured by threaded pins, the balls being partially countersunk into the threaded pins. Fig. 9 is a sectional view of the tool holder according to the invention with balls as locking elements, secured with cylindrical pins in a press fit. Fig. 10 is a sectional view of the tool holder according to the invention with a one-piece locking element, which is a threaded pin with a spherical shape on one of its end faces. Fig. 11 is a sectional view of the tool holder according to the invention with one-piece locking elements, which are cylindrical pins with a spherical shape on one of the end faces, in a press fit.Fig. 12 is a sectional view of the tool holder according to the invention with balls in a separate ball cage, with a sleeve adjacent thereto. Fig. 13 is a sectional view of the tool holder according to the invention with balls arranged in a ball cage incorporated in the sleeve, wherein the sleeve is pressed or shrunk in. Fig. 14 is a sectional view of the tool holder according to the invention from . Fig. 13 , wherein the sleeve is welded to the tool holder. Fig. 15 a sectional view of the tool according to the invention from Fig. 13 , wherein the sleeve is mechanically fixed with threaded pins with a conical dome. Fig. 16 a sectional view of the tool holder according to the invention with a slotted sleeve which receives the balls, and the sleeve is provided with locking grooves and is held on the tool holder via further balls and threaded pins. Fig. 17 a sectional view of the tool holder according to the invention with a conical spring for play-free pull-out protection. Fig. 18 a sectional view of the tool holder according to the invention with a length adjustment screw which is made of rubber-elastic material. Fig. 19 a sectional view of the tool holder according to the invention with a length adjustment screw which has an element made of rubber-elastic material integrated therein. Fig. 20 a sectional view of the tool holder according to the invention with minimum quantity lubrication, balls as locking elements and a membrane made of rubber-elastic material.21a sectional view and side view from . Fig. 20 of the tool holder according to the invention with tangential arrangement of the locking elements. Fig. 22 an enlarged view of an area of Fig. 20 of the tool holder according to the invention with the membrane and a pressure channel in the transfer piece.

[0021] Fig. 1 shows a schematic sectional view of the tool holder 1 and, by way of example, an end mill 2, which are arranged relative to one another with respect to a rotation axis 3. The tool holder 1 has at least two, preferably three or four balls 4. The ball is located in a bearing bore 5, which is arranged perpendicular to the rotation axis 3 and thus to the longitudinal axis, in the sleeve section 6 of the tool holder 1. This bearing bore 5 is a through-bore and extends from the outside of the sleeve section 6 to the inner circumferential surface of the receiving opening 7, which is arranged concentrically to the rotation axis 3 in the tool holder 1. The bearing front side 8 of the bearing bore 5 is in the shape of a spherical shallot and corresponds to the spherical shape of the ball 4, so that the ball 4 partially projects into the interior of the receiving opening 7.The ball 4 is held in its forward position, i.e., in a position protruding into the interior of the receiving opening 7, by a setscrew 9. The bearing bore 5 has an internal thread corresponding to the external thread of the setscrew 9. The length of the setscrew 9 does not protrude beyond the outer surface of the sleeve section 6. The setscrew 9 has a hexagon socket 10. The end mill 2 has helically arranged locking grooves 13, 14 on its cylindrical shank 11 near the end face 12. These have a spherical profile corresponding to the spherical shape of the ball 4. In order to fully clamp the end mill in the tool holder, the end mill must be rotated in the direction of rotation 15 when inserting the end mill, so that the end mill 2 is screwed axially helically into the receiving opening 7 until the end mill 2 reaches a stop.

[0022] Fig. 2 shows a purely schematic sectional view of the tool holder 1 in which the end mill 2 is completely clamped. The end mill 2 is located up to its stop with its cylindrical shank 11 in the receiving opening 7. The ball 4, held by the threaded pin 9, engages in the locking groove 13 or 14. In this sectional view, the cylindrical shank 11 is press-fitted with the receiving opening 7; ie the induction coil (not shown in the drawing) is switched off and the shrink fit chuck of the tool holder 1 has cooled down and shrunk back to its original size. As in Fig. 2 As can be clearly seen, an axial movement of the end mill 2 along the rotational axis 3 is not possible because the ball 4 sits in the spherical locking groove 13 or 14 in the cylindrical shaft 11, so that a movement along the rotational axis 3 is blocked. Thus, in this drawing, the interaction between the ball 4 and the locking groove 13 or 14 in the form of a lock becomes clear. To remove the end mill 2 from the tool holder 1, the end mill 2 must simply be turned against the direction of rotation 15 after switching on the induction coil (see Fig. 1 ) and pulled out of the tool holder 1 in the axial direction along the rotation axis 3.

[0023] The following figures show possible embodiments of how the pull-out protection is designed in other commercially available chucks.

[0024] Fig. 3 shows in a schematic sectional view a conventional collet chuck with union nut with the inventive pull-out protection by means of the locking groove and balls.

[0025] Fig. 4 shows an HG chuck with the inventive pull-out protection by locking grooves and balls.

[0026] Fig. 5 shows in a purely schematic sectional view a conventional hydraulic expansion chuck with inventive pull-out protection through the locking groove and balls.

[0027] Fig. 6 shows, in a purely schematic sectional view, a tool holder in the form of a shrink fit chuck, wherein the end mill is screwed to the tool via a thread 16. Due to this screw connection, which is designed to rise to the left for left-fluted tools and to rise to the right for right-fluted tools, an axial pull-out protection of the tool from the tool holder is achieved.

[0028] Fig. 7 shows, in a purely schematic sectional view, a shrink fit chuck with locking elements in the form of balls 4, which are held in the respective bearing bores 5 by threaded pins 9. The threaded pin 9 has a blunt end face.

[0029] Fig. 8 shows, in a purely schematic sectional view, a shrink fit chuck with locking elements in the form of balls 4, which are held in the bearing bores 5 by threaded pins 9. Threaded pin 9 has a recess 17 on the end face that accommodates the ball 4. The recess 17 is formed in the form of a blind hole or, for example, in the form of a hexagon socket corresponding to the diameter of the ball.

[0030] Fig. 9 shows, in a purely schematic sectional view, a shrink fit chuck with locking elements in the form of balls 4, which are held in the bearing bores 5 by dowel pins 18. Due to the interference fit between the dowel pin 18 and the bearing bore 5, the locking elements in the form of balls 4 are fixed in their position.

[0031] Fig. 10 shows a purely schematic sectional view of a shrink fit chuck with one-piece locking elements 19. Locking element 19 is a threaded pin which has a hemispherical head 20 on one of its end faces.

[0032] Fig. 11 shows a purely schematic sectional view of a shrink fit chuck with a one-piece locking element 19 in the bearing bores 5. The one-piece locking elements 19 are dowel pins that are press-fitted to the shrink fit chuck. The one-piece locking elements 19 have a hemispherical head 20 on one of their end faces.

[0033] Fig. 12 shows in a purely schematic sectional view a shrink fit chuck with locking elements in the form of balls 4. The balls 4 are in a ball cage fig 21 The ball cage is fig 21 at the bottom of the receiving opening 7. Adjacent to this is a sleeve 22. In the cage fig 21 The balls 4 are recessed and are pushed radially outward by the cage. The balls 4 are pressed against a shoulder located between the receiving opening 7 and a free rotation at the end of the receiving opening 7. The balls 4 can be axially supported on this shoulder. When the tool is shrunk in, the balls 4 are also supported inward and can thus secure both the tool 2 and the sleeve 22 against axial withdrawal.

[0034] Fig. 13 shows a purely schematic sectional view of a shrink fit chuck with the balls 4, which are located in a sleeve 22 in the left section of the sleeve and in the receiving opening 7. The left section of the sleeve 22 functions as a ball cage for the balls 4. The bearing bores 5 for the balls 4 in the sleeve 22 have a smaller diameter with respect to the inner cylindrical circumferential surface of the sleeve 22 than the diameter of the balls or the bearing bore diameter. This allows the balls 4 to protrude into the interior, but cannot fall in. The sleeve 22 is either shrunk or pressed into the chuck.

[0035] Fig. 14 shows a purely schematic sectional view of a shrink fit chuck with balls 4 in a sleeve 22. The sleeve 22 is connected to the sleeve section 6 with a weld seam 23. The welding of the sleeve 22 to the shrink fit chuck can be point-like, section-wise, or annular as a closed, for example, Y-seam.

[0036] Fig. 15 shows a purely schematic sectional view of a shrink fit chuck with balls 4 in a sleeve 22. In this embodiment, the sleeve 22 is fixed to the tool holder via threaded pins 24. The threaded pins 24 have, for example, a conical point. Of course, other designs, such as a spherical head, etc. are also possible. The sleeve 22 has corresponding recesses 25 to the end face of the threaded pins 24, which recesses correspond to the end face of the threaded pins 24. In the present embodiment, these recesses 25 are conical. To fix the sleeve 22 to the tool holder, at least one threaded pin 24 with a front face design, for example in the shape of a cone, is necessary. Preferably, three, particularly preferably four threaded pins are arranged to fix the sleeve 22 to the tool holder.

[0037] Fig. 16 shows a purely schematic sectional view of a shrink fit chuck with locking elements in the form of balls 4 arranged in the sleeve 22. The sleeve 22 has a thicker wall than in the previous figures. For this reason, the sleeve 22 is slotted (not shown in the drawing). In this embodiment, the sleeve 22 is also connected to the tool holder by balls. In the left area of ​​the sleeve 22 there are locking grooves 27 corresponding to the balls, which also have a spherical profile. Just as the tool is axially fixed in the shrink fit chuck by the interaction of locking elements and locking grooves, in this case the sleeve 22 is axially fixed in the outer circumferential surface of the sleeve 22 by balls 26 as locking elements with locking grooves 27. The balls 26 are located in bearing bores 28, which in turn connect threaded pins 29 to one another.In this case, too, the bearing bore 28 has a smaller diameter in the inner area toward the receiving opening 7 than the bearing diameter, which corresponds to the ball diameter of the ball 26. Thus, the ball 26 cannot fall into the interior, but rather protrudes into it.

[0038] Fig. 17 shows in a purely schematic sectional view a shrink fit chuck with an axial pull-out protection according to Fig. 2 . In addition, the tool holder has a conical spring 30, which is located between the end face 12 of the cylindrical shank 11 of the end mill 2 and the bottom 31 of the receiving opening 7. The compression spring in the form of a conical spring 30 presses on the end face 12 of the end mill 2 in the direction of the rotation axis 3 out of the tool holder 1. This eliminates any possible play or manufacturing tolerances of the locking groove in the circumferential surface of the cylindrical shank 11 and the respective position of the balls 4 in the tool holder 1, insofar as the end mill 2 is additionally locked in the axial direction by the force of the conical spring 3. This also eliminates any slight play between the axial pull-out protection and the tool. This eliminates the risk of additional damage to the tool cutting edges during operation due to small manufacturing tolerances.

[0039] Fig. 18 shows a purely schematic sectional view of a shrink fit chuck with locking elements in the form of balls 4. Here, the play-free pull-out protection of the tool after shrinking is achieved by using a length adjustment screw 32, which is preferably made of a rubber-elastic material. An internal thread 33 corresponding to the length adjustment screw 32 is formed in the tool holder. Fig. 18 Another possible design for the locking groove is also shown. In this embodiment, the locking groove 34 is formed in the shape of an "L," but begins at the end face 12 of the cylindrical shaft 11. This essentially creates a bayonet-like locking mechanism for axial locking to prevent the tool from being pulled out of the tool holder.

[0040] Fig. 19 shows in a purely schematic sectional view a shrink fit chuck made of Fig. 18 , wherein an elastic element 35 is arranged concentrically to the length adjustment screw 32. In this case, the elastic element 35 is preferably made of a rubber-elastic material. The play-free pull-out protection is achieved by the contact pressure exerted by the length adjustment screw 32 on the elastic element 35 via the end face 12 onto the end mill 2.

[0041] Fig. 20 shows a purely schematic sectional view of a shrink fit chuck with minimum quantity lubrication (MQL). The axial pull-out lock is provided by locking elements 36, which are in turn formed in the form of balls. Concentric to the rotational axis inside the shrink fit chuck is a movable tube 37, which is the transfer piece for the minimum quantity lubrication. The tube 37 is pressed against the tool shank (not shown in the drawing) by the spring force of a spiral spring 38. Fig. 20 Two possible end positions of the tube 37 are shown. The right-hand contact surface of the tube with the tool shank is conical in the form of a radial tube flange 39. The spiral spring 38 is concentrically penetrated by the tube 37. The spiral spring 38 is located between the base 31 and the conical-section-shaped peripheral surface of the tube 37 at the radial neck flange. Fig. 21 shows along the section line AA from Fig. 20 in a purely schematic sectional view the tangential arrangement of the locking elements 36 in the tool holder. Fig. 22 shows an enlarged section of a section from Fig. 20, which is marked with a dashed line. Through holes 40 are arranged in the radial neck flange 39 of the tube 37 and extend from the inner diameter of the tube 37 to the outer circumferential surface 41 of the radial tube flange 39. A concentric, cylindrical recess 42 is arranged along the cylindrical circumferential surface 41 of the radial tube flange 39 of the tube 37, the width of which is preferably smaller than the width of the cylindrical circumferential surface 41 of the tube flange 39. Corresponding to the recess 42 is an annular, cylindrical section-shaped membrane 43 which is flush with the outer cylindrical circumferential surface 41 of the tube flange 39. The membrane 43 is preferably made of a rubber-elastic material. This membrane 43 along the circumferential surface 41 seals the tube 37 against the wall of the receiving opening 7 of the shrink fit chuck.The bores 40, which lead radially to the inside of the diaphragm 43, transmit the air pressure to the diaphragm 43, which is thus pressed against the bore wall 7. Due to the pressure buildup, the diaphragm bulges radially and thus presses against the inner circumferential surface of the receiving opening 7 of the tool holder. This secures the tube 37, which serves as a transfer piece for the minimum quantity lubrication, against axial displacement. The movable tube 37 allows the lubricating mist to be directed to the tool without loss.

Claims

1. System consisting of a tool holder (1) and a tool (2), wherein the tool holder (1) has a tool receptacle, designed as a chuck, and a shank (11) of the tool (2), in particular rotational tool, that is received in said tool receptacle, wherein the tool holder (1) has a pull-out prevention means which blocks an axial migration of the tool (2) and comprises at least one blocking element (4, 19) and at least one mutually corresponding blocking groove (13, 14) which receives the blocking element (4, 19), said blocking groove (13, 14) and said blocking element (4, 19) interacting with one another in a form-fitting manner; wherein the chuck is a collet chuck, a hydro-expansion chuck or a shrink chuck, characterized in that the tool (2), in particular rotational tool, has at least two, preferably four, blocking grooves (13, 14, 34); wherein the blocking grooves (13, 14, 34) are disposed in the circumferential face of the shank (11) of the tool (2) and, proceeding from the end side (12), extend over at least a sub-portion of the shank (11).

2. System according to Claim 1, characterized in that the blocking element (4, 19) and the blocking groove (13, 14, 34) have an at least partially-ball-head-like design.

3. System according to Claim 1 or 2, characterized in that the chuck comprises the blocking element (4, 19), and the tool (2) comprises the blocking groove (13, 14, 34).

4. System according to one of the preceding claims, characterized in that the blocking groove profile is designed to be helical, L-shaped, curve-shaped, or assembled from cylindrical surface tracks which are in portions rectilinear and / or curved.

5. System according to Claim 4, characterized in that the helical blocking groove profile is designed as a left-handed pitch in the case of a left-handed grooved tool (2), and as a right-handed pitch in the case of a right-handed grooved tool (2).

6. System according to one of the preceding claims, characterized in that the shank (11) of the tool (2) on the end side has an external thread, wherein the external thread is designed as a left-handed pitch in the case of a left-handed grooved tool (2), and as a right-handed pitch in the case of a right-handed grooved tool (2), and the tool holder (1) has a mutually corresponding internal thread.

7. System according to one of the preceding claims, characterized in that the arrangement of the blocking elements (4, 19) in the tool holder (1), and the mutually corresponding arrangement of the blocking grooves (13, 14, 34) on the tool (2), are preferably mutually equiangular.

8. System according to one of the preceding claims, characterized in that the blocking elements in the tool holder (1) are in particular disposed in a plane perpendicular to the rotation axis of the tool (2).

9. System according to one of the preceding claims, characterized in that the blocking elements (4, 19) in the tool holder (1) are balls (4), pins, studs and / or threaded pins (19) which have at least one and at least partially-ball-head-like end-side convex design feature.

10. System according to Claim 9, characterized in that the blocking elements (4, 19) in the tool holder (1) are preferably formed from alloyed high-grade steel, wherein preferably at least the balls (4) and / or the partially-ball-head-like region of the blocking elements (19) are / is hardened.

11. System according to one of the preceding claims, characterized in that the blocking elements (4, 19) are mounted in bearing bores (5) in the tool holder (1), wherein the bearing bores (5) preferably extend continuously from the external circumferential face into the interior of the tool holder (1) that receives the tool (2), and said bearing bores are formed either to be perpendicular to the rotation axis (3) of the tool holder (1), and / or to be tangentially adjacent to the inner circumferential face of the interior that receives the tool (2).

12. System according to one of the preceding claims, characterized in that the blocking elements (4, 19) are preferably held in the bearing bores (5) by threaded pins (9) and / or an interference fit, and / or the blocking elements (4, 19) are designed with external threads that are designed to correspond to internal threads formed in the bearing bores (5).

13. System according to one of the preceding claims, characterized in that the blocking elements (4, 19) in their mounted position in the bearing bores (5), by way of the ball-head-like design feature, protrude at least partially into the interior of the tool holder (1) that receives the tool (2) .

14. System according to one of the preceding claims, characterized in that the blocking elements (4, 19), in particular balls (4), in tool holders (1), in particular shrink chucks, are mounted in at least one ball cage (21), wherein the bearing bores (5) for the balls (4) of the ball cage (21) in terms of the inside have a diameter smaller than the bearing bore diameter.

15. System according to Claim 14, characterized in that the tool holder (1) has at least one ball cage (21) in the interior of the tool holder (1), wherein the ball cage (21) as a separate component is incorporated in a sleeve (22), or is a sleeve (22) comprising a ball cage (21), wherein the sleeve (22) is press-fitted, shrink-fitted, welded to the tool holder (1), held in a form-fitting manner by threaded pins (24), and / or is fixed to the sleeve (22) using blocking elements (4, 19) and blocking grooves (13, 14, 34).

16. System according to one of the preceding claims, characterized in that the tool (2) with the pull-out prevention means, in particular in the case of shrink chucks, is held without axial play by force-exerting elements (30, 35, 38), in particular by at least one compression spring, conical spring (30), coil spring, plate spring as well as spring assemblies and / or rubber-elastic elements (35).

17. System according to one of the preceding claims, characterized in that the tool (2) with the pull-out prevention means, in particular in the case of chucks having minimal-quantity lubrication, is held without axial play, wherein the transfer piece (37) for the minimal lubrication has at least one through-bore (40) in the conical radial flange region, the radial flange (39) of the transfer piece (37) along the cylindrical circumferential face (41) thereof having a radial clearance (42) in which, in a mutually corresponding manner, a cylindrical-surface-portion-shaped annular diaphragm (43), preferably formed from a rubber-elastic material, rests so as to be embedded in a preferably form-fitting and flush manner, wherein the through-bores (40) extend from the interior of the transfer piece (37) radially to the diaphragm (43).