Thread cutting chuck

Description

[0001] The present invention relates to a thread cutting chuck for synchronous thread cutting according to the preamble of claim 1, which is known from the document DE 10 2017 106 409 A1.

[0002] During thread cutting, a thread is machined or cut into a workpiece using a tap. The thread of the tap has a specific pitch. Depending on the pitch of the tap, it is necessary to move the tap in an axial direction as a translational movement while cutting the thread. This is carried out by a machine-side drive, particularly a CNC machine tool. In addition, the tap also performs a rotational movement in a specific direction of rotation to cut the thread. The translational speed is also referred to as the feed rate, and this depends on the tap's pitch.In CNC machine tools, a computer synchronizes the thread cutting process by recording the machine's linear motion as the axial movement and the machine's rotary motion as the rotary or rotational movement using corresponding pulse generators. However, the accuracy of the machine's rotary motion and linear motion cannot be precisely recorded, and deviations also occur in the tap's pitch during thread production. Precise synchronization of the machine spindle or thread cutting chuck feed rate with the rotational movement is not entirely possible.

[0003] To prevent the occurrence of large axial forces on the tapping chuck in the tensile and compressive directions, particularly during reversal, i.e., when reversing the rotational movement at the end of the tapping process to unscrew the tap, it is already known to use elastomer elements to cushion axial play in the axial direction of the tapping chuck and tangential play in the direction of rotation of the tapping chuck between a shank and a clamping device for the tap, based on the elastic properties of the elastomer element. However, the elastomer element has essentially the same spring constant in two axial directions that are oriented opposite to each other. This also applies analogously to two opposite directions of rotation.However, when cutting a thread into a hole in a workpiece with a tap, it is generally necessary and desirable to have a different spring constant of the elastomer element available to cushion the axial play in the tensile and compressive directions to optimize the thread cutting process during axial movement. This also applies analogously to the direction of rotation, i.e., for cutting in one direction of rotation and for the opposite direction of rotation after reversing.

[0004] Tapping chucks comprise clamping devices for securing the tap. Synchronous chucks comprise collets, which require different collets to be kept on hand for taps of different sizes or diameters. This disadvantageously requires the laborious process of replacing the collets on the clamping device when replacing taps of different sizes, as well as maintaining a large number of collets for the different tap sizes. This is time-consuming and expensive.

[0005] Hydraulic chucks are also known. Even with hydraulic chucks, it is necessary to change the reducing bushings for different tap sizes, and a correspondingly large number of reducing bushings must be kept in stock. Hydraulic chucks therefore also require laborious changing of the reducing bushings for taps of different sizes. Furthermore, due to the design of hydraulic chucks with hydraulic devices, they are complex and expensive to manufacture.

[0006] DE 10 2012 215 036 A1 and EP 2 650 068 B1 show a hydraulic expansion chuck with a hydraulic expansion clamping mechanism integrated in a chuck body, which has an expansion clamping bush with a continuously cylindrical inner wall.

[0007] DE 23 41 642 C3 shows a chuck for drills with a chuck body intended for attachment to a work spindle, on which a clamping member with clamping jaws that can be moved at an angle to the chuck axis is mounted so as to be rotatable about the chuck axis.

[0008] EP 1 043 100 B1 shows a drill chuck with a chuck body that can be connected to a drill spindle and with clamping jaws that form a holder for the drilling tool and are guided in the chuck body.

[0009] DE 84 29 380 U1 shows a thread cutting chuck with a two-part chuck body consisting of a spindle connecting piece which can be connected to a drive spindle and a jaw guide piece which is provided with clamping jaws for the tool to be held in the chuck and which is connected to the spindle connecting piece in a pressure- and tensile-resistant manner by a joint in which the spindle connecting piece and the jaw guide piece are normally aligned coaxially to one another by the force of a spring, but can be tilted against one another in their axial direction, wherein an adjustably guided locking member is provided on the chuck body which can be adjusted in its guide from a position in which it does not hinder the tilting movement between the spindle connecting piece and the jaw guide piece into a position which rigidly connects the spindle connecting piece and the jaw guide piece.

[0010] EP 3 147 053 A1 discloses a chuck for clamping tools in an electric hand-held power tool, comprising a chuck body and clamping jaws movable relative to the chuck body, as well as an insert received within the chuck body. The insert has at least one centrally arranged polygonal receptacle for receiving and securing against rotation a corresponding polygonal end section of a tap, and the insert is captively received within the chuck body when the chuck is mounted. The chuck has no elastomer element for cushioning axial and tangential play, nor an axial and tangential stop, and is therefore unsuitable for drive with a CNC machine tool.

[0011] EP 2 650 068 B1 discloses a hydraulic expansion chuck with a hydraulic expansion mechanism integrated in a chuck body, which has an expansion bushing with a continuous cylindrical inner wall, and a reducing bushing arranged in the expansion bushing for receiving a shank tool, in particular a tap, wherein the reducing bushing is connected to the chuck body in a form-fitting, rotationally fixed manner on the outer circumference by an external polygonal profile which is positively received in an internal polygonal profile of the chuck body, wherein the reducing bushing is formed on the inner circumference by an internal polygonal profile for the form-fitting reception of an external polygonal profile at the shank end of the shank tool for a form-fitting, rotationally fixed connection with the shank tool, the form-fitting connection between the reducing bushing and the chuck body is limited in the axial direction to a longitudinal end section of the reducing bushing,and the form-fitting connection between the reducing bush and the shank tool is limited in the axial direction to a length end section of the reducing bush,

[0012] US 2018 / 0056401 A1 discloses a chuck for a tap with a torque limiting device. The torque limiting device comprises a torque transmission mechanism that interrupts the transmission of torque, so that the torque transmission mechanism, and thus also the tap, no longer rotates.

[0013] DE 197 36 891 A1 discloses a drill chuck for a drill.

[0014] SE 454 332 B shows a chuck with first upper jaws and second lower jaws as two arrangements of first and second jaws. The two arrangements of jaws are separated from each other by an elastic disc.

[0015] DE 81 22 325 U1 shows a thread cutting chuck.

[0016] The object of the present invention is therefore to provide a thread cutting chuck for synchronous thread cutting with a clamping device in which taps of different sizes can be easily fixed to the clamping device without having to replace complex parts of the clamping device.

[0017] This object is achieved with a thread cutting chuck for synchronous thread cutting, comprising a receiving shaft as a component of the thread cutting chuck for the machine-side drive, an intermediate part as a component of the thread cutting chuck, a clamping device as a component of the thread cutting chuck for the force-locking fixation of a tap, wherein the receiving shaft is connected to the clamping device via the intermediate part, at least one elastomer element for cushioning an axial play in the axial direction of the thread cutting chuck and a tangential play in the direction of rotation of the thread cutting chuck between the receiving shaft and the clamping device due to the elastic properties of the elastomer element,an axial stop for limiting the cushioned axial play with a first axial stop element and a second axial stop element, and a tangential stop for limiting the cushioned tangential play with a first tangential stop element and a second tangential stop element, a fixing device for positively fixing the tap in the direction of rotation of the tap on the clamping device, wherein the clamping device comprises three clamping jaws movable in the radial direction with a clamping mechanism for non-positively fixing the tap. Taps of different sizes can thus be fixed to the clamping device particularly easily, without the need to replace parts of the clamping device. The clamping jaws are movable in the radial direction, so that taps of different sizes, i.e. with different diameters, can be clamped.can be non-positively attached and fixed to the clamping surfaces of the clamping jaws. The at least one elastomer element for cushioning axial play in the axial direction of the thread-cutting chuck and tangential play in the direction of rotation of the thread-cutting chuck is necessary for a thread-cutting chuck for synchronous thread cutting on a machine-side drive, in particular a CNC machine tool. The axial and tangential stops are necessary in a thread-cutting chuck with an elastomer element because the cushioning of the axial play, or the axial play, cannot be unlimited, and an axial stop is necessary for precisely limiting the axial play. This applies analogously to the tangential play as a play for different rotational positions of the tap.

[0018] The axial stop limits the axial play in two opposing first and second axial directions, and the tangential stop limits the tangential play in two opposing first and second tangential directions and directions of rotation. Using the locking device, the tap can be secured to the clamping device indirectly with an adapter or directly with a positive fit to transmit torque in the direction of rotation, in addition to the force-locking fixation with the clamping jaws.

[0019] In a supplementary embodiment, the three clamping jaws are movable in the axial direction with the clamping mechanism. The clamping mechanism can apply compressive and / or tensile forces to the three clamping jaws, allowing the three clamping jaws to move in the axial direction, i.e., a movement with a movement component in the axial direction, in both axial directions.

[0020] In an additional embodiment, the clamping mechanism comprises a spindle drive for moving, in particular translationally, the three clamping jaws in the axial direction. The spindle drive preferably has an actuating element. The actuating element can be moved, for example, using an Allen key, in particular set in a rotational movement, so that the clamping mechanism can be actuated to move the clamping jaws by means of the spindle drive.

[0021] In a further embodiment, the clamping device, in particular the clamping mechanism, comprises a bearing for movably supporting the clamping jaws in a direction of movement of the clamping jaws at an acute angle to the axial direction. The bearing is designed such that a direction of movement of the clamping jaws in the axial direction toward an axial end of the clamping device causes a reduction in the distance between the clamping surfaces and a central longitudinal axis of the clamping device, and vice versa. The acute angle is expediently between 5° and 45°, in particular between 10° and 30°.

[0022] The bearing is expediently designed as a plain bearing. Preferably, the bearing is designed as a rolling bearing. The plain bearing is formed, for example, by a counter plain bearing surface as an inner cone of a sleeve of the clamping device, in particular of the clamping mechanism.

[0023] In a supplementary embodiment, due to the bearing of the clamping jaws, when the clamping jaws move with a movement component in the axial direction in a direction towards an axial end of the clamping device, the radial distance of the clamping jaws to a central longitudinal axis of the clamping device is reduced and vice versa.

[0024] In an additional embodiment, the geometry of the fixing device is designed to be substantially complementary to a fixing element with a substantially square cross-section and four flat fixing surfaces of the tap.

[0025] In a further embodiment, the fixing device comprises four counter-fixing elements with four flat counter-fixing surfaces as a counter-fixing arrangement. Two of the four counter-fixing surfaces are aligned parallel to each other, so that the counter-fixing surfaces of the counter-fixing elements can be placed on the fixing surfaces of the fixing element, preferably with a compressive force. For the positive fixing of the tap, the four flat fixing surfaces of the tap thus rest on the four counter-fixing surfaces of the fixing device. Preferably, one counter-fixing surface of the fixing device is aligned perpendicular to each two adjacent counter-fixing surfaces.

[0026] In a further embodiment, the fixing device has a plurality of counter-fixing arrangements formed one after the other in the axial direction for fixing elements of the taps in different sizes.

[0027] Preferably, the distance between each two opposite counter-fixing surfaces of the counter-fixing arrangements is greater, the smaller the distance of the counter-fixing arrangements to an axial end of the clamping device is.

[0028] In a supplementary embodiment, the distance between any two opposing counter-fixing surfaces of the counter-fixing elements can be changed by means of an adjusting mechanism in order to adapt to fixing elements of the taps of different sizes. By means of the adjusting mechanism, the counter-fixing elements can be moved or are movable, in particular in the radial direction, so that the distance between any two opposing counter-fixing surfaces can be changed in order to adapt to the fixing elements of the taps of different sizes. For large taps, the distances between any two opposing fixing surfaces are greater than for smaller taps. In an additional embodiment, the clamping device comprises a sleeve, in particular a sleeve with an inner cone as a counter-sliding bearing surface.Preferably, the adjusting mechanism can be actuated manually, in particular by means of an Allen key, and / or with an actuator, in particular an electric or hydraulic motor.

[0029] In a further variant, the sides of the clamping jaws facing a central longitudinal axis of the thread cutting chuck each have two projections and one recess each, and the one recess is formed in the tangential direction between the two projections, so that a clamping surface is formed on each of the two projections for placing and non-positively fixing an outer surface of a shank of the tap.

[0030] In an additional variant, the outer surface of the tap's shank can be non-positively fixed between the clamping surfaces and the outer surface of the tap's shank by linear or strip-shaped contact surfaces, in particular at least six linear or strip-shaped contact surfaces. For this purpose, the clamping surfaces rest on the outer surface of the tap's shank with a compressive force at the contact surfaces.

[0031] Advantageously, the at least one elastomer element is formed from an elastomer and / or plastic with a modulus of elasticity of the elastomer and / or the plastic between 0.05 GPa and 10 GPa.

[0032] In a further variant, the at least one elastomer element is designed as a spring, in particular a disc spring and / or spiral spring. The spring is preferably made of metal, in particular steel.

[0033] The at least one elastomer element is expediently designed as a resilient and / or elastic spring ring. The spring ring is preferably made of metal, in particular steel.

[0034] In an additional variant, the thread cutting chuck includes several elastomer elements.

[0035] In a further variant, the sides of the clamping jaws facing a central longitudinal axis of the thread cutting chuck each have a projection, so that on each projection a clamping surface is formed for placing and non-positively fixing an outer surface of a shank of the tap and the number of contact surfaces corresponds to the number of clamping jaws.

[0036] In a further embodiment, the clamping surfaces of the clamping jaws are convexly curved in a section perpendicular to the longitudinal axis of the thread cutting chuck and are preferably flat in a section parallel to the longitudinal axis of the thread cutting chuck.

[0037] In a further embodiment, the clamping surfaces of the clamping jaws are flat, in particular in a section perpendicular to the longitudinal axis of the thread cutting chuck.

[0038] In a supplementary variant, the minimum distance of the clamping surfaces to the central longitudinal axis of the thread cutting chuck is constant in the axial direction.

[0039] In another variant, the axial play, limited by the axial stop, is between 0.03 mm and 1.8 mm, in particular between 0.05 mm and 1 mm.

[0040] The tangential play limited by the tangential stop is preferably between 0.1° and 5°, in particular between 0.2° and 3°.

[0041] A clamping device according to the invention for securing a tool, in particular a tap, a drill, or a milling cutter, comprising three clamping jaws movable in the radial direction by means of a clamping mechanism for non-positively securing the tap, wherein the clamping device is designed according to at least one feature described in this patent application, in particular at least one feature relating to the clamping device. The clamping device can be used for a wide variety of purposes, for example, for drilling, turning, or milling machines for securing tools for machining. The tools of different sizes can thus be easily and quickly secured to the clamping device in a non-positive and preferably positive manner.

[0042] In a further embodiment, the clamping device comprises an adapter for the indirect positive fixing in the direction of rotation of the fixing element of the tap to the fixing device of the clamping device.

[0043] The adapter expediently has first adapter fixing surfaces for positive fixing to the fixing device and / or second adapter fixing surfaces for positive fixing to the fixing element.

[0044] In a further embodiment, the first adapter fixing surfaces are designed to complement the four counter fixing surfaces and / or the second adapter fixing surfaces are designed to complement the four fixing surfaces. A complementary geometry preferably means that the complementary geometries are suitable for the positive transmission of torque.

[0045] Advantageously, the geometry of the fixing device is designed to be substantially complementary to the first adapter fixing surfaces of the adapter and preferably vice versa.

[0046] In an additional embodiment, the clamping device comprises at least three clamping jaws, preferably three, four, five or six clamping jaws.

[0047] In a further embodiment, the dimensions of the clamping surfaces of the clamping jaws, in particular of all clamping jaws, are larger in the axial direction, in particular 2, 4, 5, 7, 10, 15 or 20 times larger, than the dimensions of the clamping surfaces of the clamping jaws in the radial direction.

[0048] In a supplementary embodiment, the clamping device comprises the clamping mechanism and / or a spindle drive and / or the sleeve and / or the at least three clamping jaws and / or the fixing device.

[0049] In a further embodiment, the size, in particular the extent of the counter-fixing surfaces in a direction parallel to the fictitious planes spanned by the counter-fixing surfaces and perpendicular to the axial direction, can be changed by means of an additional mechanism. The additional mechanism can be driven manually and / or by an actuator, in particular an electric motor or a hydraulic motor. This allows the size of the counter-fixing surfaces to be adapted to the size of the taps. For example, intermeshing teeth are formed on the counter-fixing elements and the counter-fixing surfaces in a central region, and the distance between the teeth is adjustable. The size-adjustable counter-fixing elements are installed in particular in a clamping device in which the distance between any two opposite counter-fixing surfaces of the counter-fixing elements can be adjusted by means of an adjusting mechanism.

[0050] In a supplementary embodiment, the thread cutting chuck comprises a first support element for applying a force to the elastomer element and the first support element rests on the elastomer element, a second support element for applying a force to the elastomer element and the second support element rests on the elastomer element.

[0051] In an additional variant, the elastomer element has a greater spring constant in a first axial direction than in a second axial direction and the first and second axial directions are aligned opposite to one another and / or the elastomer element has a greater spring constant in a first rotational direction than in a second rotational direction and the first and second rotational directions are aligned opposite to one another. The spring constant as a proportionality factor of the elastomer element is determined according to Hooke's law. Preferably, the spring constant in the first axial direction is at least 10%, 20%, 30%, 50%, 70%, 100%, 150%, 200% or 300% greater than the spring constant in the second axial direction. Preferably, the spring constant of the elastomer element in the first rotational direction is at least 10%, 30%, 50%, 70%, 100%, 150%, 200% or 300% greater than the spring constant in the second rotational direction.

[0052] In a further embodiment, the thread-cutting chuck, in particular the elastomer element and the first and second support elements, is designed such that the first and second support elements rest on the elastomer element to apply a compressive force to the elastomer element to cushion the axial and / or tangential play. The cushioning of the axial and / or tangential play is thus achieved by applying a compressive force to the elastomer element from the first and second support elements.

[0053] In a supplementary variant, the elastomer element between the first and second support element is divided in the axial direction into a first axial section and a second axial section.

[0054] The first axial section expediently has a smaller extension in the axial direction than the second axial section, so that the elastomer element has a greater spring constant in the first axial direction than in the second axial direction. Due to the different extensions of the first and second axial sections, the elastomer element can have a different spring constant in the first and second axial directions, even with a constant modulus of elasticity of the elastomer element. The greater the extension of an axial section, the smaller the spring constant of this axial section, and vice versa, with a constant modulus of elasticity of the elastomer element.

[0055] In a further embodiment, the first axial section has a larger modulus of elasticity in the axial direction than the second axial section, so that the elastomer element has a larger spring constant in the first axial direction than in the second axial direction. The larger the modulus of elasticity of an axial section, the larger the spring constant of that axial section.

[0056] In a further embodiment, the elastomer element between the first and second support element is divided in the direction of rotation into a first tangential section and a second tangential section.

[0057] In a supplementary embodiment, the first tangential section has a smaller extension in the tangential direction than the second tangential section in the tangential direction, so that the elastomer element has a larger spring constant in the first tangential direction than in the second tangential direction. The larger the extension of a tangential section, the smaller the spring constant of this tangential section, and vice versa, with a constant elastic modulus of the elastomer element.

[0058] In an additional variant, the first tangential section has a larger modulus of elasticity in the tangential direction than the second tangential section in the tangential direction, so that the elastomer element has the larger spring constant in the first tangential direction than in the second tangential direction.

[0059] In an additional embodiment, the first support element is designed as a pin and the second support element is designed as a boundary of a recess or vice versa.

[0060] In an additional variant, the elastomer element has a bore and the pin is arranged in the bore, so that the pin rests on a partial outer side of the elastomer element which delimits the bore and another partial outer side of the elastomer element rests on the second support element as the boundary of the recess.

[0061] In a supplementary embodiment, the pin is fastened to the receiving shaft and the recess is formed on the intermediate part, in particular a sleeve-shaped section of the intermediate part.

[0062] In an additional embodiment, the pin and / or the recess are oriented substantially radially. Substantially radially preferably means that the pin and / or the recess are oriented with a deviation of less than 30°, 20°, 10°, or 5° from a radial direction.

[0063] In a supplementary variant, the first axial stop element and / or the first tangential stop element are designed as a bolt and the second axial stop element and / or the second tangential stop element are designed as a radial limitation and / or axial limitation of a recess and the bolt is arranged within the recess.

[0064] In an additional embodiment, the bolt is attached to the intermediate part and the recess is formed on the receiving shaft or vice versa.

[0065] In an additional variant, the first axial stop element is arranged with a play in the first and second axial directions with respect to the second axial stop element.

[0066] In an additional variant, the first tangential stop element is arranged with a play in the first and second tangential directions with respect to the second tangential stop element.

[0067] In a supplementary embodiment, the first and / or second support element rests on the elastomer element with a compressive force.

[0068] Preferably, the first and / or second support element rests directly or indirectly on the elastomer element.

[0069] In a further embodiment, the elastomer element is divided into the first and second axial sections in the axial direction by the first or second support element and / or a bore in the elastomer element.

[0070] In a further embodiment, the elastomer element is divided into the first and second tangential sections in the direction of rotation by the first or second support element and / or a bore in the elastomer element.

[0071] The elastomer element is expediently made of an elastomer, in particular rubber and / or NBR and / or SBR (styrene-butadiene rubber) and / or EPDM and / or FKM and / or silicone.

[0072] In a further embodiment, the elastic modulus in GPa of the elastomer element is between 0.05 and 10, in particular between 0.5 and 5.

[0073] In a further embodiment, the elastomer element is made of plastic, in particular CFRP and / or GFRP, preferably fiber-reinforced CFRP and / or fiber-reinforced GFRP.

[0074] In an additional variant, the elastomer element is made of textiles and / or leather and / or metal, in particular steel and / or brass and / or aluminum.

[0075] In a supplementary embodiment, the elastomer element is made of paper or paper, in particular paper or cardboard with a honeycomb structure.

[0076] In an additional variant, at least one cavity, preferably several cavities, is / are formed in the elastomer element, in particular as at least one through-opening. The at least one cavity reduces the spring constant of the elastomer element, so that with a large number of cavities, the elastomer element functions approximately according to the principle of a leaf spring with several spring leaves.

[0077] In a further embodiment, the at least one cavity of the elastomer element is substantially crescent-shaped and / or semicircular and / or elliptical and / or circular in cross section.

[0078] Advantageously, no support element is arranged in the at least one cavity. When a force, in particular a compressive force, is applied to the elastomer element, the elastomer element can deform, and the volume of the at least one cavity decreases.

[0079] In a further variant, the receiving shaft and / or the intermediate part and / or the clamping device are made of metal, in particular steel.

[0080] In the following, embodiments of the invention are described in more detail with reference to the accompanying drawings.

[0081] It shows: Fig. 1a longitudinal section of a shank of a thread cutting chuck, Fig. 2a longitudinal section of an intermediate part of the thread cutting chuck, Fig. 3a side view of the intermediate part according to Fig. 2 of the thread cutting chuck, Fig. 4 a longitudinal section of the thread cutting chuck, Fig. 5 a cross section AA according to Fig. 1 of the shank, Fig. 6 an enlarged partial longitudinal section of the threaded chuck according to Fig. 4 , Fig. 7a a plan view of an elastomer element in a first embodiment in a first arrangement, Fig. 7b a plan view of the elastomer element in the first embodiment in a second arrangement Fig. 7c a perspective view of the elastomer element in the first embodiment, Fig. 8a a plan view of the elastomer element in a second embodiment in a first arrangement, Fig. 8b a plan view of the elastomer element in the second embodiment in a second arrangement, Fig. 8c a plan view of the elastomer element in the second embodiment in a third arrangement, Fig. 8d a plan view of the elastomer element in the second embodiment in a fourth arrangement, Fig. 9a a plan view of the elastomer element in a third embodiment in a first arrangement, Fig. 9b a plan view of the elastomer element in the third embodiment in a second arrangement, Fig.9c is a plan view of the elastomer element in the third exemplary embodiment in a third arrangement, Fig. 9d is a plan view of the elastomer element in the third exemplary embodiment in a fourth arrangement, Fig. 10a is a plan view of the elastomer element in a fourth exemplary embodiment in a first arrangement, Fig. 10b is a plan view of the elastomer element in the fourth exemplary embodiment in a second arrangement, Fig. 10a is a plan view of the elastomer element in the fourth exemplary embodiment in a third arrangement, Fig. 11a is a plan view of the elastomer element in a fifth exemplary embodiment in a first arrangement, Fig. 11b is a plan view of the elastomer element in the fifth exemplary embodiment in a second arrangement, Fig. 12 is a side view of a tap, Fig. 13 is a cross section BB of the tap according to. Fig. 12 , Fig. 14 a longitudinal section of a sleeve of a clamping device of the thread cutting chuck, Fig. 15 a side view of the clamping device, Fig. 16 a front view of the clamping device with clamping jaws in a first embodiment, Fig. 17 a view of a clamping jaw of the clamping device, Fig. 18 a cross section CC according to Fig. 19 a fixing device in a first embodiment of the clamping device, Fig. 19 a plan view of the fixing device according to Fig. 18 , Fig. 20 a cross section DD according to Fig. 21 the fixing device in a second embodiment of the clamping device, Fig. 21 a plan view of the fixing device according to Fig. 20 , Fig. 22 a plan view of the fixing device in a third embodiment, Fig. 23 a front view of the clamping device with clamping jaws in a second embodiment, Fig. 24 a partial cross-section through a clamping jaw and a shank of the tap in a second embodiment of the clamping jaw and Fig. 25 a partial cross-section through a clamping jaw and the shank of the tap in a third embodiment of the clamping jaw.

[0082] A thread cutting chuck 1 is fastened by a mounting shank 2 to a machine-side drive (not shown), in particular a CNC machine tool. A tap 6 is fastened to a clamping device 4 in a force-fitting and preferably form-fitting manner for machining a thread in a workpiece (not shown). The mounting shank 2 is mechanically coupled and connected to the clamping device 4 by means of an intermediate part 3. The mounting shank 2, the clamping device 4, and the tap 6 each form components 5 of the thread cutting chuck 1. The mounting shank 2 has a first central bore 31 with a larger diameter than a second central bore 32. An external thread 20 on the mounting shank 2 serves for the mechanical coupling to the machine-side drive. Furthermore, a step 30 is formed on the outside of the mounting shank 2, which acts as a stop for the intermediate part 3.Like the thread-cutting chuck 1, the receiving shank 2 has a central longitudinal axis 46, which simultaneously forms a rotational axis 47 of the thread-cutting chuck 1. An axial direction 48 is thus aligned parallel to the central longitudinal axis 46 and the rotational axis 47 of the thread-cutting chuck 1. A radial direction 50 is aligned perpendicular to the central longitudinal axis 46 and thus also to the rotational axis 47. A tangential direction 49, as a rotational direction 49, is perpendicular to the plane of the drawing. Fig. 1 , 2 , 3 and 4aligned. Two fastening bores 29 are machined as blind holes in the radial direction 50 on the receiving shaft 2. Furthermore, two recesses 28 are machined on the outside of the receiving shaft 2. An axial boundary 44 of the recess 28 forms a second axial stop element 24 and a radial boundary 41 of the recess 28 forms a second tangential stop element 26. A centering pin 21 is formed on an end of the receiving shaft 2 opposite the external thread 20 and facing the machine-side drive ( Fig. 1 ). The recess 28 of the receiving shaft 2 has the radial boundary 41 in the radial direction 50. The radial boundary 41 is divided into a first flat section 42 and a second flat section 43 ( Fig. 5 ). In the axial direction 48, the recess 28 is delimited by two axial boundaries 44.

[0083] The intermediate part 3 has a central bore 37 with a constant diameter. On the outside of the intermediate part 3, facing the external thread 20, a conically tapered section 36 is formed. Two continuous recesses 19 are formed on the intermediate part 3, which are aligned in the radial direction 50. The recesses 19 are delimited by a boundary 45 of the intermediate part 3, and the boundaries 45 of the recesses 19 form second support elements 18. Furthermore, a total of four fastening bores 38 are formed on a sleeve-shaped section 22 of the intermediate part 3. Two fastening bores 38 are aligned with one another in the radial direction 50, and a bolt 27 is arranged and fastened in each of the two aligned bores 38. At an end of the intermediate part 3 facing the tap 6, a central centering bore 40 for the centering pin 21 is formed.A partial area 39 of the fastening bore 38 projects into the central bore 37 of the intermediate part 3, so that in one area the bolt 27 is arranged partly in the partial area 39 of the fastening bore 38 and additionally partly in the recess 28 (. Fig. 6 ).

[0084] An elastomer element 7 ( Fig. 7a, 7b, 7c ) made of rubber as an elastomer, has a bore 33 which is aligned substantially in the radial direction 50, i.e. with a deviation of less than 30°, 20°, 10° or 5°, to the radial direction 50 of the thread cutting chuck 1, analogous to the fastening bores 29 in the receiving shaft 2. The bores 33 of the elastomer element 7 are delimited by a partial outer side 34 of the elastomer element 7. In each of the two fastening bores 29 of the receiving shaft 2, a pin 17 made of metal, in particular steel, is fastened as a first support element 16, substantially aligned in the radial direction 50. A partial region of the pin 17 protrudes from the fastening bore 29 and is arranged in the bore 33 of the elastomer element 7. The thread cutting chuck 1 has two elastomer elements 7, each of which is arranged in the recess 19 of the intermediate part 3, with the pin 17 being arranged in the bore 33 of the elastomer element 7.Thus, a partial outer side 35 of the elastomer element 7 rests on the boundary 45 of the recess 19 of the intermediate part 3. Preferably, the extension of the elastomer element 7 is designed such that, even without stress on the thread-cutting chuck 1, the partial outer side 35 rests elastically prestressed on the boundary 45 and the partial outer side 34 at the bore 33 rests elastically prestressed on the pin 17, i.e., there is always contact between the partial outer side 34 of the bore 33 and the pin 17 and between the partial outer side 35 of the elastomer element 7 and the boundary 45.

[0085] In each of the two aligned fastening holes 38 of the intermediate part 3, a bolt 27 is fastened, which forms a first tangential stop element 25 and a first axial stop element 23. One of the two bolts 27 is partially arranged in the recess 28. In Fig. 5 the bolts 27 are shown in dashed lines. Without any stress on the thread cutting chuck 1 with forces, the bolt 27 has play with respect to both axial limits 44 of the recess 28 and also with respect to the radial limit 41 of the recess 28. The bolt 27 and the radial limit 41 as well as the axial limit 44 thus form an axial stop and a tangential stop for limiting the cushioned axial and tangential play on the clamping device 4 and thus also on the tap 6. If the outer side of the steel bolt 27 comes to rest on one of the two axial limits 44 in a first or second axial direction, the cushioned axial play of the clamping device 4 is limited.Similarly, the cushioned tangential play of the clamping device 4 is limited in the direction of rotation as soon as the bolt 27 rests on the radial limit 41, i.e., either on the first flat section 42 or the second flat section 43, to limit the cushioned axial play in the first or second direction of rotation. Due to the flat design of the first and second flat sections 42, 43 of the radial limit 41, the cylindrical bolt 27 rests over a large area on the radial limit 41, so that no stress peaks can occur between the bolt 27 and the radial limit 41 of the intermediate part 3.

[0086] The elastomer element 7 is made of rubber with a constant modulus of elasticity. In a first axial direction (left of the bore 33 according to Fig. 7a ) the elastomer element 7 in the first embodiment according to Fig. 7a a first axial section 8 with an extension 10 on and in a second axial direction (to the right of the bore 33 according to Fig. 7a ) has a second axial section 9 with an extension 11. In the tangential direction 49, the elastomer element 7 ( Fig. 7a ) a first tangential section 12 (above the bore 33 according to Fig. 7a ) in a first direction of rotation and a second tangential section 13 (below the bore 33 according to Fig. 7a ) in a second direction of rotation. The first tangential section 12 has an extension 14 and the second tangential section 13 has an extension 15. The extension 10 of the first axial section 8 is significantly larger than the extension 11 of the second axial section 9. The first axial section 8 serves to elastically cushion the axial play in the first axial direction and the second axial section of the elastomer element 7 serves to cushion the axial play in the second axial direction. In an analogous manner, the first tangential section 12 serves to elastically cushion the tangential play in a first direction of rotation and the second tangential section 13 serves to elastically cushion the tangential play in a second direction of rotation of the thread cutting chuck 1.The first tangential section 12 is significantly larger in extent 14 than the extent 15 of the second tangential section 13, so that the first tangential section 12 has a smaller spring constant than the second tangential section 13. Accordingly, the first axial section 8 has a smaller spring constant than the second axial section 9. The first and second axial directions and the first and second directions of rotation can be defined arbitrarily on the thread-cutting chuck 1. The elastomer element 7 in the first exemplary embodiment is substantially straight and partially circular on the outer side 35 for insertion into the correspondingly complementary boundary 45.

[0087] In Fig. 8a bis 8d a second embodiment of the elastomer element 7 is shown. The outer part 35 of the elastomer element 7 is designed in the shape of a cylinder jacket, so that the elastomer element 7 can be arranged in a cylinder jacket-shaped boundary 45 (not shown) of the recess 19 of the intermediate part 3 in different rotational positions, so that with an identical elastomer element 7, different extensions 10, 11 of the first and second axial sections 8, 9 and different extensions 14, 15 of the first and second tangential sections 12, 13 can be achieved according to the Fig. 8a bis 8d . This applies analogously to a third embodiment ( Fig. 9a, 9b, 9c, 9d ) of the elastomer element 7, which is square on the outer part 35.

[0088] In Fig. 10a bis 10c A fourth embodiment of the elastomer element 7 is shown. The partial outer side 35 of the elastomer element 7 is essentially triangular in shape and by a different arrangement of the identical elastomer element 7 in a correspondingly complementary triangular boundary 45 of the recess 9, different dimensions 10, 11, 14, 15 can be achieved in accordance with the embodiments described above and this applies analogously to the fifth embodiment of the elastomer element 7, which in the Fig. 11a und 11b is shown.

[0089] A tap 6 is attached to the thread cutting chuck 1. By means of the tap 6, a thread is machined into a workpiece. During the machining of the thread, the thread cutting chuck 1 is moved by a machine-side drive, in particular a CNC machine tool, in the axial direction 48 at a specific feed rate and simultaneously moved in the tangential direction 49 at a specific angular speed as well as a specific rotational speed corresponding to the pitch of the tap 6. Due to manufacturing inaccuracies in the pitch of the tap 6 and the fact that the thread cutting chuck 1 cannot be guided with absolute precision in the axial direction 48 at the feed rate and the angular speed or rotational speed in the tangential direction 49 orIn the direction of rotation 49, deviations occur between the pitch of the tap 6 and the necessary feed and rotation speed of the tap 6. For this reason, it is necessary, in particular to avoid high forces occurring on the thread cutting chuck 1, to provide axial and tangential play in the axial and tangential directions 48, 49, which is elastically cushioned by the elastomer element 7. In order to optimize the machining of a thread by means of the tap 6, it is necessary to provide a different optimized spring constant in the first and second axial directions, specifically for the axial play in the first axial direction and the second axial direction. This applies analogously to the tangential play, specifically in the first direction of rotation and the second direction of rotation.Due to the structural design of the elastomer element 7 at the boundary 45 and the pin 17 with different extensions 10, 11 in the first and second axial sections 8, 9 and different extensions 14, 15 in the first and second tangential sections 12, 13, different spring constants in the first and second axial directions and in the first and second rotational directions can be easily achieved. By appropriately designing the geometry of the boundary 45 and the partial outer side 35 of the elastomer element 7, different spring constants in the first and second axial directions and in the first and second rotational directions can be advantageously achieved simply by a different rotational position of the elastomer element 7 in the boundary 45 of the recess 19.The thread cutting chuck 1 is therefore inexpensive to manufacture, reliable in operation and, due to its structural design, can easily have different spring constants in the axial and rotational directions to optimize the cutting of a thread with the tap 6.

[0090] The tap 6 comprises a fixing element 60 ( Fig. 12 und 13 ) at a rear end region and a cutting geometry at a front end region of the tap 6. When the tap 6 is fixed to the clamping device 4 of the thread cutting chuck 1, the central longitudinal axis 46 of the thread cutting chuck 1 corresponds to the central longitudinal axis 46 of the tap 6 and at the same time the rotational axis 47 of the thread cutting chuck 1 corresponds to the rotational axis 47 of the tap 6. The fixing element 60 is essentially square in cross section ( Fig. 13 ), so that four flat, essentially rectangular or square fixing surfaces 61 are formed on the fixing element 60. Chamfers 62 are provided between the fixing surfaces 61 to avoid sharp edges. Fig. 14 bis 19 A first embodiment of the clamping device 4 is shown. The clamping device 4 comprises a sleeve 51 and at an end region of the sleeve 51 in the region of an axial end 55 of the clamping device 4, an inner cone 52 is formed, which forms a counter-sliding bearing surface 53 for clamping jaws 56 of the clamping device 4. The inner cone 52 tapers towards the axial end 55. At the axial end 55, an opening 54 is also formed for the introduction of an end region of the tap 6. The clamping jaws 56 ( Fig. 17 ) each comprise a clamping surface 57 and a sliding bearing surface 58. The clamping surface 57 has a convex surface, in particular in a section perpendicular to the plane of the drawing of Fig. 16 , i.e., with a cutting plane perpendicular to the central longitudinal axis 46. The clamping surfaces 57 of the clamping jaws 56 are aligned parallel to the central longitudinal axis 46. The sliding bearing surface 58 of each clamping jaw 56 rests on the counter-sliding bearing surface 53 of the sleeve 51 as a clamping mechanism, so that a sliding bearing is formed between the sliding bearing surfaces 58 of the clamping jaws 56 and the counter-sliding bearing surface 53 as an inner cone 52 of the sleeve 51. The clamping mechanism of the clamping device 4 further comprises a clamping mechanism (not shown) with a spindle drive. This spindle drive can be actuated by means of an actuating element when stationary using an Allen key, so that the three clamping jaws 56 can be moved in the axial direction 48, i.e., in a direction of movement with a movement component in the axial direction 48.Due to the sliding bearing of the sliding bearing surface 58 of the clamping jaws 56 on the counter sliding bearing surface 53 of the sleeve 51, an axial movement of the clamping jaws 56 in the direction of the axial end 55 causes a reduction in the radial distance of the clamping surfaces 57 to the central longitudinal axis 46. In order to fix small taps 6 to the clamping device 4, the clamping jaws 56 must therefore be moved in the direction of the axial end 55 with the clamping mechanism, and in order to fix large taps 6, the clamping jaws 56 must be moved in the direction away from the axial end 55, so that the radial distance of the clamping surfaces 57 to the central longitudinal axis 46 increases.For the non-positive fixing of the tap 6 to an outer surface 71 of a shank of the tap 6 outside the cutting geometry 59 and the fixing element 60, i.e. on the shank between the cutting geometry 59 and the fixing element 60, a clamping surface 57 of the clamping jaws 56 can be placed with a large compressive force on the outer surface 71 of the shank of the tap 6 by means of the clamping mechanism, so that a reliable non-positive fixing of the tap 6 to the clamping device 4 can be carried out. In . Fig. 15 the clamping jaws 56 are not shown and the fixing element 60 (shown in dashed lines) is not yet arranged in the smaller counter-fixing arrangement 66 with counter-fixing surfaces 65 (shown in dashed lines).

[0091] The clamping device 4 additionally comprises a fixing device 63 for the positive, indirect and direct fixing of the tap 6 in the direction of rotation 49 on the clamping device 4 and for the tangential alignment of the tap 6 to the thread cutting chuck 1 and the clamping device 4. As a result, a torque can be additionally applied by means of the positive fixing from the clamping device 4 to the tap 6. The fixing device 63 ( Fig. 15 , 16 , 18 und 19 ) comprises two counter-fixing arrangements 66. Each counter-fixing arrangement 66 has four flat counter-fixing surfaces 65, and the counter-fixing surfaces 65 are aligned at a right angle to adjacent counter-fixing surfaces 65. Two opposing counter-fixing surfaces 65 are aligned parallel to each other. The counter-fixing surfaces 65 are each formed on a counter-fixing element 64 and in the first embodiment of the fixing device 63 according to Fig. 15 , 16 , 18 und 19 The counter-fixing elements 64 are formed in one piece. The counter-fixing arrangement 66 with the smaller distance from the axial end 55 has a larger distance between the opposite counter-fixing surfaces 65. This allows fixing elements 60 in two different sizes to be directly fastened and fixed to the fixing device 63 in a form-fitting manner by placing the fixing surfaces 61 of the screw tap 6 directly onto the counter-fixing surfaces 65 of the fixing device 63. The geometry of the counter-fixing surfaces 65 is thus complementary to the geometry of the fixing element 60. For the sake of simplicity, only two counter-fixing arrangements 66 for screw taps 6 in two different sizes are shown in the described first exemplary embodiment of the fixing device 63.In practice, however, such fixing devices 63 have a large number of counter-fixing arrangements 66, for example 10 to 20 counter-fixing arrangements 66, so that a large number of taps 6 in different sizes, that is to say for example taps 6 in 10 to 20 different sizes, can be positively fastened to the fixing device 63 for transmitting a torque.

[0092] As an alternative to this, the fixing element 60 can be indirectly fixed in a form-fitting manner to the counter-fixing surfaces 65 of the fixing device 63 using a simply designed adapter (not shown). The adapter is used to be able to fasten taps 6 to large fixing devices 63 and / or large counter-fixing arrangements 66 with a large distance from opposite counter-fixing surfaces 65, using a small fixing element 60 with a small distance from opposite fixing surfaces 61. For this purpose, the adapter has corresponding first adapter fixing surfaces for form-fitting fixing to the fixing device 63 and second adapter fixing surfaces for form-fitting fixing to the fixing element 60. The first adapter fixing surfaces are designed to be complementary to the four counter-fixing surfaces 65. The second adapter fixing surfaces are designed to be complementary to the four fixing surfaces 61.It is also possible, if the taps 6 are indirectly secured to the fixing device 63 exclusively by means of the adapter, to design the geometry of the counter-fixing surfaces 65 of the fixing device 63 and the first adapter fixing surfaces of the adapter in any way deviating from this description. The clamping device 4 preferably comprises several adapters of different sizes.

[0093] In Fig. 20 und 21 a second embodiment of the fixing device 63 is shown. In the following, essentially only the differences from the first embodiment according to Fig. 18 und 19 The fixing device 63 has in the section according to Fig. 20 outside the counter-fixing surfaces 65 a conically enlarging opening in the direction of the axial end 55. The positive fixing of the fixing element 60 takes place only on a partial area of ​​the fixing surfaces 61 in the area of ​​the chamfers 62 of the tap 6. For this purpose, the pairs of two counter-fixing surfaces 65 are aligned at a right angle to one another and the pairs of the counter-fixing surfaces 65 have a conically opening geometry in the axial direction 48 in the direction of the axial end 55. The total of four pairs of counter-fixing surfaces 65, i.e. a total of eight counter-fixing surfaces 65, thus enable the positive fixing for transmitting the torque to the fixing surfaces 61 of the tap 6 in the region of the chamfers 62. Centrally between the chamfers 62 on the fixing surfaces 61, no counter-fixing surface 65 of the fixing device 63 rests on the fixing surfaces 61.

[0094] In Fig. 22 a third embodiment of the fixing device 63 is shown. In the following, essentially only the differences from the first embodiment of the fixing device 63 are described. The counter-fixing elements 63 are designed as separate components, i.e., a counter-fixing surface 65 is formed on each of the four counter-fixing elements 64 as separate components. The counter-fixing elements 64 can be moved in the radial direction 50 using an additional mechanism (not shown), so that the distances between the counter-fixing surfaces 65 change in order to adapt to screw taps 6 of different sizes. The counter-fixing surfaces 65 rest on the fixing surfaces 61 for the positive fixing of the screw tap 6.The size of the counter-fixing surfaces 65 is designed such that, for larger taps 6, they only cover a portion of the fixing surfaces 61 of the fixing element 60 of the tap 6, and / or the size of the counter-fixing surfaces 65 is mechanically adjustable. The adjustment mechanism can be operated either manually or by means of an actuator, for example, an electric motor.

[0095] In Fig. 23 a front view of the clamping device 4 with clamping jaws 56 is shown, each having two clamping surfaces 57 per clamping jaw 56.

[0096] Fig. 24 shows in detail the geometry of a clamping jaw 56 with two clamping surfaces 57 in a second embodiment, which rest on an outer surface 71 of a shank of the tap 6 for the frictional fixing of the tap 6. On the clamping jaw 56, a first clamping surface 67 and a second clamping surface 68 are each formed on a radial projection 72 and in the tangential direction 49 between the radial projections 72, a radial recess 73 is formed. The radial projections 72 and the radial recess 73 extend in the direction of the longitudinal axis 46 in the axial direction 48 on the clamping jaw 56. The radial projections 72 are in a section according to Fig. 24 perpendicular to the longitudinal axis 46 of the thread-cutting chuck 1, the radial end regions are convexly curved, so that the outer surface 71 of the tap 6 rests on the first clamping surface 67 at a first linear or strip-shaped contact surface 69 on the outer surface 71, and on the second clamping surface 68 at a second linear or strip-shaped contact surface 70 on the outer surface 71. The geometry of the two clamping surfaces 57, 67, 68 is matched to the different radii of curvature of the outer surfaces 71 of taps 6 with a shank of different diameters, so that the outer surfaces 71 always rest on the convexly curved clamping surfaces 67, 68. A center plane 74 parallel to the longitudinal axis 46 and centrally through the clamping jaw 56 is a plane of symmetry of the clamping jaw 56.The side of the clamping jaw 56 facing the central longitudinal axis 46 and the rotational axis 47 thus has a minimum radial distance from the longitudinal axis 46 and the rotational axis 47 at the first and second clamping surfaces 67, 68 and a maximum radial distance from the longitudinal axis 46 and the rotational axis 47 at the recess 73. The minimum radial distance of all clamping surfaces 67, 68 of all three clamping jaws 56 in the axial direction 48 in the direction of the longitudinal axis 46 is constant and preferably the maximum radial distance of all recesses 73 of all three clamping jaws 56 in the axial direction 48 in the direction of the longitudinal axis 46 is also constant.

[0097] Fig. 25 shows in detail the geometry of a clamping jaw 56 with two clamping surfaces 57 in a third embodiment, which rest on an outer surface 71 of a shank of the tap 6 for the non-positive fixing of the tap 6. In the following, essentially only the differences to the second embodiment according to Fig. 24 described. The first and second clamping surfaces 67, 68 are formed as flat surfaces on projections 72 that are essentially triangular in cross-section. The flat clamping surfaces 67, 68 are aligned at an acute angle to a center plane 74 parallel to the longitudinal axis 46 and centrally through the clamping jaw 56, so that the recess 73 is formed in the tangential direction 49 between the two projections 72. The center plane 74 is also a plane of symmetry of the clamping jaw 56 in the third embodiment.

[0098] Overall, the thread cutting chuck 1 according to the invention offers significant advantages. By means of the clamping device 4, taps 6 of different sizes can be reliably secured to the clamping device 4 in a form-fitting and force-fitting manner. Taps 6 of different sizes, i.e., in particular, taps with different shank diameters and different distances between the opposing fixing surfaces 61 of the fixing elements 60 of the taps 6, can be fixed to the clamping device 4 easily, reliably, and inexpensively without replacing any parts of the clamping device 4.

Claims

1. Thread-cutting chuck (1) for synchronous thread cutting, comprising - a receiving shank (2) as a component (5) of the tapping chuck (1) for the machine-side drive, - an intermediate part (3) as a component (5) of the thread-cutting chuck (1), - a clamping device (4) as a component (5) of the thread-cutting chuck (1) for the force-fit fixation of a tap (6), - whereby with the intermediate part (3) the receiving shank (2) is connected to the clamping device (4), - at least one elastomer element (7) for spring suspension of an axial clearance in the axial direction (48) of the thread-cutting chuck (1) and tangential clearance in the direction of rotation (49) of the thread-cutting chuck (1) between the receiving shank (2) and the clamping device (4) due to the elastic properties of the elastomer element (7), - an axial stop for limiting the spring-suspended axial clearance with a first axial stop element (23) and a second axial stop element (24) and a tangential stop for limiting the spring-suspended tangential clearance with a first tangential stop element (25) and a second tangential stop element (26), - a fixing device (63) for the form-fitting fixation of the tap (6) in the direction of rotation (49) of the tap (6) to the clamping device (4), characterized in that the clamping device (4) comprises three clamping jaws (56) movable in the radial direction (50) with a clamping mechanism for the force-fit fixation of the tap (6).

2. Thread-cutting chuck according to claim 1, characterized in that the three clamping jaws (56) are movable in the axial direction (48) with the clamping mechanism.

3. Thread-cutting chuck according to claim 1 or 2, characterized in that the clamping mechanism comprises a spindle drive for moving the three clamping jaws (56) in the axial direction (48).

4. Thread-cutting chuck according to claim 3, characterized in that the clamping device (4) comprises a bearing for the movable bearing of the clamping jaws (56) in one direction of movement of the clamping jaws (56) at an acute angle to the axial direction (48).

5. Thread-cutting chuck according to claim 4, characterized in that the bearing is designed as a plain bearing (53).

6. Thread-cutting chuck according to one or more of the preceding claims, characterized in that due to the bearing of the clamping jaws (56) with a movement component in the axial direction (48) in a direction to an axial end (55) of the clamping device (4), the radial distance of the clamping jaws (56) to a centric longitudinal axis (46) of the clamping device (4) is reduced and vice versa.

7. Thread-cutting chuck according to one or more of the preceding claims, characterized in that the geometry of the fixing device (63) is in the main complementary to a fixing element (60) of the tap (6), which is in the main square in cross-section, with four plane fixing surfaces (61).

8. Thread-cutting chuck according to one or more of the preceding claims, characterized in that the fixing device (63) comprises four counter-fixing elements (64) with four plane counter-fixing surfaces (65) as a counter-fixation arrangement (66) and in each case two of the four counter-fixing surfaces (65) are aligned parallel to each other, so that the counter-fixation surfaces (65) of the counter-fixing elements (64) can be laid on the fixation surfaces (61) of the fixation elements (60), preferably with a compressive force.

9. Thread-cutting chuck according to claim 8, characterized in that the fixing device (63) has several counter-fixation arrangements (66) formed one after the other in axial direction (48) for fixing elements (60) of the taps (6) in different sizes.

10. Thread-cutting chuck according to claim 8, characterized in that the distance between each two opposing counter-fixation surfaces (65) of the counter-fixation arrangements (66) is the greater, the smaller the distance is between the counter-fixation arrangements (66) to an axial end (55) of the clamping device (4).

11. Thread-cutting chuck according to one or more of claims 8 to 10, characterized in that the distance between each two opposing counter-fixation surfaces (65) of the counter-fixing elements (64) is changeable by means of an adjustment mechanism for the adaptation to fixing elements (60) of the taps (6) in different sizes.

12. Thread-cutting chuck according to one or more of the preceding claims, characterized in that the sides of the clamping jaws (56) facing to a centric longitudinal axis (48) of the thread-cutting chuck (1) each have two protrusions (72) and one recess (73) and each recess (73) is designed in the tangential direction (49) between each of the two protrusions (72), so that at each of the two protrusions (72) a clamping surface (57, 67, 68) is designed for the laying and force-fit fixation of an outer surface (71) of a shank of the tap (6).

13. Thread-cutting chuck according to claim 12 characterized in that, the outer surface (71) of the shank of the tap (6) with linear-shaped or strip-shaped contact surfaces (69, 70), in particular at least six linear-shped or strip-shaped contact surfaces (69, 70), between the clamping surfaces (57, 67, 68) and the outer surface (71) of the shank of the tap (6) is fixable in a force-fit manner.

14. Thread-cutting chuck according to one or more of the preceding claims, characterized in that at least one elastomer element is formed of an elastomer and / or of plastic with a modulus of elasticity of the elastomer and / or plastic between 0.05 GPa and 10 GPa.

15. Thread-cutting chuck according to one or more of the preceding claims, characterized in that at least one elastomer element is formed as a spring, in particular a disc spring and / or a spiral spring.