Fixing and coupling device for a rotary tool and machine tool having such a fixing and coupling device

Abstract

The present invention relates to a fixing and coupling device (6) for a rotary tool, the fixing and coupling device being configured for connection to a drive unit of a machine tool (1) having a rotary drive, the fixing and coupling device having a coupling shaft (14), a clamp (9) for receiving a tool bar, a clamping mechanism (13) for maintaining the clamp (9) in a clamped position when unloaded from the outside, a releasing mechanism (21) for applying a releasing force to the clamping mechanism (13) when the coupling shaft (14) stops, thereby moving the clamp (9) to a released position, and an operating mechanism (34) for actuating the releasing mechanism (21) by the user of the machine tool (1), particularly by hand force. In this way, a simple and feasible solution is provided for fixing and releasing a tool to and from the machine tool (1) without a separate tool.

Description

Technical Field

[0001] This invention relates to a fixing and coupling device for a rotary tool, the fixing and coupling device being configured for connection to a drive unit of a machine tool having a rotary drive, and to a machine tool having such a fixing and coupling device and a drive unit. The driving torque generated by the drive unit is transmitted to the fixing and coupling device (in which the rotary tool is fixed) connected to the drive unit, thereby placing the tool in rotation. The rotary tool is thus coupled to the drive unit via the fixing and coupling device. The rotary drive of the drive unit is typically an electric motor, but other drives, such as an internal combustion engine, are also conceivable.

[0002] This invention is described in conjunction with grinding machines, and especially with straight grinding wheels. However, it should be noted that the invention can be used regardless of the type of machine tool and the type of rotary tool connected to it. Therefore, the invention can also be used, for example, with polishing machines, circular saws, drilling machines, or milling machines.

[0003] Preferably, the machine tool is held by the user's hand. Furthermore, it is preferably designed for battery operation, grid operation, or a combination of both.

[0004] The rotation axis of the rotary drive of the preferred machine tool coincides with the rotation axis of the rotary tool, as is the case, for example, in the straight grinding wheel exemplified here.

[0005] The starting point of this invention is that rotary tools, exemplarily in this case, straight grinding tools, i.e., grinding tools, have a rod-shaped tool bar for connection to the fixing and coupling device of a machine tool. The tool bar is particularly cylindrical, but can also have a hexagonal, quadrilateral, or other particularly rotationally symmetrical shape in cross-section. Cylindrical tool bars are available by standard in different diameters, such as 3mm, 6mm, 8mm, or 1 / 4 inch. Background Technology

[0006] The use of clamps to receive and secure tool rods has long been known in the art. Here, "clamp" refers to a generally cylindrical sleeve for coaxially receiving a tool rod from its outer end, the circumferential surface of which can be pressed radially inward against and clamp the tool rod. For this purpose, the circumferential surface of the clamp preferably has one or more slots extending parallel to the longitudinal axis of the clamp and beginning at the outer end of the clamp. This forms one or more tongues, preferably of equal width, on the circumferential surface, which turn into a continuous, unslotted circumferential surface at their inner ends opposite the outer end of the clamp. These tongues can be pressed radially inward due to their elasticity and clamp the tool rod introduced into the clamp. Preferably, the outer diameter of the tool rod is equal to the inner diameter of the clamp, so that the tool rod can be introduced into the clamp without clearance and the clamp's tongues only need to be pressed slightly radially inward against the tool rod to clamp it. In this way, the circular motion of the rotary tool is also ensured when using the machine tool.

[0007] When we refer here and below to the “outer” end of each component, it always means the end of the clamp along the longitudinal axis of the machine tool, where the tool bar is received. Conversely, the “inner” end of a component refers to the end along the longitudinal axis of the machine tool opposite to the outer end. This also applies to concepts such as “outward” or “inward.” The outer end of the clamp thus also constitutes the outer end of the entire machine tool.

[0008] The clamp is preferably releasable or non-releasable, especially integral, but in any way torsionally connected at its inner end to the output shaft of the machine tool's drive unit, so that the torque of the drive unit can be transmitted through its output shaft to the clamp and the tool bar clamped therein, and thus to the rotary tool. The torsionally resistant connection between the clamp and the output shaft of the drive unit ensures that, during operation, the clamp remains fixedly connected to the output shaft as the drive unit rotates, and that both, i.e., the clamp and the output shaft, rotate together as a single unit.

[0009] The radial inward clamping of the jaws and the clamping of the tool lever are preferably achieved by the following method: the jaws have at least a segmental conical outer surface in the region of the jaws, which tapers towards the inner end of the jaws. The jaws are then inserted at their inner end into a jaw receiving portion, which can also be substantially cylindrical in shape and arranged coaxially with the jaws, wherein the jaws at their outer end of the jaw receiving portion can axially protrude beyond the end of the jaw receiving portion. The jaw receiving portion also has a conical surface on its inner surface, which tapers in the same direction and has the same slope as the conical surface of the jaws.

[0010] If the clamp is now moved axially inward relative to the clamp receiving portion, the clamp's tongues are radially pressed inward due to the wedge-like action of the two conical surfaces arranged relative to each other, which reduces the width of the slot extending between the tongues. As already described, the tool bar inserted into the clamp is thus clamped.

[0011] Clamps known in the prior art have external threads at their inner end, which are screwed into corresponding internal threads in the open end of the clamp receiving portion. Furthermore, the clamp has external hexagons on its section protruding beyond the axial direction of the clamp receiving portion, and the clamp receiving portion also has external hexagons or at least two parallel faces on its outer surface for holding an open-end wrench. Axial movement of the clamp relative to the clamp receiving portion toward its inner end is achieved by the user screwing the clamp into the clamp receiving portion with an open-end wrench while the tool handle is inserted, and then securing the clamp with another open-end wrench to prevent it from rotating together. One of the two open-end wrenches is unnecessary as long as the clamp or clamp receiving portion can be locked in other ways and thus prevented from rotating together.

[0012] However, this known method of securing the tool lever in the clamp is not satisfactory from the point of view of machine tool operating comfort, as it is quite time-consuming and requires a separate tool, namely at least one open-end wrench. However, practical experience shows that such a separate tool is often misused or at least not where the user needs it. Summary of the Invention

[0013] Therefore, the object of the present invention is to provide a simple and feasible solution for securing or removing a tool from a machine tool without the need for a separate tool.

[0014] This task is accomplished according to the invention by a fixing and coupling device as described in claim 1. Preferred modifications of the invention are the subject of the dependent claims.

[0015] The fixing and coupling device for rotary tools according to the invention is configured for connection to the drive unit of a machine tool having a rotary drive, the fixing and coupling device having components and sub-units as described below. It should be noted that these components and sub-units are not necessarily separate, that is, not necessarily non-overlapping. Rather, different components or sub-units can share various elements. In particular, each sub-unit can completely encompass each component.

[0016] The fixing and coupling device has a coupling shaft with a longitudinal axis, which can rotate about the longitudinal axis by a rotary drive when the fixing and coupling device is connected to the drive unit of the machine tool. Here, the coupling shaft is connected to the output shaft of the drive unit, especially to the motor shaft of an electric motor, in a torque-transmitting manner, wherein the connection is preferably coaxial, as in, for example, a straight grinding wheel. The connection between the output shaft and the coupling shaft can also be made by a transmission mechanism, such as a cylindrical gear transmission mechanism or a planetary gear transmission mechanism, wherein the latter arrangement can be offset between the output shaft and the coupling shaft. However, the connection can also be made such that the two shafts form a non-zero angle, especially a right angle, as in, for example, an angle grinder. The connection is then preferably made by a joint or bevel gear transmission mechanism, especially a conical gear transmission mechanism.

[0017] If we refer to a "rotating coupled shaft" below, this should mean that the coupled shaft rotates at a speed suitable for use with a machine tool equipped with a rotary tool, that is, at which speed the workpiece can be machined by the rotary tool. This speed is not necessarily constant; for example, different speed levels or speed ranges can be set in the drive unit for use with the machine tool. However, the smaller speed experienced by the coupled shaft when starting from a stopped state should not be considered part of the concept of a "rotating coupled shaft".

[0018] Furthermore, the fixing and coupling device has a clamp for releasably receiving, in particular, cylindrical tool rods. The clamp is movable between a clamped position and a released position by relative movement along the longitudinal axis relative to a clamp receiving portion that is torsionally and integrally connected to the coupling axis. In the clamped position, the tool rod is clamped in the clamp such that it is torsionally connected to the coupling axis and can rotate about the longitudinal axis, and in the released position, the tool rod can be removed from or inserted into the clamp. The operating principle of the clamp is essentially the same as that of the prior art clamps described above. However, unlike the prior art clamps, the relative movement of the clamp relative to the clamp receiving portion along the longitudinal axis according to the invention is preferably a purely linear or substantially linear movement, but not a helical movement. "Substantially linear movement" here refers to a movement that combines linear movement with slightly other movements, especially rotational movements.

[0019] Furthermore, the fixing and coupling device includes a clamping mechanism with clamps and a clamp receiving portion. The clamping mechanism is configured to maintain the clamp in a clamped position when not subjected to external load, to move the clamp from the clamped position to the released position when a releasing force is applied to the clamping mechanism from the outside, and to move the clamp from the released position to the clamped position when the releasing force is released. In addition to the clamps and clamp receiving portion, the clamping mechanism may also have a coupling shaft, allowing the clamping mechanism to be directly connected to the drive unit of the machine tool.

[0020] The clamping mechanism is designed to maintain the clamping position of the clamps when not subjected to external loads, thus enabling it to operate as an "autonomous unit" without requiring continuous contact with other external components to maintain the clamping position. Because maintaining the clamping position is crucial, especially during machine tool operation and thus during the rotation of the coupling shaft, such continuous contact between the clamping mechanism's components rotating with the coupling shaft and external, non-coupling components of the clamping device is detrimental and leads to heat generation and power loss due to friction, through which a significant force must then be transmitted to maintain the clamping position.

[0021] Furthermore, the fixing and coupling device has a release mechanism, and the coupling shaft can rotate relative to the release mechanism. That is, the release mechanism does not rotate with the coupling shaft when it rotates, but is arranged relatively stationary relative to the machine tool, although it may also have its own moving parts. The release mechanism is configured to apply a release force to the clamping mechanism when the coupling shaft is stopped during operation of the release mechanism.

[0022] Because the tool lever should only be released from the clamp when the coupling shaft is stopped for safety reasons, the following arrangement does not represent a disadvantage: that is, contact with the external components of the clamping mechanism, i.e. the release mechanism, is required to generate the release force.

[0023] Finally, the fixing and coupling device has an operating mechanism that can be operated by the machine tool user, especially by hand, and is configured to operate and terminate the operation of the release mechanism. By operating the operating mechanism, the user can thereby place the clamp in the loosened position via the release mechanism for tool changing and / or clamp changing, and place the clamp in the clamped position to fix the rotary tool and thereby use the machine tool.

[0024] The fixing or loosening of tools from the machine tool is thus accomplished simply by operating the operating mechanism, especially by manual force. Since the operating mechanism is a sub-unit of the fixing and coupling device and therefore part of the machine tool, no separate tool is required. Thus, the objective of the present invention is achieved.

[0025] In a preferred embodiment of the invention, the clamping mechanism has at least one pre-tensioned spring element for maintaining the clamping position of the clamp when not subjected to external load. This represents a simple structurally feasible solution for generating the force to maintain the clamping position without requiring continuous contact with other external components of the clamping mechanism.

[0026] Preferably, the entire clamping mechanism and coupling shaft rotate together, thus preventing bearing load during machine tool operation. However, it is also conceivable that the pre-tensioned spring element does not rotate together and is supported on one side, for example, on the housing of the fixing and coupling mechanism and on the other side on an axial bearing, wherein the spring force for maintaining the clamping position of the clamp is then transmitted through the axial bearing.

[0027] In a preferred variation of this implementation, the clamping mechanism is configured to pull the clamp into the clamp receiving portion by means of a restoring force generated by the pretension of at least one pretensioned spring element. This pulling then represents the required relative movement of the clamp along its longitudinal axis relative to the clamp receiving portion. This movement preferably occurs towards the inner end of the clamp, whereby the tongues arranged on the clamp are radially pressed inward and clamp the tool bar by the wedge action of two conical faces of the clamp or clamp receiving portion arranged between each other, as described above. In this way, substantially the same clamps and clamp receiving portions as in the prior art can be used, which reduces the cost of technically implementing the invention.

[0028] In a preferred embodiment of the last described variant, the clamping mechanism has a traction rod for transmitting tension from at least one pre-tensioned spring element to the clamp, and the clamp is releasably connected to the traction rod, in particular, via a threaded or bayonet connection. This results in the ability to use the same clamps as in the prior art, especially if known clamps, as described above, can be screwed into a clamp receiving portion and now instead screwed to the traction rod using threads provided for this purpose. Furthermore, in the case of a threaded connection between the clamp and the traction rod, the tension acting on the clamp can be steplessly adjusted via the threads. When using other connection techniques, such as bayonet connections, the necessary modifications to known clamps are also minimal. Moreover, this variant has the advantage that the clamps can be replaced individually, for example, in case of damage or when a rotary tool with a different rod diameter should be clamped.

[0029] In another preferred variant of the embodiment described last, at least one pre-tensioned spring element is at least one disc spring, preferably a stack of multiple disc springs. Because a single disc spring can generate very high spring force, this high spring force can be achieved, especially by using a stack of multiple disc springs, where the spring travel is multiplied by the number of disc springs in the stack. Such high spring force is also necessary to achieve a sufficiently firm and thus reliable clamping of the tool lever in the clamp.

[0030] In another preferred variant of the embodiment described last, the release mechanism is configured to apply a release force to the clamping mechanism when the coupling shaft stops, such that the release force counteracts the restoring force generated by the pretension of at least one pretensioned spring element. This represents a simple structurally feasible solution for generating the release force.

[0031] In another preferred embodiment of the invention, the clamping mechanism further includes an anti-release mechanism configured to prevent the clamping mechanism from being subjected to a release force while the coupling shaft is rotating. As already mentioned, the tool lever can only be released from the clamp when the coupling shaft is stopped for safety reasons. Release of the tool lever from the clamp while the coupling shaft is rotating could cause the rotary tool to uncontrollably separate from the machine tool, which possesses significant kinetic energy due to its rotation. This could lead to damage to the workpiece being machined, to the rotary tool itself, or to the machine tool, or in the most serious cases, to injury to the user of the machine tool, and therefore must be prevented. The anti-release mechanism thus precisely addresses this safety requirement.

[0032] In a preferred variation of this embodiment, the anti-loosening mechanism is arranged to resist torsion relative to the coupling shaft and has at least one centrifugal counterweight. The loosening mechanism is arranged such that, when the coupling shaft is stopped during operation of the loosening mechanism, a loosening force is applied to the clamping mechanism through contact, and this force is transmitted along the longitudinal axis between at least one first contact point on the at least one centrifugal counterweight and at least one second contact point on the loosening mechanism. The at least one centrifugal counterweight is pre-tensioned radially inward, and the at least one first contact point can move radially outward by centrifugal force when the coupling shaft rotates, making it impossible for contact to occur between the at least one first contact point and the at least one second contact point when the coupling shaft rotates during operation of the loosening mechanism, and thus preventing the transmission of the loosening force. Thus, the transmission of the loosening force from the loosening mechanism to the clamping mechanism during coupling shaft rotation is controlled solely by the centrifugal force that naturally occurs during coupling shaft rotation. The advantage of this technical implementation of the anti-loosening mechanism is that it can be used without, in particular, electrical or electronic, control mechanisms with sensors and / or actuators, but only with mechanical components, and is therefore reliable and maintenance-free.

[0033] In a variant of the embodiment described last, at least one centrifugal counterweight in the region of at least one first contact point and at least one release mechanism in the region of at least one second contact point have at least one protrusion and / or at least one recess relative to a plane perpendicular to the longitudinal axis, respectively. They are arranged such that when at least one centrifugal counterweight contacts and transmits the release force between at least one first contact point and at least one second contact point, and when the coupling shaft starts from the stopped state, it can move radially outward, thereby no longer being able to contact between at least one first contact point and at least one second contact point, and thus no longer being able to transmit the release force. This ensures that if the release mechanism is actuated, the actuation of the release mechanism ends when the coupling shaft starts. This ensures that reliable tool fixation is established when the clamp is in the released position when the coupling shaft starts. This must also be guaranteed for safety reasons, because otherwise, it could happen that the rotary tool uncontrollably separates from the machine tool when the coupling shaft rotates.

[0034] In another preferred embodiment of the invention, the operating mechanism is configured to convert the user-operated, coaxial rotational motion of the operating element into motion along the longitudinal axis for operating the release mechanism. In particular, the rotary handle used as the operating element can achieve a large angle of rotation, without requiring a large size or significant structural space on the machine tool, as it can be easily arranged around the fixing and coupling device and, in particular, coaxially with the longitudinal axis. The large angle of rotation also allows for a reduction in the torque required to operate the rotary handle, which the user must apply manually. Such rotational motion for operating the operating mechanism thereby improves operational comfort during tool changes.

[0035] In a preferred variation of the embodiment described last, the conversion from rotary motion to motion along the longitudinal axis is achieved via a wedge-shaped transmission mechanism. This represents a simple structurally feasible solution for achieving motion conversion. In particular, the wedge-shaped transmission mechanism can also be used to transmit force, allowing the rotational motion of the actuating element, with small torque over a large angular range, to be converted into motion along the longitudinal axis, with a smaller stroke range but correspondingly higher force.

[0036] In a preferred variant of the last described variation, the wedge drive mechanism has at least one groove having at least one section extending obliquely relative to a plane perpendicular to the longitudinal axis and at least one movable groove follower (Kulissenfolger) within the groove. Here, the groove is immovable relative to the machine tool, and the groove follower is rotatably arranged about the longitudinal axis, or vice versa. In this case, the wedge drive mechanism is achieved by the obliquely extending section of the groove combined with the groove follower, which is also moved along the longitudinal axis as it moves within the groove. The force transmission of the wedge drive mechanism can then be defined in a simple manner by selecting the inclination of the obliquely extending section of the groove.

[0037] In a variant that is an alternative to the last described variation, the wedge-shaped transmission mechanism has two surfaces facing each other along the longitudinal direction, at least one of which has a section extending obliquely relative to a plane perpendicular to the longitudinal axis. Here, exactly one of the two surfaces is rotatably arranged about the longitudinal axis and exactly one of the two surfaces is movably arranged along the longitudinal axis, and at least one rolling element, particularly at least one ball, is arranged between the two surfaces. The surface rotatable about the longitudinal axis and the surface movable along the longitudinal axis can be the same surface or can be different surfaces. In one structural embodiment, the two surfaces are preferably the axial end faces of two rings arranged coaxially with the longitudinal axis, wherein the rings are rigidly connected to an actuating element via the surface rotatable about the longitudinal axis and the rings are connected to a release mechanism via the surface movable along the longitudinal axis for actuating the release mechanism.

[0038] In this configuration, the wedge-shaped transmission mechanism is achieved by engaging at least one rolling element with an inclined section of at least one of the two surfaces. This causes a change in the axial distance between the two surfaces as the at least one rolling element rolls on the inclined section of one of the surfaces. Subsequently, the rotation of the rotatable surfaces of the two surfaces causes the movable surfaces along the longitudinal axis of the two surfaces to move axially accordingly via the wedge-shaped transmission mechanism. The force transmission of the wedge-shaped transmission mechanism can then be easily defined by selecting the inclination of the inclined section of at least one of the two surfaces.

[0039] Compared to the previously described variant with a groove and a groove follower, this variant has the advantage that the two-sided components, specifically the two rings, can be manufactured separately and thus made of a hard material, particularly steel. In contrast, the material of the grooved component can be predetermined due to the structure of the fixing and coupling devices. For example, this component must be made of aluminum for weight reasons. However, aluminum is significantly softer than steel, and the movement of the groove follower, which should be made of steel for strength reasons, may cause it to press inward, widen, or damage the groove. This risk does not exist if both components forming the wedge-shaped transmission mechanism—as in this variant, with both sides and at least one rolling element—are made of steel.

[0040] Furthermore, the present invention relates to a machine tool having a drive unit and a fixing and coupling device according to the invention connected to the drive unit.

[0041] In a preferred embodiment, the machine tool according to the invention includes a sensor, particularly a position sensor, and a drive control mechanism, wherein the sensor is configured to detect manipulation of the release mechanism, and the drive control mechanism is configured to control the drive unit to prevent the coupling shaft from starting from a stopped state when the release mechanism is manipulated. The sensor here specifically detects the axial position of the assembly of the release mechanism that applies a release force to the clamping mechanism and detects manipulation of the release mechanism therefrom. This represents an alternative solution to the problem of preventing the coupling shaft from starting from a stopped state for safety reasons when the release mechanism is manipulated. The solution described above is implemented purely mechanically by at least one protrusion and / or at least one recess on at least one centrifugal counterweight and on the release mechanism, while this solution uses a preferred electrical or electronic drive control mechanism in the machine tool. This is particularly cost-effective compared to mechanical solutions when the existing drive control mechanism only needs to be additionally equipped with the functions according to this embodiment.

[0042] In one alternative to the variant described last, the drive unit includes an electric motor, a current sensor for detecting the motor current, and a drive control mechanism configured to detect the actuation of the release mechanism from the detection of the motor current when the coupling shaft starts from a stopped state, and thus control the drive unit to prevent the coupling shaft from starting from a stopped state when the release mechanism is actuated. This represents another alternative solution to the problem of preventing the coupling shaft from starting from a stopped state for safety reasons when the release mechanism is actuated. This solution utilizes the fact that when the release mechanism is actuated by a release force, high friction is generated between the release mechanism and the clamping mechanism when the coupling shaft starts, resulting in a large mechanical resistance acting on the coupling shaft, which must be overcome by the large electrical power of the electric motor. This, in turn, increases the motor current, which can be detected by the current sensor. The advantages of this variant are similar to those of the variant described above, which provides the following additional advantages: the current sensor can be directly integrated into the drive control mechanism without requiring additional structural space and eliminating the need for cable laying between the drive control mechanism, which is typically located in the drive unit, and the sensor in the fixed and coupled device. Attached Figure Description

[0043] Other advantages, features and applicable solutions of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings.

[0044] Here: Figure 1 The machine tool according to the invention is shown from above; Figure 2 An exploded perspective view illustrates a first embodiment of the fixing and coupling device according to the invention; Figure 3 The first embodiment is shown in a side view, in which the rotating handle and the neck bearing are removed; Figure 4 A cross-sectional view of the first embodiment is shown when the coupling shaft is stopped; Figure 5 A cross-sectional view of the first embodiment is shown during the rotation of the coupling shaft; Figure 6 The first embodiment of the anti-loosening mechanism is shown in the case where the coupling shaft is stopped; Figure 7 The first embodiment of the anti-loosening mechanism is shown when the coupling shaft rotates; Figure 8 The diagram illustrates an alternative embodiment of the anti-loosening mechanism of the first embodiment, showing the situation when the coupling shaft stops. Figure 9 The spiral ring of the operating mechanism of the first embodiment is shown. Figure 10 The operating mechanism of the first embodiment is shown; Figure 11 A second embodiment of the fixing and coupling device according to the invention is shown in a perspective exploded view. Detailed Implementation

[0045] Figure 1 Here, a machine tool 1 according to the invention is shown as an example of a straight grinding wheel. Figures 2 to 10 A first embodiment of the fixing and coupling device 6 according to the present invention is shown and will therefore be described below together.

[0046] Machine tool 1, as a main component, has a drive unit 2 with an electric motor (not shown) and a fixing and coupling device 6. Because machine tool 1 is a straight grinding wheel, all components of the power transmission system are arranged along the longitudinal axis of machine tool 1.

[0047] The drive unit 2 has a housing 3, a switch 4 for turning the electric motor on and off, and a cable 5 for the power connector of the machine tool 1. Other components of the drive unit 2, such as the transmission mechanism, fan, or power supply, are irrelevant to the present invention and are therefore not described.

[0048] The fixing and coupling device 6 is flanged to the end side of the drive unit 2 and forms the neck of the machine tool 1. The housing of the fixing and coupling device 6 is formed by a continuous neck bearing 7, which has a flange 27, which is secured by bolts 30 and corresponding screw-in openings 28 (see...). Figure 2 and 3 It is screwed onto the cover 29 on the end side of the drive unit 2.

[0049] The neck bearing 7 also has a slightly conical, smaller diameter section, which is surrounded by a rotating handle 8 that is also slightly conical in the outer section and cylindrical in the inner section. At the outer end of the rotating handle 8, clamps 9 and clamp receiving parts 10 extend beyond the neck bearing 7 and the rotating handle 8. These components, apart from the coupling shaft 14 and other components, are part of the clamping mechanism 13 (see...). Figures 2 to 5 The clamping mechanism 13 is arranged inside the journal bearing 7 and will be described in detail below. The clamping mechanism 13, except for the aforementioned protruding portion, is protected by a sleeve 11 to prevent dust and foreign matter from entering. This sleeve is screwed into the threads on the outer end of the journal bearing 7 and encloses the journal bearing (see...). Figure 4 and 5 ).

[0050] The clamp 9 is used to receive a cylindrical tool bar (not shown) in this embodiment. The clamp 9 has multiple slots on its outer end parallel to the longitudinal axis of the machine tool 1, thereby forming multiple tongues. The clamp 9 has a section with a conical outer surface, which is fitted into a corresponding section of the clamp receiving portion 10, which has a conical inner surface. If the clamp 9 moves axially toward the clamp receiving portion 10, the two conical surfaces are pushed together. This causes the tongues of the clamp 9 to be radially pressed inward, thereby clamping the tool bar inserted into the clamp 9. The clamp 9 has the same operating principle as clamps from the prior art. Refer to the above description of such known clamps for this purpose.

[0051] The clamp 9 has a bayonet socket 12 at its inner end, by means of which the clamp can be engaged into a pin 35 by a combination of plugging and rotational movement. The pin passes through a radial hole at the end of the traction rod 37 and protrudes beyond the hole on both sides (see...). Figure 4 Or (the same in the second implementation) Figure 11 The clamp 9 is coaxially and torsionally connected to the traction rod 37 via the bayonet socket 12.

[0052] The bayonet socket 12 is configured such that a slight overhang must be overcome in order to engage the clamp 9 into the pin 35 or remove the clamp from the pin, thereby preventing the clamp 9 from accidentally dislodging from the clamp receiving part 10 when the clamp 9 is clamped and thus even under tensile stress, especially during the operation of the machine tool 1.

[0053] To prevent the clamp 9 from rotating and falling out of the clamp receiving mechanism 10 when it is in the released state and not under tensile stress, it is slightly pre-tensioned outward by a spring element, specifically the elastomeric element 36 in this embodiment. The elastomeric element 36 is disposed in the closed end inside the clamp receiving portion 10. The restoring force of the elastomeric element pushes the clamp 9 away from the clamp receiving portion 10 and thereby away from the pin 35, thus keeping the bayonet connection in the closed state. However, the restoring force of the elastomeric element 36 can be easily overcome by hand by the user of the machine tool 1, for example, to change the clamp without tools when a clamp with a different inner diameter is needed.

[0054] Clamp 9, clamp receiving part 10, coupling shaft 14 and traction rod 37 are parts of clamping mechanism 13 (see Figures 2 to 5 The clamp receiving portion 10 is connected to the coupling shaft 14 and forms its outer end. The connection between the clamp receiving portion 10 and the coupling shaft 14 can be integral, seamless, or material-locked. Furthermore, the coupling shaft 14 is made as a hollow shaft in its outer portion so as to receive the traction rod 37 axially within it.

[0055] The coupling shaft 14 is connected at its inner end by a wedge via a longitudinal groove 20 (see...). Figure 2 ) and wedge 39 (see Figure 11 The motor (using the same wedge connection as in the second embodiment) is torque-transmittingly connected to the output shaft (not shown) of the electric motor in the drive unit 2. The output shaft of the electric motor is supported in the drive unit 2 by a rolling bearing 31, which is sealed by a sealing ring 32 and secured by an anti-loosening ring 33.

[0056] The clamping mechanism 13 keeps the clamp 9 clamped even without external force, so as to hold the tool rod. For this purpose, the clamping mechanism 13 also has a disc spring assembly 15 with (twenty-four in this embodiment) disc springs arranged coaxially around the coupling shaft 14 as a stack. The disc spring assembly 15 is supported at its outer end by a balance ring 18 on an anti-loosening ring 62, which is inserted into a slot on the coupling shaft 14. Furthermore, the balance ring is adjusted so that any potential imbalance on the coupling shaft 14, particularly caused by the other components of the clamping mechanism 13, is compensated as much as possible. The disc spring assembly 15 is supported at its inner end on the outer end of a centrifugal counterweight support 41 of an anti-loosening mechanism 16, which will be described in detail below. The centrifugal counterweight support 41 is also arranged coaxially on the coupling shaft 14 with an internal bore. Pin 38 is inserted through opposing radial openings 46 in centrifugal counterweight support 41, which passes through an elongated hole 60 in coupling shaft 14 within a drilled hole inside centrifugal counterweight support 41, thereby connecting centrifugal counterweight support 41 and coupling shaft 14 in a torsion-resistant but axially movable manner. Furthermore, pin 38 is inserted radially at its innermost point through a radial drilled hole in traction rod 37, thus forming a rigid connection between centrifugal counterweight support 41 and traction rod 37. Traction rod 37 is thus pulled inward by a restoring force against the prestress of disc spring assembly 15, thereby maintaining the clamping position of clamp 9.

[0057] The clamping mechanism 13 thus functions as an “autonomous unit” due to the prestress of the disc spring assembly 15, which should mean that it maintains the clamping position of the clamp 9 in particular without the action of external forces when it rotates together with the coupling shaft 14.

[0058] The clamping mechanism 13 is supported radially outward toward the inner side of the journal bearing 7 by the rolling bearing 19. The rolling bearing 19 is arranged on the coupling shaft 14 between a radial shoulder at the inner end of the clamp receiving portion 10 and the anti-loosening ring 62 already described. Outside the rolling bearing 19, a felt washer 17 is also arranged on the coupling shaft 14. The felt washer serves as a dustproof element to prevent, for example, abrasive debris from being squeezed in from the outside through the sheath 11, which could contaminate and damage the rolling bearing 19 and the other internal components of the journal bearing 7.

[0059] For tool changing, a feasible solution must be provided on machine tool 1 to switch clamping mechanism 13 from its clamped position to its released position, so as to open clamp 9 and allow removal or insertion of tool bar. Release mechanism 21 and operating mechanism 34 serve this purpose, and the operator of machine tool 1 can operate release mechanism 21 via the operating mechanism. The release mechanism and operating mechanism will be described in detail below.

[0060] The operating mechanism 34 has a rotary handle 8 as an operating element for the user of the machine tool 1. This rotary handle, due to its length, can be fully grasped and rotated by the user with one hand, while the user grips the machine tool 1 at the drive unit 2 with the other hand. In this embodiment, when changing tools, the user rotates the rotary handle 8, for example, by rotating it counterclockwise towards the outward end to operate the release mechanism 21, and by rotating it clockwise to end operation of the release mechanism 21. However, rotation in opposite directions is also possible.

[0061] The rotary handle 8 has a section with a larger diameter at its inner end. Radially, between this section and the journal bearing 7, a first helical ring 50, a second helical ring 51, and an axial bearing 54 are arranged coaxially with the longitudinal axis of the machine tool 1, forming the main components of the operating mechanism 34. The axial bearing 54 supports the reaction force generated by the operating mechanism 34 relative to the journal bearing 7, acting inward, i.e., toward the drive unit 2. The components of the operating mechanism 34 are particularly... Figure 9 and 10 It is shown in detail in the text.

[0062] The first spiral ring 50 is rigidly connected to the rotating handle 8 by a radially outward-pointing pin 53 and is thus rotatably but not axially movable relative to the neck bearing 7. Alternatively, bolts can be used instead of the pin 53. The second spiral ring 51 has a radially inward-pointing pin 25, which passes through an elongated hole 61 in the neck bearing 7 inside the second spiral ring 51 and is thus non-rotatably but axially movable relative to the neck bearing 7.

[0063] The first and second spiral rings 50 and 51 are manufactured with identical structures in this embodiment, which reduces the development and manufacturing costs of the fixing and coupling device 6. The spiral rings 50 and 51 each have multiple (three in this embodiment) ball raceways 57 of equal length on their opposing end faces. A ball 52 arranged between the two spiral rings 50 and 51 can roll simultaneously on two opposing ball raceways 57 on either the first or second spiral ring 50 or 51. A first locking notch 58, in the form of a recess in the ball raceway 57, is arranged at one end of each ball raceway 57, and a second locking notch 59, also in the form of a recess in the ball raceway 57, is arranged at the other end of each ball raceway 57, wherein the first locking notch 58 is deeper than the second locking notch 59. The ball raceways 57 are of equal length and are thus evenly distributed within the periphery of the ends of the two spiral rings 50, 51, such that either all balls 52 are simultaneously in the first locking notch 58, or all balls 52 are simultaneously in the second locking notch 59, or all balls 52 are simultaneously in corresponding positions on the ball raceways 57. The stable positions of the balls 52 in the first or second locking notches 58, 59 create the first or second locking position of the operating mechanism 34. The two locking positions correspond to the two ends of the rotational movement of the handle 8, with the first locking position corresponding to the rest position, i.e., the unoperated position, and the second locking position corresponding to the fully operated position of the operating mechanism 34. As in Figure 9 As can be seen, the transition zone between the corresponding first locking notch 58 of a ball raceway 57 and the second locking notch 59 of the adjacent ball raceway 57 is formed by an elevated area in between and by a sharp slope, making it impossible for the ball 52 to go out in this direction.

[0064] The ball raceway 57 is inclined relative to a plane perpendicular to the longitudinal axis of the machine tool 1, for example, by 2 or 3 degrees, and in this embodiment has a constant inclination. Therefore, the opposing ball raceways 57 on the first or second spiral rings 50, 51 are parallel to each other. If the first spiral ring 50 is now rotated counterclockwise by rotating the handle 8 and pin 53, each ball 52 is first simultaneously pressed out from the two first locking notches 58 on the two spiral rings 50, 51, thereby passing the first locking position and thus indicating to the user, through tactile feedback, that it has left the stationary position. Then, each ball 52 rolls on the ball raceway 57 on the first and second spiral rings 50, 51 respectively, but only the first spiral ring 50 rotates. (As can be seen by...) Figure 10As can be seen, each ball 52 moves clockwise relative to the first spiral ring 50 and counterclockwise relative to the second spiral ring 51, wherein the axial extension of the two spiral rings 50, 51 at the two contact points with the ball 52 is always increased due to the inclined arrangement of the two ball raceways 57. Since the first spiral ring 50 cannot move axially because it is supported by the axial bearing 54, the second spiral ring 51 moves outward instead. At the end of the rotation of the rotating handle 8 (approximately 210 degrees in this embodiment), each ball 52 on the two spiral rings 50, 51 engages in the corresponding second locking notch 59, thereby indicating to the user that the second locking position has been reached and the operating mechanism 34 is fully operated.

[0065] In an alternative embodiment (not shown), the rotating handle 8 can be designed such that the previously described rotational motion ends after 120 degrees and the ball 52 engages in the corresponding second locking notch 59.

[0066] In another alternative implementation (also not shown), the slope of the ball raceway 57 can be configured variably. This allows for adjustment or reduction of the operating force.

[0067] During the axial movement of the second spiral ring 51, the pin 25 also moves outward in the elongated hole 61 in the neck bearing 7, thereby causing the ring 24 of the releasing mechanism 21 and the pressure-bearing member 22 rigidly connected to it to also move outward. The outer end face of the pressure-bearing member 22 then... Figure 4 The inner end face of the centrifugal counterweight 40 of the anti-releasing mechanism 16 is visible in the image. As described above, the inner end face overcomes the restoring force generated by the pre-tensioned disc spring 15, pushes the traction rod 37 outward, and thereby relieves stress on the clamp 9, thus enabling tool changing.

[0068] The bearing member 22 has a continuous triangular opening 26 near its outer end on its cylindrical portion, but this opening is only for the purpose of simplifying the installation of the bearing member 22 and centering it.

[0069] As the operating mechanism 34 moves from the first locking position to the second locking position, the coil spring 23 is simultaneously tensioned. The coil spring 23 is supported at its outer end on a ring 63 that is fixedly pressed into the journal bearing 7, and at its inner end on a ring 24 of the release mechanism 21 (see...). Figure 4 ).

[0070] The opposite movement of the operating mechanism 34 from the second locking position to the first locking position is similar to the movement described above, but only in the opposite direction, and causes the second spiral ring 51 to move inward again. As a result, the pressure acting on the centrifugal counterweight 40 through the pressure member 22 is released again and the clamp 9 is clamped again by the clamping mechanism 13, thus ending the tool change.

[0071] Because the coil spring 23 is also relaxed during this reverse movement, pressing the second coil ring 61 inward, the user only needs to move in the opposite direction past the second locking position and release the rotary handle 8. The subsequent reverse movement is then performed automatically by the relaxation of the coil spring 23. At the end of this automatic reverse movement of the operating mechanism 34, the ball 52 also automatically engages into the first locking notch 58, thus bringing the operating mechanism 34 back to a stationary position, a fact indicated to the user by the "engagement" of the rotary handle 8. This further improves the ease of use of the machine tool 1.

[0072] As explained above, clamp 9 is only stress-relieved when coupling shaft 14 is stopped for safety reasons. To prevent clamp 9 from being stress-relieved while coupling shaft 14 is rotating, an anti-release mechanism 16 is provided. Figures 6 to 8 It is shown in detail in the text.

[0073] The anti-loosening mechanism 16 has a plurality of centrifugal counterweights 40 (three in this embodiment), which are rotatably arranged on the inner end side of the centrifugal counterweight support 41 via rotary bearings 45, each about an axis extending parallel to the coupling shaft 14. The centrifugal counterweight support 41 has two radially opposed openings 46, through which pins 38, as already described, pass and are connected radially inward to the traction rod 37.

[0074] The centrifugal weight 40 is pre-tensioned radially inward by a common, encircling spring coil 42 guided in a groove 47 of the centrifugal weight 40 (see...). Figure 4 , 6 And 8). If the coupling shaft 14 rotates, the centrifugal counterweight 40 moves radially outward around the rotary bearing 45 by the centrifugal force that then takes effect (see 8). Figure 5 and 7 If the coupling shaft 14 stops again, the centrifugal counterweight 40 is again compressed radially inward through the spring coil 42.

[0075] The outer end face of the pressure-bearing member 22 is arranged such that it contacts the inner end face of the centrifugal counterweight 40 in a radially inward region when the centrifugal counterweight 40 is in its rest position, i.e., when it is not moving outward by centrifugal force. Then, in this position of the centrifugal counterweight 40, the pressure-bearing member 22 can transmit the releasing force to the centrifugal counterweight 40 and through the centrifugal counterweight support 41 and the traction rod 37 to relieve stress on the clamp 9. However, the radius of the contact surface between the pressure-bearing member 22 and the centrifugal counterweight 40 is so small that contact can no longer occur between the pressure-bearing member 22 and the centrifugal counterweight 40 when the centrifugal counterweight 40 moves outward by centrifugal force. If the operating mechanism 34 is operated while the coupling shaft 14 is rotating, the outer end face of the pressure-bearing member 22 is thus "push-away." This prevents the clamp 9 from being relieved of stress while the coupling shaft 14 is rotating.

[0076] Figure 8 A variation of the anti-loosening mechanism 16 is also shown, in which each centrifugal weight 40 has a protrusion 48 on its radially inner edge in the contact area with the pressure member 22, i.e., on its inner end face. This protrusion is preferably lentil-shaped in cross-section. In this variation, the outer end face of the pressure member 22 correspondingly has helical grooves (not shown). These grooves engage circumferentially with the protrusions 48 during the relative rotational movement between the centrifugal weight 40 and the pressure member 22, causing the centrifugal weight 40 to then move outward as well, thus eliminating contact between the pressure member 22 and the centrifugal weight 14.

[0077] As a result, if the machine tool 1 is engaged with the release mechanism 21 activated and the coupling shaft 14 begins to rotate, the pressure member 22 is "push-out" again, thus canceling the release force acting on the clamping mechanism 13 and causing the clamp 9 to firmly clamp the tool bar again. This avoids the situation where the clamp 9 is not clamped when the release mechanism 21 is activated during the start of the coupling shaft 14.

[0078] In this situation, the anti-loosening mechanism 16 cannot perform the function described above because the friction generated by the pressure exerted on the centrifugal counterweight 40 by the pressure member 22 will prevent the centrifugal counterweight 40 from moving radially outward, and in addition, the small rotational speed at the start of the coupling shaft 14 will not generate a sufficiently large centrifugal force.

[0079] However, as described above, as an alternative to this variant, the starting of the coupling shaft 14 can be completely prevented, especially by means of a position sensor or by monitoring the motor current of the electric motor in the drive unit 2, even when the release mechanism 21 is actuated.

[0080] Figure 11A second embodiment of the fixing and coupling device 6 according to the present invention is shown. This embodiment is different from that according to... Figures 2 to 10 The main difference in the first implementation lies in the other structures of the operating mechanism 34.

[0081] In this second embodiment, the rotational movement of the handle 8 is converted into axial movement not through two helical rings, but through a groove control mechanism. For this purpose, the neck bearing 7 has multiple (three in this embodiment) grooves 56, which are constructed as elongated holes. A radially arranged pin (or bolt, alternatively a groove follower) 25 is movably arranged in each groove 56. Rollers 55 are also arranged around each pin 25, rolling within the groove 56 to reduce friction between the groove follower and the groove 56. The pin 25 is fixedly connected to the rotating handle 8 at its radially outer end and similarly fixedly connected to the ring 24 of the release mechanism 21 at its radially inner end in a corresponding opening in the ring.

[0082] Each slide 56 has a sharply curved section at at least one end, through which a first locking position is achieved, similar to the situation described above in conjunction with the first embodiment. Adjoining the curved section is a longer section that is inclined relative to a plane perpendicular to the longitudinal axis of the machine tool 1. If the pin 25 moves along this inclined section of the slide 56 by the roller 55, the unit consisting of the rotating handle 8 and the ring 24 moves outward simultaneously due to the wedge action of the slide control mechanism. The inclination of the inclined section of the slide 56 can be variable so that the user can more easily overcome the rising spring force of the clamping mechanism 13 against the rotational movement of the handle 8. At the other end of the slide 56, a section is arranged for achieving a second locking position. This second locking position is achieved by the inclination of the slide 56 changing in another direction in this region, for example, becoming negative.

[0083] The slide 56 can also have a section that extends substantially parallel to the longitudinal axis, thus requiring sequential pushing and rotating movements (or vice versa) to operate the operating mechanism 34. This is to improve safety during the operation of the machine tool 1, as two separate motion processes are required to release the tool.

[0084] Unlike the first embodiment, in this case, the rotating handle 8 also moves outwards, but this does not interfere with the operation of the operating mechanism 34 due to the small axial travel. On the contrary, this even provides the advantage that the first locking position can be achieved by engaging the rotating handle 8 in the first axial position. For this purpose, a locking ring 64 made of round metal wire is provided, which is inserted into a groove (not shown) in the radially inner surface of the handle 8 and can simultaneously engage in a groove 65 on the radially outer surface of the bearing 7 in the first locking position. A second groove parallel to the aforementioned groove can also be provided on the radially outer surface of the bearing 7 for a corresponding second locking position. During the movement of the handle 8 between the first and second locking positions, the locking ring 64 is further pressed radially outwards into the groove of the handle 8, which is correspondingly deeper for this purpose.

[0085] A pressure-bearing member 22 is formed at the outer end of the ring 24 of the release mechanism 21. This pressure-bearing member is pressed against the centrifugal counterweight 40 of the anti-release mechanism 16 in the manner described above in conjunction with the first embodiment when the coupling shaft 14 stops. Unlike the first embodiment, in this case, the ring 24 and thus the pressure-bearing member 22 also rotate together during its axial movement, but this does not adversely affect the force transmission on the centrifugal counterweight 40.

[0086] Furthermore, in the second embodiment, the anti-loosening mechanism 16 differs slightly from that in the first embodiment. Therefore, here the centrifugal weight 40 is axially positioned entirely within the centrifugal weight support 41, and is prevented from falling out by an anti-loosening ring 44 on the inner side of the centrifugal weight support 41. The radially inward pretensioning of the centrifugal weight 40 is not accomplished by a common, encircling spring coil, but rather individually by small helical springs 43 for each centrifugal weight 40, which are radially outwardly supported on the circumference of the centrifugal weight support 41 and radially inwardly supported in the blind holes 49 of the corresponding centrifugal weight 40. However, the operating principle of the anti-loosening mechanism 16 in the second embodiment is the same as that in the first embodiment.

[0087] List of reference numerals in the attached diagram: 1. Machine Tool 2 drive units 3. Shell 4 Switches 5. Cables 6. Fixing and coupling device 7-Neck Bearing 8. Rotary handle 9 clamps 10. Clamp receiving section 11 Sheath 12-bayonet socket 13 Clamping mechanism 14 Coupled Axes 15 Disc Spring Assembly 16 Anti-loosening mechanism 17 Felt Washers 18. Balance ring 19 Rolling bearings 20 Longitudinal grooves 21. Loosening mechanism 22 Pressure-bearing components 23. Coil spring 24 rings 25 sales 26. The opening of the triangle 27. Flange of the neck bearing 28 Bolt opening 29. Cover of the drive unit 30 bolts 31 Rolling bearings 32 Sealing ring 33 Anti-loosening ring 34. Control mechanism 35 Pins for bayonet sockets 36 Elastomer Components 37. Towing bar 38 sales 39 Wedges 40 Centrifugal counterweight 41 Centrifugal counterweight support 42 Spring Coils 43. Coil spring 44 Anti-loosening ring 45 Rotary bearings used for centrifugal counterweights 46 Openings for pins 47. Groove for spring coils 48. The protrusion on the centrifugal counterweight 49 Blind Holes 50 First Helical Ring 51 Second Helical Ring 52 balls 53 sales 54 Axial bearings 55 rollers 56 Slides 57 Ball Track 58 First card lock notch 59 Second Lock Notch 60. Long hole in the coupling shaft 61. Long bore in the journal bearing 62 Anti-loosening ring 63. Ring in the neck bearing 64 Clamping Ring 65. Groove in the neck bearing

Claims

1. A fixing and coupling device (6) for a rotary tool, the fixing and coupling device being configured for connection to a drive unit (2) of a machine tool (1) having a rotary driver, the fixing and coupling device having: - A coupling shaft (14) having a longitudinal axis, wherein the coupling shaft (14) is capable of rotating about the longitudinal axis by a rotary drive when the fixing and coupling device (6) is connected to the drive unit (2) of the machine tool (1). - A clamp (9) for releasably receiving, in particular, cylindrical tool rods, the clamp being movable between a clamping position and a releasing position by relative movement along a longitudinal axis relative to a clamp receiving portion (10) that is torsionally and particularly integrally connected to a coupling shaft (14), wherein in the clamping position the tool rod is clamped in the clamp (9) such that the tool rod is torsionally connected to the coupling shaft (14) and is rotatable about the longitudinal axis, and in the releasing position the tool rod can be removed from the clamp (9) or can be inserted into the clamp (9). - Clamping mechanism (13), which has clamps (9) and clamp receiving part (10) and is configured to maintain the clamping position of the clamps (9) in a state where they are not subjected to external load, to move the clamps (9) from the clamping position to the loosening position when a loosening force is applied to the clamping mechanism (13) from the outside, and to move the clamps (9) from the loosening position to the clamping position when the loosening force is released. -Release mechanism (21), the coupling shaft (14) is rotatable relative to the release mechanism and the release mechanism is configured to apply a release force to the clamping mechanism (13) when the coupling shaft (14) is stopped when the release mechanism (21) is operated. - Operating mechanism (34), which can be operated by the user of the machine tool (1) especially by hand and is set to operate the release mechanism (21) and end the operation of the release mechanism (21).

2. The fixing and coupling device (6) according to claim 1, characterized in that, The clamping mechanism (13) has at least one pre-tensioned spring element (15) for maintaining the clamping position of the clamp (9) in a state where it is not subjected to external load.

3. The fixing and coupling device (6) according to claim 2, characterized in that, The clamping mechanism (13) is configured to pull the clamp (9) into the clamp receiving part (10) by means of the restoring force generated by the pretension of at least one pretensioned spring element (15).

4. The fixing and coupling device (6) according to claim 3, characterized in that, The clamping mechanism (13) has a traction rod (37) for transmitting tension from at least one pre-tensioned spring element (15) to the clamp (9), and the clamp (9) is releasably connected to the traction rod (37) in particular by means of a threaded connection or a bayonet connection (12, 35).

5. The fixing and coupling device (6) according to any one of claims 2 to 4, characterized in that, The at least one pre-tensioned spring element (15) is at least one disc spring, preferably a stack of multiple disc springs.

6. The fixing and coupling device (6) according to any one of claims 2 to 5, characterized in that, The release mechanism (21) is configured to apply a release force to the clamping mechanism (13) when the coupling shaft (14) is stopped, such that the release force counteracts the restoring force generated by the pretension of at least one pretensioned spring element (15).

7. The fixing and coupling device (6) according to any one of the preceding claims, characterized in that, The clamping mechanism (13) also has an anti-loosening mechanism (16) which is configured to prevent the clamping mechanism (13) from being subjected to a loosening force when the coupling shaft (14) rotates.

8. The fixing and coupling device (6) according to claim 7, characterized in that, The anti-loosening mechanism (16) is arranged torsionally relative to the coupling shaft (14) and has at least one centrifugal counterweight (40), wherein the loosening mechanism (21) is arranged such that when the coupling shaft (14) is stopped when the loosening mechanism (21) is operated, a loosening force is applied to the clamping mechanism (13) by contact and the loosening force is transmitted between at least one first contact point on at least one centrifugal counterweight (40) and at least one second contact point on the loosening mechanism (21) along the longitudinal axis, wherein the at least one centrifugal counterweight (40) is pre-tensioned radially inward, and the at least one first contact point is able to move radially outward by centrifugal force when the coupling shaft (14) rotates, so that when the coupling shaft (14) is rotated when the loosening mechanism (21) is operated, it is impossible for contact to occur between the at least one first contact point and the at least one second contact point and thus it is also impossible for the loosening force to be transmitted.

9. The fixing and coupling device (6) according to claim 8, characterized in that, The at least one centrifugal counterweight (40) has at least one protrusion (48) and / or at least one recess in the region of at least one first contact point and in the region of at least one second contact point, respectively, relative to a plane perpendicular to the longitudinal axis. The at least one protrusion and / or at least one recess are arranged such that when the at least one centrifugal counterweight (40) is in contact between at least one first contact point and at least one second contact point and transmits the release force, and when the coupling shaft (14) is started from the stopped state, it can move radially outward, thereby no longer being able to make contact between the at least one first contact point and at least one second contact point and thus no longer being able to transmit the release force.

10. The fixing and coupling device (6) according to any one of the preceding claims, characterized in that, The operating mechanism (34) is configured to convert the rotational motion of the operating element (8) coaxial with the longitudinal axis, performed by the user, into motion along the longitudinal axis for operating the release mechanism (21).

11. The fixing and coupling device (6) according to claim 10, characterized in that, The conversion from rotary motion to motion along the longitudinal axis is achieved through a wedge-shaped transmission mechanism (50-52; 25, 55, 56).

12. The fixing and coupling device (6) according to claim 11, characterized in that, The wedge-shaped transmission mechanism (25, 55, 56) has at least one groove (56) having at least one section extending obliquely relative to a plane perpendicular to the longitudinal axis and at least one groove follower (25, 55) movable in the groove (56), wherein the groove is immovable relative to the machine tool (1) and the groove follower (25, 55) is rotatably arranged about the longitudinal axis or vice versa.

13. The fixing and coupling device (6) according to claim 11, characterized in that, The wedge-shaped transmission mechanism (50-52) has two surfaces (57-59) facing each other along the longitudinal direction, at least one of the two surfaces having a section (57) extending obliquely relative to a plane perpendicular to the longitudinal axis, wherein exactly one of the two surfaces (57-59) is rotatably arranged about the longitudinal axis and exactly one of the two surfaces (57-59) is movably arranged along the longitudinal axis, and wherein at least one rolling element, in particular at least one ball (52), is arranged between the two surfaces (57-59).

14. A machine tool (1) having a drive unit (2) and a fixing and coupling device (6) according to any one of the preceding claims connected to the drive unit (2).

15. The machine tool (1) according to claim 14, characterized in that... Sensors, particularly position sensors, and a drive control mechanism, wherein the sensors are configured to detect manipulation of the release mechanism (21), and the drive control mechanism is configured to control the drive unit (2) to prevent the coupling shaft (14) from starting from a stopped state when the release mechanism (21) is manipulated.

16. The machine tool (1) according to claim 14, characterized in that, The drive unit (2) has an electric motor, a current sensor for detecting motor current, and a drive control mechanism configured to detect the manipulation of the release mechanism (21) from the detection of motor current when the coupling shaft (14) starts from the stop state and control the drive unit (2) thereby preventing the coupling shaft (14) from starting from the stop state when the release mechanism (21) is manipulated.

Images