EP1597023B1 - Fastening device and associated tool - Google Patents

Abstract

In order in fast clamping of a tool to a machine tool to provide a small amount of play between the tool ( 2 ) and the fastening device ( 1 ) in a rest position and/or in operation, there is proposed a fastening device having at least one projection of a closure means which can be actuated without the use of a tool and with which the fastening device, wherein in the closed position the projection ( 410 ) of the fastening device engages over an associated closure surface ( 220 ) of the tool and the tool body is axially secured and held non-rotationally. Structural measures are adopted both on the tool and also on the fastening device in that case in order to keep down the axial spacing, which is necessary for establishing a positively locking relationship between the fastening device and the tool, between the support ( 390 ) for the tool and the at least one projection ( 410 ) of the fastening device and/or in order to produce, during operation, in particular upon the occurrence of external forces such as braking or tilting forces acting on the tool, an additional force which holds the tool down On the support, whereby the positively locking relationship can be maintained and stabilised.

Description

The invention relates to a fastening device for a machine tool, with which a tool can be attached to the machine tool and an associated tool.

The tool may in particular be a separating, pushing, diamond, brushing, polishing or flap grinding wheel.

The use of such tools can be substantially simplified by providing a tool-free quick-release system with which the tool can be attached to the machine tool.

In the German Offenlegungsschrift DE 100 174581 a grinding machine tool holder is described with a driving device, via which a tool with a drive shaft is operatively connected. In this case, the insert tool via at least one movable against a spring element latching element with the driving device is connected, wherein the locking element engages in an operating position of the insert tool and fixes the insert tool form-fitting for use.

In the international publication WO 01/98029 is a fastening device according to the preamble of claims 1, 3 and 12, disclosed, which is mountable on a machine tool, wherein the fastening means projections a tool-operated shutter, which engage in a closed position on the closure surfaces of the tool, whereby the tool body is axially secured and rotatably supported. The projections of the fastening device and a support for the tool are arranged axially displaceable relative to each other, wherein the axial displacement is blocked by a centrifugal force, whereby a positive connection is fixed in the closed position between the fastening device and the associated tool for use.

The French patent FR 2063429 relates to a fastening device for a machine tool, in which drivers have drive surfaces which abut against corresponding surfaces of the tool. In the closed position fastening device and tool are not secured axially to each other. The American patent US 4,787,147 relates to a quick change mechanism for circular saws to attach or remove the saw blade without tools. In the closed position, a projection projects in each case over two radially displaceable blocking elements over the edge of the center opening of the saw blade, so that it is axially fixed.

The invention is based on the object when using such a quick-release system to increase safety to provide a small clearance between the tool and the fastening device in the closed position in the rest position and / or during operation.

This object is achieved on the device side by a fastening device with the features of claim 1 or 3 and a tool having the features of claim 12.

In this case, the fastening device for a machine tool comprises at least one, in particular radially outwardly facing, projection of a tool-actuated closure with which the fastening device with the tool is detachably connectable, engages in the closed position of the projection of the fastening device via an associated, in particular radially inwardly facing closure surface of the tool and the tool body secured axially and rotatably supported. A means for transmitting the drive torque from the machine tool to the tool is provided with a drive surface which extends inclined to the axis of rotation, wherein the tool rests in its operating position on the drive surface. With the specified structural design of the fastening device, an axially acting force can be generated on the tool when the tool, for example, due to external forces during operation, lifts from the support on the fastening device, so that the tool is pressed in operation on the support of the fastening device ,

In a further solution, the fastening device comprises a centrifugal force device which blocks or blocks the axial displaceability of the at least one projection and the support on the fastening device for the tool. In this case, the centrifugal device at least one centrifugally urged by a force means centrifugal force element and a means that the force on the at least one centrifugal element converts to produce an axially directed force for clamping the tool in the fastening device. Again, the specified structural design of the fastening device according to the invention is achieved that during operation of the fastening device in addition to a force acting in the rest position force acting in the axial direction operating force is generated, which presses the tool on the support of the fastening device. The fastening device according to the invention is constructed so that the at least one centrifugal force element has a substantially identical position in the radial direction both when the machine tool is stationary and when the machine is rotating. This means that a positive connection between the tool and the fastening device can be provided by axially acting force means when the machine is at a standstill, this positive locking being secured and / or stabilized during operation by the action of the centrifugal force device. Thus, a continuous and uniform, axially directed force during operation of the tool can be provided, since the force reversal can be carried out by the centrifugal force on the axially directed force for clamping the tool substantially motionless. The centrifugal force element can not build up high kinetic energy, which accordingly does not have to be dissipated. Further, since the centrifugal member is biased in the same direction in which the centrifugal force acts, a continuous power transfer is ensured by a Betriebsruhelage to a working operation.

The invention is further achieved by any tool that is designed to cooperate with one of the fastening device according to the invention. For this purpose, this comprises a circular disk-shaped tool body, which has a central opening for attachment to a machine tool and at least one, in particular radially inwardly facing closure surface of a tool-operated shutter, with which the tool with the fastening device can be brought into a form-fitting and the tool body axially secured and rotatably held.

The tool according to the invention, in conjunction with the associated fastening device, can have a cam control which is such that when the tool is rotated relative to the fastening device to establish a locking position between the tool and the fastening device, a cam can be guided over a surface which forms a control surface with at least two ramps is, wherein at least one projection of the fastening device is axially increased to a support of the tool on the fastening device against a mechanical force means and lowered again. As those skilled in the art will appreciate, according to the invention, the cam of the cam control can be arranged either on the tool or on the fastening device. Accordingly, depending on the embodiment, the control surface is located either on the tool or on the fastening device.

The tool according to the invention may in particular be a separating, pushing, diamond, brushing, polishing or flap grinding wheel.

In this case, a tool according to the invention may be distinguished by the fact that the at least closure surface is partially surrounded by a part extending segment is provided, which further comprises means for axially guiding a cam during the clamping operation on the at least one projection on the fastening means. The inventive design of the tool can be achieved that the axial displacement between the support and the at least one projection on the fastening device can be kept as low as possible, since the projection on the fastening device during the clamping operation is automatically controlled axially to support the tool to bring the tool and fastening device in an operating position, that is, in a positive connection. Furthermore, with the specified design of the tool, a pure rotational movement during the clamping process for the tool with a torque reduction can be converted into an axial displacement of the support to the at least one projection on the fastening device. Thus, a manual clamping of the tool is also possible against large axial biases, for example against axially acting springs with high spring constant.

The invention is based on the idea to make a quick clamping of a tool on a machine tool particularly safe by the necessary for the setting of a positive connection between the fastening device and the tool axial distance between the support for the tool and the at least one radial projection of the fastening device low is maintained and / or it is ensured that during operation, in particular when external forces such as braking or tilting forces on the tool an additional force is generated, which holds down the tool on the support, whereby the described positive engagement maintained and stabilized can.

According to the invention, the term "radially outward-pointing projection" comprises a section or a region of the fastening device which, when the closure is closed, that is, in the closed position, engages over a portion or region of the tool which provides said closure surface. Preferably, a plurality of radially outwardly facing projections on the fastening device are provided for the closure, each of which overlaps an associated, radially inwardly-facing closure surface of the tool, so that a substantially rotationally symmetrical axial fixation of the tool can be achieved. To avoid an imbalance, the components providing the form-fitting connection should preferably be arranged symmetrically on the tool and on the fastening device.

Advantageous embodiments are specified in the subclaims.

In the first solution of a fastening device according to the invention, a symmetrical application of the driving force to the tool and thus a symmetrical generation of an axially directed force on the tool can be provided by providing a plurality of drivers for transmitting the driving force to the tool. For example, drivers can be circumferentially spaced, in particular on an annular flange, which is rigidly connected to the support to be placed, each driver with its obliquely oriented to the axis drive surface bears against an associated drive surface of the tool. The direct connection of support and driver has the advantage that the driver press the tool directly on the support, without a power transmission via other components is necessary. In order to achieve an optimal pressure distribution and a stable position, each of the driver is with its drive surface on its associated drive surface of the tool on a form-fitting. The configuration of the dogs may take any convenient form to provide the drive torque transmission. It may be sufficient if the driver extends a few millimeters relative to the height of the support of the tool, wherein the drive surface preferably extends radially.

Suitably, the at least one centrifugal force element may have a radially outwardly extending conical or wedge surface, which in non-rotating machine tool, that is, in a rest mode position by a radially acting force such as a correspondingly arranged spring in contact with an associated cone or wedge surface of an axially movable Segments brought, which is in operative connection with the at least one projection of the fastening device. By this constructive measure, the reversal of the force which can be realized in the desired axial direction on the centrifugal force element in the radial direction both at rest centrifugal force element and rotating centrifugal force for clamping the tool. It is advantageous if the at least one projection of the fastening device is rigidly connected to the segment, which bears against the associated surface of the centrifugal force element. A particularly material-wear-free transmission can be achieved if the centrifugal force element has a radially outer conical surface, in particular at an angle of 45 ° to the axis, which rests against an associated conical surface of the axially movable segment, so that both surfaces substantially over their entire extent touch. The use of conical surfaces for force deflection is presently advantageous because the components are constructed rotationally symmetrical and thus a large surface area can be provided with conical surfaces.

To design the force reversal, it is particularly useful if the centrifugal force element is immovably positively guided in the axial direction and the associated cone segment is immovably positively guided in the direction perpendicular to the axis of the fastening device. Accordingly, the centrifugal element can only move in the radial direction and the cone segment only in the axial direction, so that a movement coupling is designed such that when no centrifugal force on the centrifugal force and a relative axial movement of the at least one projection away from the support of the tool, the centrifugal element moves radially inwardly, said movement counteracting a force means such as a spring described above.

For the design of a fastening device with a particularly low overall height can be provided that this comprises a base member having the support for the tool and a axially insertable into the base member and relative to this axially displaceable ring member on its outer shell a plurality of circumferentially spaced, radially outward pointing projections are arranged, which, as described above, engage over their closure surfaces in a closed position for forming a positive connection with the tool. In order to transmit a radial force to the ring element, a plurality of circumferentially spaced cone segments, each having a radially extending contact surface may be formed on the inner surface of the ring element, which cooperates with one of the described radially outer surface of a centrifugal force element.

In the first solution according to the invention for the fastening device can be provided that a plurality of circumferentially spaced flange segments are formed on the inner surface of the ring element, in which axially acting force means such as springs are supported for clamping the tool in the fastening device. It can thus be achieved that, even when the fastening device is stationary, a holding or clamping force is provided for maintaining the positive connection between the tool and the fastening device, for example when the machine tool is transported with the tool clamped on.

In order to provide an anti-rotation of the ring member in the base member, it may be provided that in the gap on the ring member, which is formed by two circumferentially adjacent cone, wedge or Flanschsegmente, in one with the base member rigidly connected, circumferentially extended and extending in the axial direction web engages positively. This web thus forms a positive guidance of the ring element in the base element. The ring element is therefore carried along by the base element during a rotation and is axially displaceable in this against the spring force and / or centrifugal force. Due to the usual, high centrifugal forces, angle grinders are operated at 13,000 revolutions / min, however, an axial displacement of the centrifugal element inward and thus a release of the positive connection between the tool and fastening device can be reliably prevented.

In order to seal the ring element relative to the base element, it can be provided that the ring element has a circumferential groove for receiving a seal against the base element. In order to prevent the ring element from hitting the base of the base element when the tool is not clamped, it can be provided that the ring element is supported on the drivers on the base element.

If the drivers are directly attached or molded onto the base element, the base element must therefore be rigidly connected to the machine tool in order to transmit the drive torque of the machine to the drivers.

As stated above, the fastening device according to the invention is designed so that the necessary for adjusting the positive connection between the tool and fastening device axial displacement between the support of the fastening device can be scanned by the radially outwardly facing projection. For this purpose, this has a radially expanded and extending towards the machine tool cam of a cam control with a front and a rear contact surface.

For sealing the cam portion at the outwardly facing Projection of the fastening device can be provided that extends from the cam in the direction of rotation a horizontally extending web on an associated driver. In this way, the projection can be supported on non-tensioned tool on the driver.

The construction described is particularly advantageous because the axial displaceability of the projection to the support, that is, here the ring element to the base element thickness variations of the tool can be compensated so that there is still a positive connection between the fastening device and the tool is provided by the Applying the axial force is secured to clamp the tool during operation of the machine.

A highly advantageous attachment means can be provided by combining the two indicated solutions, i. Has both at least one inclined to the axis driver, as well as the specified centrifugal force.

In a further embodiment of the tool according to the invention, which can be brought with the fastening device according to the invention in a closed position, the means for axially guiding the cam during the clamping operation has an obliquely formed and away from the machine tool first ramp and in the direction of rotation behind the first ramp in the plane perpendicular to the axis obliquely formed and the machine tool extending towards the second ramp. The thus designed control surface ensures that during the clamping process, which takes place in the form of a pure rotation of the tool to the fastening device, the axial distance between the support surface and the projection is first increased and then lowered again. On the specific design of the first ramp, which serves as Auflauframpe, on the one hand, the axial increase of the projection on the fastening device through the axial extent of the ramp exactly predetermined and further set by the circumferential extent of the manually applied against the axially acting force torque. Accordingly, a torque reduction can be provided, which makes it possible to use very strong axially acting force means in the fastening device, which also without the support of the operating forces described in the axial direction to hold the tool in positive engagement with the fastening device. It is understood that the described advantageous torque reduction can also be provided when the control surface as stated above is arranged on the fastening device and thus the cam to be guided on the tool.

It is particularly advantageous if the first ramp of the control surface is at the same time designed as a drive surface cooperating with a driver, via which the engine torque can be transmitted to the tool.

For the special design of the control surface on the tool a variety of designs are conceivable, in particular more than two ramps can be provided. It when at least one of the ramps is designed so that these braking forces can be transmitted from the tool to the projection of the fastening device, in particular the cam of the fastening device is particularly advantageous.

It has proven to be expedient to form the first ramp at an angle between 25 ° and 45 °, preferably 30 ° in a plane perpendicular to the axis, wherein the second ramp advantageously has an angle of ≤ 30 °.

It is advantageous if the segment on the tool in the direction of rotation at its peripheral end over the radial width has a web which provides a cover of the positive connection and extends axially to the end face, the Turned away machine tool. The front boundary surface of the web in the direction of rotation may be suitably designed so that an air flow is generated, which allows blowing off the abrasive particles from the quick-release system during its operation. On the other hand, this web can be used to provide connection means for a cover, which can be connected to the tool facing away from the machine tool with the tool, whereby a particularly advantageous dust protection can be provided.

The at least one segment on the tool, which provides the at least one closure surface of the tool, can be formed either directly on the tool body or on a carrying device which is provided in an opening of the tool body and fixed thereto. The support means may be made of plastic and is securely attachable to a tool body via an adhesive method. The support device can also be made of metal and be pressed for example in the manufacture of the tool body.

The advantageous method according to the invention for tool-free clamping of a tool is characterized in that after the axial merging of the tool and fastening device in a conventional manner, the axial distance between the support surface and the projection on the fastening device is not increased by an axial direction in the axial direction Force must be applied to the support by pressing on the tool. Instead, an axial displacement is generated by a pure rotational movement by means of a force deflection in order to increase the axial distance between said components, so that a positive connection between the tool and the fastening device can be adjusted. Upon reaching the closure position is lowered by a corresponding axial control of at least one cam, the axial distance between the support and the projection on the fastening device again, which ultimately the Device with the fastening device in an unsecured positive locking device, which is secured in operation by the described acting on the tool operating forces.

Advantageously, during rotation for producing a closure position via a cam control between the tool and the fastening device, the cam is guided via a control surface with at least two ramps, wherein at least one projection of the fastening device axially increases to support the tool on the fastening device against a mechanical force means and lowered again becomes.

Advantageously, the guiding of the cam over the control surface is continuous during the entire tightening process, so that the cam control is also used for the clamping operation, i. the release of the tool from the fastening device, can be used. For this purpose, a relative rotation of the tool to the fastening device is to be generated in a simple manner, which is the opposite direction during clamping.

Because of the possible different arrangement of the parts of the cam control according to the invention on the fastening device or the tool in a first embodiment when turning a cam on the fastening device via a control surface on the tool are performed and in another embodiment, a cam on the tool via a control surface the fastening device. In the first case, the cam may be mounted on a projection on the fastening device, wherein the control surface is arranged on the closure surface of the tool. In the described second case, the control surface can be arranged on the projection of the fastening device, while the cam is arranged on the closure surface of the tool.

Fig. 1

in einer Explosionsdarstellung eine erste erfindungsgemäße Befestigungseinrichtung zusammen mit dem zugeordnet ausgebildeten Werkzeug,

Fig. 2

die in Fig. 1 dargestellte Befestigungseinrichtung in einer Aufsicht,

Fig. 3

eine Schnittdarstellung entlang der Linie A-A der in Fig. 2 dargestellten Befestigungseinrichtung,

Fig. 4

eine Schnittdarstellung entlang der Linie B-B der in Fig. 2 dargestellten Befestigungseinrichtung,

Fig. 5

eine Schnittdarstellung entlang der Linie C-C der in Fig. 2 dargestellten Befestigungseinrichtung,

Fig. 6a

ein Basiselement der erfindungsgemäßen Befestigungseinrichtung in einer perspektivischen Ansicht,

Fig. 6b

das Basiselement in einer Ansicht von unten,

Fig. 6c

das Detail eines Mitnehmersteges am Basiselement,

Fig. 7a

ein Ringelement der erfindungsgemäßen Befestigungseinrichtung,

Fig. 7b

das Ringelement in einer Ansicht von unten,

Fig. 7c

in einer vergrößerten Ansicht den Aufbau eines teilumfänglich verlaufenden Vorsprungs am Ringelement,

Fig. 8a

den Deckel einer erfindungsgemäßen Befestigungseinrichtung in einer Aufsicht,

Fig. 8b

den Deckel in einer Schnittdarstellung,

Fig. 8c

den Deckel in einer Ansicht von unten,

Fig. 8d

den Deckel in einer perspektivischen Ansicht,

Fig. 9a

eine auf ein erfindungsgemäßes Werkzeug von oben aufsteckbare Schutzhaube in einer Aufsicht,

Fig. 9b

die Schutzhaube in einer Schnittdarstellung und

Fig. 9c

die Schutzhaube in einer Unteransicht,

Fig. 10a

eine Trageinrichtung eines erfindungsgemäß gestalteten Werkzeugs in einer Aufsichtdarstellung,

Fig. 10b

die Trageinrichtung in einer Schnittdarstellung entlang der Linie A-A,

Fig. 10c

die Trageinrichtung in einer Schnittdarstellung entlang der Linie B-B,

Fig. 11

in einer Explosionsdarstellung eine zweite Ausführungsform einer erfindungsgemäßen Befestigungseinrichtung mit zugehörigem Werkzeug,

Fig. 12

die in Fig. 11 dargestellte Befestigungseinrichtung im Zusammenbau in einer Aufsicht, und

Fig. 13

die in Fig. 12 dargestellte Befestigungseinrichtung in einer Schnittdarstellung entlang der Linie A-A zeigt.

The invention will now be described by describing several embodiments with reference to the accompanying drawings explains

Fig. 1

in an exploded view, a first fastening device according to the invention together with the associated trained tool,

Fig. 2

in the Fig. 1 shown fastening device in a plan view,

Fig. 3

a sectional view taken along the line AA in Fig. 2 illustrated fastening device,

Fig. 4

a sectional view taken along the line BB of in Fig. 2 illustrated fastening device,

Fig. 5

a sectional view taken along the line CC in Fig. 2 illustrated fastening device,

Fig. 6a

a base element of the fastening device according to the invention in a perspective view,

Fig. 6b

the base element in a view from below,

Fig. 6c

the detail of a carrier web on the base element,

Fig. 7a

a ring element of the fastening device according to the invention,

Fig. 7b

the ring element in a view from below,

Fig. 7c

in an enlarged view the structure of a partially circumferential projection on the ring element,

Fig. 8a

the lid of a fastening device according to the invention in a plan view,

Fig. 8b

the lid in a sectional view,

Fig. 8c

the lid in a view from below,

Fig. 8d

the lid in a perspective view,

Fig. 9a

a protective hood which can be attached to a tool according to the invention from above, in a plan view,

Fig. 9b

the guard in a sectional view and

Fig. 9c

the protective cover in a lower view,

Fig. 10a

a supporting device of a tool designed according to the invention in a plan view,

Fig. 10b

the support device in a sectional view along the line AA,

Fig. 10c

the support device in a sectional view along the line BB,

Fig. 11

in an exploded view, a second embodiment of a fastening device according to the invention with associated tool,

Fig. 12

in the Fig. 11 shown fastening device in the assembly in a plan view, and

Fig. 13

in the Fig. 12 shown fastening device in a sectional view along the line AA shows.

Fig. 1 is an exploded view of a first embodiment of the fastening device according to the invention, which is shown together with the tool 2 to be clamped. The fastening device comprises as essential components a base element 3, a ring element 4, four centrifugal force elements 5, of which in each case two springs 6 are supported, and a cover 7, which can be screwed to the base element 3. For this purpose, screws 8 extend through the cover into threaded bores 310 on the base element.

This can be attached via the nut 10 to the spindle of a machine tool, not shown. For this purpose, the spindle of the machine tool extends through a central opening 320 to beyond the cover 7, wherein this has at its central opening a circumferential countersink 710, in which the mother with a directed to the machine tool circumferential cone for centering the entire device on the machine tool intervenes.

The base member 3 has at an angle of 90 ° circumferentially spaced four cylinder segment webs 330, which taper radially inwardly and merge into a socket portion 340 of the base member. The cylinder segment webs 330 and bushing 340 extend down to the bottom 350 of the base member 3. On a flange 360, which is axially raised relative to the ground, there are four dog lands 370 spaced circumferentially at 90 °. The webs extend in the axial direction depending on the embodiment by a few millimeters, in this case by 5 millimeters. In the direction of rotation S, the carrier webs have a drive surface 372 arranged at an angle to the axis, via which the drive torque of the machine is transmitted to the tool 2. The drive surfaces are arranged radially for optimum transmission of force, that is, they are parallel to a radius of the device. Between the cylinder segment webs 330 and the axial extent of the flange 360 down to the machine tool, a circumferential gap is formed into which the ring element 4 can be inserted.

The ring element has on the inner shell at the base element 3 directed end four cone segments 420, wherein in each case between two adjacent cone segments a circumferential gap is formed, in which engage with the base member 3 whose Zylindersegmentstege 330 engage, so that the ring member is rotatably connected to the base member and thus carried by this. The ring element has one degree of freedom in the base element, ie in the axial direction. To seal the base member against the axially movable ring member has the latter in the axial height of the cone segments on a circumferential groove 430, in which an x-seal, not shown, is introduced. To provide the axial displaceability of the ring element in the base member, the axial extent of the cylinder segment webs 330 is greater than the axial extent of the cone segments 420, which are formed flush with the bottom of the cylinder segment 4. The axial displaceability of the ring element, which is necessary for adjusting the closure position between the tool and the fastening device, can be made very small in the design according to the invention, and for example be two to four millimeters. On the base element opposite end face of the ring member four projections 410 are arranged on the outer shell, which extend radially outwardly and are structured towards the tool 2, with the closure segments 210 of the tool 2 in a manner to be described for setting an unsecured positive connection between the Tool 2 and the fastening device 1 cooperate.

How out Fig. 1 shows, in each case to a cone segment 420, a centrifugal element 5 is provided which rests with a cone of the cone associated cone surface which extends radially outwardly thereto. The centrifugal force element lies with its lower boundary surface 520 on the base 350 of the base element and with its upper boundary surface 520 on the underside of the lid 7. In this way it is ensured that the centrifugal elements 5, regardless of the position of the ring element 4 can not move axially substantially, but only radially. On the axis facing and arranged parallel to this side surface 540, the centrifugal elements each have two blind holes, in which a spring 6 is inserted, which extends out of the blind hole outwards. The dimension of the spring is such that it is supported in each operating position by a flat side surface 380 of the socket part of the base element 3. As a result of the design described, it is achieved that the centrifugal force elements 5 are motion-coupled to the ring element 4 in each operating position and, furthermore, a means for force deflection is provided. Since the centrifugal force elements rest under spring force on the cone segments 420 of the annular part, an axially directed force thus also acts in the rest position downwards in the direction of the base element. With non-rotating base element, the ring element 4 can be moved against the spring force of the springs 6 upwards away from the support 390 on the base element, on which the tool 2 rests. However, if the base member is driven, in addition to the spring forces, a centrifugal force acts on the centrifugal force elements 5, whereby the ring member and thus also the protrusions attached thereto are pressed with high force in the direction of the support 390.

Since the ring element 4 also moves relative to the cover 7, this has a circumferential groove 720, in which a not shown in the figure, sealing ring is introduced.

Fig. 2 shows the in Fig. 1 shown fastening device in the assembled state in a plan view in the event that a tool 2 is clamped in the fastening device. A protective hood 9, which has a horizontally extending flange and an axially extending lateral surface, is clipped onto the tool 2 in order to cover the radial section in the region of the projections 410 and the closure segments 210.

In another embodiment, the in Fig. 2 Protective hood 9 shown also integrally formed on the tool or the support means of the tool.

Fig. 3 shows the in Fig. 1 illustrated fastening device with clamped tool in a sectional view along the line AA, wherein a spindle 11 is shown, to which the fastening device is fastened via the nut 10. The tool 2 rests on the support 390 of the base part, wherein in the illustrated closure position, the axially inwardly facing closure segments 210 are overlapped by projections 410 pointing radially outward. As is also apparent from the drawing, the centrifugal force elements lie with their conical surfaces on the associated conical surfaces of the segments on the ring element, whereby the tool 2 is held down in the rest position with a spring force. The protective cover 9, which has already been described, first extends horizontally inwards starting from an upper flange of the tool and then extends axially downwardly with a sealing lip 910 supported on the cover 7.

Fig. 4 shows the in Fig. 2 shown fastening device with clamped tool in a sectional view taken along the line BB. Evident are the screws 8, which are screwed into the threaded bore 310 of the base part 3 and with which the lid 7 is fixed to the base member. The drawing shows the sealing of the ring element 4 with the seal 440 in the region of cylinder segment webs 330.

Fig. 5 shows a section along the line CC of Fig. 2 That is, in a radial region in which, with the tool clamped, a positive engagement between the outwardly facing projections 410 of the fastener and the radially inwardly facing closure surface 220 of the tool provided by a closure segment 210 is adjusted. In the specified positive fit is also each case a Mitnehmersteg 370 of the base member to a drive surface 230 of the closure segment for transmitting the drive torque to the tool. The projection 410 has a braking surface 411, which bears against a correspondingly shaped surface of the tool and absorbs the braking forces occurring on the tool.

In Fig. 6 the base element 3 is shown in an already shown perspective view (a) and in a bottom view (b), wherein in FIG. 6 in detail in a side view of the structure of a Mitnehmersteges 370 is shown. According to Fig. 6 b ) is formed on the underside of the bottom 350 of the base member 3, a central recess 355 in the form of a rectangle, in which engages a correspondingly shaped driver of the spindle of the machine tool, see, for example Fig. 4 , Out Fig. 6c) is the design of a Mitnehmersteges 370 shown with its associated drive surface 372, which bears flat against the drive surface 230 of the tool. In the illustrated example, the angle of the drive surfaces to the axis is 45 °.

In Fig. 7 the ring element 4 is again shown in a perspective view (a) and further in a view from the bottom (b), wherein in Fig. 7c) in a side sectional view of the structure of an outwardly radially extending projection is shown as part of the tool-less closure. As can be seen, the cone segments 420 extend to the end face of the ring element 4. The design according to the invention on the underside, that is to say in the direction of the tool of the circumferentially extending projections 410, is shown in FIGS Fig. 7b) and c) out. The projections have on the side facing the tool in each case a cam 411, which is designed for the clamping operation for driving over an associated designed closure surface of the tool. Starting from the cam opposite to the direction of rotation of this a horizontal web 413 is arranged, with which the projection is supported at an associated Mitnehmersteg 370 with non-clamped tool, see Fig. 5 , In the Fig. 7 illustrated braking surface 411 for transmitting a braking torque from the tool to the ring member has present at an angle of 30 °.

In Fig. 8 a) to d) the cover 7 of the fastening device according to the invention is shown in different perspectives. As seen from the bottom ( Fig. 8c) shows, the lid is designed substantially flat on its underside, so that the centrifugal elements 5 abut it and as described, are constrained in the radial direction.

In Fig. 9 Different views of the dirt hood 9 are shown. This has on its underside circumferentially equidistant spaced and axially extending pins 920, which are inserted into suitably arranged holes 260 on the closure segments 210 of the tool, see Fig. 1 , Advantageously, the lid 9 may be formed of a transparent plastic which is elastic, so that the sealing lip 910 may be integrally formed on the lid. In the in Fig. 9 In the illustrated embodiment, the lid is made of a transparent material and further formed circumferentially adjacent to the pins each have a convex projection 930, which has the function of a lens. These lenses, due to their attachment to the closure segments of the tool, are arranged to allow a view of the abutment of the respective projection 411 against the associated closure segment 210, thereby providing optical control of the closure position between the tool and the fastening device.

As described, the closure segments designed according to the invention with the closure surface, which cooperates with the projection on the fastening device for providing a positive connection, can be designed directly on the tool body or on a support device which supports the tool body wearing.

Fig. 10 shows an example of such a support device, similar to those in Fig. 1 is shown constructed. It shows Fig. 10 a) a supervision and the Fig. 10b) or c) a sectional view along the line AA or BB. For axial guidance of the cams 412 of the ring element, see Fig. 7 , During the clamping process and to provide a positive connection between the projections of the fastening device and the closure surface, the tool 2 each have a closure segment 210 which is provided in the direction of the projection 410 of the ring member with a structured closure surface 220. This closure surface 220 includes a first ramp 230, which is also formed as a drive surface for engagement with a driver land 370 and therefore has an angle to the horizontal of 45 ° and is designed to rise axially. After reaching an axial maximum, the surface drops axially again in a second ramp 240. This ramp has in the described embodiment to the horizontal at an angle of 30 ° and serves as abutment of the braking surface 411 of the cam 412, see Fig. 5 , The angle of the second ramp is kept lower compared to the first ramp, so that a worn tool can still be easily clamped by the fastening device. It should be noted that a worn tool usually has a smaller diameter, so that with the same force compared to clamping, when clamping a lower torque can be developed by the user. This disadvantage is compensated by the lower slope of the second ramp.

Fig. 11 shows an embodiment of the fastening device of the invention, which does not require a centrifugal force, that is, the operating force for holding down the tool alone by the inclined contact of the driver 370 on the drive surface 230 of the closure segment 210 of the tool reached. A positive connection according to the understanding of the invention is realized as in the first embodiment only during operation, that is, during rotation of the fastening device. Only by the occurrence of an additional axial force, either caused by the Mitnehmerstege or by the fly-power device and the Mitnehmerstege the tool can be securely held on the support. For holding the tool in the closed position in a rest position of the fastening means a plurality of springs 13 are provided, which are supported on the lid 7 and press on horizontal segments 450 which extend radially inwardly and circumferentially on the interior of the ring member 4. Since the further construction of in Fig. 11 shown fastening device substantially identical to that of in Fig. 1 is shown, may be made in view of the further structure and operation of the first embodiment.

FIGS. 12 and 13 show a plan view and a sectional view of the in Fig. 11 shown fastening device, wherein concerning Fig. 13 reference is made to the well-visible on average springs 13, which rest on the horizontal segments 450 and thus hold down the ring member, whereby the tool 2 is held on its support 390.

An inventively designed tool can be brought by the fastening device according to the invention thereby in a closed position by the tool is brought with its closure segments in the circumferential gaps between the projections of the fastening device, here the ring member and placed on the support 390. Now, the tool and the fastening device are moved relative to each other, for example, the tool against the direction of rotation of the machine tool while holding the fastening device. It should be noted that no direct axial force has to be applied by the user during the clamping process. As the rotational movement progresses, the cam of the Fastening device against the first ramp on the tool, which has the result of further rotation that the cam of the projection on the first ramp of the tool is moved upward, whereby the ring member moves axially in the same way. After reaching the axially highest point of the closure surface of the tool, the cam on the second ramp due to the axially acting spring force runs down, whereby the cam comes to lie in a radially inwardly open pocket, which through the second ramp and the web the closure segment is formed, see Fig. 5 , This position of the cams relative to the closure segments in the closure position corresponds to a form fit, which is ensured by the occurrence of the axially directed operating forces as described.

LIST OF REFERENCE NUMBERS

1

fastening device

2

Tool, carrying device for tool body

3

base element

4

ring element

5

centrifugal force element

6

feather

7

cover

8th

screw

9

guard

10

mother

11

spindle

12

support means

13

feather

210

closure segment

220

closure surface

230

Driving surface, 1st ramp

240

Braking surface, 2nd ramp

250

web

260

admission

310

Threaded hole.

320

opening

330

Cylinder segment Steg

340

female connector

350

ground

355

recess

360

flange

370

driving web

372

drive surface

380

flat side surface

390

edition

410

head Start

411

brake surface

412

cam

413

Horizontal jetty

420

cone segment

430

groove

440

poetry

450

Horizontal segment, flange segment

510

conical surface

520

Upper interface

530

Lower interface

540

side surface

710

lowering

720

groove

730

poetry

910

sealing lip

920

pen

930

survey

1110

Ring cone of the mother

Claims (26)

1. A fastening device (1) for a machine tool for co-operation with a tool (2) having a tool body in the form of a circular disc with a central opening, comprising a means for transmission of a drive torque to the tool (2) and at least one projection (410) of a closure means which can be actuated without a tool and with which the fastening device (1) can be releasably connected to the tool (2), wherein in the closure position the at least one projection (410) of the fastening device (1) engages over an associated closure surface (220) of the tool (2) and the tool body is axially secured and held fixed against rotation and the at least one projection (410) and a support (390) for the tool are arranged on the fastening device (1) for the tool (2) for axial displacement relative to each other,
   characterized in that the means (220, 230) for transmitting a drive torque includes at least one entrainment member (370) with a drive surface (372) which extends in an inclined fashion relative to the axis of rotation, the tool (2) resting against the drive surface (372).
2. A fastening device according to claim 1,
   characterized by several entrainment members which are rigidly connected to the support and which are arranged circumferentially spaced from each other, wherein each entrainment member (370) rests with its drive surface (372) in a positively locking relationship against an associated drive surface (230) of the tool (2).
3. A fastening device (1) for a machine tool for co-operation with a tool (2) having a tool body in the form of a circular disc with a central opening, comprising a means (220, 230) for transmission of a drive torque to the tool (2) and at least one projection (410) of a closure means which can be actuated without a tool and with which the fastening device (1) can be releasably connected to the tool (2), wherein in the closure position the at least one projection (410) of the fastening device (1) engages over an associated closure surface (220) of the tool (2) and the tool body is axially secured and held against rotation and the at least one projection (410) and a support (390) are arranged on the fastening device (1) for the tool (2) for axial displacement relative to each other, wherein the axial displacement path can be blocked by a centrifugal force device,
   characterized in that the centrifugal force device has at least one centrifugal force element (5) which is urged radially outwardly by a force means (6), and a means (4) which converts the force on the at least one centrifugal force element (5) for producing an axially directed force for clamping the tool (2) in the fastening device (1), wherein the at least one centrifugal force element (5) assumes a substantially identical radial position both in a rest operative position and also upon the action of a centrifugal force.
4. A fastening device according to claim 3,
   characterized in that the at least one centrifugal force element (5) has a radially outward wedge or conical surface (510) which extends in particular at an angle of 45 degrees relative to the axis and which in a rest operative position is moved by the force means (6) into a position of resting against an associated wedge or cone surface of axially movable wedge or cone segment (420) which is operatively connected to the at least one projection (2) of the fastening device.
5. A fastening device according to claim 4,
   characterized in that the centrifugal force element (5) is guided to be immobile in the axial direction and that the associated wedge or cone segment (420) is forcibly guided in a direction perpendicular to the axis.
6. A fastening device according to one of the claims 1 to 5,
   characterized by a base element (3) which comprises the support (390) of the tool (2) and an annular element which can be axially introduced into the base portion and which is axially displaceable relative thereto and at the outer periphery of which are arranged several peripherally spaced, radially outwardly facing projections.
7. A fastening device according to claim 3 and 6,
   characterized in that at the inner periphery of the annular element (4) several radially inwardly extending, circumferentially spaced wedge or cone segments (420) are formed, each of which having a respective radially inwardly directed contact surface.
8. A fastening device according to claim 1 and 6,
   characterized in that at the inner periphery of the annular element (4) several radially inwardly extending, circumferentially spaced flange segments (450) are formed at which axially operative force means (13) are supported for clamping the tool between the support (390) and the at least one projection (410) in the fastening device.
9. A fastening device according to claim 6, 7 or 8,
   characterized in that on the annular element (3) a circumferential gap is provided by and between two circumferentially neighbored wedge, cone or flange segments (420, 450), which gap positively engages around a leg (330) which is rigidly connected to the base element and which is circumferentially extensive and extends in the axial direction, to provide a non-rotatable mounting of the annular element (4) in relation to the base element (3) and displaceability of the annular element in the axial direction.
10. A fastening device according to one of the claims 1 to 9,
    characterized in that a radially outwardly facing projection (410) of the fastening device includes a cam (412) extending towards the machine tool and in the direction of rotation a front and a rear supporting surface.
11. A fastening device according to claim 10,
    characterized in that a horizontal and circumferentially extending leg (413) extends from the cam (412) to an associated entrainment member (370) on which the projection (410) rests when the tool is not in a clamped condition.
12. A tool (2) comprising a tool body in the form of a circular disc which has a central opening for fastening to a machine tool, with at least one closure surface (220) of a closure means which can be actuated without a tool, with which the tool (2) can be releasably connected to a fastening device (1), in particular to a fastening device according to one of the claims 1 to 11, wherein at least one projection (410) and one support (390) are arranged on the fastening device for the tool (2) for axial displacement relative to each other, and in the closure position the at least one projection (410) on the fastening device (1) engages over the at least one closure surface (220) of the tool and the tool body is axially secured and held against rotation, characterized in that the at least one closure surface (220) is provided by a circumferentially extending segment (210) which also includes a means (230, 240) for axially guiding a cam (412) of the at least one projection (410) of the fastening device (1) during the clamping operation, wherein during the clamping operation the means (230, 240) transmits a force to the cam (412), for changing the axial spacing between the at least one projection (410) and the support (390) on the fastening device (1).
13. A tool according to claim 12, characterized in that the means for axially guiding the cam of the fastening device during the clamping operation includes, in the direction of rotation, a first ramp (230) which is configured to be inclined relative to the axis and behind the first ramp a second ramp (240) which is configured to be inclined relative to the axis.
14. A tool according to claim 12 or 13, characterized in that the first ramp (230) is additionally configured as a drive surface against which after the clamping operation an associated entrainment member (370) of the fastening device rests with its drive surface (372) for transmission of the torque drive.
15. A tool according to one of the claims 13 to 14, characterized in that the first ramp (230) is at an angle of 25 to 45 degrees in a plane perpendicular to the axis.
16. A tool according to claim 15, characterized in that the first ramp (230) is at an angle of 30 degrees in a plane perpendicular to the axis and the second ramp (240) is at an angle of ≤ 30 degrees in a plane perpendicular to the axis.
17. A tool according to one of the claims 12 to 16, characterized in that the segment (210) on the end thereof opposite to the direction of rotation includes a leg (250) which extends axially to the front side directed away from the machine tool.
18. A tool according to one of the claims 12 to17, characterized in that segments which provide closure surfaces are formed on a carrier device which is provided in an opening of the tool body and is fixed thereto.
19. A method for tool-free clamping a tool (2) according to one of the claims 12 to 18 on a fastening device (1) for a machine tool, in particular on a fastening device (1) according to one of the claims 1 to 11, wherein the tool (2) and the fastening device (1) are axially aligned in an opening position of the closure means and brought together, and wherein a closure position is produced by a rotary movement, in which position at least one, in particular radially outwardly facing projection (410) of the fastening device(1) engages over an in particular inwardly radially inwardly facing closure surface (220) of the tool (2), so that the tool body is axially securely held and a positive connection is established between the fastening device (1) and the tool (2),
    characterized in that upon rotation of the tool (2) relative to the fastening device (1) a reversal of movement is effected, for changing the axial spacing of the at least one projection (410) of the fastening device relative to a support (390) of the tool (2), wherein the relative axial displacement is produced by a pure rotary movement by means of force deflection.
20. A method according to claim 19, characterized in that in the rotary movement intended for producing a closure position through a cam control between the tool and the fastening device a cam (412) is automatically guided over a surface (220) having at least two ramps (230, 240), wherein the at least one projection of the fastening device is raised axially with respect to the support against a mechanical force means and is lowered again.
21. A method according to claim 20, characterized in that guiding the cam (412) over the surface (220) acting as a control device is effected continuously through the entire clamping operation by the relative rotary movement between the tool and the fastening device.
22. A method according to claim 20 or 21, characterized in that during the rotary movement a cam (412) on the fastening device is guided over a control surface (220) on the tool (2).
23. A method according to claim 20 or 21, characterized in that during the rotary movement a cam on the tool is guided over a control surface on the fastening device.
24. A method according to claim 20, 21, 22 or 23, characterized in that with the lowering movement a positively locking engagement between the fastening device and the tool is achieved.
25. A method according to one of the claims 20 to 24, characterized in that during unclamping of the tool from the fastening device a rotary movement of the tool relative to the fastening device is produced manually which is oppositely directed with respect to that in the clamping operation, whereby the tool and the fastening device are disengaged by releasing the positively locking engagement through the force deflection by way of guiding the cam (412) over the control surface (220).
26. A method according to one of the claims 19 to 25, characterized in that during operation a force is produced which acts in the axial direction and which presses the tool against its support in the fastening device.

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