EP3131719B1 - Tool head and method for inserting and clamping a cutting insert, and cutting insert - Google Patents

Description

The invention relates to a tool head according to the preamble of claim 1 and a method for inserting and clamping a cutting insert according to the preamble of claim 5.

State of the art

Through the DE-OS 36 36 618 a knife shaft for cutting woodworking machines is known, in particular for planing machines. It has a one-piece shaft body, which has several axially parallel grooves narrowing towards the lateral surface, in each of which sits a profiled disposable knife braced by a centrifugal wedge, which positively engages in a corresponding profiling of the side surface of a retaining strip lying between disposable knife and centrifugal wedge. The retaining bar is immovably connected to the shaft body and elastically deformable. It is arranged at such a distance from the side wall of the groove that, when the centrifugal wedge is released, an intermediate knife can be easily pulled out in the longitudinal direction and a new knife can be inserted practically without play. When the centrifugal wedge generates the clamping force by rotation, the retaining strip is pressed firmly against the disposable knife by slight elastic deformation, so that it remains firmly in place. However, the knife can only be clamped in a single, unchangeable position.

The German utility model DE-U-8914 809 discloses a cutter head for machining wood, plastic and the like, in particular for longitudinal profiling of strips and plates, with a cylindrical base body which has a plurality of axially parallel grooves open to the lateral surface. A knife is clamped in each groove between a side wall of the groove and a retaining strip, a toothing of the knife back engaging in a form-fitting manner with a corresponding toothing of the side wall. The groove towards the outer surface of the base body is narrowed in a wedge shape. A centrifugal wedge is arranged in this, which firmly clamps the knife between the holding bar and the other side wall when the base body rotates.

U.S. Patent Application No. 2002/0046632 discloses a tool body with one or more tool holders, in which cutting edges can be used, which are held by a clamping mechanism. In order to keep the tool costs low, the US 2002/0046632 plan to re-sharpen the cutting edges and remove an equal amount from the cutting edge base, thus creating a new reference edge. The inserted cutting edges have a groove at a distance from the cutting edge base, into which a protruding rib formed in the tool holder engages when the cutting edge is clamped in the holder. The groove is provided on the flat side of the cutting edge opposite the cutting edge and prevents the cutting edge from slipping radially during operation. According to US 2002/0046632 the rib can alternatively be provided on the fastening wedge to achieve the same purpose.

U.S. Patent Application No. 2005/0265795 shows a tool head with a tool holder, in which a cutting edge can be clamped by means of a fastening wedge. The cutting edge has a chamfer on the cutting edge base and opposite the flat side with the cutting edge, which creates the necessary space when the cutting edge is inserted into the tool holder opening.

To replace or adjust the knife, the centrifugal wedge is first loosened by radially inward force, for example by a hammer blow. The retaining strip, which is slightly deformed in the tensioned state in the direction of the knife, returns in it; relaxed location back. In this position, which is precisely defined by the stop edge between the two strips, the seat of the knife is loosened to such an extent that it can be easily pulled out in the direction of the axis of the base body. Then, if necessary after grinding, the knife can be inserted again in the axial direction, for example in a position that is shifted outward by a tooth width. As soon as the cutter head is rotated rapidly, the centrifugal force tightens the centrifugal wedge. The knife is now firmly and precisely clamped. Since the centrifugal wedge is designed to be self-locking, it remains tensioned even after the cutter head has been stopped. An advantage of the knife head described is that the screws do not have to be loosened when changing the knife. The disadvantage, however, is that the knife is only in the axial direction can be pulled out of the groove. This means that neighboring cutter heads must first be removed from the tool spindle before the cutter can be removed.

Knife heads with conventional knife holders without centrifugal wedges usually require several screws when using wide knives to attach the knives to the knife head. This requires more work when changing knives. Another problem with such conventional cutter heads is that the pressure bodies are fastened with screws in a groove of the cutter head against the centrifugal force that arises during rotation. At high speeds, the centrifugal forces can cause the knife to shift slightly, which affects the accuracy of the woodworking and leads to greater tolerances.

Object of the invention

It is therefore an object of the present invention to provide a tool head, in particular a cutter head for a machine tool for woodworking, and a method in which the tool or. Knife can be inserted and removed in the radial direction. Another aim is to provide a tool head in which a prior disassembly of tool heads adjacent to the tool head is no longer necessary when changing tools or knives. Another goal is to propose a tool head that minimizes the work involved in changing tools. Another goal is that when a tool is changed, the new tool is precisely adjusted in the radial and preferably axial direction.

description

According to the invention, the aforementioned goals are achieved by the features of claims and 5. Advantageous further developments are defined in the subclaims.

The invention relates to a tool head, in particular a cutter head for a woodworking machine, with a cylindrical, conical or profiled base body for rotating machining of a workpiece. The tool head has at least two tool holders arranged uniformly distributed over its circumference for holding a cutting insert. The tool holders each have narrowing grooves in the radial direction, in each of which a cutting plate can be clamped between a first side wall of the groove and a closure element serving as a pressure jaw. A centrifugal wedge, which can be inserted into the groove, can press the locking element against the cutting plate and fix the latter in the tool holder. A first interlocking connection is provided between the cutting plate and the first side wall, which fixes the cutting plate in the radial direction.

According to the invention, a second positive connection is provided between the closure element and the centrifugal wedge. This arrangement of the interlocking connections, namely between the insert and the tool head on the one hand and the closure element and the centrifugal wedge on the other hand, has the advantage that a relative movement between the closure element and the insert is possible when clamping because there is no interlocking connection between the insert and the closure element. The proposed arrangement of the interlocking connections also allows the cutting insert to be inserted into the groove in the radial direction.

The centrifugal wedge advantageously has a bore with an internal thread into which a clamping screw with an external thread can be inserted. The centrifugal wedge can be moved into the clamping position by rotating the clamping screw in a first direction and into the tool changing position by rotating the clamping screw in a second, opposite direction. Compared to the prior art, this tool holder has the advantage that the centrifugal wedge is preloaded outwards in the radial direction when the tool is clamped. This has the advantage that the centrifugal wedge and the cutting plate no longer move when the tool head begins to rotate. According to an advantageous embodiment, the clamping screw is a threaded pin, on one end face of an attack means, for example a hexagon socket or a Torx screw driving profile, and on the second end face a preferably cylindrical screw head It is conceivable that the screw head has a latching extension on the end face, which can engage with play in a corresponding blind hole in the groove base. This has the advantage that the centrifugal wedge cannot move in the groove. Incidentally, the blind hole and the latching extension are designed in such a way that radial pre-assembly of the clamping screw is possible.

A screw hole with an internal thread is advantageously provided in the base of the groove, and the shaft of the clamping screw has two threaded sections with opposite screw threads. This has the advantage that, if the direction of rotation of the screw thread is selected appropriately, the centrifugal wedge moves away from the groove base when the clamping screw is screwed into the screw hole. According to another embodiment, the clamping screw can be inserted rotatably but immovably in the axial direction into the bore of the centrifugal wedge. In this way, too, the centrifugal wedge can be pressed against the closure element by turning the clamping screw.

The closure element is expediently accommodated in the tool holder without screws. fixed positively by the centrifugal wedge in the tool change position. This has the advantage that it can be inserted or removed quickly. This makes tool changing easier.

According to a preferred embodiment, either the closure element or the centrifugal wedge is equipped with at least one magnet. The provision of at least one magnet has the advantage that the cutting plate, which is advantageously made of a weakly magnetizable material, is held on the closure element. This has the advantage that the cutting insert is pulled towards the closure element in the tool change position. Because the insert is additionally tilted when the centrifugal wedge is released, it can be gripped easily with your fingers.

The at least one magnet is preferably inserted into a recess of the closure element flush with its surface. This has the advantage that the cutting plate can lie flat against the closure element. For reasons of symmetry, at least there are expediently in the closure element two spaced-apart recesses are provided, in which magnets are inserted flush.
The one or more cutouts in the lower region of the closure element are advantageously provided at a short distance from the base of the closure element, in particular in the lower third of the closure element. However, other positions are also possible depending on the dimensions of the insert.

According to a particularly advantageous embodiment, a pressure or spring element is provided which is positioned in the groove in such a way that when the cutting insert is clamped in, it acts on the cutting insert in the radial direction outward and presses it against a stop. The pressure element is advantageously elastically or resiliently deformable and, for example, made of an elastically deformable plastic or a spring element, for example a spiral spring. The pressure or spring element is preferably located where the lower edge of the cutting plate rests on a shoulder of the tool holder, so that the pressure or spring element can interact with the lower edge of the cutting plate. The pressure or spring element can be inserted into the groove or arranged on the closure element.

An expedient embodiment provides that the pressure or spring element is provided or arranged on the closure element. Seen in the longitudinal direction under the magnets, i.e. closer to the base of the closure element. The pressure or spring element can be designed as a plastic positioning knob protruding from the surface. The positioning knob can, for example, be inserted into a hole in the closure element.

According to another embodiment, the pressure or spring element is a spring which is used simultaneously for the lateral and radial positioning of the cutting edge and for pressing the closure element onto the centrifugal wedge jaws.

The centrifugal wedge advantageously has a front wedge surface, which is oriented to the first side wall of the groove, and a back surface opposite the wedge surface, which is oriented to the second side wall of the groove and which takes an acute angle to the front wedge surface. The wedge surface preferably has a groove-shaped depression running in the axial direction. The deepening has the advantage that the Contact pressure is concentrated on the areas of the centrifugal wedge adjacent to the depression.

An elevation extending in the axial direction is advantageously provided on the wedge surface. The survey, e.g. an elongated bead can ensure a positive fit with the closure element.

A first contact surface is expediently provided above the recess and a second contact surface below the recess with a minimum width of at least 1 mm, preferably of at least 2 mm, and particularly preferably of at least 3 mm.

The first side wall of the groove preferably has an angle between 0 and 40 degrees, preferably between 15 and 35 degrees and particularly preferably between 20 and 30 degrees, with a radial extending from the center of the tool head.

The bottom of the centrifugal wedge is advantageously designed with a step that preferably extends parallel to the longitudinal axis of the bore, so that there is a first bottom surface adjacent to the front wedge surface and a second bottom surface adjacent to the back surface. The second floor surface forms an angle> 90 degrees with the back surface, preferably between 90.1 and 95 degrees and particularly preferably between 90.5 and 94 degrees. This physical design of the centrifugal wedge has the advantage that a tilting movement of the centrifugal wedge can be caused when the tool holder is released.

A centering pin (e.g. press fit) can be embedded in the first groove wall for the lateral centering of the cutting insert and, if applicable, the closure element.

According to a particularly advantageous embodiment, a third positive connection is provided between the centrifugal wedge and the closure element for the lateral centering of the closure element. This is a particularly advantageous embodiment which, in conjunction with the second positive connection, enables the radial and axial adjustment of the cutting insert.

A cutting plate for the tool head of a woodworking machine according to one of claims 1 to 4 has a cutting edge on a first side (knife chest) of the cutting plate and a positioning groove on the second side of the cutting plate opposite the cutting edge. This cutting plate is characterized in that the edge of the cutting plate diagonally opposite the cutting edge has a functional surface in the form of a chamfer or a rounding, the depth of which is preferably at least 15% of the cutting plate thickness. This insert has the advantage that it can be positively fixed directly in the tool body. The chamfer is advantageously ≥ 0.6 mm. This chamfer, which is significantly larger than known cutting inserts, has the advantage that an elastically deformable pressure element can spread when the centrifugal key is tensioned due to the increased free space between the groove wall and the cutting insert. The enlarged chamfer therefore has a meaning in connection with the correct radial positioning of the cutting insert. In addition, this functional surface is also relevant in terms of safety, since without it the brittle cutting inserts could break during clamping and fly away during operation.

Preferably, only a single positioning channel is provided, the lower edge of which is at a distance of <10 mm and preferably <8 mm from the cutting surface of the insert.

It is also important that the positioning channel is located within a clamping area. This clamping area is limited on the one hand in depth by the shoulder of the first groove wall and on the other hand in height by the apex of the top surface of the centrifugal wedge and the first pressure surface of the centrifugal wedge.

The cutting plate advantageously has at least one U-shaped recess for lateral positioning. The insert can also have no U-shaped exception. The lateral positioning can then take place, for example, by means of two lateral positioning elements, between which the cutting plate is arranged.

The present invention also relates to a method for inserting and clamping a cutting insert in a holder of a tool head according to the preamble of claim 5, in which method the closure element is held in a form-fitting manner by the centrifugal wedge after being inserted into the tool holder.

In the change position, the locking element can be held by the centrifugal wedge, and the tool in the clamping position by a positive connection with a side wall.

The centrifugal wedge is advantageously moved into the clamping and changing position with the aid of a clamping screw. The advantages associated with the aforementioned method variants have already been discussed above in the discussion of the tool head according to the invention.

The insert is advantageously clamped in the direction of the centrifugal force by means of a clamping screw acting on the centrifugal wedge. This has the advantage that the centrifugal forces acting during the operation of the rotating tool head no longer cause any displacement of the centrifugal wedge. The consequence of this is higher precision when machining the workpieces.

Before the final clamping position is reached, the cutting plate is preferably pressed outward in the radial direction against a stop. This has the advantage that the cutting insert is positioned exactly in the tool holder and cannot slip during operation.

The tool is advantageously positioned or reached before reaching the final position with the aid of an elastic element. brought to a stop with a stop bar.

The insert is advantageously releasably pulled to the closing element in the changing position. This is expediently done with the aid of a magnet, which can be arranged on the closure element or the centrifugal wedge.

According to a particularly advantageous variant of the method, the centrifugal wedge is loosened with the help of the clamping screw. In contrast to the prior art, the centrifugal wedge can be released without a hammer.

The locking element is advantageously held positively by the centrifugal wedge in the tool change position.

The cutting plate is advantageously clamped to the stop and in the direction of flight.

The tool head described above is further characterized in that a spring element can be provided in the tool holder, which presses an insert inserted into the tool holder in the radial direction outward against a stop. A tool head designed in this way has the great advantage that the tool is automatically positioned radially when it is clamped in that the spring means automatically brings it radially outward and stops it with a projection on the tool. This ensures exact positioning of the inserts in the tool holder without additional effort.

The spring element can be a spring or an elastically deformable plastic or metal part which preferably engages in a recess in the cutting insert or engages on the cutting edge.

To position a cutting insert in a tool holder of the tool head, a cutting insert inserted into the tool holder can be pressed against a stop with the aid of a spring element provided and appropriately aligned in the tool holder, in that the spring element exerts a radially outward force on the cutting plate. It is important that the Positioning takes place automatically when the tool is clamped. The spring element can provide radial, lateral or lateral and radial positioning.

Figur 1:

Eine Teilansicht eines ersten Ausführungsbeispiels einer einzelnen Werkzeugaufnahme eines Werkzeugkopfes mit einem mittels eines Verschlusselements und einem Fliehkeil eingespannten Schneidplatte (Arbeitsposition) in einer Seitenansicht;

Figur 2:

Eine Ansicht wie in Fig. 1, wobei die Schneidplatte sich in der Wechselposition befindet;

Figur 3:

Eine Seitenansicht des ganzen Werkzeugkopfes, wobei die Schneidplatte sich in der Wechselposition befindet;

Figur 4:

Eine Stirn- und eine Seitenansicht des Fliehkeils;

Figur 5

Eine Vorder- und eine Seitenansicht des Verschlusselements;

Figur 6

Eine Vorder- und eine Seitenansicht einer als (Profil-)Messer ausgebildeten Schneidplatte;

Figur 7

Eine Schraube mit zwei Gewindeabschnitten zum Spannen und Lösen des Fliehkeils;

Figur 8

Eine weitere Ausführungsform eines erfindungsgemässen Fliehkeils;

Figur 9:

Eine weitere Ausführungsform eines erfindungsgemässen Verschlusselementes mit einer Querrille im Abstand vom Messergrund und einer Positionierhilfe;

Figur 10:

Zwei weitere Ausführungsformen einer Schneidplatte in Gestalt eines Profilmessers in Vorder- und Seitenansicht, wobei die Schneidplatten sich in den länglichen Vertiefungen unterscheiden;

Figur 11:

Eine Teilansicht eines zweiten Ausführungsbeispiels einer einzelnen Werkzeugaufnahme eines Werkzeugkopfes mit einem Fliehkeil gemäss Figur 8 und einem elastischen Druckelement zur Positionierung der Schneidplatte in der Werkzeugwechselposition;

Figur 12:

Der Werkzeugkopf von Figur 11 mit der Schneidplatte in der (gespannten) Arbeitsposition;

Figur 13:

Eine Teilansicht eines dritten Ausführungsbeispiels einer einzelnen Werkzeugaufnahme eines Werkzeugkopfes mit einem modifizierten Druckelement und einem kurzen Verschlusselement; und

Figur 14

Der Werkzeugkopf von Figur 13 mit der Schneidplatte in der (gespannten) Arbeitsposition;

Figur 15:

Eine Teilansicht eines vierten Ausführungsbeispiels einer einzelnen Werkzeugaufnahme eines Räumer - Werkzeugkopfes mit einer kurzen Schneidplatte;

Figur 16:

Der Werkzeugkopf von Figur 15 mit der Schneidplatte in der Werkzeugwechselposition;

Figur 17:

Ein weiteres Ausführungsbeispiel eines Werkzeugkopfes in Gestalt eines Abplattmesserkopfes;

Figur 18:

Ein nicht erfindungsgemäßes Ausführungsbeispiel eines Werkzeugkopfs, bei dem die Spannschraube ein Spannstift ist, der sich mit einem Kopf am Nutengrund abstützt;

Figur 19:

Eine Ausführungsform eines Federelements, das beim Einspannen des Werkzeugs für die radiale Positionierung der Schneidplatte sorgt.

Figur 20:

Das Federelement von Fig. 19, wenn es in die Werkzeugaufnahme eingesetzt und die Schneidplatte durch den Fliehkeil eingespannt ist, in einer vergrösserten Detailansicht;

Figur 21:

Das Federelement von Fig. 19, wenn die Schneidplatte in die Werkzeugaufnahme eingesetzt und der Fliehkeil gelöst ist, ebenfalls in einer vergrösserten Detailansicht.

Embodiments of the invention will now be described with reference to the following Figures 1 to 17 and 19 to 21 described in more detail. It shows:

Figure 1:

A partial view of a first embodiment of an individual tool holder of a tool head with a cutting plate (working position) clamped by means of a closure element and a centrifugal wedge in a side view;

Figure 2:

A view like in Fig. 1 , with the insert in the change position;

Figure 3:

A side view of the entire tool head with the insert in the change position;

Figure 4:

A front and a side view of the centrifugal wedge;

Figure 5

A front and a side view of the closure element;

Figure 6

A front and a side view of a cutting plate designed as a (profile) knife;

Figure 7

A screw with two threaded sections for tensioning and loosening the centrifugal wedge;

Figure 8

Another embodiment of a centrifugal wedge according to the invention;

Figure 9:

Another embodiment of a closure element according to the invention with a transverse groove at a distance from the knife base and a positioning aid;

Figure 10:

Two further embodiments of a cutting plate in the form of a profile knife in front and side view, the cutting plates differing in the elongated recesses;

Figure 11:

A partial view of a second embodiment of an individual tool holder of a tool head with a centrifugal wedge according to Figure 8 and an elastic pressure element for positioning the cutting insert in the tool change position;

Figure 12:

The tool head from Figure 11 with the insert in the (clamped) Working position;

Figure 13:

A partial view of a third embodiment of a single tool holder of a tool head with a modified pressure element and a short closure element; and

Figure 14

The tool head from Figure 13 with the insert in the (clamped) working position;

Figure 15:

A partial view of a fourth embodiment of a single tool holder of a reamer tool head with a short cutting plate;

Figure 16:

The tool head from Figure 15 with the insert in the tool change position;

Figure 17:

Another embodiment of a tool head in the form of a flattening knife head;

Figure 18:

An embodiment of a tool head, not according to the invention, in which the clamping screw is a clamping pin which is supported with a head on the groove base;

Figure 19:

An embodiment of a spring element that ensures the radial positioning of the cutting insert when the tool is clamped.

Figure 20:

The spring element from Fig. 19 when it is inserted into the tool holder and the cutting insert is clamped by the centrifugal wedge, in an enlarged detail view;

Figure 21:

The spring element from Fig. 19 when the cutting insert is inserted into the tool holder and the centrifugal wedge is released, also in an enlarged detail view.

In the Figures 1 to 7 A tool head 11 according to the invention is shown for the rotating processing of wood and its components. It has a plurality of tool receptacles 13 distributed over the circumference, in each of which a tool in the form of a cutting plate 15 can be accommodated. A groove 19 narrowing in the radial direction is provided in the tool holder 13, which can run parallel to the axis or at an angle to the axis of rotation 17 of the tool head 11. For clamping the cutting plate 15, which in the example shown by a profile knife 21 ( Fig. 6 ) is formed, a centrifugal wedge 23 and a closure element 25 Closure element 25 lies against the cutting plate 15 and is pressed against the flat side of the cutting plate 15 by the centrifugal wedge 23. The latter is thus in the work or Clamping position clamped between a first groove wall 27 of the tool head 11 and the closure element 25. The tool head according to the invention is distinguished by the fact that the cutting insert can be inserted into the tool holder 13 in the radial direction or can be removed from it again. In addition, the closure element 25 is held in the tool holder 13 without screws. Another special feature is that the centrifugal wedge 23 for all widths in the area of application according to the invention (typically between 7 mm and 150 mm, preferably between 15 and 100 mm) is tensioned by a single screw 29. is released, ie that no hammer is required to loosen the tool holder, as is usually the case with conventional tool heads. The above-mentioned special features of the tool head according to the invention are explained in more detail with reference to the following description.

As already mentioned above, the groove 19 is narrowed in a wedge shape in the radial direction, i.e. the first groove wall 27 and a second groove wall 31 opposite the first groove wall 27 are inclined towards one another. The centrifugal wedge 23 is received in the groove 19. The dimensioning of the centrifugal wedge 23 and the groove 19 is preferably such that the centrifugal wedge - in the absence of the closure element 25 - can be inserted into the groove 19 in the radial direction. However, it is also conceivable that the dimensioning of the centrifugal wedge 23 and the groove 19 is such that only a lateral insertion is possible. Both embodiments are equally possible within the scope of the present invention.

The centrifugal wedge 23 has a front wedge surface 33, which bears against the closure element 25, and a back surface 35, which bears flat against the second groove wall 31. If no closure element is provided, the front wedge surface 33 bears directly on the cutting plate. The front wedge surface 33 is interrupted by a recess 37 running in the longitudinal direction of the centrifugal wedge 23, so that a first pressure surface 39 is present above the recess 37 and a second pressure surface 41 is provided below the recess. The second pressure surface 41 has an elevation 43 in the form of a bead running in the longitudinal direction, which enables a positive connection with a corresponding, complementarily shaped recess 47 of the closure element 25.

The bottom of the centrifugal wedge 23 is stepped, so that there is a first bottom surface 49 adjacent to the front wedge surface 33 and a second bottom surface 51 adjacent to the back surface 35. First and second bottom surfaces 49, 51 are separated by a step 53, which preferably extends essentially parallel to the back surface 35. The second bottom surface 51 forms an angle of 90 degrees or more, preferably between 91 and 93 degrees, with the back surface 35. As a result, the centrifugal wedge 23 can be tilted in the change position, as will be explained in more detail below.

For the purpose of reducing weight, one or more elongated holes 55 arranged at a distance from one another can be provided in the centrifugal wedge 23. Between the elongated holes 55 there is a screw hole 57 with a longitudinal axis 59, which extends from the top surface 61 to the second bottom surface 51. The longitudinal axis 59 of the screw hole 57 extends essentially parallel to the back surface 35. The screw hole 57 has an internal thread 63 for receiving a rear threaded section 99 of the screw 29 ( Fig. 7 ).

Analogous to the bottom surface 49, 51 of the centrifugal wedge 23, the bottom of the groove is also stepped. It comprises a first groove base surface 65, which corresponds to the second base surface 51 of the centrifugal wedge 23, and a second groove base surface 67, which corresponds to the first base surface 49. A screw hole 69 with an internal thread 70 is provided in the first groove base surface 65. The screw hole 69 is collinear with the longitudinal axis 59, so that by turning the screw 29 the centrifugal wedge 23 from an upper clamping position, in which the closure element 25 and the cutting plate 15 are pressed firmly against the first groove wall 27, into a lower tool change position, in which the Cutting plate 15 can be removed in the radial direction, is movable.

While - as already mentioned above - the bottom surface 51 forms an angle of 90 90 degrees with the back surface 35, the angle between the first Groove base 65 and the back surface 31 preferably about 90 degrees. If the bottom surface 51 forms an angle of> 90 degrees with the back surface 35, when the tool holder is opened, the second bottom surface 51 of the centrifugal wedge 23 comes into contact with the first groove base surface 65 near the step 53. This acts on the centrifugal wedge 23 when it is reached a transverse force into the tool change position, which causes the centrifugal wedge 23 to tilt due to the existing tolerances of the screw threads ( Fig. 2 ). The closure element 25 and the cutting plate 15 are released from the first side wall 27.

A special feature of the closure element 25 is that at least one, but preferably two or more, magnets 69 are provided in the lower region ( Figure 5 ). These are preferably received in recesses 71 flush with the adjacent surface of the tool. The magnets 69 serve to hold the cutting plates 15, which are usually made of a weakly magnetizable material, adhering to the closure element 25, in particular when changing tools, so that the same can be removed more easily.

Just above the recess 47, two elastically deformable plastic knobs 73, in particular those made of an elastomeric material, are provided in the closure element 25 at a distance from one another. These can be inserted into corresponding holes 75 in the closure element 25. The knobs 73 have the purpose of pushing the cutting plate 15 upward when tightening. The mode of operation of the knobs 73 is described in more detail below.

A U-shaped recess 77 is provided in the center of the rear fastening section for the lateral centering of the closure element 25 in the groove 19. In the clamping position, an axially adjustable centering pin 79 engages in this recess 77 and is received in a pin hole 81 of the tool head body ( 1 to 3 ). The pin hole 81 is machined into the tool head body at an angle to the first groove wall 27.

Just above the pin hole 81, only a single groove 83 is provided in the first groove wall 27. A stop bar 85 is received in a form-fitting manner in this groove 83. The groove 83 and the corresponding stop bar 85 can Cross-section quadrangular or polygonal or round. The stop bar 85 cooperates in the clamping position for a precise positioning with a groove 87 in the cutting plate 15 ( Fig. 6 ). This groove 87 is a certain distance, preferably at least 5% and particularly preferably at least 10% wider than the stop bar 85. The groove 87 is advantageously between 20% to 80% wider than the stop bar. In specific exemplary embodiments, the groove 87 is between 30% and 60% wider than the stop bar 85. It is conceivable that instead of the stop bar 85, a corresponding elongated stop 85a is formed directly in the groove wall 27.

The cutting plate 15, according to Fig. 6 is designed as a profile knife 21, can have a U-shaped recess 89 in the center of the tool base and analogous to the closure element 25, which serves to center the cutting plate 15. When the cutting plate 15 is inserted into the groove 19, the head of the centering pin 79 engages in the U-shaped recesses 77, 89 of the closure element 25 and the cutting plate 15, so that they come to lie exactly one above the other. The cutting tip has a cutting edge 92 on the cutting tip face 90. A functional surface in the form of a chamfer 94 is formed on the edge diagonally opposite the cutting edge 92.

Like that 1 to 3 can be removed, the first groove wall 27 is not a straight surface, but has a shoulder 91 at a distance from the groove base, against which the cutting plate can rest. The rear (recessed) wall section above the shoulder 91 is designated in the present case with the reference number 93 and the front (upstream) wall section with the reference number 95. The shoulder 91 has a depth which essentially corresponds to the thickness of a cutting plate 15 to be clamped. When the cutting plate 15 is inserted, the cutting plate face is thus essentially flush with the front wall section 95.

Within the scope of the present invention, the groove 19 denotes those sections of the tool holder which cooperate in the tool holder. The groove 19 accordingly has first and second groove walls 27 and 31 of unequal length.

The rear wall section 93 of the first groove wall 27 above the shoulder 91 can be inclined slightly inwards relative to the front wall section 95 and can assume an angle of up to 5 degrees (see FIG. Fig. 3 ). In this way, the tool can be biased even more strongly against the groove wall 27 in the front region.

The screw 29 for tensioning and loosening the centrifugal wedge 23 is preferably a threaded pin with a front and a rear threaded section 97, respectively. 99 trained ( Fig. 7 ). At the back, the screw has an attack means 101 for a tool, for example an internal square or hexagon or a Torx® thread drive. The front and rear threaded section 97.99 are separated from one another by a constriction 103. The front threaded section 97 is designed to cooperate with the internal thread 70 of the screw hole 69. The rear threaded section 99, on the other hand, is designed to cooperate with the internal thread 63 of the screw hole 57 formed in the centrifugal wedge 23. A special feature of the screw connection described is that the front and rear threaded sections 97.99 have opposing screw threads. According to a preferred embodiment, the front threaded section 97 is a left-hand thread and the rear threaded section 99 is a right-hand thread. This has the advantage that the screw can be turned in the usual direction to tension the centrifugal wedge. The radial position of the centrifugal wedge 23 changes by one thread turn with a full screw revolution.

A further modified embodiment of a centrifugal wedge 23 has a centering element 105 on the wedge surface 33 in the form of a centering knob protruding from the wedge surface 33 ( Fig. 8 ). The centering element 105 serves for the lateral centering of the in the Figure 9 shown closure element 25a by means of positive locking. In contrast to the closure element 25 according to FIG Fig. 5 Instead of a recess 77 in the surface oriented to the centrifugal wedge 23, only a U-shaped recess 107 is formed. This depression 107 extends in the middle of the closure element 25a at a right angle from the base 109 of the closure element 25a (central axis 102). Further differences are that the closure element 25a has no magnets or plastic knobs.

The Figures 11 and 12 show a tool head 11a with the centrifugal wedge 23 and the closure element 25a according to Figure 9 , In contrast to the first embodiment according to the Figures 1 to 7 The tool head 11a has a sleeve-shaped pressure element 113a, which is inserted into an enlarged, front pin hole section 115 of the pin hole 81. The upper edge of the pressure element 113a protrudes from the front wall section 95 on the groove side at the shoulder 91. As in Fig. 11 shown, the pressure element 113a presses in the changing position of the tool holder against the closure element 25a and biases it against the centrifugal wedge 23a. When the cutting plate 15 is clamped, the part of the elastically deformable pressure element 113 a protruding from the wall section 95 is deformed and presses the cutting plate 15 radially outwards and thus against the stop bar 85. This automatically centers the cutting plate 15 in the radial direction. How from Fig. 12 there is a play between the stop bar 85 and the depression 87, ie the depression 87 is wider than the stop bar 85 by a certain amount, preferably between 0.05 and 1.5 mm and particularly preferably between 0.3 and 1.0 mm the insert 15 is loosely inserted into the tool holder and rests on the shoulder 91 ( Fig. 9 ), the upper edge 117 of the stop bar 85 can substantially correspond to the inner side edge 119 of the recess 87.

The embodiment according to the Figures 13 and 14 differs from that of Figures 11 and 12 in that at least one pressure element 113b, but preferably two pressure elements 113b, is received in a separate blind hole 121 which is provided in the area of the shoulder 91 in the tool head body. A blind hole 121 and a pressure element 113b are preferably provided symmetrically on both sides of the centering pin 79. The functioning of the pressure element 113b is the same as that of the pressure element 113a, ie the part of the pressure element 113b protruding from the blind hole 121 and from the wall section 95 causes the cutting plate 15 to be centered radially when clamped. A further modification of this embodiment is in the area of the lateral positioning the insert 15 located. The cutting plate 15 has no U-shaped recess for the lateral positioning. For lateral positioning, the positioning pin 79 is axially outside the cutting plate 15 moved so that the cutting plate 15 can be struck on the left or right side of the positioning pin 79.

The Figures 15 and 16 show a further tool head 11c, in which the tool holder 13a represents a less deep cut than in the tool heads described above and the cutting plate 15a has only a small height and two cutting edges 92a, 92b. Correspondingly, the closure element 25c is also shorter than in the other exemplary embodiments. In contrast to the tool heads described above, the tool head 11c has a stop bar 85a which is integral with the tool body. A centering pin is also not arranged in the center, but rather a lateral stop for the lateral centering of the cutting plate (not shown in the figures). Otherwise, the tool head 11c corresponds in terms of function and structure to the other tool heads, so that a more detailed description can be dispensed with.

The tool head 11d according to Figure 17 represents a flattening knife head, which differs from the previously described embodiments in that the tool holder 13 is not provided in the circumference but in the end face 123 of the tool head 11d. Due to this construction, the centrifugal forces generated when the tool head is rotating only act to a small extent on the closure element 25 and the cutting plate 15. In order to keep the centrifugal wedge 23 precisely in the groove 19, two spaced-apart reinforcing elements 125 projecting from the wall are provided in the groove wall 31 and cooperate in a form-fitting manner with corresponding grooves 127 in the centrifugal wedge 23.

According to the tool head 11e Fig. 18 a modified clamping mechanism is shown. This differs from those described above in that the clamping screw 29a only has a rear thread 99. A head 129 is provided on the front of the tensioning screw 29a and is supported on the groove base 65, 67. In addition, a centering extension 131 is formed on the head 129, which engages in the screw hole 60, which in this case does not have to have an internal thread. In principle, the centering extension can also be dispensed with, since it is not required for clamping the insert. The described embodiment of a tool head is otherwise not provided with a closure element, but the centrifugal wedge 23 acts directly on the cutting plate 15. The embodiment according to Fig. 18 does not fall under the invention according to claim 1 and claim 5. Die Figures 19 to 21 show an embodiment of a spring element 133, on the one hand, the function of the centering pin described above (see. Fig. 3 ) for the lateral alignment of the insert and on the other hand the pressure element for the radial positioning of the insert. The spring element 133 has a rear clamping section 135, comparable to a heavy-duty clamping pin, which can be inserted into the pin hole 81. A spring tongue 137 is formed on the tensioning section 135 with a terminal lug 139 which, when inserted into the pin hole 81, projects beyond the front wall section 95. As in the 20 and 21 shown, the spring tongue 137 presses with the nose 139 onto the closure element 25, pushes it away and thus facilitates the removal of the cutting plate 15 when the centrifugal wedge is released Fig. 21 ). The tool head according to the invention is used as follows: To insert a new cutting insert into the tool head according to the Figures 1 to 3 the centrifugal wedge 23 is first brought into abutment with the base of the groove by turning the clamping screw as far as possible in the corresponding direction of rotation. In the tool change position then assumed, the centrifugal wedge 23 is tilted with respect to the first groove wall 27, so that a gap which opens in the radial direction is formed between the closure element 25 and the rear wall section 93 of the groove wall 27 ( Fig. 2 ). The new insert can now be inserted into the gap, the centering pin 79 ensuring the correct lateral centering of the insert 15. In the position now assumed, the cutting plate 15 rests on the shoulder 91. The elastically deformable pressure elements 73, 113a, 113b can also touch the base of the insert or be arranged at a short distance from it. If the screw 29 is now rotated in the clamping direction, the pressure elements 73, 113a, 113b are clamped between the front wall section 95 and the closure element. These expand laterally and push the cutting insert radially outward, so that the cutting insert rests with the lower edge 100 of the groove 87 on the stop bar 85. The position of the groove 87 and in particular of the lower edge 100 plays in relation to the cutting surface 108 an important role. This is the only way to ensure that the expansion of the pressure elements when clamping the tool is sufficient to ensure exact positioning of the cutting plate in the radial direction during the clamping process. In this way, an exact positioning of the cutting plate in the radial direction is ensured, which significantly increases the accuracy of the work to be carried out. The screw 29 is rotated until the centrifugal wedge lies firmly against the closure element 25. The centrifugal force generated when using the rotating tool head increases the clamping force.

The tool head according to the invention is used, in particular, for the machining of wood, plastic and similar materials, in which the method for processing and for removing chips or particles is similar. Similar materials are, for example, cork, bone, plastic, light metal alloys, wood-based materials such as chipboard, fibreboard, plywood, etc. Cutting plates with a straight, convex or profiled cutting edge are used as tools. The inserts consist of flat blades with a thickness between approximately 1 mm and 3 mm. The cutter head is rotatably arranged in operation on a spindle of a woodworking machine, and further cutter heads can be attached directly adjacent to the spindle. According to one aspect of the invention, the centrifugal wedge (tensioning and loosening) can be adjusted by means of a single screw for all application widths. The cutting insert is already pressed against the stop bar 85 in the direction of flight during clamping, so that the cutting insert can no longer move when the tool head is rotating.

In the above description, the exemplary embodiments are each described by way of example with reference to a tool head which is circular-cylindrical in section, in which the tool is received in an axial groove (which is axially parallel to the axis of rotation). In the context of the invention, the tool holder, respectively. However, the groove also runs at an angle to the axis of rotation (eg conical tool head). The groove can thus assume 3 spatial angles relative to the axis of rotation and thereby define a rake angle, offset angle and axis angle.

Legend

11, 11a-d

tool head

13

tool holders

15

cutting board

17

Rotation axis of the tool head

19

groove

21

profile knife

23

centrifugal wedge

25

closure element

27

first wall of the groove

29

screw

31

second wall of the groove

33

front wedge surface

35

backrest

37

deepening

39

first pressure surface

41

second pressure surface

43

Bead on centrifugal wedge 23

47

Axial recess of the closure element

49

first floor area

51

second floor area

53

step

55

slots

57

screw hole

59

longitudinal axis

61

ceiling surface

63

Internal thread of screw hole 57

65

first groove base

67

second groove base

68

magnet

69

screw hole

70

Internal thread of screw hole 69

71

Cut-out for holding a magnet 68

73

Pressure element in the form of a knob

75

Holes in the tool for receiving the knobs 73

77

U-shaped recess in the closure piece

79

centering

81

pinhole

83

Groove for receiving the stop bar 85

85,85a

stop bar

87

elongated recess in the insert, positioning channel

89

U-shaped recess in the insert

90

Insert chest

91

Heel of the first groove wall

92

cutting edge

93

rear wall section

94

Functional surface on the cutting plate 15 as a chamfer or rounding

95

front wall section of the groove 19

97

front threaded section of the groove 19

99

rear thread section

100

lower edge of groove 87

101

Attack means on screw 29

102

central axis

103

Constriction on screw 29

105

Centering element, centering knob on centrifugal wedge 23

107

Recess in the closure element 25a

108

Base of the insert

109

Reason of the closure element 25, 25a

111

Central axis of the closure element 25a

113a, 113b

Different versions of the pressure element

115

Extended pin hole section

117

upper edge of the stop bar 85

119

top edge of groove 87

121

Blind hole for pressure element 113b

123

End face of the tool head 11d

125

Reinforcing elements for flattening knife heads

127

Grooves in the centrifugal wedge 23 for receiving the reinforcing elements 125

129

Head of the tension screw 29a

131

centering

133

spring element

135

clamping section

137

spring tongue

139

Nose of the tongue

Claims (16)

1. Tool head (11, 11a, 11b), particularly for a woodworking machine, having a cylindrical, conical or profiled main part,

   - which has at least two tool mounts (13) which are preferably evenly distributed over its circumference, for receiving a cutting insert (15),

   - wherein the tool mounts (13) comprise a respective groove (19) which tapers in the radial direction and in which a respective cutting insert (15) can be clamped between a first side wall (27) of the groove (19) and a closure element (25) of the tool head (11, 11a, 11b), and

   - provided between the cutting insert (15) and the first side wall (27) is a first positive locking connection (85, 85a, 87), and

   - arranged between the closure element (25) and a second side wall (31) opposite the first side wall (27) of the groove is a centrifugal wedge (23) of the tool head (11, 11a, 11b),

   characterised in that a second positive locking connection (43, 47) is provided between the closure element (25) and the centrifugal wedge (23).
2. Tool head (11, 11a, 11b) according to claim 1, characterised in that the centrifugal wedge (23) has a hole (57) with an internal thread into which a clamping screw (29) can be introduced, wherein the centrifugal wedge (23) can be moved into the clamping position by turning the clamping screw (29) in a first direction and can be moved into the tool change position by turning the clamping screw (29) in a second, opposite direction.
3. Tool head (11, 11a, 11b) according to claim 1 or 2, characterised in that the closure element (25) or alternatively the centrifugal wedge (23) is provided with at least one magnet (68).
4. Tool head (11, 11a, 11b) according to any one of claims 1 to 3, characterised in that a pressure element or spring element (73, 113a, 113b) is provided which is positioned such that it acts in the radial direction on the cutting insert (15) when the tool is clamped thereby pressing the cutting insert (15) against a stop (85) before reaching the final clamping position.
5. Method for inserting and clamping a cutting insert (15) in a mount of a tool head (11, 11a, 11b), having the following steps:

   - introducing the cutting insert (15) into the gap between a first side wall (27) of the groove (19) and a closure element (25);

   - producing a first positive locking connection between the cutting insert (15) and the first side wall (27) of the groove, and

   - clamping the cutting insert (15) by means of a centrifugal wedge (23),

   further characterised by

   - producing a second positive locking connection (43, 47) between the closure element (25) and the centrifugal wedge (23) when the closure element (25) is inserted into the tool mount (13).
6. Method according to claim 5, characterised in that the cutting insert (15) is clamped in the centrifugal force direction by a clamping screw (29) which engages on the centrifugal wedge (23).
7. Method according to claim 5 or claim 6, characterised in that before reaching the final clamping position, the cutting insert (15) is pressed against a stop (85).
8. Method according to any one of claims 5 to 7, characterised in that the cutting insert (15) is positioned radially by means of a resilient pressure element (73, 113a, 113b) automatically when clamping the tool.
9. Tool system having a tool head according to any one of claims 1 to 4 and a cutting insert (15), wherein the cutting insert (15) has the following features:

   - a cutting edge (92) formed on a first side of the cutting insert (15),

   - a recess (87) which serves as a positioning channel and is provided on the second side, opposite the cutting edge (92), of the cutting insert (15), and

   - a functional surface, diagonally opposite the cutting edge, in the form of a bevel (94) or a rounding.
10. Tool system according to claim 9, characterised in that the bevel (94) is greater than 0.6 mm, seen in the cutting insert thickness.
11. Tool system according to claim 9 or 10, characterised in that the positioning channel (87) is between 30% and 60% wider than a stop ledge (85) provided in the tool mount (13).
12. Tool system according to claim 9 or 10, characterised in that the positioning channel (87) can be angular, semicircular or V-shaped
13. Tool system according to any of claims 9 to 12, characterised in that only a single positioning channel (87) is provided, the lower edge (100) of which is located in a distance of < 10 mm and preferably < 8mm from the base surface of the cutting inserts.
14. Tool system according to any of claims 9 to 13, characterised in that the cutting insert (15) comprises a U-shaped recess for lateral positioning.
15. Tool system according to any of claims 9 to 13, characterised in that with cutting insert (15) without a U-shaped recess a positioning pin (79) is arranged such that the cutting insert (15) can be struck either on the left-hand side or on the right-hand side of the positioning pin 79.
16. Tool system according to any of claims 9 to 15, characterised in that the cutting insert (15) is a flat blade with a thickness between about 1 mm and 3 mm.

Images