DE102009012494A1 - Milling tool with exchangeable polycrystalline diamond inserts - Google Patents

Abstract

The milling tool according to the invention for machining wood materials consists of a support body (1) arranged on this, interchangeable and in four cutting positions (5a, 5b, 5c, 5d) rotatable, flat cutting plates (5) consisting of a hard metal support plate (8) and one on this sintered DP layer support (9), provided with a through-hole (13) for the cutting plates (5) associated fastening elements (10). In this case, the fastening elements (10) are designed in such a way that a positive position determination and a frictional connection of the cutting plate (5) by an annular head support surface (15) with subsequent annular groove (17) without contact of the fastener (10) with the DP Ring edge (20) of the DP surface (16) is formed, and that the position of the cutting plate (5) in the support body (2) through the through-hole (13) designed as a passport (12) fastener (10) together with the contact surfaces ( 23, 24) of the abutment surface (22) of the support body (2) and the convex contour (5b) of the cutting plate (5) is determined.

Description

The Invention relates to a tool consisting of a support body, Cutting slats and associated fasteners for the use on milling machines for circumferential milling of narrow surfaces of wood-based panels.

From GBM No. 20 2007 006 878.6 a tool is known, which removable plates of polycrystalline diamond, hereinafter referred to ISO 513: 2004 Called DP carries. DP cutting battens are typically made of a cemented carbide substrate, for example, 1 mm to 2.6 mm thick, and a flat, sintered, industrial diamond overlay, 0.3 mm to 0.6 mm thick. A design feature of the known tool design described in the aforementioned GBM is that the DP insert has a central hard metal core which receives a central through-hole for a fastener to which the DP insert is connected to the support body. The hard metal core extends in this tool design so far outside the penetration hole, that the head of the fastener for applying the clamping force presses only this hard metal core. By this measure cracking is avoided on the fracture-sensitive polycrystalline diamond.

It The object of the present invention is an improved milling tool in which the tendency to crack of the polycrystalline Diamonds is further reduced.

These Task is by the milling tool with the claim 1 specified characteristics solved. The dependent claims relate to advantageous embodiments and developments the invention.

In a continuation of GBM No. 20 2007 006 878.6 according to the invention by design measures on the fastener even this cracking avoided, when the cutting insert made of diamond-cemented carbide composite has a full-surface Layer of polycrystalline diamond carries. The advantage This insert design is justified in the new Cutting technology of DP plates with laser beams, using non-linear cutting tip geometries even with very hard cutting materials such as the DP extremely fast, d. H. be made in a few minutes. Separates this a laser cutting blades with convex cutting edge line and Through hole from a DP plate blank, more common Diameter 74 mm, off. A time-reduced finishing of a such pre-profiled cutting edge closes for their stand-optimized preparation, for example by means of Rotary erode on. The production of a DP indexable insert from large, flat DP-HW composite panels is therefore an economical method to use with these slitting tools for milling wood materials with constant cutting diameter to design.

The Advantages of these constant diameter tools lie in the elimination Machine setup and subsequent trial cuts, but especially in the mixed assembly of shank tools and cutter heads with tungsten carbide and DP indexable inserts, adaptable to the abrasiveness of the milled Wood or wood composite material. Little abrasive wood layers like For example, spruce and pine plates milled economically and high quality the cutting mat made of carbide with smaller Wedge angle, while the abrasive coatings, hardboard or chipboard layers with the polycrystalline cutting slats Diamond can be milled with a tool. Schneidplattenart and workpiece type correspond to plane-oriented.

The Reproducibility of the position of the cutting edge of the DP cutting mat in the milling tool is a prerequisite for the cutting quality, which reaches the machined cut surface of the wood workpiece becomes. Quality features on the workpiece are the Dimensional accuracy, the non-level surface structure by successively engaged cutting battens, the tear-free at the cutting edge, especially in coatings, and smoothness the narrow surfaces produced with this milling tool of sheet materials, for example coated chipboard, Medium density fiberboard, plywood and laminates.

One constant cutting diameter is in the inventive Milling tool for woodworking by the Design of the insert seat for the DP insert in Tragkörper, by the geometry of the cutting mat and the Design of the fastener achieved. A geometry determination the position of the cutting edge of the cutting mat causes a passband the fastener, which tight tolerates the cutting mat holds in its central penetration hole. The fastener is as a high-strength screw, consisting of screw head, for example, with Multi-tooth drive, Passbund, threaded shaft and others below designed features and is in a record seat of a each individual groove of the support body screwed.

In the thickness direction of the cutting mat, this position is force-oriented by the screw biasing force from the support surface of the screw head to the DP surface of the cutting mat, transferred therefrom to the cemented carbide substrate of the DP cutting mat and thereby effectively on the flat insert seat surface of the individual groove of the support body. The clamping force of the fastener thus acts only on the flat surfaces of the cutting mat. The fit for determining the rotational position of the cutting mat is achieved via the geometry of the crowned narrow-side contour and the adjacent this in the case of installation radial insert seat geometry with an investment function.

To The narrow surface of the cutting mat is contoured in the plate middle plane, preferably in the form of a radius of 80 mm to 200 mm and in the thickness direction conical with a clearance angle of preferably 15 ° to 25 ° with respect to the DP surface designed. According to the invention is designed so Contact surface of the cutting plate in a plane parallel to the plate center plane V-shaped prism shaped seat, which in its vertical extent an identical Ko nicity like the cutting edge narrow surface designed with the clearance angle has.

at This DP insert mounting is combined in a and frictional Schneidkantenlagebestimmung achieved. Are the DP inserts with the fasteners over whose passport is placed centrally defined in the plate seats cause the thicknesswise tapered insert seats and narrow die inserts together with the convex contact contour of the DP inserts and pushing in the V-prism-shaped insert seat contours the inserts in the final investment position at progressive tightening of fasteners until they reach the target torque. The central bolt attachment and the two Investment lines from the V-plate seat and the Schneidplattenballigkeit create a geometrically defined triangle.

There the polycrystalline diamond layer of the DP insert cracked and cracked susceptible to breakage, especially when subjected to tensile stresses reacts, are according to the invention in this milling tool with interchangeable DP inserts Design features to avoid the crack and breakout during assembly of inserts and their use realized. High-speed milling tools for woodworking with exchangeable inserts, used preferably at cutting speeds between tween 20th m · s - 1 and 80 m · s - 1, subject increased stresses from the centrifugal force and must for safety reasons, be designed so that no Cracking occurs.

Of the inventive article has advantageous rotatable DP inserts, with 4 cutting edges in succession after the end of the end of the previously used the machining continue. Therefore, the stockpiled, not yet engaged Cutting edge in waiting position, no installation injury experienced. For this reason, the insert seat for the DP insert is designed so that only the hard metal surface at this Plant comes and the DP narrow area and therefore also the DP cutting edge has no contact with the insert seat. An injury the DP cutting contour by mounting is thus avoided.

injury the DP insert connected with the risk of progressive cracks and the plate break are also at the contact surfaces of Fastener and DP insert possible and become according to the invention by the below Design features of the fastener avoided. Because the Drilling edge of the high-strength DP layer only with high grinding technology Expense can be equipped with a chamfer, owns at this Milling tool the fastener at the transition from the screw head bearing surface to Passport an undercut. In the circumferential at this transition, radial annular groove with rounded groove base, the screw head is just the entire surface on the DP surface. An additional cut-out of the screw head in the axial direction by a so-expanded circumferential groove also provides outside the bore edge the DP layer is circular. This as a variant developed design with extended undercut is elevated Loads of the DP surface from the bolt preload force and the cutting forces of advantage.

A further damage to the bore edge may result The mounting: Is the fastener in the insert seat screwed in and the DP cutting plate is not yet through the Passbund of the fastener centered, can not be excluded be that loading the fracture-sensitive DP surface through the cross-section jump from the threaded shaft to the passband at the edge damaged the DP hole edge. That's why in the milling tool according to the invention the fastener at the transition Passbund threaded shaft provided with a chamfer, which serves as a Einführkegel.

following The invention and selected embodiments of the invention once again shown in an overview.

The milling tool according to the invention for machining wood-based materials consists of a support body, arranged on this, interchangeable and rotatable in four cutting positions, flat cutting battens, consisting of a hard metal support plate and a sintered on this DP layer support, provided with a through-hole for the cutting plates associated fastening elements , The fasteners are designed in such a way that a positive position determination and a frictional connection of the cutting mat by an annular head bearing surface with subsequent annular groove without contact of the fastener with the DP ring edge of the DP surface is formed, and that the position of the cutting mat in the support body through the through-hole for the designed as a passport fastener together with the contact surfaces of the abutment surface of the support body and the convex contour of the cutting mat is determined.

The both contact surfaces of the stop surface can doing an angle for the convex contour of the cutting mat form each other, such that a V-prism-shaped Recording for the convex contour of the cutting mat is created.

The Contact surfaces of the stop surface can have the same convex contour as the contour of the DP insert and therefore have a steady transition.

Especially can the stop surface for the cutting plate a smaller extension in the thickness direction of the cutting mat own as the thickness of the hard metal carrier plate of the cutting mat.

The Fastener may in an advantageous embodiment the invention a Einführkegel in the form of a chamfer of Passbundes own.

Thereby, that the cutting edge corners of the cutting mat are rounded, can Achieved that a clean edge cut without marks is reached in the edge. A similar effect results This is due to the fact that production-related approaches to separation the cutting mat from the DP plate (eg from the approach of an EDM wire) are arranged on the cutting-free cutting edge corner.

In Another variant of the invention has the narrow surface the DP cutting mat has a conical shape to the DP surface, by reducing the diameter of the cutting mat in the thickness direction from the DP surface to the contact surface of the hard metal carrier plate is effected in the single groove of the support body.

Besides can the stop surface of the individual groove of the support body for the installation of the narrow surface of the DP cutting mat in the height extension of the stop surface the Same conicity as the narrow surface of the cutting mat in the thickness direction.

The In addition, ring groove can be inserted through a screw head the fixing element axially surrounding undercut completed be so that the annular groove in the form of the connected radial and the axial groove is widened.

Further yield advantageous embodiments and refinements of the invention to be shown in principle from the below with reference to the drawing Embodiments.

It shows:

1 a perspective view of the tool according to the invention for milling wood materials;

2 a section through an insert half and a fastener half of the milling tool for milling wood materials according to the arrow I from 1 ;

three a further section through an insert half and a fastener half of the milling tool for milling wood materials according to the arrow I from 1 ; and

4 a plan view of cutting mat, fastener and insert seat of the support body according to the arrow II 1 ,

In 1 is a tool 1 shown for milling wood materials, which is intended in particular for milling the narrow surfaces of plates for preparing the coating of these narrow surfaces on plate passing machines for Kantenanleimen. The tool 1 has a central bore for mounting on a machine milling spindle three on the support body 2 on, which as a support for the DP cutting battens 5 is designed.

The supporting body 2 is in the present case with seven, on the circumference of the supporting body 2 arranged grooves 4 provided in which each cutting mat 5 associated, formed as a plate seat Einzelnuten 6 are located. In the present case, the grooves 4 helically shaped. This may be due to the helical groove 4 also a helix 7 connect with opposite slope.

2 shows a section through one half of the cutting mat 5 , consisting of a hard metal carrier plate 8th and the sintered DP layer pad 9 , and through one half of the fastener 10 , which as a screw with a screw head 11 a passport 12 and a threaded shaft 26 is designed. The passport 12 the screw 10 determined after mounting the DP insert 5 with its penetration hole 13 the axis position of the insert 5 , The transition from the passband 12 to the threaded shaft 26 forms a bevel designed as Einführkegel 14 , The transition from the screw head 11 with its headrest surface 15 on the DP surface 16 to the passport 12 is as an annular groove 17 designed. The groove bottom of the annular groove 17 is rounded. The DP insert 5 has on its narrow surface 25 a conical geometry, the machining function of the free surface of the insert 5 assigned.

three shows a cut just like the one in 2 shown, but with a radial 18 and axially 19 circumferential, rounded groove in the screw head 21 of the fastening element 10a , The DP ring edge 20 the DP insert penetration hole 13 gets through this shape of the screw head 21 optional.

4 shows the position of the DP insert 5 in the seat of the single groove 6 of the supporting body 2 with the top view of the screw head 11 of the fastening element 10 and a section of the plan view of the support body 2 perpendicular to the DP layer support 9 , The four cutting edges 5a . 5b . 5c . 5d the cutting plate 5 have a convex contour. The insert seat of the single groove 6 is at its stop surface 22 , corresponding to the convex investment side 5b the cutting mat 5 , as V-prism-shaped contact surfaces 23 . 24 designed. Furthermore, in 4 shown that the cutting edge corners 5c the cutting mat 5 are rounded.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited non-patent literature

• - ISO 513: 2004 [0002]

Claims (10)

Milling tool ( 1 ) for machining wood-based materials, consisting of a support body ( 2 ), arranged at this, interchangeable and in four cutting positions ( 5a . 5b . 5c . 5d ) rotatable, flat cutting battens ( 5 ), consisting of a hard metal carrier plate ( 8th ) and one on this sintered DP layer ( 9 ), provided with a through-hole ( 13 ) for the cutting plates ( 5 ) associated fastening elements ( 10 ), characterized in that the fastening elements ( 10 ) are designed in such a way that a positive position determination and a frictional connection of the cutting plate ( 5 ) by an annular head support surface ( 15 ) with subsequent annular groove ( 17 ) without contact of the fastener ( 10 ) with the DP ring edge ( 20 ) of the DP surface ( 16 ) and that the position of the cutting mat ( 5 ) in the supporting body ( 2 ) through the through-hole ( 13 ) for the passport ( 12 ) designed fastener ( 10 ) together with the contact surfaces ( 23 . 24 ) of the stop surface ( 22 ) of the supporting body ( 2 ) and the convex contour ( 5b ) the cutting mat ( 5 ) is determined. Milling tool according to claim 1, characterized in that the two contact surfaces ( 23 . 24 ) of the stop surface ( 22 ) for the convex contour ( 5b ) of the cutting plate ( 5 ) form an angle to each other, such that a V-prism-shaped receptacle for the spherical contour ( 5b ) the cutting mat ( 5 ) arises. Milling tool according to claim 1, characterized in that the contact surfaces ( 23 . 24 ) of the stop surface ( 22 ) have the same spherical contour as the contour ( 5b ) of the DP cutting mat ( 5 ) and therefore have a steady transition. Milling tool according to one of claims 1 to 3, characterized in that the stop surface ( 22 ) for the cutting mat ( 5 ) a smaller extension in the thickness direction of the cutting mat ( 5 ) than the thickness of the hard metal carrier plate ( 8th ) the cutting mat ( 5 ). Milling tool according to one of claims 1 to 4, characterized in that the fastening element ( 10 ) a Einführkegel in the form of a chamfer ( 14 ) of the Passport ( 12 ) owns. Milling tool according to one of claims 1 to 6, characterized in that the cutting edge corners ( 5e ) the cutting mat ( 5 ) are rounded. Milling tool according to one of claims 1 to 6, characterized in that production-related approaches by separating the cutting mat ( 5 ) from the DP plate at the chip-free cutting edge corner ( 5e ) are arranged. Milling tool according to one of claims 1 to 7, characterized in that the narrow surface ( 25 ) of the DP cutting mat ( 5 ) to the DP surface ( 16 ) has a conical shape, which by reducing the diameter of the cutting mat ( 5 ) in the thickness direction of the DP surface ( 16 ) to the contact surface of the hard metal carrier plate ( 8th ) in the single groove ( 6 ) of the supporting body ( 2 ) is effected. Milling tool according to one of claims 1 to 8, characterized in that the stop surface ( 22 ) the single groove ( 6 ) of the supporting body ( 2 ) for the installation of the narrow area ( 25 ) of the DP insert ( 5 ) in the height extent of the stop surface ( 22 ) the same conicity as the narrow surface ( 25 ) of the cutting plate ( 5 ) in the thickness direction. Milling tool according to one of claims 1 to 9, characterized in that the annular groove ( 17 ) is supplemented by a in a screw head ( 21 ) of the fastening element ( 10a ) axially encircling undercut ( 19 ), so that the annular groove ( 17 ) in the form of the connected radial ( 18 ) and the axial groove ( 19 ) is extended.