EP2060355B1 - Stone saw blade - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to a saw blade with a band-shaped base body and unrestricted teeth with geometrically determined cutting edges, the teeth having molded bodies made of hard metal connected to the base body.

The saw blade has a band-shaped body, so it is designed as a saw blade. The band-shaped base body has seats which are intended to receive shaped bodies made of hard metal. In general, these seats are made by milling the band-shaped body. The shaped bodies made of hard metal are produced as separate elements and permanently connected via the seats with the band-shaped base body. The shaped bodies of hard metal have geometrically determined cutting edges and thus form the teeth of the saw blade.

NEXT STATE OF THE ART

A saw blade is from the German patent application DE 42 00 423 A1 known. The saw blade is designed and intended for machining metallic materials. It has a base body with unrestricted teeth with cutting edges, which are provided in repetitive cycles. The teeth may consist of the moldings connected to the body made of hard metal. Each cycle consists of at least one tooth group consisting of at least three teeth with height and width graduation. The teeth may be from tooth to tooth decreasing height and thereby increasing width. All teeth are formed symmetrically to a longitudinal center plane through the body. The teeth have geometrically determined cutting edges, ie each tooth has a geometrically determined shape with rake angle, clearance angle, etc. The effective cutting or cutting portions of all teeth are each formed by a kinking cutting edge, the inner portion is approximately perpendicular to the longitudinal center plane and connect to the outwardly in a symmetrical arrangement to the base towards inclined chamfers. The cutting edge thus has corners both in the region of the kinking cutting edge and at the transition between chamfer and flank. The cutting edges on each tooth can be changed in shape by increasing the number of breakpoints.

Another saw blade is also from the German patent application DE 199 63 396 A1 known. This saw blade is also used for cutting metallic materials. The number of teeth in the cycle is at least 2. The teeth may consist of the moldings connected to the body made of hard metal. The two teeth have a height and a width grading and form a first group of teeth. On each tooth, an effective cutting edge is formed in the form of a kinking line. It is provided a second group of teeth, each having a straight across the width of the cutting edge. The teeth of the second group of teeth are identical. The teeth of the second group of teeth represent the teeth with the largest width and the lowest height. The teeth of the first group of teeth and the second group of teeth can be arranged alternately.

OBJECT OF THE INVENTION

The invention has for its object to provide a saw blade, which provides a high cutting performance without large loss of material, flexible for the production of workpieces with different dimensions and is suitable for sawing stone.

SOLUTION

According to the invention the object is achieved by a stone saw blade with the features of claim 1.

The shaped articles for sawing stone thus have a support made of hard metal and a layer forming the cutting edge, wherein the layer has a hardness of at least 5,000 HK.

Further state of the art

It is also well known that for the separation of stone, in particular granite, sandstone, marble and the like, and sawing elements are used which have no geometrically determined cutting. For example, wire saws are known in which a circulating cable is used, which is covered with cylindrical segments, wherein the segments are coated with diamond. Such wire saws provide a low cutting performance, can be used only with relatively low feed and work in stone a relatively wide cutting channel, so that in such a separation work, a relatively large loss of material occurs. The producible cuts are rarely straight and provide a relatively large roughness on the cut surface.

It is also well known that for separating stone and cutting discs are used with a relatively large diameter, which advantageously provide a high cutting performance, but disadvantageously work out a correspondingly wide cutting channel in the stone.

It is also well known that horizontal sawing saws are used for sawing stone, which are designed and arranged in their basic structure in itself, as is known in gate saws for wood. However, the saw blades are diamond-strewn, so there are no geometrically determined cutting edges. The disadvantage of such gang saws is determined by the low flexibility and the slice thickness predetermined by the setting.

A tool for milling grooves and folds is from the European patent application EP 0 590 408 A1 known. This document thus shows and describes a milling cutter. An indication of the formation of a saw blade does not contain this document.

A saw blade is from the European patent application EP 0 715 919 A1 known. This document shows a positive connection of the use of the saw blade via a clamping or plug connection with the base body. The inserts can have a surface hardness of at least 1200 HV 30.

A drill is from the German patent application DE 196 52 208 A1 known. This document relates to a drill, in particular for drilling boreholes in hard material, such as Stone. An indication of the formation of a saw blade does not contain this document.

DESCRIPTION OF THE INVENTION

The invention relates to a stone saw blade with a band-shaped base body and unrestricted teeth with geometrically determined cutting edges, the teeth having molded bodies made of hard metal connected to the base body. The shaped bodies have a hard metal carrier and a layer forming the cutting edge for sawing stone, the layer having a hardness of at least 5,000 HK. So it is a stone saw blade.

Under cutting working separation process with a cutting edge with geometrically defined cutting shape are in this application within the meaning of DIN 8580 turning, drilling, milling, planing, broaching, sawing and filing to understand. As a cutting working separation process with a cutting edge with geometrically indefinite cutting edge u. a. To look at grinding, honing and lapping.

The new layer is therefore substantially harder than the carrier of the shaped body of the hard metal. The shaped bodies form the teeth of the saw blade and have a geometrically determined shape with a cutting edge, cutting edge, rake angle, clearance angle, etc. It is sufficient if the layer on the shaped bodies made of hard metal is dimensioned comparatively thin. Important is the extremely high hardness, which is achieved only by a few materials. In particular, the layer may consist of polycrystalline diamond (PCD) or of cubic boron nitride (CBN). Such materials are not used in saw blades. The layer thus has a hardness of at least 5,000 HK (Knoop hardness, see also DIN EN ISO 4545), HK - HV (Vickers hardness) being valid for small loads.

The layer may be provided on the surface of the carrier of the molded body facing forwards in the direction of travel of the strip. The layer forms a rake surface with which the material to be removed and the removed material at least partially come into contact. This includes the cutting edge of the rake face. The use of this layer of extremely high hardness, in conjunction with the formation of the carrier when sawing stone, results in not so much a cutting decrease of chips but rather a hammering or hammering effect. at the smallest areas of the stone smashed and so far removed. The layer protects the wearer of the molding and thus the tooth from wear.

The part of the rake face of the layer which comes into contact with the stone has a round or rounded cutting edge on at least one tooth of a tooth group, preferably on all teeth of the saw blade, in a view opposite to the direction of strip travel. Bending cutting edges, as they are known in the art, are thus not used and corners or sharp Abknickpunkte in the cutting edge come in discontinued. This is according to the invention to refer to the transition between the cutting edge and the back surface but also on the transition to the flank surfaces of the tooth. The round shape avoids corners. It has a rounded shape, which can be formed from adjoining elbows, even with different radii. In a special form, the round cutting edge can be circular.

The shaped body of the hard metal carrier and the layer of high hardness can be defined positively held on the band-shaped body in a milled seat defined. This refers at least to both the radial and the tangential direction. The permanent connection between the moldings made of hard metal and the band-shaped body can be done by common types of connection, such as welding, soldering and the like.

The geometrically determined cutting edges for the new saw blade for cutting stone can in themselves have all the features and advantages of saw blades for cutting metallic materials from the patent applications DE 42 00 423 A1 and or DE 199 63 396 A1 the applicant are known. This includes the use of variable pitch and the placement of different teeth in repetitive cycles. Each cycle should have at least one tooth group of at least three teeth, with a height grading and a width graduation, wherein the height gradation may decrease from tooth to tooth, and the tooth width may also increase from tooth to tooth. It is also possible for a plurality of tooth groups to be intermittently nested on one base body, but at least the teeth of one tooth group should have rounded cutting edges. Another group of teeth may also have rounded cutting edges, but only teeth of identical geometric shape in the group.

The teeth formed by the shaped bodies can have a negative rake angle, in particular approximately between -25 ° and 0 °. The clearance angle can be 0 ° to 15 °. Such a clearance angle refers to the roof surface of a tooth and / or on the formation of the flanks.

But it is also possible that the teeth formed by the moldings have a positive rake angle, but then with a negative protective bevel of about 0 ° to -25 °. Also, it is advantageously achieved a hammering fragmentation of the rock material during sawing.

The rake surface may have a hard material coating on the layer of each shaped body. Aluminum titanium nitride, titanium aluminum carbonitride, chromium nitride or the like are particularly suitable for this purpose. The coating can also be applied as a multilayer structure. It should usually extend over the rake face and also over the cutting edge and part of the flanks on each molding.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the introduction to the description are merely exemplary and can come into effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1

zeigt eine erste beispielhafte Ausführungsform des neuen Sägeblatts in einer Seitenansicht.

Fig. 2

zeigt eine Ansicht der Spitzenbereiche der Zähne entgegen der Bandlaufrichtung.

Fig. 3

zeigt eine Seitenansicht eines einen Zahn mitbildenden Formkörpers.

Fig. 4

zeigt eine Vorderansicht des Formkörpers gemäß Fig. 3.

Fig. 5

zeigt eine zweite beispielhafte Ausführungsform des neuen Sägeblatts in einer Seitenansicht.

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

Fig. 1

shows a first exemplary embodiment of the new saw blade in a side view.

Fig. 2

shows a view of the tip portions of the teeth against the tape running direction.

Fig. 3

shows a side view of a tooth co-forming shaped body.

Fig. 4

shows a front view of the molding according to Fig. 3 ,

Fig. 5

shows a second exemplary embodiment of the new saw blade in a side view.

DESCRIPTION OF THE FIGURES

This in Fig. 1 partially illustrated example new saw blade 1 has a band-shaped base body 2, which has a rectangular cross section in a known manner. The one side of the main body 2 shown carries teeth 3. The teeth 3 are unrestricted and preferably formed and arranged symmetrically to the longitudinal center plane 14 of the base body 2. The teeth 3 have a greater width than the main body. 2

The teeth 3 are formed or formed by shaped bodies 4. Each shaped body 4 consists for the most part of a carrier 21 made of hard metal and has on one side or surface a layer 5 which consists of a material which is harder than the hard metal of the carrier 21 of the shaped body 4. The hardness of the layer 5, which is permanently bonded to the hard metal of the carrier 21 of the molded body 4, is at least 5,000 HK (Knoop hardness, see DIN EN ISO 4545). Suitable materials which exhibit such exceptional hardness are in particular polycrystalline diamond (PCD) or cubic boron nitride (CBN).

The moldings 4 with the layers 5 are inserted into seats 6. The seats 6 and the rest of the shape of the band-shaped base body 2 on the side on which the teeth 3 are mounted, preferably by milling. The moldings 4 are permanently connected to the seats 6 with the material of the base body 2, for example by welding or soldering. The seats 6 are shaped so that each shaped body 4 is placed and held positively in two directions extending at least approximately at right angles to each other. The placement of the molded body 4 is carried out so that the layers 5 point in the direction of tape travel 7.

Out Fig. 1 It can be seen that the shaped bodies 4, which form the teeth 3, are arranged with a negative rake angle 8. The rake angle 8 of all teeth 3 may be formed coincident. But it is also possible that the negative rake angle 8 vary from tooth 3 to tooth 3, so that in this way groups of teeth from z. B. three consecutive teeth 3 are formed, with the negative rake angle repeat 8 at the respective teeth 3 in each group. Negative rake angles 8, in particular between -25 ° and 0 °, are used.

Out Fig. 1 it can be seen that the teeth 3 can also be arranged with variable pitch. The teeth 3 can also be arranged in a height and / or a width graduation. Each tooth 3 has on the running in the direction of tape 7 forward facing free surface of the layer 5, a clamping surface 9, which merges at its upper portion in a cutting edge 10 and ends in this cutting edge 10. The upper portions of the rake surface 9 and the cutting edge 10 together form a respective cutting edge 11. The forming the teeth 3 moldings 4 are arranged with a clearance angle 12, so that there is a back rake surface on each tooth 3.

Fig. 2 shows the relative design of three teeth 3 in their mutual projection against the tape running direction 7 in the region of the cutting edges 11. It is a tooth 3 ₁ recognizable, the counter to the strip running direction 7, a second tooth 3 ₂ follows, in turn, by a tooth 3 ₃ opposite the tape running direction 7 is followed. It can be seen that a group of teeth is preferably formed from at least three teeth 3 ₁ , 3 ₂ , 3 ₃ . This group is repeated in cycles. Each cycle has at least one group, ie three consecutive teeth 3. However, other forms of teeth 3, groups and cycles are possible.

It can be seen that the tooth 3 _{1 has} a rake surface 9 ₁ , which merges at its upper end into a cutting edge 10 ₁ . The cutting edge 10 is formed and arranged in a circular arc and goes to form each corner on the right and left in each case a flank 13 via. The flanks 13 and the associated flank angles coincide on all teeth 3 ₁ , 3 ₂ and 3 ₃ and coincide in the projection.

The following tooth 3 ₂ has a cutting edge 10 ₂ . The shaping reveals that the cutting edge 10 _{2 is} composed of a series of radii so that overall the rounded shape shown results. In the central region, that is, following the longitudinal center plane 14, the cutting edge 10 _{2 has} a straight piece 15 ₂ , in which the radius is therefore infinitely large. At this straight piece 15 ₂ is followed by a respective elbow 16 ₂ , which has a finite radius. Each elbow 16 ₂ finally goes into another elbow 17 ₂ over. The transition between the elbows 16 ₂ and 17 ₂ is preferably carried out with a common tangent. The elbow 17 ₂ runs into the flank 13 almost without a break point.

Also, the third tooth 3 ₃ in the tooth group has a rounded cutting edge 10 _3rd The cutting edge 10 ₃ is also composed here of a straight piece 15 ₃ and two elbows 16 ₃ and 17 ₃ together. The elbow 17 ₃ is arranged and is determined by a radius selected so that it enters tangentially into the flank 13. The transition point is slightly below the point at which the tooth 3 _{3 has} its greatest width. At least one of the teeth 3 ₁ , 3 ₂ and 3 ₃ has such a shape as described with reference to the tooth 3 ₃ . However, it is also possible to make all the teeth 3 in the group of teeth in this way in order to avoid break points at the transitions to the flanks 13.

Out Fig. 2 is also a height and width gradation of the teeth 3 ₁ , 3 ₂ and 3 ₃ recognizable. The tooth 3 ₁ is the tooth with the largest height and smallest width. The tooth 3 ₃ is the tooth with the lowest height and largest width. The tooth 3 ₂ lies in between. The order of the teeth 3 ₁ , 3 ₂ and 3 ₃ in the direction of belt 7 is not mandatory. The teeth 3 ₁ , 3 ₂ and 3 ₃ may have the same or different rake angle 8. The clearance angle 12 at the back of the teeth can also vary. Each tooth 3 ₁ , 3 ₂ and 3 ₃ preferably operates only with the region of its cutting edge 10, in accordance with the projection Fig. 2 survives freely. In this way, strips of material are eliminated in the cutting channel, as is already the case in the prior art described above. The clearing out of the material strips However, it does not spanwise, but more by hammering material fragmentation by the individual strip-shaped areas of the rock material are smashed and smashed in the cutting channel.

In the 3 and 4 a preferred embodiment of the molding 4 is shown. The molded body 4 has the carrier 21 made of hard metal, which carries on one side the layer 5 of PCD or CBN. The layer 5 is thinner, generally substantially thinner, than the carrier 21 of the shaped body 4. The shaped body 4 forms with the free surface of the layer 5, the rake face 9, which merges at its upper end in the cutting edge 10, which, as Fig. 4 shows, is formed here arcuate. In the lower region of the molded body 4 has a recess 18 and a channel whose width corresponds to the thickness of the band-shaped base body 2. Taking into account the design and arrangement of the seats 6 in conjunction with the recess 18 is thus recognizable that each shaped body 4 is defined in all three spatial directions positively secured to the base body 2.

Fig. 5 shows a further embodiment of the saw blade 1 with its base body 2 and three teeth 3 ₁ , 3 ₂ and 3 ₃ in the teeth group. It is understood that the number of teeth 3 in the group of teeth may also be greater or less than three. The teeth 3 ₁ , 3 ₂ and 3 ₃ are arranged here with a positive rake angle 19. The rake angle 19 of the individual teeth 3 ₁ , 3 ₂ and 3 ₃ can be designed to match or even varying. The same applies to the division. However, each rake surface 9 of the layer 5, which is arranged in positive rake angle 19, but goes in its upper region in a negative protective chamfer 20 over. The protective bevel 20 extends within the layer 5. The protective bevel 20 also results in a negative angle in the region of the cutting edge 10, so that even with this embodiment, the intended hammering and shattering effect of the cutting 11 on the rock material is also possible.

Areas of the rake surface 9 and / or the protective bevel 20 including the cutting edge 10 of the layer 5 may be provided with a hard coating 22. This is for clarity only on the tooth 3 ₃ in Fig. 5 shown. The hard material coating 22 may also extend over part of the flanks 13 of the teeth 3. The hard material coating 22 may in particular consist of aluminum titanium nitride, titanium aluminum carbonitride or chromium nitride.

LIST OF REFERENCE NUMBERS

1

sawblade

2

body

3

tooth

4

moldings

5

layer

6

Seat

7

Tape direction

8th

negative rake angle

9

clamping surface

10

cutting edge

11

cutting edge

12

clearance angle

13

flank

14

Longitudinal center plane

15

straight piece

16

elbow

17

elbow

18

recess

19

positive rake angle

20

Protective chamfer

21

carrier

22

Hard Coating

Claims (8)

1. A stone saw blade (1), comprising
   a band-shaped base body (2) and unset teeth (3) having geometrically defined cutting portions (11),
   wherein the teeth (3) include form bodies (4) of hard metal being connected to the base body (2) and including a rear free surface and flank surfaces,
   wherein the teeth (3) being formed by the form bodies (4) have a negative rake angle (8) or a positive rake angle (19) with a negative protecting bevel (20) of between 0° to -25°,
   wherein the form bodies (4) include a carrier (21) of hard metal and a layer (5) forming the cutting portion (11) for sawing stone,
   wherein the layer (5) has a harness of at least 5,000 HK,
   wherein the layer (5) forms the face (9) of the form body (4), and
   wherein the portion of the face (9) of the layer (5) getting in contact with the stone includes a round cutting edge (10) without sharp deviation points in the region of the transition between the cutting edge (10) and the rear free surface and in the region of the transition between the cutting edge (10) and the flank surfaces.
2. The stone saw blade (1) of claim 1, characterised in that the layer (5) is made of PCD or CBN.
3. The stone saw blade (1) of claim 1, characterised in that the round cutting edge (10) is designed to be circular.
4. The stone saw blade (1) of at least one of claims 1 to 3, characterised in that the form body (4) of the carrier (21) of hard metal and the layer (5) is held in a positively engaging way in a seat (6) being produced at the band-shaped base body (2).
5. The stone saw blade (1) of at least one of claims 1 to 4, characterised in that the form bodies (4) forming the cutting portions (11) are provided on the band-shaped base body (2), especially with a variable division, in repeating cycles and each cycle includes at least a group of teeth of preferably at least three teeth (3) having different heights and different widths.
6. The stone saw blade (1) of at least one of claims 1 to 5, characterised in that the teeth (3) being formed by the base body (4) have a negative rake angle (8), especially between -25° and 0°, and/or a clearance angle (12) of between 0° to 15°.
7. The stone saw blade (1) of at least one of claims 1 to 5, characterised in that the teeth (3) being formed by the form bodies (4) have a positive rake angle (19) with a negative protecting bevel (20) of between 0° to -25°
8. The stone saw blade (1) of at least one of claims 1 to 7, characterised in that the layer (5) forms the face (9) of the form body (4) and the face (9) includes a hard material coating (22), especially of aluminum titanium nitride, titanium aluminum carbon nitride or chrome nitride.

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