IL125519A

IL125519A - Saw blade particularly for cutting

Info

Publication number: IL125519A
Application number: IL12551998A
Authority: IL
Original assignee: Arntz Gmbh & Co Kg
Priority date: 1997-08-13
Filing date: 1998-07-27
Publication date: 2002-12-01
Also published as: DE59805165D1; EP0896848A3; JPH11156634A; DE19735143A1; EP0896848B1; EP0896848A2; IL125519A0

Abstract

A saw blade (1) for cutting steel, nonferrous metals or wood and plastics, having a sawblade body (2) on the periphery of which saw teeth (3) are arranged, which project radially outwards and are in each case formed by a saw-tooth base (5) and a cutting insert (6) characterized in that a recess (10) which is open on each side, with a bearing surface (12) which is leading in the direction of rotation (8) and a trailing back mating surface (14) and a bottom surface (13) is formed in the saw-tooth base and the cutting insert is arranged with a frontal surface (25) which is leading in the direction of rotation bearing against the bearing surface and with a back surface (26) facing towards the back mating surface, a clamping device being provided which presses the cutting insert against the bearing surface. 3533 כ" ו בכסלו התשס" ג - December 1, 2002

Description

125519/3 Saw blade particularly for cutting ARNTZ GmbH + Co. KG.

C. 112337.1 Saw blade particularly for cutting The invention relates to a saw blade for cutting steel, nonferrous metals or wood and plastics with cutting inserts arranged on the circumference.

Known saw blades have a circular sawblade body with saw teeth formed on the circumference. The saw teeth are formed by a saw-tooth base which is formed integrally on the sawblade body and a cutting insert which is attached in an unreleasable manner thereto, for example by soldering or welding. In the event of damage to the cutting insert, such as for example fragments breaking off, it is necessary to unsolder the old destroyed cutting insert, to clean the soldering surface, to solder on a new cutting insert and to precision grind its geometry. An extensive range of special machines are necessary to do this and exchanging a cutting insert causes considerable operating outlay.

US 4,563,929 discloses a sawblade for sawing wood which has an extremely rough and large circumference and comprises a sawblade body with segments arranged on the periphery .

Segments which are approximately in the form of a segment of a circle and between them delimit an encircling chamber which is open to the outside in the radial direction, are arranged on both sides of the sawblade body. Radially running shoulders, to which the cutting teeth are attached, are formed on the segments. The bodies of the cutting teeth extend into the space between the segments and are attached to the segments by means of one or two screws. The segments are fixed to the sawblade body by means of further screws. The screw connection between the sawblade body and the segments or between the segments and the saw teeth allows individual saw teeth and segments to be dismantled and repaired or exchanged directly at the insert tube of the saw.

A complex design of this kind with segments arranged on both sides of the sawblade body is only suitable for extremely large saw blades with a diameter of, for example, one metre or more. Owing to the multilayer structure, in the case of smaller saw blades this design would result in an excessive thickness on the circumferential region of the saw blade, which would produce a correspondingly wide saw cut.

The invention is based on the object of providing a saw blade which is of simple and cost-effective design, is of high strength, can be repaired quickly and easily and the saw teeth of which can withstand high saw loads over a long service life.

The object is achieved by means of a saw blade having the features of Claim 1. Advantageous considerations are characterized in the subclaims.

The saw blade according to the invention has a sawblade body with saw teeth arranged on the periphery. The saw teeth are in each case formed by a saw-tooth base and a cutting insert which rests in a recess in the saw-tooth base. The cutting insert has a frontal surface which is arranged to be leading in the direction of rotation and a back surface which is arranged to be trailing in the direction of rotation.

A bearing surface leading in the direction of rotation and a trailing back mating surface are formed in each of the recesses. The cutting inserts fit approximately in a positively-locking manner into the recesses, a clamping device being provided in the region of the back surface and back mating surface, which clamping device applies a predetermined pressure to the cutting - - insert in the direction of rotation of the saw blade. The frontal surface of the cutting insert thus bears against the bearing surface under pressure, and preferably a narrow gap is formed between the back surface and the back mating surface. This preloading pressure serves to compensate for the cutting forces generated on the saw blade in use.

It has been found that the two-part design of the saw teeth, comprising the saw-tooth base and the cutting insert, is able to withstand the impact loads which occur during sawing very well and it is very rare that fragments break off from the teeth or teeth flanks even after prolonged utilization of the saw blade.

The provision of a gap in particular allows a certain flexibility of the cutting insert in the recess of the saw-tooth base, so that an impact load acting on the cutting insert is damped by a bending or tilting movement of the cutting insert before being transmitted to the saw-tooth base and the load is spatially dispersed when it is introduced into the saw-tooth base. In addition, the impact loads are to some extent converted into dry friction and, as a result, are considerably reduced. This leads to a surprisingly high service life of the saw blade according to the invention .

The invention is explained in more detail below by way of example with reference to the drawing, in which: Fig. la shows a side view, partly in section, of a first exemplary embodiment of a saw blade according to the invention in the region of a saw tooth; Fig. lb shows a plan view of the saw blade shown in Fig. la, in the region of a saw tooth; - - Fig. lc - le show a cutting insert of the saw blade shown in Fig. la in cross-section, in rear view and in plan view; Fig. 2a shows a side view of a second exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 2b shows a plan view of the saw blade from Fig. 2a, in the region of a saw tooth; Fig. 2c - 2e show a cutting insert of the saw blade shown in Fig. 2a in cross-section, in rear view and in plan view; Fig. 3a shows a side view of a third exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 3b shows a plan view of the saw blade from Fig. 3a, in the region of a saw tooth; Fig. 3c - 3e show a cutting insert of the saw blade shown in Fig. 3a in cross-section, in rear view and in plan view; Fig. 4a shows a side view of a fourth exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 4b shows a plan view of the saw blade from Fig. 4a, in the region of a saw tooth; Fig. 4c - 4e show a cutting insert of the saw blade shown in Fig. 4a in cross-section, in rear view and in plan view; Fig. 5a shows a side view of a fifth exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 5b shows a plan view of the saw blade from Fig. 5a, in the region of a saw tooth; Fig. 5c - 5e show a cutting insert of the saw blade shown in Fig. 5a in cross-section, in rear view and in plan view; Fig. 6a shows a side view of a sixth exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 6b shows a plan view of the saw blade from Fig. 6a, in the region of a saw tooth; Fig. 6c - 6e show a cutting insert of the saw blade shown in Fig. 6a in cross-section, in rear view and in plan view; Fig. 7a shows a side view of a seventh exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; Fig. 7b shows a plan view of the saw blade from Fig. 7a, in the region of a saw tooth; Fig. 7c - 7e show a cutting insert of the saw blade shown in Fig. 7a in cross-section, in rear view and in plan view; Fig. 8a show a side view of an eighth exemplary embodiment of the saw blade according to the invention, in the region of a saw tooth; - - Fig. 8b shows a plan view of the saw blade from Fig. 8a, in the region of a saw tooth; and Fig. 8c - 8e show a cutting insert of the saw blade shown in Fig. 8a in cross-section, in rear view and in plan view.

A first exemplary embodiment of the saw blade according to the invention is illustrated in Fig. la to le.

The saw blade 1 has an approximately circular sawblade body 2, on the periphery of which saw teeth 3 which project radially outwards are arranged. The saw teeth 3 are in each case formed by a saw-tooth base 5 and a cutting insert 6.

The saw-tooth base 5 is formed integrally on the sawblade body 2, projecting radially outwards and, when viewed from the side, is approximately in the form of a convexly curved hump.

A recess 10, which when viewed from the side resembles a U-shaped groove, with a bearing surface 12, which is leading in the direction of rotation 8, a bottom surface 13 and a trailing boundary surface 14, which is referred to below as the back mating surface 14, is formed in the saw-tooth base 5, in that half of the base 5 which is leading in the direction of rotation 8 of the saw blade 1.

The bearing surface 12 and the back mating surface 14 on the saw blade 1 are arranged approximately in the radial direction and. are perpendicular to the bottom surface 13. At the region trailing the back mating surface 14, the saw-tooth base 5 forms a tooth flank 16 with a convexly curved tooth-flank boundary edge 17.

- - A threaded bore 20, which extends from the tooth-flank boundary edge 17 to the back mating surface 14, is made in the tooth flank 16. The threaded bore 20 is inclined radially inwards in the direction of rotation 8, so that a longitudinal centre axis 21 of the bore 20 includes an angle a with a perpendicular 22 to the back mating surface 14 which lies in the range from approximately 10° to 40° and preferably in the range from 20° to 30°.

At the region leading the bearing surface 12, the saw-tooth base 5 is designed to project less far outwards in the radial direction than the tooth flank 16, so as to form a chip space 18; consequently, the radial length of the bearing surface 12 is approximately half the size of the radial length of the back mating surface 14. The region leading the bearing surface 12 has a chip-space boundary edge 19 which is curved convexly inwards in the radial direction in the direction of rotation 8.

The cutting insert 6 is an approximately cuboid-shaped body with a frontal surface 25 leading in the direction of rotation 8, a trailing back surface 26, two side faces 27, a bottom surface 28 and a land 29 which is arranged opposite to the bottom surface 28.

The frontal surface 25 is relief-ground (Fig. la, lb) in the region of the land 29 and the side faces 27, the edge between the frontal surface or front surface 25 and the land 29 forming a main cutting edge 30 and the edges between the frontal surface 25 and the side faces 22 forming secondary cutting edges 31. The cutting insert 6 is inserted in the recess 10 in the saw-tooth base 5, the bottom surface 28 of the cutting insert 6 bearing against the bottom surface 13 of the recess 10 and the frontal surface 25 of the cutting insert 6 bearing against the bearing surface 12. The main - - cutting edge 30 projects radially outwards on the saw-tooth base 5 and on the cutting insert 6 and, during rotation of the saw blade 1, describes an orbit 33.

A cutout 35 is arranged on the back surface 26 so as to lie opposite the threaded bore 20 (Fig. lc, Id) . The cutout 35 has a planar cutout base 36 and a side wall 37. The cutout base 36 is arranged approximately perpendicular to the longitudinal centre axis 21 of the threaded bore 20. The side wall 37 is formed by a semicircular curve 38 and two vertically adjoining flanks 39.

To fix the cutting insert 6 in the recess 10, a threaded bolt 40 is screwed into the threaded bore 20. The threaded bolt 40 has a front and rear end face 41, 42. A recess 43 for a tool to engage in is formed in the rear end face 42. The front end face 41 bears against the cutout base 36 with preloading. The threaded bolt 40 presses the cutting insert 6 against the bearing surface 12 in the direction of rotation 8, so that the frontal surface 25 of the cutting insert 6 bears against the bearing surface 12 with preloading. Thus the threaded bolt 40 and the cutout 36 act as a clamping device, by means of which the cutting insert 6 is clamped into the recess 10 in the saw-tooth base 5. A gap 45 is formed between the back surface 26 of the cutting insert 6 and the back mating surface 14 of the saw-tooth base 5 by the preloading which clamps the cutting insert 6 into the recess 10.

As a result of the inclination of the threaded bolt 40 through the angle a and the corresponding inclination of the cutout base 36, which is aligned so as to rise in the direction of rotation 8, the cutting insert 6 is also subjected by the threaded bolt 40 to a force component which acts radially inwards. This force component acting radially inwards presses the bottom surface 28 of the cutting insert 6 against the bottom surface 13 of the recess 10. As a result, the radial position of the cutting insert 6 is secured and protected against movement in the radial direction.

When sawing with the saw blade 1 according to the invention, the impact load acting on the saw teeth 3 is damped by the gap 45, since the cutting inserts are fixed with a slight elastic flexibility in the recesses 10.

The gap 45 allows a certain flexibility of the cutting insert 6 in the recess 10, so that an impact load acting on the cutting insert 6 is damped by a bending or tilting movement about the clamping region between the front end face 41 of the threaded bolt 40 and the bearing surface 12. Thus, at the start of the impact loading, the mechanical load is initially introduced into the clamping region between the front end face 41 and the bearing surface 12 and, via the threaded bolt 40, into the tooth flank 16. Thus the load is distributed by the time it is introduced into the stable centre of the saw-tooth base 5. Only under further stressing of the cutting insert 6 is the latter pressed onto the back mating surface 14, the remaining, reduced load being introduced into the radially outer region of the tooth flank 16.

This two-part design, comprising the saw-tooth base 5 and the cutting insert 6, has a surprisingly high resistance to impact loads, resulting in a long service life, even under intensive saw-tooth loading. It is extremely rare for fragments to break off the teeth or tooth flanks.

Preferably, the cutting insert is formed from highspeed steel, heat-treated steel, sintered carbide, ceramic or the like and/or is coated on its surface - - with a hard material, such as for example sintered carbide, diamond, cubic boron nitride, ceramic, super high-speed steel or the like .

The cutting inserts may be thermally hardened, for example by a heat treatment. Furthermore, the cutting inserts 6 according to the invention can easily be coated at high temperatures, e.g. using a CVD process, and attached to the sawblade body 2. The exchangeability of the cutting inserts 6 allows them to be reprocessed by regrinding and recoating.

A sawblade body 2 can be used for cutting various materials, in which case it is merely necessary to exchange the cutting inserts 6 which are adapted to the particular material which is to be cut. This facilitates storage and reduces the number of different saw blades required.

The two-part design of the saw teeth also reduces the noise, since dry friction occurs between the cutting insert and the saw-tooth base, which friction has the effect of reducing the noise produced.

Further exemplary embodiments of the invention are explained below. These exemplary embodiments have essentially the same structure as the first exemplary embodiment; consequently, identical parts are provided with identical reference numerals.

In the saw blade 1 in accordance with the second exemplary embodiment (Fig. 2a - 2e) , a radially running circular groove 48 is formed centrally on the back mating surface 14 of the recess 10. A guide web 49, which is of corresponding shape to the circular groove 48 and extends in the radial direction, is formed on the back surface 26. When viewed from above, the guide web 49 has side walls 50 which are in the form of arcs of a circle and a flattened end face 51. The guide web 49 lies in an approximately positively-locking manner in the circular groove 48. This engagement between the guide web 49 and the circular groove 48 fixes the axial position of the cutting insert 6 with respect to the saw blade 1 unambiguously. As a result, therefore, the axial position of the cutting insert 6 on the sawblade body 2 is fixed.

The third exemplary embodiment of the saw blade 1 according to the invention (Fig. 3a to 3e) has a cutting insert 6 with a groove 53 which, when viewed from above is, U-shaped and, in particular, rectangular in the region of the back surface 26. The groove 53 is arranged in the transverse centre of the back surface 26 and extends in the radial direction. On the sawtooth base 5, adjacent to the back mating surface 14, the side walls are cut away, so that the cutouts 54 formed as a result produce a guide web 55 which runs in the radial direction and fits in an approximately positively-locking manner into the groove 53. For production engineering reasons, the cutouts 54 extend as far as into the region below the bottom surface 13 of the recess 10. The engagement of the guide web 55 in the groove 53 of the cutting insert 6 fixes the radial position of the latter on the saw blade 1.

A fourth exemplary embodiment of the saw blade 1 according to the invention (Fig. 4a to 4e) , like the third exemplary embodiment, has a guide groove 53 on the back surface 26 and a guide web 55 on the back mating surface 14. When viewed from above, the guide groove 53 and the guide web 55 are in dovetail form, so that an approximately positively-locking engagement of the guide web 55 in the guide groove 53 fixes both the axial position of the cutting insert 6 on the saw blade 1 and fixes the cutting insert 6 in the direction of rotation 8. The cutout 35 intersects two flanks 57 of the dovetail groove 53, which flanks project inwardly into the groove 53, with the result that a curved cut edge 58 (Fig. 4c) is produced.

In a fifth exemplary embodiment, a guide groove 48 which runs in the radial direction and has a triangular cross-section when viewed from above (Fig. 5b) is formed on the back mating surface 14 of the recess 10. On its back surface 26, the cutting insert 6 has a corresponding guide web 49 which, when viewed from above, is of approximately triangular form with two side walls 50 and a flattened end face 51 and fits in a positively-locking manner into the guide groove 48. The engagement of the guide web 49 in the guide groove 48 fixes the axial position of the cutting insert 6 in the saw blade 1.

According to a sixth exemplary embodiment of the saw blade 1 according to the invention, the back mating surface 14 of the recess 10 is approximately in the form of a triangle, when viewed from above, with two side flanks 58 and a flattened end face 59. The back surface 26 of the cutting insert 6 is designed with a corresponding cutout 60, which when viewed from above is approximately in the form of a triangle, with two flanks 61.

The seventh exemplary embodiment of the saw blade 1 according to the invention (Fig. 7a - 7e) has a guide groove 53 with a cross-section which is in the form of a semicircle, when viewed from above, on. the back surface 26 of the cutting insert 6. The guide groove 53 is arranged in the. transverse centre of the back surface 26 and extends in the radial direction. A guide web 55 with a cross-section which is approximately semicircular when viewed from above and a flattened end face 63, in a manner corresponding to the guide groove 53, is formed on the guide mating surface 14 of the recess 10. The engagement of the guide web 55 in the guide groove 53 fixes the axial position of the cutting insert 6 of the saw blade 1.

The eighth exemplary embodiment of the saw blade 1 according to the invention has the same physical form as the third exemplary embodiment; the cutting insert 6 is provided on its back surface 26 with a guide groove 53 which is of rectangular cross-section, is arranged in the transverse centre, in the radial direction, of the back surface 26 and is delimited by two side webs 65. A corresponding guide web 55 is formed on the back mating surface 14 by two cutouts 54. A bore 66 is made in the tooth flank 16, which bore passes through the sawblade body 2 in the axial direction of the saw blade 1 and is arranged with its edge region in the guide web 55. The bore 66 is situated approximately at the level of the bearing surface 12 and serves to accommodate a clamping means, such as for example a rivet, a screw or a clamping pin, by means of which the cutting insert 6 can be clamped against the bearing surface 12. Therefore, recesses 67, which are in the form of an arc of a circle and correspond to the bore 66, may be provided on the webs 65, into which recesses the clamping means engages for the purpose of fixing the radial position. 125519/2 - 14 - PATENT

Claims

1. A saw blade for cutting steel, nonferrous metals or wood and plastics, having a sawblade body on the periphery of which saw teeth are arranged, which project radially outwards and are in each case formed by a saw-tooth base and a cutting insert characterized in that a recess which . is open on each side, with a bearing surface which is leading in the direction of rotation and a trailing back mating surface and a bottom surface is formed in the saw-tooth base and the cutting insert is arranged with a frontal surface which is leading in the direction of rotation bearing against the bearing surface and with a back surface facing towards the back mating surface a clamping device being provided which presses the cutting insert against the bearing surface

2. The saw blade according to Claim 1, characterized in that the clamping device presses the cutting insert against the bottom surface as well.

3. The saw blade according to Claim 1 or 2, characterized in that a damping gap is formed between the back surface and the back mating surface

4. . The saw blade according to one of Claims 1 to 3, characterized in that the saw-tooth base is formed integrally on the sawblade body proj ecting 125519/2 - 15 - radially outwards, and when viewed from the side approximately in the form of a convexly curved hump.

5. , The saw blade according to Claim 4, characterized in that that region of the saw-tooth base which trails the recess forms a tooth flank with a tooth-flank boundary edge which is preferably convexly curved, a threaded bore which extends from the tooth-flank boundary edge and opens into the recess being made in the tooth flank in order to form the clamping device, the threaded bore being inclined radially inwards in the direction of rotation so that a longitudinal centre axis of the bore includes an angle (a) with a perpendicular to the back mating surface which lies, for example, in the range from approximately 10° to 40°.

6. The saw blade according to Claim 5, characterized in that the angle (a) lies in the range from 20° to 30°.

7. The saw blade according to one or more of Claims 1 to 6, characterized in that the recess is designed in the form of a U-shaped groove in a leading half of the: base of the saw blade

8. The saw blade according to one of the preceding claims, characterized in that the bearing surface and the back mating surface on the saw blade are arranged approximately in the radial direction and are perpendicular to a bottom surface the saw-tooth base at the region trailing the back mating surface forming a tooth flank with a convexly curved tooth-flank boundary edge

9. The saw blade according to one of Claims 4 to S, characterized in that the saw-tooth base at the 12 - 16 - region leading the bearing surface being designed so as to project less far outwards in the radial direction than the tooth flank so as to form a chip space with the result that, by way of example, the radial length of the bearing surface is approximately half the size of the radial length of the back mating surface

10. The saw blade according to one of the preceding claims, characterized in that the region leading the bearing surface has a chip-space boundary edge which is curved convexly inwards in the radial direction in the direction of rotation

11. The saw blade according to one of the preceding claims, characterized in that the cutting insert is an approximately cuboid-shaped body with the frontal surface leading in the direction of rotation the trailing back surface two side faces a bottom surface and a land which is arranged opposite to the bottom surface

12. The saw blade according to Claim 11, characterized in that the frontal surface >' is relief-ground in the region of the land and the side faces , the edge between the frontal surface or front surface and the land forming a main cutting edge and the edges between the frontal surface and the side faces forming secondary cutting edges

13. The saw blade according to Claim 11 or 12, characterized in that the cutting insert is inserted in the recess in the saw-tooth base in such a manner that its bottom surface bears against the bottom surface of the recess the main cutting edge projecting radially outwards on the saw-tooth base and on the cutting insert 1 - 17 -

14. The saw blade according to one or mere of Claims 11 to 13, characterized in that a cutout is arranged on the back surface so as to lie opposite a threaded bore in the saw-tooth base the cutout having a planar cutout base and a side wall

15. The saw blade according to Claim. 14, characterized in that the cutout base is arranged approximately perpendicular to the longitudinal centre axis of the threaded bore and the side wall is formed by a semicircular curve and two vertically adjoining flanks

16. The saw blade according to one of the preceding claims, characterized in that a threaded bolt is screwed into a threaded bore which is formed in a region trailing the recess the sawtooth flank ·, as a clamping device for fixing the cutting insert in the recess

17. The saw blade according to Claim 16, characterized in that the threaded bolt has a front and rear end face a recess , for a tool to engage in being formed in the rear end face and the front end face bearing against the cutout base with preloading, so that the threaded bolt presses the cutting insert against the bearing surface in the direction of rotation

18. The saw blade according to one of the preceding claims, characterized in that the cutting insert is formed from high-speed steel, heat- treated steel, sintered carbide, ceramic, and the like.

19. The saw blade according to one of the preceding claims, characterized in that the cutting insert is coated on its surface with a hard material. 1 1 /2 - 18 -

20. The saw blade according to Claim 19, characterized in that the cutting insert is coated with sintered carbide, diamond, cubic boron nitride, ceramic or super high-speed steel.

21. The saw blade according to one of the preceding claims, characterized in that the cutting insert is thermally hardened by a heat treatment.

22. The saw blade according to one of the preceding claims, characterized in that the cutting insert is coated in a CVD process. For the Applicants