SAWING TOOL HAVING A PLURALITY OF DIAMOND SAW BLADES FOR FORMING A SURFACE STRUCTURE ON A ROAD SURFACE

Abstract

The invention relates to a sawing tool (7) for forming a surface structure on a road surface, at least having: a shaft (6) and a plurality of diamond saw blades (1), wherein each diamond saw blade (1) has a disc-shaped core with a hole for placing on the shaft (6), and a segment (3) which is arranged on an outer circumference of the core, wherein the diamond saw blades (1) are arranged on the shaft (6) by way of the disc-shaped core. The invention provides for the segments (3) of adjacent diamond saw blades (1) to be in surface contact on a longitudinal side (13), wherein each segment (3) is formed from at least two layers (8.i; i=1 . . . 6) that adjoin one another in the axial direction and each extend in the radial and axial direction, wherein layers (8.i; i=1 . . . 6) of the segment that axially adjoin one another each have different wear resistances (VF, VF.sub.1, VF.sub.2) and the wear resistance (VF, VF.sub.1, VF.sub.2) of the layers (8.i; i=1 . . . 6) in the axial direction alternates over the entire segment (3), wherein a furrow is able to be formed in each case by two layers (8.i; i=1 . . . 6) that axially adjoin one another, in order to set a grip and a level of noise of the road surface, and layers (8.i; i=1 . . . 6) that axially adjoin one another of adjacent segments (3) have different wear resistances (VF, VF.sub.1, VF.sub.2) in order to form an alternating layer structure over the entire sawing tool (7).

Claims

1. Sawing tool (7) for forming a surface structure (11, 14) on a road surface (10), having at least: a shaft (6) and a plurality of diamond saw blades (1), wherein each diamond saw blade (1) has a disc-like core (2) having a hole (5) for placing on the shaft (6), and a segment (3) which is arranged on an outer periphery of the core (2), wherein the diamond saw blades (1) are arranged with the disc-like core (2) on the shaft (6), characterised in that the segments (3) of adjacent diamond saw blades (1) touch each other in a planar manner at a longitudinal side (13), wherein each segment (3) is formed from at least two layers (8.i; i=1 . . . 6) which adjoin each other in an axial direction (X) and which extend in each case in a radial and axial direction (X), wherein axially adjacent layers (8.i; i=1 . . . 6) of the segment (3) each have different levels of wear resistance (VF, VF.sub.1, VF.sub.2) and the wear resistance (VF, VF.sub.1, VF.sub.2) of the layers (8.i; i=1 . . . 6) alternates in an axial direction (X) over the entire segment (3), wherein by means of two axially adjacent layers (8.i; i=1 . . . 6) a groove (11) can be formed in order to adjust a skid resistance property and a noise level of the road surface (10), and layers (8.i; i=1 . . . 6), which are adjacent in an axial direction (X), of adjacent segments (3) have different levels of wear resistance (VF, VF.sub.1, VF.sub.2) in order to form an alternating layer construction over the entire sawing tool (7).

2. Sawing tool (7) according to claim 1, characterised in that a segment (3) has an even number (n) of at least four or an odd number (n) of at least five layers (8.i; i=1 . . . 6), wherein a groove (11) can be formed in each case by means of two axially adjacent layers (8.i; i=1 . . . 6).

3. Sawing tool (7) according to claim 1 or 2, characterised in that each layer (8.i; i=1 . . . 6) has diamonds and the wear resistance (VF, VF.sub.1, VF.sub.2) of the layers (8.i; i=1 . . . 6) is dependent on the concentration and/or the size of the diamonds.

4. Sawing tool (7) according to claim 3, characterised in that the wear resistance (VF, VF.sub.1, VF.sub.2) of the layers (8.i; i=1 . . . 6) is dependent on a material composition of the layers (8.i; i=1 . . . 6), wherein the material composition contains a hardened metal material, for example, of tungsten carbide, steel and/or copper for chemically and mechanically binding the diamonds.

5. Sawing tool (7) according to any one of the preceding claims, characterised in that the multi-layer segment (3) is sintered.

6. Sawing tool (7) according to any one of the preceding claims, characterised in that the segment (3) has a segment width (B2) of from 3 mm to 20 mm, for example, 6 mm.

7. Sawing tool (7) according to any one of the preceding claims, characterised in that the layers (8.i; i=1 . . . 6) of a segment (3) have a segment width (B1) of from 1 mm to 3 mm, preferably 1 mm.

8. Sawing tool (7) according to any one of the preceding claims, characterised in that the layers (8.i; i=1 . . . 6) in the segment (3) are rounded at the outer periphery thereof in a surface region (9.1, 9.2) in an axial direction (X), wherein the rounding of axially adjacent layers (8.i; i=1 . . . 6) alternates over the entire segment (3) so that layers (8.i; i=1, 3, 5) having a first wear resistance (VF.sub.1) are, for example, rounded in a substantially concave manner and layers (8.i; i=2, 4, 6) having a second wear resistance (VF.sub.2) are, for example, substantially convex in order to form an undulating segment surface (9) and an undulating texturing on the road surface (10).

9. Sawing tool (7) according to any one of the preceding claims, characterised in that the cores (2) of adjacent diamond saw blades (1) are spaced apart from each other by means of a spacer (12).

10. Sawing tool (7) according to any one of the preceding claims, characterised in that a groove depth (T) of a groove (11) which is formed by a diamond saw blade (1) on a road surface (10) is determined by the difference of a diameter of the layers (8.i; i=1 . . . 6) and a groove width (B4) of the groove (11) is determined by a layer width (B1) of the layers (8.i; i=1 . . . 6).

11. Sawing tool (7) according to any one of the preceding claims, characterised in that a segment (3) is pressed in layers with different levels of wear resistance (VF, VF.sub.1, VF.sub.2).

12. Machine (15), having at least: a retention member (16) which can be lowered on a road surface (10) and which retains a sawing tool (7) according to any one of the preceding claims and which is constructed to rotate the shaft (6) of the lowered sawing tool (7) in such a manner that a surface structure (11, 14) can be formed on a road surface (10).

13. Method for forming a surface structure (11, 14) on a road surface (10) with a sawing tool (7) according to any one of claims 1 to 11, wherein the sawing tool (7) is lowered onto the road surface (10) and pressed onto it, is rotated at a peripheral speed of from 35 to 55 m/s and is moved at a speed of from 3 m per minute to 10 m per minute over the road surface (10) in order to form the surface structure (11, 14), wherein the layers (8.i; i=1 . . . 6) depending on the wear resistance (VF, VF.sub.1, VF.sub.2) are rounded at the outer periphery thereof in a surface region (9.1, 9.2), wherein layers (8.i; i=1, 3, 5) having a first wear resistance (VF.sub.1) are rounded in a substantially concave manner and layers (8.i; i=2, 4, 6) having a second wear resistance (VF.sub.2) are rounded in a substantially convex manner so that an undulating segment surface (9) and an undulating surface structure (11, 14) are formed on the road surface (10).

Description

[0043] Subsequently, the invention is further illustrated by means of the drawings on the example of an embodiment. It is shown in:

[0044] FIG. 1 a diamond saw blade in an elevation;

[0045] FIG. 2 a detail of the diamond saw blade according to FIG. 1 in a sectional view;

[0046] FIG. 2a a used diamond saw blade according to FIG. 2 over a structured road surface;

[0047] FIG. 3 a sawing tool with several used diamond saw blades in a sectional view; and

[0048] FIG. 4 a machine having a sawing tool according to FIG. 3.

[0049] According to FIG. 1 a diamond saw blade 1 is provided comprising a disc-like core 2 and, at its outer periphery 2.1, a circumferential segment 3. The segment 3 is subdivided by radial cuts 4 into several segment regions 3.1, 3.2, 3.3, etc. The segment 3 or the segment regions 3.1, 3.2, 3.3 are affixed to the core 2 preferably by means of sintering, soldering, gluing or welding. In the centre of the core 2 a concentric hole 5 is provided by means of which the diamond saw blade 1 can be placed onto a shaft 6 of a sawing tool 7 (s. FIG. 3).

[0050] According to this embodiment example, the segment 3 is formed from six layers 8.i, where i=1 to 6, which adjoin each other in an axial direction X in a planar manner, as shown in FIG. 2. In the axial direction X each layer 8.i has a layer width B1 of ca. 1 mm so that the segment 3 has a total segment width B2 of 6 mm. A core width B3 is ca. 3 mm, i.e. it is smaller than segment width B2. An outer segment surface 9 is planar at first, with the unused diamond saw blade 1, according to FIG. 2. I.e. an outer diameter D1 (see FIG. 1) of the segment 3 extends essentially consistently across the entire segment 3.

[0051] The individual layers 8.i have differing wear resistances VF, whereby the wear resistance within the segment 3 alternates. I.e. a first layer 8.1 has a low wear resistance VF.sub.1, the second layer 8.2 a high wear resistance VF.sub.2. This is followed by a third layer 8.3 with the lower wear resistance VF.sub.1 and a fourth layer 8.4 with the high wear resistance VF.sub.2, etc. (see FIG. 2a).

[0052] The wear resistance VF is determined by the material composition of the respective layers 8.i. Hereby, a layer 8.i is manufactured from a powder mixture made of, in particular, diamonds and a metal powder by means of a hardening process, e.g. sintering. Hereby, a concentration or a size of the diamonds and/or the material composition of the metal powder, e.g. tungsten carbide, iron and/or copper, defines the hardness and, therewith, the wear resistance VF of the layer 8.i.

[0053] Owing to the different wear resistances VF each layer 8.i has an a different interaction with the material of a road surface 10 to be structured using the diamond saw blade 1. In case of a hard material of the road surface 10 a layer 8.i with high wear resistance VF.sub.2 takes more time to wear than with a layer 8.i having a low wear resistance VF.sub.1.

[0054] This leads to a development of the outer segment surface 9, which is shown FIG. 2a, showing a segment 3 in its used state. Hereby, the outer segment surface 9 is waved whereby a first surface area 9.1 of the first, third and fifth layer 8.1, 8.3, 8.5 is approximately concave and a second surface area 9.2 of the second. Fourth and sixth layer 8.2, 8.4, 8.6 approximately convex. This results in a wavy, smooth transition between the layers 8.i, this being merely an idealised progression of the segment surface 9, which may vary slightly as a result of impurities in the road surface 10 or a inhomogeneous material composition of the layers 8.i.

[0055] The concave or convex bulging my essentially be achieved by virtue of the arrangement of the individual layers 8.i in relation to each other, i.e. by having the individual die layers 8.i adjoin each other in an axial direction X. This leads to a layer 8.i with high wear resistance VF.sub.2 first wearing at the edges and a layer 8.i with low wear resistance VF.sub.1 first in the centre so that the afore-mentioned bulges appear.

[0056] When the diamond saw blade 1 is made to rotate and pressed against the road surface 10, then the top of the road surface 10 is removed in the areas where a layer 8.i with high wear resistance VF.sub.2 acts, as shown in FIG. 2a. In the areas, where a layer 8.i with low wear resistance VF.sub.1 is applied, the top is merely slightly rounded so that several grooves 11 are created with groove widths B4 corresponding approximately to the layer width B1. The grooves 11 have a groove spacing B5 also of approximately the layer width B1.

[0057] Thus, the segment surface 9 constitutes the negative of the desired texturing in the road surface 10. Thus, the wavy segment surface 9 is also transferred onto the road surface 10. This leads to a bridge 14 lying between the grooves 11 also being rounded so that e.g. ice enclosed in the groove 11, when expanding, cannot push away the bridge 14 and break it off.

[0058] In order to provide a road surface 10 with grooves 11 over a larger area, pursuant to FIG. 3, a sawing tool 7 is provided comprising a shaft 6 and several diamond saw blades 1. The diamond saw blades 1 are place on the shaft 6 and affixed thereto such that they cannot turn in relation thereto. Between the diamond saw blades 1 each a distance piece 12 (Spacer) running around the perimeter of the shaft 6 is provided which holds the diamond saw blades 1 at a distance A in relation to each other. Hereby, the distance A is chosen such that segments 3 of adjacent diamond saw blades 1 touch each other whereby longitudinal sides 13 of adjacent segments 3 touch each other in a planar manner.

[0059] Hereby, the layer construction of the segments 3 is chosen such that the left outer layer 8.1 of each segment 3 is a layer with low wear resistance VF.sub.1 and the right outer layer 8.6 of each segment 3 a layer with high wear resistance VF.sub.2. When such segments 3 are placed next to each other, the right outer layer 8.6 of one segment 3 touches the left outer layer 8.1 of the right side adjacent segment 3 leading to the alternating layer construction of the segment 3 being continued across the entire sawing tool 7.

[0060] Hereby, at a length of the sawing tool 7 of e.g. 0.6 m and a layer width B1 of 1 mm ca. 300 grooves 11 can be structured next to each other into the road surface 10 whereby a groove width B4 of 1 mm and a groove spacing B5 of ca. 1 mm can be attained.

[0061] Hereby, the layer width B1, the segment width B2 as well as the spacing A can be adapted at will in order to attain other groove widths B4 that may be required in terms of noise level, skid resistance property and aquaplaning properties. Moreover, for adapting a groove depth T the material of the layers 8.i can be chosen correspondingly so that this ensues, depending on the depth T desired, after a certain time.

[0062] In order to be able to press the sawing tool 7 onto the road surface 10, according to FIG. 4, a machine 15 is provided, e.g. a floor cutter, with a holder 16 holding the sawing tool 7 in a rotatable manner whereby the sawing tool 7 can be rotated at a peripheral velocity of e.g. 45 m/s. The holder 16 can be made to approach the road surface 10 so that the segments 3 on the diamond saw blades 1 can interact with the top of the road surface 10 whereby this is removed. Depending on the driving power of the machine 15 grooves 11 can be cut into the road surface 10 at a speed of ca. 3 m to 10 m per minute.