DE102009047874B3 - Band saw and saw blade - Google Patents

Abstract

The task of providing a saw blade with which both a high cutting performance, a precise sectional image and a high surface quality can be achieved on the cut surfaces is achieved by the saw blade according to the invention, which has a large number of teeth Z with different geometries, which are regular or irregular Repeat the distances, the different geometries being determined using the following parameters: clearance angle α; Wedge angle β; Rake angle γ; tangential clearance angle α; radial clearance angle α; Angle of attack K; Height of the dog tooth Width of the tooth B, the tooth Z with the greatest height H = H having the largest relief angle α and, in descending order, the tooth Z with the lowest height H = H having the largest relief angle α.

Description

The present invention relates to a saw blade, in particular for band saws with a plurality of teeth, which have different geometries that repeat at regular or irregular intervals.

From the prior art it is known to produce saw blades with a plurality of teeth, which have different geometries.

Out DE 42 00 423 C2 For example, a saw blade having a main body and unrestrained teeth is known which has repetitive cycles of teeth, each cycle having at least one group of teeth having a decreasing tooth to tooth height and increasing width. The teeth are formed symmetrically to a longitudinal center plane through the body. The effective cutting or cutting portions of all teeth are each formed by a kinking cutting edge whose inner portion extends approximately perpendicular to the longitudinal center plane and to which an outwardly inclined to the base phase phase follows. The widest tooth in the tooth group has an angle greater than 90 ° between phase and flank.

When using such saw blades, it has proved to be disadvantageous that, despite good cutting performance, the surface roughness R _{z is} relatively coarse. This is attributed to the susceptibility to soaring of such saw blades.

The object of the present invention is therefore to provide a saw blade with which both a high cutting performance, a precise cutting pattern and at the cut surfaces a high surface quality can be achieved.

This object is achieved by the saw blade according to the invention with the features of claim 1.

Advantageous developments of the present invention are given in the subclaims 2-10.

The saw blade according to the invention has a multiplicity of teeth Z _{1,..., N} with different geometries, which repeat at regular or irregular intervals, the different geometries being determined by the following parameters: clearance angle α; Wedge angle β; Rake angle γ; Tangential clearance angle α _t ; Radial clearance angle α _r ; Angle of attack κ _{1,2,3, ..., N} ; Height of the tooth H _value and width of the tooth B _value , where the tooth Z ₁ with the highest height H _value = H _max the largest clearance angle α _max and in descending order the tooth Z _{1 + X} with the lowest height H _value = H _min having the largest clearance angle α _min .

According to the invention, the tooth geometry is repeated at regular or at irregular intervals, so that a negative Aufschwingverhalten is avoided. The present invention develops its advantages particularly in band saws. The present invention can also be used in circular saws or other saw blades.

Since band saws consist of a closed band, the numbering of the teeth required for this invention can begin with any tooth with Z ₁ . The continuous numbering of the teeth is done with Z ₁ , Z ₂ , ... Z _N in the cutting direction. The tooth geometry is repeated according to the invention after every third, fourth or Nth tooth. But it is also possible that the tooth geometry is repeated at irregular intervals.

In a regular repetition of the number geometry, it may be advantageous to make a repetition pattern, for example, the following manner: N = 3, ie after three teeth, the tooth geometry is repeated; N = 4, ie after four teeth, the tooth geometry is repeated, etc. With repetition of the tooth geometry, the parameter modifications for the width B _value , height H _value , rake angle γ, and clearance angle α, α _t , α _{r will} repeat according to the invention.

In an irregular repetition of the tooth geometry, it may be advantageous to make a repetition pattern, for example, the following manner: N = 3, 4, 5 or 6, ie, for example (3, 4, 3, ...); (3, 5, 3, ...); (4, 5, 4, 4, 5, ...); (3, 5, 6, 5, 3, ...), the numbers representing the repetition of the parameter modifications for the width B _value , height H _value , rake angle γ, and clearance angle α, α _t , α _r .

Advantageously, the tooth Z ₁ with the greatest height H _{max is formed} with the narrowest width B _value = B _min , and in descending order the tooth Z _{1 + x} with the lowest height H _{min has} the greatest width B _value = B _max .

Advantageously, the rake angle γ ₁ at the tooth Z ₁ with the highest height H _value = H _{max is} the largest and in descending order the angle γ _{1 + x} at the tooth Z _{1 + x} with the lowest height H _value = H _min the smallest.

In a preferred embodiment of the saw blade according to the invention, the tangential and radial clearance angle α _r , α _{t is} equal to zero for every second, third, fourth or fifth tooth.

In a preferred embodiment of the present invention, every second tooth with the lowest height H _value = H _min and a maximum width B _value = B _{max has} a tangential and radial clearance angle α _r , α _t equal to zero.

Advantageously, the saw blade according to the invention is designed so that the angle of attack κ _{1,2,3, ..., N} is different for adjacent teeth. This angle of attack may have a difference between 1 ° and 25 ° in adjacent teeth, advantageously between 3 ° and 15 °, or in a preferred embodiment, the difference in angle of attack κ _{1,2,3, ..., N} of adjacent teeth at least between 5 ° and 7 °.

In a preferred embodiment of the present invention, the angle of attack K is formed at three consecutive teeth Z _i , Z _{i + 1} and Z _{i + 2} according to the following values: K _i = 22 °, K _{i + 1} = 35 °, K _{i + 2} = 45 °.

The following advantages are achieved with the present saw blade according to the invention.

Due to the different height and width of successive cutting teeth, the cutting performance distributed over the plurality of teeth, that over the prior art very uniform and smooth cutting profile is achieved. This prevents cutting breakouts and cutting edge breakouts.

Furthermore, by the variation of the angle of attack κ as well as by the modification according to the invention the tangential clearance angle α _t and α _r a higher surface quality, in particular the surface roughness, is achieved compared to the prior art.

The inventive choice of parameters has the advantage that the smoothness compared to conventional saw blades is higher, so that the noise level is much lower. While in conventional saw blades, the noise level can be up to 120 dB, this is much lower in the inventive device.

According to the parameters height and width of the tooth are so matched to the tangential clearance angle α _t and α _r that the cut surfaces is not affected by vibrations of the saw blade in their surface quality by the smoothness achieved during sawing, but the cutting channel on both sides a high Surface quality and has a low ripple.

While the minimization of waviness is essentially due to the height and width of the cutting teeth, the roughness depth R _z is essentially influenced by the modification of the tangential clearance angles α _t and α _r . The tuning according to the invention of these parameter groups, in particular the regular reduction of the tangential clearance angles α _t and α _r to zero in the case of the saw blade according to the invention, leads to a surface quality which could hitherto not be achieved with saw blades of the prior art.

Four preferred embodiments of the present invention will be explained in more detail with reference to the following figures, wherein the embodiment 1 and its parameters are explained in detail in the following table.

For the embodiments 2, 3 and 4, the parameter information (height, phase width and width) of embodiment 1 are to be adjusted by means of a rule of three. Example: 1.6 mm strip thickness / 2.4 mm max. Phase width corresponds to 0.9 mm strip thickness / 1.7 mm max. Phase width.

The preferred embodiment 1 is carried out on a saw blade with a belt thickness of 1.6 mm and a group of 3 teeth 1, 2 and 3. Tooth 1 Tooth 2 Tooth 3 Clearance angle α 20 ° 21 ° 22 ° Rake angle γ 11 ° 10 ° 9 ° Angle of attack κ 22 ° 35 ° 45 ° phase width 0.4 mm 1.5 mm 2.4 mm Tooth height H H _max = H ₁ H ₁ = H ₂ + 0.1 mm H _min <H ₂ <H _max H ₂ = H _min + 0.1 mm H _min = H ₃ reference height: H _min Tooth width B B _min B _max > B ₂ > B _min B _max

The preferred embodiment 2 is carried out on a saw blade having a band thickness of 0.9 mm and a group of 3 teeth 1, 2 and 3.

The preferred embodiment 3 is carried out on a saw blade with a strip thickness of 1.1 mm and a group of 3 teeth 1, 2 and 3.

The preferred embodiment 4 is performed on a saw blade with a belt thickness of 1.3 mm and a 3-group of teeth 1, 2 and 3.

Show it:

1 a frontal detail of three cutting teeth Z ₁ , Z ₂ , Z _{3 of} the present invention of the embodiment 1;

2 a side view of the teeth Z ₁ , Z ₂ , Z _{3 of} the present invention of the embodiment 1;

3 a plan view of the teeth Z ₁ , Z ₂ , Z _{3 of} the present invention of the embodiment 1;

4 a frontal view of three cutting teeth Z ₁ , Z ₂ , Z _{3 of} the present invention of the embodiment 1;

5 a schematic representation of three cutting teeth Z ₁ , Z ₂ , Z ₃ and their clamping surfaces and the chip cross sections of the individual teeth at a feed rate f _z = 0.01 mm of the present invention of the embodiment 1;

6 a schematic representation of three cutting teeth Z ₁ , Z ₂ , Z ₃ and the clamping surfaces of the present invention of the embodiment 2;

7 a schematic representation of three cutting teeth Z ₁ , Z ₂ , Z ₃ and the clamping surfaces of the present invention of the embodiment 3;

8th a schematic representation of three cutting teeth Z ₁ , Z ₂ , Z ₃ and the clamping surfaces of the present invention of the embodiment 4;

9 a schematic top and side view of six teeth with a tooth 3 * with radial clearance angle α _r = 0.

The dimensions for the embodiment 1 are shown in the drawings 1 to 4 directly.

The saw blade according to the invention with the features of embodiment 1 was subjected to a load test in which the cutting speed was 70 m / min and the feed at 25 mm / min. For experimental purposes, the feed rate was increased up to 100 mm / min, although no outbreaks occurred. In this stress test, a cylinder profile of 250 mm diameter made of 1.4571 austenitic steel material was used. The roughness R _z was between 25 and 40 microns. Compared with conventional saw blades, an improvement in the surface quality could be achieved with the saw blade according to the invention; the wear mark width was 20% less than with conventional saw blades.

In the 5 to 8th the rake surfaces of the saw blade variants according to the invention are shown. In order to prevent or reduce the damaging Aufschwingverhaltens, which results in both a higher noise emission and a poorer surface quality, the clamping surfaces of the teeth are dimensioned according to the invention so that successive teeth have no same rake surfaces. According to 5 For the embodiment 1 this means that tooth 1 has a rake face of 0.92 mm ² , tooth 2 has a rake face of 0.88 mm ² and tooth 3 has a rake face of 0.60 mm ² . The different rake surfaces of the embodiments 2, 3 and 4 are the 6 . 7 and 8th refer to.

According to the invention, the largest tooth surface and thus the descending shorter teeth, a decreasing smaller rake face is removed in the cutting process of the highest tooth.

Claims (11)

Saw blade with a plurality of teeth Z _{1, ..., N} , which have different geometries that repeat at regular or irregular intervals, the different geometries are determined by the following parameters: - clearance angle α - wedge angle β - angle of attack κ _{1 , 2,3, ..., N} - height of the tooth H _value characterized in that the tooth Z ₁ with the highest height H _value = H _max the largest clearance angle α _max and in descending order of the tooth Z _{1 + X} with the lowest height H _value = H _{min has} the smallest clearance angle α _min . Saw blade according to claim 1, wherein the tooth Z ₁ with the greatest height H _{max has} the narrowest width B _value = B _min and in descending order the tooth Z _{1 + X} with the lowest height H _{min has} the greatest width B _value = B _max . Saw blade according to one of claims 1 or 2, wherein the rake angle γ in the tooth Z ₁ with the highest height H _value = H _{max is} largest and in descending order the rake angle γ at the tooth Z _{1 + X} with the lowest height H _value = H _{min is} the smallest. Saw blade according to one of the preceding claims, wherein the tangential clearance angle α _{t is} equal to zero for every second tooth Z ₃ . Saw blade according to one of the preceding claims, wherein every second tooth with the lowest height H _value = H _min and a maximum width B _value = B _{max has} a tangential and radial clearance angle α _r = 0, α _t = 0. Saw blade according to one of the preceding claims, wherein the radial clearance angle α _r and tangential clearance angle α _t at each fourth or fifth tooth Z _{I + 4} or tooth Z _{I + 5 is} equal to zero. Saw blade according to one of the preceding claims, wherein the angle of attack κ _{1,2,3, ..., N of} adjacent teeth Z is different. Saw blade according to claim 7, wherein the difference of the angle of attack κ _{1,2,3, ..., N of} adjacent teeth between 25 ° and 1 °. Saw blade according to claim 7, wherein the difference of the angle of attack κ _{1,2,3, ..., N of} adjacent teeth between 15 ° and 3 °. Saw blade according to claim 7, wherein the difference of the angle of attack κ _{1,2,3, ..., N of} adjacent teeth is at least between 7 ° and 5 °. Saw blade according to one of claims 1 to 7, wherein the angle of attack κ in three successive teeth Z _I , Z _{I + 1} , and Z _{I + 2 has} the following value: κ _I = 22 ° κ _{I + 1} = 35 ° κ _{I + 2} = 45 °.

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