LU80791A1 - SAW BLADE - Google Patents

Description

. 1 1 i; "] i | i>: i the object of this invention is a rotary saw blade, v '| I; ij comprising a toothing intended for cutting metal profiles, i; j, iiiotiously blooms, billets, rounds, beams in steel at the outlet; ii j rolling mill trains.

:! 5! These circular saws are mounted on sawing machines i i! Fitted in particular to rolling mill trains in the metal industry: j j • jIgique, and they cut rounds, squares, flat irons, "·! · J; merchant laminates etc ..., the doupe being performed hot between 600 and 1200 degrees C, or cold between 0 and 600 ° C. I! . ^ ^! • j 0; ! 'The known saws used until now in the metallurgical industry, have teeth of very variable profile:

: * I

s: some teeth have teeth whose sides have the same inclination

• f I

jIson on either side of the diameter passing through the tip of the tooth, i! While in other teeth, the sides of each tooth have a different inclination on the diameter of the saw passing through it; Point of tooth. In other known teeth, the teeth have -; more complex profiles, asymmetrical with respect to the tip of the i; teeth.

i! the circular saw blades are made of t - 20 ispecial steels, and generally driven at a speed of the order of 50 to! -. ; ,. -] 120 meters per second approximately. These blades have various disadvantages; faults and defects, including the following.

\ {i i During their work, the teeth become dull, get tired and generate stresses and vibrations which are localized at the bottom of their teeth, and cause the appearance of cracks. These | - cracks called "fatigue", are directed and oriented in the direction of the cut.

_i j filings formed during cutting often manage to cover the hollows separating the teeth, and to plug them, the 30 parts of the blade covered with filings heat by friction and cause other cracks, the material torn off by the blade melts and sticks to the teeth, causing an extremely annoying sizing of these.

the object of the invention is to remedy these drawbacks, by producing a saw blade in which in particular the shavings or filings formed during cutting are reduced and can be

LjO

/ ...

/ »I r ....." - * ~., Γτ— ”7 ~ *" * ™ ~ *; I "completely clear the notches arranged between the teeth, which * i: prevents the sticking of the chips on the teeth. For this purpose, <conform-; i! ; i - even with the invention, each tooth of the toothing comprises two points separated by a hollow, and two consecutive teeth are separated! * '5d | by a recess of depth greater than that of the hollow between! ί two points of the same tooth.

: the subdivision of each tooth into two points reduces practical -;: ment of half the size of the chips produced, which allows them to; '' come out completely from the notch or deeper recess mena-j. i 1 10 ge between two consecutive teeth, and avoids sticking of the shavings on. ! : denture.

'T According to an embodiment of the saw blade concerned':. by the invention, the height above the adjacent hollow of the point j | of each tooth which comes first in contact with the profile to be cut-j

. i | - I

’15; Per, given the direction of rotation of the saw, is slightly lower than | Irieure to the height above the said hollow of the second point; this tooth, this toothing being particularly suitable for "" sawing

; * I

round steel / and the hollow between the two points of each tooth j sharp curved. ’'J20i Each tooth is thus asymmetrical, the front point having a j' height slightly lower than that of the rear point of the ', mime tooth. - [j Such teeth are suitable for sawing ferrous metals, j and its cutting strength, or cutting time is considerably longer than that of known saw blades. .This makes it possible to decrease to a very large extent the frequency of blade changes for "I sharpening, and consequently very significantly increases the productivity of the rolling mill train.

Other features and advantages of the invention will become apparent from the following description.

• In the accompanying drawings, given by way of nonlimiting examples, several embodiments of the saw blade according to the invention have been shown.

- Figure 1 is an elevational view with parts cut away from ur 3E first embodiment of the saw blade according to the invention, intended for cutting ferrous metals.

NOT

J

t l311 •! ! - Figure 2 is an elevational view similar to the figure. " j; 1, showing a second embodiment of the saw blade.

; i! , I I. 'i; - Figure 3 illustrates a third, embodiment of *! d 5 d! the saw blade, intended for sawing non-ferrous metal profiles.

I i | ; - Figure 4 is an elevational view similar to the preceding figures,! showing a fourth embodiment of the blade i | i j saw according to the invention, intended in particular for cutting ‘! round steel. _ j; 10: ‘- Figure 5 is a partial perspective view of a silk,! : circular can be equipped with a blade according to the invention, and installed in a rolling mill train M the rotary saw blade covered by the invention, comprises

i i

i | toothing intended for cutting metal profiles, in particular I; 15;! Blooms, "billets, rounds, beams at the exit of lamins trains | ^ i blacks in the metallurgical industry.

. In the embodiment shown in FIG. 1, each tooth 1 of the teeth of the blade comprises according to the invention ^: "

| ; two points 2 separated by a hollow 3, and two consecutive teeth 1 J

! i · i 20 are separated by a recess 4 whose depth H is greater! .. ’. 'j to that h of the hollow 3 between two points 2 of the same tooth 1. the *! hollows 3 are curved and the heights h of the teeth 2 above the bottom of the adjacent trough 3 which separate them are equal.

. i i This type of profile for the teeth of the saw blade is 25 J particularly suitable for hot sawing of steel beams j In the steel industry.

1,: the embodiment shown in Figure 2 differs from i! ! •; that of FIG. 1 by the fact that the height h1 above the I i i I l! : adjacent trough 3 of the tip of each tooth 2a which arrives the first I! 30 die in contact with the profile to be cut, taking into account the direction of rotation i of the saw, is slightly less than the height h2 above said hollow 3 of the second tip 2b of this tooth. This . toothing in which each tooth 5 is thus asymmetrical, while the teeth 1 in FIG. 1 are symmetrical, is particularly suitable for hot sawing large round steel bars.

the difference h2 - h1 can vary from a few tenths of a millimeter to several millimeters. ''

,. CO

j *. I; the form of execution represented in figure 3 is more gone, - '! especially intended for cutting non-ferrous metals such as (> I 1 * aluminum. In this embodiment, the outer flanks 6 i! · i, ^ I 'of the two points 7 of the same tooth 8, adjoining at the two recesses 9!? 5 J ^ arranged on each side of said tooth 8, are rectilinear and oriented (! jin practically radial directions, the angle A formed between the i · i • j ideux inner rectilinear sides 11 of the tips 7 being additionally— '' tally less than 90 °.

j | · The internal sides 11 are connected by a curved bottom ij - 10;: 12 whose radius of curvature can vary, the external sides 6: ï:: | of two neighboring teeth 8 are also connected by a concave area '18 whose radius of curvature K may vary. XI is the same *:; j | For the distances between two points 7 of the same tooth, and between i; two points 7 separated by a recess 9, as well as for the height i! i 15; points 7 above the adjacent curved bottom 12.

I · j In the embodiment of the saw blade shown in:. Figure 4, the tips 15 of the same tooth have a top pull above. from the bottom of the curved hollow 14 which separates them, less than the height; ih of the teeth 1 of the embodiment shown in FIG. 1. Likewise, the depth or height H1 of the recesses 15 between two points 15 j belonging to two different teeth, is less than the height H. 'j of the embodiment of Figure 1.

! ! | This more flat toothing is suitable for cutting metals | ferrous in general.

i 25 In the three embodiments of FIGS. 1, 2 and 4 »i | intended for sawing ferrous metals, external sides, such as j | j jque 16 (figure i) of the two points 2 of a tooth, adjoining the recesses 4 arranged on each side of said tooth 1, are inclined i on the spokes (not shown) of the saw passing through the vertices i 30 points 2, so as to form recesses 4 with straight walls' converging, while the inner flanks '17 between two points 2 of the same tooth are curved.

On the other hand, in the embodiment of FIG. 3 provided for non-ferrous metals, the curvatures of the hollows between two 55 points of the same tooth, and between two points belonging to two

J

15 1! [‘[Consecutive teeth, are limited to the bottoms of the hollows separating these 1 I ·! 1 ·. 'jjdents, namely at the bottom 12 between two points 7 of the same tooth, and | i. ; lau bottom 18 of a recess 9 separating two points 7 belonging to; Idous neighboring teeth.

! ! 5 d! These saw blades can be mounted on a machine such as: [that shown schematically in Figure 5 · l! i.

I \\ On this one, we see a profile 19, for example in steel i J; ; r; at the exit of a rolling mill, moving on transverse rollers I; '21-opposite a blade 22 of a circular saw 23- The profile or ί £ 10.bar 19, driven on the path bearing constituted by the rollers i, is held laterally by bar pressers 24! during its cutting into sections by the blade 22.

. . 1 ·. A numerical example I I <1 i '. Will be given below by way of indication.

15: Numerical example i • i. I i! I The teeth of Figure 1, particularly intended for i! , steel beams ', can be done in this way, i'

; T

: next: j j. - not p: 28. mm 120 - angle between the outer flanks 16 of a tooth: 60 °.

j ’- distance.between the vertices of the two points 2 of the same’ j tooth 1: 9 mm · - height H of the recesses 4: 12 mm • I - radius of curvature of the bottom of a recess 4:10 mm! 25 - angle B between two external sides 16 delimiting a recess 4: 60 degrees.

'i l i The diameter of the blade provided with this toothing is 1830 mm, I i 1 [its thickness of 11 mm, this blade comprising 200 teeth or 400:; f ‘spikes 2.

30 It was possible to carry out sawing operations on rounds * and steel beams for eight consecutive hours before changing the blade for sharpening, when this had to be done after only two hours of service for a blade provided with a known toothing · 35 The mechanical resistance of the blade according to the invention is therefore considerably increased, since the cutting resistance of this i * r. CÔ * blade is four times greater than that of the anterior blades. For . ‘. the service life of eight consecutive hours, a power consumption corresponding to approximately 0.6 to 0.7 of the power necessary for a known saw is observed during the first four hours, 5. the power consumed during the following four hours being approximately 0.8 to 0.9 of the power required for an anterior blade.

Meanwhile, a conventional blade makes only 30 to 40 cuts in large rounds, while the blade according to the invention can perform 120 cuts before sharpening, the cutting capacity of the blade according to the invention is therefore increased in a considerable proportion.

: t the second test carried out for the flow of the beams for,. * 24 hours, made it possible to make 1200 cuts while the blades! known can only last a maximum of eight hours, during which approximately 300 cuts are made.

Furthermore, with this blade used for sawing beams, it can be seen that during the first twelve hours of work, only 50 ^ of the power necessary for the execution of this cutting work with a conventional blade has been consumed; while

'*' I

20 the following twelve hours, before disassembly, the electrical power consumed was approximately 3/4 of that consumed by a conventional "saw *!"

i i

; ‘In general, the technical advantages of the various; possible embodiments of the saw blade provided by the in-i i 25‘Ivention are the following: i: The splitting of each tooth into two points separated by. a hollow ensures better penetration of the teeth into the material! as hot. As already mentioned above, the volume of the chips :: is reduced substantially by half thanks to the attack of the material 30 by two points instead of only one for each tooth, which avoids • · »i, | gluing the shavings to the teeth, laterally and in the i! · Bottom of the notches. This largely explains the fact that the cutting resistance is 4 to 5 times greater than that of the known blades.

'35 · the fact of being able to use the same blade for a period i: i! much longer between two sharpenings, avoid the obligation! '1'! ! - _________________________

Id1 stop the rolling mill train at each saw change, and

»I

significantly increases its productivity.

•; Furthermore, the cut made is clean and without burr of the i i; jproduct cut and blade.

! ï i5 j Because penetration into the material is easier, it! : The electrical energy required is lower, as mentioned i! : i. above. ' i, the teeth do not crack between two teeth, contrary to what is observed on the usual saw blades.

i i 10; the invention is not limited to the various embodiments described: and may include alternative embodiments. Thus, the relative dimensions of the points, of the hollows which separate them and of the notches or recesses between the teeth can vary within one! large measure depending on the type of application intended for dentistry.

I · ':: As can be seen from the above description, the profile i; -; of it varies widely depending on whether it is intended for cutting. ferrous or non-ferrous metals.

* i, i! · I - i. .

i i Æ i - i tj

i! i i

vs ! i i • i! ; i i k Λ

Claims (3)

3. Saw blade according to claim 1, intended in particular! j to sawing of steel beams, characterized in that the heights of the two points of each tooth above the bottom of the recess which separates them are equal, the abovementioned recess being curved. 4. Saw blade according to claim 1, intended for cutting j it f ^ i j j non-ferrous metals such as aluminum, characterized in that j! i i. j I I; the outer flanks of the two points of the same tooth, attj; ! ; nants to the two recesses arranged on each side of said tooth, '*! t j i 25. are rectilinear and oriented in directions practically j. | i radial, the angle formed between the two rectilinear inner flanks of the tips of the tooth being complementarily less than 90 degrees. 5. Saw blade according to one of claims 1 to 3, characterized 150 in that the outer flanks of the two points of a tooth, adjoining the recesses arranged on each side of said tooth, j are inclined on the spokes of the saw passing through the apices of the points so as to form recesses with converging rectilinear walls, while the internal flanks between two points of said tooth are curved.