CZ303739B6 - Circular saw blade teeth - Google Patents

Abstract

In the present invention, there is disclosed a circular saw blade intended particularly for severing solid or hollow metal and composite sections. The cutting edges (1) of the teeth (2) narrow alternately form the right- and left-hand sides, through flat recesses (3). Their width is 0.5 to 0.9 parts of the blade (5) width Si1 and their depth is 0.01 to 1 mm. They form planes that are parallel to the axis of rotation of the blade. The narrowed teeth (2) are arranged on the blade (5) such that they fit alternately and in mirror like manner with the right-hand and left-hand plane (6) of the blade (5). A bevel (4), the plane of which forms with the recess (3) plane an angle {alpha} being equal to 0.1 to 60 degrees, follows up laterally the blade (5) recess (3). The tooth (2) cutting edge (1) is made of material that is identical with the material of the blade (5) or metal carbides or ceramic materials.

Description

Technical field

BACKGROUND OF THE INVENTION The present invention relates to the toothing of saw blades with tapered teeth, particularly for cutting solid or hollow metal profiles and composite materials.

BACKGROUND OF THE INVENTION

Toothed saw blades have long been used for sawing wood, wood materials and plastics. They are increasingly being used for metal cutting because of their smooth cutting, minimal waste and relatively high productivity. The teeth shapes of the saw blades have been known and settled for a long time, and as a result, the development of productivity and cutting performance of metal materials has to some extent stagnated. Several types of saw teeth are known which are considered standard, for example, a straight type A tooth having a straight tooth face and a straight rake inclined at an angle of 10 to 20 °. It is suitable for cutting bronze and brass. The AW-type tooth has a similar shape, except that the cutting edges of the teeth are chamfered laterally from one side to the other. Saw blades with such treated teeth are designed for cutting thin-walled steel profiles.

However, saw blades that have a straight tooth and a round back are more frequently used. An example of such a tooth is an arched tooth B. It is suitable for cutting steel pipes and profiles of low thickness. The beveled tooth version of this tooth is referred to as BW. Tzv. the arcuate tooth, the scoring / scoring has a toothing arranged such that every other tooth is chamfered from both sides, while the teeth between them are bevelled. Blades with such teeth are suitable for solid profiles of ferrous and non-ferrous metals.

Another variant is R discs with arcuate teeth and splitting groove. The splitting groove, alternately eccentrically positioned at one or the other edge of the tip of the tooth edge, functions as a chip splitter. The purpose of the splitter is to split the chip into smaller parts and prevent it from sticking to the blade. A variant of the BR wheel is the so-called vario-tooth, called VBR, which is characterized by periodically variable tooth pitch. Like the BR wheel, it has an alternately eccentrically positioned groove on the cutting edge that acts as a chip splitter.

Said saw blade teeth solutions are currently at the peak of their capabilities and do not allow further performance gains. Factors that limit the performance of saw blades for metal cutting are, in particular, burning by insufficient blade cooling, burning of chips to the blade and clogging of teeth. The purpose of the present invention is to propose a new saw blade shape that overcomes features with known tooth shapes. The solution of the saw teeth identical or at least similar to the teeth according to the present solution is currently not known.

SUMMARY OF THE INVENTION

The tooth shape of the saw blade according to the invention is essentially based on the classical shape of the saw teeth. A conventional saw tooth has a sharp blade over the entire width of the saw blade, which is usually 1 to 6 mm wide, followed by a straight or arcuate back. The tooth edge of the present invention is, in contrast to a conventional tooth, on the side facing the center of the disc tapered by a shallow recess that is 0.01 to 1 mm deep and forms a surface on which lateral bevels can form. = 0.1 to 60 °.

The tapered teeth are positioned alternately on the right or left side of the blade so that they are flush with one or the other plane of the blade. This type of tooth is referred to as lightweight "NW-tooth" on hard

- 1 CZ 303739 Β6 materials. The number and size of the teeth depends on the diameter of the disc and ranges from 24 to 1000 teeth depending on the diameter of the disc.

The width of the tapered tooth edge Si is:

S ₂ = 0.5 to 0.9 S | (where S | = blade width), the cutting edge having a width of 0? 5 S, has an allowance of 0.01 mm so that the engagement and the chip taken by successive tooth edges overlap.

For the other cutting widths (if S?> 0.587 Si), the addition is not necessary, since the cutting width of the cutting edges overlap in these cases. Depending on the thickness of the disc, the recess depth h is between 0.01 and 1.0 mm. H = The depth of the heel depends on the diameter of the disc and the number of teeth.

The tooth edge of the present invention has a number of advantages over the prior art teeth. The shape of the tooth, which in accordance with customary designation as NW has these advantages.

a) the blade has a width of at least 50% of the width of a normal tooth, the tooth always having a width equal to the thickness of the blade. The force acting on the blade length unit is thus approximately twice the normal blade width. As a result, the blade penetrates into the material more easily and with less cutting waste,

b) less deformation of the walls in large thin-walled profiles,

c) full blade thickness (up to 15 mm) is maintained, which means that the blade retains maximum strength even when the blade is tapered and does not break or break the teeth and, in comparison with BR or BS teeth, does not damage the saw blade mechanically,

d) allows better air flow to individual teeth, which results in better cooling and prevents their overheating,

e) allows a better passage of coolant to the next cutting edge,

f) extrusion of material is eliminated compared to teeth BW or C,

g) much longer tool life is achieved when cutting hard materials and stainless steels,

h) higher resistance to dulling due to blade overheating is achieved compared to BR or BS.

The blades of the saw blade may be made of a material identical to that of the saw blade or may be made of metal carbides and ceramic blades (so-called cermets) brazed to the teeth of the saw blade.

Overview of the drawings

FIG. 1 shows a cross-section A-A ‘of the tooth profile NW of the tooth at the base of the tooth and with a recess forming an angle of 0 ° with the axis of rotation. Fig. 2 shows a cross-section B-B ‘of the tooth tip NW of the tooth base at the tooth base, whose recess is provided with a bevel of ct = 45 ° which forms the recess plane with the rotational axis of the saw blade. FIG. 3 shows the NW teeth of the saw blade with a recess plane parallel to the rotational axis of the saw blade. Fig. 4 shows the saw teeth of the saw blade with a bevel laterally adjacent to the recess with an angle α = 45 ° with respect to the rotational axis of the saw blade.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The saw blade teeth of 3.5 mm thickness according to the example shown in Fig. 2 have a rounded tooth 2 and an arcuate spine 8, with the tooth edges f having a width of 1.76 mm to the center of the blade thickness and arranged in two adjacent rows that each row of blades alternates with the right or left plane 6 of the saw blade. The recesses 3 are arranged as flats that are parallel to the axis of rotation of the disc 5 and their transverse dimension is parallel to the axis of rotation of the disc 6. The disc 5 has a diameter of 450 mm and 200 teeth.

Example 2

The 3.5 mm saw blade teeth of the example shown in Fig. 3 have an arcuate spine 8 and a round tooth 2, with the blades 1 having a width of 1.76 mm to the center of the blade thickness and arranged in two adjacent rows so that The blade 5 has a bevel 4 at an angle cc = 45 ° relative to the axis of rotation of the blade 5. The blade 5 has a diameter of 450 mm and 200 teeth.

Industrial applicability

The invention is industrially applicable for the production and grinding of saw blades with tapered tooth edges, which are particularly suitable for cutting on solid or solid metal profiles, plastics and composites on an industrial scale.

Claims (2)

25 PATENT CLAIMS 1. Toothing of a saw blade intended in particular for cutting solid or hollow metal and composite profiles, characterized in that the blades (1) of the teeth (2) are alternating from right and left 30 sides laterally tapered by flat recesses (3) 0.1 to 0.5 widths wide (S |) of the disc (5) with a depth of 0.01 to 1 mm, forming planes parallel to the axis of rotation of the disc, the tapered teeth (2) 1) are arranged on the disc (5) so as to align alternately and mirrored with the right and left planes (6) of the disc (5). Saw blade toothing according to Claims 1 and 2, characterized in that a bevel (4) is laterally connected to the recess (3) of the blade (5), the plane of which is at an angle α = 0.1 to 60 ° with the recess (3). . A saw blade toothing according to claims 1 to 4, characterized in that the cutting edge (1) of the tooth (2) is of a material identical to that of the blade (5) or of metal carbides or ceramic materials. 3 drawings -3 CZ 303739 B6 1 sec. X 4 --- --------- ! and -4 - ► xs ₂ OF' Z z z _z z z ^x z z Z Z _x z z ^x x / Z / 2zZ HP section A-A ' Giant. 1 -4GB 303739 B6 cut B-B ' Giant. 2 2 3 Giant. 3 Giant. 4 End of document