EP0713726A2 - Metal-chip comminuting device - Google Patents

Abstract

Swarf is crushed in an arrangement of two counter-rotating shafts (5, 6) in a crushing chamber (4), on which knives (7) are mounted, spaced from each other. The knives produce a shear action with blades of the adjacent shaft and have a curvature dependent on the radius. A screen is located below the knives, with screen holes only under respective knives. Additional flushing holes are pref. provided under the intermediate spaces between the knives. The screen is mfd. from a steel contg. (%) 0.15-0.22 C, 0.20-0.65 Si, 1.0-1.7 Mn, 0.025 max. P. 0.025 max. S, 0.80-1.5 Cr, 0.50 max. Cu, 0.30 max. Mo, and 0.60 max. Ni.

Description

The present invention relates to a chip shredder according to the preamble of the main claim.

Chip shredders of this type are used to shred the chips produced in the machining of metal, plastic or wood workpieces in lathes, milling machines or automatic processing machines. Because of their contamination and poor handling, these chips represent a problem in the reuse (recycling) of the chip material. The chip shredders that have been known in this way are not yet suitable in terms of their performance in terms of their susceptibility to malfunction and safe continuous crushing and service life fulfill.

The present invention is therefore based on the object of proposing an improved chip shredder, in particular for metals.

This object is achieved by a chip shredder with the features of the main claim. Further advantageous refinements can be found in the subclaims.

To this end, the chip shredder designed according to the invention has a sieve which is only provided with sieve holes under the respective knife. The diameter of the screen holes depends on the size and type of chips to be processed or the desired size of the chips. The thickness of the sieve must also be adjusted accordingly. By arranging the sieve holes only under the respective knife, the chips are rubbed by the knives over the holes until the respective chip is small enough to pass through the sieve holes. Because of this arrangement, there are hardly any shredded chips, so that the operational safety of the device is ensured. This shredding of the chips also enables the chip chips to be automatically removed from the machine.

According to a preferred embodiment, rinsing bores are additionally arranged between the individual rows of the screen holes. The rinsing holes are located under the gaps between the knives arranged on a shaft. Using the flushing holes, smaller chips that accumulate in this area can be flushed away using a flushing liquid.

According to a further preferred embodiment, the screens are made of steel as a sheet metal part with the alloy additives 0.15-0.22% carbon, 0.20-0.65% silicon, 1.0-1.7% manganese, ≦ 0.025% phosphorus, ≦ 0.025% sulfur, 0.80-1.5% chromium, ≦ 0.50% copper, ≦ 0.30% molybdenum and ≦ 0.60% nickel. Such a material is known under the designations VSS 295 and VSS 296 with the materials no. 1.8704 and 1.8705 and ensures a long service life when shredding metal chips. It is only through the use of such a material that it is ensured that the metal chips can be shredded over a long period of time without disruption.

To remove larger non-cut objects that can get into the chip shredder, a magnet is additionally provided, which can be inserted into the gusset between the knives to remove these parts. If magnetic, these objects can be removed using the magnet. The knives stick to the magnetic (iron) workpieces so that the device comes to a standstill. The knives are then moved in the opposite direction of rotation by means of a corresponding control in order to release the space and, if appropriate, the workpiece for removal by the magnet. Due to the power of the knives, it can be expected that non-magnetic parts will gradually be scraped off and crushed. The knives used for the chip shredder have a disk-shaped knife body from which at least two hook-shaped knife teeth protrude, the inner radii of which point in the direction of rotation. These knife teeth are used to pull the chips down and to shred them between the edges of the knife body that are juxtaposed. The further comminution then takes place between these knife teeth and the inner surface of the sieve until the chip chips fit through the respective sieve holes. According to a preferred embodiment, the knives have at least two essentially symmetrical knife teeth which protrude from the knife body and are hook-shaped in both directions of rotation. These knives are particularly advantageous when crimp-like shavings are placed around the shafts so that they can no longer be grasped and shredded by the knives of the other row of knives. These specially designed knife teeth are then used for reversing the direction of rotation for broaching and subsequent comminution.

The chip shredder designed in accordance with the invention is characterized by a long service life and operational reliability and allows the safe shredding of all chips and chip shapes that occur.

The invention is explained in more detail below on the basis of exemplary embodiments in conjunction with the accompanying drawings.

Figur 1

eine Draufsicht auf einen Spänezerkleinerer;

Figur 2

einen Querschnitt durch den Spanzerkleinerungsraum;

Figur 3

die Draufsicht auf ein Sieb;

Figur 4

die Draufsicht auf ein anderes Ausführungsbeispiel einer Siebhälfte;

Figur 5

die Ansicht einer Messerausführungsform; und

Figur 6

die Ansicht einer anderen Messerausführungsform.

They represent:

Figure 1

a plan view of a chip shredder;

Figure 2

a cross section through the chip shredding room;

Figure 3

the top view of a sieve;

Figure 4

the top view of another embodiment of a screen half;

Figure 5

the view of a knife embodiment; and

Figure 6

the view of another knife embodiment.

Figure 1 shows the chip shredder 1 with a motor 2, a gear 3 and the chip shredding room 4. In the chip shredding room 4 there are two shafts 5 and 6 on which two rows of knives are arranged. The knives 7 of a row of knives are arranged at a distance from one another and mesh with the knives of the second row of knives. The spacing of the shafts from one another is designed such that the knives 7 protrude as far as possible into the space 8 between the knives of the other row of knives. The chips are pre-shredded by the shear effect between the individual knife bodies. The schematically indicated magnet 9 can be extended via the knives and serves to remove larger parts from the chip shredding area.

FIG. 2 shows the chip shredder with the shafts 5 and 6 arranged in the chip shredding chamber 4 and the knives 7 located thereon. Below the shafts there is a sieve 10 with curved sieve surfaces, the radius of which corresponds to the radius of the knife teeth 11, so that the distance between the knife tooth 11 and the surface of the sieve 10 is as small as possible. The distance depends on the size of the chips you want. The crushing takes place by rubbing the chips between the knife teeth 11 and the surface of the sieves 10. The sieves are made of the particularly wear-resistant material VSS 295. The cutting speed of the knives is 5 to 12 meters per minute depending on the amount to be shredded and the size of the chips.

Figure 3 shows an embodiment of a sieve 10. It can be clearly seen that the sieve holes are each arranged only under the respective knife. The two halves of the screen are rotated 90 ° against each other.

FIG. 4 shows another embodiment of a sieve 10, only one half of the sieve being shown here. In this embodiment, rinsing holes 13 are still provided between the individual sieve holes 12 for cleaning the sieve and removing smaller parts.

FIG. 5 shows a knife 7 with four knife teeth 11 ′, which are configured symmetrically and protrude from the knife body 15. The knife teeth 11 'are hook-shaped on each side, so that this knife shape is suitable for removing chips wound around the shaft by reversing the direction of rotation and feeding them in an orderly comminution.

FIG. 6 shows another embodiment of a knife 7 with knife teeth 11 ″ which are hook-shaped only on one side in order to take the chips with this side and to feed them down.

Claims (6)

Chip shredder with two counter-rotating shafts, on which are spaced knives, each meshing with a shear effect in the space between the knives on the other shaft, and a sieve below the knife, which corresponds to the radius of the knives on a shaft Knife is curved, characterized in that the sieve holes (12) are arranged only under the respective knife (7). Chip shredder according to claim 1, characterized in that additional rinsing holes (13) are provided under the spaces (8) between the knives (7) arranged on a shaft (5, 6). Chip shredder according to claim 1 or 2, characterized in that the sieves are made of steel sheet with the alloy proportions 0.15-0.22% carbon, 0.20-0.65% silicon, 1.0-1.7% manganese, ≦ 0.025% phosphorus, ≦ 0.025% sulfur, 0.80-1.5% chromium, ≦ 0.50% copper, ≦ 0.30% molybdenum and ≦ 0.60% nickel. Chip shredder according to one of the preceding claims, characterized in that a magnet (9) is provided which can be inserted into the gusset between the knives (7) in order to remove large parts. Chip shredder according to one of the preceding claims, characterized in that the knives (7) have a disk-shaped knife body (14) from which at least two hook-shaped knife teeth (11 '') protrude, the inner radii of which point in the direction of rotation. Chip shredder according to one of the preceding claims 1 to 4, characterized in that the knives (7) have a disk-shaped knife body (14) from which at least two essentially symmetrical knife teeth (11 ') protrude, which are hook-shaped in both directions of rotation.

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