EP3865216A1 - Device for grinding metal chips - Google Patents

Abstract

The invention relates to a device (10) for comminuting metal chips (12) with at least one rotatably mounted knife shaft (20) to which at least two cutting modules (40) are detachably attached. The cutting modules (40) are each placed individually on the at least one knife shaft (20) and are detachably fastened in such a way that at least two cutting modules (40) are present in the direction of rotation (26) of the knife shaft (20). The device (10) also has a motor drive for rotating the at least one knife shaft (20) and at least one fixed knife bar (50) which interacts with the cutting modules (40) of the at least one knife shaft (20). According to the invention, there is at least one endless conveyor (60) for the metal chips (12), the metal chips (12) transported by the endless conveyor (60) being brushed off by the endless conveyor (60) by the cutting modules (40) attached to the knife shaft (20) can. The at least one knife shaft (20) is arranged above the endless conveyor (60) or approximately at the same height as the endless conveyor (60).

Description

TECHNICAL AREA

The invention relates to a device for comminuting metal chips. When operating lathes, large quantities of metal chips, for example steel chips, are regularly produced. These metal chips are transported away from the lathe by means of an endless conveyor and conveyed into a container. By means of a device for comminuting metal chips, the volume of the metal chips can be significantly reduced so that these containers have to be emptied less frequently.

STATE OF THE ART

In the metalworking industry in particular, there are often very long, spiral-shaped and sharp-edged metal chips that require a large amount of space. If these chips get entangled with one another, this leads to the formation of clusters of chips, which can require even more space. The metal shavings are a reusable raw material that is collected in containers for recycling. The existing container volume has long since been regularly reached, although the weight of the container could still be full. It is therefore advantageous to obtain the smallest possible chips in order to reduce the volume requirement of the chips and thus to be able to accommodate the largest possible mass of chips in a container.

The chips are regularly very sharp-edged, so that the chips cannot be compressed with bare hands in order to create more space in the container. The risk of injury to employees would be too great. For this purpose there are devices for comminuting known from metal chips that have one or more rotatable shafts, each equipped with cutting blades. A corresponding device is, for example, from DE 44 06 675 A1 famous. Several disc-shaped cutting knives are pushed one behind the other onto the rotatable knife shaft and attached to the knife shaft in this threaded sequence.

The individual cutting teeth of the cutting blades can become blunt or break off during operation, which makes it necessary to replace the cutting blades. In this case, the knife shaft with all cutting knives must be removed from the housing so that the outer cutting knives can be removed from the knife shaft up to the cutting knife to be replaced. After replacing the defective cutting knife with a new cutting knife, the removed, functional cutting knife must be reattached to the knife shaft and this must then be reinstalled in the housing. Such a repair process is associated with a high expenditure of time and work and is therefore economically unfavorable. In addition, it is not possible to shred the chips during the repair process, which can possibly also result in a production stop on the lathes.

For this reason, devices for comminuting metal chips are known in which the rotatable knife shafts are each equipped with several cutting knife modules that can be placed individually on the knife shafts and are detachably attached to the knife shaft that, viewed in the direction of rotation of the knife shaft, at least two cutting modules are available. Corresponding devices are, for example, from DE 20 2009 017 062 U1 famous.

These devices are separate devices that are often not available next to the lathe. If there is no endless conveyor from the lathe to the device for comminuting metal chips, the chips have to be closed manually transported to the device and are often also fed manually to the device there. Here, too, there is again the risk of injuries from the sharp-edged chips. From the EP 3 178 560 A1 Therefore, a device for comminuting metal chips is known in which the knife shaft is positioned so close to the endless conveyor that the metal chips transported by the endless conveyor can be stripped off by the cutting modules of the knife shaft. The endless conveyor and the knife shaft are driven by a common motor drive.

In particular, in the case of very long chips, the metal chips can already get tangled on the endless conveyor. This can lead to the chips no longer falling from the endless conveyor into the device for comminuting metal chips, but instead getting stuck on the endless conveyor. This can lead to clogging of the endless conveyor, which can lead to a production stop. In such a case, the endless conveyor must be opened and the swarf drawn in must be removed before the endless conveyor can be operated again. Such maintenance work is time-consuming and therefore economically disadvantageous. The removal of the metal chips also usually has to be carried out manually, which increases the risk of injury from the sharp-edged metal chips.

DISCLOSURE OF THE INVENTION

Proceeding from this known prior art, the invention is based on the object of specifying an improved device for comminuting metal chips which enables operation with as little maintenance as possible.

The device according to the invention for comminuting metal chips is given by the features of main claim 1. Useful further developments of the invention are the subject of further claims which follow this claim.

The device according to the invention for comminuting metal chips has at least one rotatably mounted knife shaft. At least two cutting modules can be detachably attached to each knife shaft, which cooperate with at least one fixed knife bar and thereby cause the chips to be comminuted. The cutting modules can each be placed individually on the knife shaft and detachably fastened to the knife shaft in such a way that at least two cutting modules are present in each case, viewed in the direction of rotation of the knife shaft. In addition, the device can be positioned in such a way that the metal chips transported by an endless conveyor can be stripped off the endless conveyor by the cutting modules attached to the knife shaft. According to the invention, the at least one knife shaft is arranged above the endless conveyor or approximately at the same height as the endless conveyor.

By arranging the at least one knife shaft above or at the same height as the endless conveyor, the scraping of the metal chips can take place particularly effectively. In addition, no more balls of chips can form between the endless conveyor and the housing of the endless conveyor, since the chips are shredded in good time beforehand by the knife shaft.

In a first embodiment, the endless conveyor can have a first conveying area which runs approximately horizontally. This first conveying area can be followed by a second conveying area which rises so that a concave area of the endless conveyor results. In this case, the at least one knife shaft can be arranged in this concave area of the endless conveyor.

In particular, in the concave area of the endless conveyor at the transition between the horizontal conveying area and the ascending conveying area, the metal chips tend to form agglomerations. The metal chips can easily get caught in this area and disrupt the regular flow of transport in this way. If the cutting modules already act at this point on the endless conveyor, this tangle formation can be effectively prevented, so that trouble-free operation of the endless conveyor and thus also of the lathes is possible.

As an alternative or in addition to the concave area of the endless conveyor, the endless conveyor can in a second embodiment have a first circulating conveyor belt and a second circulating conveyor belt, which are present immediately one behind the other, so that the metal chips are transferred from the first circulating conveyor belt to the second circulating conveyor belt. In this transition area between the conveyor belts, the metal chips can also increasingly form tangles. The knife shaft can therefore be arranged in this transition area, so that the cutting modules can already engage at this point. As a result, the formation of a tangle can be effectively prevented, so that trouble-free operation of the endless conveyor and thus also of the lathes is possible.

In a third embodiment, which can also be used as an alternative or in addition to the two first embodiments, the at least one knife shaft can be arranged in front of the endless conveyor as viewed in the transport direction of the endless conveyor. the The axis of the at least one knife shaft can be arranged approximately at the level of the reversal point of the endless conveyor. In this way it can be prevented that the metal chips accumulate on the housing of the endless conveyor shortly before the end of the endless conveyor and that a tangle is formed in this way.

The modular type of attachment of the individual cutting modules makes it possible to detach a defective cutting module individually from the knife shaft and replace it without affecting other, neighboring cutting modules. It is also not necessary to remove the knife shaft from the housing. The replacement of the individual cutting modules is therefore uncomplicated and quick, so that the device only has a short downtime during maintenance.

The cutting modules can be attached to the knife shaft via at least one screw connection. The individual cutting modules can preferably each be screwed to the knife shaft with at least two screws. This type of attachment is easy to implement and enables a firm and permanent attachment that can withstand greater forces.

The individual cutting modules each have at least one cutting tooth which cooperates with the fixed knife strip of the device in order to comminute the metal chips. The cutting modules can be designed in such a way that there is only one single cutting tooth per cutting module. In an alternative embodiment, several cutting teeth can be present per cutting module. This can be implemented, for example, in that, with the cutting module of the same size, instead of a central cutting tooth, at least two lateral, external cutting teeth are present. As an alternative or in addition to this, the cutting module could be made correspondingly larger and have several cutting teeth.

In a preferred embodiment, the rotatably mounted knife shaft can have several pockets in its outer surface, in each of which a cutting module can be positioned. As a result, in addition to the fastening, simple positioning of the individual cutting modules on the knife shaft can also be made possible, which can be particularly desirable for the initial assembly of the individual cutting modules. The cutting modules can be inserted exactly into the pockets and have a precisely defined position in relation to neighboring cutting modules, so that an optimal cutting result can be achieved. The assembly and replacement of the cutting modules can still take place quickly, so that only a short assembly time is required for the initial assembly as well as for the replacement of one or more cutting modules. The pockets can preferably be milled into the outer surface.

It has been found to be advantageous to design the pockets with a circular cross-section. The pockets can be attached in a structurally simple manner by means of a solid drill, so that the manufacturing costs can be reduced. In this case, the cutting modules can preferably have a circular base which can be inserted into the pockets of the knife shaft. The circular cross-section of the pockets and the base of the cutting modules reduces the wear and tear on the cutting modules and deformations of the cutting modules and of the screws for fastening the cutting modules to the knife shaft. This also makes it easier to change the cutting modules, since the screws can be loosened more easily.

The rotatably mounted knife shaft can preferably be of cylindrical design. The cross section of the rotatably mounted knife shaft would in this case - apart from the pockets present in the lateral surface - be circular.

The fixed male connector can also have a modular design. For this purpose, the knife bar can have several knife units that for example, can be attached to a common knife holder. As a result, the individual modules of the fixed male connector can also be easily exchanged if one of the knife units is defective. The individual knife units can be attached, for example, using one or more screws.

The device according to the invention can be purchased and set up together with a corresponding endless conveyor. However, it would also be possible to retrofit an existing endless conveyor accordingly. The knife shaft can therefore preferably have a separate motor drive. In this way, the endless conveyor and the knife shaft can each be driven separately via their own motor drives. In order to enable optimal operation of the device according to the invention, the knife shaft and the endless conveyor should be connected to one another in such a way that a predefined distance between the individual cutting modules and the conveyor belts of the endless conveyor is maintained. For this purpose, the housing of the knife shaft can preferably be firmly connected to the housing of the endless conveyor.

Further advantages and features of the invention can be found in the features further specified in the claims and in the exemplary embodiments below.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1

einen schematischen Querschnitt durch eine erste Ausführungsform der erfindungsgemäßen Vorrichtung,

Fig. 2

eine Seitenansicht der Messerwelle der erfindungsgemäßen Vorrichtung ohne in die Taschen einzusetzende Schneidmodule,

Fig. 3

einen Querschnitt durch die Messerwelle gemäß Fig. 2,

Fig. 4

eine Draufsicht auf ein in die Taschen der Messerwelle einzusetzendes Schneidmodul,

Fig. 5

eine Seitenansicht des Schneidmoduls gemäß Fig. 4, und

Fig. 6

einen schematischen Querschnitt durch eine zweite Ausführungsform der erfindungsgemäßen Vorrichtung.

The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the drawing. Show it:

Fig. 1

a schematic cross section through a first embodiment of the device according to the invention,

Fig. 2

a side view of the knife shaft of the device according to the invention without cutting modules to be inserted into the pockets,

Fig. 3

a cross section through the knife shaft according to Fig. 2 ,

Fig. 4

a top view of a cutting module to be inserted into the pockets of the knife shaft,

Fig. 5

a side view of the cutting module according to Fig. 4 , and

Fig. 6

a schematic cross section through a second embodiment of the device according to the invention.

WAYS OF CARRYING OUT THE INVENTION

A first embodiment of the device 10 according to the invention for comminuting metal chips 12 is shown schematically in FIG Fig. 1 shown. The device 10 has a knife shaft 20 which is rotatably mounted in a bearing block 22. The knife shaft 20 can be rotatably driven about the axis of rotation 24 by means of a motor drive (not shown). The direction of rotation 26 runs counterclockwise in the present example.

In the present example, the knife shaft 20 has a circular cross section. In the present example, several pockets 32 are present in the lateral surface 30, each of which has a circular cross-section (see FIG Fig. 2 ). A cutting module 40 (see FIG Figures 4 and 5 ) are inserted and fastened. For this purpose, the cutting modules 40 have a circular base 42, the diameter of which is adapted to the diameter of the pockets 32. Each cutting module 40 has a cutting tooth 44 which is arranged in the center of the base 42. The cutting modules 40 also each have a bore 46 into which a screw 48 engages can, in order to fasten the cutting modules 40 to the knife shaft 20 by means of a screw connection.

The cutting modules 40 can be removed from the knife shaft 20 individually. After loosening the fastening screw 48, the cutting module 40 to be exchanged can be removed from the knife shaft 20. The knife shaft 20 itself does not have to be removed from the bearing block 22 for this purpose. There is also no need to remove any further cutting modules 40 which are not intended to be exchanged. The replacement of defective cutting modules 40 is therefore quick and unproblematic and is therefore economically advantageous.

The cutting teeth 44 of the cutting modules 40 cooperate with a stationary knife bar 50 in order to comminute the metal chips 12. The fixed male connector 50 is fastened to a knife holder 54 by means of a plurality of screws 52. The knife holder 54 itself is attached to the bearing block 22 for the knife shaft 20.

In the present example, the knife strip 50 has a modular structure and has a plurality of knife units 56. The number of knife units 56 can correspond to the number of cutting modules 40 viewed in the longitudinal direction of the knife shaft 20. The individual knife units 56 are each fastened to the knife holder 54 via one or more screws 52. Due to the modular structure of the fixed knife strip 50, the individual knife units 56 can also be easily exchanged in the event of a defect.

The device 10 also has an endless conveyor 60 for metal chips 12. The endless conveyor 60 is placed so close to the rotatably mounted knife shaft 20 that the individual cutting modules 40 can serve as scrapers for the metal chips 12. The endless conveyor 60 has a first conveying area 62 which runs approximately horizontally. This first conveying area 62 is followed by a second conveying area 64 which rises. Between these two conveying areas 62, 64 there is thus a concave area 66 of the Endless conveyor 60. In this concave area 66 of the endless conveyor 60, the metal chips 12 increasingly form balls. The knife shaft 20 is therefore placed in this concave area 66 of the endless conveyor 60. In this way, tangling can be effectively prevented

It has been found to be sufficiently close if the distance between the cutting teeth 44 of the cutting modules 40 and the conveyor belt 68 of the endless conveyor 60 is approximately two centimeters. With this spacing, it can be ensured that the cutting teeth 44 cannot damage the conveyor belt 68; at the same time, the regularly very long metal chips 12 can be reliably taken along by the cutting modules 40 in this way.

In Fig. 6 a second embodiment of the device 10.2 according to the invention for comminuting metal chips 12 is shown schematically. The device 10.2 has a knife shaft 20.2 which is rotatably mounted in a bearing block 22.2. The knife shaft 20.2 can be rotatably driven about the axis of rotation 24 by means of a motor drive (not shown). In the present example, the direction of rotation is clockwise. The knife shaft 20.2 essentially corresponds to the knife shaft 20, which is in the Figures 2 to 5 is shown.

The cutting teeth 44 of the cutting modules 40 of the knife shaft 20.2 cooperate with a stationary knife bar 50.2 in order to comminute the metal chips 12. The fixed male connector 50.2 is attached to a knife holder 54.2 by means of several screws. In the present example, the male connector 50.2, like the male connector 50, has a modular structure.

The device 10.2 also has an endless conveyor 60.2 for metal chips 12. The endless conveyor 60.2 is arranged in a housing 70. The drive shaft 72 of the endless conveyor 60.2 is rotatably supported in the housing 70. Especially in the end of the Endless conveyor 60.2, there is an increased formation of balls, since the individual metal chips 12 catch on the housing and can accumulate in this way. The endless conveyor 60.2 is therefore placed so close to the rotatably mounted knife shaft 20.2 on the one hand that the individual cutting modules 40 can serve as scrapers for the metal chips 12. In addition, the knife shaft 20.2 is arranged with its axis of rotation 24 at the same level as the drive shaft 72 of the endless conveyor and thus at the level of the reversal point of the endless conveyor 60.2. In this way, tangling can be effectively prevented.

In the present example, both the knife shaft 20.2 and the endless conveyor 60.2 rotate clockwise. In principle, however, it would also be possible to have the knife shaft 20.2 rotate in a counterclockwise direction.

In principle, it is possible to equip an endless conveyor with several rotatably mounted knife shafts for comminuting the metal chips. For example, it would be possible to have a first rotatably mounted knife shaft in the concave area relative to the beginning of the endless conveyor Fig. 1 to be provided. In the end area of the endless conveyor, a further rotatably mounted knife shaft could also be provided accordingly Fig. 6 be arranged.

Claims (9)

Device (10, 10.2) for crushing metal chips (12) - With at least one rotatably mounted knife shaft (20, 20.2) to which at least two cutting modules (40) are detachably attached, the cutting modules (40) each being placed individually on the at least one knife shaft (20, 20.2) and thus detachably attached, that, viewed in the direction of rotation (26) of the knife shaft (20, 20.2), there are in each case at least two cutting modules (40), - With a motor drive for rotating the at least one knife shaft (20, 20.2), - With at least one stationary knife strip (50, 50.2) cooperating with the cutting modules (40) of the at least one knife shaft (20, 20.2), - With at least one endless conveyor (60, 60.2) for metal chips (12), wherein the metal chips (12) transported by the endless conveyor (60. 60.2) are removed from the endless conveyor (40) by the cutting modules (40) attached to the knife shaft (20, 20.2). 60, 60.2) can be stripped off, - characterized in that - The at least one knife shaft (20, 20.2) is arranged above the endless conveyor (60, 60.2) or approximately at the same height as the endless conveyor (60, 60.2). Device according to claim 1, - characterized in that - The endless conveyor (60) has a first conveying area (62) which runs approximately horizontally, and a second conveying area (64) which adjoins the first conveying area (62) and rises, so that a concave area (66) of the endless conveyor (60) results, - The at least one knife shaft (20) is arranged in the concave area (66) of the endless conveyor (60). Device according to claim 1 or 2, - characterized in that - the endless conveyor has a first revolving conveyor belt and a second revolving conveyor belt, which are present directly one behind the other, so that the metal chips can be transferred from the first revolving conveyor belt to the second revolving conveyor belt, - The at least one knife shaft is arranged in the transition area between the first revolving conveyor belt and the second revolving conveyor belt. Device according to one of Claims 1 to 3, - characterized in that - The at least one knife shaft (20.2) is arranged in front of the endless conveyor (60.2) as seen in the transport direction of the endless conveyor (60.2), - The axis of rotation (24) of the at least one knife shaft (20.2) is arranged approximately at the level of the reversal point (72) of the endless conveyor (60.2). Device according to claim 4, - characterized in that - The direction of rotation of the endless conveyor (60.2) corresponds to the direction of rotation of the at least one knife shaft (20.2). Device according to one of the preceding claims, - characterized in that - the rotatably mounted knife shaft (20) has several pockets (32) in its outer surface (30), - A cutting module (40) can be inserted into each of the pockets (32). Device according to claim 6, - characterized in that - the pockets (32) have a circular cross-section. Device according to claim 7, - characterized in that - the cutting modules (40) have a circular base (42), - The circular base (42) can be inserted into the pockets (32) of the knife shaft (20). Device according to one of the preceding claims, - characterized in that - the rotatably mounted knife shaft (20) is cylindrical, - The knife shaft (20) has a circular cross-section.

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