EP1255612B1 - Method and device for reducing cuttings - Google Patents

Abstract

A method and two apparatuses for comminuting chips are presented. Chip breakers without a coarse-part ejecting element are often used for comminuting chips. Blocking constituents therefore have to be removed with great effort, for example by hand. If a coarse-part ejecting element is present, there is no differentiation between blocking hard parts and blocking clumps of chips, but instead both types are ejected. It is now envisaged to subdivide blocking constituents in horizontal chip breakers into categories, depending on the negative acceleration of the shaft (3, 17, 18) caused by the blocking, and to assign to each category a defined reversing operation for loosening the blocking constituents and, if appropriate, discharge from the comminuting space (1, 15) by means of a coarse-part ejecting element (12, 32).

Description

The invention relates to a method for shredding chips in a shredding room between a driven, rotatable in both directions, with shear elements, horizontal shaft and associated counter shear elements, with chips entered from above crushed and discharged down over a perforated screen bottom and blocking Components that cause a shaft standstill are discarded after reversing the shaft become. The invention further relates to two devices for performing the inventive method.

The comminution of chips in horizontal chip breakers is known from DE 94 18 904 U1. Here are chips that are used in the processing of workpieces made of metal, plastic or Wood in a shredding room between two electrically driven shafts, their shear blades interlock as they rotate, shredded and over a perforated plate discharged. If a large part gets caught between the two shafts and thus one If the waves come to a standstill, then the waves can be stopped by means of a corresponding Control can be moved in the opposite direction of rotation .. In general, then Blocking large part by hand or with magnetic parts using magnets from the Shredding room can be removed. Every time it comes to removing large parts to standstills and thus reduced throughput rates. In addition, the use of Personnel necessary.

EP 0 717 663 B1 describes a vertical chip breaker for steel or metal chips with a Coarse part ejection element known. This single-shaft crusher consists of a receiving funnel and a grinding funnel adjoining at the bottom with a circumferentially distributed arrangement Rice blocks, on the edges of which are attached to a rotating cutter head Rice knives are movable past. A grinder connects below the grinding funnel. In the lower area of the grinding funnel one is closed by means of a power-driven channel slide opening chute provided for coarse parts. If there is a large part between the Chip material is located, then this lies on the grinder and is from the cutter head rotated together with the chips until there was a blockage of the Knife head comes. A slow reversal process is used to remove the blockage initiated and the large part ejection element opened, so that the interference elements from the cutter head can be transported to and through the ejection.

A disadvantage of this design is that it cannot be used for horizontal chip breakers. In addition, if the rotary movement of the cutter head is impaired, distinguish between dense tufts of chips and coarse parts or combinations of the two. Experience has shown that dense tufts of chips often lead to a blockage can. These tufts are also removed here via the ejection and thus the Shredding process withdrawn.

The object of the above invention is now a method and two To provide devices of the type mentioned in the introduction, wherein a Horizontal chip breaker is provided which divides the blocking components into groups, e.g. dense tufts of chips, pure coarse parts, differentiates and each group a defined Reversing process and, if necessary, a discharge from the comminution area via a Assigns coarse part ejection element.

According to the invention a method is provided in which the Speed of change in the load of the driven, loaded with shear elements Wave is detected., Due to the detected speed of change in load taking into account the type, amount, and / or size of chip, the presence of blocking Components is determined and then the non-crushed blocking components ejected after one or more reversals of the shaft.

When detecting the speed of change in the load of shear elements occupied wave by blocking components shows that each component type one causes different rate of change of load. Hard, one-piece Coarse parts, e.g. Fragments of machined workpieces produce a high Rate of change in load. Very dense tufts of chips result in a lower one Rate of change in load. The value is for less dense tufts of chips even lower. It is also important to pay attention to the different chip parameters, as chips depending on e.g. break the manufacturing material differently. Now lies If there is a malfunction due to a blocking part, this can be automatically triggered by a or several reversing operations are carried out via a large part ejection element. On Intervention by the operator is not required. The shredding process is after Removal continued again. For versions where the counter shear elements are on one second shaft, it may be advantageous to control the shaft and To program the countershaft in such a way that a shaft comes to a standstill during the reversing process or reverses significantly slower than the other wave. This will cause the counteracted previously blocking components. It is also one of those Sequence of movements more likely that the blocking components are more likely due to the faster wave are taken along and thus to the same side of the shredding room to be carried.

The method according to the invention can advantageously be carried out such that Detection of the speed of change in the load of the driven, with Shear-occupied shaft, the acceleration of the shaft is detected. Hard, one-piece Coarse parts, e.g. Fragments of machined workpieces produce a high negative Acceleration. Very dense tufts of chips cause a lower negative acceleration. For less dense tufts of chips, the value is even lower. Of course, the Rate of change of load also e.g. about the change in torque of the shaft are measured using strain gauges. This would depend on the load the speed of the shaft deformation vary. Also are vibration meters conceivable, because a blockage by coarse parts would cause a higher vibration than dense tufts of chips.

The method according to the invention can be carried out such that on the basis of the determined Acceleration profile, the components causing a blockage in at least two Categories are divided, the components depending on the applicable category more or less frequently moved by reversing the shaft and either crushed or continued to be thrown back uncrushed.

Subdivision into categories allows for blocking components for each component type to design an optimized program flow. This is how compacted tufts of chips become, one Cause blocking due to the relatively low negative effects it causes Acceleration recognized as such. There may be a long period of repeated reversing Follow closed coarse part ejection element, whereby the compacted bundle of chips shreds shall be. At the end of the reversing process, dense remnants of clumps can still be present the large part ejection element to be opened are discharged. Form another category blocking coarse parts. Rough parts can e.g. Fractions of machined workpieces or screws. These coarse parts abruptly cause a high negative in the event of a blockage Acceleration. Since such components are not crushed by the shear elements is possible, a short reversing process with the coarse part ejection element open initiated to eject the bulk as quickly as possible.

It can be advantageous in the method according to the invention to increase the categories to arrange negative acceleration, with increasing negative acceleration the Frequency of reversing from category to category decreases. The firmer a blocking Component, the higher the negative acceleration in the event of a blockage and the more the likelihood of shredding this component by frequent reversing is less and end the blockade. Therefore, it makes sense to end solid objects Reverse the blockage briefly and then the component via the coarse part ejection element to be sorted out so that the shredding can continue immediately.

The method according to the invention can advantageously also be carried out in such a way that Detection of a negative shaft acceleration measured the change in speed of the drive becomes. By detecting the negative shaft acceleration via the change in speed of the The drive does not need to be recorded directly on the shaft. A detection on the shaft would be to implement only with great effort. For example, would need a sensor to prevent contamination from adhering or chip dusts penetrating into the housing are protected. An optical sensor would be not to be used due to the chips to be shredded.

Finally, the inventive method can also be carried out so that during the Reversing the shaft's rotational speed is lower than the normal rotational speed is set. Lowering the speed when reversing prevents blocking components are abruptly loosened and flung around in the shredding room. Instead, the blocking component must be loosened carefully and reversed over to carry the shaft away to the coarse part ejection element.

The aforementioned task is performed in a first device for shredding chips, which with a arranged in a shredding room, by means of drive and control in horizontal shaft with shear elements, rotatable in both directions, with this shaft assigned counter shear elements and with a curved, adapted to the waveform Perforated sieve bottom is equipped, solved by the fact that on the parallel to the shaft axis Walls of the comminution space is attached to a large-part ejection element to be opened and the counter shear elements on walls of the shaft lying parallel to the shaft axis Crushing room are arranged in two rows. It is also a controller for the Coarse part ejection element is provided, the controls of the shaft and Coarse part ejection element are networked with each other. Furthermore, the Speed of change in the loading of the shaft on the negative accelerations the shaft-detecting control provided for the coarse part ejection element and depending a variable number of reversing processes from the respective negative acceleration closed and / or open coarse part ejection element programmable.

The first device according to the invention, i.e. the horizontal single-shaft crusher an almost smooth process of the shredding process. There is a separation from Hard parts and chips instead. A discharge of chips over the coarse part ejection element largely avoided. The downtimes become shorter and the wear and tear on the Shear elements reduced. The device works automatically as needed Labor force decreased. The device can be manufactured easily and inexpensively. It is possible to retrofit existing crusher accordingly or when manufacturing new crusher to largely use existing modules. So is as Coarse part ejection element e.g. a simple flap that can be opened to the outside is conceivable. It can also be a door that can be moved sideways.

It can be advantageous to design the first device according to the invention such that the negative accelerations of the shaft via the acquisition of measured values on the drive can be determined. The chip breaker drive is usually outside the Chip breaker arranged so that a measuring device housed there and dust-free easy to maintain.

It may be advantageous to design the first device according to the invention such that one of the Shear rows at the level of the shaft axis or lower, i.e. below the opening of the Coarse part ejection element, and the other row of shears is on the opposite wall is arranged above the shaft axis. Remains a component between the lower row of shears and hang on the shaft, a single reversal can loosen this component directly move to the opening in the wall, whereby it leaves the shredding room. At the on the opposite side, the row of scissors must be placed higher, so that a blocking Component that has to be transported to the coarse part ejection element, more easily via the Shaft can be transported.

Furthermore, it can be advantageous to design the first device according to the invention in such a way that that the lower shear row is the lower limit of the coarse part ejection element. With such an embodiment, a blocking component is already possible as soon as possible on the large part ejection element. A short reversal is sufficient to loosen this component and weed out immediately.

The first device according to the invention can advantageously be designed such that the Rows of scissors mounted on the walls with a slope to the coarse part ejection element are. Such a slope facilitates the transport of blocking when reversing Components to the coarse part ejection element and through this.

The aforementioned task is carried out in a second device for shredding chips, which with a arranged in a shredding room, by means of drive and control in both directions rotatable, with sheared, horizontal shaft and on one assigned countershear elements of the same type and a matching one perforated sieve bottom, which is curved to the shaft and the counter shaft, is solved in that at least one of the walls of the comminution chamber lying parallel to the shaft axis a large-part ejection element that can be opened is attached. Furthermore, the Speed of change in load on the driven shaft (s) a the negative Accelerations for at least one of the shafts detecting control for the Coarse part ejection element is provided, the controls of the shaft, countershaft and Coarse part ejection element are networked with each other; depending on the a variable number of reversing processes for each negative acceleration closed and / or open coarse part ejection element programmable.

The second device according to the invention, i.e. the horizontal twin-shaft crusher a smooth process of the shredding process. It takes place just like the first device according to the invention, i.e. with the single-shaft crusher, an almost pure separation of hard parts and chips, whereby a discharge of chips over the Coarse part ejection element is largely avoided. The downtimes become shorter and wear of the shear waves is reduced. This device also works automatically and can be manufactured easily and inexpensively. It is possible to use existing twin-shaft breakers to retrofit accordingly, or as far as possible already in the manufacture of new crushers access existing modules. One or two coarse part ejection elements e.g. in Form of flaps or sliding doors can be provided.

It may be advantageous to use the second device according to the invention, i.e. the Twin-shaft chip breakers to be designed in such a way that the negative accelerations at least one of the shafts can be determined by recording measured values on the drive. The drive A chip breaker is usually located outside the chip breaker, so there a measuring device can be housed dust-free and easily maintained.

It may be advantageous to use the second device according to the invention, i.e. the Two-shaft chip breaker to be designed in such a way that the shaft increases in relation to the counter shaft stored and a large part ejection element on the wall facing the counter shaft is appropriate. Due to the increased mounting of the shaft, the previously blocking Components rather from the lower counter shaft to the coarse part ejection element carried. This reduces the number of reversals required, and can also be reduced to one second coarse part ejection element can be dispensed with.

It may also be advantageous to use both devices according to the invention, i.e. the single-shaft or the twin-shaft crusher, in such a way that the device with a Tilt angle is set up around one or two axes. It can still be advantageous be that one or both inclination angles can be individually adjusted. At a Embodiment in which e.g. the axis of rotation of the slope parallel to the axis of rotation of the Waves are formed, the ejection of coarse parts by the inclined position Device for the large part ejection element can be significantly simplified.

Furthermore, it can be advantageous for both devices according to the invention which To attach shear elements and / or counter shear elements individually to the shaft. In the Shredding of chips leads to irregular wear of the (counter) Shearing elements. Some (counter) shear elements wear out faster than others. This (Counter) shear elements can now be removed and replaced individually.

It can also be advantageous for both devices according to the invention, the shear elements and / or to form counter shear elements differently on a shaft. So a wave or both shafts can be equipped with differently sharp (counter) shear elements. The sharper (counter) shear elements can be used in areas with greater stress be arranged. With an arrangement with a slightly inclined shaft axis in the direction of gravity is it e.g. sensible, increasing from the higher shaft end to the lower shaft end to attach sharper (counter) shear elements.

Advantageously, both devices with a drive in the form of an electric or Hydraulic motor to be equipped.

It can be advantageous for both devices insofar as they are provided with an electric motor are, to record the negative shaft acceleration a pickup for To provide speed measurement on the electric motor. It can be used as a pickup rotor-shaped signal disc with proximity switch. By capturing the negative Shaft acceleration via the change in speed of the drive means that there is no direct need Registration on the shaft, which would be difficult to implement.

Furthermore, it can be advantageous for both devices insofar as they have an electric motor are provided to measure the negative wave acceleration via the increase in current.

It can also be advantageous for both devices if they are provided with a hydraulic motor are the negative shaft acceleration via a volume flow or speed measurement to capture.

Furthermore, it can be advantageous to design the devices according to the invention in such a way that that the coarse part ejection element with a sensor for detecting passing coarse parts is equipped. This can be an optical sensor. A component happens the coarse part ejection element, the coarse part ejection element is closed immediately afterwards and the reversing process ends.

The devices according to the invention can advantageously be designed such that the Coarse part ejection element is a flap that can be opened by means of pneumatics or hydraulics. Such operated flaps are already known and proven from other areas. On Ejection element in the form of a flap is simple and inexpensive to manufacture. This Embodiment is also robust enough to withstand the daily stress Comminution process.

Advantageous embodiments or training forms of the method according to the invention or The horizontal single and double shaft breakers according to the invention are described below shown several figures.

Figur 1:

eine schematische Aufsicht auf einen Einwellenspänebrecher

Figur 2:

einen Schnitt B-B aus Figur 1 durch einen Einwellenspänebrecher mit geschlossenem Grobteilauswurfelement

Figur 3:

einen Schnitt B-B aus Figur 1 durch einen Einwellenspänebrecher mit geöffnetem Grobteilauswurfelement

Figur 4:

eine Aufsicht auf einen Zweiwellenspänebrecher mit geschlossenem Grobteilauswurfelement

Figur 5:

einen Schnitt durch einen Zweiwellenspänebrecher mit geschlossenem Grobteilauswurfelement und zwei auf gleichem Niveau angeordneten Wellen

Figur 6:

einen Schnitt durch einen Zweiwellenspänebrecher mit geschlossenem Grobteilauswurfelement und zwei auf unterschiedlichem Niveau angeordneten Wellen

Figur 7:

Ansicht eines geneigten Zweiwellenspänebrechers, wobei die Drehachse der Neigung parallel zu den Drehachse der Wellen ist

Figur 8:

Ansicht eines geneigten Zweiwellenspänebrechers wobei die Drehachse der Neigung normal zu den Drehachsen der Wellen verläuft

Figur 9:

eine schematische Aufsicht auf einen elektrischen Antrieb

It shows:

Figure 1:

a schematic plan view of a single-chip breaker

Figure 2:

2 shows a section BB from FIG. 1 through a single-shaft chip crusher with a closed coarse part ejection element

Figure 3:

2 shows a section BB from FIG. 1 through a single-shaft chip crusher with an open coarse part ejection element

Figure 4:

a top view of a twin-shaft chip crusher with a closed coarse part ejection element

Figure 5:

a section through a two-shaft chip breaker with a closed coarse part ejection element and two shafts arranged on the same level

Figure 6:

a section through a two-shaft chip breaker with a closed coarse part ejection element and two shafts arranged at different levels

Figure 7:

View of an inclined two-shaft chip breaker, the axis of rotation of the inclination being parallel to the axis of rotation of the shafts

Figure 8:

View of an inclined two-shaft chip breaker with the axis of rotation of the inclination normal to the axes of rotation of the shafts

Figure 9:

a schematic plan view of an electric drive

FIG. 1 shows a single-shaft chip crusher with a comminution chamber 1 and one Ejection chamber 2 shown. A horizontal shear shaft 3 is in the comminution space 1 arranged with a plurality of shear elements 4, which are driven by an electric drive 5 is driven and is provided with a controller, not shown here. One of the Shear elements 4 are detailed, the others are shown schematically. The shear elements 4 are individually in rows mostly parallel to the shear shaft axis at a distance from each other the shear shaft 3 screwed. Each shear element 4 can have one or more Shear knives of various designs. In the present one Execution, the shear element 4 is formed in one piece with a single shear knife 6.

The shear knife 6 was milled into the shear element. The cutter 6 lies predominantly across the shear shaft axis.

On the wall 7 is a counter shear element in the form of a shear row 8 with shear teeth 9 screwed. This shear row 8 is above the shear shaft axis with an inclination to Shear shaft axis aligned. On the opposite wall 10, which in the figures 2 and 3, there is another row of shears 11 at the level of the shear shaft axis screwed. It forms the lower limit of a foldable outward Coarse part ejection element in the form of an ejection flap 12. This shear row 11 is for Ejection chamber 2 attached with a downward slope. When turning the shear shaft 3 the shear blades 6 of the shear shaft 3 engage between the shear teeth 9 of the two shear rows 8.11. The shear teeth within a row of shears can be designed differently. she can e.g. vary in shape, hardness and sharpness. Depending on how suitable the shear knife 6 in the areas engaging between the shear teeth 9 take the place of a sheared one Stressing the chips a cutting stress.

The ejection flap 12 can be opened towards the ejection chamber 2 via a lever device 13 become. It is closed during the normal shredding process. Not here shown control of the ejection flap 12 is networked with the control of the shear shaft 3. Not shown here is a concave arch arranged below the shear shaft 3 Perforated sieve plate 14. This perforated sieve plate 14 can be seen in FIGS. 2 and 3.

If chips are to be shredded from above, e.g. metallic shavings, in the Given crushing space 1, these are gripped by the rotating shear shaft 3, moved to the shear row 8, between the shear elements 4 of the shear shaft 3 and the shear row 8 crushed and carried to the perforated screen bottom 14. The chips that are already small enough fall through the perforated screen bottom 14. Larger chips are between shear shaft 3 and Perforated screen tray 14 is sheared and partially discharged through perforated screen tray 14 or taken away by the shear shaft 3. Between the shear row 11 and the shear shaft 3 the chips taken away are shredded again and back to the starting point transported. There, these chips meet new, still uncrushed chips and become part of it this again transported to the first row of shears 8 and again crushed.

It often happens that the chips to be shredded are mixed with coarse particles. The skill e.g. Be fragments of machined workpieces. Now such a part gets into the shredding chamber 1 between the shear shaft 3 and the shear row 8, the shear shaft 3 blocked immediately. Compressed tufts of chips can also block the shear shaft 3 cause, however, the generated negative acceleration of the shear shaft 3 is less than for large parts.

The negative acceleration of the shear shaft 3 is e.g. about Speed measurements on the electric drive 5 detected. The device parts for Speed measurement are shown in Fig. 9. Depending on the strength of the negative acceleration and in Depending on the chip type, size and quantity, a programmed reversing and Ejection program. The speed of rotation of the shear shaft 3 when reversing significantly reduced compared to the normal rotational speed.

For blockages due to dense tufts of chips, for example, a reversing process of 20 Reversing steps set with the chute 12 closed. That number should be selected high enough so that the compacted tufts of chips are still crushed can be. If the specified number of reversing steps is exceeded, the Ejection flap 12 opened and a possibly still existing uncrushed component over the again reversing shear shaft 3 are carried away.

In the case of hard coarse parts, which in the case of blockages result in a high negative acceleration of the shear shaft 3 will cause a short, e.g. 3-4 times reversing of the shear shaft 3 with open Ejection flap 12 performed. The coarse part can then be sorted out immediately. Then the ejection flap 12 is closed again and the shear shaft 3 takes its normal direction and speed of rotation.

FIGS. 2 and 3 each show a section B-B through the single-shaft chip breaker from FIG. 1 shown with the chute 12 open and with the chute open. On the shear shaft 3 are with constant spacing, shear elements 4, each fitted with a shear knife 6. These shearing knives can be of different sharpness. On both sides of the A shear row 8, 11 is screwed into each shear shaft 3. The shear teeth 9 of the shear rows 8, 11 reach between the shear blades 6 of the shear shaft 3. The shear teeth 9 can be within one Shear row 8, 11 can be of different sharpness. Below the shear shaft 3 is a concave arched perforated screen bottom 14 is arranged. The deeper shear row 11 forms the lower limit of the chute 12. This chute 12 can be hydraulic or pneumatically by means of a lever device 13 (not shown here) into an ejection space 2 be folded in and thus gives a passage in the comminution chamber wall 10 free.

In Figures 4 and 5 are a top view and a section through Twin-shaft chip crusher with a comminution chamber 15 and an ejection chamber 16 shown. A shear shaft 17 and a counter shear shaft 18 are in the comminution chamber 15 arranged horizontally at the same level. The waves 17, 18 are with a variety Shear elements 19, 19 'in the form of shear washers. The shaving discs can can be different in sharpness, hardness and shape. These shear disks 19,19 ' are lined up on the respective shaft 17, 18 at a distance such that the shear plates 19 of the Shear shaft 17 into the spaces between the shear washers 19 'of the counter shear shaft 18 can intervene. The outer edge of each shear disk 19, 19 'is at least one Provide shear tooth 20 or the like.

A perforated screen 21 is arranged below the two shafts 17, 18. This consists of one too the underside of the shaft with a double concave arched perforated bottom 22, a central web 23, 2 side walls 24.25 and stiffeners. These individual parts are via weld seams 26, 27 connected to each other in one piece. The perforated screen 21 is on its side walls 24, 25 with the Screwed walls 28, 29 of the comminution chamber 15.

The shafts 17, 18 are driven by an electric drive 30 and have at least one a controller, not shown here. On the wall 28 is a first Perforated side wall 24 attached such that its top surface 31 above the shaft axes lies. On the opposite wall 29, which the crushing chamber 15 from the Separates ejection chamber 16, there is a closed ejection flap 32. The lower Limitation of the ejection, which is formed by a head surface 33 of the wall 29 is with inclined towards the ejection chamber 16. The to the crushing room 15 facing edge of this head surface 33, i.e. the higher edge of the head surface 33 is located at the level of the shaft axes. The ejection flap 32 can be pneumatically or hydraulically a lever device 34 can be opened towards the ejection chamber 16. It is during the normal shredding process closed. As with the single-shaft chip crusher described, is also the control of the ejection flap 32 with the two-shaft chip crusher Control of the shear shaft 17 networked. Both controls are not shown here. It is also possibly another controller, i.e. a control of the counter shear shaft 18 too network.

If chips are to be shredded from above, e.g. metallic shavings, in the Given crushing space 15, these will be the shear discs 19,19 'of the two themselves rotating shafts, i.e. the shear shaft 17 and the counter shear shaft 18, between crushed and carried to the perforated screen bottom 22. It depends on the arrangement the shear discs 19, 19 'between them to form a shearing or cutting Stress on the chips. In general, the shear disks 19, 19 'are arranged such that a cutting stress on the chips. The chips, which are already small enough, fall directly through the perforated screen bottom 22. Too large chips are between the Shear discs 19, 19 'of the respective shaft 17, 18 and the perforated sieve bottom 22 shearing claimed and partially carried out via the perforated screen bottom 22 or by the shafts 17, 18 taken and transported back to the starting point of the shredding. This The chips that are taken along with the new chips are again rotated the waves 17, 18 crushed.

If a large part now gets between the two shafts 17, 18 in the comminution chamber 15, it can there is a blockage of waves 17, 18. Coarse particles can be both hard fragments and also be compacted tufts of chips. The negative acceleration of the shear shaft 17 and / or the Counter shear shaft 18 is e.g. detected by speed measurements on the electric drive 30. The Device parts for speed measurement are shown in Fig. 9. Depending on the strength of the negative Acceleration and depending on the type, size and amount of chips begins programmed reversing and ejection program. Both the Schenvelle, the is further away from the ejection flap 32 (here: shear shaft 17) as well as the other shaft (here: counter shear wave 18). Of course, the shear shaft 17 could be closer to the Ejection flap and the counter shear shaft 18 may be arranged further away. They are Reversing the two shafts 17, 18 to be coordinated so that the coarse parts to be discharged are transported to the discharge flap 32 as quickly as possible. It can be provided that one of the two shafts or both shafts 17, 18 during this Program runs their rotation speed compared to the normal rotation speed significantly reduce.

Now there is a hard, coarse fragment between the wall 28 and the shear shaft 17, so the short, e.g. Reversing the fragment 5-6 times back and forth Shear shaft 17 detected and transported to the counter shear shaft 18. to To facilitate this transport process, the first perforated screen side wall 24 is on the wall 28 attached with a head surface 31 above the shear shaft and counter shear shaft axis. The Large part transported to the counter shear shaft 18 is now gripped by it and through Reverse to the discharge flap 32 promoted. The coarse part falls into this through the ejection flap 32 the ejection chamber 16. Then the ejection flap 32 is closed again and the Shafts 17, 18 resume their normal direction and speed of rotation.

For blockages due to dense tufts of chips, for example, a reversing process of 20 Reversing steps set with the ejection flap 32 closed. That number should be chosen high enough so that compacted tufts of chips are still crushed can. If the specified number of reversing steps is exceeded, the Ejection flap 32 opened and a possibly still existing uncrushed component over the again reversing waves 17, 18 are carried away.

In a further possible embodiment of a twin-shaft chip breaker according to FIG. 4 and 5, which is not explicitly shown here, it is provided that on the ejection flap 32 opposite wall 28 a further discharge flap is attached; here is the first Form perforated screen side wall 24 shortened accordingly. By such Embodiment can rough parts by transporting only one of the shafts 17 or 18th be carried out. Precise coordination of the reversing movements of the two shafts can therefore be dispensed with.

FIG. 6 shows an embodiment which is slightly modified compared to FIGS. 4 and 5 of the twin-shaft chip breaker according to the invention. Here is the shear wave from the Ejection flap 32 is further away (here: shear shaft 17) higher than that Counter shear shaft 18. Such an increased arrangement of the shear shaft 17 facilitates the Transport of a large part to the ejection chamber 16.

FIGS. 7 and 8 show a twin-shaft chip crusher according to the invention in an inclined position Shape. Here, the axis of rotation of the inclination is once parallel and once normal to the Axes of rotation of the shafts 17, 18 are formed. With an inclination by an angle α to Coarse part ejection chamber 16 is the discharge of coarse parts or compacted tufts of chips facilitated by the ejection flap 32. By tilting the device by an angle β The material to be shredded becomes towards the ends of the shafts lying close to the drive 30 moved to the lower ends of the shafts 17, 18. There, shear washers 19, 19 Higher sharpness can be provided, especially the tufts of chips that are difficult to shred can chop. Of course, both inclinations can be combined and varied in their extent become. Such an inclined structure is also conceivable for single-shaft chip breakers.

FIG. 9 shows an electric drive 5 or 30 on its motor shaft 35, a flat rotor 36 is appropriate. This rotor 36 has a plurality of rotor teeth 37 on its outer edge on, which are arranged at an equal distance from each other. The rotor 36 is in the figure not shown continuously. A light metal fan 38 is indicated above the rotor 36. Below the rotor teeth 37 is a proximity switch in the form of a signal sensor 39 a bracket 40 statically attached. This signal pickup 39 can be an optical sensor.

If the motor shaft 35 rotates, the rotor 36 is also moved. The signal pickup 39 detects the number of rotor teeth 37 moving past it. The one not shown here Controls of the shear shaft (s) 3 or 17, 18 and ejection flap (s) 12 or 32 are controlled by the Signal sensor 39 transmits the respective negative accelerations of the motor shaft 35, so that, depending on the acceleration category, a defined program runs that Reversing operations and possibly opening the ejection flap (s) 12 and 32 includes.

reference numeral

1.

shredding chamber

Second

ejection chamber

Third

shear wave

4th

shear element

5th

Electric drive

6th

razor

7th

wall

8th.

Higher series of shears

9th

shearing teeth

10th

Wall with ejection flap

11th

Lower row of shears

12th

discharge flap

13th

lever device

14th

Lochsiebboden

15th

shredding chamber

16th

ejection chamber

17th

shear wave

18th

Against shear wave

19th

Shear disc on shear shaft 17

19. '

Shear plate on counter shear shaft 18

20th

shearing teeth

21st

strainer

22nd

Lochsiebboden

23rd

center web

24th

1. perforated screen side wall

25th

2nd perforated screen side wall

26th

Weld

27th

Weld

28th

wall

29th

Wall under the chute

30th

Electric drive

31st

Top surface of the 1st perforated screen side wall 24

32nd

discharge flap

33rd

Top surface of the wall 29

34th

lever device

35th

motor shaft

36th

Rotor (rotor-shaped signal disc)

37th

rotor teeth

38th

Light metal fan

39th

Signal sensor (proximity switch)

40th

bracket

Claims (26)

1. Method for comminuting chips in a comminuting space between a driven horizontal shaft, which can be rotated in both directions and is fitted with shearing elements, and assigned counter-shearing elements, with chips introduced from above being comminuted and discharged downwards via a perforated screening plate and blocking constituents, which cause the shaft to come to a standstill, being segregated after reversing the shaft,
   characterized in that the rate of change of the loading of the driven shaft, fitted with shearing elements, is sensed,
   in that the presence of blocking constituents is established on the basis of the sensed rate of change of the loading while taking into account the type, quantity and/or size of chip, and
   in that then the non-comminuted blocking constituents are ejected after one or more reversals of the shaft.
2. Method for comminuting chips in a comminuting space according to Claim 1, characterized in that the acceleration of the shaft is sensed to sense the rate of change of the loading of the driven shaft fitted with shearing elements.
3. Method according to Claim 2, characterized in that, on the basis of the established acceleration profile, the constituents causing a blockage are subdivided into at least two categories, the constituents being moved more or less frequently by reversing of the shaft, and either passed on in a comminuted state or thrown back in an uncomminuted state, according to the relevant category.
4. Method according to Claim 3, characterized in that the categories are arranged according to increasing negative acceleration and the frequency of reversal decreases from category to category with increasing negative acceleration.
5. Method according to one of Claims 2 to 4, characterized in that the change in rotational speed of the drive is measured for sensing a negative shaft acceleration.
6. Method according to one of Claims 1 to 5, characterized in that the rotational speed is set to be lower during the reversing of the shaft than the normal rotational speed.
7. Apparatus for carrying out the method according to one of the preceding claims for comminuting chips in a comminuting space (1) with a horizontal shaft (3) which can be rotated in both directions by means of a drive (5) and controller and is fitted with shearing elements (4), with counter-shearing elements (8, 11) assigned to this shaft (3) and with a curved perforated screening plate (14) adapted to the shape of the shaft,
   characterized in that an openable coarse-part ejecting element (12) is attached to the walls (7, 10) of the comminuting space (1) lying parallel to the shaft axis,
   in that the counter-shearing elements (8, 11) are arranged in two rows on walls (7, 10) of the comminuting space (1) lying parallel to the shaft axis,
   in that a controller for the coarse-part ejecting element (12) is provided,
   in that the controllers of the shaft (3) and coarse-part ejecting element (12) are linked with each other,
   in that, for sensing the rate of change of the loading of the shaft (3), a controller for the coarse-part ejecting element (12) is provided, sensing the negative accelerations of the shaft (3), and
   in that, depending on the respective negative acceleration, a variable number of reversing operations with the coarse-part ejecting element (12) closed and/or open can be programmed.
8. Apparatus according to Claim 7, characterized in that the negative accelerations of the shaft can be determined by sensing measured values at the drive (5).
9. Apparatus according to Claim 7 or 8, characterized in that one of the shearing rows (11) lies at the height of the shaft axis or lower, i.e. underneath the opening of the coarse-part ejecting element (12), and the other shearing row (8) is arranged on the opposite wall (7) above the shaft axis.
10. Apparatus according to Claim 9, characterized in that the lower-lying shearing row (11) is the lower limitation of the coarse-part ejecting element (12).
11. Apparatus according to one of Claims 7 to 10, characterized in that the shearing rows (8, 11) are mounted on the walls (7, 10) with a slope towards the coarse-part ejecting element (12).
12. Apparatus for carrying out the method according to one of Claims 1 to 6 for comminuting chips in a comminuting space (15) with a horizontal shaft (17) which can be rotated in both directions by means of a drive (30) and controller and is fitted with shearing elements (19), and with counter-shearing elements (19') arranged on an assigned countershaft (18) of the same kind and with a perforated screening plate (22) curved to match the shaft (17) and countershaft (18),
    characterized in that an openable coarse-part ejecting element (32) is attached to at least one of the walls (28, 29) of the comminuting space (15) lying parallel to the shaft axis,
    in that a controller for the coarse-part ejecting element (32), sensing the negative accelerations of at least one of the shafts (17, 18), is provided for sensing the rate of change of the loading of the driven shaft(s) (17, 18),
    in that the controllers of the shaft (17), countershaft (18) and coarse-part ejecting element (32) are linked with each other, and
    in that, depending on the respective negative acceleration, a variable number of reversing operations with the coarse-part ejecting element (32) closed and/or open can be programmed.
13. Apparatus according to Claim 12, characterized in that the negative accelerations of at least one of the shafts can be determined by sensing measured values at the drive (30).
14. Apparatus according to Claim 12 or 13, characterized in that the shaft (17) is mounted at a higher level than the countershaft (18) and a coarse-part ejecting element (32) is attached on the wall facing the countershaft (18).
15. Apparatus according to one of Claims 7 to 14, characterized in that the apparatus is to be set up with an angle of inclination about one or two axes.
16. Apparatus according to Claim 15, characterized in that the one angle of inclination or both angles of inclination can be individually set.
17. Apparatus according to one of Claims 7 to 16, characterized in that the shearing elements (4; 19) and/or counter-shearing elements (19') can be fastened individually on the shaft (3; 17, 18).
18. Apparatus according to one of Claims 7 to 17, characterized in that the shearing elements (4; 19) and/or counter-shearing elements (19') on a shaft (3; 17, 18) are formed differently.
19. Apparatus according to one of Claims 7 to 18, characterized in that an electric motor or hydraulic motor is provided as the drive (5; 30).
20. Apparatus according to Claim 19, characterized in that a pulse pickup for measuring the rotational speed at an electric motor (5; 30) is provided for sensing the negative shaft acceleration.
21. Apparatus according to Claim 20, characterized in that the pulse pickup is a signal disc (36), in the form of a rotor, with a proximity switch (39).
22. Apparatus according to Claim 19, characterized in that the increase in current at an electric motor (5; 30) is to be measured for sensing the negative shaft acceleration.
23. Apparatus according to Claim 19, characterized in that a volumetric flow measurement or rotational speed measurement at a hydraulic motor is provided for sensing the negative shaft acceleration.
24. Apparatus according to one of Claims 7 to 23, characterized in that the coarse-part ejecting element (12; 32) is equipped with a sensor for sensing passing coarse parts.
25. Apparatus according to Claim 24, characterized in that the sensor is an optical sensor.
26. Apparatus according to one of Claims 7 to 25, characterized in that the coarse-part ejecting element is a flap which can be opened by means of pneumatics or hydraulics.

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