Material grinder with grinding device, grinding device and maintenance method

Abstract

The invention relates to a material pulverizer (1), in particular for pulverizing cut recoverable material, comprising a rotatably mounted rotor, referred to as a cutting head (10), on which a plurality of axially extending cutting blades (11) are arranged, which are spaced apart from one another in the circumferential direction and have radially outer cutting edges (12) forming a cutting circumference, the invention relates to a material grinder (1) comprising a rotor housing, referred to as a stator (20), which substantially surrounds a cutting head (10), the stator (20) and the cutting head (10) defining a cutting chamber (3) arranged between the stator (20) and the cutting head (10), the cutting blade (11) and at least one counter blade (23) arranged on the inner circumference of the stator (20) protrude into the cutting chamber (3), where the counter blade (23) is arranged radially spaced from the cutting circumference to form a cutting gap (4), and where the stator (20) has at least one outlet (22), a screen (24) delimiting the cutting chamber (3) is arranged in the outlet (22). According to the invention, the material grinder (1) has a grinding device (30) which has a grinding device receptacle (31) which holds grinding elements, the grinding device (30) being arranged outside the cutting circumference and the grinding elements and the screen (24) being movable in terms of their position, the cutting circumference is arranged such that the respective radial spacing from the cutting circumference can be adjusted as desired. The invention also relates to a comminuting device (100) having the material comminuting machine (1) and a maintenance method.

Description

[0001] The present invention relates to a material grinder according to the features of the preamble of claim 1, which is designated for grinding material to be cut, in particular (recyclable) material to be cut, such as waste, (fiber-containing) plastic material or the like. The material to be cut or the material to be ground may contain interfering substances, such as silica-containing substances or the like. In addition, when the material to be cut is fed into the material grinder, its orientation is uneven.

[0002] Universal grinders, in particular granulators or similar devices, have long been known. Such grinders always have a vertically or horizontally rotatably driven cutting head, where the term "cutting head" here collectively refers to a rotor in the form of a drum, roller or similar form, or a rotor with one or more rotor blades. Usually, a plurality of grinding tools, in particular cutting blades, are arranged on the cutting head, and when the cutting head rotates, the cutting edges of the cutting blades form a cutting circumference. In the cutting area, i.e., on the outer periphery of the cutting circumference, the cutting blades may comprise different materials, such as tungsten carbide or the like.

[0003] The cutting head is at least partially surrounded by a rotor housing, which is herein referred to as a stator. The stator surrounds the rotatably mounted cutting head, and a static counter blade or preferably a plurality of static counter blades are arranged on the inner circumference of the stator. The stator is usually designed as a housing that is at least partially cylindrical, which defines a space surrounding the rotor, also known as a cutting chamber. The material to be cut is ground in a cutting gap formed as the radial spacing between the cutting edge and the counter blade.

[0004] The material to be cut can be introduced into the cutting chamber through an inlet in the stator, and the ground material can be discharged from the cutting chamber through an outlet in the stator (due to centrifugal force). There are known conveying devices that force the material to be cut to be actively fed, i.e., to partially push the material to be cut into the cutting circumference.

[0005] In a particularly simple embodiment, the inlet can be the same as the outlet. Conveying devices and / or collecting devices adjacent to the outlet can be provided so that the ground material can be conveyed or collected respectively. A (perforated) screen arranged in the outlet and dimensionally defining the cutting space is used to determine the usually fine particle size of the ground material discharged from the cutting chamber, such that the material to be cut is ground until it passes through the screen. In particular, screens with a maximum size of about 100 mm are widely used. The screen acts together with the counter blade such that the material to be cut is cut several times to some extent, and during this process, the material to be cut is substantially not subjected to any defined orientation in the cutting chamber.

[0006] During comminution, the cutting blades and counter blades of a material comminutor are subject to various stresses, especially when there are deposits of silicon dioxide or the like on the material to be cut. The edge radius of the blade, i.e., the radius on the cutting edge formed by two converging surfaces of the blade, which is decisive for comminution, increases as wear progresses, whereby, for example, the required comminution force increases accordingly. Wear on the cutting edge also results in an increase in the cutting gap. This leads to a decrease in the cutting quality or cutting consistency because the material to be cut is increasingly flattened and / or torn, whereby the content of unwanted dust with a very small particle size in the material to be cut increases accordingly.

[0007] In order to be able to ensure sufficient uniform cutting consistency while using a moderate energy input and in order to be able to reliably convey the material to be cut through the sieve, it is necessary on the one hand to regularly resharpen the cutting blades and, optionally, also the counter blades, i.e., to reduce the cutting edge radius. On the other hand, it is particularly necessary to readjust the counter blades so that the cutting gap can be kept essentially constant in the context of sufficient cutting consistency.

[0008] DE 865 249B discloses a general material comminutor in which, in order to improve the cutting consistency, it is proposed to arrange the cutting blades and counter blades at an angle to the axis of rotation and at an angle to each other so that the comminution of the material to be cut can be achieved in a tangential cutting manner, in the manner of scissors. Accordingly, the helical design of the cutting blades according to the invention is said to be problematic with regard to the resharpening of the cutting blades. Now, it is common practice to arrange the blades in such a way that the material to be cut is comminuted by tangential cutting, thereby reducing the stress on the blades or respectively extending the service life cycle. It is also well known to provide a particularly hard surface or the like for the cutting edge in order to be able to extend the service life cycle.

[0009] However, ultimately, the common problem with known material comminutors is that resharpening the cutting blades and / or counter blades is associated with an economically disadvantageous material comminutor because the blades have to be disassembled in order to be able to grind them, which is time-consuming, labor-intensive and error-prone. Any downtime is particularly disadvantageous because a material comminutor is usually a central device within a larger processing unit, so that the entire processing unit is non-productive during the maintenance of the material comminutor. During the process of disassembling and installing the blades, it is also necessary to carefully clean the blade holders for releasably fixing the blades so that no residues are left, otherwise the fixed blades may crack or break due to uneven force fit when clamping the blades, or increased stress may act on parts of the cutting edge during the cutting process.

[0010] The present invention is based on the following object: to provide a material crusher that can operate in an economically advantageous manner and has a longer service life cycle, without compromising the cutting consistency, i.e., the cutting quality, or requiring a higher energy input for crushing the material to be cut, in particular recyclable waste, (fiber-containing) plastic materials or the like.

[0011] This object is achieved by a material crusher according to the features of claim 1, a crushing device according to the features of claim 15, and a method according to the features of claim 18.

[0012] The features of the device will be described below. These design features can be implemented in combination with the present invention, or they can be inventive in themselves independently of the present invention, and they can be implemented individually and independently of each other, or in any arbitrary combination, including implementing all the features mentioned, unless the combination is excluded by the expression or due to technical incompatibility.

[0013] In other words, the present invention provides a device for crushing the material to be cut or the material to be ground, specifically a material crusher. Related to the present invention is a grinding device that enables the grinding of the cutting blades, in particular the cutting edges, on the cutting head during the rotation of the cutting head, so that the long downtime of the material crusher can be economically advantageously avoided, because a high cutting consistency, i.e., a high cutting quality, can be ensured even without disassembling the cutting blades. In addition, the risk of blade failure is also reduced, because the clamping of the blade after grinding is not always performed manually. Furthermore, by rotating during grinding, an ideally geometric, substantially cylindrical cutting circumference can be achieved, such that the cutting edges of multiple cutting blades are each arranged along the circumference on the same circular path.

[0014] According to this proposal, the grinding device is arranged outside the cutting circumference, preferably radially outside the cutting circumference, by means of a grinding member holder that holds the grinding member. The grinding member holder can have a grinding disc, a grinding member support or the like, which are connected to the grinding member, wherein the grinding member is particularly preferably releasably connected to the grinding member holder, for example by an adhesive connection, a bonding connection, a latch connection or an insertion connection or the like, so that the grinding member can be relatively easily replaced when the grinding member wears. According to the present invention, the position of the grinding member is movable, so that it can selectively move from a stationary position without a grinding effect (where the grinding member is arranged outside the cutting circumference) to a closer grinding position with a grinding effect (where the grinding member engages with the cutting edge of the cutting blade), and preferably results in a substantially tangential chamfering of the cutting edge towards the cutting circumference, thereby dressing the cutting blade.

[0015] A screen that can occupy most of the circumferential part of the stator, and according to the present invention, its position is also movable, so that the size of the cutting chamber and thus the distance between the cutting circumference and the screen is variable. As the material removal amount increases during the resharpening of the cutting blade, the distance between the screen and the cutting circumference will basically increase. This is somewhat problematic in that if the material to be cut can pass through the screen, the cutting blade is also used to force the material to be cut through the screen. As the distance between the screen and the cutting circumference increases, the material to be cut is increasingly squeezed, and the energy required to drive the cutting head increases. By the movability of the screen position, these disadvantages can be surprisingly avoided, and the stress acting on the material to be cut can be reduced.

[0016] One or more position - movable screens can be provided. In addition, the screens can each be substantially integral or formed in segments so that a plurality of screen elements form a screen. The screen elements in the outlet can be aligned at an angle to each other. Optionally, the screen elements can be at least partially arcuate so that a plurality of screen elements achieve a greater arc.

[0017] In a design embodiment, the grinding device can have guides, for example in the form of guiding members, guiding channels or the like. Particularly preferably, a linear guide, which is advantageously aligned substantially parallel to the longitudinal axis or the rotational axis of the cutting head, and the grinding member holder is arranged on the linear guide so as to be displaceable along the cutting blade, specifically displaceable for grinding. For example, a grinding slider, a grinding carriage or the like can be arranged on the guiding member, which is mounted on running rollers and connects the grinding member holder to the linear guide in a displaceable manner. The linear guide with the grinding slider is used to be able to guide the grinding member reciprocally in a back - and - forth movement so as to effectively grind along the longitudinal axial range of the cutting blade. For example, due to the reciprocating grinding, scratches in the cutting edge of the cutting blade can be avoided. In addition, the cutting blade can be very evenly resharpened to produce a cutting circumference that is uniform along the length of the cutting blade. The area where the grinding member engages with the cutting blade is herein called the grinding area.

[0018] The grinding slider, the grinding carriage or the like is advantageously driven mechanically, hydraulically, pneumatically or electrically, for example by a chain - belt drive, a traction - rope drive or the like.

[0019] In a very simple design embodiment, the grinding elements can be held rotatably together in a grinding element holder in a grinding element receptacle. In a preferred refinement, the grinding element holder can hold the grinding elements rotatably such that the grinding elements can preferably rotate about an axis of rotation that is substantially perpendicular to the cutting head axis of rotation. The grinding element holder can be designed, for example, in the manner of a cup wheel. Here, the grinding elements can be arranged in cross-section and rotationally driven by the grinding element holder such that the grinding elements rotate in the direction of rotation of the cutting head and / or against the direction of rotation of the cutting head during the reciprocating movement. The rotational speed of the grinding elements is preferably slower than the rotational speed of the cutting head.

[0020] As an alternative to the cup wheel, the grinding element receiving device can have a rotationally driven grinding element wheel that is substantially aligned parallel to the cutting head axis of rotation and has the grinding elements arranged at least on its circumference such that the grinding elements can rotate in the same or opposite direction as the rotation of the cutting head.

[0021] The rotation of the grinding elements can each involve one complete rotation or multiple complete rotations about a single axis of rotation, and during this rotation of the grinding elements, the cutting blade is sharpened. It can also be provided that the grinding elements each rotate discontinuously about an arc such that the cutting blade is ground at least temporarily by non-rotating grinding elements. Here, partial rotations of 3° to 270°, particularly preferably 5° to 30°, are advantageous. Any (partial) rotation of the grinding elements is hereby referred to as rotation. It can further be provided that the grinding elements rotate outside and / or inside the grinding zone.

[0022] For a design embodiment of the positional mobility of the grinding elements, the grinding device can particularly advantageously have a grinding element actuator, specifically preferably on a linear guide, a grinding element receptacle, and / or a grinding element holder. During actuation, the grinding elements are selectively moved towards the cutting edge of the cutting blade or the radial spacing between the grinding elements and the cutting head is respectively reduced. To increase the effectiveness of the grinding elements, it may be sufficient to rotate the grinding elements so that these parts are closer to the cutting circumference or respectively engage with the cutting blade. The actuation for the grinding effect, i.e., the actuation when the grinding elements engage with the cutting circumference in the grinding zone, is hereby referred to as operational grinding or fine grinding, whereby grinding without actuation is referred to as rough grinding.

[0023] It can be provided that the grinding element actuation serves to move the grinding elements from a spaced-apart rest position to a grinding position with a grinding effect, and / or moreover can define the material removal intensity during grinding, wherein the actuation is preferably steplessly variable. For this purpose, the actuator can, for example, have one or more actuation screws by which the radial spacing can be adjusted. Optionally or additionally, it can be provided that there is a hydraulically or pneumatically driven cylinder or the like in order to actuate the grinding elements or respectively move the grinding elements to the rest position.

[0024] A particularly inventive improvement can relate to the nozzle unit on the grinding device. One or more preferably suction nozzles, suction ports or the like (collectively referred to herein as suction nozzles) are used to be able to directly discharge potential grinding dust from the grinding zone. For this purpose, the suction nozzles are aligned relative to the cutting circumference to generate a suction effect, meaning that the suction effect of the suction nozzles extends substantially to the cutting circumference. The nozzle unit is advantageously fluid-connected to a collection unit in which the grinding dust is collected. In this way, contamination of the material to be comminuted by grinding dust can be prevented. Optionally or additionally, application nozzles can be provided, for example, which feed a cooling fluid or the like to the cutting circumference.

[0025] In another design embodiment, the screen can be pivotally held, specifically preferably parallel to the axis of rotation of the cutting head, such that the screen can be pivoted out of the outlet in order to be able to expose the outlet, so that on the one hand the cutting head or the stator is easy to clean. On the other hand, the pivotal mounting can be such that the radial spacing of the screen from the cutting head and thus the dimensions of the cutting chamber can be selectively adjustable in a screen-actuated manner. This type of screen arrangement is advantageous in order to be able to ensure a substantially uniform spacing between the cutting circumference and the screen, so that an economically efficient energy input for driving the cutting head can be achieved and only a minimal influence is exerted on the material properties of the material to be cut, for example on the elastic-mechanical strength.

[0026] A screen support for adjusting the spacing and fixing the screen can be provided, which is pivotally mounted and has an adjusting device acting thereon, which is arranged outside the cutting chamber. Advantageously, the adjusting device can have an actuating pin, which is held substantially movably, preferably variably without steps in the radial direction, and which is connected to the screen support and defines the approach of the screen to the cutting circumference. Optionally or additionally, a pneumatically or hydraulically driven cylinder or the like can be provided, by means of which the pivot range of the screen support or the screen can be adjusted.

[0027] Generally, the screen can have a substantially rectangular shape, which is curved to correspond to the diameter of the cutting head or the stator respectively, wherein in this case the screen is pivotally held by the non-curved longitudinal sides. It can be provided that the screen has, on one end side, specifically on the opposite longitudinal sides, in the peripheral region of the screen (referred to herein as the transition region), a material thickness that tapers and decreases in cross-section, and the stator and the screen are arranged such that they at least partially overlap in the transition region, wherein the screen is arranged radially inside. The material thickness preferably decreases in the direction of rotation of the cutting head, so that the material to be cut does not undesirably get stuck in the cutting chamber or the like. The tapered overlap of the screen and the stator in the transition region facilitates the screen actuation adapted to the material removal caused by grinding.

[0028] An improved embodiment of the present invention may have a control unit which is connected in a signal - transmitting manner to the grinding device, in particular to the grinding element actuator, so that preferably the actuation degree can be adjusted by a program. Optionally or additionally, the control unit can feedback - control the reciprocating movement that guides the grinding element along the cutting blade. Advantageously, an operating element is linked to the control unit, by which the operator can define the actuation or the actuation program respectively. Optionally or additionally, a sensor for detecting the drive output of the cutting head or the like can be provided so as to be able to draw conclusions about the wear of the cutting blade therefrom and to be able to specifically initiate the re - grinding of the cutting edge in an automated manner. For this purpose, the control unit can preferably be designed to control the rotation of the cutting head.

[0029] In a particularly advantageous design embodiment of the present invention, the stator can have one or more punctiform and / or linear guiding elements outside the cutting circumference, in the form of projections, cams, guiding ribs, lips or the like, which project radially into the cutting chamber. The guiding elements can be used to align the material to be cut, in particular fragments of film, film strips or the like, during the rotation of the cutting head. Thus, among other things, the migration of the material D to be cut on the screen is reduced, and the cutting consistency and the discharge of the material to be cut from the cutting chamber are improved, so that the cutting edge of the cutting blade is subjected to less stress and thus the service life cycle of the material grinder can be extended. For a particularly advantageous design embodiment, it can be provided that the guiding elements are arranged on the screen.

[0030] An indicator for detecting the wear of the cutting edge can be the material to be cut once it has left the cutting chamber. In the case of severe wear, the material to be cut usually shows a fibrous, torn coating surface. In addition, the dust content, i.e., the content of relatively small particles of the material to be cut, also increases. Thus, in an improved embodiment, an optical detection of the material to be cut, for example a camera, can be provided, which detects substantial features such as the geometry, surface characteristics or the like of the material to be cut and preferably evaluates the features based on software. If the detected actual value deviates excessively from the stored target value, an alarm signal can be issued. For example, the alarm signal attracts the user's attention to the need for re - grinding. Optionally, the alarm signal can be transmitted to the control unit, which initiates the re - grinding in an automated manner.

[0031] Optionally or additionally, the dust content in the outlet flow can be detected electrically, for example by resistance measurement, or by a sieving method in which the dust content is first separated and then the weight of the dust content is determined. As already pointed out above, a sensor for detecting the power consumption of the drive unit of the cutting head can be provided, where an increase in the power consumption of the drive unit typically indicates severe wear of the cutting edge. In response to the determined or separately inferred cutting edge wear, a grinding process can be performed that is initiated by the user or, particularly preferably, automated by the control unit.

[0032] An acoustic sensor, for example in the form of a knock sensor, which is designated for detecting the sound of the relationship generated when the cutting blade moves past the opposing blade, can be particularly advantageous, where the dimensions of the cutting gap each generate a characteristic acoustic signal, which is typically or sensually perceivable as a knocking sound. In this way, conclusions about the cutting edge wear can be drawn in a simple manner and, if necessary, responded to by regrinding manually or in the automated manner as described above.

[0033] An acoustic sensor, in the form of a knock sensor or the like, can optionally or additionally particularly be used to determine the spacing of the grinding element from the cutting circumference. For example, this spacing can be important when activating the grinding element. If the actuation is carried out too quickly, or if the engagement of the grinding element in the cutting circumference is excessive, there is a risk of damaging the material crusher.

[0034] In one design embodiment, the material crusher can have a metal sensor that identifies metal components in the material to be cut. Advantageously, such components are detected before being fed into the cutting chamber in order to be able to prevent any damage, for example. For this purpose, the metal sensor can be connected to a control unit that stops feeding the material to be cut into the cutting chamber and / or stops the cutting head when a metal component is detected.

[0035] For cutting consistency, a substantial factor is, among other things, the size of the cutting gap between the cutting circumference and the opposing blade. Advantageously, a blade holder can be provided in which the opposing blade is releasably fixed to the stator, and in which the blade holder is movable relative to the cutting head so that the opposing blade can move closer to the cutting circumference, preferably in a steplessly variable manner. Particularly preferably, regardless of the improvement of the blade holder, the material crusher can currently have at least two opposing blades. Preferably, the blade holder can be adjusted in a motorized manner, for example by a linear motor with an adjustment spindle, where the drive is used for signal transmission and is preferably connected to a control unit for automatic adjustment of the cutting gap. Preferably, the opposing blade is held in the blade holder in a clamped manner, for example by a disc spring and / or hydraulic compression. In the context of extending the service life cycle, manual adjustment can thus be dispensed with. In particular, in order to be able to manually readjust the opposing blade, the blade holder can have an adjustment screw for defining the cutting gap.

[0036] In an improved embodiment of the present invention, the blade holders can each have a so-called blade seat for a plurality of opposing blades, where the opposing blades in the blade seat are preferably fixed by screws, and the blade holders are rotatably mounted such that the first blade seat with the opposing blade can be aligned in an operating position (creating a cutting gap) or a stationary position. In this way, the setup time can be significantly reduced by allowing the first opposing blade to work in the operating position while the second opposing blade of the blade holder can be maintained, in particular ground.

[0037] In a particularly advantageous design implementation, optionally or additionally to the nozzle unit, a suction device can be provided which is connected to the outlet and specifically has a suction flow effect so that the material to be cut can be suctioned from the cutting chamber through the screen into the outlet and ultimately, for example, into a collection device. The suction system supports the continuous removal of the material to be cut from the cutting chamber so that the material to be cut can be crushed with high cutting consistency and, for example, blockages or the like in the cutting chamber or the screen can be avoided.

[0038] In addition, a suction device may be advantageous during the grinding process in order to be able to suck up grinding dust, whereby, for example, when the cutting head rotates and the cutting blade is being ground but there is no material to be cut in the cutting chamber, contamination of the material to be cut can be avoided. In an improved embodiment, a suction device can be provided which sucks up the grinding dust directly from the grinding element. For this purpose, for example, a suction nozzle arranged on the grinding device can be provided, which is connected to the suction device with an effective suction flow. By arranging a filter or the like in the suction flow, separation of the grinding dust from the suction flow can be carried out, so that in principle the material to be cut can be comminuted during grinding without contaminating the material to be cut. This makes it economically advantageous to extend the service life cycle of the material crusher.

[0039] A particularly preferred embodiment having one or more of the features described herein relates to a material crusher in the form of a granulator. The granulator is particularly used to provide a particularly fine material fraction after cutting, i.e., advantageously having a maximum side length of substantially less than 100 mm, preferably substantially in the range of 20 to 100 mm, and particularly preferably substantially less than 20 mm.

[0040] It is further proposed to provide a waste comminution device which has a comminution device which is a material crusher, in particular a granulator, having the features according to this proposal and optionally having the features of the improvements or the like described previously. The proposed comminution device also has a feed device which transfers the material to be cut into the material crusher, for example in the form of a funnel arrangement or the like, with substantially no loss of the material to be cut. In addition, the comminution device can advantageously have a discharge device which conveys the comminuted material through the material crusher, for example by means of a conveying screw, a chute, an air stream or the like.

[0041] In a design embodiment, the comminution device can have at least one container for the material to be cut, into which the comminuted material to be cut is conveyed after passing through a sieve.

[0042] An improvement can advantageously provide a metering device arranged on the feed device in order to be able to introduce the material to be cut into the cutting chamber as required. First, this can prevent jamming or the like in the cutting chamber. Second, the feed of the material to be cut can be configured such that optimal utilization of the cutting head drive output can be achieved, for example by a uniform load situation. Third, a substantially uniform drive output can contribute to early detection of wear on the cutting blade and enable a response as required, for example by grinding. Fourth, a kind of buffer storage can be created by the metering device, especially when providing an intermittent feed of the material to be cut, for example by an industrial truck, a wheel loader or the like.

[0043] Advantageously, a conveying device can be provided which forms a conveying section opening into the feeding device. The material to be cut can be conveyed and fed as continuously as possible by the conveying device. In this context, the conveying device can also or in particular be used as a metering device for supplying the material to be cut on demand.

[0044] The invention also relates to a maintenance method for a material grinder, in particular for (re)establishing the operability of a material grinder, in which the grinding element is actuated towards the cutting edge of the cutting blade, the grinding element is guided along the cutting blade, and the sieve is actuated towards the cutting head, wherein the cutting head rotates at least during grinding. Preferably, the material grinder has one or more of the previously described features.

[0045] In the context of actuation, as described above, on the one hand, the grinding element is brought from a non-grinding arrangement into engagement with the cutting edge of the cutting blade, which cutting blade is axially extended on a rotatably mounted rotor of the material grinder called the cutting head. Once the grinding element is in engagement with the cutting edge, material can be removed from the cutting edge to reduce the cutting edge radius. On the other hand, the material removal can be defined by actuation such that with an increase in actuation, i.e., the grinding element is moved radially closer to the cutting head, a greater material removal is achieved, in particular at the cutting edge.

[0046] According to this proposal, the grinding element for the grinding effect is guided along the cutting blade, preferably in a reciprocating manner back and forth a plurality of times, wherein it is decisive that the cutting head rotates during this process. Since the cutting edge can be machined, i.e., ground, during the rotation of the cutting head, the service life cycle of the material grinder can be extended in an economically advantageous manner. It is no longer necessary to disassemble the cutting blade before grinding and then install the reground cutting blade in an expensive manner. In addition, the rotation during grinding achieves an ideally geometric, substantially cylindrical cutting circumference so that the cutting edges of a plurality of cutting blades are each arranged on the same circular path along the circumference.

[0047] According to this proposal, the spacing between the sieve and the cutting head or the cutting blade is reduced, wherein the sieve is arranged in the outlet of the stator. By reducing the spacing, it can be ensured that during grinding of the cutting blade, the material to be cut continues to be conveyed through the sieve, ensuring a constant cutting consistency. The actuation of the sieve can be carried out substantially simultaneously with the grinding process.

[0048] In an improved embodiment of the method, a radial actuation of one or more opposing blades can be provided, which are arranged on the inner circumference of the stator surrounding the cutting head, so that a substantially constant cutting gap between the opposing blades and the cutting edge can be achieved. Since material is removed from the cutting edge during grinding, it may be necessary to adjust the radial spacing between the opposing blade and the cutting blade or the cutting head respectively. The substantially constant cutting gap helps to extend the service life cycle of the cutting blade, thereby reducing maintenance costs and extending the service life cycle.

[0049] The present invention is based on the concept of presenting an economically advantageous solution. Extensive automation can make a significant contribution thereto. Thus, in a particularly inventive improvement, the process steps can be carried out in a feedback-controlled manner, i.e., coordinated with each other and particularly preferably automatically. In the control unit, a signal indicating increased cutting edge wear, i.e., the actual value deviates from the target value, is first evaluated. The power consumption of the cutting head and / or the cutting quality or the dust content or the like can be used as an indicator of increased cutting edge wear. If increased wear is detected, the control unit initiates the grinding of the cutting blade. For this purpose, the control unit controls the actuation of the grinding element and the guidance of the grinding element along the cutting blade. Once the desired cutting quality is reached again and / or after grinding the cutting blade according to known grinding experience, the grinding is paused. Thus, for example, a certain number of reciprocating movements and / or a specific grinding duration can be decisive. Since the grinding is carried out during the rotation of the cutting head, the rotational speed of the cutting head can be correspondingly feedback-controlled, so that the cutting grade or quality can be directly verified without the expensive installation and / or disassembly work of the cutting blade.

[0050] During grinding, it is particularly advantageous to suction the grinding dust. For this purpose, it can be provided that the control unit can feedback-control a suction device or the like. In addition, the control unit can initiate the application of a coolant or the like to cool the cutting blade during grinding.

[0051] Furthermore, it can preferably be provided that the control unit feedback-controls the actuation of the opposing blade according to the grinding intensity. For this purpose, the control unit can process a signal from which the material removal related to grinding can be inferred. On the other hand, it can be provided that the control unit processes a signal from which the spacing between the opposing blade and the cutting circumference can be inferred.

[0052] Optionally or additionally, the feedback control of the maintenance steps can follow a predetermined (time) interval, where each process step is particularly preferably feedback-controlled by the control unit.

[0053] Advantageously, it can be provided that the opposing blade is ground, particularly manually, before the actuation of the opposing blade occurs.

[0054] It is possible to set the method steps described above to be executed in sequence. It is also possible to set some or all of the method steps to be executed at least partially simultaneously. For example, the radial actuation of the grinding member (step a) can occur while grinding the cutting blade (step b). In addition, the radial screen actuation (step c) can occur while actuating the grinding member and / or while the grinding member is grinding the cutting blade. The counter blade actuation (step d) can start or be completed after steps a) to c) are completed or during one of steps a), b), or c).

[0055] Exemplary embodiments of the present invention will be explained in more detail below with reference to purely schematic diagrams, where individual features or combinations of features of the illustrated embodiments can also be implemented independently of the remaining embodiments of the respective embodiments in a proposed material grinder or in a comminution device respectively. In the drawings

[0056] FIG. 1 shows a cross-section of a first exemplary embodiment of a comminution device ( Figure 1a ), as well as a detailed illustration of fragmentation ( Figure 1b and Figure 1c );

[0057] Figure 2 shows a perspective view of the grinding device of the exemplary embodiment of FIG. 1 viewed obliquely from above;

[0058] Figure 3 shows a detailed perspective view of the grinding device of Figure 2 viewed obliquely from below;

[0059] Figure 4 shows a perspective view of the exemplary embodiment of FIG. 1;

[0060] Figure 5 shows a perspective view from obliquely above of another exemplary embodiment of an open comminution device;

[0061] Figure 6 shows Figure 5 a cross-section of the exemplary embodiment of; and

[0062] Figure 7 shows Figure 5 a cross-section of the exemplary embodiment of in a closed state.

[0063] FIG. 1 shows a cross-section of a first exemplary embodiment of a comminution device 100, which has a material comminutor 1 and a feed device 2. On the rotor shaft 15, a plurality of rotor blades 14 are arranged to form a rotor called a cutting head 10, which is horizontally aligned and rotatably mounted and is driven, for example, by an electric motor. The cutting head 10 surrounds a rotor housing designated as a stator 20, wherein the cutting head 10 and the stator 20 define a cutting chamber 3 therebetween, in which the material to be cut is comminuted. The stator 20 has an inlet 21 into which the funnel-shaped feed device 2 opens so that the material to be cut can be introduced into the cutting chamber 3. The stator 20 also has an outlet 22, in which a (perforated) screen 24, hereinafter referred to as the screen 24, is arranged, which only allows the material to be cut that has been sufficiently comminuted and can thus pass through the screen to pass through. The material to be cut coming out of the screen 24 enters a conveying device 5, which conveys the comminuted material for further processing (not shown in the figure). A maintenance flap 7 that can be selectively opened allows access to the cutting chamber 3.

[0064] Figure 1a The cutting head 10 in FIG. has a plurality of axially extending cutting blades 11 that are spaced apart from each other in the circumferential direction and have cutting edges 12 that form the radially outer part of the cutting circumference. A plurality of opposing blades 23 are arranged on the inner circumference of the stator 20, which project into the cutting chamber 3 and form a cutting gap 4 with a radial spacing from the cutting blades 11 ( Figure 1b ). As the wear of the cutting blades 11 increases on the cutting edges 12, or as the cutting edge radius increases, the cutting gap 4 increases (see also Figure 1c ).

[0065] Figure 1b The details of the grinding device 30 are particularly magnified. The grinding device has a bracket-shaped grinding element receptacle 31 and is arranged outside the cutting circumference of the cutting blades 11. The grinding element receptacle 31 is guided along a linear guide 32 (see also Figure 2 and Figure 4 ). The deflection wedge 6 particularly prevents large pieces of the material to be cut from being inadvertently jammed or wedged in the comminution device, thereby reducing the risk of malfunctions. By engaging the grinding pin 34 with the cutting edge 12, the cutting edge radius can be reduced.

[0066] The opposing blades 23 are connected to a linear motor with an adjustment spindle 36 so that their position can be moved ( Figure 1c ), so that the opposing blades 23 can be actuated in a substantially automated manner, specifically as a function of the material removal caused by grinding. In addition, in particular in Figure 1c a baffle 37 can be seen, which is open during the grinding of the cutting edge 12. Conversely, if no grinding process is provided to close the opening in the stator 20, the baffle 37 can be selectively closed to prevent any loss of the material to be cut.

[0067] Figure 1a The sieve 24 therein is arranged in the outlet 22, wherein the sieve 24 occupies most of the circumference of the stator 20 around the cutting head 10 and is fixedly arranged in the sieve support 25 in a positionally movable manner. The sieve support 25 is pivotable by a pivot mounting 26, wherein the pivot axis is aligned in the axial direction of the cutting head 10 so as to be able to adjust the radial spacing between the sieve 24 and the cutting head 10 or respectively the cutting circumference.

[0068] The adjusting device 40 acts on Figure 1a the sieve support 25 therein. The adjusting device has an actuating pin 41 which, in particular by means of a control dial, actuates the sieve 24 radially towards the cutting circumference such that the spacing between the sieve 24 and the cutting blade 11 or respectively the cutting circumference is adjustable. Thus, even with an increase in grinding-related material removal at the cutting edge 12, the spacing between the relevant cutting circumference and the sieve 24, which is relevant for cutting consistency and drive energy requirements, can be kept substantially constant and optimized, for example, as a function of the material to be cut.

[0069] Figure 2 Fig. shows a perspective view of the grinding device 30 of the exemplary embodiment of Fig. 1 as viewed obliquely from above. The grinding element receptacle 31 is held in a bracket-like manner along the linear guide 32 so that the grinding pin 34 can be guided along the cutting edge 12. The grinding element receptacle includes, among other things, a nozzle unit 35, wherein the application nozzle 35a is arranged above the grinding pin 34 and the suction nozzle 35b is arranged below the grinding pin 34. During grinding, a cooling fluid is applied through the application nozzle 35a. The suction nozzle 35b is used to be able to directly suction grinding dust to prevent contamination of the material to be cut.

[0070] Figure 3 Fig. shows a perspective detailed view of the grinding device 30 as viewed obliquely from below. Figure 2 The grinding pin 34 held in the grinding element support 33 can be seen. The toothed ring 38 on the circumference of the grinding element support 33 interacts with the spring clip 39 such that the grinding element support 33 allows the grinding pin 34 to rotate only in one direction and always rotates in a partial rotation manner by an arc measure that corresponds to the length of one tooth bottom or a multiple thereof. Each partial rotation causes an actuation of the grinding pin 34, i.e., moves the grinding pin 34 closer to the cutting circumference or respectively the cutting edge 12 of the cutting blade 11. Here, the actuation is preferably carried out by rotating the cutting head 10 in the grinding zone, which causes an operating grind.

[0071] Figure 4A perspective view of the fragments of the exemplary embodiment of FIG. 1 is shown. The linear guide 32 is fixedly mounted and aligned parallel to the longitudinal extension of the cutting blade 11. In a reciprocating motion indicated by double arrows in the figure, the grinding member holder 31 moves back and forth along the linear guide 32 and thus along the cutting blade 11 during the grinding operation, while the grinding pin 34 engages with the cutting edge 12.

[0072] Figure 5 Another exemplary embodiment of a particularly compact comminution device 100 solution is shown in perspective from obliquely above. In this example, the comminution device 100 is shown in the open state, i.e., in particular, two screens 24 are pivoted upwards and each expose an outlet 22, where only one outlet 22 is visible for illustration purposes (see also Figure 6 ). Contrary to the first exemplary embodiment, the cutting head 10 is now vertically aligned. The material to be cut is fed from above parallel to the axis of rotation of the cutting head by the feed device 2. Another difference is that instead of providing one screen, two screens 24 are provided, each pivotally held in a screen holder 25. Parallel to the axis of rotation of the cutting head 10, the linear guide 32 of the grinding device 30 is aligned.

[0073] In Figure 6 , Figure 5 the exemplary embodiment of

[0074] Figure 7 is shown in cross-section. The baffle 37 is shown open, so that the cutting edge 12 of the cutting blade 11 can be ground by the grinding pin 34. The feed cone 8 on the cutting head 10 causes the material to be cut to be guided outwards to the rotating cutting blade 11 among other things. The cutting blade 11 interacts with the opposed blade 23 and causes the material to be cut to be comminuted.

[0074] Figure 7 In Figure 5 and Figure 6 the exemplary embodiment of

[0075] is shown in cross-section in the closed state. On the one hand, the baffle 37 is shown closed, so that the grinding device 30 cannot be operated in this configuration. On the other hand, the screen 24 is shown closing the outlet 22. The cutting blade 11 of the cutting head 10 can also be seen, which together with the opposed blade 23 defines a cutting gap 4.

[0075] A maintenance method is explained below by way of example, especially for application in the case where the cutting blade 11 is severely worn.

[0076] In the process, the grinding member is actuated towards the cutting blade 11, i.e., the radial spacing between the grinding member and the grinding edge 12 is reduced until the grinding member contacts the grinding edge 12, so that the grinding member engages with the cutting circumference formed by the cutting edge 12 of the cutting blade 11. The degree of material removal on the cutting blade 11 is defined according to the further actuation of the grinding member after the first contact of the grinding member with the cutting edge 12.

[0077] Starting from before feeding or even during feeding, the grinding element is guided along the axial direction and arranged on the cutting head 10. The cutting blade 11 is ground, where the cutting edge 12 is preferably ground several times over the entire length of the cutting blade 11 in a reciprocating motion. It is crucial that the rotatably mounted cutting head 10 rotates during this process. The grinding element is preferably held in the cross-section of a cup-shaped wheel, where the cup-shaped wheel also rotates while the grinding element is reciprocally guided along the cutting edge 12 in a reciprocating motion.

[0078] In the context of an exemplary maintenance procedure, the screen 24 arranged in the outlet 22 of the stator 20 is also radially actuated by reducing the radial spacing between the screen 24 and the cutting blade 11.

[0079] After grinding the cutting blade 11 or already during this process, the counter blade 23 arranged on the inner circumference of the stator 20 is actuated by reducing the radial spacing between the cutting blade 11 and the counter blade 23, thereby setting a specific spacing called the cutting gap 4. If the counter blade 23 is also severely worn, the counter blade 23 is also ground before actuation. The operating steps of the maintenance method are feedback-controlled by a control unit, enabling optimized and substantially automated maintenance.

[0080] List of reference numerals:

[0081] 1 Material crusher

[0082] 2 Feed device

[0083] 3 Cutting chamber

[0084] 4 Cutting gap

[0085] 5 Conveying device

[0086] 6 Deflection wedge

[0087] 7 Maintenance baffle

[0088] 8 Feed cone

[0089] 10 Cutting head

[0090] 11 Cutting blade

[0091] 12 Cutting edge

[0092] 14 Rotor blade

[0093] 15 Rotor shaft

[0094] 20 Stator

[0095] 21 Inlet

[0096] 22 Outlet

[0097] 23 Opposed blades

[0098] 24 Screen

[0099] 25 Screen support

[0100] 26 Pivot mounting

[0101] 30 Grinding device

[0102] 31 Grinding member container

[0103] 32 Linear guide

[0104] 33 Grinding member support

[0105] 34 Grinding pin

[0106] 35 Nozzle unit

[0107] 35a Application nozzle

[0108] 35b Suction nozzle

[0109] 36 Linear motor with adjustment spindle

[0110] 37 Baffle

[0111] 38 Ring gear

[0112] 39 Spring clip

[0113] 40 Adjusting device

[0114] 41 Actuating pin

[0115] 100 Crushing equipment

Claims

1. A material shredder (1), in particular for shredding recyclable materials to be cut, The material shredder (1) has a rotatably mounted rotor known as a cutting head (10), On the cutting head (10), a plurality of axially extending cutting blades (11) are arranged, and the cutting blades (11) are spaced apart from each other in the circumferential direction and have cutting edges (12) forming the radial outer part of the cutting circumference, The material shredder (1) has a rotor housing known as a stator (20), and the rotor housing substantially surrounds the cutting head (10); Among them, The stator (20) and the cutting head (10) define a cutting chamber (3) arranged between the stator (20) and the cutting head (10), and the cutting blades (11) and at least one opposing blade (23) arranged on the inner circumference of the stator (20) project into the cutting chamber (3); Wherein, the opposing blade (23) is arranged to be radially spaced apart from the cutting circumference to form a cutting gap (4); and Wherein, the stator (20) has at least one outlet (22), and a screen (24) defining the cutting chamber (3) is arranged in the outlet (22), It is characterized in that The material shredder (1) has a grinding device (30), and the grinding device has a grinding device container (31) for holding grinding elements, Wherein, the grinding device (30) is arranged outside the cutting circumference; and The grinding elements and the screen (24) are movable in terms of their positions, so that the respective radial distances from the cutting circumference can be selectively adjusted.

2. The material shredder (1) according to claim 1, It is characterized in that The grinding device (30) has a linear guide (32), and the grinding device container (31) is arranged on the linear guide (32) so as to be able to shift along the cutting blades (11).

3. The material shredder (1) according to claim 1 or 2, It is characterized in that The grinding device container (31) has a grinding element support (33), and the grinding element support rotatably holds the grinding elements, so that the grinding elements can rotate around a rotation axis, and the rotation axis is substantially vertically aligned with the rotation axis of the cutting head (10).

4. The material shredder (1) according to any one of the preceding claims, It is characterized in that The grinding device (30) has a grinding element actuator, and the grinding element actuator is designated for selectively adjusting the radial distance between the grinding elements and the cutting head (10).

5. The material shredder (1) according to any one of the preceding claims, It is characterized in that The grinding device (30) has a nozzle unit (35), wherein at least one suction nozzle (35b) is aligned with respect to the cutting circumference for a suction effect and / or an application nozzle (35a) is aligned with respect to the cutting circumference for an application effect.

6. The material shredder (1) according to any one of the preceding claims, It is characterized in that The screen (24) is pivotably held coaxially with the rotational axis of the cutting head (10), and an adjusting device (40) is arranged outside the cutting chamber (3), which acts on the screen (24) such that the radial spacing of the screen (24) from the cutting head (10) and thus the dimensions of the cutting chamber (3) are selectively adjustable.

7. The material grinder (1) according to any one of the preceding claims, characterized in that the screen (24) has a material thickness reducing in cross section at one end side in a peripheral region of the screen (24) called the transition zone, and the stator (20) and the screen (24) are arranged to overlap each other in the transition zone, where the screen (24) is arranged radially inwardly here.

8. The material grinder (1) according to any one of the preceding claims, characterized in that a control unit is provided, which is connected to the grinding device (30) for signal transmission.

9. The material grinder (1) according to any one of the preceding claims, characterized in that a guiding element protruding radially inwards into the cutting chamber (3) is arranged on the stator (20), outside the cutting circumference.

10. The material grinder (1) according to any one of the preceding claims, characterized in that an optical detection of the material to be cut, which is carried out when the material to be cut leaves the cutting chamber (3).

11. The material grinder (1) according to any one of the preceding claims, characterized in that an acoustic sensor is provided, which detects the acoustic oscillations caused when the cutting blade (11) moves past the counter blade (23), wherein the acoustic oscillations are used to determine the wear on the cutting blade (11).

12. The material grinder (1) according to any one of the preceding claims, characterized in that the counter blade (23) is releasably fixed in a blade holder, which is arranged on the stator (20), wherein the blade holder is movable relative to the cutting head (10) such that the counter blade (23) can be moved closer to the cutting circumference in a continuously variable manner.

13. The material grinder (1) according to any one of the preceding claims, characterized in that a blade holder is provided, which is arranged on the stator (20), which has blade seats for a plurality of counter blades (23), and the blade holder is rotatably mountable.

14. The material grinder (1) according to any one of the preceding claims, characterized in that a suction device is provided, which acts on the cutting chamber (3) through the outlet (22) for a suction effect.

15. A comminution device (100), in particular for comminuting recyclable material to be cut The comminution device (100) has a comminution means and a feed device (2) designated for feeding the material to be comminuted to the comminution means. It is characterized in that the comminution means is a material comminutor (1) according to any one of the preceding claims.

16. The comminution device (100) according to claim 15, It is characterized in that a metering device is provided which opens into the feed device (2) and is designated for introducing a metered amount of the material to be comminuted into the cutting chamber (3).

17. The comminution device (100) according to claim 15 or 16, It is characterized in that a conveying device forming a conveying section is provided, wherein the conveying section opens into the feed device (2) and / or the metering device.

18. A maintenance method for a material comminutor (1), the method comprising the following method steps: a) actuating the grinding element radially towards the cutting blade (11), which is arranged on a rotatably mounted rotor of the material comminutor (1) called the cutting head (10), such that the grinding element engages with the cutting edge (12) of the cutting blade (11) for a grinding effect; b) guiding the grinding member to move along the cutting blade (11) for grinding effect, wherein, the cutting head (10) rotates during the process; c) radially actuating a screen (24) arranged at the outlet (22) of the stator (20) such that the radial spacing between the screen (24) and the cutting blade (11) is reduced.

19. The maintenance method according to claim 18, It is characterized in that d) radially actuating an opposing blade (23) arranged on the rotor housing called the stator (20), which rotor housing surrounds the cutting head (10), such that the radial spacing between the cutting blade (11) and the opposing blade (23) is reduced.

20. The maintenance method according to claim 18 or 19, It is characterized in that the method steps are feedback controlled by a control unit.

21. The maintenance method according to any one of claims 18 to 20, It is characterized in that the opposing blade (23) is ground before actuation.

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