Impact crusher

Abstract

The invention relates to an impact crusher with a crushing unit (20) comprising a percussion rotor (30), wherein the percussion rotor (30) carries at least two impact bars (35), wherein the impact bars (35) have a radially outer end (35.1), wherein at least one of the impact bars (41, 42) forms a percussion circle (K) from the radially outer end (35.1), wherein at least one impact arm (41, 42) is associated with the percussion rotor (30), such that in an operating position a crushing gap is formed between the impact circle (K) and a crushing section (41.6) of the impact arm (41), wherein to adjust the crushing gap the crushing section (41.6) The impact rocker (41) is adjusted by means of an adjusting unit (50) in an approach direction by a first adjustment dimension such that it touches a contact point of the impact bar (41), in particular the radially outer end and / or the impact circle, wherein the first adjustment dimension is compared with a first reference value in a measuring device, and wherein the crushing section (41.6) is adjusted by a predetermined gap dimension to create the crushing gap. In order to be able to determine the wear of both the impact bars (35) and the impact rocker (41) in such an impact crusher in a simple manner, it is provided according to the invention that in an additional measuring step the crushing section (41.6) is brought into contact with a reference measuring section (36.1) and a second adjustment dimension is determined and compared with a second reference value.

Description

[0001] The invention relates to a method for determining the wear of an impact rocker of an impact crusher, in particular a rotary impact crusher with a crushing unit having an impact rotor, wherein the impact rotor carries at least two impact bars, wherein the impact bars have a radially outer end, wherein an impact circle is formed by the radially outer end of at least one of the impact bars, wherein at least one impact rocker is assigned to the impact rotor such that, in an operating position, a crushing gap is formed between the impact circle and a crushing section of the impact rocker, wherein, to adjust the crushing gap, the crushing section of the impact rocker is first adjusted by means of an adjusting unit in an infeed direction by a first adjustment dimension such that it touches a contact point of the impact bar, in particular the radially outer end and / or the impact circle,wherein the first setting dimension is compared with a first reference value in a measuring device, and wherein the crushing section is adjusted by a predetermined gap dimension to create the crushing gap.

[0002] EP 0 391 096 B2 discloses a rotary impact crusher comprising a rotor rotatable about an axis within a housing. The rotor carries impact bars which are provided with a free end on the outer circumference of the rotor. These radially outer ends of the impact bar form an impact circle. An impact rocker of a crusher is arranged opposite the rotor. A crushing gap is formed between a crushing section of the impact rocker and the impact circle. The impact rocker can be adjusted by means of an adjusting unit such that the width of the crushing gap can be varied. In order to set a predetermined width of the crushing gap to a predetermined value, the impact rocker is first moved towards the impact circle by means of the adjusting unit while the rotor is running. As soon as the impact rocker contacts the impact circle and thus the outer ends of the impact bar, a mechanical noise is produced. This noise can be recorded with a microphone.In this way, the so-called zero position of the impact rocker is determined. Starting from this zero position, the impact rocker is then retracted using the actuating unit. The travel path is monitored. This allows the desired crushing gap to be set.

[0003] US 10,279,354 B2 discloses a rotary impact crusher with a rotor that again has protruding free ends of impact bars on its outer circumference. This again forms an impact circle. Two impact rockers are assigned to the rotor. Similar to the D1, at least one of the impact rockers in this rotary impact crusher can be adjusted from its basic position to the zero position. The adjustment distance until the zero position is reached can be determined using a displacement sensor. This adjustment distance is compared with a adjustment distance that results when the rotary impact crusher is present with unworn impact bars and unworn impact rocker. In this way, the total wear caused by wear of the impact bars and the impact rocker can be determined.

[0004] Another rotary impact crusher is known from DE 26 55 655 C2. This also describes a measuring device that can determine the total wear of the impact bar and the impact rocker. Rotary impact crushers are also known from, for example, EP 1 287 893 A2 and JP 2002 346410 A.

[0005] The object of the invention is to provide an impact crusher of the type mentioned at the outset in which the wear of both the impact rocker and the impact bar can be determined in a simple manner.

[0006] This task is solved by bringing the crushing section into contact with a reference measuring section in an additional measuring step, thereby determining a second setting dimension and comparing this second setting dimension with a second reference value.

[0007] Similar to the state of the art, the total wear in the system can first be determined by moving the impact rocker from a home position to the zero position. In this zero position, the impact rocker contacts the free end of the impact bar or the impact circle. This can be done while the rotor is running. Contact with the impact bar is detectable by a mechanical noise. This mechanical noise can either be recorded using a signal pickup or it can be recorded acoustically by an operator. The first setting dimension, which occurs when the impact rocker is moved from its predefined home position, can be recorded using a distance sensor and fed into a measuring unit comprising a computing unit. Alternatively, it is also conceivable for this measurement to be carried out while the impact rotor is stationary.In this case, for example, the impact rocker is moved until it comes into contact with the radially outer end of the blow bar. Alternatively, it is also conceivable that in such an operating condition with the impact rotor stationary, the impact rocker with its crushing section is moved against a predetermined contact point on the blow bar. This contact point is preferably arranged at a position on the blow bar that has a comparable level of wear to the radial end of the blow bar. For example, a free surface of the blow bar adjacent to the radial end is a suitable contact point for this. The first setting dimension provides information about the total wear, which results from the addition of the wear on the free end of the blow bar and the crushing section. For this purpose, for example, the previously set width of the crushing gap, which forms the first reference value, can be subtracted from the first setting dimension.The result reflects the total wear.

[0008] After (or before) the first setting dimension has been determined, the second setting dimension can be determined. For this purpose, a relative movement is carried out between the impact rocker and a reference measuring section of the impact rotor from a basic position. This movement is preferably the result of an adjustment of the impact rocker from a basic position towards the impact rotor until the crushing section contacts the reference measuring section of the impact rotor. The reference measuring section is arranged at a point on the impact rotor that is subject to no or only minimal wear. This reference measuring section is preferably arranged in the circumferential area of the impact rotor between two adjacent blow bars. The second setting dimension provides information about the wear of the impact rocker.For example, this second adjustment dimension can be compared in the measuring unit's computing unit with a second reference value, which results when the impact rocker is adjusted from its home position in a non-worn state toward the reference measuring section. The wear of the impact rocker is determined by calculating the difference, in which the second reference value is subtracted from the second adjustment dimension. The wear of the impact bar can then be determined in the computing unit by calculating the difference between the total wear and the wear of the impact rocker.

[0009] In this way, the wear of the impact bar(s) and the wear of the impact arm can be measured separately and easily. In particular, this does not require the use of complex optical systems or the need for an operator to enter the crushing chamber with measuring equipment.

[0010] According to a preferred embodiment of the invention, the reference measuring section can be formed on the impact rotor. This results in a simple design. In particular, the reference measuring section can be arranged on the impact rotor such that it is positioned within the range of motion defined by the pivot bearing of the impact rocker.

[0011] In particular, it can be provided that the impact rotor is rotated into a position in which the reference measuring section is opposite the crushing section of the impact rocker, that the rotational movement of the impact rotor is then stopped or slowed down, and that the crushing section is subsequently moved until it rests against the reference measuring section. The crushing section is preferably adjusted by pivoting the entire impact rocker about its pivot bearing. It can preferably be provided that the adjusting movement of the impact rocker is effected by an adjusting unit which is used to support the impact rocker with the crushing gap adjusted, and wherein this adjusting unit serves to adjust the width of the crushing gap.

[0012] An inventive design of an impact crusher can be such that a sensor, in particular a force gauge, is used to determine the contact of the crushing section with the reference measuring section, and that a switching unit stops the actuating movement of the crushing section toward the reference measuring section or the actuating movement of the reference measuring section toward the crushing section when the sensor emits a contact signal. In this case, it can be provided that the sensor is integrated into the actuating unit, which is used to support the impact rocker when the crushing gap is adjusted. For example, the sensor can have a strain gauge, or the sensor can detect when the actuating unit no longer performs any movement due to the contact between the crushing section and the reference measuring section. For example, the sensor can then be designed as a displacement sensor.

[0013] According to the invention, it can be provided that in the contact position in which the breaking section contacts the reference measuring section, the travel path as a second setting dimension of the impact rocker or of a part of the impact rocker is determined directly or indirectly by means of the measuring device, in particular the deflection of the impact rocker, and is compared with the second reference value. In this procedure, the position of the impact rocker is evaluated when contact is made with the reference measuring section. For example, the angular position of the impact rocker can be evaluated, which results from a rotation of the impact rocker about its pivot bearing. This angular deflection can be compared with a second reference value, which results from the rotation of an impact rocker in a non-worn state.

[0014] Alternatively, it is also conceivable for the impact rocker to be moved from a predetermined reference position until the crushing section is in contact with the reference measuring section. The extent of the adjustment is determined as a second value directly or indirectly using the measuring device and compared with the second reference value. In this procedure, the resulting travel path of the impact rocker is evaluated. The reference positions of the impact rocker can be formed from any predetermined and previously defined position of the impact rocker.

[0015] One conceivable variant of the invention is such that an adjusting device is provided with which the impact rotor is rotated into a predetermined angular position and stopped there, with the crushing section facing the reference measuring section. The adjusting device can be formed by the main drive of the impact crusher, which drives the impact rotor. Furthermore, it is conceivable for the impact rotor to be driven by an auxiliary drive in order to move it into the desired position. The auxiliary drive can in particular be formed by a separate motor unit that acts on the impact rotor in addition to the main drive. More preferably, it can alternatively also be provided that the auxiliary drive is formed by a manually operable adjusting device. For example, with such an adjusting device, the impact rotor can be manually rotated by the operator into the desired position.

[0016] A significantly simplified measurement acquisition results if one or more surface areas of the impact rotor are designed to be used as a reference measuring section and the impact rotor is adjusted so that one of the reference measuring sections is opposite the crushing section. The crushing section of the impact rocker can then be quickly assigned to the nearest reference measuring section in order to record the second control value. Measurement acquisition can be carried out particularly easily if one or more of the reference measuring sections, in a side view perpendicular to the axis of rotation of the impact rotor, have the shape of a circular segment orbiting around the axis of rotation of the impact rotor. The reference measuring sections are then all at the same distance from the axis of rotation of the impact rotor.It is therefore not absolutely necessary to take the angular position of the impact rotor into account if the crushing section is adjacent to the desired reference measuring section.

[0017] It can also be provided that the position of the impact rotor, in particular the angular position of the impact rotor, is recorded and transmitted to the measuring device. In this case, it can be provided in particular that several reference measuring sections merge into one another, preferably merge into one another continuously. The individual reference measuring sections can be stored in the measuring device in correlation with the position, in particular the angular position of the impact rotor. The crushing section of the impact rocker then only needs to be placed against one, preferably the nearest, reference measuring section. The measuring device then detects the orientation, in particular the angular position of the impact rotor, and this detected orientation is then assigned to the position of the reference measuring section via the measuring device. This position of the reference measuring section can then be included in the determination of the second setting dimension.

[0018] According to a conceivable variant of the invention, it can be provided that one or more of the reference measuring sections, in a side view perpendicular to the axis of rotation of the impact rotor, form a cross-sectional shape that changes in the circumferential direction of the impact rotor, in particular the shape of a spiral arc segment circulating around the axis of rotation of the impact rotor, and that the radial distance of at least some of the surface areas of the reference measuring sections from the axis of rotation of the impact rotor is stored in a memory unit of the measuring device.

[0019] If several measurements are planned, preferably at consistent intervals, to determine the first and second adjustment dimensions, and if the measuring device in a computing unit calculates the expected remaining service life of the impact bar and / or the impact rocker from the determined adjustment values, a wear forecast can be easily performed. In particular, it can then be determined whether the impact rocker and / or the impact bar has sufficient remaining service life for an upcoming machining task.

[0020] The wear prediction can be further refined if a material characteristic of the material to be shredded is fed to the computing unit, and the computing unit determines the remaining service life of the blow bar and / or the impact rocker based on the material characteristic. The material characteristic can be determined, for example, by taking samples and evaluating them, for example, by determining the hardness or abrasiveness of the material to be shredded. Similarly, a material characteristic, such as hardness or abrasiveness, can be determined from the measured wear.

[0021] The invention is explained in more detail below with reference to an embodiment illustrated in the drawings. They show: Figure 1 a schematic representation of an impact crusher in side view and partly in section, Figure 2in side view a detailed representation of a crushing unit of the impact crusher according to Figure 1 and Figure 3 the representation according to Figure 2 in a changed operating position.

[0022] Figure 1 shows a side view, partially in section, of an impact crusher designed as a rotary impact crusher. The impact crusher can be designed as a mobile system with a chassis 13 and a chain drive 15. It has a feed unit 10, a pre-screening unit if required, a crushing unit 20, and at least one crusher discharge belt 24.

[0023] A hopper 11 can be arranged in the area of the feed unit 10. The hopper 11 has hopper walls. It directs the supplied feed material to a conveyor unit 12, which can preferably be designed as a vibrating feed chute.

[0024] The conveyor unit 12 conveys the feed material to a screening unit 14, which can be formed, for example, by a double-deck pre-screen. In the present exemplary embodiment, the screening unit 14 has an upper double-deck heavy-piece screen 14.1, which is designed as a comparatively coarse screen and forms an upper deck. Below this, a comparatively finer screen is arranged, which forms a lower deck 14.2. It is set into circular oscillation by a drive. The upper deck separates a fine fraction and a medium grain from the material to be crushed. The lower deck separates the fine fraction from the medium grain. The fine fraction can either be guided out of the material comminution system by means of a side discharge belt 14.3 or fed back to the medium grain by appropriately positioning a bypass flap. The medium grain is guided via a bypass 23 past the crushing unit 20 to the crusher discharge belt 24.At the end of the pre-screening, the material to be crushed is fed to the crushing unit 20 via a crusher inlet 22.

[0025] The crushing unit 20 has a crusher housing 21 in which a percussion rotor 30 is rotatably mounted. The percussion rotor 30 can be driven by a main drive 16 of the impact crusher. The percussion rotor 30 rotates about a rotational axis 32.

[0026] From the Figure 2 and 3 The structure of the crushing unit 20 becomes clearer. As these drawings illustrate, the impact rotor 30 has a carrier 31 that has a plurality of receptacles 33 on its outer circumference. In the present embodiment, three receptacles 33 are provided. However, it is also conceivable that only two or more than three receptacles 33 are used.

[0027] Impact bars 35 can be inserted into the receptacles 33 in an interchangeable manner and can be fastened in the receptacles 33 by means of a fastening section 35.4.

[0028] For example, it is conceivable that a preferably replaceable bearing piece 34.1 is inserted at the rear of the impact bars 35 in the receptacle 33 in the direction of rotation V to fasten the impact bars 35. The rear of the impact bar 35 can be supported against this bearing piece 34.1. Preferably, at least one clamping wedge 34.2, 34.3 is installed in front of the impact bar 35 in the direction of rotation V of the impact rotor 30. In the present embodiment, two clamping wedges 34.2, 34.3 are provided for a stable fastening of the impact bar 35. The clamping wedges 34.2, 34.3 can be adjusted using clamping devices to press the impact bar 35 against the rear bearing piece 34.1.

[0029] The impact bars 35 each have a radial end 35.1. In the present embodiment, the radially outer ends 35.1 of the impact bars 35 lie on a common impact circle K.

[0030] The radial ends 35.1 of the impact bars 35 are adjoined by flanks 35. The flanks 35.2 extend at a distance from the impact circle K.

[0031] Adjacent to the radial ends 35.1, the impact bars 35 have front surfaces 35.3. These front surfaces 35.3 protrude beyond a rotor circumferential surface 36.

[0032] Between the receptacles 33 and thus between the impact bars 35, the rotor circumferential surface 36 forms reference measuring sections 36.1. Figure 2As can be seen, the reference measuring sections 36.1 are formed by arc segments that extend spirally around the rotational axis 32 of the impact rotor 30. Accordingly, the distance between the rotor circumferential surface 36 and the rotational axis 32 increases continuously, at least in some sections. In the present exemplary embodiment, this distance increases continuously in the circumferential direction. However, it is also conceivable for the distance to increase counter to the circumferential direction.

[0033] Preferably, a reference measuring section 36.1 is arranged in each intermediate region between the impact bars 35. However, it is also conceivable that only one reference measuring section 36.1 is provided on the rotor circumferential surface 36.

[0034] The crushing unit 20 has two impact rockers 41, 42. These impact rockers 41, 42 are assigned to the impact rotor 30.

[0035] The impact rocker 42 has a rocker body 42.1, which is pivotally connected to the chassis 13 via a pivot bearing 42.2. The rocker body 42.1 has an impact surface 42.3 at the front, which is associated with the impact rotor 30. At its end facing away from the pivot bearing 42.2, the impact surface 42.3 terminates in a crushing section 42.6.

[0036] To pivot the impact rocker 42 around the pivot bearing 42.2, an actuating unit is used, which is Figure 2 is not shown.

[0037] The impact rocker 41 has a rocker body 41.1, which is pivotally connected to the chassis 13 via a pivot bearing 41.2. The rocker body 41.1 has an impact surface 41.3 at the front, which is assigned to the impact rotor 30. At its end facing away from the pivot bearing 41.2, the impact surface 41.3 has a receptacle 41.4. A wear insert 41.5 is preferably replaceably fastened in this receptacle 41.4. The wear insert 41.5 is made of a material that is harder than the impact surface 41.3. The wear insert 41.5 is preferably made of a hard material. The wear insert 41.5 has a breaking section 41.6 at its end facing away from the pivot bearing 41.2.

[0038] An actuating unit 50 is used to pivot the impact rocker 41 around the pivot bearing 41.2. The actuating unit 50 can be formed by a hydraulic cylinder. The hydraulic cylinder has a cylinder 51 in which a piston is adjustably guided. A piston rod 52 is coupled to the cylinder 51. The end of the piston rod 52 carries a coupling piece 53. The coupling piece 53 is pivotally coupled to the rocker body 41.1.

[0039] By means of the adjusting unit 50, a resistance is formed against which the impact rocker 41 is arranged in the crushing chamber so that it can swing freely to a limited extent.

[0040] The adjusting unit 50 also serves to adjust the distance of the crushing section 41.6 from the impact circle K. For this purpose, the piston is moved in the hydraulic cylinder, whereby, depending on the direction of movement of the piston, the piston rod 52 moves increasingly into or out of the cylinder 51.

[0041] As mentioned above, during operation, the material to be crushed is fed to the impact rotor 30. The impact rotor 30 rotates at high speed around the rotational axis 32. The impact bars 35 engage with the material to be crushed with their front surfaces 35.3, accelerating it. The material to be crushed is thrown against the impact surfaces 42.3 and 41.3 of the impact rockers 42 and 41. This crushes the material to be crushed. If the material has a grain size that allows it to pass between the crushing section 42.6 and the impact circle K, the crushed material is further crushed by the impact rocker 41. When a grain size is reached that allows the crushed material to fall through the crushing gap formed between the crushing section 41.6 and the impact circle K, the crushed material is conveyed to the crusher discharge belt 24.

[0042] During operation, both the impact rocker 41 and the impact bars 35 are subject to significant wear. This causes the crushing gap to increase. If the crushing gap is too wide, it must be readjusted. Adjustment unit 50 is used for this purpose.

[0043] According to the invention, the wear of the impact bars 35 and, separately, the wear of the impact rocker 41 can be determined. To determine wear and perform a measurement process, the material feed is stopped. The impact rotor 30 continues to operate until there is no more crushed material in the crushing unit 20. The impact rotor 30 now runs freely without being influenced by the crushed material. The impact rotor 30 is then stopped. The impact rotor 30 is then rotated until the crushing section 41.6 of the impact rocker 41 is opposite a reference measuring section 36.1 of the impact rotor 30.

[0044] The rotation of the impact rotor 30 can be carried out, for example, with a manually driven auxiliary drive or an electric motor driven auxiliary drive.

[0045] If one of the reference measuring sections 36.1 is opposite the crushing section 41.6, the impact rocker 41 is moved by means of the actuating unit 50, starting from a defined basic position, in the direction of the reference measuring section 36.1, until the crushing section 41.6 rests against the reference measuring section 36.1 (see Figure 2). Contact with the reference measuring section 36.1 can be determined by means of a force measuring system, for example in the hydraulic cylinder or with another suitable sensor. The deflection of the impact rocker 41 from the home position is measured as the second setting dimension. For example, this can be determined by an angle measurement on the pivot bearing 41.2 of the impact rocker 41 or based on the travel movement of the hydraulic cylinder (for example, the piston rod 52 or the piston). The reference measuring sections 36.1 are arranged between the impact bars 35 in an area that is subject to no or at most only minimal wear.

[0046] In a memory unit of the impact crusher's measuring device, the distance of the rotor's peripheral surface 36 from the rotational axis 32 in the area of the reference measuring sections 36.1 can be stored as a functional relationship depending on the angular position of the impact rotor 30. It is also conceivable that pairs of values are stored in the memory unit of the measuring device, with certain angular positions of the impact rotor 30 being assigned to distances of the rotor's peripheral surface 36 from the rotational axis 32.

[0047] The second setting dimension is compared with a second reference value in a computing unit of the measuring device. The second reference value is the corresponding deflection of a non-worn impact rocker 41 upon contact with the same area of the reference measuring section 36.1 as the crushing section 41.6. Here, too, a functional relationship or value pairs for the second reference value can be stored in the memory unit of the measuring device.

[0048] By forming the difference, whereby the second reference value is subtracted from the second setting dimension, the wear of the impact rocker 41 in the area of the crushing section 41.6 can be determined.

[0049] It is also conceivable that only an average value of the distance of the rotor circumferential surface 36 in the area of the reference measuring section 36.1 is stored in the memory unit of the measuring device as a second reference value. Furthermore, it is conceivable that the rotor circumferential surface 36, as the reference measuring section 36.1, forms a circular arc or approximately a circular arc that revolves with a radius around the rotational axis 32. In this case, for example, the radius of the circular arc can be used as the second reference value.

[0050] The impact rocker 41 is then returned to a home position by the actuating unit 50. The impact rotor 30 can then be rotated, for example, by means of the main drive 16 or by means of an auxiliary drive.

[0051] When the impact rotor 30 rotates, the impact rocker 41 is adjusted from a predefined basic position by means of the adjusting unit 50 until the crushing section 41.6 touches the impact circle K. When the impact rotor 30 rotates, contact is then created between the impact rocker 41 and the radial end 35.1 of the impact bar 35, which contact can be detected acoustically, for example with a microphone or by an operator.

[0052] Within the scope of the invention, the contact of the impact rocker 41 with the radial end 35.1 of the impact bar 35 can be acoustically detected using a microphone, as mentioned above. Additionally or alternatively, this contact can also be detected using a suitable signal sensor, for example, a contact sensor, in particular an acceleration sensor.

[0053] The deflection of the impact rocker 41 from its home position until it contacts the impact circle K is determined as the first setting dimension. This first setting dimension can be determined, for example, by measuring the angle at the pivot bearing 41.2 of the impact rocker 41 or by the deflection of the hydraulic cylinder (e.g., the travel of the piston rod 52 or the piston of the hydraulic cylinder). In other words, the "zero position" of the impact rocker 41 is set and determined.

[0054] The first setting dimension can also be determined with the impact rotor 30 stationary. In this case, the crushing section 41.6 is moved against the radial end 35.1 of the impact bar 35, as Figure 3 The measured deflection from the predefined home position of the impact rocker 41 is then used as the first setting dimension. The assignment of the impact rotor 30 to the crushing section 41.6 can again be achieved by a manual or motorized auxiliary drive.

[0055] The first adjustment dimension is compared with a first reference value. The first reference value is the corresponding deflection of a non-worn impact rocker 41 and a non-worn blow bar 35 upon contact of the crushing section 41.6 with the impact circle K or a contact point of the blow bar 35.

[0056] By forming the difference, whereby the first reference value is subtracted from the first setting dimension, the total wear can be determined, which results from the wear of the crushing section 41.6 and the wear of the blow bar 35.

[0057] If the total wear and the wear of the impact rocker 41 are known, the wear of the impact bar 35 can be determined by taking the difference.

[0058] In this way, the wear of the impact bar 35 and the wear of the impact rocker 41 can be easily determined in isolation, without the operator having to enter the crushing chamber with measuring equipment and / or without the need to use complex optical measuring devices.

[0059] In the example described above, the second dimension was determined first, followed by the first dimension. Of course, the procedure can also be reversed: first, the first dimension, followed by the second dimension.

[0060] After the measuring process is complete, the impact rocker 41 can be pivoted again using the adjusting unit 50 until the desired width of the crushing gap is set. For example, from the crushing gap position "zero," the impact rocker 41 can be moved back to the desired distance in the crushing gap, as is common in the state of the art.

[0061] With knowledge of the wear on the impact rocker 41 and the impact bars 35, a wear forecast can be made. For example, it can be determined whether the condition of the impact rocker 41 and / or the impact bars 35 is sufficient for planned material processing.

[0062] For continuous wear prediction, the invention may provide for the above-described process for determining wear on the impact rocker 41 and the impact bars 35 to be performed each time the crushing gap is adjusted or at regular intervals (e.g., once per shift, always at the beginning or end of work, etc.). In this way, wear can be observed, and a prediction can be made to determine when the impact bars 35 or the wear inserts 41.5 need to be replaced.

[0063] How Figure 1As further shown, the crushed material coming from the impact rotor 30, together with the material guided in the bypass 23, reaches the crusher discharge belt 24. A magnetic separator 17 can be arranged above the crusher discharge belt 24. This magnetic separator 24 separates any iron particles present in the crushed material. Accordingly, it attracts these iron particles and conveys them laterally out of the transport area of the crusher discharge belt 24.

[0064] At the end of the crusher discharge belt 24, for example, an additional screening unit 24.1 with a screening deck can be provided. The screening deck 24.1 screens out a fine material fraction 24.2. This falls onto another conveyor belt 25. The additional conveyor belt 25 conveys the fine material fraction 24.2 onto a crushed material pile 14.4.

[0065] The material not screened by the screening unit 24.1 is conveyed to a return belt 26. By means of the return belt 26, this rock fraction is returned and passed through the crushing unit 20 again.

Claims

1. A method to determine the wear of an impact rocker (41) of an impact crusher, in particular of a rotary impact crusher, the impact crusher having a crusher unit (20), which has an impact rotor (30), wherein the impact rotor (30) bears at least two impact bars (35), wherein the impact bars (35) having a radially outer end (35.1), wherein the radially outer end (35.1) of at least one of the impact bars (35) forms an impact circle (K), wherein at least one impact rocker (41, 42) is assigned to the impact rotor (30) such that, in an operating position, a crushing gap is formed between the impact circle (K) and a crushing section (41.6) of the impact rocker (41), wherein for setting the crushing gap, first the crushing section (41.6) of the impact rocker (41) is adjusted by means of an actuating unit (50) in a feed direction by a first adjustment value such that it contacts a contact point of the impact bar (35), in particular the radially outer end and / or the impact circle, wherein the first adjustment value is compared to a first reference value in a measurement device, and wherein the crushing section (41.6) is adjusted by a predetermined gap dimension to create the crushing gap, is characterized in that, in an additional measurement step, the crushing section (41.6) is brought into contact with a reference measurement section (36.1) and in doing so, a second adjustment value is determined and compared to a second reference value.

2. The method according to claim 1, characterized in that the reference measurement section (36.1) is formed at the impact rotor (30).

3. The method according to claim 2, characterized in that the impact rotor (30) is rotated to a position in which the reference measurement section (36.1) faces the crushing section (41.6), in that the rotational motion of the impact rotor (30) is then stopped or slowed down, and in that subsequently the crushing section (41.6) is moved until it rests against the reference measurement section (36.1).

4. The method according to one of claims 1 or 2, characterized in that a sensor, in particular a force gauge, is used, which determines the contact of the crushing section (41.6) with the reference measurement section (36.1), and in that a switching unit is used to stop the actuating motion of the crushing section (41.6) in the direction of the reference measurement section (36.1) or the actuating motion of the reference measurement section (36.1) in the direction of the crushing section (41.6) when the sensor emits a contact signal.

5. The method according to any one of claims 1 to 4, characterized in that, in the contact position, in which the crushing section (41.6) contacts the reference measurement section (36.1), the travel of the impact rocker (41) or of a part of the impact rocker (41) is determined directly or indirectly by means of the measurement device, in particular the deflection of the impact rocker (41), and is compared to the second reference value, or in that the impact rocker (41) is moved from a predetermined reference position until the crushing section (41.6) is in contact with the reference measurement section (36.1), and in that the degree of displacement is directly or indirectly determined by the measurement device and compared to the second reference value.

6. The method according to any one of claims 1 to 5, characterized in that an actuator is provided, which is used to rotate the impact rotor (30) to a predetermined angular position and stopped there, wherein the crushing section (41.6) faces the reference measurement section (36.1).

7. The method according to claim 6, characterized in that the actuator has an auxiliary drive, which is provided in addition to the main drive (16) driving the impact rotor (30) and by means of which auxiliary drive the impact rotor (30) is rotated manually or in a motorized manner.

8. The method according to any one of claims 1 to 7, characterized in that one or more surface areas of the impact rotor (30) are adapted to be used as a reference measurement section (36.1).

9. The method according to claim 8, characterized in that the impact rotor (30) is adjusted such that one of the reference measurement sections (36.1) faces the crushing section (41.6), and that the position of the impact rotor (30), in particular the angular position of the impact rotor (30), is detected and transmitted to the measurement device.

10. The method according to claim 8 or 9, characterized in that one or more of the reference measurement sections (36.1) have the shape of a circular segment rotating about the axis of rotation (32) of the impact rotor (30) in side view perpendicular to the axis of rotation (32) of the impact rotor (30) or in that one or more of the reference measurement sections (36.1), in side view perpendicular to the axis of rotation (32) of the impact rotor (30), form a cross-sectional shape that changes in the circumferential direction of the impact rotor (30), in particular the shape of a spiral arc segment rotating about the axis of rotation (32) of the impact rotor (30), and in that the radial distance of at least some of the surface areas of the reference measurement section (36.1) from the axis of rotation (32) of the impact rotor (30) are stored in a memory unit of the measurement device.

11. The method according to any one of the claims 1 to 10, characterized in that several measurements are performed, preferably at constant time intervals, in which the first and the second adjustment values are determined, and in that the measurement device in a computing unit determines the expected remaining service life of the impact bar (35) and / or of the impact rocker (41) from the actuating values determined.

12. The method according to claim 11, characterized in that a material property of the material to be crushed is fed to the computing unit, and in that the computing unit determines the remaining service life of the impact bar (35) and / or the impact rocker (41) taking into account the material property.

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