AU2022329501A1 - Controller of crushing system, crushing system, and method of controlling the same - Google Patents

Abstract

In the present invention, a controller for a crushing system comprises a gyratory crushing machine and a feeding machine. The controller is provided with a processing circuit, wherein the processing circuit does the following: acquires a load index directly or indirectly representing a crushing load on the gyratory crushing machine; calculates a particle size ratio in which a production volume of a product that is within a prescribed particle size range as obtained from a crushed product which has been crushed by the gyratory crushing machine is represented as a ratio relative to a prescribed reference production volume; generates a load index target value on the basis of the acquired load index and a correlation between the load index and the particle size ratio; and generates a control command value from the load index and the load index target value.

Description

DESCRIPTION Title of Invention: CONTROLLER OF CRUSHING SYSTEM, CRUSHING SYSTEM, AND METHOD OF CONTROLLING THE SAME Technical Field

[0001] The present disclosure relates to a controller of a crushing system that includes a gyratory crusher, and also relates to the crushing system and a method of controlling the same.

Background Art

[0002] Conventionally, there has been a known gyratory crusher in which a truncated conical mantle located inside a conical-cylindrical concave is caused to turn eccentrically, and thereby objects to be crushed (hereinafter, referred to as "to-be-crushed objects"), such as rude ore, are caught and crushed between the concave and the mantle. When the to-be-crushed objects are fed from above the gyratory crusher, the to-be-crushed objects are captured and crushed into a predetermined grain size in a crushing chamber between the turning mantle and the concave, and then discharged. At the time, by changing the feeding amount of the to-be crushed objects fed to the gyratory crusher or by changing the size of the discharge opening of the crushing chamber, which is called "the set", the production amount and grain size of a product discharged from the gyratory crusher can be adjusted.

[0003] In the gyratory crusher, the discharged product is classified into predetermined grain size ranges, so that multiple products corresponding to the respective grain size ranges are sorted out. For each sorted-out product, it is required that the proportion, i.e., the ratio, of the product to the feeding amount of the to-be-crushed objects should be adjusted in accordance with the demand for the product. In the case of conventional gyratory crushers, for each grain size range, the ratio of the sorted-out product is visually checked, and based on that assessment, an operator changes the feeding amount of the to-be-crushed objects, or adjusts the set.

Citation List Patent Literature

[0004] PTL 1: Japanese Laid-Open Patent Application Publication No. 2003-200079 PTL 2: Japanese Laid-Open Patent Application Publication No. 2019-202245

Summary of Invention Technical Problem

[0005] In relation to the above, Patent Literature 1 discloses a crushing system that performs crushing in a staged manner by using multiple crushers. In the crushing system, based on the actual values of production amounts or production proportions of products in their respective grain size ranges, and a rude ore feeding amount and setting values of the respective crushers at the time, the relationship between them is estimated. By using the estimated relationship, the setting values of the respective crushers are determined so as to achieve a desired production amount or desired production proportion for each product. However, even in a case where the setting values of the respective crushers are determined so as to achieve a desired production amount or desired production proportion for each product, a result of the crushing may vary depending on the properties of the rude ore fed into the crushers, such as the size of the rude ore, the amount of water adhered thereto, etc. For these reasons, even in the case of the above described configuration, there is room for improvements to ensure stable control of the crushers, thereby achieving the desired production amount of a product in a predetermined grain size range.

[0006] Patent Literature 2 discloses: measuring a load index that indicates a crushing load on a gyratory crusher; and in a case where a measurement value of the load index falls out of a predetermined regular range, determining a new operating amount based on a deviation of the measurement value of the load index from a target value of the load index. According to this configuration, by setting an operating amount that allows the load to converge to the target value, stable production is achieved. However, in the case of this configuration, an operator needs to set the target value of the load. The operator needs to estimate, from their intuition or experience, the target value of the load to achieve a desired production amount of a product in a predetermined grain size range. Thus, even in the case of the above-described configuration, there is room for improvements to make it possible to intuitively set the target value so as to achieve a desired production amount of a product in a predetermined grain size range.

[0007] The present disclosure has been made to solve the above-described problems. An object of the present disclosure it to provide a controller of a crushing system, the crushing system, and a method of controlling the same, which make it possible to intuitively set a target value for achieving a desired production amount of a product in a predetermined grain size range and to stably control a gyratory crusher to achieve the desired production amount.

Solution to Problem

[0008] A controller of a crushing system according to one aspect of the present disclosure is a controller of a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the controller including processing circuitry. The processing circuitry: obtains a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculates a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generates the load index target value based on the obtained load index and a correlation between the load index and the grain size ratio; and generates a control command value from the load index and the load index target value. The controller controls at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.

[0009] A crushing system according to another aspect of the present disclosure includes: a gyratory crusher; a feeder that feeds objects to be crushed to the gyratory crusher; and the controller configured as described above.

[0010] A control method according to yet another aspect of the present disclosure is a method of controlling a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the method including: detecting a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculating a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generating the load index target value based on the detected load index and a correlation between the load index and the grain size ratio; and generating, from the load index and the load index target value, a control command value to control at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.

Advantageous Effects of Invention

[0011] The present disclosure makes it possible to intuitively set a target value for achieving a desired production amount of a product in a predetermined grain size range and to stably control a gyratory crusher to achieve the desired production amount.

Brief Description of Drawings

[0012] FIG. 1 shows a schematic configuration of a crushing system according to one embodiment of the present disclosure. FIG. 2 shows a schematic configuration of one example of a gyratory crusher applied to the crushing system of FIG. 1. FIG. 3 is a block diagram showing a schematic configuration of a control system of the crushing system of FIG. 1. FIG. 4 is a block diagram showing a control block configuration of a controller in the present embodiment. FIG. 5 is a block diagram showing a configuration example of a target value generator of FIG. 4. FIG. 6 is a graph showing a correlation between a load index and a grain size ratio in the present embodiment. FIG. 7 is a block diagram showing a configuration example of a control command generator of FIG. 4. FIG. 8 is a graph showing a relationship between electric power supplied to an electric motor of a transport conveyor and a transportation amount per unit time of a product transported by the transport conveyor. FIG. 9 is a block diagram showing a configuration example of a grain size ratio calculator of FIG. 5. FIG. 10 illustrates graphs showing results of simulation of a control mode based on the present embodiment. FIG. 11 shows a schematic configuration of another example of a gyratory crusher applied to the crushing system of FIG. 1.

Description of Embodiments

[0013] Hereinafter, one embodiment of the present disclosure is described with reference to the drawings.

[0014] [Overview of crushing system] FIG. 1 shows a schematic configuration of a crushing system according to one embodiment of the present disclosure. A crushing system 100 according to the present embodiment includes a gyratory crusher 1, a feeder 4, a load index detector 140, and a controller 9. The feeder 4 feeds objects to be crushed (hereinafter, referred to as "to-be-crushed objects") to the gyratory crusher 1. The load index detector 140 detects a load index that directly or indirectly indicates a crushing load on the gyratory crusher 1. The controller 9 controls at least one of the gyratory crusher 1 or the feeder 4, such that the load index is within a reference range that is based on a load index target value.

[0015] The feeder 4 includes, for example, a conveyor 40, and the feeding amount of the to- be-crushed objects fed by the feeder 4 to the gyratory crusher 1 is adjustable. The conveyor 40 is driven by an electric motor 41, which is a variable speed motor. AsshowninFIG.2 described below, the electric motor 41 is driven by a motor driver 43.

[0016] The crushing system 100 includes: a classifier 110, which performs, after the to-be crushed objects are crushed by the gyratory crusher 1, classification to classify the crushed objects in terms of grain size; and a middle conveyor 113, which transports the crushed objects from a crushed object outlet of the gyratory crusher 1 to the classifier 110. The middle conveyor 113 is driven by an electric motor 114.

[0017] In the present embodiment, the classifier 110 performs two-stage classification including the use of a coarse first sieve 111 and a fine second sieve 112. As a result, the objects that have been crushed by the gyratory crusher 1 are classified into: a first product GI, which has passed through both the first sieve 111 and the second sieve 112 and which is within a first grain size range; a second product G2, which has passed through the first sieve 111 but is not able to pass through the second sieve 112 and which is within a second grain size range; and a third product G3, which is not able to pass through the first sieve 111 and which is within a third grain size range. That is, when these products GI, G2, and G3 are arranged in descending order of average grain size, the orderis G3 > G2 > G1. Alternatively, the classifier 110 may perform one-stage classification, or may perform the classification in three or more stages.

[0018] Further, the crushing system 100 includes the following conveyors located downstream of the classifier 110: a first transport conveyor 115, which transports the first product G1, which is sorted out by the classification by the classifier 110; a second transport conveyor 116, which transports the second product G2, which is sorted out by the classification by the classifier 110; and a third transport conveyor 117, which transports the third product G3, which is sorted out by the classification by the classifier 110. In the present embodiment, the third product G3 having the greatest average grain size is, after being transported by the third transport conveyor 117, fed into the gyratory crusher 1 again. The first product G Iand the second product G2 are final products produced in the crushing system 100. Thatis,the crushing system 100 is a production apparatus to produce the first product G Iand the second product G2.

[0019] In this manner, the classifier 110 classifies the product produced by the gyratory crusher 1 into two or more types of products with reference to their grain size. Further, the transport conveyors include two or more transport conveyors 115, 116, and 117, which transport the two or more types of products, respectively.

[0020] The first transport conveyor 115 is driven by an electric motor 118. Thesecond transport conveyor 116 is driven by an electric motor 119. The third transport conveyor 117 is driven by an electric motor 120.

[0021] The crushing system 100 includes a grain size index detector 130, which detects a grain size index Pact. The grain size index Pact directly or indirectly indicates a production amount of a product Gj ( = 1, 2, 3) in a predetermined grain size range, the product Gj being sorted out by the classification by the classifier 110. In the present embodiment, the grain size index detector 130 detects, as the grain size index Pact, a value that indicates a production amount per unit time of the product Gj on each of the transport conveyors 115, 116, and 117.

[0022] More specifically, the grain size index detector 130 includes: a first electric power measurer 131, which measures first electric power P1 supplied to the electric motor 118, which drives the first transport conveyor 115; a second electric power measurer 132, which measures second electric power P2 supplied to the electric motor 119, which drives the second transport conveyor 116; and a third electric power measurer 133, which measures third electric power P3 supplied to the electric motor 120, which drives the third transport conveyor 117. Each of the electric power measurers 131, 132, and 133 may be an electric power meter that directly measures electric power. Alternatively, each of the electric power measurers 131, 132, and 133 may include an ammeter and voltmeter, and may calculate electric power from a current and voltage measured by the ammeter and voltmeter.

[0023] In the present embodiment, as described below, the first electric power P1 measured by the first electric power measurer 131 may be used as a grain size index of thefirst product GI. The second electric power P2 measured by the second electric power measurer 132 may be used as a grain size index of the second product G2. The third electric power P3 measured by the third electric power measurer 133 may be used as a grain size index of the third product G3.

[0024] The crushing system 100 further includes a feeding amount detector 150, which detects a value Pall that indicates a feeding amount per unit time of the to-be-crushed objects fed to the gyratory crusher 1. In the present embodiment, the feeding amount detector 150 detects a value that indicates a feeding amount per unit time of the to-be-crushed objects at the conveyor of the feeder 4. More specifically, the feeding amount detector 150 includes a fourth electric power measurer 134, which measures fourth electric power P4 supplied to the electric motor 41, which drives the conveyor 40. Alternatively, the feeding amount detector 150 may include a fifth electric power measurer 135, which measures fifth electric power supplied to the electric motor 114, which drives the middle conveyor 113. Further alternatively, as described below, in the case of calculating the feeding amount by using the grain size index of the first product G1, the grain size index of the second product G2, and the grain size index of the third product G3, the feeding amount detector 150 is unnecessary.

[0025] [Overview of the gyratory crusher] FIG. 2 shows a schematic configuration of one example of a gyratory crusher applied to the crushing system of FIG. 1. The gyratory crusher 1 illustratively shown in FIG. 2 is a hydraulic gyratory crusher in which the operation of a hydraulic cylinder 6 is controllable via a hydraulic circuit 7, which will be described below. The gyratory crusher 1 according to the present embodiment includes a hopper 2, a mantle 13, and a concave 14. The mantle 13 is fixed to a main shaft 5, which turns eccentrically. The concave 14 includes a crushing chamber 16 therein. The hopper 2 stores the to-be-crushed objects fed from the feeder 4. The to-be crushed objects that are dropped from the hopper 2 are fed into the crushing chamber 16. In the crushing chamber 16, the to-be-crushed objects are caught and crushed between the concave 14 and the mantle 13.

[0026] The gyratory crusher 1 further includes a frame 3, which includes a top frame 31 and a bottom frame 32. The hopper 2 is located over the top frame 31. The conical-cylindrical concave 14 is held on the inner periphery of the top frame 31. The truncated conical mantle 13 is located inside the concave 14. The concave 14 and the mantle 13 include their respective crushing surfaces that face each other with a gap therebetween, and the crushing chamber 16 is defined as a space between the crushing surface of the concave 14 and the crushing surface of the mantle 13, the space having a wedge-shaped vertical cross section.

[0027] The mantle 13 is mounted via a mantle core 12 fixed to the upper part of the main shaft 5. The main shaft 5 is located inside the frame 3 in a state where the center axis of the main shaft 5 is inclined relative to the vertical direction. The upper end of the main shaft 5 is rotatably supported by an upper bearing 34, which is located on the upper end of the top frame 31. The lower part of the main shaft 5 is fitted in an inner bushing 51. The inner bushing 51 is fixed to an eccentric sleeve 52. The eccentric sleeve 52 is fitted in an outer bushing 53 mounted to the bottom frame 32. The lower part of the eccentric sleeve 52 is supported by a plain bearing 66, which is mounted to a cylinder tube 63 of the hydraulic cylinder 6. The lower end of the main shaft 5 is supported by a plain bearing 62 mounted to a ram 61 of the hydraulic cylinder 6.

[0028] The gyratory crusher 1 further includes: a main shaft motor 8, which is an electric motor; and a power transmission mechanism 80. The power transmission mechanism 80 transmits rotational power from the main shaft motor 8 to the main shaft 5. As a result, the mantle 13 fixed to the main shaft 5 is driven by the rotational power from the main shaft motor 8 to turn. The main shaft motor 8 is located outside the frame 3. The gyratory crusher 1 includes: a rotation speed sensor 25, which detects a rotation speed of the main shaft motor 8; and a torque sensor 26, which detects an output torque of the main shaft motor 8. The main shaft motor 8 is driven by a motor driver 88.

[0029] The power transmission mechanism 80 transmits motive power from the main shaft motor 8 to the main shaft 5, to which the mantle 13 is fixed. The power transmission mechanism 80 includes: a horizontal shaft 83; a belt-type or chain-type transmission mechanism 82, which transmits rotational power from an output shaft 81 of the main shaft motor 8 to the horizontal shaft 83; the eccentric sleeve 52; and a bevel gear transmission mechanism 84, which transmits rotational power from the horizontal shaft 83 to the eccentric sleeve 52. Upon receiving an output from the main shaft motor 8, the eccentric sleeve 52 rotates, and as a result, the main shaft 5 fitted in the eccentric sleeve 52 turns eccentrically. Consequently, the mantle 13 turns eccentrically relative to the concave 14 whose position is fixed, i.e., the mantle 13 makes precession motion. The degree of opening between the crushing surface of the mantle 13 and the crushing surface of the concave 14 is called "set". The set changes in accordance with a turning position of the main shaft 5 while the mantle 13 is turning eccentrically.

[0030] In the present embodiment, the gyratory crusher 1 includes: the hydraulic cylinder 6, which lifts and lowers the mantle 13 relative to the concave 14 to adjust the set; and the controller 9, which controls the operation of the gyratory crusher 1. As a result of the hydraulic cylinder 6 operating, the mantle 13 is lifted/lowered relative to the concave 14, such that the set at a position where the gap between the two crushing surfaces of the concave 14 and the mantle 13 is narrowest, i.e., the closed set, changes. The hydraulic cylinder 6 also functions as a receiver to receive a crushing pressure applied to the mantle 13.

[0031] The hydraulic cylinder 6 includes: the cylinder tube 63; the ram 61, which slides within the cylinder tube 63; a set sensor 23; an oil tank 67; and the hydraulic circuit 7. The set sensor 23 is, for example, a contact-type or noncontact-type position sensor that detects a position or displacement of the ram 61. The position of the mantle 13 relative to the concave 14 in the height direction is determined from the position or displacement of the ram 61 detected by the set sensor 23. The set is determined from a relative positional relationship between the concave 14 and the mantle 13.

[0032] A hydraulic pressure chamber 65 inside the cylinder tube 63 is demarcated by the inner wall of the cylinder tube 63 and the ram 61. The volume of the hydraulic pressure chamber 65 changes due to a displacement of the ram 61. The hydraulic circuit 7 is connected to the hydraulic pressure chamber 65. Hydraulic oil in the oil tank 67 is supplied to the hydraulic pressure chamber 65 through the hydraulic circuit 7, and as a result, the ram 61 is lifted. Also, the hydraulic oil in the hydraulic pressure chamber 65 is discharged to the oil tank 67 through the hydraulic circuit 7, and as a result, the ram 61 is lowered.

[0033] In the hydraulic circuit 7, an accumulator 72 is connected to a communication pipe 71, which is in communication with the lower part of the hydraulic pressure chamber 65. Not the accumulator 72 but a balance cylinder maybe connected to the communication pipe 71. An oil supply pipe 73 is connected to the communication pipe 71. An oil discharge pipe 74 is connected to the oil supply pipe 73. However, the configuration of the hydraulic circuit 7 is not limited to that described in the present embodiment.

[0034] Interposed in the oil supply pipe 73 are a strainer 75, a gear pump 76, a check valve 77, and a normally closed shut off valve 78, which are sequentially located in this order along, and from the upstream side of, a flow of the hydraulic oil from the oil tank 67 to the hydraulic pressure chamber 65. The gear pump 76 is driven by a pump motor 68. The pump motor 68 is an electric motor, and is driven by a motor driver 69. The hydraulic circuit 7 further includes a pressure sensor 24, which detects the pressure of the hydraulic oil in the hydraulic pressure chamber 65. The pressure sensor 24 may be installed on any of the hydraulic pressure chamber , the communication pipe 71, or the oil supply pipe 73. The oil discharge pipe 74 is connected to the oil supply pipe 73 at a position between the check valve 77 and the shut off valve 78. A normally closed shut off valve 79 is connected to the oil discharge pipe 74.

[0035] [Control system of the crushing system] FIG. 3 is a block diagram showing a schematic configuration of a control system of the crushing system of FIG. 1. As shown in FIG. 3, the controller 9 is connected such that signals are transmittable and receivable between the controller 9 and the load index detector 140, the grain size index detector 130, the feeder 4, and the hydraulic circuit 7. Further, the controller 9 is connected such that a signal is receivable from the set sensor 23. The controller 9 may be connected not only to these components, but also to other components such as sensors. The controller 9 includes a storage 90, which stores a control program and various data.

[0036] The controller 9 includes a computer, for example, a microcontroller, a programmable logic controller, or a personal computer. For example, the controller 9 includes a CPU, a main memory such as a RAM, a communication interface, etc. In accordance with the control program, the controller 9 receives detection signals from various sensors and transmits control commands to respective control targets.

[0037] The functionality of the elements disclosed herein may be implemented using circuitry or processing circuitry which includes general purpose processors, special purpose processors, integrated circuits, ASICs ("Application Specific Integrated Circuits"), conventional circuitry or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors are considered processing circuitry or circuitry as they include transistors and other circuitry therein. In the present specification, the circuitry, units, control blocks or means are hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, units, or means are a combination of hardware and software, the software being used to configure the hardware or processor.

[0038] The controller 9 includes control blocks, specifically, a grain size ratio calculator 91, a target value generator 92, a control command generator 93, and a data obtainer 94. As described above, each of these control blocks is considered processing circuitry. The controller 9 transmits a control command to the feeder 4 or the hydraulic circuit 7 of the gyratory crusher 1. Control commands are generated as a result of arithmetic processing by the control blocks. The controller 9 controls the feeding amount of the to-be-crushed objects fed to the gyratory crusher 1 by transmitting a control command to the electric motor 41 of the feeder 4. Further, by transmitting a control command to the hydraulic circuit 7, the controller 9 controls the operation of the hydraulic cylinder 6 of the gyratory crusher 1. As a result of the operation of the hydraulic cylinder 6 being controlled, the size of the set of the crushing chamber 16 is adjusted. The controller 9 may perform each process by centralized control performed by a single computer, or by distributed control performed by multiple computers in cooperation with each other.

[0039] Part of, or the entirety of, the functionality of the controller 9 or a below-described production amount calculator 170 may be realized by a server, such as a cloud server. The storage 90 may be included in the server, which is, for example, a cloud server. In this case, the various detectors 130, 140, 150, 23, the feeder 4 or the hydraulic circuit 7, which is a control target, and the server are communicably connected via a predetermined communication network.

[0040] [Method of operating the gyratory crusher] Hereinafter, a method of operating the gyratory crusher 1 configured as above is described. At the start of the operation of the gyratory crusher 1, the controller 9 operates the hydraulic circuit 7 to adjust the set, specifically the closed set, to an initial setting value. The initial setting value of the set is preset in accordance with, for example, the grain diameter of to be-crushed objects or crushed product. The controller 9 controls the hydraulic circuit 7 to adjust the set to the initial setting value based on a value detected by the set sensor 23. In a case where the set is greater than the initial setting value, the controller 9 opens the shut off valve 78, and operates the pump motor 68 to supply oil to the hydraulic pressure chamber 65. In a case where the set is less than the initial setting value, the controller 9 opens the shut off valve 78 and the shut off valve 79 to discharge the oil from the hydraulic pressure chamber 65.

[0041] Subsequently, the controller 9 starts the main shaft motor 8 and the feeder 4. As a result of the operation of the feeder 4, the to-be-crushed objects pass through the hopper 2, and are fed into the crushing chamber 16, in which they are crushed between the concave 14 and the mantle 13, which turns eccentrically. The crushed objects are discharged as a crushed product from the bottom of the bottom frame 32. The discharged crushed product is classified by the classifier 110 in terms of grain size, and thereby the products G1 and G2 in predetermined respective grain size ranges are sorted out. The products G Iand G2 thus sorted out are collected as final products.

[0042] While the gyratory crusher 1 as described above is operating, a crushing load varies due to external disturbances, such as the properties of the to-be-crushed objects, the amount of water in the to-be-crushed objects, and a change in the level of the to-be-crushed objects in the hopper 2. The term "crushing load" herein means a load on the output shaft 81 of the main shaft motor 8 due to the crushing of the to-be-crushed objects. If a predetermined load or greater, i.e., an overload, on the output shaft 81 of the main shaft motor 8 occurs, the rotation of the output shaft 81 is locked, and an overload protection circuit starts operating to bring the main shaft motor 8 to an emergency stop. In this respect, the crushing system 100 includes the load index detector 140, which measures a load index Lact that directly or indirectly indicates the crushing load on the gyratory crusher 1. The controller 9 monitors the load index Lact detected during a crushing operation, and controls at least one of the feeding amount of the to-be-crushed objects fed by the feeder 4 or the set of the gyratory crusher 1, such that the load index Lact is within a predetermined reference range that is based on a load index target value Lr.

[0043] The crushing load is represented by the product of the rotation speed and the output torque of the output shaft 81 of the main shaft motor. Accordingly, the crushing load can be measured as the product of the rotation speed detected by the rotation speed sensor 25 and the output torque detected by the torque sensor 26. Since the rotation speed of the output shaft 81 corresponds to the rotation speed of the horizontal shaft 83 and the rotation speed of the eccentric sleeve 52, a rotation speed detected by a rotation speed sensor installed on the horizontal shaft 83 or on the eccentric sleeve 52 may be used instead of the rotation speed detected by the rotation speed sensor 25.

[0044] The crushing load is correlated with the driving current of the main shaft motor 8.

Accordingly, a change in the crushing load can be estimated based on a change in the driving current of the main shaft motor 8. The driving current of the main shaft motor 8 can be measured as a value detected by a current sensor 88a included in the motor driver 88.

[0045] The crushing load is correlated also with electric power consumed by the main shaft motor 8. Accordingly, a change in the crushing load can be estimated based on a change in the electric power consumed by the main shaft motor 8. The electric power consumed by the main shaft motor 8 can be measured as the product of a value detected by the current sensor 88a included in the motor driver 88 and a value detected by a voltage sensor 88b included in the motor driver 88.

[0046] The crushing load is correlated also with the crushing pressure. Accordingly, a change in the crushing load can be estimated based on a change in the crushing pressure. The crushing pressure can be measured as the pressure in the hydraulic pressure chamber 65 detected by the pressure sensor 24.

[0047] From the above, at least one of a value of the product of the rotation speed and the output torque, a value of the driving current of the main shaft motor 8, a value of the electric power consumed by the main shaft motor 8, or a value of the crushing pressure is adoptable as the load index Lact. Then, a sensor corresponding to the adopted load index Lact is selected as the load index detector 140 to detect the load index Lact.

[0048] [Modes of control] The data obtainer 94 includes a load index obtainer 95, a grain size index obtainer 96, and a feeding amount obtainer 97. The load index obtainer 95 obtains, from the load index detector 140, the load index Lact, which directly or indirectly indicates the crushing load on the gyratory crusher 1. The grain size index obtainer 96 obtains, from the grain size index detector 130, the grain size index Pact, which directly or indirectly indicates the production amount of a product in a predetermined grain size range, the product being sorted out by the classification by the classifier 110. The feeding amount obtainer 97 obtains, from the feeding amount detector 150, the feeding amount per unit time of the to-be-crushed objects fed to the gyratory crusher 1. The data obtainer 94 performs, for example, storing of obtained various data in the storage 90 and transmitting of the obtained various data to the function blocks 91, 92, and 93.

[0049] FIG. 4 is a block diagram showing a control block configuration of the controller in the present embodiment. The grain size ratio calculator 91 obtains the grain size index Pact from the crushing system 100, and calculates a grain size ratio Ract. The grain size ratio Ract indicates the production amount of a product Gj as the ratio of the production amount of the product Gj to a predetermined reference production amount, the product Gj being obtained from the objects that have been crushed by the gyratory crusher 1 and being in a predetermined grain size range. The target value generator 92 generates the load index target value Lr based on a grain size ratio deviation AR, which is a result of subtracting the calculated grain size ratio Ract from a grain size ratio target value Rr. The control command generator 93 generates a control command value MV from the load index Lact detected by the load index detector 140 and the load index target value Lr calculated by the target value generator 92. In the crushing system 100, the load index Lact is controlled based on the control command value MV, such that the load index Lact is within the predetermined reference range that is based on the load index target value Lr. Hereinafter, the control blocks are described in detail.

[0050] [Target value generator] FIG. 5 is a block diagram showing a configuration example of the target value generator of FIG. 4. The target value generator 92 includes a subtracter 162, a control gain multiplier 163, a limiter 164, an adder 165, and a retaining circuit 166.

[0051] The subtracter 162 calculates the grain size ratio deviation AR by subtracting, from the grain size ratio target value Rr, the current grain size ratio Ract in the crushing system 100, which is calculated by the grain size ratio calculator 91 as described below.

[0052] The control gain multiplier 163 calculates a load deviation ALr by multiplying the grain size ratio deviation AR by a control gain Kr. In a case where the grain size ratio deviation AR is small, for example, falls within a predetermined range including 0, the grain size ratio deviation AR inputted to the control gain multiplier 163 may be 0, or the load deviation ALr, which is an output from the control gain multiplier 163, may be 0. The target value generator 92 sets the control gain Kr from the detected load index Lact and a correlation between the load index Lact and the grain size ratio Ract. Accordingly, the storage 90 stores, in advance, data that indicates the correlation between the load index Lact and the grain size ratio Ract, the correlation corresponding to the gyratory crusher 1.

[0053] FIG. 6 is a graph showing the correlation between the load index and the grain size ratio in the present embodiment. In the graph of FIG. 6, the horizontal axis represents the load pressure [MPa] corresponding to the load index, and the vertical axis represents the grain size ratio [%]. The graph shows that changes in the grain size ratio have a non-linear correlation with changes in the load pressure. That is, the load pressure in the gyratory crusher 1 can be considered as crushing energy. The lower the load pressure, the less easily the to-be-crushed objects are crushed and the greater the grain size of the product. The higher the load pressure, the more easily the to-be-crushed objects are crushed and the smaller the grain size of the product.

[0054] The disclosers of the present disclosure conducted diligent studies. As a result of the studies, they have found that, as shown in the graph of FIG. 6, changes in the grain size ratio have the above-described correlation with changes in the load pressure. The present disclosure is based on the following finding: by utilizing the correlation, the grain size ratio target value Rr, which can be intuitively set by an operator, can be converted into the load index target value Lr, which is used for load stabilization control to stabilize the crushing load. Specifically, the target value generator 92 generates the load index target value Lr based on the detected load index and the correlation between the load index and the grain size ratio.

[0055] The correlation data stored in advance in the storage 90 may be data of a non-linear correlation such as the one represented by a curve Al illustrated in FIG. 6, or may be data of a linear correlation such as the one represented by a straight line A2, which linearly approximates the correlation in a normal load region of the crushing system 100.

[0056] The correlation data is data in which the load index Lact, which indicates the load pressure when the crushing system 100 is actually in operation, and a predetermined grain size ratio actual value are associated with each other. The predetermined grain size ratio actual value corresponds to the grain size ratio for the grain size ratio target value Rr. For example, in the case of setting the grain size ratio target value Rr by focusing on the ratio of the production amount of the first product G1 to the total production amount, an actual value of the ratio of the production amount of the first product G Ito the total production amount is associated with the load index Lact as a grain size ratio actual value in pre-generated correlation data.

[0057] The target value generator 92 calculates, from the above correlation data stored in advance in the storage 90, the control gain Kr to convert the grain size ratio target value Rr into the load index target value Lr. In the case of using non-linear correlation data, the inclination of a tangent line of the curve Al at the position of the grain size ratio target value Rr is calculated as the control gain Kr. On the other hand, in the case of using linear correlation data, the inclination of the straight line A2 is calculated as the control gain Kr. The calculated control gain Kr is set as the control gain Kr to be multiplied by a grain size ratio deviation correction value ARc by the control gain multiplier 163. According to this configuration, since a value relating to the grain size ratio is converted into a value relating to the load index by using the correlation stored in advance in the storage 90, the load index target value Lr can be generated by simple arithmetic processing.

[0058] The limiter 164 limits the load deviation ALr, which is an output from the control gain multiplier 163, to fall within a predetermined limited range E. For example, in a case where the load deviation ALr is greater than the upper limit value of the limited range E, the upper limit value being greater than 0, the limiter 164 outputs the upper limit value as a load deviation correction value ALrc. In a case where the load deviation ALr is less than the lower limit value of the limited range E, the lower limit value being less than 0, the limiter 164 outputs the lower limit value as the load deviation correction value ALrc. In a case where the load deviation ALr is within the limited range E, the limiter 164 outputs the load deviation ALr as the load deviation correction value ALrc. With the limiter 164 thus configured, a rapid change in the load index target value Lr is suppressed.

[0059] The limited range E may be made changeable in accordance with the detected load index Lact. As shown in FIG. 5, in the correlation indicated by the curve Al, when the load pressure is low, the degree of a change in the grain size ratio in relation to a change in the load pressure is great, whereas when the load pressure is high, the degree of a change in the grain size ratio in relation to a change in the load pressure is small. Accordingly, in the case of calculating the load index target value Lr by using non-linear correlation data, if the current load index Lact is small, the limited range E may be set as a small range, whereas if the current load index Lact is great, the limited range E may be set as a great range. In this manner, the limited range E can be suitably set in accordance with a change rate of the grain size ratio.

[0060] Although the manner of changing the limited range E is not particularly limited, for example, in a case where the load index Lact is less than a predetermined reference value, the limited range E is set to a first range, whereas in a case where the load index Lact is greater than or equal to the predetermined reference value, the limited range E is set to a second range, which is included in the first range, but narrower than the first range. By setting two or more reference values, the limited range E can be set to three or more ranges. Also, for example, the upper limit value or the lower limit value of the limited range E corresponding to the load index Lact may be calculated by using a predetermined mathematical function. In this case, the magnitude of the limited range E changes continuously in accordance with changes in the load index Lact.

[0061] In the case of calculating the load index target value Lr by using a linear correlation, such as the one indicated by the straight line A2, the magnitude of the limited range E of the limiter 164 may be fixed.

[0062] The retaining circuit 166 retains, for a predetermined time, the load index target value Lr outputted from the target value generator 92. The adder 165 adds the load deviation correction value ALrc outputted from the limiter 164 to a past load index target value Lrp retained by the retaining circuit 166. That is, the target value generator 92 calculates the load deviation correction value ALrc as a change amount of a target value for the past load index target value Lrp, and by adding the load deviation correction value ALrc to the past load index target value Lrp, generates a new load index target value Lr.

[0063] [Control command generator] The control command generator 93 generates the control command value MV for the crushing system 100 based on the load index target value Lr generated by the target value generator 92 and the load index Lact detected by the load index detector 140.

[0064] FIG. 7 is a block diagram showing a configuration example of the control command generator of FIG. 4. The control command generator 93 includes a subtracter 168 and a control calculator 169. The subtracter 168 calculates a load deviation actual value AL by subtracting the current load index Lact from the load index target value Lr. The load index Lact inputted to the subtracter 168 may be the load index Lact after noise is removed therefrom by a predetermined filter.

[0065] The control calculator 169 applies a predetermined control algorithm to the load deviation actual value AL to generate the control command value MV. For example, the control calculator 169 includes a PID controller including a proportional element, an integral element, and a differential element. Alternatively, the control calculator 169 may include, for example, a P controller including a proportional element, a PI controller including a proportional element and an integral element, or aPD controller including a proportional element and a differential element.

[0066] The control command generator 93 outputs the control command value MV, which is generated in accordance with the aforementioned control algorithm. In a case where the load deviation actual value AL is small, for example, falls within a predetermined range including 0, the load deviation actual value AL inputted to the control calculator 169 may be 0, or the control calculator 169 may output the same control command value MV as the previous control command value MV. The control command generator 93 may further include a limiter that limits the control command value MV generated by the control calculator 169 to fall within a predetermined limited range.

[0067] The controller 9 operates a control target in response to the control command value MV generated by the control command generator 93. In a case where the control target is the hydraulic circuit 7, the amount of hydraulic oil supplied to the hydraulic cylinder 6 is controlled in accordance with the control command value MV, and also, the size of the set of the crushing chamber 16 is adjusted. In a case where the control target is the feeder 4, the feeding amount of the to-be-crushed objects fed by the conveyor 40 to the gyratory crusher 1 is controlled in accordance with the control command value MV.

[0068] [Grain size ratio calculator] The grain size ratio calculator 91 calculates the grain size ratio Ract based on the grain size index Pact detected by the grain size index detector 130. The grain size ratio Ract is defined as a value that indicates the production amount of a product Gj as the ratio of the production amount of the product Gj to a predetermined reference production amount, the product Gj being obtained from the objects that have been crushed by the gyratory crusher 1 and being in a predetermined grain size range.

[0069] First, as one example, a mode of control of the crushing system 100 is illustratively described, in which the total production amount of the products Gj, i.e., the feeding amount, is the reference production amount, and the ratio of the production amount of the first product GI to the reference production amount is the grain size ratio Ract to be controlled.

[0070] In this example, the first electric power measurer 131 is the grain size index detector 130. As described above, the first electric power measurer 131 measures the electric power P1 supplied to the electric motor 118, which drives the first transport conveyor 115, which transports the first product G1, which is sorted out by the classification by the classifier110.

[0071] FIG. 8 is a graph showing a relationship between the electric power supplied to the electric motor of the transport conveyor and a transportation amount per unit time of the product transported by the transport conveyor. In actual equipment, the product in a predetermined amount was transported by the transport conveyor, and the electric power supplied to the electric motor at the time and an actual transportation amount at the time were measured. Combination data of the measured electric power and the measured transportation amount are plotted on the graph of FIG. 8. Further, in the graph of FIG. 8, a straight line is illustrated, which approximates multiple plotted positions that were obtained when the transportation amount was changed.

[0072] The first transport conveyor 115 transports the first product G1 at a constant speed. When the first product G1 is transported on the first transport conveyor 115, a load on the electric motor 118, which drives the first transport conveyor 115, increases. In order to operate the first transport conveyor 115 at a constant speed, it is necessary to increase the first electric power P1 supplied to the electric motor 118. In the example of FIG. 8, a change in the transportation amount per unit time in relation to a change in the first electric power P1 that may be supplied to the electric motor 118 has a linear property as indicated by the approximation straight line in FIG. 8.

[0073] By utilizing such a linear property, the transportation amount per unit time of the first product G Itransported by the first transport conveyor 115, i.e., the production amount per unit time of the first product G1 in the first grain size range, can be determined from the first electric power P1 supplied to the electric motor 120, which drives the first transport conveyor 115. Accordingly, in this example, the grain size ratio calculator 91 obtains the first electric power P1 as the grain size index Pact.

[0074] FIG. 9 is a block diagram showing a configuration example of the grain size ratio calculator of FIG. 5. As shown in FIG. 9, the grain size ratio calculator 91 includes the production amount calculator 170, a filter 171, an average value calculator 172, and a calculation performer 173. The storage 90 stores in advance therein a correlation between the electric power supplied to the electric motor 120 and the transportation amount by the first transport conveyor 115 per unit time. The crushing system 100 of the present embodiment includes the gyratory crusher 1, the first transport conveyor 115, the first electric power measurer 131, and the controller 9, which functions as a production amount detector. The crushing system 100 of the present embodiment includes a production amount detection system to detect the production amount of the first product G1 produced by the gyratory crusher 1. Thecontroller9 functioning as the production amount detector includes the storage 90 and the production amount calculator 170.

[0075] The production amount calculator 170 retrieves the corresponding correlation from the storage 90, and calculates the transportation amount corresponding to the first electric power P1, which is obtained as the grain size index Pact, as the production amount of the first product GI, i.e., as a subject product production amount Sact. According to this configuration, by measuring the first electric power P1 supplied to the electric motor 118, which drives the first transport conveyor 115, the transportation amount by the first transport conveyor 115 can be calculated as the production amount of the product transported by the first transport conveyor 115, by using the correlation between the first electric power P1 and the transportation amount by the first transport conveyor 115, the correlation being stored in the storage 90. Therefore, the production amount of the product transported by the first transport conveyor 115 can be readily calculated at low cost without having to, for example, equip thefirst transport conveyor 115 with a belt scale capable of weighing the transportation amount or additionally install means for detecting the transportation amount.

[0076] Further, the grain size ratio calculator 91 obtains the value Pall detected by the feeding amount detector 150. As described above, the feeding amount detector 150, for example, detects the fourth electric power P4 supplied to the electric motor 41, which drives the conveyor 40 of the feeder 4. Similar to the case of calculating the subject product production amount Sact, the production amount calculator 170 retrieves the corresponding correlation from the storage 90, and calculates the transportation amount corresponding to the fourth electric power P4 as the feeding amount to the gyratory crusher 1. In this example, the grain size ratio calculator 91 sets the total production amount of the first product GI, the second product G2, and the third product G3 as a reference production amount Sall. Further, in the present embodiment, the total production amount can be considered equal to the feeding amount to the gyratory crusher 1. Accordingly, in this example, the grain size ratio calculator 91 uses the calculated feeding amount as the reference production amount Sall.

[0077] The correlation used when determining the feeding amount may be the same as or different from the correlation used when determining the production amount of thefirst product GI. That is, in cases where the first transport conveyor 115 and the conveyor 40 of the feeder 4 share the same characteristics, for example, in a case where they are the same in terms of transportation capability or in terms of size, one common correlation for both the conveyors 40 and 115 maybe stored in the storage 90. Alternatively, multiple correlations including a correlation corresponding to the conveyor 40 of the feeder 4 and a correlation corresponding to the first transport conveyor 115 may be stored in the storage 90.

[0078] The grain size index detector 130 continuously, or at predetermined timings, detects the grain size index Pact. Accordingly, the subject product production amount Sact obtained by the production amount calculator 170 is data that may change in accordance with elapse of time. Similarly, the feeding amount detector 150 continuously, or at predetermined timings, detects the value Pall indicating the feeding amount. Accordingly, the feeding amount obtained by the production amount calculator 170, i.e., the reference production amount Sall, is data that may change in accordance with elapse of time.

[0079] The filter 171 smooths the subject product production amount Sact and the reference production amount Sall. For example, the filter 171 includes a moving average filter. The filter 171 removes external disturbances that are due to non-uniformity in the product Gj, for example, non-uniformity in the size or compressive hardness of the product Gj.

[0080] After the subject product production amount Sact and the reference production amount Sall are filtered to be afiltered subject product production amount Sfact and afiltered reference production amount Sfall, the average value calculator 172 calculates, for each predetermined unit period, an average value of each of the filtered subject product production amount Sfact and the filtered reference production amount Sfall. For example, the average value calculator 172 extracts each predetermined unit period from a period in which temporal changes in the filtered subject product production amount Sfact are within a reference range, and calculates an average value of the filtered subject product production amount Sfact in each extracted unit period. That is, the average value calculator 172 calculates, for each unit period, an average value of the filtered subject product production amount Sfact while excluding periods in which temporal changes in the filtered subject product production amount Sfact are steep. The average value calculator 172 calculates an average value of the filtered reference production amount Sfall in the same manner.

[0081] The calculation performer 173 calculates the grain size ratio Ract based on an average subject product production amount Svact and an average reference production amount Svall, which are calculated by the average value calculator 172, the grain size ratio Ract indicating the production amount of the third product G3 as the ratio thereof to the reference production amount.

[0082] The calculation performer 173 calculates, as the grain size ratio Ract, the ratio of the average subject product production amount Svact to an average feeding amount. That is, the grain size ratio Ract is calculated by using an equation (1) below.

[0083] [Math. 1]

Svact Ract = x100[%] • • (1) Svall

[0084] The calculated grain size ratio Ract is inputted to the target value generator 92. The above equation (1) can be generalized into an equation (2) shown below.

[0085] [Math. 2]

Ract=- k1 Sl+ k 2S2+k3 S3 (2) k4S1+k5S2+k S3+k7S4+k S5

Si: the production amount of the first product G1 S2: the production amount of the second product G2 S3: the production amount of the third product G3 S4: feeding amount S5: the transportation amount by the middle conveyor ki = 0 or 1 (i = 1, 2,..., 8)

[0086] The value of ki is switched between 0 and 1 depending on the grain size ratio Ract that is focused on. Also in the equation (2), the production amounts Si, S2, S3 and the feeding amounts S4 and S5 are values outputted from the average value calculator 172. The above example, i.e., the grain size ratio Ract indicating the production amount of the first product G Ias the ratio of the production amount of the first product GIto the feeding amount, corresponds to a case where both ki and k 7 in the equation (2) are 1, and the other coefficients ki are 0.

[0087] In the above example, the feeding amount of the to-be-crushed objects is the reference production amount, and the ratio of the production amount of the first product G Ito the reference production amount is the grain size ratio Ract to be controlled. As the reference production amount, i.e., as the value Pall detected by the feeding amount detector 150, not the fourth electric power P4 supplied to the electric motor 41, which drives the conveyor 40 of the feeder 4, but the fifth electric power P5 supplied to the electric motor 114, which drives the middle conveyor 113, maybe used. That is, in the above example, in the equation (2), instead of setting k7 to 1, k8 may be set to 1.

[0088] Alternatively, the production amount calculator 170 may calculate the production amount of the first product G1, the production amount of the second product G2, and the production amount of the third product G3, and a value obtained by adding up these production amounts may be used as the reference production amount Sall. That is, in the above example, in the equation (2), instead of setting k 7 to 1, k4, k5, and k6 may be set to 1.

[0089] The above description gives the example in which the feeding amount of the to-be crushed objects is the reference production amount, and the ratio of the production amount of the first product G Ito the reference production amount is the grain size ratio Ract to be controlled. However, various grain size ratios are adoptable as the grain size ratio Ract depending on a grain size ratio target value set by an operator, i.e., depending on a grain size ratio to be monitored.

[0090] For example, the subject product production amount Sact may be the production amount of the second product G2, or may be a total value of the production amounts of the first product G Iand the second product G2. For example, in the equation (2), k 2 and k4 may be set to 1, and the other coefficients ki may be set to 0. Alternatively, ki, k2 , and k4 may be set to 1, and the other coefficients ki may be set to 0. Further alternatively, the subject product production amount Sact may be the production amount of the third product G3. For example, in the equation (2), k3 and k 4 may be set to 1, and the other coefficients ki may be set to 0. In a case where the subject product production amount Sact is the production amount of the third product G3, the grain size ratio Ract indicates the proportion, to the feeding amount, of the crushed objects that are fed to the gyratory crusher 1 again, i.e., indicates the return ratio of the crushed objects. Also in these variations, instead of setting k4 to 1, k5 may be set to 1, or ki, k2 ,

and k3 may be set to 1.

[0091] The grain size ratio Ract may be the ratio of the production amount in one of multiple classification ranges to the total production amount in the multiple classification ranges. For example, the grain size ratio Ract may be the ratio of the production amount of the first product G Ior the second product G2 to a total value of the production amounts of the first product G Iand the second product G2. For example, in the equation (2), ki or k2 as well as k4 and k 5 may be set to 1, and the other coefficients ki may be set to 0.

[0092] As described above, among the coefficients ki in the equation (2), by selecting a suitable combination of the coefficients to be 1 and the coefficients to be 0, the grain size ratio calculator 91 can calculate a desired grain size ratio Ract based on the product Gj that is focused on by the operator. The grain size ratio target value Rr may be preset corresponding to selections of the coefficients ki. Specifically, the storage 90 may store preset values of the grain size ratio target value Rr corresponding to expected combinations of the coefficients ki. Among these preset values, a preset value corresponding to an operator's selection of the coefficients ki is retrieved, and based on the retrieved preset value, the operator may make adjustments to achieve a desired grain size ratio target value Rr.

[0093] Similar to the production amount of the first product GI, the production amount calculator 170 can calculate the production amount of the second product G2, the production amount of the third product G3, and the transportation amount of the middle conveyor 113 based on the electric power supplied to the electric motors 119, 120, and 114, which drive the corresponding conveyors 116, 117, and 113, respectively. At the time, in a case where the transport conveyors 115, 116, 117 with the respective electric motors 118, 119, 120 are, for example, the same in terms of transportation capability or in terms of size, one common correlation for the transport conveyors 115, 116, and 117 may be stored in the storage 90. Alternatively, multiple correlations corresponding to the respective transport conveyors 115, 116, and 117 may be stored in the storage 90.

[0094] Whichever grain size range the product Gj that is focused on is in, the production amount of the product Gj is calculated by the production amount calculator 170 in the same manner. The production amounts of multiple types of products Gj obtained from the gyratory crusher 1 can be readily calculated, which makes it possible to readily check the production balance between the multiple types of products Gj.

[0095] [Advantageous effects of the present embodiment] According to the above-described configuration, at least one of the gyratory crusher 1 or the feeder 4 is controlled such that the load index Lact is within a reference range that is based on the load index target value Lr. In this manner, a load variation within a short time is suppressed, which makes it possible to stably operate the crushing system 100. Further, according to the above configuration, the load index target value Lr is calculated by using the grain size ratio Ract, which indicates the production amount Sact of the product Gj in the grain size range that is focused on as the ratio thereof to the predetermined reference production amount Sall, and the correlation between the load index Lact and the grain size ratio Ract.

[0096] Accordingly, the operator can intuitively set a control target value for the crushing system 100 based on the production amount Sact of the product in the grain size range that is focused on. The production amount Sact of the product is obtained from averaging for a relatively long time. Therefore, by generating such a load index target value Lr as to bring the grain size ratio Ract, which is obtained based on the production amount Sact of the product that is focused on, to the grain size ratio target value Rr, the crushing system 100 can be operated stably with an optimal production balance.

[0097] From the above, a target value for achieving a desired production amount of the product Gj in a predetermined grain size range can be set intuitively, and the gyratory crusher 1 can be controlled stably to achieve the desired production amount.

[0098] Further, according to the above embodiment, the grain size index Pact, which directly or indirectly indicates the production amount of the product Gj in a predetermined grain size range, is detected, and by using the grain size index Pact, the grain size ratio Ract is calculated. The production balance between the products Gj in the respective grain size ranges can be readily evaluated by measuring or estimating the production amount of each product Gj that has been sorted out, instead of directly measuring the grain size of each product Gj. Further, the grain size ratio Ract of the product Gj in the grain size range that is focused on can be readily calculated. Still further, at the transport conveyors 115, 116, and 117, which transport the products Gj in the respective predetermined grain size ranges, the transportation amount of each product Gj per unit time is used as the production amount of the product Gj in the calculation of the grain size ratio Ract. Therefore, the product Gj that is focused on can be detected without requiring additional installation of a weigher.

[0099] [Simulation results] FIG. 10 illustrates graphs showing results of simulation of a control mode based on the present embodiment. In FIG. 10, the lower graph shows temporal changes in load pressure, whereas the upper graph shows temporal changes in grain size ratio. In the simulation of this example, at a time TI, the grain size ratio target value Rr is changed from a first target value Rr to a second target value Rr2 less than the first target value Rrl.

[0100] As shown in FIG. 10, due to the change in the grain size ratio target value Rr, the load index target value Lr after the time Ti is higher than before the time T1. The load index target value Lr changes in a stepwise manner for the reason that the limiter 164 limits a sudden change in the load index target value Lr. Asa result of the crushing system 100 being controlled by the load index target value Lr, the load index Lact detected from the gyratory crusher 1 changes to follow the load index target value Lr. Consequently, the grain size ratio Ract of the product Gj obtained by crushing the to-be-crushed objects by the gyratory crusher 1 also changes in a manner to follow the grain size ratio target value Rr. Thus, in the present embodiment, by performing load pressure control using the grain size ratio target value Rr, a desired grain size ratio is obtained, which is shown also in the present simulation.

[0101] [Variations] Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above embodiment, and various improvements, alterations, and modifications can be made to the above embodiment without departing from the scope of the present disclosure.

[0102] For example, in the above-described embodiment, the grain size index detector 130 is configured such that it can detect the grain size index of each of the first product G1, the second product G2, and the third product G3. Alternatively, the grain size index detector 130 may be configured such that it can detect the grain size index of at least one of these products. That is, the crushing system 100 need not include means for detecting grain size indexes that are not used for calculating the grain size ratio Ract that is focused on. For example, in a case where the grain size ratio Ract that is focused on is the return ratio, it will suffice if the grain size index detector 130 can detect the grain size index of the third product G3. In this case, in the above-described embodiment, it will suffice if the crushing system 100 includes the third electric power measurer 133 as the grain size index detector 130, and the crushing system 100 need not include the first electric power measurer 131 and the second electric power measurer 132. Similarly, in a case where the grain size ratio Ract that is focused on is the grain size ratio Ract of either one of the first product GIor the second product G2, it will suffice if the crushing system 100 includes either one of the first electric power measurer 131 or the second electric power measurer 132 as the grain size index detector 130.

[0103] Further, the above embodiment illustratively describes a mode in which the grain size index detector 130 detects, as the grain size index Pact, the electric power supplied to each of the electric motors 118, 119, and 120, which drive the respective transport conveyors 115, 116, and 117, which transport the respective products Gj, thereby calculating the production amounts of the respective products Gj. However, the grain size index detection mode is not limited to this example.

[0104] For example, each of the transport conveyors 115, 116, and 117 may be a belt scale that can detect a transportation amount per unit time. In this case, a measurement value of the belt scale is detected as a grain size index. That is, the grain size index is the transportation amount of the product Gj per unit time, i.e., the production amount of the product Gj. Further, a camera may be installed on the transport surface of each of the transport conveyors 115, 116, and 117, and image processing may be performed on an image captured by the camera to detect, as a grain size index, the transportation amount of the product Gj per unit time, i.e., the production amount of the product Gj. For example, the cross-sectional area of the transported product is determined from an image of the product captured by the camera, and the transportation amount of the product can be estimated from the cross-sectional area and the transporting speed. Also, variations similar to those for the grain size index are adoptable for the value detected by the feeding amount detector 150. Specifically, at each of the conveyor 40 of the feeder 4 and the middle conveyor 113, the feeding amount may be calculated from a measurement value of a belt scale or from a value detected by image processing.

[0105] Alternatively, the grain size index detector 130 may be eliminated. For example, the objects that have been crushed by the gyratory crusher 1 and that have not yet been classified by the classifier 110, i.e., mixed products of the first product GI, the second product G2, and the third product G3, may be subjected to image capturing by a camera, and image processing may be performed on the captured image. Then, the ratio of the product Gj in a predetermined grain size range to the entire mixed products may be estimated from the image-processed captured image. That is, the grain size ratio calculator 91 may directly obtain a desired grain size ratio Ract from the captured image. In this case, the camera may be installed on the transport surface of the middle conveyor 113, for example.

[0106] In order to calculate the grain size ratio Ract by using no grain size index, the grain size ratio calculator 91 may calculate, from the correlation between the load index Lact and the grain size ratio Ract and the load index Lact detected by the load index detector 140, the grain size ratio Ract corresponding to the load index Lact. For example, the grain size ratio calculator 91 may retrieve the linear correlation indicated by the straight line A2 shown in FIG. 6, and may output the grain size ratio Ract corresponding to the detected load index Lact in the correlation. According to this configuration, the grain size ratio Ract can be calculated without additionally installing the grain size index detector 130.

[0107] The above embodiment also illustratively describes a mode in which the control gain Kr used by the target value generator 92 is calculated from the correlation stored in advance in the storage 90 and the load index Lact detected by the load index detector 140. However, this is merely a non-limiting example. As an alternative example, the storage 90 may store a history of the load index Lact and the grain size ratio Ract, and the target value generator 92 may calculate the correlation by calculating, from two or more past combinations of the load index Lact and the grain size ratio Ract, a change rate of the grain size ratio Ract in relation to the load index Lact, and may calculate the control gain Kr by using the calculated correlation.

[0108] For example, similar to the graph of FIG. 6, in a case where the horizontal axis represents the load index indicating the load pressure, and the vertical axis represents the grain size ratio, a straight line connecting between first coordinates Qi (Lal, Ral) indicating a combination of a load index Lal and a grain size ratio Ral at a past first time point and second coordinates Q2 (La2, Ra2) indicating a combination of a load index La2 and a grain size ratio Ra2 at a past second time point is a straight line indicating the correlation of the grain size ratio with the load index. Alternatively, a straight line or a curve that approximates three or more sets of coordinates at three or more past time points may be used as the correlation.

[0109] By using the correlation thus obtained, the target value generator 92 may calculate the control gain Kr. That is, in relation to the detected load index Lact, the target value generator 92 may calculate the inclination of the correlation or the inclination of the tangent line thereof, as the control gain Kr. According to this configuration, by calculating the control gain Kr from actual measurement values of the load index and the grain size ratio, characteristics of the gyratory crusher 1 during its actual operation can be extracted, which makes it possible to generate the load index target value Lr with higher precision.

[0110] Although the above embodiment illustratively describes the crushing system 100 including the hydraulic gyratory crusher 1, the gyratory crusher 1 is not limited thereto. For example, a mechanical gyratory crusher is also applicable as the gyratory crusher 1.

[0111] FIG. 11 shows a schematic configuration of another example of a gyratory crusher applied to the crushing system of FIG. 1. In FIG. 11, the same components as those of the hydraulic gyratory crusher 1of FIG. 2 are denoted by the same reference signs as those used in FIG. 2, and the description of such components is omitted.

[0112] As shown in FIG. 11, similar to the hydraulic gyratory crusher 1, a gyratory crusher 1A includes: the hopper 2, which feeds the to-be-crushed objects to the crushing chamber 16; the feeder 4, which feeds the to-be-crushed objects to the hopper 2; the mantle 13 and the concave 14, between which the to-be-crushed objects dropped from the hopper 2 are caught and crushed; the main shaft motor 8, which is a driver to drive the turning of the main shaft 5, to which the mantle 13 is fixed; the power transmission mechanism 80, which transmits rotational power from the main shaft motor 8 to the mantle 13; and the controller 9.

[0113] Unlike the hydraulic gyratory crusher 1, the mechanical gyratory crusher 1A shown in FIG. 11 does not include the hydraulic circuit 7 and the hydraulic cylinder 6 for controlling the set of the crushing chamber 16 through the hydraulic circuit 7. That is, in the gyratory crusher 1A, the set is mechanically maintained.

[0114] In the gyratory crusher 1A, the set is mechanically adjustable. Accordingly, the gyratory crusher 1A includes: an internal thread 31a on the inner peripheral surface of the top frame 31; and an external thread 35a on the outer peripheral surface of a concave support 35. The internal thread 31a and the external thread 35a are screwed together. The concave support includes external teeth 35b, which mesh with a driving gear 45. The driving gear 45 rotates by receiving rotational power from an electric motor 46. The electric motor 46 is supported by the top frame 31. The operation of the electric motor 46 is controlled by a motor driver 47 connected to the controller 9.

[0115] When the driving gear 45 rotates, the concave support 35 rotates relative to the top frame31. When the concave support 35 rotates, due to the internal thread 31a of the top frame 31 and the external thread 35a of the concave support 35 being screwed together, the concave support 35 is lifted/lowered relative to the top frame 31, and thereby the set is changed. However, in the mechanical gyratory crusher 1A, the set is not changed during a crushing operation.

[0116] A contact-type or noncontact-type set sensor 23A, which detects a displacement of the concave support 35 relative to the top frame 31, is located on the top frame 31 or the concave support 35. The controller 9 can determine the set from a value detected by the set sensor 23A. Based on the value of the set detected by the set sensor 23A, the controller 9 operates the electric motor 46.

[0117] The mantle 13 is mounted to the mantle core 12 fixed to the upper part of the main shaft 5. The main shaft 5 is located inside the frame 3 in a state where the center axis of the main shaft 5 is inclined relative to the vertical direction. The lower part of the main shaft 5 is fitted in the inner bushing 51. The inner bushing 51 is fixed to the eccentric sleeve 52. The eccentric sleeve 52 is fitted in the outer bushing 53 mounted to the bottom frame 32. The lower part of the eccentric sleeve 52 is supported by the plain bearing 66. The mantle core 12 is supported by a thrust bearing (static pressure bearing) 55 on the bottom frame 32. Lubricating oil forms an oil film between the mantle core 12 and the thrust bearing 55. A lubricating circuit 7A of the thrust bearing 55 includes a pressure sensor 24A, which detects the hydraulic supply pressure of the lubricating oil. When crushing pressure is applied to the mantle 13, a higher pressure is necessary to supply the lubricating oil into between the mantle core 12 and the thrust bearing 55, and the hydraulic pressure of the lubricating oil supplied to the thrust bearing 55 increases. Accordingly, the hydraulic supply pressure at the thrust bearing 55, which is detected by the pressure sensor 24A, is a measurement value that indirectly indicates the crushing load, and is usable as the load index Lact.

[0118] Similar to the above-described gyratory crusher 1, the gyratory crusher 1A configured as above includes the load index detector 140, which detects the load index Lact, which directly or indirectly indicates the crushing load. The controller 9 monitors the load index Lact detected during a crushing operation, and controls the feeding amount of the to-be crushed objects fed by the feeder 4, such that the load index Lact is within a predetermined reference range that is based on the load index target value Lr.

[0119] The above embodiment illustratively describes the crushing system 100 as a production apparatus to produce products. However, the production amount detection system and production amount detection method are applicable not only to the crushing system 100, but also to other production apparatuses, so long as they produce a product that is transportable by a transport conveyor. Examples of such a production apparatus include a cement production plant in which cement raw meal is fired to produce clinker as a product. Further, the product to be detected may be, for example, one to be discarded thereafter. For example, the production apparatus may include ash handling equipment to handle ash that is discharged from, for example, a refuse treatment facility. The product produced by the production apparatus may be only one type of product.

[0120] [Summary of the present disclosure]

[Item 1] A controller of a crushing system according to one aspect of the present disclosure is a controller of a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the controller including processing circuitry. The processing circuitry: obtains a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculates a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generates the load index target value based on the obtained load index and a correlation between the load index and the grain size ratio; and generates a control command value from the load index and the load index target value. The controller controls at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.

[0121] According to the above configuration, at least one of the gyratory crusher or the feeder is controlled such that the load index is within the reference range that is based on the load index target value. In this manner, a load variation within a short time is suppressed, which makes it possible to stably operate the crushing system. Further, according to the above configuration, the load index target value is calculated by using the grain size ratio, which indicates the production amount of the product in the grain size range that is focused on as the ratio thereof to the predetermined reference production amount, and the correlation between the load index and the grain size ratio.

[0122] Accordingly, the operator can intuitively set a control target value for the crushing system based on the production amount of the product in the grain size range that is focused on. The production amount of the product is obtained from averaging for a relatively long time. Therefore, by generating such a load index target value as to bring the grain size ratio, which is obtained based on the production amount of the product that is focused on, to the grain size ratio target value, the crushing system can be operated stably with an optimal production balance.

[0123] From the above, a target value for achieving a desired production amount of the product in the predetermined grain size range can be set intuitively, and the gyratory crusher can be controlled stably to achieve the desired production amount.

[0124] [Item 2] In the controller of item 1, the crushing system may include a classifier that performs classification to classify, in terms of grain size, the objects that have been crushed by the gyratory crusher, and the processing circuitry may: obtain a grain size index that directly or indirectly indicates the production amount of the product in the predetermined grain size range, the product being sorted out by the classification by the classifier; and calculate the grain size ratio by using the grain size index.

[0125] According to the above configuration, the grain size index, which directly or indirectly indicates the production amount of the product in the predetermined grain size range, is detected, and by using the grain size index, the grain size ratio is calculated. In this manner, the grain size ratio of the product in the grain size range that is focused on can be readily calculated.

[0126] [Item 3] In the controller of item 2, the crushing system may include a transport conveyor located downstream of the classifier, wherein the transport conveyer transports the product that is in the predetermined grain size range and that has been sorted out, and the processing circuitry may calculate the grain size ratio by using, as the production amount of the product in the predetermined grain size range, a transportation amount per unit time of the product transported by the transport conveyor.

[0127] According to the above configuration, the transportation amount per unit time of the product in the predetermined grain size range at the transport conveyor transporting the product is used, as the production amount of the product, in the calculation of the grain size ratio. Therefore, the production amount of the product that is focused on can be detected without requiring additional installation of a weigher.

[0128] [Item 4] In the controller of item 3, the processing circuitry may obtain, as the grain size index, electric power supplied to an electric motor that drives the transport conveyor. According to this configuration, by obtaining the electric power supplied to the electric motor that drives the transport conveyor, the transportation amount of the transport conveyor can be calculated. Therefore, according to the above configuration, the transportation amount by the transport conveyor per unit time can be readily calculated at low cost without having to, for example, configure the transport conveyor as a belt scale capable of weighing the transportation amount or additionally install means for detecting the transportation amount.

[0129] [Item 5] In the controller of item 3 or 4, the processing circuitry may: obtain a feeding amount per unit time of the objects to be crushed that are fed to the gyratory crusher; and calculate, as the grain size ratio, a proportion of the transportation amount by the transport conveyor to the feeding amount.

[0130] [Item 6] In the controller of item 1, the processing circuitry may calculate, from the correlation and the obtained load index, the grain size ratio corresponding to the load index. According to this configuration, the grain size ratio can be calculated without additionally installing a grain size index detector.

[0131] [Item 7] In the controller of any one of items 1 to 6, the processing circuitry may: set a control gain from the obtained load index and the correlation, and generate the load index target value based on the control gain and a grain size ratio deviation that is obtained by subtracting the grain size ratio from a predetermined grain size ratio target value. Accordingly, since the load index target value is generated from the grain size ratio deviation by using the control gain, the grain size ratio target value can be readily converted into the load index target value with a simple configuration.

[0132] [Item 8] The controller of item 7 may include a storage that stores the correlation, and the processing circuitry may calculate the control gain from the obtained load index and the correlation that is stored in advance in the storage. According to this configuration, since a value relating to the grain size ratio is converted into a value relating to the load index by using the correlation stored in advance in the storage, the load index target value can be generated by simple arithmetic processing.

[0133] [Item 9] The controller of item 7 may include a storage that stores the obtained load index and a history of the calculated grain size ratio, and the processing circuitry may calculate the correlation by calculating, from two or more past combinations of the load index and the grain size ratio, a change rate of the grain size index in relation to the load index, and may calculate the control gain from the obtained load index and the calculated correlation. According to this configuration, by calculating the control gain from actual measurement values of the load index and the grain size ratio, characteristics of the gyratory crusher during its actual operation can be extracted, which makes it possible to generate the load index target value with higher precision.

[0134] [Item 10] In the controller of any one of items 7 to 9, the processing circuitry may include: a control gain multiplier that multiplies the grain size ratio deviation by the control gain; and a limiter that limits an output from the control gain multiplier to fall within a predetermined limited range. The limited range may be set in accordance with the obtained load index. In this manner, the limited range can be suitably set in accordance with the change rate of the grain size ratio.

[0135] [Item 11] A crushing system according to another aspect of the present disclosure includes: a gyratory crusher; a feeder that feeds objects to be crushed to the gyratory crusher; and the controller of any one of items I to 10.

[0136] [Item 12] In the crushing system of item 11, the gyratory crusher may include: a mantle fixed to a main shaft that turns eccentrically; and a concave including therein a crushing chamber in which the objects to be crushed are caught and crushed between the mantle and the concave. A set between the mantle and the concave may be mechanically maintained. The controller may control a feeding amount of the objects to be crushed that are fed to the gyratory crusher.

[0137] [Item 13]

In the crushing system of item 11, the gyratory crusher may include: a mantle fixed to a main shaft that turns eccentrically; a concave including therein a crushing chamber in which the objects to be crushed are caught and crushed between the mantle and the concave; and a hydraulic cylinder that applies, to the mantle or the concave, hydraulic force against crushing force, such that a set between the mantle and the concave is maintained. The controller may control at least one of a feeding amount of the objects to be crushed that are fed to the gyratory crusher or a size of the set.

[0138] [Item 14] A control method according to yet another aspect of the present disclosure is a method of controlling a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the method including: detecting a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculating a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generating the load index target value based on the detected load index and a correlation between the load index and the grain size ratio; and generating, from the load index and the load index target value, a control command value to control at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.

[0139] [Item 15] A production amount detector according to yet another aspect of the present disclosure is a production amount detector in a production apparatus that produces a predetermined product by performing a predetermined process on a raw material fed into the production apparatus, the production apparatus including a transport conveyor that transports the produced product, the production amount detector including: a storage that stores in advance therein a correlation between electric power supplied to an electric motor that drives the transport conveyor and a transportation amount per unit time by the transport conveyor; and a production amount calculator that obtains the electric power supplied to the electric motor and calculates, from the obtained electric power and the correlation between the electric power and the transportation amount, the transportation amount corresponding to the obtained electric power as a production amount in the production apparatus.

[0140] According to the above configuration, by obtaining the electric power supplied to the electric motor that drives the transport conveyor, the transportation amount by the transport conveyor can be calculated as the production amount of the product transported by the transport conveyor, by using the correlation between the electric power and the transportation amount, the correlation being stored in the storage. Therefore, the production amount of the product can be readily calculated at low cost without having to, for example, equip the transport conveyor with a belt scale capable of weighing the transportation amount or additionally install means for detecting the transportation amount.

[0141] [Item 16] In the production amount detector of item 15, the production apparatus may include a classifier that performs classification to classify the produced product into at least afirst-type product and a second-type product in accordance with a predetermined reference. The transport conveyor may include a first conveyor that transports the first-type product and a second conveyor that transports the second-type product. The production amount calculator may obtain first electric power supplied to an electric motor that drives the first conveyor and second electric power supplied to an electric motor that drives the second conveyor.

[0142] According to the above configuration, the production amounts of multiple types of products, respectively, obtained from the production apparatus can be readily calculated, which makes it possible to readily check the production balance between the multiple types of products.

[0143] [Item 17] In the production amount detector of item 16, the production apparatus may include a gyratory crusher that crushes objects to be crushed, and the classifier may perform classification to classify the crushed objects in accordance with a predetermined grain size range.

[0144] [Item 18] A production amount detection system according to yet another aspect of the present disclosure is a production amount detection system in a production apparatus that produces a predetermined product by performing a predetermined process on a raw material fed into the production apparatus, the production apparatus including a transport conveyor that transports the produced product, the production amount detection system including: an electric power measurer that measures electric power supplied to an electric motor that drives the transport conveyor; and the production amount detector according to any one of items 15 to 17.

[0145] [Item 19] A production amount detection method according to yet another aspect of the present disclosure is a method of detecting a production amount in a production apparatus that produces a predetermined product by performing a predetermined process on a raw material fed into the production apparatus, the production apparatus including a transport conveyor that transports the produced product, the production amount detection method including: detecting electric power supplied to an electric motor that drives the transport conveyor; obtaining a correlation between the electric power and a transportation amount per unit time by the transport conveyor; and calculating, from the detected electric power and the correlation between the electric power and the transportation amount, the transportation amount corresponding to the detected electric power as the production amount.

Claims (14)

1. [Claim1] A controller of a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the controller including processing circuitry, wherein the processing circuitry: obtains a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculates a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generates the load index target value based on the obtained load index and a correlation between the load index and the grain size ratio; and generates a control command value from the load index and the load index target value, and the controller controls at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.
2. [Claim 2] The controller according to claim 1, wherein the crushing system includes a classifier that performs classification to classify, in terms of grain size, the objects that have been crushed by the gyratory crusher, and the processing circuitry: obtains a grain size index that directly or indirectly indicates the production amount of the product in the predetermined grain size range, the product being sorted out by the classification by the classifier; and calculates the grain size ratio by using the grain size index.
3. [Claim 3] The controller according to claim 2, wherein the crushing system includes a transport conveyor located downstream of the classifier, wherein the transport conveyer transports the product that is in the predetermined grain size range and that has been sorted out, and the processing circuitry calculates the grain size ratio by using, as the production amount of the product in the predetermined grain size range, a transportation amount per unit time of the product transported by the transport conveyor.
4. [Claim 4] The controller according to claim 3, wherein the processing circuitry obtains, as the grain size index, electric power supplied to an electric motor that drives the transport conveyor.
5. [Claim 5] The controller according to claim 3, wherein the processing circuitry: obtains a feeding amount per unit time of the objects to be crushed that are fed to the gyratory crusher; and calculates, as the grain size ratio, a proportion of the transportation amount by the transport conveyor to the feeding amount.
6. [Claim 6] The controller according to claim 1, wherein the processing circuitry calculates, from the correlation and the obtained load index, the grain size ratio corresponding to the load index.
7. [Claim 7] The controller according to any one of claims 1 to 6, wherein the processing circuitry: sets a control gain from the obtained load index and the correlation, and generates the load index target value based on the control gain and a grain size ratio deviation that is obtained by subtracting the grain size ratio from a predetermined grain size ratio target value.
8. [Claim 8] The controller according to claim 7, including a storage that stores the correlation, wherein the processing circuitry calculates the control gain from the obtained load index and the correlation that is stored in advance in the storage.
9. [Claim 9] The controller according to claim 7, including a storage that stores the obtained load index and a history of the calculated grain size ratio, wherein the processing circuitry calculates the correlation by calculating, from two or more past combinations of the load index and the grain size ratio, a change rate of the grain size ratio in relation to the load index, and calculates the control gain from the obtained load index and the calculated correlation.
10. [Claim 10] The controller according to claim 7, wherein the processing circuitry includes: a control gain multiplier that multiplies the grain size ratio deviation by the control gain; and a limiter that limits an output from the control gain multiplier to fall within a predetermined limited range, and the limited range is set in accordance with the obtained load index.
11. [Claim 11] A crushing system including: a gyratory crusher; a feeder that feeds objects to be crushed to the gyratory crusher; and the controller according to any one of claims 1 to 6.
12. [Claim 12] The crushing system according to claim 11, wherein the gyratory crusher includes: a mantle fixed to a main shaft that turns eccentrically; and a concave including therein a crushing chamber in which the objects to be crushed are caught and crushed between the mantle and the concave, a set between the mantle and the concave is mechanically maintained, and the controller controls a feeding amount of the objects to be crushed that are fed to the gyratory crusher.
13. [Claim 13] The crushing system according to claim 11, wherein the gyratory crusher includes: a mantle fixed to a main shaft that turns eccentrically; a concave including therein a crushing chamber in which the objects to be crushed are caught and crushed between the mantle and the concave; and a hydraulic cylinder that applies, to the mantle or the concave, hydraulic force against crushing force, such that a set between the mantle and the concave is maintained, and the controller controls at least one of a feeding amount of the objects to be crushed that are fed to the gyratory crusher or a size of the set.
14. [Claim 14] A method of controlling a crushing system, the crushing system including a gyratory crusher and a feeder that feeds objects to be crushed to the gyratory crusher, the method including: detecting a load index that directly or indirectly indicates a crushing load on the gyratory crusher; calculating a grain size ratio that indicates a production amount of a product as a ratio of the production amount of the product to a predetermined reference production amount, the product being obtained from the objects that have been crushed by the gyratory crusher and being in a predetermined grain size range; generating the load index target value based on the detected load index and a correlation between the load index and the grain size ratio; and generating, from the load index and the load index target value, a control command value to control at least one of the gyratory crusher or the feeder, such that the load index is within a reference range that is based on the load index target value.