Crusher

Abstract

To facilitate both work efficiency and safety by preventing sudden stoppage due to overload in a crusher.SOLUTION: The crusher includes first and second inverter devices and a biaxial control device. When a second torque moving average value is less than a second torque limit value and an overload warning signal does not indicate execution of overload protection control, a second drive motor is driven in a rotation direction corresponding to a first torque moving average value and at a rotational speed slower than that of a first drive motor corresponding to the first torque moving average value. When the second torque moving average value is equal to or greater than the second torque limit value, the second drive motor is driven in a reverse direction. When the second torque moving average value is less than the second torque limit value and the overload warning signal indicates execution of the overload protection control, the second drive motor is driven in the reverse direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This specification discloses technologies related to crushers.

Background Art

[0002] Twin-shaft crushers are known as crushers. A twin-shaft crusher includes two rotating shafts that are arranged parallel to each other and have crushing blades provided on their outer peripheries respectively, and crushes the waste fed between the crushing blades by rotating the two rotating shafts.

[0003] Patent Documents 1 and 2 disclose twin-shaft crushers that drive the rotating shafts using a three-phase induction drive motor with inverter control. The twin-shaft crusher of Patent Document 1 detects the output torque of the drive motor by a sensor and performs the crushing process while feedback-controlling the drive motor using the sensor detection value. The twin-shaft crusher of Patent Document 2 detects the rotational speed of the drive motor by a sensor and performs the crushing process while feedback-controlling the drive motor using the sensor detection value.

[0004] Also, generally, sensorless vector control is known as one of the methods for controlling a three-phase induction drive motor (see, for example, Patent Document 3). Sensorless vector control estimates the output torque and rotational speed of the drive motor based on the current value and voltage value supplied to the drive motor, and feedback-controls the drive motor using the estimated values. Thereby, sensorless vector control can control the drive motor without the need for feedback by the sensor detection values of the output torque and rotational speed of the drive motor.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

[0006] Special In twin-shaft shredders, it is crucial to prevent overloading of the rotating shaft before it causes a sudden stop (lockup). A sudden stop of the rotating shaft can cause damage to various parts of the shredder, including the shredding blades, as well as a decrease in work efficiency due to the cessation of the shredding process. [Means for solving the problem]

[0007] The technologies disclosed herein can be implemented in the following forms: One embodiment disclosed herein is a crusher. This crusher comprises a first rotating shaft having a first crushing blade on its outer circumference, a second rotating shaft arranged parallel to the first rotating shaft and having a second crushing blade on its outer circumference, and a two-axis control device that controls the operation of the first rotating shaft and the second rotating shaft. This crusher crushes waste fed between the first crushing blade and the second crushing blade by rotating the first rotating shaft and the second rotating shaft in the forward direction. The two-axis control device, when the first average torque displacement value output to the first rotating shaft is less than a set value and the first rotating shaft is driven in the forward direction at a constant rotational speed while the second rotating shaft is driven in the forward direction, controls the first average torque displacement value to drive the first rotating shaft in the forward direction at a constant rotational speed while the second rotating shaft is driven in the reverse direction when the first average torque displacement value changes from less than the set value to or greater than the set value, and then controls the first rotating shaft to drive the first rotating shaft in the forward direction at a constant rotational speed while the second rotating shaft is driven in the forward direction again when the first average torque displacement value changes from greater than or equal to the set value to less than the set value.

[0008] One embodiment disclosed herein is a crusher comprising: a first rotating shaft having a first crushing blade on its outer circumference; and a second rotating shaft arranged parallel to the first rotating shaft and having a second crushing blade on its outer circumference, wherein the crusher crushes waste fed between the first and second crushing blades by rotating the first and second rotating shafts in the forward direction. The crusher comprises: a two-axis control device that controls the operation of the first and second rotating shafts; a first drive motor that rotationally drives the first rotating shaft; a first inverter device that controls the rotation of the first drive motor by first sensorless vector control based on instructions from the two-axis control device; a second drive motor that rotationally drives the second rotating shaft; and a second inverter device that controls the rotation of the second drive motor by second sensorless vector control based on instructions from the two-axis control device. The first inverter device outputs a first estimated output torque value, which is estimated as the output torque of the first drive motor in the first sensorless vector control, to the two-axis control device; determines whether the first drive motor is in an overload state; if it determines that the first drive motor is in an overload state, it executes overload protection control to protect the first drive motor from overload; and if it executes the overload protection control, it outputs an overload alarm signal to the two-axis control device indicating the execution of the overload protection control. The second inverter device outputs a second estimated output torque value, which is estimated as the output torque of the second drive motor in the second sensorless vector control, to the two-axis control device.The two-axis control device calculates a first torque moving average value, which is the moving average value of the first estimated output torque value input from the first inverter device; calculates a second torque moving average value, which is the moving average value of the second estimated output torque value input from the second inverter device; if the first torque moving average value is less than the first torque limit value, it instructs the first inverter device to drive the first drive motor in the forward direction at a first rotational speed; if the first torque moving average value is equal to or greater than the first torque limit value, it instructs the first inverter device to drive the first drive motor in the reverse direction; if the second torque moving average value is less than the second torque limit value Furthermore, if the overload alarm signal does not indicate the execution of the overload protection control, the second inverter device is instructed to drive the second drive motor in the rotation direction corresponding to the first torque movement average value and at a rotation speed slower than the first rotation speed corresponding to the first torque movement average value; if the second torque movement average value is greater than or equal to the second torque limit value, the second inverter device is instructed to drive the second drive motor in the reverse direction; and if the second torque movement average value is less than the second torque limit value and the overload alarm signal indicates the execution of the overload protection control, the second inverter device is instructed to drive the second drive motor in the reverse direction. In this type of crusher, overload of the first rotating shaft, which cannot be completely avoided by controlling the second drive motor based on the rotation direction and rotation speed corresponding to the first torque transfer average value, can be avoided by controlling the second drive motor based on an overload warning signal from the first inverter device. As a result, sudden stops due to overload of the first rotating shaft can be prevented, making it easy to achieve both work efficiency and a safety factor.

[0009] The technology disclosed herein can be implemented in various forms different from that of a crusher. For example, the technology disclosed herein can be implemented in the form of a control device and control method for a crusher. [Brief explanation of the drawing]

[0010] [Figure 1]This is an explanatory diagram showing the configuration of a crusher. [Figure 2] This is an explanatory diagram showing the internal structure of the crusher's processing container. [Figure 3] This flowchart shows the two-axis control process performed by the processor of a two-axis control device. [Figure 4] This flowchart shows the high-speed axis control process performed by the processor of a two-axis control system. [Figure 5] This flowchart shows the low-speed axis control process performed by the processor of a two-axis control system. [Modes for carrying out the invention]

[0011] Figure 1 is an explanatory diagram showing the configuration of the crusher 10. The crusher 10 is a twin-shaft crusher for crushing waste. The crusher 10 comprises a processing container 110, a rotating shaft 210, a rotating shaft 220, a twin-shaft control device 300, an inverter device 410, an inverter device 420, a drive motor 510, a drive motor 520, a reduction gear 610, and a reduction gear 620. The explanatory diagram in Figure 1 includes a plan view of the processing container 110 as seen from above.

[0012] Figure 2 is an explanatory diagram showing the internal configuration of the processing container 110 of the crusher 10. The explanatory diagram in Figure 2 includes a cross-sectional view obtained by cutting the processing container 110 along the cross-section F2-F2 in Figure 1. Cross-section F2-F2 is a plane perpendicular to the two rotation axes 210 and 220 and perpendicular to the horizontal plane.

[0013] The rotating shaft 210 of the crusher 10 is rotatably mounted inside the processing container 110. The rotating shaft 210 is an axis that extends parallel to the horizontal plane. Multiple crushing blades 212 and spacers 214 are alternately provided on the outer circumference of the rotating shaft 210.

[0014] The rotating shaft 220 of the crusher 10 is rotatably mounted inside the processing container 110. The rotating shaft 220 is an axis that extends parallel to the horizontal plane. The rotating shaft 220 is positioned parallel to the rotating shaft 210. The rotating shaft 220 is positioned on the same horizontal plane as the rotating shaft 210. Multiple crushing blades 222 and spacers 224 are alternately provided on the outer circumference of the rotating shaft 220. The crushing blades 222 of the rotating shaft 220 are positioned opposite the spacers 214 of the rotating shaft 210. The spacers 214 of the rotating shaft 220 are positioned opposite the crushing blades 212 of the rotating shaft 210.

[0015] The processing container 110 of the crusher 10 is a container configured to perform the crushing of waste 810 on its inside. Two rotating shafts 210 and 220 are provided inside the processing container 110. The processing container 110 has an inlet 112 and an outlet 118. The inlet 112 of the processing container 110 receives the waste 810 that is fed into the processing container 110 from above and into the processing container 110. The outlet 118 of the processing container 110 discharges the crushed waste 810, which is the crushed waste 810, to the bottom of the processing container 110.

[0016] The crusher 10 crushes the waste 810 fed from above between the crushing blades 212 and 222 by rotating the rotating shafts 210 and 220 in the forward direction FR, respectively. The crusher 10 is configured so that the rotating shaft 210 can also rotate in the reverse direction RR, which is the opposite direction to the forward direction FR. The crusher 10 is configured so that the rotating shaft 220 can also rotate in the reverse direction RR, which is the opposite direction to the forward direction FR.

[0017] The inverter device 410 of the crusher 10 controls the drive motor 510 based on instructions from the two-axis control device 300. The inverter device 410 includes a processor 412, a memory 414, a converter circuit 415, an inverter circuit 416, a voltage sensor 417, a current sensor 418, and various interfaces. The processor 412 realizes various processes for controlling the drive motor 510 by executing program instructions stored in the memory 414. The converter circuit 415 rectifies the AC power supplied from the commercial power supply into DC power. The inverter circuit 416 converts, by pulse width modulation (PWM), the DC power rectified by the converter circuit 415 into three-phase AC power supplied to the drive motor 510 based on instructions from the processor 412. The voltage sensor 417 detects the DC voltage CV1 output from the converter circuit 415 and the output voltage MV1 output to the drive motor 510. The current sensor 418 detects the output current MI1 output to the drive motor 510.

[0018] The inverter device 410 controls the drive motor 510 by sensorless vector control that refers to the output current MI1 and the output voltage MV1 output from the inverter device 410 to the drive motor 510. The inverter device 410 outputs an estimated output torque value TE1 estimated as the output torque of the drive motor 510 in sensorless vector control to the two-axis control device 300. In the present embodiment, the inverter device 410 smoothes the value calculated as the output torque of the drive motor 510 in sensorless vector control with a low-pass filter to remove noise, and outputs the value to the two-axis control device 300 as the estimated output torque value TE1.

[0019] When the inverter device 410 determines that the drive motor 510 is in an overload state, it executes overload protection control to protect the drive motor 510 from overload. When the estimated output torque value TE1 exceeds the torque limit value (for example, 210% of the rated torque of the drive motor 510), the inverter device 410 determines that the drive motor 510 is in an overload state. In this case, the inverter device 410 controls the drive motor 510 so that torque exceeding the torque limit value does not occur as overload protection control. Also, when the regenerative energy of the drive motor 510 becomes excessive during deceleration of the drive motor 510 and the DC voltage CV1 output from the converter circuit 415 exceeds the voltage limit value (for example, 190% (380V) of the power supply voltage (200V)), the inverter device 410 determines that the drive motor 510 is in an overload state. In this case, the inverter device 410 stops the decrease in the frequency of the output power to the drive motor 510 as overload protection control.

[0020] While executing overload protection control for the drive motor 510, the inverter device 410 outputs an overload alarm signal A1 indicating the execution of the overload protection control to the two-axis control device 300. In the present embodiment, the overload alarm signal A1 indicates a value "0" when the overload protection control is not being executed, and indicates a value "1" when the overload protection control is being executed.

[0021] The inverter device 420 of the crusher 10 controls the drive motor 520 based on instructions from the twin-axis control device 300. The inverter device 420 includes a processor 422, a memory 424, a converter circuit 425, an inverter circuit 426, a voltage sensor 427, a current sensor 428, and various interfaces. The processor 422 performs various processes to control the drive motor 520 by executing program instructions stored in the memory 424. The converter circuit 425 rectifies the AC power supplied from the commercial power supply into DC power. Based on instructions from the processor 422, the inverter circuit 426 converts the DC power rectified by the converter circuit 425 into three-phase AC power supplied to the drive motor 520 using pulse width modulation (PWM). The voltage sensor 427 detects the DC voltage CV2 output from the converter circuit 425 and the output voltage MV2 output to the drive motor 520. The current sensor 428 detects the output current MI2 that is output to the drive motor 520. In this embodiment, the inverter device 420 is an inverter device with the same specifications as the inverter device 410.

[0022] The inverter device 420 controls the drive motor 520 by sensorless vector control, which involves referencing the output current MI2 and output voltage MV2 output from the inverter device 420 to the drive motor 520. The inverter device 420 outputs an estimated output torque value TE2, which is estimated as the output torque of the drive motor 520 in sensorless vector control, to the two-axis control device 300. In this embodiment, the inverter device 420 smooths the value calculated as the output torque of the drive motor 520 in sensorless vector control using a low-pass filter to remove noise, and outputs this value as the estimated output torque value TE2 to the two-axis control device 300.

[0023] The inverter device 420 performs overload protection control to protect the drive motor 520 from overload if it determines that the drive motor 520 is in an overload state. The inverter device 420 determines that the drive motor 520 is in an overload state if the estimated output torque value TE2 exceeds the torque limit value (for example, 210% of the rated torque of the drive motor 520). In this case, the inverter device 420 controls the drive motor 520 as an overload protection control to prevent the generation of torque exceeding the torque limit value. Also, if the regenerative energy of the drive motor 520 becomes excessive during deceleration and the DC voltage CV2 output from the converter circuit 425 exceeds the voltage limit value (for example, 190% (380V) of the power supply voltage (200V)), the inverter device 420 determines that the drive motor 520 is in an overload state. In this case, the inverter device 420 stops the frequency reduction of the output power to the drive motor 520 as an overload protection control.

[0024] The inverter device 420 outputs an overload alarm signal A2 to the two-axis control device 300 to indicate the execution of overload protection control while executing overload protection control on the drive motor 520. In this embodiment, the overload alarm signal A2 shows a value of "0" when overload protection control is not being executed, and shows a value of "1" when overload protection control is being executed.

[0025] The drive motor 510 of the crusher 10 rotates the rotating shaft 210. The drive motor 510 is a three-phase induction drive motor. The drive motor 510 outputs rotational power to the output shaft 512 based on three-phase alternating current supplied from the inverter device 410. The rotational power of the drive motor 510 is transmitted to the rotating shaft 210 via a reduction gear 610 connected to the output shaft 512.

[0026] The drive motor 520 of the crusher 10 rotates the rotating shaft 220. The drive motor 520 is a three-phase induction drive motor. In this embodiment, the drive motor 520 is a three-phase induction drive motor with the same specifications as the drive motor 510. The drive motor 520 outputs rotational power to the output shaft 522 based on the three-phase alternating current supplied from the inverter device 420. The rotational power of the drive motor 520 is transmitted to the rotating shaft 220 via a reduction gear 620 connected to the output shaft 522.

[0027] The reduction gear 610 of the crusher 10 reduces the rotational power output from the drive motor 510 and transmits it to the rotating shaft 210. The reduction gear 610 is a mechanical device equipped with multiple gears. In this embodiment, when the inverter device 410 drives the drive motor 510 with a 60Hz (Hertz) three-phase AC, the rotational power of the output shaft 512 is reduced via the reduction gear 610, causing the rotating shaft 210 to rotate at approximately 10 rpm (revolutions per minute). The rotational speed of the drive motor 510 and the rotating shaft 210 increases in proportion to the increase in the frequency of the three-phase AC supplied from the inverter device 410, and decreases in proportion to the decrease in that frequency.

[0028] The reduction gear 620 of the crusher 10 reduces the rotational power output from the drive motor 520 and transmits it to the rotating shaft 220. The reduction gear 620 is a mechanical device equipped with multiple gears. In this embodiment, the reduction gear 620 is a mechanical device with the same specifications as the reduction gear 610.

[0029] The twin-shaft control device 300 of the crusher 10 controls the operation of the rotating shafts 210 and 220. The twin-shaft control device 300 is a computer equipped with a processor 310, memory 320, and various interfaces. The twin-shaft control device 300 controls one of the rotating shafts 210 and 220 as a high-speed drive shaft SF and the other as a low-speed drive shaft SL. The twin-shaft control device 300 switches between the high-speed drive shaft SF and the low-speed drive shaft SL at predetermined operating times (for example, 60 minutes) with the aim of equalizing the wear of each part of the crusher 10.

[0030] When the rotating shaft 210 is set as the high-speed drive shaft SF (first rotating shaft) and the rotating shaft 220 is set as the low-speed drive shaft SL (second rotating shaft), the inverter device 410 is set as the high-speed side inverter device IF (first inverter device), and the drive motor 510 is set as the high-speed side drive motor MF (first drive motor). In this case, the inverter device 420 is set as the low-speed side inverter device IL (second inverter device), and the drive motor 520 is set as the low-speed side drive motor ML (second drive motor). The inverter device 410, which is the high-speed side inverter device IF, outputs the estimated output torque value TE1 as the estimated output torque value TF (first estimated output torque value) to the dual-axis control device 300, and also outputs the overload alarm signal A1 as the high-speed side alarm signal AF from the high-speed side inverter device IF to the dual-axis control device 300. The inverter device 420, which is the low-speed inverter device IL, outputs the estimated output torque value TE2 as the estimated output torque value TL (second estimated output torque value) to the two-axis control device 300.

[0031] When the rotating shaft 220 is set as the high-speed drive shaft SF (first rotating shaft) and the rotating shaft 210 is set as the low-speed drive shaft SL (second rotating shaft), the inverter device 420 is set as the high-speed side inverter device IF (first inverter device), and the drive motor 520 is set as the high-speed side drive motor MF (first drive motor). In this case, the inverter device 410 is set as the low-speed side inverter device IL (second inverter device), and the drive motor 510 is set as the low-speed side drive motor ML (second drive motor). The inverter device 420, which is the high-speed side inverter device IF, outputs the estimated output torque value TE2 as the estimated output torque value TF (first estimated output torque value) to the dual-axis control device 300, and also outputs the overload alarm signal A2 as the high-speed side alarm signal AF from the high-speed side inverter device IF to the dual-axis control device 300. The inverter device 410, which is the low-speed inverter device IL, outputs the estimated output torque value TE1 as the estimated output torque value TL (second estimated output torque value) to the two-axis control device 300.

[0032] The twin-axis control device 300 calculates the moving average torque value TFA, which is the moving average of the estimated output torque value TF input from the high-speed inverter device IF. In this embodiment, the twin-axis control device 300 extracts the four most recent estimated output torque values ​​TF and calculates the moving average torque value TFA from these four estimated output torque values ​​TF. The number of estimated output torque values ​​TF used to calculate the moving average torque value TFA may be other than four and can be set appropriately according to the configuration of the crusher 10.

[0033] The twin-axis control device 300 calculates the moving average torque value TLA, which is the moving average of the estimated output torque value TL input from the low-speed inverter device IL. In this embodiment, the twin-axis control device 300 extracts the four most recent estimated output torque values ​​TL and calculates the moving average torque value TLA from these four estimated output torque values ​​TL. The number of estimated output torque values ​​TL used to calculate the moving average torque value TLA may be other than four and can be set appropriately according to the configuration of the crusher 10.

[0034] If the average torque shift value TFA is greater than or equal to the torque limit value TFmax, the two-axis control device 300 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in the reverse direction RR (70Hz drive in this embodiment). On the other hand, if the average torque shift value TFA is less than the torque limit value TFmax, the two-axis control device 300 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in the forward direction FR at a first rotational speed (60Hz drive in this embodiment).

[0035] Furthermore, if the average torque movement value TLA is greater than or equal to the torque limit value TLmax, the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the reverse direction RR (70Hz drive in this embodiment).

[0036] On the other hand, if the average torque shift value TLA is less than the torque limit value TLmax, and the high-speed side alarm signal AF does not indicate the execution of overload protection control for the high-speed side drive motor MF, the two-axis control device 300 instructs the low-speed side inverter device IL to drive the low-speed side drive motor ML in the rotation direction corresponding to the average torque shift value TFA, and at a rotation speed slower than the first rotation speed corresponding to the average torque shift value TFA (in this embodiment, driving in the forward direction FR at 6Hz, 4.5Hz, or 3Hz, and driving in the reverse direction RR at 30Hz).

[0037] Furthermore, if the torque moving average value TLA is less than the torque limit value TLmax, and the high-speed side alarm signal AF indicates the execution of overload protection control for the high-speed side drive motor MF, the dual-axis control device 300 instructs the low-speed side inverter device IL to drive the low-speed side drive motor ML in the reverse direction RR (driven at 6Hz in this embodiment). Since the responsiveness of detecting overload of the high-speed drive shaft SF based on the high-speed side alarm signal AF is higher than the torque moving average value TFA, which is the moving average value of the estimated output torque value TF smoothed by a low-pass filter, overload of the high-speed drive shaft SF that cannot be avoided by control based on the torque moving average value TFA can be prevented by control based on the high-speed side alarm signal AF.

[0038] Figure 3 is a flowchart showing the two-axis control process executed by the processor 310 of the two-axis control device 300. The two-axis control process in Figure 3 is for controlling the movement of the rotary axis 210 and the rotary axis 220. The processor 310 of the two-axis control device 300 repeatedly executes the two-axis control process in Figure 3 at predetermined timings by executing program instructions stored in the memory 320.

[0039] After starting the two-axis control process shown in Figure 3, the processor 310 of the two-axis control device 300 determines whether it is the axis setting timing to switch between the high-speed drive axis SF and the low-speed drive axis SL between the rotating axis 210 and the rotating axis 220 (step S110). In this embodiment, the processor 310 determines that it is the axis setting timing if 60 minutes have elapsed since the previous axis setting timing and the crushing process has been performed.

[0040] If it is the axis setting timing (step S110: "YES"), the processor 310 of the two-axis control device 300 switches the settings between the rotary axis 210 and the rotary axis 220 as high-speed drive axis SF and low-speed drive axis SL (step S120). For example, if the axis setting timing occurs when the rotary axis 210 is set as high-speed drive axis SF and the rotary axis 220 is set as low-speed drive axis SL, the processor 310 sets the rotary axis 220 as high-speed drive axis SF and the rotary axis 210 as low-speed drive axis SL. Conversely, if the axis setting timing occurs when the rotary axis 220 is set as high-speed drive axis SF and the rotary axis 210 is set as low-speed drive axis SL, the processor 310 sets the rotary axis 210 as high-speed drive axis SF and the rotary axis 220 as low-speed drive axis SL.

[0041] If it is not the axis setting timing (step S110: "NO"), or after switching between the high-speed drive axis SF and the low-speed drive axis SL (step S120), the processor 310 of the dual-axis control device 300 reads the estimated output torque value TF and the high-speed alarm signal AF of the high-speed drive motor MF input from the high-speed inverter device IF into the memory 320, and also reads the estimated output torque value TL of the low-speed drive motor ML input from the low-speed inverter device IL into the memory 320 (step S130).

[0042] After reading various signals from the high-speed inverter device IF and the low-speed inverter device IL (step S130), the processor 310 of the two-axis control device 300 calculates the moving average torque TFA, which is the moving average of the estimated output torque value TF input from the high-speed inverter device IF (step S140). The processor 310 reads a predetermined number (four in this embodiment) of the most recent estimated output torque values ​​TF from the memory 320 and calculates the moving average torque TFA from these estimated output torque values ​​TF. The processor 310 stores the moving average torque TFA in the memory 320.

[0043] After calculating the torque moving average value TFA (step S140), the processor 310 of the two-axis control device 300 calculates the torque moving average value TLA, which is the moving average value of the estimated output torque value TL input from the low-speed inverter device IL (step S150). The processor 310 reads a predetermined number (four in this embodiment) of the most recent estimated output torque values ​​TL from the memory 320 and calculates the torque moving average value TLA from these estimated output torque values ​​TL. The processor 310 stores the torque moving average value TLA in the memory 320.

[0044] After calculating the average torque shift value TLA (step S150), the processor 310 of the two-axis control device 300 executes high-speed axis control processing (step S200) and low-speed axis control processing (step S300). High-speed axis control processing (step S200) is the process of controlling the rotation of the high-speed drive axis SF. Low-speed axis control processing (step S300) is the process of controlling the rotation of the low-speed drive axis SL. After completing high-speed axis control processing (step S200) and low-speed axis control processing (step S300), the processor 310 terminates the two-axis control processing shown in Figure 3.

[0045] Figure 4 is a flowchart of the high-speed axis control process (step S200) executed by the processor 310 of the two-axis control device 300. After starting the high-speed axis control process (step S200), the processor 310 reads the average torque movement TFA of the high-speed drive motor MF from the memory 320 (step S210).

[0046] After reading the average torque shift value TFA of the high-speed drive motor MF (step S210), the processor 310 of the two-axis control device 300 determines whether the average torque shift value TFA read from the memory 320 is greater than or equal to the torque limit value TFmax (step S220). In this embodiment, the torque limit value TFmax is set to 200% of the rated torque of the high-speed drive motor MF. In other embodiments, the torque limit value TFmax may be less than 200% of the rated torque of the high-speed drive motor MF, or it may be greater than 200% of the rated torque of the high-speed drive motor MF.

[0047] If the average torque shift value TFA of the high-speed drive motor MF is less than the torque limit value TFmax (step S220: "NO"), the processor 310 of the two-axis control device 300 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in forward rotation (step S230). The forward rotation of the high-speed drive motor MF (step S230) is a control that rotates the high-speed drive shaft SF in the forward rotation direction FR at a speed sufficient to crush the waste 810. In this embodiment, during the forward rotation of the high-speed drive motor MF (step S230), the processor 310 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in the forward rotation direction FR with a three-phase AC current at a frequency of 60 Hz (first rotation speed). After instructing the high-speed inverter device IF to perform the forward rotation of the high-speed drive motor MF (step S230), the processor 310 terminates the high-speed shaft control process (step S200) shown in Figure 4.

[0048] If the average torque transfer value TFA of the high-speed drive motor MF is greater than or equal to the torque limit value TFmax (step S220: "YES"), the processor 310 of the two-axis control device 300 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in reverse operation (step S240). The reverse operation of the high-speed drive motor MF (step S240) is a control that rotates the high-speed drive shaft SF in the reverse direction RR to prevent damage to the crusher 10 due to excessive load on the high-speed drive shaft SF. In this embodiment, during the reverse operation of the high-speed drive motor MF (step S240), the processor 310 instructs the high-speed inverter device IF to drive the high-speed drive motor MF in the reverse direction RR with a three-phase AC current at a frequency of 70Hz. In this embodiment, the frequency (70Hz) used to drive the high-speed drive motor MF in reverse operation (step S240) is higher than the frequency (60Hz) used to drive the high-speed drive motor MF in forward operation (step S230). In other embodiments, the frequency of the reverse rotation operation (step S240) may be the same as the frequency of the forward rotation operation (step S230), or it may be lower than the frequency of the forward rotation operation (step S230). After instructing the high-speed inverter device IF to reverse the high-speed drive motor MF (step S240), the processor 310 terminates the high-speed axis control process (step S200) shown in Figure 4.

[0049] Figure 5 is a flowchart of the low-speed axis control process (step S300) executed by the processor 310 of the two-axis control device 300. After starting the low-speed axis control process (step S300), the processor 310 reads the average torque movement value TFA of the high-speed drive motor MF, the high-speed alarm signal AF, and the average torque movement value TLA of the low-speed drive motor ML from the memory 320 (step S310).

[0050] After reading the average torque shift value TFA, the high-speed alarm signal AF, and the average torque shift value TLA (step S310), the processor 310 of the two-axis control device 300 determines whether the average torque shift value TLA of the low-speed drive motor ML read from the memory 320 is greater than or equal to the torque limit value TLmax (step S320). In this embodiment, the torque limit value TLmax is set to 200% of the rated torque of the low-speed drive motor ML. In other embodiments, the torque limit value TLmax may be less than 200% of the rated torque of the low-speed drive motor ML, or it may be greater than 200% of the rated torque of the low-speed drive motor ML.

[0051] If the average torque shift value TLA of the low-speed drive motor ML is greater than or equal to the torque limit value TLmax (step S320: "YES"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in reverse (step S325). The reverse operation of the low-speed drive motor ML (step S325) is a control that rotates the low-speed drive shaft SL in the reverse direction RR to prevent damage to the crusher 10 due to excessive load on the low-speed drive shaft SL. In this embodiment, in the reverse operation of the low-speed drive motor ML (step S325), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the reverse direction RR with a three-phase AC current at a frequency of 70 Hz (second rotational speed). In this embodiment, the frequency (70Hz) used to drive the low-speed drive motor ML in reverse rotation (step S325) is higher than the frequency (60Hz) used to drive the high-speed drive motor MF in forward rotation (step S230 in Figure 4). In other embodiments, the frequency of the reverse rotation (step S325) may be the same as the frequency of the forward rotation of the high-speed drive motor MF (step S230 in Figure 4), or it may be lower than the frequency of the forward rotation of the high-speed drive motor MF (step S230 in Figure 4). After instructing the low-speed inverter device IL to reverse the low-speed drive motor ML (step S325), the processor 310 terminates the low-speed axis control process (step S300) shown in Figure 5.

[0052] If the average torque transfer value TLA of the low-speed drive motor ML is less than the torque limit value TLmax (step S320: "NO"), the processor 310 of the two-axis control device 300 determines whether the high-speed alarm signal AF is value "1", that is, whether the high-speed inverter device IF is performing overload protection control (step S330).

[0053] If the high-speed alarm signal AF is value "1", that is, if the high-speed inverter device IF is performing overload protection control (step S330: "YES"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in reverse (step S335). The reverse operation of the low-speed drive motor ML (step S335) is a control that rotates the low-speed drive shaft SL in the reverse direction RR to alleviate the overload of the high-speed drive shaft SF, which is under overload protection control. In this embodiment, in the reverse operation of the low-speed drive motor ML (step S335), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the reverse direction RR with a three-phase AC current at a frequency of 6 Hz (third rotational speed). In this embodiment, the frequency (6Hz) of the reverse operation based on the high-speed alarm signal AF (step S335) is lower than the frequency (70Hz) of the reverse operation based on the torque shift average value TLA (step S325). After instructing the low-speed inverter device IL to reverse the low-speed drive motor ML (step S335), the processor 310 terminates the low-speed shaft control process (step S300) shown in Figure 5.

[0054] If the high-speed alarm signal AF is value "0", that is, if the high-speed inverter device IF is not performing overload protection control (step S330: "NO"), the processor 310 of the two-axis control device 300 determines whether the average torque shift value TFA of the high-speed drive motor MF is 150% or more but less than 200% of the rated torque (step S340).

[0055] If the average torque shift value TFA of the high-speed drive motor MF is 150% or more but less than 200% of the rated torque (step S340: "YES"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in reverse (step S345). The reverse operation of the low-speed drive motor ML (step S345) is a control that rotates the low-speed drive shaft SL in the reverse direction RR to reduce the overload of the high-speed drive shaft SF. In this embodiment, in the reverse operation of the low-speed drive motor ML (step S345), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the reverse direction RR with a three-phase AC current at a frequency of 30 Hz. In this embodiment, the frequency (30 Hz) of the reverse operation based on the average torque shift value TFA (step S345) is higher than the frequency (70 Hz) of the reverse operation based on the average torque shift value TLA (step S325). The speed is low. After instructing the low-speed inverter device IL to reverse the operation of the low-speed drive motor ML (step S345), the processor 310 terminates the low-speed axis control process (step S300) shown in Figure 5.

[0056] If the average torque transfer value TFA of the high-speed drive motor MF is less than 150% of the rated torque (step S340: "NO"), the processor 310 of the two-axis control device 300 determines whether the average torque transfer value TFA of the high-speed drive motor MF is 80% or more but less than 150% of the rated torque (step S350).

[0057] If the average torque shift value TFA of the high-speed drive motor MF is 80% or more but less than 150% of the rated torque (step S350: "YES"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in forward rotation (step S355). The forward rotation of the low-speed drive motor ML (step S355) is a control that rotates the low-speed drive shaft SL in the forward rotation direction FR when the load on the high-speed drive shaft SF is relatively high, thereby continuing the crushing process. In this embodiment, in the forward rotation of the low-speed drive motor ML (step S355), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the forward rotation direction FR with a three-phase AC current at a frequency of 3 Hz. In this embodiment, the frequency (3Hz) used to control the low-speed drive motor ML during forward rotation (step S355) is lower than the frequency (60Hz) used to drive the high-speed drive motor MF during forward rotation (step S230 in Figure 4). After instructing the low-speed inverter device IL to perform forward rotation of the low-speed drive motor ML (step S355), the processor 310 terminates the low-speed axis control process (step S300) shown in Figure 5.

[0058] If the average torque transfer value TFA of the high-speed drive motor MF is less than 80% of the rated torque (step S350: "NO"), the processor 310 of the two-axis control device 300 determines whether the average torque transfer value TFA of the high-speed drive motor MF is between 30% and 80% of the rated torque (step S360).

[0059] If the average torque shift TFA of the high-speed drive motor MF is 30% or more but less than 80% of the rated torque (step S360: "YES"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in forward rotation (step S365). The forward rotation of the low-speed drive shaft SL (step S365) is a control that rotates the low-speed drive shaft SL in the forward rotation direction FR when the load on the high-speed drive shaft SF is moderate, thereby continuing the crushing process. In this embodiment, in the forward rotation of the low-speed drive shaft SL (step S365), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the forward rotation direction FR with a three-phase AC current at a frequency of 4.5 Hz. In this embodiment, the frequency (4.5Hz) used to control the low-speed drive motor ML during forward rotation (step S365) is lower than the frequency (60Hz) used to drive the high-speed drive motor MF during forward rotation (step S230 in Figure 4), and higher than the frequency (3Hz) used to control the low-speed drive motor ML during forward rotation (step S355). After instructing the low-speed inverter device IL to perform forward rotation of the low-speed drive shaft SL (step S365), the processor 310 terminates the low-speed shaft control process (step S300) shown in Figure 5.

[0060] If the average torque shift value TFA of the high-speed drive motor MF is 0% or more and less than 30% of the rated torque (step S360: "NO"), the processor 310 of the two-axis control device 300 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in forward rotation (step S375). The forward rotation of the low-speed drive shaft SL (step S375) is a control that rotates the low-speed drive shaft SL in the forward rotation direction FR when the load on the high-speed drive shaft SF is relatively low, thereby continuing the crushing process. In this embodiment, in the forward rotation of the low-speed drive shaft SL (step S375), the processor 310 instructs the low-speed inverter device IL to drive the low-speed drive motor ML in the forward rotation direction FR with a three-phase AC current at a frequency of 6 Hz. In this embodiment, the frequency (6Hz) used to control the low-speed drive motor ML during forward rotation (step S375) is lower than the frequency (60Hz) used to drive the high-speed drive motor MF during forward rotation (step S230 in Figure 4), and higher than the frequency (4.5Hz) used to control the low-speed drive motor ML during forward rotation (step S365). After instructing the low-speed inverter device IL to perform forward rotation of the low-speed drive shaft SL (step S375), the processor 310 terminates the low-speed shaft control process (step S300) shown in Figure 5.

[0061] According to the embodiment described above, overload of the high-speed drive shaft SF, which cannot be completely avoided by controlling the low-speed drive motor ML based on the rotation direction and rotation speed corresponding to the average torque transfer value TFA of the high-speed drive motor MF (steps S345, S355, S365, S375), can be avoided by controlling the low-speed drive motor ML based on the high-speed alarm signal AF, which is an overload alarm signal for the high-speed drive motor MF. As a result, sudden stops due to overload of the high-speed drive shaft SF can be prevented, making it easy to achieve both work efficiency and a safety factor.

[0062] The technologies disclosed herein are not limited to the embodiments, examples, and modifications described above, and can be implemented in various configurations without departing from the spirit thereof. For example, the technical features of the embodiments, examples, and modifications described above that correspond to the technical features of each form described in the summary of the invention may be replaced and combined as appropriate to solve some or all of the above-described problems or to achieve some or all of the above-described effects. Furthermore, technical features not described as essential in this specification may be deleted as appropriate.

[0063] In the above-described embodiment, the crusher 10 performs crushing by driving the high-speed drive shaft SF in the forward direction FR at a constant rotational speed, while driving the low-speed drive shaft SL in the forward direction FR at three rotational speeds corresponding to the average torque movement value TFA. In other embodiments, the crusher 10 may perform crushing by driving the high-speed drive shaft SF in the forward direction FR at multiple rotational speeds corresponding to the average torque movement value TFA. Alternatively, the crusher 10 may perform crushing by driving the low-speed drive shaft SL in the forward direction FR at a constant rotational speed. Furthermore, the crusher 10 may perform crushing by driving the low-speed drive shaft SL in the forward direction FR at two or four or more rotational speeds corresponding to the average torque movement value TFA.

[0064] Furthermore, the inverter devices 410 and 420 may delay the timing at which they begin outputting the high-speed alarm signal AF to the two-axis control device 300. This suppresses the instantaneous execution of the forward rotation operation of the low-speed drive motor ML based on the high-speed alarm signal AF (step S355 in Figure 5). As a result, the work efficiency of the crushing process can be improved.

[0065] Furthermore, the frequency of the reverse operation (steps S325, S335) of the low-speed drive motor ML can be set appropriately according to the configuration of the crusher 10. [Explanation of Symbols]

[0066] 10... Crusher 110… Processing container 112...Intake port 118…Discharge port 210,220… Rotation axis 212,222… Crushing blades 214,224… Spacer 300...Two-axis control device 310… Processor 320...memory 410, 420… Inverter devices 412,422… processors 414,424...memory 415,425…Converter circuits 416,426… Inverter circuits 417,427…Voltage Sensor 418,428… Current Sensor 510, 520… Drive motors 512, 522… Output shaft 610,620...Reducer 810...Waste 820... Fragments

Claims

[Claim 1] A first crushing blade is provided on the outer circumference of a first rotating shaft, A second rotating shaft is arranged parallel to the first rotating shaft, and a second crushing blade is provided on its outer circumference, A two-axis control device that controls the movement of the first rotation axis and the second rotation axis, Equipped with, A crusher that crushes waste fed between the first crushing blade and the second crushing blade by rotating the first and second rotating shafts in the forward direction, The two-axis control device, when the average first torque movement value output to the first rotating shaft is less than a set value and the first rotating shaft is driven in the forward direction at a constant rotational speed while the second rotating shaft is driven in the forward direction, controls the first rotating shaft to be driven in the forward direction at a constant rotational speed while the second rotating shaft is driven in the reverse direction when the average first torque movement value changes from less than the set value to or greater than the set value, and then controls the first rotating shaft to be driven in the forward direction at a constant rotational speed while the second rotating shaft is driven in the forward direction again when the average first torque movement value changes from greater than or equal to the set value to less than the set value.

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