JP5682826B2 - centrifuge - Google Patents

Description

  The present invention, in a centrifuge capable of rotationally driving various different rotors, accurately measures the rotor's moment of inertia or rotational energy to control the rotational speed of the rotor during centrifugation, so that any single failure can occur. The present invention relates to a centrifuge that limits the rotational energy of a rotor within the containment energy of a centrifuge even if it occurs.

  The centrifuge has a rotational speed that does not exceed the inherent mechanical strength of the rotor or the containment energy of the centrifuge so that even if a single failure occurs and the rotor breaks, the debris can be contained without popping out. Restriction is required.

  There are over 50 types of rotor families that can be used in combination with one centrifuge, and the maximum allowable rotational speed of each rotor and the rotational energy at the maximum allowable rotational speed vary. On the other hand, the centrifuge body has a drive capability capable of rotating the fastest rotor in the rotor family, so the rotor is equipped with an ID tag indicating the type of rotor or a signal generator indicating the maximum allowable rotation speed, A mechanism that does not rotate at a rotational speed exceeding the mechanical strength or the containment energy of the centrifuge is provided. If the rotor family of the centrifuge is a rotor that does not have its own type or maximum allowable rotational speed, the centrifuge has a function to measure the rotor's moment of inertia or rotational energy, and the rotor It prevents rotation at a rotational speed that exceeds the inherent mechanical strength or the containment energy of the centrifuge.

  When measuring the moment of inertia or rotational energy of the rotor, the output torque of the motor is kept as constant as possible during the measurement to improve the measurement accuracy. For example, Patent Document 1 discloses a configuration in which the motor current / motor voltage being measured is taken in and the output torque of the motor is corrected to correct the true motor output torque being measured. As shown in Patent Document 1, in order to improve the measurement accuracy when measuring the moment of inertia or rotational energy of the rotor, the motor current and output are changed by changes in motor slip, voltage, winding temperature, etc. As a means of correcting that the torque linearity is lost and the torque used for calculation deviates from the true motor output torque, the regression analysis is performed on each element of the motor current, the inverter DC link voltage, and the angular acceleration during rotation in advance. There is a technology that determines the contribution ratio of elements and corrects the output torque of the motor.

  Further, as shown in Patent Document 2, a control device for detecting motor current, inverter DC link voltage, and motor rotation speed is provided in duplicate, and each control device is changed from an inverter converter to a motor that rotates a rotor. The voltage supply paths of the motors are provided with shut-off functions that are arranged independently of each other, and each control device corrects the output torque of the motor to obtain the rotational energy of the rotor, and compares this with the rotational energy limit value to compare the energy with the rotor. There is a technology that outputs a shut-off operation signal when it is determined that the rotational energy limit value is exceeded.

JP 2005-230750 A Japanese Patent Laid-Open No. 2005-230751

  There are two types of identification signs equipped on the rotor in the rotor family used in combination with one centrifuge, one is an ID tag that indicates the type of rotor, and one is a signal that indicates the maximum allowable rotational speed. It is a vessel. The rotors currently on the market are equipped with both of the above-mentioned identification marks. Even if the rotor breaks at the predetermined rotational speed of the rotor, the rotor is centrifuged and rotated so as not to exceed the containment energy inside the centrifuge. It is configured to set the speed.

  However, an old design rotor or a rotor that cannot be equipped with an ID tag due to the shape unique to the rotor is equipped only with a signal generator indicating the maximum allowable rotation speed, and some rotors are within the maximum allowable rotation speed. If broken, the new centrifuge must be carefully controlled so as not to exceed the containment energy guaranteed by the centrifuge, and the maximum allowable rotational speed of the rotor depends on the signal generator signal. Instead, it is desirable to set it within the containment energy on the centrifuge side.

  Some older rotors are not equipped with both the ID tag and the signal generator indicating the maximum allowable rotational speed. In that case, the old rotor cannot be used as it is. However, if the old rotor can be used by some device on the centrifuge side, for example, a new protection technique, it is possible to operate without discarding the expensive rotor.

  To automatically reset the maximum allowable rotational speed of the rotor within the containment energy on the centrifuge without relying on the signal from the signal generator, calculate the rotor inertia moment or rotational energy with high accuracy. There is a need to. Further, in the calculation, in order to correct the actual output torque of the motor which is the largest cause of the measurement error, it is necessary to realize a technique for accurately correcting this.

  The present invention has been made in view of the above-described background, and an object thereof is to provide a centrifuge capable of safely using both new and old rotors regardless of the presence or absence of ID information.

    Another object of the present invention is to automatically calculate the rotational speed of the rotor centrifuge so that it does not exceed the containment energy guaranteed by the centrifuge when the rotor without ID information is operated with a new centrifuge. An object of the present invention is to provide a centrifuge having the function of:

  Still another object of the present invention is to calculate the actual output torque of the motor that causes the largest measurement error when calculating the inertia moment or rotational energy of the rotor with high accuracy. It is an object of the present invention to provide a centrifuge capable of accurately correcting from each element of angular acceleration.

  Still another object of the present invention is to accurately and beforehand identify the correction of the actual output torque of the motor that causes the largest error in calculating the inertia moment or rotational energy of the rotor with high accuracy. It is to provide a centrifuge.

  The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.

  According to one aspect of the present invention, a rotor that holds a sample and is detachably mounted, a motor that rotates the rotor, an inverter converter that outputs an AC voltage of variable frequency to the motor, and a rotation that houses the rotor A centrifuge having a chamber, an ID detector for reading ID information attached to the rotor, a speed detector for detecting the rotational speed of the rotor or the motor, and a control device for controlling the operation of the centrifuge The apparatus reads the ID information when the motor is started and the rotor is rotated, and if the ID information cannot be detected, the inertia moment of the rotor is calculated from the signal output of the speed detector before the rotor reaches the set rotational speed, The limiting rotational speed threshold value is obtained from the moment of inertia. When the set centrifugal rotation speed is less than or equal to the limit rotation speed threshold, the control device accelerates and stabilizes the rotor rotation to the set rotation speed, and the set centrifugal rotation speed exceeds the limit rotation speed threshold. Controls to stop the rotation of the rotor. The ID detector is, for example, a signal generator such as a Hall IC that detects the maximum allowable rotation speed of the rotor by detecting the magnetism of a magnet arranged in the rotor, and / or an identification hole (hole pattern provided in the rotor). The signal generator for detecting the rotor model number can be used.

  According to another feature of the present invention, a current detector for detecting the current of the motor and a DC voltage detector for detecting the DC power supply voltage of the inverter converter are provided, and the control device causes the rotor to have a predetermined torque. The product of the current detected by the current detector and the DC power supply voltage detected by the DC voltage detector is divided by the rotational speed of the motor detected by the speed detector, and this is set to a predetermined torque constant. The moment of inertia of the rotor was calculated by multiplying by. Further, a storage means is provided in the control device, and the value of the torque constant is stored in the storage means in advance. The limit rotational speed threshold calculated by the control device is set to be equal to or lower than the maximum allowable rotational speed unique to the rotor.

  According to still another aspect of the present invention, the control device accelerates the rotor from the first rotation speed to the second rotation speed, and the inverter current converter includes an average current of the motor by the current detector and an inverter converter by the DC voltage detector. The moment of inertia is calculated by multiplying the torque constant based on the average DC power supply voltage and the average rotational speed of the rotor or motor by the speed detection means. Then, the control device controls the inverter converter so that the output torque of the motor becomes a constant value, and accelerates the rotor from the first rotational speed to the second rotational speed. Further, when the rotor accelerates and reaches the second rotational speed, the control device controls the inverter converter so that the output torque of the motor becomes zero, and the rotor is changed from the second rotational speed to the third rotational speed. Decelerate and measure the rate of change of the rotational speed when the rotor or motor is decelerated by the speed detection means, and obtain the inertia moment of the rotor based on the motor output torque correction value and the rate of change of the rotational speed during deceleration I did it.

  According to still another aspect of the present invention, a rotor that holds a sample and is detachably mounted, a motor that rotates the rotor, an inverter converter that outputs an AC voltage having a variable frequency to the motor, and an electric current of the motor. First and second current detectors for detection, first and second DC voltage detectors for detecting the DC power supply voltage of the inverter converter, and first and second for detecting the rotational speed of the rotor or motor. Speed detection means, and first and second control devices, the first control device comprising: a motor current averaged by the first current detector; and a direct current of the inverter converter by the first DC voltage detector. The product of the average power supply voltage divided by the rotational speed based on the average rotational speed of the rotor by the first speed detector for detecting the rotational speed of the motor is multiplied by a predetermined torque constant to obtain the inertia moment of the rotor. The second control device detects the rotational speed of the motor by the product of the average current of the motor by the second current detector and the average voltage of the DC power of the inverter converter by the second DC voltage detector. A centrifugal separator that obtains the moment of inertia of the rotor by multiplying by a predetermined torque constant the value obtained by dividing the rotation speed based on the average rotation speed of the rotor by the second speed detector.

  According to still another aspect of the present invention, the first control device includes user interface means that allows an operator to arbitrarily set a set rotational speed of the rotor, and the rotor centrifuge is calculated from the calculated rotor inertia moment. The limit rotational speed threshold value below the containment energy and the set rotational speed threshold value lower than the limited rotational speed threshold value are obtained, and when it is determined that the limited rotational speed threshold value has been exceeded, a shut-off operation signal is output to the inverter to the motor from the inverter converter. Is turned off, and when it is determined that the rotational speed of the rotor exceeds the set rotational speed threshold, the rotational speed of the rotor is controlled below the set rotational speed threshold. The second control device obtains a limit rotational speed threshold value equal to or less than the containment energy of the rotor centrifuge from the calculated rotor inertia moment, and outputs a shut-off operation signal to the inverter when determining that the limit rotational speed threshold value is exceeded. Shut off the voltage supply to the motor from the inverter converter. The centrifuge includes a first shut-off device and a second shut-off device that shut off the voltage supply from the inverter converter to the motor, which are arranged independently of each other in the voltage supply path from the inverter converter to the motor. When the controller determines that the limit rotational speed threshold has been exceeded while the rotor is rotating at an arbitrary rotational speed, it outputs a shut-off operation signal to the first shut-off device and supplies voltage from the inverter converter to the motor. Shut off. The second control device outputs a shut-off operation signal to the second shut-off device when determining that the limit rotational speed threshold has been exceeded while the rotor is rotating at an arbitrary rotational speed, and outputs the shut-off operation signal to the motor from the inverter converter. Cut off the voltage supply.

  According to still another feature of the present invention, a communication means is provided between the first control device and the second control device, the first control device controls the inverter converter and the first control device via the communication means. The time of the measurement of the moment of inertia of the rotor with the control device 2 was synchronized. The first control device decelerates the motor when determining that the communication with the second control device is abnormal, and the second control device determines that the communication with the first control device by the communication means is abnormal. When this occurs, a shutoff operation signal is output to the second shutoff device. The first control device controls the inverter converter when it is determined that an error between the rotor inertia moment calculated by the first control device and the rotor inertia moment calculated by the second control device exceeds a predetermined value. Decelerate the motor.

  According to the invention of claim 1, since all the rotors of the rotor family in which the centrifuge can be used are automatically controlled to be equal to or lower than the containment energy guaranteed by the centrifuge, the expensive old rotor can be used. Can be used without being discarded.

  According to the invention of claim 2, since the control device accelerates the rotation of the rotor to the set rotational speed when the ID information can be correctly detected, and stops the rotation of the rotor when it is not valid, the control device guarantees with the centrifuge. Therefore, it is possible to prevent a centrifugal operation that may be loaded more than the contained containment energy from being performed.

  According to invention of Claim 3, an ID detector is a signal generator which detects the magnetism of the magnet arrange | positioned at a rotor, or / and a signal generator which detects the presence or absence of the identification hole provided in the rotor. Therefore, it is possible to easily detect ID information related to the rotor only by starting the rotor at a very low rotation.

  According to the invention of claim 4, the control device divides the product of the current detected by the current detector and the DC power supply voltage detected by the DC voltage detector by the rotational speed of the motor detected by the speed detector. Then, by multiplying this by a predetermined torque constant, the inertia moment or rotational energy of the rotor can be calculated with high accuracy. As a result, the necessity for designing a larger containment energy of the centrifuge in consideration of calculation errors is reduced, the protector of the centrifuge can be reduced in size, the strengthening of the door lock mechanism is reduced, the structure is simplified and It is possible to reduce the size of the centrifuge body and thus reduce the manufacturing cost of the centrifuge.

  According to the invention of claim 5, since the value of the torque constant is stored in the storage means in advance, the constant used for calculating the inertia moment or rotational energy of the rotor can be quickly acquired. Furthermore, even when the motor and the control device are exchanged at the site, the accuracy of calculation of the inertia moment or rotational energy of the rotor can be continuously maintained by re-teaching.

  According to the invention of claim 6, since the limit rotational speed threshold is set to be equal to or lower than the maximum allowable rotational speed unique to the rotor, the controlled rotational speed of the rotor is changed when the centrifuge shifts from acceleration to the settling state. Even if there is a characteristic of temporarily overshooting the set rotational speed, the limit rotational speed threshold is not exceeded, so that the rotor can be operated stably.

  According to the seventh aspect of the invention, since the moment of inertia is calculated when the rotor is accelerated from the first rotation speed to the second rotation speed, a highly accurate inertia moment value based on the actual measurement value can be obtained. And a highly reliable centrifuge can be realized.

  According to the invention of claim 8, the control device controls the inverter converter so that the output torque of the motor becomes a constant value and accelerates the rotor from the first rotation speed to the second rotation speed. The calculation accuracy of the moment of inertia of the rotor is improved, and the rotation speed of the rotor can be limited for any single failure.

  According to the ninth aspect of the invention, since the moment of inertia is calculated when the rotor is decelerated from the second rotation speed to the third rotation speed by inertia, a highly accurate inertia moment value based on the actual measurement value is obtained. And a highly reliable centrifuge can be realized.

  According to the invention of claim 10, the first and second speed detecting means for detecting the rotational speed of the rotor or the motor and the first and second control devices are provided, and the two control devices independently. Since the moment of inertia is calculated, the reliability of the obtained moment of inertia value can be improved.

  According to the eleventh aspect of the invention, when the first and second control devices independently determine that the rotational speed of the rotor is set to exceed the set rotational speed threshold, the rotor speed falls below the set rotational speed threshold. Since the rotation speed is controlled, it is possible to reliably prevent the rotor from rotating beyond the containment energy on the centrifuge side.

  According to invention of Claim 12, the 1st interruption | blocking apparatus and 2nd interruption | blocking apparatus which interrupt | block the voltage supply to the motor from the inverter converter arrange | positioned mutually independently in the voltage supply path from an inverter converter to a motor Since these are independently controlled by the first and second control devices, a centrifuge with double safety can be realized.

  According to the invention of claim 13, since the first control device controls the inverter converter and synchronizes the time with respect to the measurement of the moment of inertia of the rotor with the second control device via the communication means, Even if an abnormality occurs in the measurement result of one of the control devices due to the occurrence of an error, the abnormality can be detected early.

  According to the invention of claim 14, the first control device decelerates the motor when it is determined that the communication with the second control device is abnormal. Restrictions can be possible.

  According to the fifteenth aspect of the present invention, the second control device outputs a shut-off operation signal to the second shut-off device when it is determined that communication with the first control device by the communication means is abnormal. It is possible to limit the rotational speed of the rotor even for a single failure.

  According to the sixteenth aspect of the present invention, when the first control device determines that the error of the main and sub inertia moments exceeds a predetermined value, the inverter is shut off, so that the safety measures can be taken reliably.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

It is a figure which shows the rotation control block of the motor of the centrifuge which concerns on the Example of this invention. FIG. 2 is a detailed block circuit diagram of a first control device 8 and a second control device 9 in FIG. 1. It is a circuit diagram of the inverter converter 3 of FIG. It is a figure which shows the change of the rotational speed of a rotor in the Example of this invention. It is a figure which shows the rotational speed of the rotor at the time of calculating the inertia moment or energy of a rotor in the Example of this invention. It is a figure which shows the inertia moment or energy calculation operation | movement of a rotor in simulation. It is a figure which shows the mode of speed in simulation. It is a figure which shows the database which calculates | requires a limiting rotational speed threshold value and a setting rotational speed threshold value from the calculated inertia moment. FIG. 3 is a flowchart of a rotor operation moment of inertia or energy measurement operation of the first controller. It is a moment of inertia measurement or energy measurement operation flow chart of a rotor of the 2nd control device. It is a flowchart figure of the electric power supply interruption | blocking operation | movement to the motor of a 1st control apparatus. It is a flowchart figure of the electric power supply interruption | blocking operation | movement to the motor of a 2nd control apparatus. It is the figure which illustrated the time of the teaching start of the operation screen which calculates | requires the constant coefficient k by teaching using a rotor with a known moment of inertia. It is the figure which illustrated the time of completion | finish of the teaching of the operation screen which calculates | requires the constant coefficient k by teaching using a rotor with a known moment of inertia. It is a figure which shows the change of the rotational speed of the rotor in the centrifugation operation | movement of a prior art example.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same part in the following figures, and repeated description is abbreviate | omitted.

  In the configuration of FIG. 1, the entire centrifuge according to the present invention is indicated by 100, 1 is a rotor for storing a sample, 2 is a three-phase induction motor or a DC brushless motor for driving the rotor 1 to rotate. In the embodiment, a description will be given below of a three-phase induction motor in which torque correction is more difficult. Reference numeral 13 denotes a torque transmitter such as a crown or a spud that transmits the drive torque of the drive shaft 14 to the rotor 1. Reference numeral 3 denotes an inverter converter that receives the AC power supply 4 and outputs a variable frequency voltage to the motor 2. Reference numeral 5 denotes first rotation speed detection means for the rotor 1 or the motor 2. It is a photo interrupter that outputs a pulse signal MPG depending on the presence or absence. Reference numeral 6 denotes a second rotational speed detection means comprising a magnet sensor such as a Hall element of the rotor 1 or the motor 2 and detects the presence or absence of at least one magnet 7 provided on the circumference of the bottom of the torque transmitter 13. The pulse signal SPG is output.

  Reference numeral 15 denotes a centrifuge frame, 10 denotes a bowl surrounding the surface of the rotor 1 supported by the frame 15, and 11 denotes a protector ring supported by the frame 15, which surrounds the bowl 10 and is centrifuged when the rotor 1 is broken. The debris of the rotor 1 that tries to jump out of the centrifuge according to the force is received. Reference numeral 12 denotes an openable / closable door. When the rotor 1 is rotating, a space for confining the rotor 1 is formed together with the protector ring 11 and the bowl 10.

  Reference numeral 16 denotes a first current detector that detects a U-phase primary current of the motor 2 and outputs a current signal Iu. Similarly, 17 detects a W-phase primary current of the motor 2 and outputs a current signal Iw. The current detectors 16 and 17 are, for example, current sensors that output a voltage along a current waveform using a Hall element in this case.

  Reference numeral 18 denotes a first DC voltage detector that detects a DC power supply voltage of the inverter converter 3 and outputs a voltage signal V1, and 19 similarly detects a DC power supply voltage of the inverter converter 3 and outputs a voltage signal V2. A second DC voltage detector 20 is a first shut-off device that shuts off the voltage supply from the inverter converter 3 to the motor 2 arranged in the voltage supply path from the inverter converter 3 to the motor 2. Reference numeral 21 denotes a second cutoff device serving as an inverter input cutoff device provided in a power supply path from the AC power supply 4 to the inverter converter 3. Reference numeral 8 denotes a first control device, which controls the inverter converter 3 by outputting a command value of a voltage to be output to the motor 2 to the inverter converter 3 from the inverter control unit 210 via the signal line 30; The moment of inertia of the rotor 1 according to the pulse signal MPG output from the first speed detection means 5, the current signal Iu output from the first current detector 16, and the voltage signal V1 output from the first DC voltage detector 18. Alternatively, rotational energy is measured. Reference numeral 9 denotes a second control device, which includes a pulse signal SPG output from the second speed detecting means 6, a current signal Iw output from the second current detector 17, and an output from the second DC voltage detector 19. The inertia moment or rotational energy of the rotor 1 is measured in accordance with the voltage signal V2.

  25 is a user interface means for allowing the operator to arbitrarily set the input of an identification code for selecting the type of rotor to be operated from the rotor table and the settling speed, operating time, set temperature, etc. of the selected rotor 1 It is. The centrifuge is preliminarily provided with a rotor table serving as rotor-specific information for various rotors. Each rotor table has a temperature correction coefficient, an allowable maximum rotational speed, energy at a predetermined rotational speed of the rotor, and a rotor. Information on energy Emax at the allowable maximum rotation speed is registered in advance. The operator can select one rotor from the user interface means 25 and can set the set rotational speed, operation time, and set temperature of the selected rotor. The rotational speed of the rotor 1, the operation time, the refrigerator not shown, and the like are controlled according to the set rotational speed of the rotor 1 input to the user interface means 25 via

  Japanese Patent Laid-Open No. 11-156245 discloses means for automatically obtaining information such as windage loss, moment of inertia, and maximum rotational speed from the rotor 1 from the automatic identification device, regardless of manual setting from the user interface means 25. An identification hole pattern 54 provided on the circumference of the lower surface of the rotor adapter 51 provided at the lower part of the rotor 1 and an eddy current sensor for detecting the presence or absence of the hole so that automatic acquisition by the rotor identification device as described above is possible 55, and the signal output of the eddy current sensor 55 is input to the first control device 8 via a signal converter 222 (see FIG. 2) described later as a rotor identification signal ID.

  Reference numeral 53 denotes a signal generator that indicates an allowable maximum rotational speed, which is composed of a magnet sensor such as a Hall element of the rotor 1 or the motor 2, and includes an arrangement of at least two or more magnets 52 provided on the circumference of the inner surface of the rotor adapter 51. Detect and output a pulse signal RPG. The pulse signal RPG is output to the first control device 8 and the second control device 9.

  In this embodiment, the first control device 8 and the first shut-off device 20 are connected by a signal line 22, and the first shut-off device 20 drives the motor 2 by the shut-off signal output from the first control device 8. Can be stopped. The second control device 9 and the second shut-off device 21 are connected by a signal line 23, and the second shut-off device 21 can stop the driving of the motor 2 by a shut-off signal output from the second control device 9. . Moreover, the 1st control apparatus 8 and the 2nd control apparatus 9 are connected by the communication line 24, and both control apparatuses can perform two-way communication between apparatuses by providing a communication means.

  FIG. 2 is a detailed block circuit diagram of the first control device 8 and the second control device 9 of FIG. In FIG. 2, the first control device 8 includes a CPU 201, a current effective value converter 202, a non-volatile memory 208 serving as a static RAM, an EEPROM non-volatile memory 223 that retains stored contents even when an applied voltage is lost, and an inverter. The control unit 210 is included. The second control device 9 includes a CPU 211, a current effective value converter 212, and an EEPROM nonvolatile memory 218 that retains stored contents even when the applied voltage is lost. The non-volatile memories 223 and 218 store information obtained by back-calculating the torque constant so that the moment of inertia matches the known moment of inertia of the rotor by teaching work. A commercially available microprocessor can be used as the CPU 201 and the CPU 211, for example, SH7080 series or H8 / 3048F series manufactured by Renesas Technology. These are built-in peripheral functions such as a multi-function timer pulse unit (hereinafter referred to as MTU), an A / D converter, a serial communication interface (hereinafter referred to as SCI), and an input / output port (hereinafter referred to as I / O). It is a processor. Note that the memory used is not limited to RAM or EEPROM, but may be realized by other storage means.

  The current effective value converter 202 converts the current signal Iu from the first current detector 16 into an effective value, inputs the output signal to the A / D converter 203 built in the CPU 201, and the current effective value converter 212 performs the second operation. The current signal Iw from the current detector 17 is converted into an effective value, and the output signal is input to the A / D converter 213 built in the CPU 211. The analog voltage input by the A / D converter 203 and the A / D converter 213 is converted into digital values, and the CPU 201 and the CPU 211 measure the primary current of the motor 2 based on these digital values. A blocking signal to the first blocking device 20 is output from the I / O 207 built in the CPU 201, and a blocking signal to the second blocking device 21 is output from the I / O 217 built in the CPU 211.

  The pulse signal MPG from the first speed detection means 5 is input to the MTU 204 built in the CPU 201, and the pulse signal SPG from the second speed detection means 6 is input to the MTU 221 built in the CPU 201 and also to the MTU 214 built in the CPU 211. The MTU 204 and MTU 214 measure the pulse periods of the pulse signals MPG and SPG, respectively, using the CPU internal clock. As for the two-phase pulse signals ENCa and ENCb output from the third speed detection means 26, ENCa is input to the MTU 205 built in the CPU 201, and ENCb is input to the MTU 215 built in the CPU 211. Similarly, the pulse periods of the pulse signals ENCa and ENCb are measured by the MTU 205 and MTU 215. Similarly, the pulse signal RPG is input to the MTU 230 built in the CPU 201 and the MTU 231 built in the CPU 211 and measured.

  The voltage signal V1 from the first DC voltage detector 18 is input to the A / D converter 206 built in the CPU 201, and the voltage signal V1 from the second DC voltage detector 19 is input to the A / D converter 216 built in the CPU 211. The analog voltage input by the A / D converter 206 and the A / D converter 216 is converted into a digital value, and the CPU 201 and the CPU 211 measure the DC power supply voltage of the inverter converter 3 based on these digital values.

  The inverter control unit 210 outputs a three-phase voltage command signal having a variable frequency to the inverter converter 3, and the CPU 201 detects the speed of the motor 2 from the pulse signal MPG or ENCa and performs inverter conversion via the inverter control unit 210. The device 3 is controlled. The first control device 8 and the second control device 9 can communicate with each other by connecting the SCI 209 built in the CPU 201 and the SCI 219 built in the CPU 211 via the communication line 24, and the first control device 8 and the second control device 9 can communicate with each other. The device 8 can monitor the operation state of the second control device 9 or the calculation result of the moment of inertia or energy of the rotor 1, and take a synchronous handshake of the measurement timing when measuring the moment of inertia or energy of the rotor 1. Can do.

In this embodiment, the pulse signals MPG and SPG are signals of 2 pulses per rotation of the motor 2, and the pulse signals ENCa and ENCb are signals of 30 pulses per rotation of the motor 2. The rotation speed N (min ⁻¹ ) of the rotor 1 and the motor 2 is measured by measuring the time between the falling edges of the pulse signal MPG by the MTU 204 built in the CPU 201, taking speed detection by the pulse signal MPG as an example. Specifically, each time the falling edge of the pulse signal MPG is calculated based on the count value of the internal clock of the CPU 201 from the previous falling edge to the occurrence of the current edge. Here, assuming that the frequency of the internal clock of the CPU 201 or the CPU 211 is F and the count number of the internal clock between the signal falling edges is CNT, the rotational speed N of the motor 2 is as shown in Equation 1. Small black circles in Equation 1 mean multiplication (the same applies to the following equations in this specification), and the numerator in Equation 1 means 60 × F.

 Note that the instantaneous current rotational speed Nr of the motor 2 which is a three-phase induction motor is influenced by the torque ripple of the 6th order and 12th order components that are multiple components of 3 of the excitation frequency, and the response when the voltage command is changed in the motor control. Thus, the motor 2 changes with respect to the ideal rotation speed No indicated by the wavy line in one rotation cycle tr, and the value of the speed gradient may change at the measurement timing (this is the solid line in FIG. 7). (It will be described later with Nr). For this reason, in the present embodiment, the speed to be obtained is subjected to filtering processing by software that sequentially updates the speed for each speed measurement so as to attenuate higher-order fluctuations in speed, and this speed Nn after filtering (described later) 7 is obtained by Equation 2 where Nn-1 is the previous speed after filtering, Nr is the measured current rotational speed, and α is the filtering constant.

  Here, α is a value smaller than 1, and the smaller the value, the more the damping effect can be expected. However, the time delay with respect to the actual speed represented by Δt in FIG. 7 also increases. Furthermore, this time delay becomes larger as the speed detection cycle is longer. In this embodiment, the speed detected by the CPU 201 and the CPU 211 is the third speed detecting means in which the number of pulses per rotation of the motor 2 is large and the speed update cycle is shortened so that the time delay in the filtering process can be minimized. 26 is obtained from the pulse signals ENCa and ENCb from No. 26, and the time delay is set to about 200 ms so that there is no problem in the rotational speed control of the centrifuge.

  In addition, since the rotor energy cannot be accurately measured when a failure in speed detection such as pulse loss of the pulse signals ENCa and ENCb occurs, the first controller 8 can detect the occurrence of such a failure. The speed obtained from the pulse signal MPG and the speed obtained from the pulse signal ENCa are compared, and similarly, the second controller 9 is configured to be able to compare the speed obtained from the pulse signal SPG and the speed obtained from the pulse signal ENCb.

  In addition, since the output signals of the RMS current value converters 202 and 212 input to the A / D converters 203 and 213 include high-order current ripple components, for example, the A / D converter 203 and the The A / D value is sampled at 213, and the same filtering process as software for speed detection is performed.

  Next, a detailed configuration of the inverter converter 3 will be described with reference to FIG. In the inverter converter 3, 312 is a converter that converts the AC power supply 4 into a DC power supply, and 311 is a smoothing capacitor that smoothes the power supply converted by the converter 312. Reference numerals 31, 32, and 33 denote inverter bridges that supply three-phase AC power to the motor 2. The inverter bridge includes an upper arm and a lower arm in which a free wheel diode is reversely connected to a switching element such as an IGBT or a MOSFET. In FIG. 3, an IGBT is used as a switching element, and the upper arm and the lower arm constituting the bridge on behalf of the inverter bridge 31 are indicated by 301 and 302, and 304 and 306 are gate controls for the upper arm 301 and the lower arm 302, respectively. These are circuits, and a lonely signal is sent from the photocouplers 305 and 307. Reference numeral 310 denotes a power source for turning on the light emitting elements of the photocouplers 305 and 307, and the first coupler 20 including the semiconductor switch such as a transistor or a three-state gate and the resistors 308 and 309, and the photocouplers 305 and 307. It is connected to the anode side of the light emitting element. The on / off signal of each bridge output from the inverter control unit 210 is sent to the cathode side of the light emitting elements of the photocouplers 305 and 307 via the drivers 316 and 317, and the upper arm 301 and the lower arm 302 are respectively connected to the inverter control unit 210. Turns on when the output signal becomes LOW level.

  In addition, a relay contact 313 that is turned on and off in accordance with an excitation signal from the relay coil 314 is provided between the AC power supply 4 and the converter 312, and a second cutoff device including a semiconductor switch such as a relay coil 314 transistor or a three-state gate. 21 is connected to the power source 310 via the control terminal 21, and the control signal of the inverter control unit 210 is sent to the cathode side via the driver 318. Here, when the first shutoff device 20 is shut off by the signal line 22, the power supply to the light emitting elements of the inverter bridges 31, 32, 33 is cut off, so that the inverter control unit 210 is turned on to drive the motor 2. Even if the off signal is output, all the bridges cannot be turned on, and the voltage supply for driving the motor 2 is cut off. Similarly, when the second breaking device 21 is turned off by the signal line 23, the relay contact 313 is turned off even if the inverter control unit 210 outputs a control signal for turning on the relay contact 313 to drive the motor 2. As a result, the power supply from the AC power supply 4 to the inverter converter 3 is cut off, and the power supply to the motor 2 is also cut off.

  Next, the operation of the centrifuge 100 of the present embodiment will be described using the flowchart of FIG. First, the user arbitrarily selects the rotor 1 and attaches it to the centrifuge 100. Thereafter, in step 401, the operation rotational speed of the rotor 1 is set by inputting it from an operation unit (not shown) of the centrifuge 100. Next, in step 401, other conditions necessary for the centrifugal operation such as the set temperature of the rotor 1 and the operation time of the centrifugal separation are set by inputting from the operation unit. When the input of the conditions for centrifugation is completed, the operator closes the door 12 of the centrifuge 100 and presses the START key from the operation unit (step 403), whereby the motor 2 is started in step 404. Next, at step 405, in the low rotation region where the rotation speed is about 50 rotations per minute, a signal for identifying the rotor 1 and a signal indicating the limit rotation speed are determined from the presence or absence of the outputs of the signal generator 53 and the eddy current sensor 55. To detect. Usually, when the identification signal of the rotor 1 is detected, the ID of the rotor 1 can be recognized, and therefore the type of the rotor 1, the limited rotational speed Ns of the rotor alone, and the like are known from the data stored in the centrifuge 100 in advance. Further, according to the signal indicating the limiting rotational speed, the allowable rotational speed of the rotor alone can be determined by measuring the appearance interval of the signal from the signal generator 53.

  Next, in Step 406, the first control device 8 determines whether or not there is an identification signal. If there is, the type of the rotor 1 is specified from the rotor table (not shown), and the rotational speed limit of the rotor 1 is determined. (Allowable maximum rotation speed) Ns is set and compared with the set rotation speed input in step 401. If the set rotation speed is equal to or less than the allowable maximum rotation speed, in step 409, centrifugation is performed for a predetermined time under predetermined conditions. Do the driving. Since this centrifugation operation may be performed by a publicly known method, detailed explanation here is omitted. Next, in step 410, the first control device 8 determines whether or not the rotational speed of the rotating rotor 1 is equal to or lower than the limit rotational speed Ns set in step 408. If it is equal to or less than the limit rotational speed Ns, it is determined whether the operation time set in step 411 has ended and the centrifugal separation operation has ended.

  When the rotational speed of the rotor 1 exceeds the limit rotational speed Ns at step 410 or when the centrifugal separation operation is finished at step 411, the rotor 1 is decelerated at step 412 and the process is finished (step 412). Steps 401 to 412 described above are the operation procedure of the normal centrifuge 100. In the conventional centrifuge, if there is no identification signal in step 406, the centrifuge operation is stopped.

  In this embodiment, even if it is determined that there is no identification signal (ID) in step 406, the centrifugal operation can be continued by executing steps 413 to 414. In step 413, it is determined whether or not there is an RPG signal. What can be determined by the RPG signal is the maximum allowable rotational speed unique to the rotor 1. This allowable maximum rotational speed is a rotational speed number determined in consideration of centrifugal stress applied to the rotor 1 and the allowable rotational speed of the rotor 1 considering the containment energy of the centrifuge 100 (usually, this allowable rotational speed). Does not always match). If there is no RPG signal, step 415 for calculating the moment of inertia or energy of the rotor 1 is executed. The detailed procedure of step 415 will be described later. Next, based on the calculated numerical value, the first control device 8 sets a limit rotational speed Ns, and the process proceeds to step 409.

  As described above, even if an old-style rotor having no ID information is attached to the centrifuge 100, the inertia moment or energy is measured after the rotor 1 is started and before the settling state is reached, so that the safe restriction is achieved. Since the rotation speed Ns is obtained, an old-style rotor can be used, and a user-friendly centrifuge can be realized.

If there is an RPG signal in step 413, it is determined in step 414 whether the allowable rotational speed specific to the rotor 1 determined by the RPG signal is less than 7000 min ⁻¹ . Here, when it is less than 7000 min ⁻¹ , the process proceeds to step 409 to start a normal centrifugal separation operation. This is because any rotor mounted at a rotational speed of less than 7000 min ⁻¹ falls within the containment energy of the centrifugal separator 100, so there is no need to bother to calculate the inertia moment or energy of the rotor 1. It is. The containment energy in the centrifuge 100 is greatly affected by the structure itself including the bowl 10 and the door 12 of the centrifuge 100, and therefore is not necessarily constant. It is different for each type of centrifuge 100.

When the allowable maximum rotational speed unique to the rotor 1 determined by the RPG signal in step 414 is 7000 min ⁻¹ or more, the process proceeds to step 415 to execute step 415 for calculating the moment of inertia or energy of the rotor 1. Next, based on the calculated numerical value, the first control device 8 sets a limit rotational speed Ns, and the process proceeds to step 409. In this way, when the allowable maximum rotational speed inherent to the rotor 1 is 7000 min ⁻¹ or more, depending on the type of rotor, there is a risk of exceeding the containment energy in the centrifuge 100, so the inertia moment or energy of the rotor 1 is calculated. The safe moment of inertia or energy was calculated.

Next, an example of an inertia moment or energy calculation operation of the rotor 1 will be described with reference to FIGS. The conventional centrifuge is operated as shown in the graph showing the relationship between the elapsed time (seconds) and the rotational speed of the rotor 1 in FIG. At time t = 0, the rotation of the motor is started, and a rotor identification signal and a limit rotation speed signal are detected in a low rotation region (for example, around 50 min− ¹ ) indicated by an arrow 1501. Thereafter, the rotation of the rotor is accelerated and set at a predetermined rotational speed as indicated by an arrow 1502, and the operation is performed for the centrifugation time set as indicated by an arrow 1503. When centrifugation for the set time is completed, the rotor is decelerated as indicated by an arrow 1504 and stops rotating.

Here, in the conventional centrifuge, when the rotor identification signal and the limit rotation speed signal cannot be detected in the low rotation region indicated by the arrow 1501, the rotation of the rotor is stopped as an error and the centrifugal separation operation is stopped. . In the present embodiment, a state in which the rotation of the rotor stops is avoided and a centrifuge capable of safely guaranteeing the centrifuge operation is realized, and the operation state is shown in FIG.

FIG. 5 is a graph showing the relationship between the elapsed time (seconds) and the rotation speed of the rotor 1 when there is no ID information such as an identification signal and a limit rotation speed signal in the rotor 1 in this embodiment. The centrifuge 100 according to the present embodiment detects the rotor identification signal and the limit rotation speed signal in the low rotation region indicated by the arrow 501. If the identification signal and the limit rotational speed signal of the rotor 1 cannot be detected here, the rotation of the rotor 1 is further accelerated, and the inertia of the rotor 1 indicated by step 415 in FIG. Calculate moment or energy. In this embodiment, the predetermined low-speed rotation region uses a rotation region of about 2000 min ⁻¹ . Thereafter, if the set rotational speed for the centrifugal separation operation is equal to or lower than the limit rotational speed Ns obtained in step 416, the rotor 1 is further accelerated as indicated by an arrow 503, and at the set rotational speed as indicated by an arrow 504. Centrifugation operation is performed for a set time, and when the set time has elapsed, the rotor 1 is decelerated and stopped as indicated by an arrow 505. If the rotational speed for centrifugation set in step 402 is larger than the limited rotational speed Ns calculated in the predetermined low speed rotational area indicated by the arrow 502, the rotor 1 is decelerated as indicated by a dotted line 506. And stop its rotation.

  Next, how to calculate the moment of inertia or energy of the rotor 1 near the arrow 502 in FIG. 5 will be described with reference to FIG. In FIG. 6, the solid line represents the current rotational speed N of the rotor 1 and the motor 2, and the one-dot broken line represents the output torque τa and τm of the motor 2.

  The first control device 8 reduces the output torque of the motor 2 from τa to τm in order to avoid the measurement in the rapid acceleration state of the rotor having a small moment of inertia at the time T1 when the rotational speed N1 is being accelerated. Control is performed, and the state in which the output torque is reduced is maintained until time T3 so that the speed gradient and the current value can be detected as constant values in the speed detection and current detection filtering processes described above. The rotation speed at the measurement start time T2 at the torque τm is N2 (first rotation speed), and at the measurement end time T3 at the torque τm, the rotation speed reaches N3 (second rotation speed).

  From time T3, the first control device 8 sets the output torque to zero, enters a natural deceleration state according to the deceleration torque τw due to the windage loss of the rotor 1 or the support system mechanical loss such as the bearing of the motor 2, and delays the speed detection filtering processing time In consideration of the above, the natural deceleration state is maintained until the measurement start time T4, the natural speed is further reduced from the rotational speed N4 at T4, and the rotational speed is reduced to the rotational speed N5 (third rotational speed) at the measurement end time T5.

The rotational speed of the motor 2 in the acceleration state from time T2 to T3 is Nf, the inertia moment of the rotor 1 to be calculated is Ip, the rotor of the motor 2, the rotational shaft other than the rotor 1 such as the drive shaft 14 and the torque transmitter 13 Assuming that the moment of inertia is Ir, Ir is expressed by the following mathematical formula 3, which is a known fixed amount of about 0.00139 kg · m ² which is a constant in this case.

  On the other hand, the rotational speed of the motor 2 in the natural deceleration state from time T4 to T5 is represented by the following formula 4 as Nb.

  In Equations 3 and 4, the temporal change rates of the rotational speeds Nf and Nb of the motor 2 may be expressed as Equations 5 and 6 approximately because the time difference Δtf = T3−T2 and the time difference Δtb = T4−T5 may be used. .

数式４、数式５、数式６を数式１に代入してロータ１の慣性モーメントＩｐについて整理すると、数式７を得る。

By substituting Equation 4, Equation 5, and Equation 6 into Equation 1 and rearranging the inertia moment Ip of the rotor 1, Equation 7 is obtained.

Here, the range of the inertia moment Ip of the rotor 1 to be calculated ranges from about 100 × 10 ⁻⁴ kg · m ^{2 to} about 4000 × 10 ⁻⁴ kg · m ² at the minimum and about the moment of inertia value. There is a 40-fold difference in ratio. In particular, when the motor 2 is an induction motor, empirically, the excitation slip varies depending on the magnitude of the inertia moment of the rotor 1, and if it has a small Ip, it tends to be apparently large and the error tends to be large.

  Since the motor control changes the magnitude and frequency of the motor voltage at a constant cycle, the instantaneous slip changes with the magnitude of the inertia moment Ip of the rotor to be handled, and further the voltage of the smoothing capacitor 311 and the winding of the motor 2 Since the linearity of the motor current and the output torque is lost due to the change in the primary winding resistance due to the temperature change, the output torque τm of the motor 2 is approximated by Equation 8 in the centrifuge of this embodiment.

  The meaning of Equation 8 is that if the unit is W (Watt), the right side is the product of the output torque τm and the average rotational speed Nav of the motor 2 between the time difference Δtf between the times T2 and T3, The left side is the product of the average value Iuav of the effective current of the current signal Iu input to the motor 2 with a constant coefficient k and the average value V1av of the voltage of the smoothing capacitor 311, that is, the voltage signal V1 of the DC link voltage, and these are short. Since the efficiency hardly changes with the time difference Δtf, the constant coefficient is balanced using k. The rotational speed Nav is an intermediate speed between the rotational speed N2 at time T2 and N3 at time T3, and is given by Equation 9.

    When formula 8 is arranged with respect to the torque τm of the motor 2, formula 10 is obtained, and when this is substituted into formula 7, formula 11 is obtained.

Next, details of the operations of the first control device 8 and the second control device 9 in the inertia moment calculation operation of the rotor 1 will be described with reference to FIGS. 9 and 10. FIG. 9 is an operation flowchart of the CPU 201 in the first control device 8, and FIG. 10 is an operation flowchart of the CPU 211 in the second control device 9. In addition, when calculating | requiring the rotational energy Eav in the rotational speed Nav of the rotor 1 instead of the inertia moment Ip of the rotor 1, if the rotational speed at the time of Eav measurement of the rotor 1 is Nav (min < ^-1 >), if Formula 12 is used, good.

  In the conventional method in which the current signal Iu input to the motor 2 and the voltage signal V1 of the DC link voltage as the torque fluctuation factors are used as the torque fluctuation factors for the output torque τm during operation, the moment of inertia is about ± 8%. It can be covered only with the calculation accuracy of Ip or rotational energy E.

  This is because the difference in the magnetic flux due to the inherent air gap length of the motor 2, the difference in the original winding resistance, and the amount of magnetic flux output from the magnet is different if the motor 2 is a brushless DC motor. The fact that it cannot be excluded is one of the factors that cause an error, and the constant coefficient k is a specific numerical value that varies depending on a control device such as a motor or an inverter mounted on the centrifuge 100. Therefore, this variation is eliminated by determining the constant coefficient k by teaching. By performing the calculation method of Formula 11 or Formula 12 and teaching the coefficient k, the calculation error of the inertia moment Ip or the rotational energy E can be increased to a value of ± 3%. In Equation 11 or Equation 12, if the calculated inertia moment Ip is a known value, the constant coefficient k can be calculated by using the inertia moment calculation process as it is.

  A method of teaching the constant coefficient k will be described with reference to FIGS. In FIG. 13, for example, an R15A rotor sold by the applicant is selected by a rotor selection button 1300. Selectable rotors can be selected from most or all of the rotor families that can be used in this centrifuge, and moment of inertia values are entered as a database for each, allowing on-site teaching. If the rotor 1 is of the same type, there is almost no difference in the moment of inertia because of its nature, that is, it is made of an alloy and machined with high precision.

  Next, when the start button 1301 is pressed, an operation similar to the moment of inertia calculation or rotational energy calculation described later is performed, and rotational speeds N2, N3 and below Nav are measured, and a constant value as shown in FIG. The coefficient k is obtained. The constant coefficient k can be increased in accuracy by obtaining an average value by a plurality of operations. Thereafter, by pressing the confirm button 1302, the CPU 201 of the first control device stores the coefficient k of the calculated constant in the nonvolatile memory 223, and the CPU 211 of the second control device stores the calculated constant coefficient k in the nonvolatile memory 218. Thereafter, when the actual moment of operation of the centrifuge is calculated, the moment of inertia Ip or the rotational energy E is calculated using Equation 11 or Equation 12 and is read out and used.

  In FIG. 9 showing the operation of the CPU 201, step 700 is a determination process for determining whether the speed of the motor 2 has reached N1 (see FIG. 6). If it is N1 or more, the process proceeds to step 701, and the CPU 201 indicates that the CPU 211 is normal. In order to check whether the CPU 211 is operating, communication for inquiring about the current state of the CPU 211 is performed. In step 702, the presence or absence of a response to the communication in step 701 from the CPU 211 is checked. If there is no response, the CPU 211 determines that there is an abnormality. In step 703, the motor 2 is decelerated and stopped, and the measurement ends.

  If there is a response, the process proceeds to step 704, where the motor slip and the motor applied voltage are reduced to predetermined values, and the output torque of the motor 2 is reduced to τm. After that, as described above, in step 705, during the time tx from time T1 to T2 in FIG. 6, so that the speed gradient and current value after speed detection and current detection filtering processing can be detected in a stable state, An interval for maintaining the state where the output torque is reduced is set, and in step 705, a notification of acceleration start is communicated to CPU 211 so that the CPU 201 and CPU 211 are synchronized with respect to the measurement of rotational speed N2, and rotational speed N2 is measured in step 706. To do.

  Step 707 is continued for a predetermined time interval ty in the acceleration state of torque τm, and the process proceeds to step 709. In step 709, it is determined whether or not the rotational speed N2 has been accelerated after measuring the rotational speed N2. If the rotational speed has not accelerated more than the increased rotational speed ΔNx, the inverter control unit 210 is controlled to maintain the current acceleration until it increases by ΔNx or more.

  If the acceleration is more than ΔNx, the process proceeds to Step 710, where the rotational speed N3 and the time difference Δtf required for the acceleration from N2 to N3 at this time are measured and the temporal change in the rotational speed when accelerating with the torque τm. The rate dNf / dt is calculated according to Equation 5, and the average value, Iuav, V1av, and the average rotational speed Nav of the motor 2 between the times T2 and T3 between the current signal Iu and the smoothing capacitor voltage V1 are obtained. Here, the time difference Δtf is the time from time T2 to time T3 in FIG. Step 712 is a process for stopping the power supply to the motor 2 and starting the natural deceleration at a torque of 0. The process proceeds to step 713, and the time delay of the speed detection filtering process is taken into consideration so that the speed gradient can be detected in a stable state. 6, a time interval of zero torque is set for a time tz from time T3 to T4 in FIG. 6, and in step 714, the CPU 211 and 211 are notified of the start of deceleration so as to synchronize the measurement of the rotational speed N4 of the CPU 201 and 211 In step 715, the rotational speed N4 is measured.

  In step 716, it is determined whether or not the motor 2 is decelerating by a reduction rotational speed ΔNy after the rotational speed N4 is measured. If the reduced rotational speed is not decelerating more than ΔNy, the inverter control unit 210 is controlled to maintain the current decelerating state until decelerating more than ΔNy. If the vehicle is decelerated by ΔNy or more, the process proceeds to step 717. In step 717, the rotational speed N5 at this time and the time difference Δtb (= time from time T4 to T5) required for deceleration from N4 to N5 are measured.

  In step 717, since the measurement of the item for calculating the moment of inertia or rotational energy of the rotor 1 is completed, the process of increasing the output torque of the motor 2 to τa for rapid acceleration is performed, and the time of the rotational speed at the time of natural deceleration The change rate dNb / dt is calculated by the following equation 6.

  In step 719, each measurement result is substituted into Equation 11 or Equation 12 to calculate the rotational energy Eav of the rotor 1 at the moment of inertia Ip or the rotational speed Nav. In Step 723, Ip or Nav and Eav are converted into the RAM 208 of the nonvolatile memory. And the rotor energy Es at the allowable rotational speed Ns set by the operator by the user interface means 25 is calculated according to the following equation (13).

  In step 724, the inertia moment Ip or energy Eav of the rotor 1 measured by the CPU 201 and the CPU 211 is collated by communication, and it is determined whether the mutual CPUs have performed the inertia moment or energy calculation without any abnormality. If so, the values calculated by the CPUs are compared with each other, and if within a predetermined error, it is determined as normal and the process proceeds to step 726. If there is an error exceeding the predetermined value, it is determined that either one of the first control device 8 and the second control device 9 has a problem, and the process proceeds to step 725 to execute the deceleration stop processing of the motor 2. End measurement.

  Further, in step 726, the containment energy threshold value Ec lower than the containment energy of the centrifuge is compared with the rotor energy Es at the allowable rotational speed Ns at the set set rotational speed input from the user interface means 25. If it is equal to or greater than Ec, the process proceeds to step 725, where deceleration is stopped.

  The centrifuge according to the present embodiment is provided with the CPU 201 by inputting the rotor model (ID) code selected by the operator for centrifuging the sample by the user interface means 25, for example, the number assigned to each rotor. Can read the data of the specification of the selected rotor information from among a plurality of rotor tables stored in the RAM 208 of the nonvolatile memory. The first controller 8 determines the rotational speed Nu based on the rotor energy Eu at the predetermined rotational speed Nu stored as one of the rotor information of the selected rotor and the rotational energy Eav calculated in Step 723. Is compared with the energy Eu ′ estimated to be possessed by the rotor 1, and if there is an error exceeding a predetermined value, the rotor model code input from the user interface means 25 and the rotor being rotated are It is possible to decelerate and stop the motor 2 by judging that they do not match.

  In FIG. 10 showing the operation of the CPU 211, step 800 is a determination process for determining whether or not there is an acceleration start notification communication from the CPU 201 for synchronizing the CPU 201 and the CPU 211 with respect to the measurement of the rotational speed N2. Proceeding to step 801, if the rotational speed of the motor 2 is less than the moment of inertia or the lower limit rotational speed of energy calculation, the process returns to step 800. Conversely, if the rotational speed is equal to or higher than the upper limit rotational speed Nlim, an abnormality has occurred in the first control device 8. In step 802, the I / O 217 outputs a cutoff signal to the second cutoff device 21 via the signal line 23 so that the power input to the inverter converter 3 is cut off. End energy measurement.

  If it is determined in step 800 that an acceleration start notification has been communicated, the process proceeds to step 803 to measure the rotational speed N2. In step 804, the time interval is taken by the time interval ty, and the process proceeds to step 805, where it is determined whether the rotational speed N2 is measured and the acceleration is increased by the increased rotational speed ΔNx or more. If the increased rotational speed has not accelerated more than ΔNx, it waits until it increases by ΔNx. If the acceleration is greater than ΔNx, the process proceeds to step 806, where the rotational speed N3 and the time difference Δtf required for acceleration from N2 to N3 are measured. In step 807, the time difference between the motor current Iw and the smoothing capacitor voltage V2 is measured. The average value Iwav of the effective current of the current signal Iw at Δtf, the average value V2av of the voltage signal V2, and the average rotation speed Nav of the motor 2 between times T2 and T3 are obtained.

  Step 808 is processing for determining whether or not there is a deceleration start notification communication from the CPU 201 to synchronize the CPU 201 and CPU 211 with respect to the measurement of the rotational speed N4. If there is no communication, the process proceeds to step 809 and the speed is less than Nlim. For example, the process returns to step 808, and if it is Nlim or more, in step 810, a cutoff signal is output from the I / O 217 to the second cutoff device 21 via the signal line 23, and the energy measurement is terminated.

  If it is determined in step 808 that a deceleration start notification has been communicated, the process proceeds to step 811 where the rotational speed N4 is measured. In step 812, the rotational speed N4 is measured, and then it is determined whether the speed is reduced by ΔNy or more. If the rotational speed is not decelerating more than ΔNy, it waits until it decelerates more than ΔNy. If the vehicle is decelerated by ΔNy or more, the process proceeds to step 813, where the rotational speed N5 and the time tb required for deceleration from N4 to N5 are measured. Thereafter, in steps 814 and 815, processing similar to that in steps 719 and 723 in FIG. 9 is performed, and the rotational energy Em of the rotor 1 at the rotational speed Nm identified by the second control device 9 is obtained. In step 815, Ip Alternatively, Nm and Em are stored in the EEPROM 218 of the nonvolatile memory, and the calculation ends.

  The second control device 9 receives the communication signal from the SCI 209 of the first control device 8 and then considers the time delay to start the measurement, so that the time interval ty in step 804 is the step in FIG. It is assumed that the time is shorter than ty in 708, and ΔNx and ΔNy in steps 805 and 812 are smaller than ΔNx and ΔNy in steps 709 and 716 in FIG. By taking time alignment, it is possible to minimize the error in energy identified by the first control device 8 and the second control device 9. Further, in this embodiment, the measured rotor energy and the measured speed are stored in the nonvolatile memory 208 such as RAM and the nonvolatile memory 218 such as EEPROM, and a power failure occurs after the rotor energy measurement is completed and power is restored. Even when the speed of the rotor 1 is high, the rotor energy can be managed by reading Eav and Em from the nonvolatile memories 208 and 218.

  Next, the operation of shutting off the power supply to the motor 2 of the first control device 8 and the second control device 9 during the centrifuge operation will be described with reference to FIGS. FIGS. 11 and 12 are flowcharts showing the operations of the first control device 8 and the second control device 9, respectively.

  In FIG. 11, step 900 determines whether or not the rotor 1 is rotating. If not, the process proceeds to step 901, where the rotational speed Nav and rotational speed at the time of energy measurement stored in the RAM 208 of the nonvolatile memory are stored. The rotational energy Eav of the rotor 1 at Nav is cleared, and the process returns to Step 900. If it is determined in step 900 that the rotor 1 is rotating, the process proceeds to step 902, where it is determined whether the rotation speed N1 is exceeded and the measurement of Eav is completed. When the measurement is not completed, the process returns to Step 900, and when the measurement is completed, the rotor energy E at the current rotational speed N of the motor 2 is calculated according to the following equation at Step 903 based on Nav and Eav.

Step 904 determines the magnitude of the containment energy threshold Ec of the centrifuge and the rotor energy E at the rotational speed N. If E is equal to or greater than Ec, the process proceeds to Step 905 and outputs a cutoff signal to the first cutoff device 20. If E is less than Ec, the process proceeds to step 906. In step 906, the above-mentioned E is compared with the rotor-specific energy upper limit Emax at the allowable maximum rotational speed Nmax of the rotor selected by the operator via the user interface means 25. If E is equal to or greater than Emax, the process proceeds to step 905 to output a shut-off signal to the first shut-off device 20; if E is less than Emax, the process returns to step 900; The rotor is monitored against the centrifuge containment energy or the rotor specific energy upper limit Emax. As energy does not exceed, the monitoring of energy is performed.

  The operation of the second control device 9 is the same as the operation of the first control device 8 described with reference to FIG. 11, as shown in FIG. 12, and the rotor at the rotational speed Nm and the rotational speed Nm at the time of energy measurement. The clearing and reference of the rotational energy Eav of 1 is intended for the EEPROM 218, and the prohibition of driving the motor 2 is determined by determining the magnitude of the enclosing energy threshold value Ec of the centrifuge and the rotor energy E at the current rotational speed N. This is done by outputting a cut-off signal to the second cut-off device 21 when Ec or more is reached.

  Next, in the case where the set rotation speed and the limit rotation speed of the rotor 1 are performed not by the calculated rotation energy but by the inertia moment Ip, a database for determining the limit rotation speed threshold and the set rotation speed threshold is simulated by five types of rotors. This will be described with reference to FIG.

The energy limit value 602 (energy (kJ) axis) indicates the upper limit value of the containment energy of the centrifuge 100 according to the present embodiment, and the centrifuge 100 is guaranteed to withstand an energy of about 175 kJ. Is done. The limit rotation speed threshold 600 is an allowable rotation speed (min ⁻¹ ) of the rotor 1 alone. The set rotation speed threshold 601 is a set rotation speed threshold set by the user who operates the centrifuge 100, and a rotation speed lower than the limit rotation speed threshold 600 is set while ensuring a safety margin. For example, even if the inertia moment Ip is calculated including a maximum ± 10% error with respect to the true inertia moment of the rotor 1, the same limited rotational speed threshold value 600 and the set rotational speed threshold value 601 should be selected. The limit rotation speed threshold value 600 and the set rotation speed threshold value 601 are drawn in consideration of these calculation errors.

For example, when the calculated value of the inertia moment Ip of the rotor 1 is 3370 (× 10 ⁻⁴ kg · m ² ), the value 3370 on the horizontal axis of the database calculated inertia Ip (× 10 ⁻⁴ kg · m ² ) In this case, a limit rotational speed threshold value of 9000 min ⁻¹ is obtained from the intersection P (black ●) of the line 603 and the line 600 extending vertically from the point. Similarly, the intersection point Q (white square □) with the line 601 is the set rotational speed threshold value, and in this case, 8500 min ⁻¹ is obtained, and the point R (white square Δ) on the line 603 is the limit rotational speed threshold value of the rotor 1. Rotational energy during rotation is 150 kJ in this case. In this way, the line 600 is set to be less than 175 kJ, which is the containment energy limit value of the centrifuge 100 when the rotor 1 rotates at the speed limit, and the line 601 is set to a value smaller than the line 600. Is set. The point of intersection with the line 600 (Ipmax (outline □) and Ipmin (outline □) is the point P when there is no error in the calculated Ip, whereas the error is calculated at −10%. Is expressed as Ipmin, and when the error is calculated as + 10%, it is expressed as Ipmax.The set rotational speed corresponding to the calculated moment of inertia is compared with the set rotational speed input by the user, and the set rotational speed is limited. When the speed is exceeded, the rotation of the motor is stopped.

  The lines 600 and 601 are stepped, and are broken lines that become lower as the calculated moment of inertia Ip increases. This is because there is a large difference in the actual moment of inertia Ip when the tube and sample are almost light, even when the rotor is the same type, and when the sample is full and a metal tube is used. Is set to a position where an error is further added by + 10% at the moment of inertia of the rotor of the type.

  Since the inertial moment Ip to be calculated has a predetermined numerical range, the line 601a and the line 601b are guard lines for preventing the rotor 1 from rotating when the inertial moment is outside the predetermined range. Since the energy Emax when controlled by the rotational energy of the rotor 1 corresponds to the line 602 and the allowable maximum rotation Nmax of the rotor 1 corresponds to the line 600, the current rotational speed N and the calculated moment of inertia Ip are used. To calculate Er.

  By this replacement, control is performed according to the flowcharts of FIGS. 11 and 12, and the first control device 8 and the second control device 9 respectively compare this E with the containment energy threshold value Ec of the centrifuge, and E is Ec. Since it operates so as to output a shut-off signal to the first shut-off device 20 and the second shut-off device 21 when it is determined that the rotor has exceeded, the rotor 1 energy does not exceed the containment energy of the centrifuge 100. It is clear that a speed limit of 1 is possible.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. It is.

DESCRIPTION OF SYMBOLS 1 Rotor 2 Motor 3 Inverter converter 4 AC power supply 5 1st speed detection means 6 2nd speed detection means 7 Magnet 8 1st control apparatus 9 2nd control apparatus 10 Bowl 11 Protecting ring 12 Door 13 Torque transmitter 14 drive shaft 15 frame 16 first current detector 17 second current detector 18 first DC voltage detector 19 second DC voltage detector 20 first cutoff device 21 second cutoff device 22 signal line 23, 24 Communication line
25 User interface means 26 Third speed detecting means 27 Encoder disk 30 Signal lines 31, 32, 33 Inverter bridge 51 Rotor adapter 52 Magnet 53 Signal generator 54 Identification hole pattern 55 Eddy current sensor 56 Signal line 100 Centrifuge 201 CPU 202 Current RMS Converter 203 A / D Converter 204, 205 MTU 206 A / D Converter 207 I / O
208 Nonvolatile memory 209 SCI 210 Inverter control unit 211 CPU 212 Current effective value converter 213 A / D converter 214, 215 MTU 216 A / D converter 217 I / O
218 Nonvolatile memory 219 SCI
221, 230, 231 MTU 222 Signal converter 223 Non-volatile memory 301 Upper arm 302 Lower arm 304 Gate control circuit 305 Photocoupler 306 Gate control circuit 307 Photocoupler 308, 309 Resistor 310 Power supply 311 Smoothing capacitor 312 Converter 313 Relay contact 314 Relay coil 316, 317, 318 Driver 600 Limited rotation speed threshold value 601 Set rotation speed threshold value 602 Containment energy limit value 601a of centrifuge 100 Guard line 601b of set rotation speed threshold value and limited rotation speed threshold value when calculation Ip is small Guard line 1300 for the set rotation speed threshold value and limit rotation speed threshold value in the case of large rotor selection button 1301 start button 1302 confirmation button Iu current signal Iw current signal MPG, R PG, SPG pulse signal
ENCa, ENCb Two-phase pulse signal ID Rotor discrimination signal V1, V2 Voltage signal F Frequency of internal clock of CPU 201 or CPU 211 CNT Clock count between falling edges N Current speed of motor 2 τa Motor at acceleration Output torque τm of motor 2 Output torque of motor 2 during measurement N1 Rotational speed of motor 2 at time T1 Rotational speed of motor 2 at time T2 N3 Rotational speed of motor 2 at time T3 N4 Motor 2 at time T4 Rotational speed N5 Rotational speed Nav of motor 2 at time T5 Average rotational speed T1 of motor 2 between times T2 and T3 Time T2 at which rotational speed N1 during acceleration T2 Measurement start time at torque τm T3 Measurement at torque τm End time T4 Measurement start time with natural deceleration T5 Measurement end time with natural deceleration Nf From time T2 to T3 Rotational speed Nb of motor 2 in high speed state Rotational speed of motor 2 in natural deceleration state from time T4 to T5 Δtf Time difference Δtb Time difference tr One rotation period Δt of motor 2 Time delay relative to actual speed No Ideal rotational speed of motor 2 Nr Instantaneous current rotational speed of motor 2 Nn Current speed after filtering Nn-1 Previous speed after filtering α Filtering constant N Current rotational speed of motor 2 k Constant coefficient Ip Moment of inertia of rotor 1
Ir Moment of inertia Iuav of rotation system other than rotor 1 Average value V1av of effective current of current signal Iu Average value Iwav of voltage signal V1 Average value of effective current V2av of current signal Iw Average value t2 of voltage signal V2 From time T1 to time T2 Time interval ty Predetermined time interval tz in the acceleration state of torque τm Time interval of torque zero from time T3 to T4 ΔNx Increase rotational speed after measuring rotational speed N2 ΔNy After measuring rotational speed N4 Rotational speed Nlim Inertia moment of rotor 1 or upper limit speed Em of energy calculation Rotational energy Ns of rotor 1 at rotational speed Nm Permissible rotational speed Es Rotor energy E at permissible rotational speed Ns Rotor energy Ec at present rotational speed N Centrifuge containment energy threshold Er Rotor energy Nmax at the instantaneous current rotational speed Nr of the motor 2 Maximum allowable rotational speed Emax of the rotor At the maximum allowable rotational speed Nmax of the rotor, the upper limit energy P peculiar to the rotor P The intersection of the line 603 and the line 600 (black)
Intersection with Q line 601 (outlined □)
Point on R line 602 (open triangle)

Claims (16)

A rotor that holds the sample and is detachably mounted;
A motor for rotating the rotor;
An inverter converter for outputting a variable frequency AC voltage to the motor;
A rotating chamber that houses the rotor;
An ID detector for reading ID information attached to the rotor;
A speed detector for detecting the rotational speed of the rotor or the motor;
A centrifuge having a control device for controlling the operation of the centrifuge,
The controller is
Reading the ID information of the rotor;
If the ID information cannot be detected, calculate the moment of inertia of the rotor,
A limit rotational speed threshold is determined from the moment of inertia,
When the set centrifugal rotation speed is equal to or lower than the limit rotation speed threshold, the rotation of the rotor is accelerated to the set rotation speed and settling,
The centrifuge is characterized in that the rotation of the rotor is stopped when the set centrifugal rotation speed exceeds the limit rotation speed threshold. When the ID information can be detected, the control device determines the validity of the set rotational speed based on the detected information,
If it is reasonable to accelerate the rotation of the rotor to the set rotational speed, if not valid centrifuge according to claim 1, characterized in that stopping the rotation of the rotor.   The ID detector is a signal generator for detecting magnetism of a magnet arranged in the rotor, and / or a signal generator for detecting presence / absence of an identification hole provided in the rotor. Item 3. The centrifuge according to Item 2. A current detector for detecting the current of the motor;
A DC voltage detector for detecting a DC power supply voltage of the inverter converter is provided,
The controller is
Controlling the rotor to a predetermined torque,
The product of the detected current and the DC voltage detector by Ri detected DC power supply voltage by the current detector, divided by the rotational speed of the motor detected by the speed detector, determined this advance 4. The centrifugal separator according to claim 1, wherein a moment of inertia of the rotor is obtained by multiplying the torque constant. A storage means is provided in the control device,
The centrifugal separator according to claim 4, wherein the value of the torque constant is stored in advance in the storage means. The limiting rotational speed threshold calculated by the control device is set such that rotational energy when the rotor rotates at the limiting rotational speed is less than a containment energy limit value of the centrifuge. The centrifuge according to claim 5. The controller is
Accelerating the rotor from a first rotational speed to a second rotational speed;
And the average current of the motor by the current detector, the product of the DC voltage detector is by Ri detected in the DC power supply average voltage, divided by the average rotational speed of the front SL motor Ru good to the speed detector, before centrifuge according to claim 6, characterized in that to calculate the moment of inertia and calculated over the serial torque constant.   The said control apparatus controls the said inverter converter so that the output torque of the said motor may become a fixed value, The said rotor is accelerated from 1st rotation speed to 2nd rotation speed, It is characterized by the above-mentioned. 8. The centrifuge according to 7. The controller is
Upon reaching the second rotational speed the rotor is accelerated, the output torque of the motor by controlling the inverter transformer to be zero,
The rotor was decelerated from the second rotation speed to a third rotation speed, measuring the rotor or the rate of change of the rotational speed before Symbol decrease deceleration time by the speed detector at this time
Centrifuge according to claim 7 or 8, wherein the determination of the moment of inertia of the rotor based on an output torque correction value and the previous Kikai rolling rate of change of velocity of the motor. First and second current detector for detecting a current before SL motor,
First and second DC voltage detectors for detecting a DC power supply voltage of the inverter converter ,
Has first and second speed detectors as the speed detector,
The control device includes first and second control devices ,
The first control device calculates a product of an average current of the motor by the first current detector and a DC power source average voltage of the inverter converter by the first DC voltage detector as a rotational speed of the motor. The inertial moment of the rotor is obtained by multiplying a predetermined torque constant by dividing the rotational speed based on the average rotational speed of the rotor by the first speed detector for detecting
The second control device calculates a product of an average current of the motor by the second current detector and a DC power source average voltage of the inverter converter by the second DC voltage detector as a rotational speed of the motor. by multiplying the average predetermined torque constant divided by the rotational speed based on the rotational speed of the rotor by the second speed detector for detecting and obtaining the moment of inertia of the rotor according to claim 1 The centrifuge described in 1 . The first control device includes:
Comprising user interface means by which an operator can arbitrarily set the set rotational speed of the rotor,
From the calculated moment of inertia of the rotor, a limiting rotational speed threshold value equal to or lower than the containment energy of the centrifuge of the rotor and a set rotational speed threshold value lower than the limiting rotational speed threshold value are obtained,
Shutting off the voltage supply to the motor from the inverter converter by outputting a cutoff operation signal to the inverter converter when it is determined that the limit rotational speed threshold has been exceeded,
When it is determined that the rotational speed of the rotor is set to exceed a set rotational speed threshold, the rotational speed of the rotor is controlled to be equal to or less than the set rotational speed threshold;
The second control device includes:
From the calculated moment of inertia of the rotor, a limit rotational speed threshold value equal to or less than the containment energy of the rotor centrifuge is obtained, and when it is determined that the limit rotational speed threshold value is exceeded, a shutoff operation signal is output to the inverter converter, The centrifuge according to claim 10, wherein voltage supply to the motor from an inverter converter is cut off. The centrifuge includes a first shut-off device and a second shut-off device that shut off the voltage supply to the motor from the inverter converter that is arranged independently of the voltage feed path from the inverter converter to the motor. With
The first control device outputs a cut-off operation signal to the first cut-off device when it is determined that the limit rotation speed threshold is exceeded in a state where the rotor is rotating at an arbitrary rotation speed, and the inverter converter Shut off the voltage supply to the motor from
The second control device outputs a shut-off operation signal to the second shut-off device when it is determined that the limit rotational speed threshold has been exceeded in a state where the rotor is rotating at an arbitrary rotational speed, and the inverter converter The centrifuge according to claim 10, wherein voltage supply to the motor is cut off. A communication means is provided between the first control device and the second control device,
The said 1st control apparatus controls the said inverter converter, and synchronizes the time regarding the measurement of the inertia moment of the said rotor with the said 2nd control apparatus via the said communication means. The centrifuge according to 12 .   The centrifuge according to claim 13, wherein the first control device decelerates the motor when it is determined that communication with the second control device is abnormal.   The said 2nd control apparatus outputs a interruption | blocking operation signal to a said 2nd interruption | blocking apparatus, when it determines that communication with the said 1st control apparatus by the said communication means is abnormal. The centrifuge described in 1.   When the first controller determines that an error between the rotor inertia moment calculated by the first controller and the rotor inertia moment calculated by the second controller exceeds a predetermined value, The centrifuge according to claim 13, wherein the motor is decelerated by controlling an inverter converter.

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