JP2001246292A - Centrifugal separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save labor in set operating steps during starting, in a centrifugal separator in which a maximum number of revolution and time for acceleration per rotor, and the like, are regulated. SOLUTION: In this centrifugal separator of such a type that magnets whose numbers meets the specifications of each of rotors are mounted on each of the rotors and the magnets are counted to read the specifications of each of the rotors, a magnetic sensor to be fitted to a stationary part is mounted each at a position corresponding to both ends of a range of an angle at which the magnet is fitted, and when two magnetic sensors detect the presence of the magnets simultaneously, the magnets fitted to each of the rotors are counted without receiving any influence by the rotary velocity of the rotor, by using the simultaneous detection as a signal which starts or a signal which ends the counting of the magnets. Thus, the data table of the rotors is read according to the count value. In addiction, the rotary velocity of the rotors is counted by diverting a signal generated upon a response with the magnetic sensor as a rotary detection signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal separator used for separating various kinds of samples for each component, and in particular, discriminates a type of a mounted rotor and drives the rotor to rotate by a control method suitable for the rotor. It has functions,
The present invention proposes a centrifugal separator having a function of detecting the rotation speed of the rotor using the function of discriminating the type of the rotor.

[0002]

2. Description of the Related Art A centrifuge is a device for rotating various kinds of rotors on which samples to be centrifuged are mounted at a high speed. Do us. As a method of controlling the centrifugal separator, if the type of rotor changes, control must be performed in accordance with driving conditions such as the maximum rotation speed, acceleration characteristics, and deceleration characteristics allowed for the rotor.

For example, when a high-frequency induction motor is controlled by an inverter, unless an acceleration characteristic and a deceleration characteristic are set in accordance with the magnitude of the moment of inertia of the rotor as a load, an overcurrent flows and a failure of the inverter or the motor may occur. There is a connection failure. If the rotor has an excessive imbalance, it is necessary to stop the operation to prevent danger. As described above, since various settings are required to start the centrifuge, there is a disadvantage that the handling becomes complicated. In particular, when many samples must be analyzed one after another, a troublesome operation is required, and the analysis operation takes a long time.

[0004] For this reason, the present applicant has disclosed in Japanese Patent Laid-Open No. 6-1982.
No. 19 (Patent No. 2514554) proposed a centrifuge in which these setting operations were automated. In the centrifuge proposed above, the specifications of each rotor are stored in advance in storage means such as a ROM or a RAM, and a plurality of magnets representing the specifications of each rotor are mounted on each rotor, and the number and arrangement of the magnets are set. By reading the pattern with the magnetic sensor provided on the fixed part, the storage means is accessed according to the number and arrangement pattern of the read magnets, data indicating the specifications of each rotor is read, and the read data is sent to the activation controller. By setting, various settings at the time of starting the centrifuge are automatically performed.

[0005]

According to the above-mentioned prior art, the specifications of the rotor are determined even when the rotor is stationary by simply mounting the rotor on the centrifuge, and various settings required at the time of startup are automatically set. Since the operation is started immediately after the operation is performed, there is an advantage that the analysis operation can be completed in a short time. However, since the number of magnets can be counted even when the rotor is stationary, there is a disadvantage that the number of magnetic sensors mounted on the centrifuge increases and the cost increases.

In the conventional centrifugal separator, since the rotation speed (rotation speed) of the rotor is detected by a rotation detector using an optical sensor, the rotation detector also has a disadvantage that the cost is increased. A first object of the present invention is to provide a centrifugal separator that can be manufactured at a low cost by reducing the number of magnetic sensors and that can be started in a short time.

A second object of the present invention is to use a function of judging the kind of the rotor and to divert it to a sensor for detecting the rotational speed of the rotor, thereby achieving a further reduction in cost. Is to offer a machine.

[0008]

According to the first aspect of the present invention, a rotor having various specifications is detachably mounted on a rotary drive shaft, and the rotary shaft drive characteristics are controlled in accordance with the specifications of the rotor. In a centrifugal separator, a plurality of magnets representing the specifications of each rotor are mounted on a rotor along a circumference having a rotation drive shaft as an axis, and a mounting angle range of the magnets on a fixed portion facing a mounting surface of the magnet. We propose a centrifuge with a structure in which magnetic sensors are mounted at positions corresponding to both ends of the centrifuge.

According to a second aspect of the present invention, in the centrifuge according to the first aspect, the magnetic sensors mounted at the positions corresponding to both ends of the mounting angle range simultaneously detect the presence of the magnet when the rotor rotates. The present invention proposes a centrifugal separator having a structure in which a signal is used as a counting start signal and a counting end signal of a magnet. According to a third aspect of the present invention, there is provided a centrifuge according to any one of the first and second aspects, wherein the angle range of the magnet mounted on the rotor is 180 °.

According to claim 4 of the present invention, claims 1 to 3
In any of the centrifuges described above, a centrifuge having a rotor abnormality determination means for determining that the rotor is not properly mounted on the drive shaft when the detection signal of the magnet does not reach the predetermined number of reactions. Suggest. According to a fifth aspect of the present invention, there is provided a centrifuge according to any one of the first to third aspects, wherein the magnetic sensor measures the number of rotations of the rotor based on a signal that simultaneously detects the presence of a magnet. .

According to claim 6 of the present invention, claims 1 to 3
A configuration in which the magnetic sensor detects the presence of a magnet in any of the centrifuges described, but at the same time does not detect the presence of a magnet, determines that the rotor is a predetermined specific rotor, and drives at a predetermined rotation speed We propose a new centrifuge.

[0012]

According to the structure of the centrifuge according to the present invention, a plurality of magnets indicating the specifications of each rotor are mounted on the rotor, but only two magnetic sensors may be mounted on the fixed part. As a result, the number of magnetic sensors is reduced to a fraction of that in the case of the centrifuge proposed above, and accordingly, the size of a circuit for capturing the detection signals of the magnetic sensors can be reduced, so that cost reduction can be expected. .

Further, as proposed in claim 3, when the mounting angle range of the magnet is set to 180 °, a signal for starting the counting of the number of magnets and a signal for ending the counting during at least one rotation of the rotor. Can be obtained. As a result, it is possible to determine the type of the rotor in a short time after mounting the rotor and complete the setting of the rotation speed. According to the centrifugal separator proposed in claim 5 of the present invention, the rotation speed of the rotor is detected by using the magnet and the magnetic sensor for determining the type of the rotor, so that the rotation detector for detecting the rotation speed of the rotor is provided. Need not be provided separately. Therefore, the advantage that cost reduction can be expected also in this point is obtained.

Further, according to the sixth aspect of the present invention, even when the presence of a magnet is not simultaneously detected in the two magnetic sensors H1 and H2, there is obtained an advantage that a function of discriminating the type of rotor can be provided. .

[0015]

FIG. 1 shows the structure of a main part of a centrifuge according to the present invention. 1 is a rotor chamber, 2 is a rotating shaft protruding from the axial position of the rotor chamber 1, 3 is a motor for rotating the rotating shaft 2, 4 is a rotor mounted on the rotating shaft 3, Reference numeral 5 denotes a fixing portion. In the present invention, a magnet and a magnetic sensor are mounted on the rotor 4 and the fixed part 5. That is, the magnet M is attached to the rotor 4, and the magnetic sensor H is attached to the fixed part 5.

The rotor 4 is generally conical, and has a magnet M mounted on the bottom surface thereof. As for the method of mounting the magnet M, FIG.
As shown in FIG. 3, a maximum of seven (M1 to M
Seven types of arrangement patterns can be obtained by adding six types of combinations from 7) to two of M1 and M7 and a combination of other magnets except one of M1 and M7 as a modification. . In the example shown in FIG. 2, an angle range of 180 ° is divided into 30 °, and magnets M1 to M
7 is shown. In the example shown in FIG.
A case where six magnets except for the magnet M4 at the center position in the angular pitch are arranged is shown. FIG. 4 shows an example of an arrangement pattern of the magnets M. When there are many types of rotors to be determined, the arrangement pitch of the magnets should be smaller than 30 °, for example, 20 °.
゜ It should be taken at the corner.

As the specifications of the rotor, the maximum rotation speed, the rotation radius, the centrifugal force, the acceleration characteristics, the deceleration characteristics, the imbalance sensitivity, the overspeed rotation speed, and the like can be considered. A method for counting the number of magnets M will be described. When the magnets M are arranged in an angle range of 180 °, the magnetic sensors H1 and H2 are arranged at both ends of the angle range in which the magnets M are arranged in the fixed portion 5 so as to face the circumference on which the magnets M are arranged. That is, the magnetic sensors H1 and H2 are arranged at 180 ° as shown in FIGS.

In the state shown in FIG. 2, the magnetic sensors H1 and H2
Simultaneously detect the presence of magnets M1 and M7. By utilizing this detection state as a count start signal, the magnetic sensor H1 detects the passage of the magnets M2, M3, M4, M5, M6 while the rotor 4 makes a half turn clockwise from that state. By counting the detection signal of the magnetic sensor H1, the presence of the five magnets M2 to M6 can be detected. When the magnet M6 passes through the magnetic sensor H1 and reaches the position where the magnet M7 faces the magnetic sensor H1, the magnet M1 faces the magnetic sensor H2 at this time. Therefore, the magnets M1 and M7 are in a state of facing the magnetic sensors H1 and H2 at the same time. In this state, the end of counting of the magnet M and the start of counting are commanded, and the second counting is started. When the first count value and the second count value match, it is determined that the number of magnets M has been correctly counted, and the type of the rotor 4 can be determined according to the value of the magnet M.

As described above, the magnetic sensors H1 and H2 are arranged at both ends of the magnet mounting angle range, and when the magnet mounting angle range is set to 180 °, the magnetic sensor H1 is rotated during one rotation of the rotor 4. H1 and H2 always have two chances to detect the presence of the magnet at the same time. Also, when the magnet mounting angle range is arranged at an angle smaller than 180 ° and the magnetic sensors H1 and H2 are arranged at both ends of the mounting angle range, the magnetic sensors H1 and H2 must be at least during one rotation of the rotor 4. One time is given the opportunity to simultaneously detect the presence of the magnet.

Accordingly, the rotation speed of the rotor 4 can be reduced by utilizing the signals obtained by the magnetic sensors H1 and H2 simultaneously detecting the presence of the magnet without providing any means for detecting that the rotation shaft 2 has made one rotation. Is unknown, the number of magnets attached to the rotor 4 can be accurately counted. Further, in the present invention, the magnetic sensors H1 and H1
Focusing on the fact that the signal for detecting the presence of the magnet 2 at the same time is obtained each time the rotor 4 makes a half turn or one turn, it is also claimed that this signal is used as a detection signal of the rotation speed of the rotor 4. It is.

That is, the mounting angle range of the magnet is 180
In the case of ゜, as described above, the magnetic sensors H1 and H2 are given two chances to simultaneously detect the presence of the magnet during one rotation of the rotor 4, so that, for example, the number of signals detected in one second Is N, the rotation speed of the rotor 4 per minute can be obtained by (N / 2) × 60 rpm. If the magnet mounting angle range is smaller than 180 °,
It is determined at N × 60 rpm.

Therefore, the rotation speed of the rotor 4 can be detected without mounting the rotation detecting means on the rotation shaft 2, and the detection of the maximum rotation speed determined for each type of the rotor 4 and the maximum rotation speed Can be used as a control signal for maintaining FIG. 5 shows a block diagram of the electric system of the centrifuge according to the present invention. Reference numeral 10 denotes a microcomputer. As is well known, the microcomputer 10 includes a central processing unit 11, a ROM 12, a RAM 13, an input port 14, an output port 15, and the like.

The ROM 12 has a start program 12B for starting the centrifuges in a predetermined order, a collation program 12
C or a program constituting the rotor abnormality determination means 12D is stored, and a rotor-specific data table 12A for each type of rotor 4 shown in FIG. 4 is stored. The input ports 14 are connected to magnetic sensors H1 and H2, as well as a temperature sensor 17, a vibration sensor 18, an operation panel 19 and the like.

The output port 15 has a motor 3 and a refrigerator 2
0 and the rotation speed indicator 21 are connected, and the motor 3 and the refrigerator 20
Is started and stopped. The operation panel 19 is provided with a start switch. By operating the start switch with the rotor 4 mounted, the microcomputer 10 starts executing the start program 12B.

When the execution of the startup program 12B is started, the motor 3 starts rotating. When the rotation of the motor 3 is started, the microcomputer 10 immediately starts the magnetic sensors H1 and H even if the rotation speed is not stable at a constant rotation speed.
The program branches to a program for counting the number of magnets M by 2.
In the program for counting the number of magnets M, the number of magnets passing through one of the magnetic sensors H1 and H2 is counted from the state where the magnetic sensors H1 and H2 simultaneously detect the magnetic field.
This counting is performed by a counter 13A configured using a partial area of the RAM 13. The first count value and the second count value are obtained by the counter 13A.

When the second count value is obtained, the collation program 12C stored in the ROM 12 is started, and the first count value and the second count value are collated. When a match is detected as a result of the comparison, the data of the rotor corresponding to the matched numerical value is read from the rotor-specific data table 12A,
3 in each setting unit. The microcomputer 10 controls the rate of increase (acceleration characteristic) of the rotation speed of the motor 3 according to, for example, the acceleration characteristic according to each data of the rotor 4 set in the RAM 13.

The rotation speed measuring means 13B is provided with a magnetic sensor H1.
And H2 simultaneously count the number of times that the presence of the magnet is detected, for example, every second, determine the number of revolutions per minute, for example, according to the count value, and supply the value to the rotation speed indicator 21 from the output port 15; Displays the rotation speed per minute. At the same time, the current rotation speed of the rotor 4 is input to the motor control program provided in the start-up program 12B, and a difference from the maximum rotation speed read from the rotor-specific data table 12A is obtained. The drive circuit of the motor 3 is controlled so as to converge. With this control, the rotation speed of the motor 3, that is, the rotation speed of the rotor 4 is determined by the data table 1 for each rotor.
The maximum speed read from 2A is maintained.

According to a fourth aspect of the present invention, if the rotation is started while the rotor 4 is not properly mounted on the rotary shaft 2, this state is detected and the motor 3 is provided with a function for stopping the motor 3. We propose a separator. For this reason, according to the present invention, although the motor 3 is activated, the magnetic sensors H1 and H2 detect that the magnets are not detected at all, and it is determined that the rotor 4 is not properly mounted. A determination unit 12D is provided. In this embodiment, the rotor abnormality judging means 12D is a read-only memory 1
2 shows a case where the program is configured by the program stored in the second program.

When the rotor 4 is mounted in a floating state, the distance between the magnets and the magnetic sensors H1 and H2 increases, so that even when the rotor 4 rotates, the magnetic sensors H1 and H2 detect the presence of the magnets. Can not. If this state continues for a certain period of time, the rotor abnormality determination means 12D
Is not properly mounted, and the driving of the motor 3 is stopped. FIGS. 6 to 8 are flowcharts showing the outline of the control program. In steps S2 to S4 shown in FIG. 6, the first counting of the magnets M is performed. In step S5, the first counting of the magnets M ends.

In steps S6 to S8, the second counting of the magnets M is executed, and in step S9, the first and second counting results are compared. If the collation results match, it is determined in step S10 shown in FIG. 7 whether predetermined rotor characteristics are registered in the rotor-specific data table 12A. If the data is registered, the data is read from the ROM in step S11, the rotation speed is increased in step S12 by an acceleration according to the characteristics of the rotor in accordance with the data, and the number of simultaneous reactions of the magnetic sensors H1 and H2 is determined in step S13. The counting is performed, the rotation speed of the rotor 4 is measured, and the maximum speed specified by the characteristics of the rotor 4 is maintained in step S14.

In the collation operation in step S9, if a mismatch is detected, the flow returns to step S2, and the counting of magnets is executed again. Note that a counter C may be provided in the routine that returns to step S2, and the counter C may be forcibly stopped when the counter C counts, for example, "3". If the predetermined rotor characteristics do not exist in the data table 12A of the ROM 12 in step 10, the process branches to step S15. In step S15, it is determined that there is a possibility that the magnet of the rotor has fallen off, a warning is displayed in step S16, and the rotation of the motor 3 is stopped in step S17.

If the two magnetic sensors H1 and H2 do not react at the same time in step S2 shown in FIG. 6, the process branches to step S18 shown in FIG. In step S18, the lapse of time from the start of rotation is counted. Until the fixed time elapses, the process returns to step S2 (FIG. 6). At the time when a certain time has elapsed, it is determined in step S19 whether or not any of the magnetic sensors H1 and H2 has a magnet reaction. If the magnetic sensors H1 and H2 have reacted, the process proceeds to step S20.

In step S20, it is determined that the rotor does not have the magnet at the position where the magnets react simultaneously, and in step S21
The characteristics of a rotor having no magnet that reacts simultaneously (corresponding to the rotor with the rotor name G shown in FIG. 4) are obtained from the ROM, and the motor is passed through the power limiting means for limiting the current or voltage supplied to the motor 3 in step S22. 3 is driven.
By driving the motor 3 via the power limiting means,
The motor 3 is driven at the slowest speed in the data table 12A, for example, 5000 rpm (estimated value).

If there is no response from the magnetic sensor according to the rotation speed in step S19, the flow branches to step S23. In step S23, it is determined that there is no rotor or the rotor is incorrectly mounted, a warning to that effect is displayed in step S24, and the rotation is stopped in step S25. By setting the arrangement angle range of the magnet M to 180 ° as in the above-described embodiment, two counts can be performed during one rotation of the rotor 4. Therefore, the number of magnets M can be counted within a time as short as possible, and the advantage that the type of the rotor 4 can be determined in a short time is obtained.

However, if there is enough time until the type of the rotor 4 is determined (when high speed is not required for the rise of the centrifuge), it is not always necessary to select 180 °, and it is not necessary to select 180 °. Any angle can be selected as long as the angle is within the above range. In this case, two counts can be executed without fail during two rotations of the rotor. The temperature sensor 17 shown in FIG. 5 is a temperature sensor that measures the internal temperature of the rotor chamber 1. When the temperature sensor 17 measures a temperature equal to or higher than a predetermined temperature, the refrigerator 20 is operated, and the temperature of the rotor chamber 1 is increased. An operation of lowering the internal temperature of the rotor chamber 1 is performed by flowing a refrigerant through a pipe (not particularly shown) wound around the outer periphery.

The vibration sensor 18 is attached to, for example, the motor 3, detects the vibration of the motor, and the amplitude of the vibration reaches the amplitude specified by the imbalance sensitivity in each rotor-specific data table 12 A stored in the ROM 12. If so, a warning is displayed or control such as lowering the rotation speed of the motor 3 is performed.

[0037]

As described above, according to the present invention, two magnetic sensors H1 and H2 are arranged opposite to both ends of the mounting angle range of the magnet M, and these two magnetic sensors H1 and H2 are arranged. Defines the start and end of the counting of the magnets M by using the signal of detecting the presence of the magnet M at the same time.
There is an advantage that the number of magnets M can be correctly counted without being affected by the rotation speed. At the same time, by using the signal for detecting the presence of the magnet,
Can be measured. As a result, the means for discriminating the model of the rotor 4 can be applied to the detection of the rotation speed of the rotor 4, so that there is no need to provide a rotation sensor using a conventionally used optical switch. Further cost reduction can be expected.

Further, since only two magnetic sensors are required, the number of magnetic sensors can be reduced. As a result, there is also obtained an advantage that the cost can be significantly reduced. Further, in the present invention, the positions of the magnetic sensors H1 and H2 are set to 180
By selecting ゜, the number of magnets M can be counted twice while the rotor 4 rotates once, so that the model of the rotor 4 can be determined in a short time. As a result, there is obtained an advantage that it is possible to provide a so-called fast-starting centrifuge in which processing such as rotor specification discrimination at the time of startup is fast.

Further, according to the present invention, when the rotor 4 is not properly mounted, the motor 3 is stopped, so that the rotor 4 may rotate at a high speed in a state where the rotor 4 is not properly mounted, causing a serious accident. Therefore, there is obtained an advantage that a highly safe centrifugal separator can be provided.

[Brief description of the drawings]

FIG. 1 is a side view for explaining an embodiment of the present invention.

FIG. 2 is a plan view for explaining a configuration of a main part of the present invention and its operation and effect.

FIG. 3 is a plan view similar to FIG. 2;

FIG. 4 is a diagram showing an example of specifications of a centrifuge.

FIG. 5 is a block diagram for explaining an embodiment of an electric system of the centrifuge according to the present invention.

FIG. 6 is a flowchart for explaining an outline of a startup program executed when the centrifuge according to the present invention is started.

FIG. 7 is a flowchart similar to FIG. 6;

FIG. 8 is a flowchart similar to FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor room 2 Rotating shaft 3 Motor 4 Rotor 5 Fixed part M, M1-M7 Magnet H, H1, H2 Magnetic sensor 10 Microcomputer 11 Central processing unit 12 ROM 12A Data table for each rotor 12B Start program 12C Verification program 12D Rotor abnormality Judging means 13 RAM 13A Counter 13B Rotational speed measuring means 14 Input port 15 Output port 17 Temperature sensor 18 Vibration sensor 19 Operation panel 20 Refrigerator 21 Rotational speed display

Claims (6)

[Claims] 1. A centrifugal separator in which rotors having various specifications different from each other are detachably mounted on a rotary drive shaft, and the rotary drive characteristics of the rotary shaft are controlled in accordance with the specifications of the rotor. A plurality of magnets representing the specifications of each rotor are mounted along a circumference having the rotation drive shaft as an axis, and a fixed portion facing the mounting surface of the magnet is provided at a position corresponding to both ends of the mounting angle range of the magnet. A centrifuge comprising a magnetic sensor mounted on each of them. 2. The centrifuge according to claim 1, wherein the magnetic sensors mounted at the positions corresponding to both ends of the mounting angle range start counting the magnets by detecting the presence of the magnets simultaneously by the rotation of the rotor. A centrifuge used as a signal and a count end signal 3. The centrifugal separator according to claim 1, wherein a mounting angle range of the magnet mounted on the rotor is 180 °. 4. The centrifuge according to claim 1, wherein the rotor is not properly mounted on the drive shaft when the detection signal of the magnet does not reach a predetermined number of reactions. A centrifugal separator characterized in that it is provided with a rotor abnormality judging means. 5. A centrifugal separator according to claim 1, wherein said magnetic sensor measures the number of rotations of said rotor by a signal which simultaneously detects the presence of a magnet. Separator. 6. The centrifuge according to claim 1, wherein the magnetic sensor detects the presence of a magnet.
At the same time, if the presence of a magnet is not detected, the centrifuge is determined to be a predetermined specific rotor and driven at a predetermined rotation speed.