JPH08299851A - Centrifugal separator - Google Patents

Abstract

PURPOSE: To secure safety and to recover specimens in a shortest time in a control method in which the detection of speed becomes impossible in the operation of a centrifugal separator so that the rotation has to be stopped. CONSTITUTION: A rotor 1 is rotated by a driving unit 2, the speed is detected by a speed detection sensor 3 and a speed detection device 4, and the kind of the rotor is detected by a rotor identification sensor 5 and a rotor identification device 6. A controller 7 is equipped with a clock circuit 8 provided with an auxiliary battery 9 for use in power failure and controls the operation of the driving unit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to operation control when a speed cannot be detected or a power failure occurs during operation of a centrifuge.

[0002]

2. Description of the Related Art In a centrifuge, in order to control the rotation speed to a normal set speed with high accuracy, feedback control is performed by detecting the rotation speed of a rotating body or a driving device for rotating the rotating body. During operation, if it cannot be detected by the speed detection device that detects the speed of the rotating body or the drive device, it may rotate beyond the set speed. Also, even if the rotating body or the drive device is rotating, the speed cannot be detected, so it is determined that the rotation is stopped, the mechanism that interlocks the door of the rotating body chamber is released, and the worker is set to the rotating rotating body. There is a problem that your hands will touch. As a first preventive measure, it is conceivable to provide an overspeed detecting device that decelerates and stops when the speed exceeds the permissible speed of the rotating body or the driving device, in addition to the speed detecting device.
Secondly, it is considered that the centrifuge is equipped with a safety mechanism such as unconditionally decelerating and stopping when the speed of the rotating body or the driving device cannot be detected. In the centrifuge which cannot be equipped with both the speed detection device and the overspeed detection device structurally or costly, the second method is adopted and stopped by brake or natural deceleration (without brake). In a conventional centrifuge, if the speed detection device cannot detect the speed of the rotor or drive during rotation, the speed is unconditionally decelerated and stopped, but the time until the rotor or drive completely stops In order to prevent reacceleration, or to prevent the door interlock from being unlocked in the rotating room, do not operate the start switch or reacceleration device within the specified time as speed undetectable processing or interlock. I try not to release it. When exchanging multiple rotating bodies, use the rotating body that has the largest moment of inertia and the longest deceleration time for invalidating the re-accelerating means and interlock releasing means It was set to a value exceeding the time from the rotation speed (usually the maximum rotation speed of the rotating body for safety reasons) to stopping. Furthermore, during operation, if a power failure occurs when speed detection cannot be performed and speed detection impossible processing is being performed, conventionally the power failure time cannot be measured from the power failure until power is resumed, so the power failure time is subtracted from the control invalid time. I couldn't.

[0003]

In the conventional centrifuge, when the speed cannot be detected during rotation of a rotating body having a small moment of inertia, the time required for the rotating body having a large moment of inertia to stop from the number of rotations used. In the control invalid time set in consideration of the above, even if the rotation is already stopped, the door interlock of the rotor chamber was released, and the rotor could not be taken out and the sample could not be collected. Especially in the type in which the inside of the rotating body is decompressed and used for rotation by the high-frequency induction motor in an ultracentrifuge, if the speed of the rotating body cannot be detected, natural deceleration is performed to protect the motor drive circuit from damage. Although it will be stopped by, the time until it stops will differ by several hours due to the difference in the moment of inertia. If a power failure occurs within the control invalid time, or if the user intentionally turns off the power of the centrifuge, the power failure time cannot be measured and the control invalid time remains as it is. Even if it was stopped, there was a problem that the door interlock could not be released and the sample could not be collected.

An object of the present invention is to ensure the safety and to collect the sample in the rotating body in the shortest possible time when the speed of the rotating body or the driving device cannot be detected during the operation and the operation must be stopped. It is to be.

[0005]

The above object is to identify the rotating body being used, set the control invalid time to a time commensurate with the rotating body, and measure the time even during a power failure. The power failure time after power transmission is also achieved by adding a function to add to the control invalid time.

[0006]

[Function] The function configured as described above is the time obtained by subtracting the power outage time from the control ineffective time after the control ineffective time corresponding to the magnitude of the inertia moment of the rotating body has elapsed or after the power is restored. After a lapse of time, the door interlock operates so as to be released.

[0007]

EXAMPLES The present invention will be described below with reference to examples. FIG.
At 1, the rotating body 1 containing the sample is rotated at high speed by the driving device 2. The control device 7 detects the rotation speed of the rotating body 1 by the speed detection sensor 3 and the speed detection device 4,
The driving device 2 is controlled by taking in the speed information. Further, the control device 7 identifies the type of the rotator 1 by the rotator identification sensor 5 and the rotator identification device 6, and controls the drive device 2 to match the rotator 1. The control device 7 is connected with a clock circuit 8 that manages the operating time and the time of various devices inside the centrifuge, and a power source is supplied by an auxiliary battery 9 so that the function of the clock circuit is maintained even in the event of a power failure. Have been backed up.

The control operation will be described below with reference to the flow charts shown in FIGS. In FIG. 2, the type of the rotating body 1 is identified by the rotating body identifying sensor 5 and the rotating body identifying device 6 when the operation is started. If the speed cannot be detected during the rotation, the control device 7 sets the control invalid time Td corresponding to the identified rotating body to decelerate the rotating body. It should be noted that Td is a time that allows a certain amount of time for the identified rotating body to stop rotating due to natural deceleration (in some cases, applying a brake) from the used rotation speed (for example, the maximum rotation speed). When the control invalid time is set, the reacceleration command and the door interlock release command are invalidated, and Td is subtracted according to the elapsed time. The subtraction is continued until Td becomes zero, and when it becomes zero, the reacceleration command and the door interlock release command are validated. At this point the rotor is stopped and the door can be opened. Re-acceleration is possible without speed detection, but since the control device 7 cannot detect speed even if an acceleration command is issued, it is possible to detect speed detection failure in the low-speed range, and again control invalid time Td '(in this case, Td is set in consideration of the time taken for the rotating body used to decelerate from the low speed range and stop), and the same control is performed thereafter.

FIG. 3 is a flow chart in the case where a power failure occurs while the speed cannot be detected during rotation (or when the user intentionally turns off the power of the centrifuge), and the clock backed up by the auxiliary battery during the power failure. The circuit is working.
At the time of resuming energization, the control device 7 calculates the power failure time Tt, and further subtracts Tt from the control invalid time Td that has already passed. After that, the processing when the speed cannot be detected is continued according to the flowchart of FIG.

The invalidation of the reacceleration command and the door interlock command is described as the processing when the speed cannot be detected, but an alarm is issued to the user to the effect that the speed cannot be detected (for example, a voice alert or a liquid crystal screen or light emission) is issued. It is common in a centrifuge that a function such as (displayed by a diode or the like) is attached.

[0011]

According to the present invention, when the speed of the rotating body or the driving device cannot be detected during operation and the operation must be stopped and the sample must be collected, the door is decelerated / stopped according to the type of the rotating body. The time until the lock is released is set and controlled, ensuring safety and reliability,
Moreover, the sample in the rotating body can be collected in the shortest possible time. In addition, since the power failure time can be measured and the power failure time can be recognized as the time during deceleration, the same effect can be obtained.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of a centrifuge according to the present invention.

FIG. 2 is a flowchart showing control of the centrifuge according to the present invention.

FIG. 3 is a flowchart showing control of the centrifuge according to the present invention.

[Explanation of symbols]

1 is a rotary body, 2 is a drive device, 3 is a speed detection sensor, 4 is a speed detection device, 5 is a rotary body identification sensor, 6 is a rotary body identification device, 7 is a control device, 8 is a clock circuit, 9 is auxiliary It is a battery.

Claims (3)

[Claims] 1. A rotating body containing a sample, a driving device for driving the rotating body, a control device for controlling the driving device, and a speed of the rotating body or the driving device. In a centrifuge having a speed detecting device and a rotating body identifying device capable of discriminating the type of the rotating body, the rotating body is rotated while the rotating body or the driving device is rotating after the type of the rotating body is discriminated. Alternatively, when the speed of the drive device cannot be detected, a centrifuge is provided with a function of performing processing when the speed cannot be detected according to the type of the rotating body. 2. A centrifuge having a timepiece function capable of measuring time, wherein the speed of the rotating body or the driving device cannot be detected while the rotating body or the driving device is rotating, If a power failure occurs while the control circuit is performing processing when the speed cannot be detected, the clock function measures the time with the power supply from the auxiliary battery during the power failure and calculates the power failure time when the power is resumed. A centrifuge characterized in that the control circuit is provided with a function of performing a process when speed cannot be detected after power recovery in consideration of time. 3. A plurality of the rotating bodies are exchanged for use,
In a centrifuge having the rotating body identifying device capable of discriminating the type of the rotating body, after the type of the rotating body is discriminated, a power failure occurs and after power restoration, speed detection is not possible depending on the type of the rotating body. The centrifuge according to claim 2, wherein the centrifuge is provided with a function of performing time treatment.