JP2596600B2 - Centrifuge - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a safety device for a device such as a centrifuge that rotates a rotating container at a high speed.

[Background of the Invention]

A rotating container used in a centrifuge rotates at a high speed and therefore has a large rotational energy. An allowable rotation speed is determined to prevent breakage due to a centrifugal load. In addition, when the rotational speed is set or operated beyond the permissible rotational speed, a device for detecting and stopping the rotational speed is incorporated in the centrifuge.

However, in a centrifuge having a function of storing two or more types of operating conditions and automatically performing operations under the second and third conditions upon completion of the operation under the first condition, as shown in FIG. Unless the operating condition is satisfied under each condition, it cannot be determined whether or not the condition is equal to or more than the allowable value. That is, when the third condition is set, the operation under the second condition is terminated if the second condition is normal even if the number of rotations is erroneously set to be equal to or higher than the allowable rotation speed, and the operation under the third condition is performed. Is determined to be equal to or greater than the allowable value only after the start of the rotation, and the rotation is stopped. There is a problem that it takes a long time to detect the set number of rotations equal to or greater than the allowable value. For example, when the third condition is started at night, an inconvenience such as noticing an error has occurred for the first time in the next morning.

[Object of the invention]

The object of the present invention is to eliminate the above-mentioned disadvantages of the prior art,
An object of the present invention is to make it possible to detect a speed setting error (overspeed setting) of this type of centrifuge at an early stage.

[Summary of the Invention]

The present invention relates to a centrifuge capable of automatically performing two or more types of operations, in which, if the operation is started under the first operating conditions, the permissible rotation speed of the rotating container can be identified. Focusing on having a CPU and RAM, RAM
When operating each of the operating conditions stored in the first condition, at the same time, the set rotation speed as a subsequent condition is also compared with the allowable rotation speed, and all the set rotation speeds compared are equal to or less than the allowable rotation speed of the rotating container. The operation under the first operation condition is continued only in the case, so that the erroneous setting of the set rotation speed can be detected in a short time.

(Example of the invention)

In FIG. 1, the rotating container 1 rotates at a high speed by receiving torque transmission from a rotation speed measuring object 5 fitted to a shaft 6 by a driving device 7. The rotation speed detection device 3 includes, for example, a lamp and a photodiode, and detects the rotation speed of the driving device 7 based on light reflected from the measured object 5 or the like. The rotating container 1 is provided with a to-be-measured object 4 for detecting an allowable number of rotations having a white and black stripe pattern. Like the rotation number detection device 3, the rotation speed detection device 2 includes, for example, a lamp and a photodiode. The permissible rotation speed of the rotating container 1 is detected. Note that the number of stripes of the measured object 4 for detecting the allowable rotation speed is determined in accordance with the allowable rotation speed.

Now, as shown in FIG. 2, two or more types of operating conditions are stored in the RAM 13 via the input interface 15 and the CPU 11 from the operating condition input unit 17, and the operation as shown in FIG. 3 is performed automatically. The permissible rotational speed of the rotating container 1 is identified by the rotational speed detecting device 3 and the CPU 11 constituting the permissible rotational speed identifying means of the rotating container 1.

That is, first, when the rotating container 1 starts to rotate, the frequency information from the overspeed detecting device 2 and the rotational speed information from the rotational speed detecting device 3 are compared to determine the number of stripes of the object 4 for allowable rotational speed detection. Then, from the ROM 12 in which the relationship between the number of stripes of the measuring object 4 for detecting the allowable rotation speed and the allowable rotation speed of the rotating container 1 is input in advance, the measured measuring object 4 for detecting the allowable rotation speed is determined. The permissible number of revolutions corresponding to the number of stripes is identified.

By comparing the permissible number of revolutions identified in this way with the number of revolutions set by the user, it is determined whether or not the rotating container 1 has been set to an overspeed. At the same time, the second
The CPU 11 also compares the second and subsequent operation conditions with the permissible rotation speed identified above to determine whether the set rotation speed after the second condition operation has been set to the overspeed during the first condition operation. , If the overspeed setting has been performed,
This can be detected in a short time after the start of operation.

The identification of the permissible number of rotations of the rotating container 1 may be calculated and calculated based on the ratio of each signal from the overspeed detection device 2 and the number of rotations detection device 3 as shown in the flowchart of FIG.

〔The invention's effect〕

According to the present invention, in a centrifuge capable of automatically performing two or more types of operations, a second operation is performed under the first condition.
Since it is possible to determine whether or not the set rotation speeds after the first rotation are overspeed setting, it is possible to detect an error in the set rotation speed in a short time.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of an overspeed detecting function of a centrifuge according to the present invention, FIG. 2 is a block diagram showing its detecting mechanism, and FIG. 3 automatically performs two or more types of operations. FIG. 4 is an operation state diagram showing a conventional overspeed detection function, and FIG. 5 is a flowchart at the time of a check. In the figure, 1 is a rotating container, 2 is an overspeed detecting device, 3 is a rotational speed detecting device, 4 is a measured object for detecting an allowable rotational speed, 5 is a measured object for detecting a rotational speed, 6 is a shaft, and 7 is a drive. apparatus,
11 is a CPU, 12 is a ROM, 13 is a RAM, 15 is an input interface, and 17 is an operation condition input unit.

Claims (1)

(57) [Claims] A driving device; a rotating container rotatably driven by the driving device; a permissible rotational speed detection target mounted on the rotatable container corresponding to the permissible rotational speed of the rotatable container; Extract the signal from the object to be measured for allowable rotation speed detection,
The apparatus has an allowable number of rotations identifying means for identifying the allowable number of rotations of the rotating container, and further inputs a plurality of operating conditions of the rotating container before starting the operation, and as soon as the operation under the first operating condition is completed, the next operation is sequentially performed. In the centrifuge having the function of continuously performing the operation under the conditions, the set rotation speed as the first operation condition and the set rotation speed as the subsequent operation conditions and the allowable rotation speed of the rotating container are compared, The centrifuge according to claim 1, wherein the operation under the first operation condition is continued only when all the set rotation speeds compared are equal to or less than the allowable rotation speed.