JPH0810374Y2 - Centrifuge - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifuge suitable for application when centrifuging a sample.

[0002]

2. Description of the Related Art A centrifuge used for analyzing a sample is configured so that a desired rotor is selected from a plurality of kinds of rotors and is mounted on a rotary shaft of a motor in an exchangeable manner for use. After mounting, the type of the rotor is automatically detected, and the motor is automatically controlled so that the motor rotates at an operating state suitable for the rotor, for example, at a rotation speed.

In order to detect the type of rotor, for example, the means disclosed in Japanese Utility Model Publication No. 3-34279 has been proposed. As shown in FIG. 6, two magnets 21 and 22 are attached to the rotor 18, and these magnets 21 and 22 are attached to the fixed portion 19.
The magnetic sensor 20 for detecting the magnetic flux from the magnet 22 is attached, and from the detection time interval of the two magnets 21 and 22 for one rotation cycle of the motor, these magnets 21,
The angle θ formed by 22 is calculated to determine the rotor type. The arrow f indicates the rotation direction of the rotor 18.

[0004]

In this configuration, considering the angle θ formed by the two magnets 21 and 22 with reference to the magnet first detected by the magnetic sensor 20, the magnet 22 is detected after the magnet 21 is detected. Angle θa (θa <180 °) determined by the time until the detection of (Fig. 6A)
And θb (FIG. 6B), which is determined by the time from when the magnet 22 is detected until when the magnet 21 is detected, when θa = 360 ° −θb = θc, both magnets 21 are used even though they are the same rotor. , The angle θ formed by 22 is different,
There is a problem that it is determined as a different rotor. That is, in FIG. 6A, when the rotor 18 is rotated by θa in the direction of the arrow f, the state is the same as that shown in FIG. 6B. (However, only the signs of the magnets are different). Therefore, in the case of this configuration, the discrimination of the rotor type is effective only within the range of 180 °, and there is a problem that the discrimination range becomes narrow. The present invention avoids the above-mentioned problems and provides a centrifuge capable of discriminating the rotor type within a range of approximately 360 °.

[0005]

In order to solve the above-mentioned problems, in the present invention, a plurality of types of rotors 2 are attached to a rotary shaft 4 of a common motor 3 in a replaceable manner and used. At the same rotational locus R of the rotor 2
The first magnet 5 and the second magnet 6 are attached so that the magnetic flux directions are opposite to each other, and the magnetic fluxes from the first magnet 5 and the second magnet 6 are detected with respect to the fixed portion 8 facing the rotor 2. As described above, the magnetic sensor 7 is attached, and the pulse generation circuit 12 that generates a plurality of N pulses in one rotation in synchronization with the rotation of the motor 3 is provided, and the first magnet 5 and the second magnet 6 are provided.
The number of pulses n is extracted by the counter 13 and the number of pulses n is counted by the counter 13 to determine the type of the rotor 2.

[0006]

According to the present invention, in the magnetic sensor 7, it is possible to reliably determine whether the magnet facing (crossing) the magnet is the first magnet 5 or the second magnet 6, that is, the time T.
Since a and Tb can be discriminated, the angle θ between the reference first magnet 5 and the subsequent second magnet 6 can be discriminated over approximately 360 °.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a centrifuge according to the present invention will be described with reference to the drawings. As shown in FIG. 1, a rotor 2 is arranged in the center of a rotor chamber 1, and the rotor 2 is detachably attached to a rotating shaft 4 of a motor 3 so as to be exchangeable. As shown in FIG. 2, the first magnet 5 and the second magnet 6 are attached to the lower surface of the rotor 2 on the same rotation locus R. In FIG. 2, an arrow f indicates the rotation direction of the rotor 2, and the second magnet 6 has a rotation angle θ with respect to the first magnet 5.
It is just behind. The directions of the magnetic poles of the magnets 5 and 6 are selected so that magnetic fluxes in opposite directions are given to a magnetic sensor 7 described later.

A magnetic sensor 7 is attached to a fixed portion 8 facing the rotor 2 in the rotor chamber 1 at a position facing the rotation locus R. As the magnetic sensor 7, it is possible to use a so-called Hall IC in which a Hall element and a Schmitt trigger circuit to which its output is supplied are integrally incorporated. The output from the Hall IC 7 becomes, for example, high level due to the magnetic flux of the first magnet 5, and the high level state is continued even if the magnetic flux disappears thereafter, and the magnetic flux of the next second magnet 6 (what is called the first magnet 5) It becomes a low level due to (the magnetic flux in the opposite direction), and even after that magnetic flux disappears, the low level state is continued and becomes a high level again by the first magnet 5, and this state is repeated. Of course, a coil can be used instead of the Hall IC 7, but in this case, a flip-flop circuit is required.

A rotary plate 9 is attached to the rotary shaft 4 of the motor 3. As shown in FIG. 3, the rotary plate 9 is formed with N through holes 10 on the same rotation locus.
The number N of the through holes 10 is predetermined. A photo interrupter 11 is provided for the rotary plate 9, and the rotary plate 9 and the rotary plate 9 constitute a pulse generating circuit 12.
That is, by irradiating light from one surface of the rotating plate 9 and receiving it by the phototransistor on the other surface of the rotating plate 9, the pulse Pa shown in FIG. 5A is obtained with the rotation of the motor 3, and the pulse number is the number of pulses of the motor. There will be N per revolution of 3.

Explaining the operation of this configuration, the pulse Pa shown in FIG. 5A is obtained from the pulse generating circuit 12 as the motor 3 rotates. On the other hand, the output P from the magnetic sensor 7
As shown in FIG. 5B, b rises at time Ta when the first magnet 5 faces the magnetic sensor 7, and falls at time Tb when the rotor 2 rotates by an angle θ and the second magnet 6 faces the magnetic sensor 7. . As shown in FIG. 4, the pulse Pa from the pulse generating circuit 12 and the signal Pb from the magnetic sensor 7 are supplied to the counter 13, where the signal Pb as shown in FIG. 5C.
The number n of pulses in the high level period of is counted. This pulse number n corresponds to the rotation angle θ shown in FIG.

The number of pulses n thus obtained is input to a computer (microcomputer) 14, where it is compared with a command (operating condition) from an operating device 15, and from this number of pulses n, the rotor 2 is identified. It is automatically determined whether it is of a type, and thereby the rotation speed of the motor 3 is automatically controlled and displayed on the display 16.

In the above example, a pair of magnets 5 and 6 are provided on one rotation locus R, but the second, third ...
・ It is possible to discriminate more types of rotors by providing the rotation loci of the above and mounting magnets on these trajectories in the same manner as described above, and by similarly providing the magnetic sensors for these magnets. Becomes According to this configuration, the position of the second magnet 6 with respect to the first magnet 5, that is, the angle θ is set to 3
Since the selection can be made within the range of 60 °, more kinds of rotors 2 can be provided as compared with the conventional one.

[0013]

According to the centrifuge according to the present invention, the first
Even if the second magnet is installed within the angular range of about 360 ° with the magnet as the reference position, the position of the second magnet can be reliably detected. Therefore, when detecting within the conventional 180 ° rotation angle range. It has an effect that more kinds of rotors can be discriminated compared to. Further, since the microcomputer only needs to determine the type of rotor by the number of pulses from the counter, the workload of this microcomputer is small, the microcomputer can be simplified, and there is an effect that it can be supplied at a low price.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of a centrifuge according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a plan view of a rotary plate that can be used in the present invention.

FIG. 4 is a circuit diagram that can be used in this device.

FIG. 5 is a waveform diagram illustrating the operation of FIG.

FIG. 6 is a diagram for explaining a conventional rotor discrimination means, where A is a case where an angle formed by two magnets is θa,
B is the case where the angle formed by the two magnets is θb.

[Explanation of symbols]

 1 rotor chamber 2 rotor 3 motor 5 first magnet 6 second magnet 7 magnetic sensor

Claims (1)

[Scope of utility model registration request] 1. A centrifuge in which a plurality of types of rotors are exchangeably attached to a rotary shaft of a common motor for use, and magnetic flux directions are opposite to each other on the same rotation locus of the rotors. A first magnet and a second magnet that are attached, a magnetic sensor that is attached to a fixed portion facing the rotor so as to detect magnetic flux from the first magnet and the second magnet, A pulse generation circuit that generates a plurality of pulses within one rotation in synchronization with the rotation, and a pulse within the rotation angle of the first magnet and the second magnet is extracted from the plurality of pulses to determine the number of pulses. A centrifuge having: a counter for counting.