JP2003260385A - Centrifuge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge mechanism of a centrifuge capable of surely draining the water accumulated in the bottom of a chamber. <P>SOLUTION: The centrifuge is provided with a control section 7 for lowering the acceleration gradient at the prescribed number-of-revolution area of a rotor 3 or motor 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifuge having a refrigerator for cooling a chamber and having a mechanism for discharging water accumulated at the bottom of the chamber.

[0002]

2. Description of the Related Art In a conventional centrifuge equipped with a refrigerator,
As shown in FIG. 4, when a pipe-shaped evaporator 12 is wound around the chamber 5 to circulate a refrigerant to perform cooling control by turning on / off, frost adheres to the inner wall of the chamber 5 at the time of turning on and at the time of turning off. Since the frost forms water droplets, the bottom of the chamber 5 is filled with water.

Therefore, as a centrifuge having a mechanism for discharging the above water, an opening / closing valve is provided on the drainage channel, as in Japanese Utility Model Laid-Open No. 6-34746, to open and close when the number of rotations of the rotor is below a certain number. The valve was opened and the water in the chamber was drained to the outside of the centrifuge body via the drain.

[0004]

In the conventional discharge mechanism described above, as shown in FIG. 4, as the rotation of the rotor becomes faster, the air inside the chamber is swirled by the rotor and the bucket to convect at high speed. Therefore, the water accumulated at the bottom of the chamber gathers at the position of B in FIG. 4 while flowing from the position of A in FIG. 4 to the outer periphery of the seal rubber, but with the further high speed rotation of the rotor. Water rides on the conical slope C of the seal mule and convects.
Therefore, the water originally collected at the bottom of the chamber is allowed to freely fall from the opening provided at the bottom of the chamber and drained. However, at the position B in FIG. Since the accumulated time is very short, there was a problem that the amount of drainage decreased.

Further, as the water convectively riding on the conical slope C of the seal mule becomes splashes as shown in the figure and is scattered toward the bucket side, for example, the sample container housed in the bucket is a microplate without a lid. In this case, there is a problem that this water enters as impurities in a plurality of wells formed in the microplate.

An object of the present invention is to solve the above problems and to provide a discharge mechanism capable of reliably discharging the water accumulated at the bottom of the chamber.

[0007]

The above object is to provide a bucket for accommodating a sample container, a rotor for swingably supporting the bucket and rotated by a motor, and a chamber for accommodating the rotor and cooled by a refrigerator. And a drain hose connected to a drainage opening provided at the bottom of the chamber, the centrifugal machine is provided with a control unit for reducing the acceleration gradient in a predetermined rotation speed range of the rotor or the motor.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An automatic centrifuge according to this embodiment will be described with reference to FIGS. FIG. 1 is a partially longitudinal side view showing an embodiment of the automatic centrifuge in this embodiment, and FIGS. 2 and 3 are graphs showing acceleration gradients of the automatic centrifuge in this embodiment. In FIG. 1, an automatic centrifuge 1 includes a handling device 6 for holding and transferring a rectangular parallelepiped sample container 8 with a hand 6a like a microplate, and a bucket 2 on which the container 8 is placed and which is rocked by centrifugal force. , A rotor 3 provided so that the buckets 2 are arranged at even positions at 90-degree intervals and placed on the rotor pin 3a, a motor 4 (for example, a servo motor) directly connected to the rotor 3 by a shaft 9, a motor 4 and a frame A vibration damping member 10 including a spring and a damper provided between the chamber 5, a chamber 5 arranged so as to cover the rotor 3, and a pipe 5 around the outer periphery of the chamber 5 and a refrigerant circulating in the evaporator 12 to cool the chamber 5
Connected to the refrigerator 11 for cooling the water, the control unit 7 for controlling the handling device 6 and the drive motor 4, the drainage opening 20 provided at the bottom of the chamber 5, and the drainage opening 20. A drain hose 21, a drain member 22 provided on the drain hose 21, and a drain tank 23 that stores water discharged from the drain hose 21a.

The handling device 6 described above is
A guide arm 14 that forms a link arm mechanism in which two arms 13a and 13b are linked, and is parallel to each other on an H-shaped base.
a, 14b, and sliders 15a, 15b that slide on the guide members 14a, 14b. The sliders 15a, 15b are fixed to timing belts 16a, 16b and drive stepping motors 17a, 17b. The hand 6a is moved to the left and right by the, and the hand 6a provided at the tips of the arms 13a and 13b is positioned.

Next, a discharge mechanism in an automatic centrifuge using a check valve as the drain member 22 as shown in FIG. 2 will be described. The sample container 8 is accommodated in the plurality of buckets 2 swingably mounted on the pin 3a of the rotor 3 by the handling device 6, and then the door for closing the chamber 5 by the hand 6a of the handling device 6. 1
Close 8. The hand 6a holds the door 18 so that the door 18 is not pushed up by the wind pressure generated by the high-speed rotation of the rotor 3. At this time, the refrigerator 11 is ON / OFF controlled so that the sample temperature in the sample container 8 becomes a preset temperature. After the centrifugal separation is completed, the door 18 is opened by the hand 6a, the sample container 8 is taken out, and the operation of accommodating a new sample container 8 in the bucket 2 is repeated. In this way, since there is a temperature difference between the temperature inside the chamber 5 and the outside air temperature when the door 18 is opened and closed, the frost attached to the chamber 5 becomes a water drop due to the outside air temperature,
It accumulates at the bottom of the chamber 5. Therefore, in order to discharge the water accumulated at the bottom of the chamber 5 to the outside of the centrifuge body, the water is discharged from the drain hose 21 connected to the drainage opening 20 provided at the bottom of the chamber 5 to the drain tank 23.

In order to discharge water efficiently, as shown in FIG. 2, the acceleration gradient is relaxed in a predetermined rotation speed range, and centrifugal acceleration is performed over a period of time. When the rotation speed reaches a predetermined speed, the acceleration is accelerated. The control to be performed becomes important. That is, most of the water accumulated at the bottom of the chamber 5 can be drained by changing the acceleration gradient and taking time for the draining operation. This has been confirmed by the applicant of the present invention through repeated experiments. For example, the predetermined rotational speed range in which the acceleration gradient is made gentle is a value obtained from the experimental result. When the rotational speed reaches about 800 rotational speed, water gathers at the position B in FIG. Since the vehicle rides on the seal rubber 24, the above-described predetermined rotation speed range is set from 800 rotation speeds to 1,500 rotation speeds. Experiments have shown that it takes about 40 seconds to almost completely discharge the water, depending on the amount of accumulated water. Therefore, it is possible to efficiently discharge the accumulated water by controlling the rotation speed range and the time described above.

Further, in the above-described drainage control, when the rotor 3 or the motor 4 rotates at high speed, the fan action of the bucket 2 causes air to flow from the drainage opening 20 into the chamber 5.
Although it acts to suck air into the inside, the suction of air can be blocked by mounting the check valve as the drain member 22 in the direction in which the water in the chamber 5 is drained. As the drain member 22, a sponge containing water, gauze, or the like may be used in addition to the check valve to block the intake of air during high-speed rotation.

Next, another embodiment will be described with reference to FIG.
FIG. 3 shows a graph when a pump is adopted as the drainage member 22 to forcefully drain water. Specifically, the sample container 8 is placed on the bucket 2 by the handling device 6, and the door 1
8 is closed and held by the hand 6a to drive the motor 4 to rotate the rotor 3 and simultaneously drive the pump.
As a result, by driving the pump until it reaches a predetermined number of revolutions of, for example, 1,500 revolutions, for example, by accelerating slowly from 800 revolutions as an acceleration gradient over a period of time, drainage is performed by forced suction by the pump. The required time can be shortened and the water can be almost drained within a few seconds.

From the above, the operation of centrifugal acceleration with a gentle acceleration gradient in a predetermined rotation speed range and the pump driving at a predetermined rotation speed or lower during centrifugal acceleration are performed. It is possible to provide a centrifuge with a short drainage operation time capable of draining most of the accumulated water.

[0015]

According to the present invention, the discharge mechanism of the centrifuge capable of reliably discharging the water accumulated at the bottom of the chamber is provided by providing the control unit for lowering the acceleration gradient in the predetermined rotation speed range of the rotor or the motor. Can be provided.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of an automatic centrifuge according to the present invention.

FIG. 2 is a graph showing an acceleration gradient of the automatic centrifuge according to the present invention.

FIG. 3 is a graph showing an acceleration gradient of the automatic centrifuge according to the present invention.

FIG. 4 is a partially longitudinal side view showing movement of water accumulated at the bottom of a chamber of a conventional automatic centrifuge.

[Explanation of symbols]

1 is an automatic centrifuge, 2 is a bucket, 3 is a rotor, 4 is a motor, 5 is a chamber, 7 is a control unit, 11 is a refrigerator, 20
Is a drainage opening, 21 is a drain hose, and 22 is a drainage member.

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Claims (4)

[Claims] 1. A bucket containing a sample container, a rotor swingably supporting the bucket and rotated by a motor, a chamber containing the rotor and cooled by a refrigerator, and a bottom of the chamber. In the centrifuge including a drain hose connected to the drainage opening provided in, the centrifuge is provided with a control unit that lowers an acceleration gradient in a predetermined rotation speed range of the rotor or the motor. 2. The centrifuge according to claim 1, wherein the drain hose is provided with a check valve. 3. The centrifuge according to claim 1, wherein a pump is provided on the side of the drain hose opposite to the drainage opening. 4. The centrifuge according to claim 3, wherein the pump is operated to discharge the water in the chamber while the rotation speed of the rotor or the motor is lower than a predetermined rotation speed.