JP2016083654A - Centrifugal machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform efficient centrifugation processing with less power consumption.SOLUTION: A centrifugal machine rotor chamber 14 is depressurized. A space between an exhaust port 13A and a vacuum pump 20 is connected in parallel with a first exhaust path 21, and a second exhaust path 22. Therefore the centrifugal machine rotor chamber 14 can be depressurized by any one of the first exhaust path 21, and the second exhaust path 22. When the centrifugal machine rotor chamber 14 is depressurized by only the first exhaust path 21, pressure of the centrifugal machine rotor chamber 14 is maintained at Pwhich is cracking pressure of a check valve 50. The second exhaust path 22 has a solenoid valve 51. Operation of the solenoid valve 51 is controlled by a control part 30, unlike control of operation of the check valve 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a centrifuge that rotates a sample at high speed.

  A centrifuge (centrifuge) is used to separate or analyze substances having different densities by centrifugal force during high-speed rotation. In a centrifuge, a sample to be separated is provided in a rotor (centrifuge rotor) that rotates at a high speed, and the rotor is provided in a rotor chamber in a bowl. Here, the rotation speed (rotation speed: rpm) of the motor for rotating the rotor is determined, and the rotor rotates at this rotation speed (setting speed) for a predetermined time, and the settling speed is 150,000 rpm at the maximum. Sometimes it is said. In such a case, rotation is inhibited by the friction between the air around the rotor and the rotor, and heat is generated. On the other hand, the temperature during the centrifugation process is required to be constant, and this temperature is lower than room temperature, for example, 4 ° C.

  For this reason, in the centrifuge (ultra-centrifuge) in which the settling speed is set to 40000 rpm or more, the inside of the bowl (rotor chamber) is decompressed and cooled. For decompression, a vacuum pump (decompression pump) is connected to the bowl, and the pressure in the rotor chamber is, for example, about 13 Pa. Further, in a centrifuge (high-speed cooling centrifuge) in which the settling speed is 20000 to 30000 rpm, the pressure is not reduced as much as in the ultracentrifuge, but a large-sized cooler is used, and heating of the rotor is suppressed. The configuration of an ultracentrifuge that performs both decompression and cooling is described in Patent Documents 1 and 2, for example.

JP2011-139976A JP2013-150939A

  In the high-speed cooling centrifuge, cooling is performed by a refrigeration pipe through which the cooled refrigerant flows. Since it is extremely difficult for the refrigeration piping to be in direct contact with the rotor that rotates at high speed, the refrigeration piping is wound around a bowl that forms the rotor chamber. In this case, heat conduction between the refrigeration pipe and the rotor is performed via the bowl and the air in the rotor chamber. For this reason, in the situation where the rotor chamber was decompressed, the thermal conductivity between the refrigeration pipe and the rotor decreased, and it took a long time to bring the rotor chamber to a desired temperature. Further, in the ultracentrifuge, since the rotor is cooled by an electronic cooling element (Peltier element) provided in the lower part of the bowl in a state where the rotor chamber is evacuated, it takes a long time for cooling.

  For this reason, for example, in the technique described in Patent Document 2, the rotor is cooled in a state where the rotor chamber is not decompressed, the rotor chamber is decompressed after the rotor reaches a desired temperature, and then high-speed rotation of the rotor is started. .

  However, when such an operation is performed, it takes time to start high-speed rotation, and thus it is difficult to perform an efficient centrifugation process. In addition, since a high-speed cooling centrifuge requires a large-sized cooler, there is a problem that efficient centrifugal separation processing is difficult and power consumption is large.

  The present invention has been made in view of such problems, and an object thereof is to provide an invention that solves the above problems.

In order to solve the above problems, the present invention has the following configurations.
The centrifuge of the present invention is a centrifuge having a configuration in which a centrifuge rotor chamber containing a centrifuge rotor that contains a sample and rotates is decompressed and the centrifuge rotor is cooled, The gas flow between the one and the other by being connected between the other and the gas when the pressure difference between the one and the other is greater than a predetermined cracking pressure. A check valve that circulates between the one and the other is used, and the pressure in the centrifuge rotor chamber is controlled by the check valve.
In the centrifuge of the present invention, the pressure on the centrifuge rotor chamber side is higher than the pressure on the decompression pump side between the decompression pump and the centrifuge rotor chamber where the check valve decompresses the centrifuge rotor chamber. The centrifuge rotor chamber and the decompression pump are communicated with each other when the pressure difference between the pressure on the centrifuge rotor chamber side and the pressure on the decompression pump side is larger than the cracking pressure. It is characterized by.
The centrifuge of the present invention includes a first exhaust path for communicating the centrifuge rotor chamber and the decompression pump via the check valve, and a valve that can be opened and closed separately from the first exhaust path. And a second exhaust path for communicating the centrifuge rotor chamber and the decompression pump.
The centrifuge of the present invention opens the valve, depressurizes the centrifuge rotor chamber by the second exhaust path, and then closes the valve to thereby close the centrifuge rotor chamber by the first exhaust path. It has a control part which performs control which decompresses.
The centrifuge of the present invention closes the valve and depressurizes the centrifuge rotor chamber by the first exhaust path, and then opens the valve to open the centrifuge rotor chamber to the second exhaust path. It is characterized by comprising a control part which performs control to reduce pressure by.
In the centrifuge of the present invention, the control unit performs control to open the valve after the temperature of the centrifuge rotor reaches a preset temperature.
The centrifuge of the present invention includes a plurality of the first exhaust paths each including the check valves set with different cracking pressures, and a selected one of the plurality of first exhaust paths. The centrifuge rotor chamber is configured to be decompressed.
In the centrifuge of the present invention, a plurality of types of the centrifuge rotor can be used, an identifier corresponding to the type is provided in the centrifuge rotor, the centrifuge rotor identification sensor for recognizing the identifier, and the identifier Is used to recognize the type of the centrifuge rotor, select one of the plurality of first exhaust paths according to the type, and decompress the centrifuge rotor chamber by the one first exhaust path. And a control unit that performs control.
The centrifuge of the present invention connects the centrifuge rotor chamber and the atmosphere via the check valve, and the pressure difference between the atmosphere and the centrifuge rotor chamber side is larger than the cracking pressure. A leakage path for communicating the centrifuge rotor chamber and the atmosphere is provided.
The centrifuge of the present invention is configured such that a motor inner space, which is a space provided with a rotor in a drive motor that rotationally drives the centrifuge rotor, communicates with the centrifuge rotor chamber, and is connected to the drive motor. The motor internal space and the atmosphere are connected via the check valve, and when the pressure difference between the air and the motor internal space is larger than the cracking pressure, the motor internal space and the air are connected. It is characterized by having a leak path for communication.
The centrifuge of the present invention includes an exhaust path that is connected to the drive motor and serves as a path for decompressing and exhausting the internal space of the motor and the centrifuge rotor chamber.
The centrifuge of the present invention is characterized in that, in the drive motor, the leak path is provided on a side far from the centrifuge rotor chamber, and the exhaust path is provided on a side close to the centrifuge rotor chamber.
The centrifuge of the present invention is characterized in that, in the drive motor, the exhaust path is provided on a side far from the centrifuge rotor chamber, and the leak path is provided on a side close to the centrifuge rotor chamber.
The centrifuge of the present invention is characterized in that, in the leak path, the check valve is connected to the centrifuge rotor chamber via a valve that can be opened and closed.
The centrifuge of the present invention is characterized in that, in the leak path, the check valve is connected to the inner space of the motor via a valve that can be opened and closed.
The centrifuge of the present invention is characterized in that, in the leakage path, the check valve is connected to the atmosphere via a valve that can be opened and closed.
The centrifuge of the present invention includes a control unit that performs control to depressurize the centrifuge rotor chamber by closing the valve after the valve is opened and air is introduced into the leak path. And
In the centrifuge of the present invention, the control unit performs control to close the valve after the temperature of the centrifuge rotor reaches a predetermined set temperature.
The centrifuge of the present invention includes a plurality of the leak paths each including the check valves set with different cracking pressures, and the atmosphere is introduced into a selected one of the plurality of leak paths. It is characterized by being configured.
In the centrifuge of the present invention, a plurality of types of the centrifuge rotor can be used, an identifier corresponding to the type is provided in the centrifuge rotor, the centrifuge rotor identification sensor for recognizing the identifier, and the identifier A control unit for recognizing the type of the centrifuge rotor, selecting one of the plurality of leak paths according to the type, and performing control for introducing the atmosphere into the one leak path, It is characterized by doing.
In the centrifuge of the present invention, the control unit determines whether or not to operate the decompression pump according to the type.

  Since the present invention is configured as described above, in the centrifuge having a configuration in which the centrifuge rotor is cooled and the centrifuge rotor chamber is depressurized, an efficient centrifugation process is performed with low power consumption. Can do.

It is a figure which shows the structure of the centrifuge used as the 1st Embodiment of this invention. It is a figure explaining the structure and operation | movement of a check valve. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber in the 1st example of the operating method of the centrifuge used as the 1st Embodiment of this invention, the rotational speed of a centrifuge rotor, temperature. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber, the rotational speed of a centrifuge rotor, temperature, in the 2nd example of the operating method of the centrifuge used as the 1st Embodiment of this invention. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber in the 3rd example of the operating method of the centrifuge used as the 1st Embodiment of this invention, the rotational speed of a centrifuge rotor, temperature. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber in the 4th example of the operating method of the centrifuge used as the 1st Embodiment of this invention, the rotational speed of a centrifuge rotor, temperature. It is a figure which shows typically the relationship between the rotational speed in several types of centrifuge rotors, and a windage loss. It is a figure which shows the structure of the modification of the centrifuge used as the 1st Embodiment of this invention. It is a figure which shows typically the relationship between the rotational speed in a single centrifuge rotor, and a windage loss for every pressure of a centrifuge rotor chamber. It is a figure which shows the structure of the centrifuge used as the 2nd Embodiment of this invention. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber in the 1st example of the operating method of the centrifuge used as the 2nd Embodiment of this invention, the rotational speed of a centrifuge rotor, temperature. It is a figure which shows time passages, such as the pressure of the centrifuge rotor chamber, the rotational speed of a centrifuge rotor, and temperature in the 2nd example of the operating method of the centrifuge used as the 2nd Embodiment of this invention. It is a figure which shows the structure of the 1st modification of the centrifuge used as the 2nd Embodiment of this invention. It is a figure which shows the structure of the 2nd modification of the centrifuge used as the 2nd Embodiment of this invention. It is a figure which shows the structure of the centrifuge used as the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the drive motor used in the centrifuge used as the 3rd Embodiment of this invention. It is a figure explaining operation | movement of the check valve used in the centrifuge used as the 3rd Embodiment of this invention. It is a figure which shows the time passage of the pressure of the centrifuge rotor chamber in an example of the operating method of the centrifuge used as the 3rd Embodiment of this invention. It is a figure which shows the structure of the modification of the centrifuge used as the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the drive motor used in the modification of the centrifuge used as the 3rd Embodiment of this invention.

  A centrifuge according to an embodiment of the present invention will be described. In the centrifuge according to the embodiment of the present invention, a check valve that opens and closes due to a pressure difference between both sides of a connected portion is used. The pressure (cracking pressure) serving as the opening / closing threshold is determined in advance. A check valve, a relief valve or the like having the same function may be used.

(First embodiment)
In the centrifuge 10 according to the first embodiment, the check valve is provided between the centrifuge rotor chamber and a decompression pump that exhausts (depressurizes) the centrifuge rotor chamber. For this reason, the check valve operates according to the pressure difference between the centrifuge rotor chamber side and the pressure reduction pump side. FIG. 1 is a diagram schematically showing the configuration of the centrifuge 10. In the centrifuge 10, a centrifuge rotor 12 that is rotated by a drive motor 11 is provided in a centrifuge rotor chamber 14 in a bowl 13. An openable / closable door 15 is provided above the bowl 13 so that the centrifuge rotor chamber 14 is sealed. Further, outside the bowl 13, the cooling pipe 16 winds the bowl 13 in an annular shape around the rotation axis of the centrifuge rotor 12. A refrigerator 17 is connected to the cooling pipe 16, and the refrigerant whose temperature is controlled (cooled) by the refrigerator 17 circulates in the cooling pipe 16. That is, the cooling pipe 16 and the refrigerator 17 function as a cooling mechanism for cooling the bowl 13 and the centrifuge rotor 12. Although the centrifuge rotor 12 is not in direct contact with the cooling pipe 16, the centrifuge rotor 12 is cooled by the cooling pipe 16 through the air in the bowl 13 and the centrifuge rotor chamber 14 by the above configuration. A temperature sensor 18 for measuring the temperature of the inner surface of the bowl 13 is provided on the inner surface of the bowl 13. Since it is difficult to directly measure the temperature of the centrifuge rotor 12 that rotates at high speed, the temperature of the inner surface of the bowl 13 detected by the temperature sensor 18 is used as a guideline for the temperature of the centrifuge rotor 12. Or the temperature of the centrifuge rotor 12 is estimated.

  The centrifuge rotor chamber 14 is depressurized (evacuated). For this purpose, a decompression pump (vacuum pump) 20 is provided, and the bowl 13 is provided with an exhaust port 13A for exhausting the inside of the bowl 13 (centrifuge rotor chamber 14) under reduced pressure. The exhaust port 13 </ b> A and the decompression pump 20 are connected in parallel by a first exhaust path 21 and a second exhaust path 22. For this reason, the centrifuge rotor chamber 14 can be decompressed by either the first exhaust path 21 or the second exhaust path 22.

  In addition, the centrifuge 10 is provided with a control unit 30 that controls the drive motor 11, the decompression pump 20, the refrigerator 17, and the like. The control unit 30 controls the drive motor 11, the decompression pump 20, the refrigerator 17, and the like according to the operation of the operation panel 31 by the operator so that an appropriate centrifugation process is performed. Centrifugal acceleration applied to the sample in the centrifuge rotor 12 is determined by the rotational speed (number of rotations) of the drive motor 11, and the control is performed by the control unit 30 controlling the current that drives the drive motor 11. The control unit 30 is also connected with a temperature sensor 18 and a pressure gauge (sensor) / vacuum gauge (sensor) (not shown) that recognizes the pressure (depressurized state) in the centrifuge rotor chamber 14. For this reason, the control part 30 can also perform said control according to the temperature and pressure detected by these.

  The centrifuge rotor 12 is selected and used by an operator from a plurality of types. The shape of the centrifuge rotor 12 varies depending on the type. For this reason, even if it is set as the same settling rotation speed (set rotation speed), the centrifugal acceleration applied to a sample and the inertia moment of the centrifuge rotor 12 differ according to this kind. For this reason, it is necessary to recognize the type of the centrifuge rotor 12 used when performing the centrifugation process. Further, the windage loss varies depending on the type of the centrifuge rotor 12. For this reason, as will be described later, by controlling the depressurization state of the centrifuge rotor chamber 14 in accordance with the type of the centrifuge rotor 12, the centrifuge process can be performed more efficiently. For this reason, an identification mark (identifier) 12A corresponding to this type is provided on the surface of the centrifuge rotor 12, and an identifier sensor (centrifuge rotor identification sensor) 19 for reading this mark is provided inside the bowl 13. Is fixed. The output of the identifier sensor 19 is input to the control unit 30, and the control unit 30 can recognize the type of the centrifuge rotor 12 that is mounted.

  The combination of the identification mark 12A and the identifier sensor 19 is already a known technique, and an array of recesses (holes) formed in the centrifuge rotor 12 is used as an identification mark 12A, which is an eddy current sensor (distance sensor). A method of detecting by a certain identifier sensor 19 and discriminating the type of the centrifuge rotor from this arrangement pattern, a magnet arrangement for detecting a magnet and a magnet such as a Hall element or a magnetoresistive element, and the like. A method of discriminating the type from the pattern can be used. Further, as another centrifuge rotor identification method, a centrifuge may be provided with a camera, and the type of the centrifuge rotor may be identified by an image taken by the camera.

  The centrifuge 10 is characterized by a path for depressurizing the centrifuge rotor chamber 14 (first exhaust path 21 and second exhaust path 22) and a control method for depressurizing the centrifuge rotor chamber 14. As shown in FIG. 1, the first exhaust path 21 and the second exhaust path 22 connect the exhaust port 13 </ b> A and the decompression pump 20 in parallel. Below, the structure of the 1st exhaust path 21 and the 2nd exhaust path 22, and these control methods are demonstrated.

  First, the first exhaust path 21 will be described. FIG. 2 is a diagram schematically showing the configuration of the first exhaust path 21. The first exhaust path 21 has a tubular shape connecting the exhaust port 13A and the decompression pump 20, and a check valve 50 is provided therein. For this reason, when the check valve 50 is opened, the centrifuge rotor chamber 14 is evacuated (depressurized) by the decompression pump 20 through the first exhaust path 21, and when the check valve 50 is closed, The centrifuge rotor chamber 14 is not exhausted via one exhaust path 21.

The check valve 50 automatically opens and closes according to the pressure difference between both sides, that is, the centrifuge rotor chamber 14 (exhaust port 13A) side and the decompression pump 20 side. Here, if the pressure on the centrifuge rotor chamber 14 side (one side) is P _C and the pressure on the decompression pump 20 side (the other side) is P _P , the centrifuge rotor chamber 14 is a decompression pump during decompression. Since the pressure is reduced only from the 20 side, generally P _C ≧ P _P. In the check valve 50, a ball 50A and a spring 50B that closes the flow path by urging the ball 50A toward the centrifuge rotor chamber 14 are provided. Therefore, in the check valve 50, the cracking pressure _{P S} in accordance with the spring 50B is _set, only in the case of _{P C> P S + P P} ( or _{P C -P P> P S)} , the check valve 50 is opened It becomes. P _S is, for example, about 1 / 3-1 / 2 atm (about 34 kPa). This pressure is set within a range in which sufficient heat conduction can be performed by air between the bowl 13 and the centrifuge rotor 12 in the centrifuge rotor chamber 14.

FIG. 2A shows a situation when the centrifuge rotor chamber 14 is depressurized from the atmospheric pressure. In FIG. 2A, the pressure P _{C in} the centrifuge rotor chamber 14 is the atmospheric pressure P _ATM (about 101 kPa). In a state where the vacuum pump 20 is not turned on, since the pressure _{P P} in the vacuum pump 20 side is atmospheric pressure _{P ATM,} a _{P C = P P, P C} <P S + P P , and the check valve 50 is closed It becomes. That is, the first exhaust path 21 is blocked by the check valve 50.

FIG. 2B shows a state after the decompression pump 20 is turned on from the state of FIG. Figure in the state of 2 (a), since the check valve 50 is closed, the vacuum pump 20 in this state is turned on, the pressure P _P is greatly reduced from the atmospheric pressure in a short time, P _C = the _{P ATM} >> P P. Therefore, the above P _C > P _S + P _P is satisfied, the check valve 50 is opened, and the pressure P _{C in the} centrifuge rotor chamber 14 starts to decrease from P _ATM . That is, the first exhaust path 21 is opened, and the centrifuge rotor chamber 14 is decompressed. At this time, the ball 50A becomes a resistance at the time of exhaust, and at the time of exhaust, a force is applied to the ball 50A on the pressure reducing pump 20 side, and the spring 50B contracts due to the exhaust resistance. The pressure exerted by the spring 50B is P _S ′ (P _S ′> P _S ).

Thereafter, as long as the condition of P _C > P _S ′ + P _P is satisfied, the check valve 50 is kept open, so the pressure P _C of the centrifuge rotor chamber 14 continues to decrease. The pressure P _P on the pressure reducing pump 20 side also continues to decrease, but saturates near a certain pressure P _P1 . Therefore, the pressure _{P C} of the centrifuge rotor chamber 14 is continued to _decrease, the relation _{P C = P S '+ P} P is satisfied. In this case, as shown in FIG. 2C, the check valve 50 is closed again. That is, the first exhaust path 21 is closed again. In this case, since the state spring 50B is the extended, the pressure _{P S} 'on the spring 50B is relative to the ball 50A is equal to _{P S.} Therefore, when the vacuum centrifuge rotor chamber 14 only by the first exhaust path 21, the pressure in the centrifuge rotor chamber 14 is maintained in the sum of P _S and P _P1 is a cracking pressure of the check valve 50 The

As described above, while _{P S} is set to about 1 / 3-1 / 2 _{atm, P P1} is determined by the exhaust capacity of the vacuum pump 20, in general, for example 1 kPa (about 0.01 atm) or less It is. Therefore, P _S >> P _P1 and the state of FIG. 2C is realized when P _C ≈P _S. Therefore, by using the above-mentioned check valve 50, the pressure in the centrifuge rotor chamber 14 from atmospheric pressure to a cracking pressure P _S, it is possible to reduce the pressure through the first exhaust path 21. Alternatively, the first exhaust path 21, it is not possible to vacuum centrifuge rotor chamber 14 to a pressure below P _S. That is, by such a check valve 50, opening and closing operation of the first exhaust path 21 in response to the cracking pressure P _S is automatically performed. Cracking pressure _{P S} is the set of spring 50B, it can be set in advance.

  On the other hand, in the second exhaust path 22, an electromagnetic valve (valve) 51 is provided instead of the check valve 50. The electromagnetic valve 51 is a valve whose opening / closing operation is controlled using, for example, a solenoid. Unlike the check valve 50, the operation is controlled by the control unit 30. Therefore, the centrifuge rotor chamber 14 can be decompressed by the second exhaust path 22 until the electromagnetic valve 51 is opened and the pressure determined by the exhaust capacity of the decompression pump 20 (for example, 10 kPa or less).

  In the centrifuge 10 described above, in particular, the use of the check valve 50 in the first exhaust path 21 enables efficient centrifugal separation processing. At this time, the control unit 30 controls the electromagnetic valve 51 in the second exhaust path 22 so that the centrifugal separation process can be performed more efficiently. This will be described below.

FIG. 3 shows an example (first example) of time lapse of the pressure P _{C of} the centrifuge rotor chamber 14, the rotation speed of the centrifuge rotor 12, and the temperature of the centrifuge rotor 12 in the centrifuge 10. Here, the operation when the second exhaust path 22 is not used, that is, when the electromagnetic valve 51 is always closed will be described. Here, P _P and P _S (P _S ′) + P _P are also shown for reference. _Here, up to the point of _{t 30} is decompression pump 20 is stopped and the centrifuge rotor chamber 14, it is assumed decompression pump 20 are both atmospheric _{(P ATM).} Therefore, the first exhaust path 21 at the time of t ₃₀ is the state of FIG. 2 (a), i.e., up to the point of t ₃₀ is a closed first exhaust path 21.

From this state, the vacuum pump 20 at time t ₃₀ is turned on, P _P starts to decrease. Thereafter, since P _P decreased, P _c = P _S + P _P at time t ₃₁ , and thereafter, the centrifuge rotor is driven by the first exhaust path 21 while the relationship of P _C > P _S ′ + P _P is satisfied. Chamber 14 is depressurized. Then, at the time of P _P is reduced to a pressure determined by the exhaust capacity of the vacuum pump 20 (substantially zero in FIG. 3), but P _C is also reduced along with this, t ₃₃ became P _C ≒ P _S the street, since the first exhaust path 21 is closed, since is not reduced pressure, the state of P _C ≒ P _S is maintained.

During this _time, from _{t 30,} until _{t 32} as the _{t 30 <t 32 <t 33} , the rotational speed of the centrifuge rotor 12 is _{raised, t 32} later, the rotational speed is constant 22000Rpm (settling operation ). Therefore, in the example of FIG. 3, in the P _C originally wind loss increases large state, because the rotational speed of the centrifuge rotor 12 is low, windage loss is suppressed.

Meanwhile, since _{the P C} is the centrifuge rotor 12 in a state close to _{P ATM} is particularly efficiently cooled, as shown in FIG. _3, lowering of the temperature of the centrifuge rotor 12 in the period until t 30 _{~t 32} The rate is large. _However, in the following _{t 32} or _{t 33} is also _{to P C} is maintained at approximately _{P S,} centrifuge rotor 12 is efficiently cooled. That is, by using the check valve 50, the pressure in the centrifuge rotor chamber 14 is automatically suppressed from becoming _PS or lower, so that the centrifuge rotor 12 can be efficiently cooled. At this time, P _S is cooled is performed efficiently, and windage losses are also set to the extent suppressed. For this reason, the power consumption of the refrigerator 17 and the drive motor 11 can be reduced.

FIG. 4 shows another example (second example) of time elapse of the pressure P _{C of} the centrifuge rotor chamber 14, the rotational speed of the centrifuge rotor 12, and the temperature of the centrifuge rotor 12 in the centrifuge 10. . In this example, the second exhaust path 22 is also used. For this reason, the state of opening and closing of the electromagnetic valve 51 is also described on the lower side of the figure.

Here, the vacuum pump 20 from the time point t _40, which is turned on, is an electromagnetic valve 51 is opened, that is, the second exhaust path 22 is opened. For this reason, the centrifuge rotor chamber 14 is efficiently decompressed using the second exhaust path 22 together with the first exhaust path 21. Therefore, it is possible to increase the decreasing rate of P _C than in FIG. Then, at time _{t 41} became _{P C} ≒ _{P S,} the electromagnetic valve 51 is closed, after the closed second exhaust path 22, the pressure _{P C} of the centrifuge rotor chamber 14, a first This depends only on the exhaust path 21. However, at this time, the first exhaust path 21 is also closed as described above.

Thereafter, at a time point _{t 42} became _{P C> P} S + _{P P} and _{P C} is increased by small leak or the like of the centrifuge rotor chamber 14, to open the first exhaust path 21 again, and again _{P C} ≒ P _The centrifuge rotor chamber 14 is depressurized until _S is reached. Therefore, since the pressure of the centrifuge rotor chamber 14 is constant in the vicinity of P _S. whether it is a time point t ₄₁ (whether a P _C ≒ P _S), when the pressure gauge is provided in the centrifuge rotor chamber 14, the controller 30 determines the output to the original can do. However, it is not necessary to strictly control this timing. If _P C> _{P S} at time t _41, since is depressurized until _{P C} ≒ _{P S} by the first exhaust path 21 as in FIG. _{3, P} at time _{t 41} C <P If it is _S , since the first exhaust path 21 is closed thereafter, the centrifuge rotor chamber 14 is not further decompressed. Thus, for _example, a _{t 41} may be after a predetermined time has elapsed from the time point of _{t 40.}

Changes in the rotational speed and temperature of the centrifuge rotor 12 during this time are the same as in the example of FIG. However, in the example of FIG. 4, by using the second exhaust path 22 to the pressure-decrease start early, which reduces the time until the P _C ≒ P _S. For this reason, the rate of increase in the rotational speed of the centrifuge rotor 12 can be increased accordingly. That is, a more efficient centrifugation process can be performed.

FIG. 5 shows another example (third example) of time lapse of the pressure P _{C of} the centrifuge rotor chamber 14, the rotational speed of the centrifuge rotor 12, and the temperature of the centrifuge rotor 12 in the centrifuge 10 described above. . In this example, contrary to the second example, the second exhaust path 22 is used after a sufficient time has elapsed after the start of the centrifugation process.

In FIG. 5, t ₅₄ is the time after that shown in FIG. 4 has been carried out settling operation at this time, the rotational speed of the centrifuge rotor 12 is constant. Further, as described above, the pressure of the centrifuge rotor chamber 14 is maintained in a state of P _C ≒ P _S. In this case, it is assumed that the set temperature (target temperature) of the centrifuge rotor 12 is 10 ° C. At the time of t _54, the temperature of the centrifuge rotor 12 has not yet reached this preset temperature, the temperature continues to decrease. As described above, in this state, the electromagnetic valve 51 is closed.

Thereafter, at a time point t ₅₅ where the temperature of the centrifuge rotor 12 is lowered to a set temperature, is an electromagnetic valve 51 is opened. Thus, _{P C} is greatly reduced from _{P S,} it approaches _{P P} (substantially zero in FIG. 5). Thereby, since the windage loss of the centrifuge rotor 12 can be further reduced, the power consumption of the drive motor 11 can be reduced. Moreover, since the heat_generation | fever from the centrifuge rotor 12 falls further by this, the cooling capability by the cooling piping 16 can be reduced, and the power consumption of the refrigerator 17 can also be reduced. That is, the power consumption during the centrifugal separation process in the centrifuge 10 can be reduced. whether it is a time point t ₅₅ (whether the temperature of the centrifuge rotor 12 has reached the set temperature) can be controller 30 is determined based on the output of the temperature sensor 18.

Figure 6 shows the centrifuge 10 described above, the pressure P _C of the centrifuge rotor chamber _14, the rotational speed of the centrifuge rotor 12, another example of the time course of the temperature of the centrifuge rotor 12 (fourth example) . In this case, since the set temperature of the centrifuge rotor 12 is high or the centrifuge rotor chamber 14 is precooled in advance, the time required for cooling is extremely short. In this case, as in the case of FIG. 5, rather than maintaining a high P _C to about P _S for temperature control, preferably better to preferentially suppressing windage loss by reducing the P _C. Therefore, in FIG. 6, from the start of operation of the vacuum pump 20 (time point t _60), to maintain the open state of the electromagnetic valve 51, and open the second exhaust path 22 at all times. As a result, the time until the settling operation can be shortened, and the power consumption of the drive motor 11 and the refrigerator 17 can be reduced as in the example of FIG. As described above, the control unit 30 can perform such control based on the output of the temperature sensor 18.

  Next, control according to the type of the centrifuge rotor 12 will be described. As described above, the centrifuge rotor 12 is provided with a plurality of types (shapes), and the windage loss and the cooling efficiency differ depending on the types. For example, when the outer diameter of the centrifuge rotor 12 is large, the speed difference from the air at the outer peripheral portion increases, so that the windage loss increases. On the other hand, in the configuration of FIG. Therefore, the cooling efficiency is increased. Conversely, when the outer diameter of the centrifuge rotor 12 is small, the windage loss is small and the cooling efficiency is low. Such a situation is schematically shown in FIG. 7 as the relationship between the rotational speed and the windage loss. Here, two types of A and B are assumed as the types of the centrifuge rotor 12, and the outer diameter of the rotor A is larger than the outer diameter of the rotor B. The windage loss shown here is assumed to be at atmospheric pressure. Moreover, the cooling capacity limit shown here is a limit at which temperature control (cooling) is no longer difficult when the windage loss exceeds this. For this reason, if the centrifuge rotor chamber 14 is subjected to centrifugal separation in a state of atmospheric pressure, it is necessary to operate at a rotational speed in a range where the windage falls below this limit. As described above, the windage loss at the same rotational speed is larger in the rotor A, but since the cooling efficiency is higher, the cooling capacity limit is also larger in the rotor A.

The rotor A with a large outer diameter is used to process a large amount of samples at once, and the maximum rotational speed _NAMAX of the rotor A is such that the strength of the centrifuge rotor can withstand the load caused by centrifugal force. It is set _smaller than the maximum rotation speed N _BMAX . For this reason, the windage loss in the rotor A is lower than the cooling capacity limit even when the rotational speed is _NAMAX . For this reason, when the rotor A is used, the centrifugal separation process can be performed after temperature control is performed even if the rotor chamber 14 is at atmospheric pressure.

On the other hand, since the rotor B with a small outer diameter rotates a small amount of sample at a high speed, in the case of N _B1 where the rotation speed is lower than N _BMAX , the windage loss becomes equal to the cooling capacity limit, and the rotation speed higher than this. Then, the windage damage exceeds its cooling capacity limit. For this reason, when the rotor B is used, it is necessary to decompress the rotor chamber 14 when the rotation speed is set to be _NB1 or more.

  For this reason, the control unit 30 recognizes the type of the centrifuge rotor 12 from the output of the identifier sensor 19, and determines whether or not to operate the decompression pump 20 based on the type and the settling rotational speed (the rotational speed during the settling operation). As a result, unnecessary decompression of the centrifuge rotor chamber 14 can be suppressed, power consumption of the centrifuge 10 can be reduced, and the efficiency of the centrifugation process can be improved. .

  In the configuration of FIG. 1, only one check valve 50 (first exhaust path 21) is used. However, it is possible to perform more control according to the type of the centrifuge rotor 12 by using a plurality of check valves 50. . FIG. 8 is a diagram showing a configuration of a centrifuge 110 as a modification of the centrifuge 10 described above in correspondence with FIG. In the centrifuge 110, the first exhaust path 21 in the centrifuge 10 is replaced with a first exhaust path first branch path 211 and a first exhaust path second branch path 212 connected in parallel. ing. The first exhaust passage first branch passage 211 and the first exhaust passage second branch passage 212 are respectively provided with check valves 501 and 502 in the same manner as described above, and electromagnetic valves are respectively provided on the exhaust port 13A side. (Valves) 511 and 512 are provided. The functions of the check valves 501 and 502 are the same as those of the check valve 50, and the functions of the electromagnetic valves 511 and 512 are the same as those of the electromagnetic valve 51. The opening and closing of the electromagnetic valves 511 and 512 is controlled by the control unit 30.

If the electromagnetic valve 511 is opened and the electromagnetic valve 512 is closed, the first exhaust path first branch path 211 functions in the same manner as the first exhaust path 21 in the centrifuge 10, and the electromagnetic valve 511. If the valve is closed and the electromagnetic valve 512 is opened, it is clear that the first exhaust path second branch path 212 functions in the same manner as the first exhaust path 21 in the centrifuge 10. Therefore, if the cracking pressures of the check valves 501 and 502 are P _S1 and P _S2 (P _S1 > P _S2 ), the electromagnetic valves 511 and 512 are opened and closed, and the first exhaust path first branching path 211 is operated. If any one of the first exhaust path and the second branch path 212 is selected, the pressure in the centrifuge rotor chamber 14 is set to either P _S1 or P _{S2 in} the case of FIGS. be able to.

With such a configuration, the centrifugal separation process can be performed more efficiently, and the power consumption of the centrifuge 110 can be reduced. This point will be described below. Figure 9 shows the relationship between the rotational speed and the windage loss in one certain centrifuge rotor, similarly to FIG. 7 for each pressure P _C of the centrifuge rotor chamber 14. Here, _{P C is, P ATM} (atmospheric _{pressure), P C1 (P C1 <} P ATM), is set to three types of _{P C2 (P C2 <P C1} ). Windage is smaller the lower the _{P C.}

In the characteristics of FIG. 9, the temperature control (cooling) of the centrifuge rotor is such that when the centrifuge rotor chamber 14 is at atmospheric pressure and the rotation speed is N ₁ or less, the pressure in the centrifuge rotor chamber 14 is _PC1 . In this case, this is possible when the rotational speed is N ₂ or less, and when the pressure in the centrifuge rotor chamber 14 is PC ₂ , the rotational speed is N _max (maximum rotational speed) or less. However, in order to shorten the cooling time, (closer to P _C to the atmospheric pressure) is not as much as possible to perform the decompression of the centrifuge rotor chamber 14 is preferred. For this purpose, in FIG. 9, it is preferable to operate within a range close to the cooling capacity limit within a range not exceeding the cooling capacity limit. For this reason, in FIG. 9, it is preferable to drive | operate in the range shown as the continuous line. That is, when the rotation speed is N ₁ or less, the centrifuge rotor chamber 14 is set to atmospheric pressure, and when the rotation speed exceeds N ₁ and is N ₂ or less, the pressure of the centrifuge rotor chamber is set to PC ₁ and the rotation speed is set. There it is preferable to set the pressure of the centrifuge rotor chamber and P _C2 when more than N _2.

P _S1 = P _C1 , P _S2 = P _C2 , and if the rotational speed is N ₁ or less, the decompression pump 20 is not turned on, and if the rotational speed exceeds N ₁ and is N ₂ or less, the first exhaust When the route first branch 211 is used and the rotational speed exceeds N ₂ , the first exhaust route second branch 212 is used, and the operation is performed within the range indicated by the solid line in FIG. The control unit 30 can perform such switching operation (opening / closing operation of the electromagnetic valves 211A and 212A) according to the designated rotation speed. In the example shown by the solid line in FIG. 9, the switching operation is performed when the windage loss reaches the cooling capacity limit. However, in practice, the switching operation is performed with a margin left until the cooling capacity limit. Preferably it is done. Further, in the configuration of FIG. 8, two branch paths (first exhaust paths) of the first exhaust path are provided as described above, but three or more branch paths (first exhaust paths) are provided. There are also more options for these settings.

Moreover, the setting of the pressure of the centrifuge rotor chamber 14 can be performed according to the type of the centrifuge rotor. That is, the first exhaust path first branch passage 211 for the centrifuge rotor 12 capable of temperature control of the P _C is high even if sufficiently centrifuge rotor 12, for controlling the temperature of the centrifuge rotor 12 It may use the first exhaust passage second branch passage 212 for the centrifuge rotor 12 to be necessary to reduce the windage loss by reducing the P _C to.

(Second Embodiment)
In the centrifuge 120 according to the second embodiment, the check valve is provided between the centrifuge rotor chamber and the atmosphere. Since the atmospheric pressure is constant, the check valve operates only according to the pressure on the centrifuge rotor chamber side. FIG. 10 is a diagram showing the configuration of the centrifuge 120 correspondingly. In this centrifuge 120, a leak path 60 is connected in the middle of an exhaust path 61 that connects the exhaust port 13A and the decompression pump 20. The leak path 60 is provided with a check valve 52 having the same function as the check valve 50, and an electromagnetic valve (valve) 53 is provided on the centrifuge rotor chamber 14 side of the check valve 52. The direction of the check valve 52 in FIG. 10 is opposite to the direction of the check valve 50 in FIGS. 1 and 2, that is, when the check valve 52 is open, the right pressure is higher than the left pressure.

An example (first example) of the time elapse of the pressure P _{C of} the centrifuge rotor chamber 14, the rotational speed of the centrifuge rotor 12, and the temperature of the centrifuge rotor 12 in this centrifuge 120 is shown in FIG. Shown in Here, first, the case where the electromagnetic valve 53 is normally open will be described. In this case, the centrifuge rotor chamber 14 at the time of t ₇₀ is atmospheric pressure, wherein the pressure reducing pump 20 is turned on. In that this situation corresponds to FIG. 2 (a) is the same as the time point t ₃₀ in the case of FIG. 3. However, in this case, regardless of the check valve 52, centrifuge rotor chamber 14 is decompressed by the decompression pump 20, P _C is lowered. P _C is lowered _at the time of _{t 71} became _{P C + P S = P ATM} , the check valve 52 is opened. For this reason, thereafter, the atmosphere is introduced into the exhaust path 61 via the leak path 60 via the check valve 52. _Further, since _{t 71,} the same principle as in FIG. 3, _{P C} is approximately equal maintained at a value of _P ATM -P _S. That is, the _{P S} which is set at the centrifuge 10 of the by replacing the _P ATM -P _S, it is possible to same operation in the centrifuge 120. At this time, the rotational speed and temperature of the centrifuge rotor 12 are controlled in the same manner as in FIG.

Next, an operation when the electromagnetic valve 53 is also opened and closed will be described. FIG. 12 shows this operation (second example) corresponding to FIG. Here, the opening and closing of the electromagnetic valve 53 is also shown on the lower side. This operation is performed following the operation of FIG. Thus, _{t 80} in FIG. 12 is a time after the operation of FIG. 11. In the state shown in FIG. 11, the temperature of the centrifuge rotor 12 gradually decreases and does not reach the set temperature of 10 ° C. Thereafter, the temperature has reached the set temperature at the time of t ₈₁ in FIG. 12. By the electromagnetic valve 53 is closed at this time, since the inflow of air into the centrifuge rotor chamber 14 through the leakage path 60 stops, P _C decreases further increased from P _ATM -P _S. For this reason, windage loss can be further reduced. This operation is the same as the operation of FIG. That is, this can reduce power consumption during the centrifugation process.

Corresponding to the configuration of FIG. 8, a plurality of leak paths 60 can also be provided in this configuration. FIG. 13 shows the configuration of the centrifuge 130 having such a configuration corresponding to FIG. Here, a first leak path (leak path) 601 and a second leak path (leak path) 602 are provided in parallel, and check valves 521 (cracking pressure P _SS1 ), 522 (cracking pressure P _SS2 ), electromagnetic valves, respectively. (Valves) 531 and 532 are provided. Similar to the centrifuge 110 of FIG. 8, by controlling the opening and closing of the electromagnetic valves 531 and 532, the pressure _{P C} of the centrifuge rotor chamber _14, control the two types of _{P ATM -P SS1, P ATM -P} SS2 can do. As a result, control according to the rotational speed and type of the centrifuge rotor 12 can be performed, and thereby the efficiency of the centrifugal separation process and the reduction in power consumption can be achieved. The same applies to the fact that three or more leak paths can be provided, and the on / off control of the decompression pump 20 can be performed together with the selection of the leak path.

  In the above example, the leak path is connected to the exhaust path from the exhaust port 13A to the decompression pump 20, but a leak path can be provided at other locations as long as the same effect is obtained. For example, it can also be directly provided at a location other than the exhaust port 13 </ b> A in the bowl 13.

  Further, in the centrifuge 120 shown in FIG. 10, the electromagnetic valve 53 is provided between the centrifuge rotor chamber 12 and the check valve 52. However, like the centrifuge 140 shown in FIG. The chamber 12 and the check valve 52 may be directly connected, and the electromagnetic valve 53 may be provided between the check valve 52 and the atmosphere. Even in such a case, it is obvious that the same operation as the centrifuge 120 is possible. As described above, a plurality of leak paths can be provided in parallel.

(Third embodiment)
A check valve is also used in the centrifuge according to the third embodiment, but in this case, since the control of the degree of vacuum of the centrifuge rotor chamber and the temperature control of the centrifuge rotor are performed in the same manner as described above, the check valve is small. In addition to performing efficient centrifugal separation with power consumption, the cooling efficiency of the drive motor can also be increased. As a result, a smaller drive motor can be employed, and the cooling fan can be reduced in size or eliminated.

  FIG. 15 is a diagram showing the configuration of the centrifuge 150 corresponding to FIG. Also in the centrifuge 150, the centrifuge rotor chamber 14 is evacuated (depressurized) by the decompression pump 20, and the bowl 13 and the centrifuge in the centrifuge 150 are cooled by the cooling pipe 16 (refrigerator 17). The machine rotor 12 is cooled. The centrifuge rotor 12 is rotationally driven by a drive motor 71 disposed on the lower side of the centrifuge rotor 12 and outside the bowl 13. However, in this centrifuge 150, the space inside the drive motor 71 is connected to the centrifuge rotor chamber 14, and the space inside the drive motor 71 and the centrifuge rotor chamber 14 are decompressed simultaneously. As in the second embodiment, the centrifuge 150 is also configured to introduce the atmosphere into the exhaust path 716. At this time, the atmosphere is also introduced into the drive motor 71. The As an exhaust path 716 and a path for introducing air into the drive motor 71, a leak path 715 provided below the drive motor 71 is used, and a check valve 54 is provided in the leak path 715. As a path for exhausting the centrifuge rotor chamber 14 and the drive motor 71, an exhaust path 716 provided on the upper side of the drive motor 71 is used, and the exhaust path 716 is connected to the decompression pump 20. For this reason, introduction of air into the exhaust path 716 and decompression of the centrifuge rotor chamber 14 are performed via the inside of the drive motor 71.

  FIG. 16 is a cross-sectional view showing the structure of the drive motor 71 along the rotating shaft 12B of the centrifuge rotor 12. As shown in FIG. In the drive motor 71, an electric motor rotor (rotor) 711 to which the rotary shaft 12B is fixed and an electric motor stator (stator) 712 arranged around the motor rotor 711 are provided in a motor case 713. An electric motor rotation shaft 711 </ b> A that is a rotation shaft of the electric motor rotor 711 is rotatably supported by bearings 714 at two upper and lower portions in the motor case 713. The uppermost part of the rotating shaft 12B is located in the centrifuge rotor chamber 14, and a centrifuge rotor holder 12C to which the centrifuge rotor 12 is detachable is fixed.

  The drive motor 71 is an alternating current induction type, and operates by passing a current through the coil of the motor stator 712 and the conductor portion of the motor rotor 711. Here, the upper side of the rotating shaft 12B is located in the centrifuge rotor chamber 14, and the bowl 13 and the motor case 713 are combined to connect the space inside the centrifuge rotor chamber 14 and the motor case 713. It is supposed to be configured. For this reason, in the centrifuge 150, the centrifuge rotor 12 and the motor rotor 711 that rotate at high speed are both provided in a reduced-pressure atmosphere. Thereby, these rotational movements can be performed particularly smoothly.

  While the centrifuge rotor 12 generates heat due to friction with the surrounding air during rotation, in the drive motor 71, in addition to the motor rotor 711 generating heat due to friction with the surrounding air during rotation, Heat is also generated when a current is passed through the conductor portion of the motor rotor 711 and the coil of the motor stator 712. For this reason, the drive motor 71 is configured such that the motor case 713 is air-cooled, and a large number of cooling fins 713A are formed around the motor case 713 to increase the heat radiation area. The centrifuge 150 is also provided with a cooling fan (not shown) for sending air to the motor case 713 side.

  With this configuration, even if the motor stator 712 directly fixed to the motor case 713 generates heat, the motor stator 712 is cooled with high efficiency. On the other hand, since the contact point between the motor rotor 711 and the motor case 713 is only the bearing 714, it is difficult to cool the motor rotor 711 in the same manner as the motor stator 712. The cooling of the electric motor rotor 711 is performed via the surrounding air in the same manner as the cooling of the centrifuge rotor 12 in the centrifuge rotor chamber 14. For this reason, from the viewpoint of smoothly rotating the electric motor rotor 711, it is preferable to depressurize the surrounding space (motor inner space 713B), while from the viewpoint of efficiently cooling the electric motor rotor 711 or the drive motor 71. Therefore, it is preferable not to depressurize the motor internal space 713B. These points are the same as the situation in the rotation and cooling (temperature control) of the centrifuge rotor 12.

  For this reason, a leakage path 715 is provided below the motor case 713 in the drive motor 71. A check valve 54 is connected to the leak path 715 in the same direction as the centrifuge 120 (the direction in which the check valve 54 opens when the pressure on the left side in the drawing is sufficiently lower than the pressure on the right side). . Further, an exhaust path 716 connected to the decompression pump 20 is connected to the upper right side of the motor case 713 in FIG. For this reason, when the inside of the centrifuge rotor chamber 14 is decompressed, the motor internal space 713B is also decompressed.

In this case, the time course of the pressure P _C (= pressure in the motor inner space 713B) in the centrifuge rotor chamber 14 after the exhaust of the motor inner space 713B and the centrifuge rotor chamber 14 is started is shown in FIG. Here, at the start of exhaust (time t ₉₀ ), P _C = P _ATM (atmospheric pressure).

FIGS. 17A and 17B are views showing the state of the check valve 54 corresponding to FIGS. 2A and 2B. In the figure, the left side of the check valve 54 is the motor inner space 713B (centrifuge rotor chamber 14) side, the right side is the atmosphere (pressure P _ATM ), and the direction of the check valve 54 is reversed left and right as compared with FIG. . This operation is the same in the centrifuge 120 described above.

Figure 17 (a) shows the status of the check valve 54 in the state close to the time _{t 90} in Figure 18. Here, a pressure _P C _{= P C1} ≒ _{P ATM} in the motor space 713B, in this state, rightward force exerted on the ball 50A is a _{P S} as cracking pressure of the spring _{50B, P} C1 + P _S, the left Since the force becomes P _ATM and P _C1 + P _S ≈P _ATM + P _S > P _ATM , the ball 50A is urged to the right side, the check valve 54 is closed by the ball 50A, and the leak path 715 is closed. In this state, since the motor space 713B air is not introduced, the motor space 713B and centrifuge rotor chamber 14 is evacuated by vacuum pump 20, the pressure P _C after a time t ₉₀ is rapidly decreased.

_P C _{= P C2} becomes P _C decreases, as shown in FIG. 17 _(b), when the _{P C2 + P S '<P} ATM, since the ball 50A is biased to the left, the leak path 715 The air is introduced into the motor internal space 713B. However, situations in which the motor in the space 713B and centrifuge rotor chamber 14 is evacuated by vacuum pump 20 does not change, and since the check valve 54 is opened and closed by the boundary conditions of _{P C2 + P S '= P} ATM, after all, in FIG. 18, _{P C} is after the time _{t 91} is maintained at a value close to _P ATM -P _S. Here, when the flow in this manner atmosphere within the check valve 54, for receiving the air flow resistance by ball 50A and the like, when the pressure due to the air path resistance and _{P F, P C is P} ATM -P _S It is maintained at a value of about -P _F. Here, _{P S} is set to, for example, about 0.8 atm (81kPa), when the small _{that P F} is negligible, _{P C} is maintained at a value of about 0.2 atm (about 20 kPa). As in the case described above, this pressure allows heat conduction between the bowl 13 and the centrifuge rotor 12 and reduces frictional heat between the air and the centrifuge rotor 12 under this pressure. Is set. The characteristics shown in FIG. 18 are the same as the characteristics shown in FIG.

Therefore, after time _{t 91} in Figure 18, it flows into the motor space 713B cold air through a check valve 54. In FIG. 16, the air flow in the motor case 713 at this time is indicated by arrows. The motor case 713 has such a shape that air smoothly flows from the lower side to the upper side through the gap between the electric motor rotor 711 and the electric motor stator 712 therein. In particular, the motor rotor 711 can be efficiently cooled by the forced air cooling by the air flow. Note that in this configuration, the minimum pressure becomes P _ATM -P _S -P _F about the, as performance required for the vacuum pump 20, the ultimate pressure is sufficient as long as it can maintain this minimum pressure. For this reason, for example, this ultimate pressure may be sufficiently higher than 1 kPa.

  In this case, the temperature of the air flowing into the motor inner space 713B rises due to the heat generated by the motor rotor 711 and the like. On the other hand, since the centrifuge rotor 12 cooled in the centrifuge rotor chamber 14 is located on the downstream side of this flow, the time required for temperature control of the centrifuge rotor 12 may be increased due to the temperature rise of the air. . However, since most of the heated air is exhausted by the decompression pump 20 from the exhaust path 716 below the centrifuge rotor chamber 14 before reaching the centrifuge rotor chamber 14, the temperature of the air is increased. The adverse effect of the rise on the temperature control of the centrifuge rotor 12 can be reduced.

  For this reason, in this centrifuge 150, the degree of vacuum control of the centrifuge rotor chamber 14 and the temperature control of the centrifuge rotor 12 are appropriately performed, and the cooling efficiency of the drive motor 71 can be increased. At this time, the cooling efficiency of the drive motor 71 is enhanced by using only the air flowing into the centrifuge rotor chamber 14 without adding electrically driven parts. For this reason, such an effect can be obtained without increasing the power consumption.

In the configuration of FIG. 15, only the check valve 54 is connected to the leak path 715. On the other hand, similarly to the configuration of FIG. 10, an electromagnetic valve whose opening / closing is controlled by the control unit 30 may be provided in series with the check valve 54. At this time, the electromagnetic valve may be provided either on the atmosphere side of the check valve 54 or on the motor internal space 713B side. As a result, when the drive motor 71 is sufficiently cooled, the same operation as in FIG. 12 can be performed. Similar to the arrangement of FIG. 13, and branches the leakage path is mounted a plurality of check valves having different cracking pressure P _S, respectively, and also the same that can be used by switching them as appropriate using an electromagnetic valve . Similarly, the control unit 30 can select the optimum leak path according to the type of the centrifuge rotor 12, perform the on / off control of the decompression pump 20 together with the selection of the leak path, and further reduce the power consumption. is there.

  In the configuration of FIG. 15, the exhaust path 716 is provided in the upper part of the drive motor 71. However, the exhaust path may not be provided on the drive motor side, and the exhaust path may be directly connected to the centrifuge rotor chamber. Even in such a case, it is clear that the same effect can be obtained if the exhaust path is connected near the drive motor. That is, in the above configuration, the leak path needs to be connected to the drive motor, but the exhaust path does not need to be connected to the drive motor, and the degree of freedom of the installation location is great.

  Conversely, when the exhaust path is provided on the drive motor side, it can be provided at a location different from FIG. FIG. 19 is a diagram showing a configuration of a centrifuge 160 that is a modification of the centrifuge 150 described above. In the drive motor 81 used in the centrifuge 160, the positions of the leak path 715 and the check valve 54 connected thereto, the exhaust path 716 and the decompression pump 20 connected thereto are switched. The internal structure of the drive motor 81 and the air flow in this case are shown in FIG. 20 corresponding to FIG. In the drive motor 81, similarly to the drive motor 71, an electric motor rotor (rotor) 711, an electric motor stator (stator) 712, a motor case 713, a bearing 714, and the like are provided.

  However, the positions of the leak path 715 and the exhaust path 716 are reversed from those of the drive motor 71. For this reason, the air flow in the drive motor 81 is different from that of the drive motor 71. In this case, since the motor inner space 713B is on the downstream side of the centrifuge rotor chamber 14, the heat generated in the drive motor 81 adversely affects the cooling of the centrifuge rotor 12 unlike the centrifuge 150 described above. It is not. On the other hand, the air that has been cooled and increased in humidity in the centrifuge rotor chamber 14 may flow into the drive motor 81 that is an electric circuit. However, by providing the leak path 715 in the upper part of the drive motor 81, the air introduced from the leak path 715 is mixed into the high-humidity air, so that the humidity decreases in the motor internal space 713B. Can be reduced.

  In the second and third embodiments, the check valve is provided at a location communicating with the atmosphere. In this case, the place on the atmosphere side of the check valve is arbitrary as long as the atmosphere can be introduced through this portion. For example, a check valve may be provided inside the centrifuge housing, which may be a location away from the centrifuge body. Alternatively, piping such as dry nitrogen instead of the atmosphere may be connected to the check valve and introduced.

  In the above example, the check valve having the structure shown in FIGS. 2 and 17 is used. Similarly, the check valve has a function of automatically controlling opening and closing according to the pressure difference between both sides. If it is, it can be used similarly. In this case, if a configuration having a variable cracking pressure is used, cracking can be performed by providing these independently without using the plurality of first exhaust paths and the plurality of leak paths as shown in FIGS. It is possible to perform the same operation by adjusting the pressure. Moreover, if it is a valve whose opening and closing is controlled from the outside, it can be used similarly to the above-mentioned electromagnetic valve. Also, a method of connecting the decompression pump for decompressing the rotor chamber and the exhaust port (bowl) is arbitrary.

10, 110, 120, 130, 140, 150, 160 Centrifuge (centrifuge)
11, 71, 81 Drive motor 12 Centrifuge rotor 12A Identification mark (identifier)
12B Rotating shaft 12C Centrifuge rotor holder 13 Bowl 13A Exhaust port 14 Centrifuge rotor chamber 15 Door 16 Cooling piping (cooling mechanism)
17 Refrigerator (cooling mechanism)
18 Temperature sensor 19 Identifier sensor (rotor identification sensor)
20 Pressure reducing pump 21 First exhaust path 22 Second exhaust path 30 Control unit 31 Operation panel 50, 52, 54, 501, 502, 521, 522 Check valve 50A Ball 50B Spring 51, 53, 511, 512, 531, 532 Solenoid valve (valve)
60 Leak path 61, 716 Exhaust path 211 First exhaust path First branch path (first exhaust path)
212 1st exhaust path 2nd branch path (1st exhaust path)
601 First leak path (leak path)
602 Second leak path (leak path)
711 Motor rotor (rotor)
711A Motor rotating shaft 712 Motor stator (stator)
713 Motor case 713A Cooling fin 713B Motor inner space 714 Bearing 715 Leak path

Claims (21)

A centrifuge having a configuration in which a centrifuge rotor chamber containing a centrifuge rotor that accommodates and rotates a sample is decompressed and the centrifuge rotor is cooled,
When the gas flow between the one and the other is controlled by being connected between the one and the other, and the pressure difference between the one and the other is greater than a predetermined cracking pressure A check valve is used for flowing the gas between the one and the other,
The centrifuge characterized in that the pressure in the centrifuge rotor chamber is controlled by the check valve.   The pressure on the centrifuge rotor chamber side is higher than the pressure on the decompression pump side between the decompression pump and the centrifuge rotor chamber where the check valve decompresses the centrifuge rotor chamber, and the centrifuge rotor 2. The centrifuge rotor chamber and the decompression pump are provided to communicate with each other when a pressure difference between a pressure on the chamber side and a pressure on the decompression pump side is larger than the cracking pressure. The centrifuge described in. A first exhaust path for communicating the centrifuge rotor chamber and the decompression pump via the check valve;
In addition to the first exhaust path, a second exhaust path for communicating the centrifuge rotor chamber and the decompression pump via a valve capable of opening and closing;
The centrifuge according to claim 2, further comprising:   Control for depressurizing the centrifuge rotor chamber by the first exhaust path by closing the valve after depressurizing the centrifuge rotor chamber by the second exhaust path by opening the valve The centrifuge according to claim 3, further comprising a section.   Control for controlling the decompression of the centrifuge rotor chamber by the second exhaust path by opening the valve after the valve is closed and the centrifuge rotor chamber is decompressed by the first exhaust path The centrifuge according to claim 3, further comprising a section. The controller is
6. The centrifuge according to claim 5, wherein control is performed to open the valve after the temperature of the centrifuge rotor reaches a predetermined set temperature.   A plurality of first exhaust passages each having the check valve set with different cracking pressures, and the centrifuge rotor chamber is formed by a selected one of the plurality of first exhaust passages; The centrifuge according to claim 3, wherein the centrifuge is configured to be depressurized. A plurality of types of the centrifuge rotor is usable, and an identifier corresponding to the type is provided in the centrifuge rotor,
A centrifuge rotor identification sensor for recognizing the identifier;
The type of the centrifuge rotor is recognized by the identifier, one of the plurality of first exhaust paths is selected according to the type, and the centrifuge rotor chamber is defined by the one first exhaust path. A control unit for controlling the pressure reduction;
The centrifuge according to claim 7, comprising:   The centrifuge rotor chamber and the atmosphere are connected via the check valve when the pressure difference between the atmosphere and the centrifuge rotor chamber side is larger than the cracking pressure. The centrifuge according to claim 1, further comprising a leak path that communicates with the centrifuge. The motor inner space, which is a space provided with a rotor inside the drive motor that rotationally drives the centrifuge rotor, is configured to communicate with the centrifuge rotor chamber,
The motor inner space is connected to the drive motor, connects the motor inner space and the atmosphere via the check valve, and the pressure difference between the atmosphere and the motor inner space is larger than the cracking pressure. The centrifuge according to claim 1, further comprising a leak path that allows the atmosphere to communicate with the atmosphere.   The centrifuge according to claim 10, further comprising an exhaust path connected to the drive motor and serving as a path for exhausting the motor space and the centrifuge rotor chamber under reduced pressure.   12. The centrifuge according to claim 11, wherein in the drive motor, the leak path is provided on a side far from the centrifuge rotor chamber, and the exhaust path is provided on a side close to the centrifuge rotor chamber. .   12. The centrifuge according to claim 11, wherein in the drive motor, the exhaust path is provided on a side far from the centrifuge rotor chamber, and the leak path is provided on a side close to the centrifuge rotor chamber. .   10. The centrifuge according to claim 9, wherein the check valve is connected to the centrifuge rotor chamber through a valve capable of opening and closing in the leak path.   The centrifuge according to any one of claims 10 to 13, wherein, in the leak path, the check valve is connected to the inner space of the motor via a valve that can be opened and closed. .   The centrifuge according to any one of claims 9 to 13, wherein, in the leak path, the check valve is connected to the atmosphere via a valve that can be opened and closed.   15. The apparatus according to claim 14, further comprising a control unit that performs control to depressurize the centrifuge rotor chamber by closing the valve after the valve is opened and air is introduced into the leak path. Item 20. The centrifuge according to any one of Items 16 to 16. The controller is
The centrifuge according to claim 17, wherein control is performed to close the valve after the temperature of the centrifuge rotor reaches a predetermined set temperature.   A plurality of the leak paths each having the check valves set with different cracking pressures are provided, and the atmosphere is introduced into a selected one of the plurality of leak paths. The centrifuge according to any one of claims 14 to 16. A plurality of types of the centrifuge rotor is usable, and an identifier corresponding to the type is provided in the centrifuge rotor,
A centrifuge rotor identification sensor for recognizing the identifier;
A controller that recognizes the type of the centrifuge rotor by the identifier, selects one of the plurality of leak paths according to the type, and performs control to introduce the atmosphere into the one leak path;
The centrifuge according to claim 19, comprising:   The centrifuge according to claim 8 or 20, wherein the control unit determines whether or not to operate the vacuum pump according to the type.