JPH05138073A - Centrifuge drive circuit - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a centrifuge, and an object of the present invention is to select optimal operating characteristics such as acceleration / deceleration suitable for a rotor to be used without operating error, It is to enable centrifugation with high efficiency, high reliability, and high reproducibility. A control circuit 3 receives rotor type information determined by a rotor determination circuit 5 via a rotor type setting device 7 for setting the type of rotor 1 or a rotor detector 6 for automatically detecting the type of rotor 1. The optimum operation data for the rotor 1 is extracted from the rotation characteristic storage unit 4, and the motor 2 is controlled to realize the optimum centrifugal separation. The operation data of the rotation characteristic storage unit 4 can be set and changed by the rotation characteristic setting device 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifuge equipped with a rotor which is rotationally driven by a drive motor.

[0002]

2. Description of the Related Art A conventional centrifuge is controlled by acceleration and deceleration characteristics as shown in FIGS. 2 to 5, and these characteristics differ depending on the size of the rotor, which is the load of the motor. . Figure 2 is a acceleration characteristics when the power supplied to the motor is maximum, the characteristics of the large rotor moment of inertia (hereinafter referred to as I _L rotor) is R, the moment of inertia small rotor (hereinafter, referred to as Is rotor ) Is S. FIG. 3 shows the characteristics when the rotor is loaded with a density gradient liquid or the like for acceleration, and is a reduction region (a region where the number of revolutions is equal to or lower than Na, usually Na = about 500 to
It is a gradual acceleration of 1,000 min- ¹ ),
The characteristic of the I _L rotor is T, and the characteristic of the Is rotor is U. 4, FIG. 5 is a speed reduction characteristics, a characteristic of the case 4 is obtained by multiplying the maximum braking force of the centrifuge, characteristic V is I _L rotor, characteristic W is of Is rotor. FIG. 5 shows a case where the separated sample is gently braked in the low speed region (a region below N _d ) so as not to disturb during deceleration, and the characteristic X is the _IL rotor,
Characteristic Y is that of the Is rotor.

[0003]

The acceleration characteristics R and S in FIG. 2 are characteristics of the I _L rotor (rotor having large inertia moment) and the Is rotor (rotor having small inertia moment) at the maximum rotation torque of the centrifuge. If the characteristic S is a bad characteristic in terms of mechanical strength, mechanical vibration, safety or centrifugal separation performance, and if the rotational acceleration needs to be reduced like the characteristic S ', the Is rotor will have the characteristic S'. When the _IL rotor is accelerated by the rotational torque at that time, the characteristic becomes R ', and the acceleration time becomes long. Is rotor acceleration time t _s
There is a t _s' t _s even in the '<t _R, the user is less likely to feel that a long time, if t _R of I _L rotor feel very long become a t _R'. Using both I _L rotor and Is rotor, both rotors and good centrifugal respectively separated to obtain at minimum becomes acceleration time the characteristics R, but it can control in S, in a conventional centrifuge, (1) Since the control relating to the rotational torque during acceleration is uniform, the acceleration control of the I _L rotor and the Is rotor is determined by the characteristic S ′ of the Is rotor, and therefore the I _L rotor must be controlled by the characteristic R ′.

Alternatively, (2) if the rotational torque during acceleration can be made variable by setting, the setting is erroneously operated because it is irrelevant to each rotor in operation.

There are problems such as In addition, in FIG. 3, 0 min
Although From ¹ is a case of slow acceleration control the rotation range of up to N _a, I combined the beginning of rotational torque Is rotor
_{When the} slow acceleration control is performed on the _L rotor, the time t _o is required until the rotation starts as shown by the characteristic T, and the acceleration time becomes long.
The rotational torque of the first conversely sometimes rapid acceleration when driving the Is rotor fit I _L rotor. Incidentally, the acceleration time to rotate after N _a t _u and t _T -t _o shall be controlled. Therefore, in the conventional centrifuge, in (3) slow accelerator control, the time from the start of acceleration to the start of rotation of the rotor varies depending on the size of the rotor, and efficient operation cannot be performed.

There is a problem. Further, although FIG. 4 shows the deceleration characteristic, similarly to FIG. 2, when the Is rotor cannot be operated with the characteristic W and must be controlled with the characteristic W ′, if the _IL rotor is controlled with the same braking torque, the characteristic V ′ is obtained. , The deceleration time becomes longer from t _v to t _v ', which deteriorates the operation efficiency. Thus, forced to control (4) Deceleration Control of I _L rotor and Is rotor for control over the rotation torque during deceleration is uniform is 'determined by, therefore I _L rotor characteristic V' characteristics of Is rotor W I don't get.

Alternatively, (5) if the braking torque during deceleration can be changed by setting, the setting is erroneously operated because it has no relation to each rotor in operation.

There are problems such as Although FIG. 5 is a case of controlling by the slow brake the rotation region to the rotation stop of N _d, I _L rotor and when subjected to the same braking torque Is rotor, respectively for the deceleration time of the slow brake t _x , T _Y , and the deceleration time varies. The problem with the conventional centrifuge in this case is that (4),
Same as (5).

In the conventional centrifuge, there is a method (generally called a memory function or a program function) of storing operating parameters and calling the data when operating. As shown in FIG. 15, if the parameter group required for operation is one operation data and the n operation data are D ₁ , D ₂ , D ₃ ... Dn, for example, 1, 2, 3 ... n is coded and the operation data is stored in the storage unit with a code, and the code is input during operation to call the operation data. In the case of this method, the relationship between the rotor used and the operation data (or its code) to be called is not unique, and therefore the above-mentioned problems (2) and (5) are caused, and the optimum centrifugation is This may result in poor centrifugation results such as sample turbulence.

An object of the present invention is to obtain a centrifuge capable of selecting and operating optimal operating characteristics such as acceleration / deceleration suitable for a rotor to be used without operating error.

[0011]

In order to achieve the above object, in the present centrifuge, information on the type of rotor used in the centrifuge is input to a control circuit, and the information is used to determine acceleration, deceleration, etc. of a predetermined characteristic. The control data that can be realized are selected and the motor is controlled by the data.

The optimum characteristics such as acceleration and deceleration are determined by distinguishing the motor control data according to the unique characteristics of the rotor to be used, such as the moment of inertia, weight, maximum outer diameter, and statistical acceleration / deceleration time. This can be realized by storing the differentiated control data in the storage unit in advance and controlling the withdrawal based on the rotor type information. Further, the conditions to be decided on the user side in terms of centrifugation such as acceleration / deceleration, for example, set rotational speed, temperature, operation time, magnitude of acceleration, magnitude of braking, etc., can be set in advance in the storage unit by the user. In the same manner, it can be realized by similarly controlling the withdrawal based on the information on the type of the rotor.

[0013]

When a plurality of rotors of different types are exchanged and used in the centrifuge equipped with the above-mentioned means, the control circuit obtains the type information of the rotors so that the control circuit determines the type of the rotors used. It works to control the motor by selecting characteristic data that can be discriminated and can execute centrifugal separation by optimal acceleration and deceleration of the rotor. Since the characteristic data is made up of the acceleration torque, braking torque, and optimum values of centrifugal separation of the rotor using the unique properties of the rotor used (for example, the moment of inertia etc.) and the set value from the user as parameters. , This centrifuge has optimum motor acceleration,
It works like centrifuging in deceleration control.

[0014]

The present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a motor 2 for rotationally driving a rotor 1 for centrifuging a mixed solution containing a sample is controlled by a control circuit 3. The motor 2 has a mechanism in which a plurality of rotors of different types can be replaced and attached. In order to distinguish the type of the rotor 1 and perform centrifugal separation for each rotor by a predetermined acceleration / deceleration control or the like, the rotor determination circuit 5 can arbitrarily set the type of the rotor used by the user. The rotor type information is fetched via the type setting device 7 or via the rotor detector 6 having the function of automatically detecting the rotor type. Further, the rotor discriminating circuit 5 sends the rotor type information to the control circuit 3
Output to. The rotation characteristic storage unit 4 stores operation data including acceleration / deceleration characteristic data for each rotor type.
When the control circuit 3 receives the rotor type information from the rotor discrimination circuit 5, the control circuit 3 extracts the operation data suitable for the received rotor type from the rotation characteristic storage unit 4 and controls the motor 2. An example of operation data storage of the rotation characteristic storage unit 4 is shown in FIG.
Shown in. The types of rotors are R ₁ , R ₂ , R ₃ , ... Rn and n
If there is one, the rotor discrimination circuit 5 encodes each as 1, 2, 3, ... N, and sends the encoded data to the control circuit 3 as rotor type information. The operation data is stored in advance in the rotation characteristic storage unit 4 for each encoded data as D ₁ , D ₂ , D ₃ , ... Dn, and the control circuit 3 stores the operation data based on the encoded data in the rotation characteristic. Withdraw from part 4. In the operation data of the rotation characteristic storage unit 4,
Some of the data can be changed by the rotation characteristic setting device 8 (variable data) and some cannot be changed (invariable data).
The invariable data is an operating condition that is restricted in terms of mechanical strength, mechanical vibration, safety, centrifugal performance, etc. (for example, the operable characteristic S ′ with respect to the characteristic S of FIG. 2 described above, (Characteristic W ′ with respect to characteristic W in FIG. 4 and unique characteristics of the rotor, etc.). Further, the variable data is data other than the above-mentioned invariable data, such as set rotation speed, temperature, operating time, magnitude of acceleration, magnitude of braking and the like. Figure 6
It is one Example regarding the acceleration characteristic data in operation data. Assuming characteristics A, B, C, and D for the four types of rotors A, B, C, and D, respectively, the characteristic A is

[0016]

[Equation 1]

This is a case where control is performed by the characteristic of a function (a is a constant). Characteristics B, when the up N _a throw accelerator control from the start, and the rotational speed range above N _a is accelerated at the maximum torque, characteristic C is

[0018]

[Equation 2]

This is an example controlled by the characteristic of a function (c is a constant), and N can be a cubic function of t, a quadratic function or the like, or an exponential function. Characteristic D is a case where constant speed operation is performed at the rotation speed Nb during the time t _D2- t _D1 during acceleration safety up to the rotation speed Ns. FIG. 7 is an example of deceleration characteristic data in the operation data. Similarly to FIG. 6, the rotor E,
When the characteristics E, F, G, and H are determined for F, G, and H, the characteristic E is

[0020]

[Equation 3]

(E is a constant, N ≧ 0). Characteristic F is an example in which slow brake control of deceleration of N _d or less is performed, and characteristic G is

[0022]

[Equation 4]

This is an example of controlling by a function of (a constant of g> 0, and a range of N ≧ 0), and N can be a cube root function, a square root function or the like of t, or an exponential function. Characteristic H is a case where constant speed operation is performed at a rotation speed Nc for a time t _H2 -t _H1 during deceleration until stopping. FIG. 8 shows an example in which the characteristic D of FIG. 6 and the characteristic H of FIG. 7 are combined and further applied.

Here, the rotational speeds N _{1 to} N ₇ during constant speed operation and the time during which the constant speed is maintained t ₂ −t ₁ , t ₄ −t ₃ , t ₆ −
_{t 5, ......, t 14 -t} 13 is assumed to be arbitrarily set. Also, the number of constant speed operations during acceleration up to the maximum speed,
Also, the number of constant speed operations during deceleration from the maximum rotation speed to the stop can be arbitrarily set. Figure 9 is a combination example rotational speed N ₁ or less slow accelerator control characteristics, performs slow brake control, the acceleration by the maximum torque in N ₁ or more,
Although deceleration is a brake with maximum torque up to N ₁ , constant speed operation is performed at the rotation speeds N ₃ and N ₂ during deceleration. FIG. 10 is likewise an example of a combination of characteristics. When the rotational speed changes from N ₃ to N ₄ , it is decelerated and reaches N ₂ and then immediately accelerated to settle to N ₄ , or conversely, the rotational speed N ₄ after immediately decelerate after reaching the N ₅ to accelerate the time of transition to N ₁ mode to settle to N _1, Ichi担is further decelerated from the rotational speed N ₈ N ₆
This is the case where the operation is performed in the mode of accelerating to N ₇ after settling to.

11 and 12 are flowcharts showing the operation of the control circuit 3 at the time of acceleration / deceleration, and FIGS. 13 and 14 are flowcharts showing the operation at the time of constant speed operation during acceleration or deceleration. 11 and 13 show the case of inputting rotor type information via the rotor type setting device 7, and FIGS. 12 and 14 show the case of inputting via the rotor detector 6. Regarding the encoding of the operation data, it is possible not only for each type of rotor but also when there are a plurality of rotors of the same shape to be encoded for each rotor and input to the control circuit 3 as information for each rotor for control. .

[0026]

As described above, according to the present invention, since the optimum operating characteristics can be selected for the rotor to be used without operating mistakes, the operation with good reproducibility, high efficiency, high accuracy, and high safety, Centrifugation may be possible. Further, since the operation data is unique to the rotor used, the rotor acceleration / deceleration time can be optimized.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a drive circuit for a centrifuge according to the present invention.

FIG. 2 is an acceleration characteristic diagram when the electric power supplied to the motor in the conventional centrifuge is maximum.

FIG. 3 is an acceleration characteristic diagram when a rotor is loaded with a density gradient liquid by a conventional centrifuge.

FIG. 4 is a deceleration characteristic diagram when a maximum braking force is applied to a centrifuge in a conventional centrifuge.

FIG. 5 is a deceleration characteristic diagram when moderate braking is applied in a low speed range by a conventional centrifuge.

6 is a characteristic diagram showing an example of the acceleration characteristic of FIG.

7 is a characteristic diagram showing an example of the deceleration characteristic of FIG.

8 is a characteristic diagram showing an example of the acceleration characteristic of FIG. 1. FIG.

FIG. 9 is a characteristic diagram showing an example of the acceleration characteristic of FIG.

10 is a characteristic diagram showing an example of the acceleration characteristic of FIG. 1. FIG.

FIG. 11 is a flowchart showing an operation during acceleration / deceleration of the drive circuit of the centrifuge of the present invention.

FIG. 12 is a flow chart showing an operation during acceleration / deceleration of the drive circuit of the centrifuge of the present invention.

FIG. 13 is a flowchart showing an operation during acceleration / deceleration of the drive circuit of the centrifuge of the present invention.

FIG. 14 is a flowchart showing the operation of the drive circuit of the centrifuge of the present invention during acceleration / deceleration.

FIG. 15 is a diagram showing encoding of operation data in a conventional centrifuge.

FIG. 16 is a diagram showing encoding of operation data of the drive circuit of the centrifuge according to the present invention.

[Explanation of symbols]

1 is a rotor, 2 is a motor, 3 is a control circuit, 4 is a rotation characteristic storage unit, 5 is a rotor discriminating circuit, 6 is a rotor detector, 7 is a rotor type setting device, and 8 is a rotation characteristic setting device.

Claims (2)

[Claims] 1. A centrifuge in which a plurality of types of rotating bodies are exchanged for use, a motor for rotationally driving a rotor, a control circuit for controlling the rotation of the motor, and a type of rotor arbitrarily set by a user. It has means for sending different information to the control circuit, or means for the control circuit to automatically detect the rotor type, and the acceleration and deceleration characteristics up to the number of revolutions required for centrifugation are determined according to the rotor type. A drive circuit of a centrifuge having a function capable of 2. The drive circuit for a centrifuge according to claim 1, further comprising a function capable of inputting an operating parameter that determines the acceleration / deceleration characteristic and a parameter required for centrifugal separation.