JPH0761456B2 - Deceleration control method for rotating equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a deceleration control method for rotating equipment represented by a centrifuge.

[Conventional technology]

In the centrifuge, in order to efficiently centrifuge the sample, the separation time is shortened by accelerating and decelerating the rotor with the maximum torque of the motor.

[Problems to be Solved by the Invention]

However, conventionally, when braking and decelerating a rotating device typified by the above-mentioned centrifuge, if a frequency at which the maximum braking torque is obtained is given to the motor at one time, excessive regenerative power will be generated and the motor will be stable. Therefore, if the problem is solved, the deceleration control of the motor can be stably maintained, and the processing time of various works using the rotating equipment can be controlled. Can be shortened.

The present invention has been made in consideration of the above points,
The object is to provide a rotating device typified by a centrifuge, which can maintain the speed control of the motor in a stable manner and can shorten the processing time of various works by using the rotating device as compared with the conventional one. It is to provide a deceleration control method.

[Means for Solving the Problems]

The above-mentioned object includes a motor that drives a rotating body, a rotation speed detection circuit that detects the rotation speed of the motor, a frequency generation circuit that controls the frequency of the motor, and an arithmetic circuit that calculates the frequency given to the motor from the rotation speed. This is achieved by adding a time counter circuit that counts the time from the start of deceleration of the motor in the device and controlling the output of the arithmetic circuit by the value of this time counter circuit.

[Action]

That is, the present invention pays attention to the fact that the frequency control of the motor for driving the rotating body and the detection of the number of rotations are controlled by the microcomputer, and when the deceleration of the motor is started, it is given to the drive motor by the value of the time counter. By gradually changing the frequency, stable control of the drive motor is performed, and the rotating body can be decelerated for a short time.

〔Example〕

Hereinafter, the present invention will be described with reference to the drawings by taking the case of performing deceleration control of a centrifuge as an example. FIG. 1 is a block circuit machine of a centrifuge suitable for adopting the method of the present invention, and FIG. 2 is a flow chart showing a deceleration control system of the centrifuge shown in FIG.

In FIG. 1 showing a block circuit of a centrifuge, 1 is a power supply, 2 is a forward converter, 3 is an inverse converter, 4 is a motor, 5 is a frequency control circuit, 6 is a rotation speed detection circuit, 7 is a CPU, 8 is R
OM, 9 is RAM, 10 is output interface, 11 is input interface, 12 is memory, 13 is time counter circuit,
14 is an oscillator.

That is, in FIG. 1, a rotating body (not shown) for centrifuging the sample is attached to the motor 4 and rotated.

On the other hand, when stopping the rotating motor 4,
The rotation speed output from the rotation detection circuit 6 is fetched into the CPU 7, and the frequency output to the motor 4 is calculated from the rotation speed. At the start of deceleration, the time counter circuit 13 starts counting, stores the frequency calculated from the number of revolutions in the memory 12 as shown in FIG.
Compare if the value of 13 is N. When the value of the time counter circuit 13 is smaller than N, the time counter circuit 13 concerned
Value / N and the frequency stored in the memory 12 are output to the frequency control circuit 5, and the time counter circuit 13
If the value of N is greater than or equal to N, the frequency of the memory 12 is output to the frequency control circuit 5, and the present invention performs the control at the start of deceleration of the motor to gradually change the frequency, It is possible to prevent an excessive current from flowing to the motor 4.

〔The invention's effect〕

As described above, as is apparent from the description of the illustrated embodiments, according to the present invention, a motor for driving the rotating body, a rotation speed detection circuit for detecting the rotation speed of the motor,
In a rotating device including a frequency generation circuit that controls the frequency of a motor and an arithmetic circuit that calculates the frequency to be applied to the motor from the number of revolutions, a time counter circuit that counts the time from the start of motor deceleration is added By controlling the output of the arithmetic circuit according to the value of the circuit, it is possible to prevent the generation of an excessive current at the start of deceleration, to stably maintain the speed control of the motor, and to use various types of rotary equipment as compared with the conventional one. The work processing time can be shortened.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a block circuit diagram of a centrifuge suitable for adopting the method of the present invention, and FIG. 2 shows a deceleration control system of the centrifuge shown in FIG. It is a flowchart. 1 is a power supply, 2 is a forward converter, 3 is an inverse converter, 4 is a motor,
5 is a frequency control circuit, 6 is a rotation detection circuit, 7 is a CPU, 8
Is ROM, 9 is RAM, 10 is an output interface, 11 is an input interface, 12 is a memory, 13 is a time counter circuit, and 14 is an oscillator.

Claims (1)

[Claims] 1. A motor for driving a rotating body, a rotation speed detection circuit for detecting the rotation speed of the motor, a frequency generation circuit for frequency controlling the motor, and an operation for calculating a frequency given to the motor from the rotation speed. A rotating device having a circuit, wherein a time counter circuit for counting time from the start point of the motor deceleration is added, and the output of the arithmetic circuit is controlled by the value of the time counter circuit. Deceleration control method.