JPS60162491A - Braking device of motor - Google Patents

Abstract

PURPOSE:To stop a motor with good reproducibility in a short time by varying the torque of reverse direction applied to the motor in response to the rotating speed of the motor. CONSTITUTION:A motor is abruptly decelerated at the constant maximum torque capable of being generated by the motor up to the prescribed rotating speed, and thereafter stopped while reducing a brake torque. In this case, a monostable multivibrator 7 is formed to be triggerable, the output pulse width is brought into coincidence with the period of the output frequency of a frequency generator 1 corresponding to the prescribed rotating speed, thereby holding H level (forcible deceleration) for the rotating speed higher than the prescribed speed and varying the ratio of the H level to the L level for the rotating speed lower than the prescribed speed in response to the rotating speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a brake device for a motor of a record player, a compact disc player, or the like.

Conventional configurations and their problems Conventionally, brake devices for motors with small load loss such as record players and compact disc players have used mechanical contacts such as plungers that operate at the same time as the motor stop command, or brake devices that operate at the same time as a motor stop command, or brake devices that operate at the same time as a motor stop command. After setting the motor stop command, at that rotation speed, the maximum deceleration torque is applied to the motor to decelerate the motor, and the electronic circuit detects when the predetermined rotation speed is reached, and decelerates at that point. It was common for brakes to stop and stop braking.

However, regarding the former, there are problems in terms of the price of mechanical parts, reliability1, and noise generated, and regarding the latter, if an error occurs in detecting the rotation speed at which brake torque supply is stopped, for example, the desired If the brake torque supply is stopped at a rotation speed higher than the rotation speed, the motor will not stop easily, and if the brake torque supply does not stop even if the motor rotation speed has reached 0, the motor will not stop. There were serious problems such as reversal. In this conventional method, it is ideal that the motor rotation speed is O when the brake torque supply is stopped, but the frequency generator used to detect the motor rotation speed is usually a magnet, coil, etc. Since the generator consists of several generators, at low frequencies, the output voltage decreases and the detection accuracy decreases (no output is output when the rotation speed is 0), making it impossible to accurately detect the condition, and furthermore, the counter circuit Object of the Invention The object of the present invention is to provide a brake device for a motor that operates stably, that is, to stop the motor in a short time with good reproducibility. Moreover, it is an object of the present invention to provide a brake device for a motor using an electronic circuit that does not cause reverse rotation.

Composition of the Invention The motor braking device of the present invention decelerates a rotating motor by supplying electric power that generates a torque in the opposite direction to the current rotation, and stops the motor when a predetermined rotation speed N is detected. This is a brake device for a motor that stops the supply of electric power to the motor, and is configured to change the torque in the opposite direction applied to the motor by −C depending on the rotational speed of the motor, thereby reducing the power supply for a short time. Furthermore, stable operation without reversing can be ensured.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of essential parts of an embodiment of the present invention.

In Fig. 1, 1 is a frequency generator that generates a frequency signal proportional to the number of rotations of a motor 2, and its output frequency is:
The frequency-voltage conversion circuit 3 converts the voltage into a voltage proportional to the rotation speed of the motor 2.

The output voltage of the frequency-voltage conversion circuit 3 passes through a switch 4 and is even compared with a reference voltage Es of a reference voltage source 6 which is a rotation reference, and the error voltage is amplified by a motor drive circuit 6 to drive the motor 2. . 7 is a monostable multivibrator that generates a constant width noise according to the output signal of the frequency generator 1, and when the switch 4 is on the b side, its output is °゛H''
A forced deceleration command is issued to the motor drive circuit 6 at the H'' level, and when the output is at the "L" level, no command is issued to the motor drive circuit 6, and no power is supplied to the motor 2. The switch 4 is connected to the a side during normal rotation control, and the frequency generator 1, frequency-voltage conversion circuit 3, motor drive circuit 6, and motor 2 form a speed control loop to control the rotation speed corresponding to the reference voltage ES. controlled by.

When a rotation stop command is issued to the motor, switch 4Iib
motor 2 is switched to the side, and the motor 2 is triggered by the output signal of the frequency generator 1 to operate the monostable multi-noise (controlled by the output of the ibrator 7, forced deceleration state, and the pseudo motor rotating only by motor inertia without acceleration or deceleration). The two states of the hold state are repeated alternately, and the rotation rapidly decreases.The time of the forced deceleration state is constant corresponding to the LH' level of the monostable multivibrator, so the output of the frequency generator 1 As the cycle becomes longer, that is, as the rotational speed of the motor 2 decreases, the proportion of time occupied by forced deceleration becomes relatively low, and the brake torque decreases.

Figure 2 (a) is an example of a conventional braking system, in which the brake is applied at point B, the motor is decelerated with the maximum possible torque at point P1, and then the motor is After the power supply is stopped, the motor decelerates due to its own loss (for example, from the shaft side), and reaches time t. This shows a complete stop.

In this case, it is ideal to detect the state of point Po, that is, the rotational speed O, but since the rotational speed is detected, for example, by opening the cycle of the frequency generator attached to the motor,
It is expected that an error of at least one period of the detection period will occur. Therefore, even if you try to stop the forced deceleration by detecting a rotation speed close to 0, the motor rotation speed will decrease due to the error of the one cycle (the rotation speed is close to O, so the time for one cycle is very long). Even when O is reached, deceleration torque is still supplied to the motor, and as a result, the motor rotates in reverse.

In order to eliminate the problems described below, it is necessary to eliminate the error time of one cycle. That is, it is necessary to increase the rotational speed at which the supply of deceleration torque is stopped, but in that case it will take a long time to completely stop.

FIG. 2(b) is a diagram showing the operation when the brake torque is varied according to the rotation speed of the motor 2 in the embodiment of the present invention, that is, when the magnitude of the brake torque is also decreased as the rotation speed decreases. The lower the rotational speed, the smaller the amount of brake torque, and the gradient of rotational deceleration becomes smaller as the rotational speed decreases.

As shown in Fig. 2(b), the detected rotation speed is
) Even if you set the rotation speed N2 much lower than N1 of
Since the gradient of deceleration at the detection point P2 is sufficiently small, even if some detection timing error occurs, a situation where the vehicle decelerates too far and reverses does not occur. In other words, at low rotations where the error in the detection timing of the rotation speed becomes large, the slope of deceleration becomes gentler and the effect of the error is reduced, so that the motor 2 cannot be completely stopped. The time t1 becomes much more than t,'',l(.

b, not shown in FIG. 3, is a graph explaining the operation of the second embodiment of the present invention, which is a further improvement of the method described in FIG. 2(b). The operation after N3 is as shown in Figure 2 (b).
), the brake torque is reduced to bring the vehicle to a stop. In this case, by setting the monostable multivibrator 7 in a triggerable configuration and making the output pulse width of C1 match the period of the output frequency of the frequency generator 1 corresponding to the rotation speed N3, the '° level (forced deceleration) υ呆n1. - For rotational speeds lower than N3, the ratio of the ゛°Mpa level to the °L'-level of X=1 can be configured to change in accordance with the rotational speed.

Fig. 3 a&'': This is an example of the operation of the first embodiment, and since the brake torque is already reduced from the brake command point B in accordance with the motor rotation speed, it takes a long time until the motor stops. It shows.

Effects of the Invention As is clear from the above explanation, the motor braking device of the present invention does not require a mechanical brake, which has many problems in terms of reliability and cost, and can operate stably and reproducibly in a short time. It has the excellent effect of stopping at a certain angle and not causing phenomena such as reversal.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of main parts showing the configuration of a motor braking device according to an embodiment of the present invention, and FIG. 2(a) is a block diagram of main parts. (b) is a characteristic diagram for explaining the operation of the conventional example and the embodiment of the present invention, respectively, and FIG. 3 is a characteristic diagram for explaining the operation of the second embodiment of the present invention. . 1 Frequency generator, 2 Motor, 3 Frequency-voltage conversion circuit, 4 - switch, 6- Motor drive circuit, 7
Monostable multi-novel generator. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 1 Figure 3

Claims (1)

[Claims] (1) The rotating motor is decelerated by supplying electric power that generates torque in the opposite direction to the current rotation, and the specified rotation speed N is reached.
A brake device for a motor that stops supplying electric power to the motor when detecting the motor, and is configured to vary the torque in the opposite direction applied to the motor in accordance with the rotation speed of the motor. Brake device 6 for a motor characterized by (2) a predetermined rotation speed M (however, M ) N
) is detected, a constant reverse torque is applied to the motor, and thereafter, until a rotation speed N is detected, a reverse torque corresponding to the rotation speed is applied to the motor. A braking device for a motor according to claim (1).