JPH03230787A - Dc brushless motor - Google Patents

Abstract

PURPOSE:To reduce the number of component parts and miniaturize a device by setting a capacitor for working a reset signal creating means after a specified time after making an external power source, and working a braking signal creating means after interrupting the external power source. CONSTITUTION:When a switch 9 is turned ON, then a power source is made in a motor drive controlling IC2. Electric charge is stored in a capacitor 4, and terminal voltage Vs is heightened. The voltage of input provided to a waveform shaping circuit 3 is gradually heightened, and when the voltage exceeds threshold voltage, then reset signal is applied to a reset terminal RST. After that, when the power source from an external section is interrupted, then signal voltage VIN is turned L, and in a motor braking means, braking signal to be turned H is created, and is fed to a FET 6 from an output terminal VC. In this case, as the driving power source of a NOT gate element 5, the electric charge stored in the capacitor 4 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a DC bra sole smoke suitable for downsizing.

(Prior Art) Conventionally, many DC brushless motors, for example, position control motors, have a motor drive control circuit board built into them in order to miniaturize the unit. When the built-in motor is started, the power is turned on from the outside and started, but in order to reset the built-in IC and other electronic components with memory a function and initialize the memory, the reset signal is also activated. This reset signal resets 1c, etc., ensuring normal starting and preventing the motor from running out of control.

Furthermore, if the external power supply is cut off, it is necessary to stop the rotating rotor for safety, and a battery or the like is included for a motor braking means to brake the motor.

[Problems to be Solved by the Invention] However, in the above-mentioned DC brushless motor, since the reset signal at the time of starting is inputted from the outside, reset terminals are provided on each side of the inside and outside of the motor casing, and furthermore, the reset signal is inputted from the outside. Requires lead wire for transmission.

This increases the number of parts and requires a large space.

Furthermore, since a battery is built-in to brake the motor when the power is cut off, there are problems such as the battery life, weight, and the hassle of replacing the battery.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a DC brushless motor that eliminates the above-mentioned problems, reduces the number of parts, achieves miniaturization, and improves convenience in handling.

[Means to solve the problem]

In the DC brushless motor of the present invention, an electronic circuit is installed in the motor casing, and the electronic circuit includes a reset signal generating means for resetting the memory circuit means and generating a cent signal at the time of starting, and a reset signal generating means for resetting the memory circuit means and generating a cent signal when the external power is cut off. and a braking signal generating means for generating a braking signal for activating a motor braking means for braking the rotation. It is characterized by having a capacitor for activating the generating means.

(Function) The DC brushless motor of the present invention has a reset signal generation means in the electronic circuit installed inside the casing, and the reset signal is automatically generated inside the casing.
It does not require an external reset signal input, and when the power is cut off, it automatically generates a braking signal to activate the brake and automatically stops the motor rotation. In addition, the DC planless motor of the present invention realizes the automatic generation and start of these steering signals and braking signals using a single capacitor. That is, when external power is turned on, charging of the capacitor starts at the same time as power is applied to electronic components such as ICs. The potential difference across the capacitor increases in accordance with the integral constant, which has a large influence on the capacitance, and when the terminal voltage of the capacitor exceeds the set voltage, the reset signal generating means is activated to reset electronic components such as ICs. The delay time from power-on to generation of the reset signal is set to a time in which the reset signal works reliably and does not cause malfunctions due to information remaining in the memory of the IC, etc., and is usually 0.1 seconds to 0.1 seconds. It takes about 5 seconds.

Next, when the external power source is cut off, the electric charge accumulated in the capacitor automatically activates the braking signal generating means that operates the circuit for braking the rotation of the motor, and a braking signal is generated.

2, the DC brushless motor of the present invention has a single capacitor that functions as a trigger for generating a reset signal at startup and as a power source for automatically generating a braking signal when the power is cut off.

〔Example〕

FIG. 1 shows a DC brushless motor according to an embodiment of the present invention.
This will be explained with reference to FIG. Figure 1 shows D of this example.
2 is a circuit diagram of a main part of an electronic circuit in a C brushless motor, and FIG. 2 is a timing chart diagram in this embodiment.

In the DC brushless motor of this embodiment, an electronic circuit 1 is installed inside the motor casing, and as shown in FIG. IC2, a waveform shaping circuit 3 which is a reset signal generation means connected to the reset terminal of the motor drive control IC2, a capacitor 4, a NOT gate element 5 which is a braking signal generation means, and an N-type channel FET 6. Diode DI, D2. D3...
, DB, and a resistor 7. An integrating circuit is formed by a capacitor 4 and a resistor 7 connected thereto, and a diode D3.
D4. ..., DB and armature coil 21.22.
23 constitutes the motor braking means 10. An external mold f18 and a switch 9 are provided outside the motor casing.

This DC brushless motor operates as follows.

First, when the switch 9 is turned on, current flows through the electronic circuit 1 in the motor casing, and power is applied to the motor drive control IC 2 via the diode DL. At the same time, a voltage is applied to the capacitor 4 via the diode D2 and the resistor 7.

Charge is accumulated in the capacitor 4 as shown in FIG. 2 according to the integral constant of the integrating circuit formed with the resistor 7, and the terminal voltage Vs thereof increases. The voltage manually applied to the waveform shaping circuit 3 gradually increases and exceeds the dark value voltage vth (at time t
) and a rectangular wave reset signal are the motor drive control IC.
It is applied to the reset terminal R3T of No.2.

In this embodiment, the delay time from when the switch 9 is turned on and the power is turned on until the motor drive control IC 2 is reset is about 0.2 seconds, but this time is determined by ensuring a reliable reset operation and The time is set at a time that can prevent malfunctions due to residual memory, and is greatly influenced by the capacitance of the capacitor 4 and the resistance value of the resistor 7.

Due to the operation of the motor drive control IC 2, an excitation current is conducted to the stator armature coils 21.2:l', 23,
The motor rotates.

In addition, a diode 1) 3 is connected between the output terminal of the motor drive control IC 2 and the armature coil 21, 22, 23.
..., there is a DB, and phase switching is performed.

Next, when the external power supply is cut off, the signal voltage VIN applied to the signal input terminal of the NOT gate element 5
is rl, (Hgh) to rL due to external power cutoff;
(Low), and the motor braking means generates a braking signal that goes from [L, to rH, NOT
The signal is sent from the output terminal Vc of the gate element 5 to the FET 6.

At this time, the charge stored in the capacitor 4 is used as a driving power source for the NOT gate element 5 instead of an external power source. Since the necessary voltage can be supplied to the power input terminal of the NOT gate element 5 for about one second, the above-described operation of the NOT gate element 5 is sufficiently possible.

This braking signal short-circuits the gate and source terminals of the FET 6 and closes the circuit of the motor braking means IO.

As a result, the back electromotive force generated in the stator coil 21 is transmitted from the terminals of the stator coil 21 through the diode D3 to the diode D7. After conducting through D8 and flowing to stator coils 22 and 23, it returns to stator coil 21. Similarly,
The back electromotive force generated in the stator coil 22 is conducted from the terminal of the stator coil 22 through the diode D4, through the diodes D6 and DB, flows to the stator coils 21 and 23, and then returns to the stator coil 22. The back electromotive force generated in the stator coil 23 also flows in the same manner.

In this way, each stator coil 21°22.2
A current due to the back electromotive force generated in step 3 flows from the terminal other than the common terminal of the other phase of the coil toward the common terminal.

As a result, since all three phases are excited simultaneously and in the same direction, this voltage generates an electromagnetic force that brakes the rotation of the motor.

In this way, a short brake is applied to the rotation of the motor.

It should be noted that the present invention is not limited to the above embodiments, but is included within the scope of the present invention as long as it does not depart from the gist of the present invention.

〔Effect of the invention〕

As is clear from the above description, the DC brushless motor of the present invention has a reset signal delay capacitor in the electronic circuit disposed within the motor case. This capacitor is configured to also act as a power source for operating the braking signal generating means for starting the motor braking means when the external power source is cut off.

Therefore, the memory circuit means can be automatically reset after power is applied from an external source, resulting in reliable operation without malfunction, and unlike the external reset method, there is no need for signal lines, terminals, etc., which saves space. You can do it.

Further, the above-mentioned capacitor can also be used as a power source for a means for generating a braking signal that activates a motor braking means for braking the motor when the external power source is cut off, and the accumulated charge is utilized. Therefore, the trouble of replacing batteries, etc., which was necessary in the past, becomes unnecessary, and convenience can be improved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a main part of an electronic circuit of a DC brushless motor according to the present invention, and FIG. 2 is a timing chart in this embodiment. 1... Electronic circuit 2... Motor drive control IC (memory circuit means) 3...
・Waveform shaping circuit (reset signal generation means) 4... Capacitor ・NOT gate element (Se1 movement signal generation means) ・Motor braking means

Claims (1)

[Claims] 1. In a DC brushless motor in which an electronic circuit is installed in the motor casing, the electronic circuit includes a reset signal generating means for generating a reset signal for resetting the memory circuit means at the time of startup, and a reset signal generating means for generating a reset signal for resetting the memory circuit means at the time of startup, and an external power supply cutoff. and a braking signal generating means for generating a braking signal to actuate a motor braking means that brakes the rotation of the motor when the external power is turned on. A DC brushless motor comprising a capacitor for activating a braking signal generating means.