JPH1094504A - Vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control abnormal high-speed rotation of a driving motor for a suction fan, while a nozzle is closed. SOLUTION: This vacuum cleaner comprises a driving motor 1 for a suction fan, and the current controlling element TR. A firing pulse is transmitted to the current controlling element TR through a firing angle controlling circuit 5, a complex type three leg transformer 4, and a firing circuit 6, to control a firing phase angle and control energizing current of the motor 1. In this case, a current detecting circuit 7 for detecting input current of the motor 1 is installed the series circuit. And, during full firing, with a nozzle closed, a high- speed rotation restraint circuit 9 detects that the input current of the motor 1 falls to a specified value or under, to shift the firing angle controlling circuit 5, through a power limit controlling circuit 8, from full firing to phase control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum cleaner, and more particularly to a vacuum cleaner for preventing abnormal high-speed rotation when a nozzle is closed.

[0002]

2. Description of the Related Art In recent years, a vacuum cleaner has a motor for rotating a suction fan and a current control element for controlling the on / off of the motor connected in series and connected to an AC power supply. A firing pulse is applied and turned on, and the firing angle of the firing pulse is controlled by a phase control circuit to control the power. In this type of vacuum cleaner, the nozzle opening is detected and the device is limited so that the maximum input does not become the maximum input when the value of the input power indicates the maximum.

[0003]

As described above, when the nozzle is closed, such as when the floor is cleaned with a large input power, as in a conventional vacuum cleaner, the inside of the vacuum cleaner, especially The degree of vacuum in the suction tube increases, and the air resistance of the fan decreases extremely. As a result, the motor rotates at an abnormally high speed. Abnormal high-speed rotation of the motor increases the load on the bearings that support the rotor of the motor, which leads to increased wear, which shortens the life of the bearings and causes adverse vibration and noise. There was a problem.

The present invention has been made in view of the above-mentioned problems, and has as its object to provide an electric vacuum cleaner capable of suppressing abnormal high-speed rotation of a driving motor of a suction fan when a nozzle is closed. I have.

[0005]

A vacuum cleaner according to the present invention provides a motor for rotating a suction fan, a current control element for controlling the energization of the motor, and a firing pulse applied to the current control element. A current detection circuit for detecting an input current of the motor, wherein the current detection circuit detects an input current of the motor, Means for shifting the firing angle control circuit from full firing to phase control when the input current of the motor detected by the circuit becomes equal to or less than a predetermined value.

In this vacuum cleaner, if the nozzle is closed at the time of full ignition, the degree of vacuum in the suction passage increases. As a result, the motor shifts to high-speed rotation, but the input current of the motor decreases with high-speed rotation. When the current detection circuit detects the reduced input current, when the reduced input current becomes equal to or less than a predetermined value, the phase shifts from the full ignition to the phase control, the rotation of the motor is suppressed to a predetermined value, and an abnormal high speed rotation is performed. It is prevented from unfolding.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to embodiments. FIG. 1 is a block diagram showing a schematic configuration of a motor control device of an electric vacuum cleaner according to one embodiment of the present invention. This motor control device comprises a series connection of a motor 1 and a current control element TR, is connected to an AC power supply 2 and, when the current control element TR is turned on, a circuit 10 for energizing the motor 1, a primary coil P, a secondary coil a tripod transformer 4 comprising S ₁ and tertiary coil S _2, is connected to the secondary coil S ₁ of the tripod transformer 4, the firing angle control circuit 5 that generates firing pulses of a predetermined phase angle, the tripod transformer 4
Is connected to the tertiary coil S _2, it receives a fire pulse, the firing circuit 6 that turns on the current control device TR, a current detection circuit 7 for detecting a current flowing through the motor 1, the air volume becomes larger power A power limit control circuit 8 for controlling the motor; and a high circuit suppression circuit 9 for suppressing the high-speed rotation of the motor 1 when the detection current output from the current detection circuit 7 becomes smaller than a predetermined value under full ignition. It has.

In the motor control device of this vacuum cleaner, the ignition pulse generated by the ignition angle control circuit 5 is applied to the tripod transformer 4
Through the secondary coil S ₁ and the tertiary coil S ₂ of the ignition circuit 6
And the current control element TR is turned on to drive the motor 1 for a period corresponding to the phase angle of the firing pulse. When the motor 1 is energized, the current is detected by the current detection circuit 7 and applied to the power limit control circuit 8. The power limit control circuit 8 controls the phase of the firing pulse of the firing angle control circuit 5 according to the detected current value. That is, if the current value is large, the firing angle is increased to reduce the power, The power supply time of the control element TR is reduced, and power supply is leveled.

Further, in the full ignition state, when the nozzle is closed and the air volume is reduced, the motor 1 rotates at a high speed.
When the current detected by the current detection circuit 7 is smaller than a predetermined value, the motor 1 has a characteristic that the current decreases at high speed rotation in a closed state.
, The phase angle of the firing angle control circuit 5 is delayed to make the firing angle a predetermined firing angle from full firing, and the power is reduced to prevent the motor 1 from extremely rotating at a high speed.

The circuits shown in FIGS. 2, 3 and 4 show the respective circuits of the motor control device of the above-described embodiment in a limited manner. In FIG. 2, a primary coil P of a composite or leakage type tripod transformer 4 is connected to AC power supply lines 11 and 12 to which a commercial AC power supply 2 is connected, and a fan motor 1 is connected in parallel with the primary coil P. , A series circuit 10 of a bidirectional three-terminal thyristor TR is connected. Here, however, the primary coil of the current transformer CT of the current detection circuit 7 is further connected between the line 12 and the motor circuit 10.

Diodes D ₁ connected in series with the same polarity,
Diodes D ₃ and D ₄ connected in series with the same polarity as D ₂
When, and these series circuits of diodes connected in parallel so as to be opposite polarities, and one end of the parallel circuit tertiary coil S _2, it is connected to the gate G of the bidirectional three-terminal thyristor TR, the gate G The capacitor C ₃ is connected between the lines 13 to form the ignition circuit 6.

As shown in FIG. 3, the secondary of the tripod transformer 4
Coil S₁Is a diode D_Five, D₆, D₇, D₈
Input terminals a and b of the bridge type rectifier circuit 14 composed of
And the output terminals c and d of the rectifier circuit 14 are
DC power line of the phase control circuit 15 as a power generation circuit
16 and 17 are connected. NPN type of phase control circuit
Transistor Q₁Collector, emitter and zener
Diode ZD1 is connected between DC power supply lines 16 and 17
And the transistor Q₁Is a resistor R_ThreeThrough
PNP type transistor Q_TwoConnected to the collector of
Both resistors R _TwoConnected to the DC power supply line 17
Have been. A resistor R is connected between the DC power supply lines 16 and 17.
_Four, R_FiveAre connected to each other. this
As shown in FIG. 4 between the DC power supply lines 16 and 17
And the resistor R_Fifteen, R₁₆, Variable resistor VR1, capacitor C_Four
Are connected to form a time constant circuit. Rank
Transistor Q constituting phase control circuit 15_TwoBase of
And the resistance R_Four, R_FiveDiode D between the connection points₉Is connected
And the transistor Q_TwoOf the variable resistor VR1
Capacitor C_FourConnected to the connection point.

[0013] As shown in FIG.
A capacitor C is connected to both ends of the secondary coil of the transformer CT.₇And resistance
R₇Series circuit, resistor R₈And variable resistor VR_TwoSeries circuit
Is connected, and the diode D₁₁, D₁₂, ..., D₁₄Or
The rectifier circuit 18 is connected and configured. Power
The limiting control circuit 8 includes a resistor R
₉And the capacitor C₈Connected in parallel.
Resistor R in the parallel circuit of_TenAnd Zener diode ZD _ThreeSeries
Circuits are connected in parallel. Resistance R_TenAnd Zena Daio
Do ZD_ThreeIs a PNP transistor Q_ThreeBee
Transistor Q_ThreeThe emitter is a resistor
R₁₁To the line 16 via the
Jista Q _ThreeIs a PNP transistor Q_Fourof
Connected to the base and the capacitor C₉Through
Connected to line 16 and a resistor R₁₂, Resistance R₆, Die
Aether D_TenIs connected to the line 17 via the. Tiger
Transistor Q_FourOf the same resistance R₆, Diode D
_TenThrough the line 17 and the emitter is connected to the resistor R₁₃Through
PNP type transistor Q_FiveConnected to the base of
You. Transistor Q_FiveOf the resistor R₁₄Through la
While the collector is connected as described above.
And the resistor R₁₆Is connected to the variable resistor VR1 through
You. This transistor Q_FiveAnd resistance R₁₄In the series circuit of
Iod D_Fifteen, Resistance R_FifteenParallel circuits are connected in parallel
I have.

The high rotation suppression circuit 9 includes a transistor Q₆,
Q₇, Q₈And other circuit elements. Ba
Transistor Q for buffer₆Is connected to line 19
And the collector is the capacitor C₆Via line 16
And the emitter is connected to the resistor R₁₇Through la
And a Zener diode ZD_Four,
Resistance R₁₉Through the transistor Q₇Connected to the base of
ing. Transistor Q₆The collector of R
₂₀Through the transistor Q₇The collector of the transistor
Q₈Connected to the base. Also, Zenadaio
Do ZD_FourAnd resistance R₁₉Is a resistor R₁₈Through the line
16 are connected. Transistor Q ₈The emitter is
Connected to line 16 and the collector
Star Q_FiveConnected to the base.

Next, the operation of the circuit of this embodiment will be described. In a state where the AC power source 2 is not connected to the circuit, the voltage on the emitter of the transistor Q ₂ is not applied not turned on, thus, not any voltage is applied to the base of the transistor Q _1, a state of off-the secondary coil S since _one does not short-circuit the voltage is not generated in the tertiary coil S _2. Therefore, no signal is given to the gate G of the bidirectional three-terminal thyristor TR, and no ignition occurs, so that the power supply voltage is not applied to the motor 1.

Here, when the AC power supply 2 is connected,
Through the rectifier circuit 14 and the DC power supply line 1
DC voltage is applied between 6 and 17, and the capacitor C_FourIs
Anti-R_Fifteen, R₁₆, Volume VR₁Is charged through
Transistor Q_TwoThe emitter voltage of the resistor R_Four,
R_FiveTransistor Q applied with partial voltage at_FourOf the base
When the voltage is exceeded, the base current flows and turns on, and the capacitor
C_FourIs charged to the resistor R_Three, R_TwoDischarge through
Then, a pulse is oscillated (b in FIG. 5). Capacitor C _Fourof
Charging and discharging are performed in a half cycle by changing the variable resistor VR1.
It is repeated 1 to 10 several times,
The first cross occurs in synchronization with the power supply frequency. Accordingly
And the resistance R at the cross_TwoThe voltage of the transistor
Q₁Transistor Q applied to the base of₁Turns on,
Secondary coil S via full-wave rectifier 14 ₁The pulse signal
(Fig. 5D). Due to the characteristics of tripod transformer 4
Tertiary coil S_TwoThe pulse signal corresponding to the short circuit.
Signal (E in FIG. 5) is induced, and bidirectional through the ignition circuit 6.
It is applied to the gate G of the three-terminal thyristor TR and fires,
A phase-controlled voltage (f in FIG. 5) is applied to the motor 1.
You. As a result, a current corresponding to the phase angle flows through the motor 1.
You.

Here, when the tip of the nozzle is opened, the
The current flowing through the current detection circuit 7
The secondary voltage of the device CT also becomes large. Therefore, the rectifier circuit
18 also has a large DC output, and the resistance R_TenVoltage across
Is also great. Resistance R_TenWhen the voltage of the transistor increases, the transistor
Q_ThreeThe collector current of the resistor R₁₂Voltage is also large
Transistor Q_FourEmitter voltage also increases. this
Therefore, the transistor Q _FiveIf the base impedance of
This transistor Q_FiveCollector current decreases
You. That is, the resistance is connected to the line 16 of the power limit control circuit 8.
Anti-R₁₆The combined resistance between them becomes large, and the variable resistance VR₁The flow
Current decreases. This means that the phase control circuit 15
Capacitor C_FourMeans that the charging current to
As a result, the transistor Q₁Delay the time to turn on
Delay firing angle. As a result, the current flowing through the motor 1 is reduced.
Decrease power and perform power control.

The variable resistor VR₁Of the resistance at 0
When the floor is tightly closed to the floor etc., the air volume becomes small,
Vacuum, motor 1 rotates at high speed and low input current
Becomes When the input current to the motor 1 becomes small, the current is detected.
The secondary voltage of the current transformer CT of the circuit 7 also becomes small, and the rectifier circuit
18, the current output becomes small, and the resistance R_TenAnd the voltage across
Become. Therefore, the transistor Q_ThreeCollector current
A little resistance R₁₂Also decreases. This allows the tiger
Transistor Q_FourCurrent increases and the emitter voltage decreases.
You. This transistor Q_FourThe emitter voltage of
And transistor Q_FiveBase current and collector current
Great, resistance R_FifteenIs the resistance R₁₄Is short-circuited. So
Therefore, the line 16 and the resistor R₁₆The resistance between
Variable resistance VR ₁The current flowing through the
C_FourThe current flowing through the phase control circuit 15 also becomes large,
It will be in a full firing state.

On the other hand, since the transistor Q ₆ is a buffer, one end of the resistor R ₉ , that is, the voltage V _{R9 of the} line 19,
Voltage V _R17 at the connection point between the emitter of the resistor R ₁₇ and transistor Q ₆ becomes V _R9 ≒ V _R17. As described above, when the output of the current transformer CT decreases in a closed state, VR ₁₇ ≦ V _ZD4 , and
Substantially zero base current of the transistor Q ₇ is, the transistor Q ₇ is turned off. As a result, the transistor Q ₈
Turns on. By on of the transistor Q _8, the base of the transistor Q ₅ is almost the same potential as the line 16, the transistor Q ₅ is turned off. This makes it possible to resistor R ₁₄ which are connected in parallel to the resistor R ₁₅ is disconnected, the resistance becomes large, which is connected to the line 16 and the resistor _16, the current flowing through the variable resistor VR ₁ is small. Thus, the state is shifted from the full ignition state to the phase control state.

[0020]

According to the present invention, when the input current of the motor which detects the input current of the motor for driving the suction fan and the input current of the motor which is detected by the current detection circuit at the time of full ignition becomes lower than a predetermined value, Since the phase control is shifted from full firing, even if the nozzle is closed at full firing and the motor rotates at high speed, the input current of the motor is increased by increasing the degree of vacuum in the suction path due to the nozzle being closed. As the input current decreases, the phase control is started from the full ignition, so that the energization time of the motor is suppressed and the high-speed rotation is also suppressed. By suppressing the high-speed rotation when the nozzle is closed in this way, it is possible to prevent the life of the bearing from being shortened due to the abnormal high-speed rotation of the motor when the nozzle is closed. Also, abnormal vibration and noise caused by abnormal high-speed rotation of the motor when the nozzle is closed can be prevented. Further, there is an effect that the production cost can be reduced by preventing excessive quality of the bearing structure parts, and energy can be saved by reducing unnecessary power consumption when the nozzle is closed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic circuit configuration of a motor control device of an electric vacuum cleaner according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing specific circuits of a motor energizing circuit and a firing circuit which constitute the motor control device.

FIG. 3 is a circuit diagram showing a specific circuit of a firing angle control circuit constituting the motor control device.

FIG. 4 is a circuit diagram showing specific circuits of a current detection circuit, a power limit control circuit, and a high rotation prevention circuit that constitute the motor control device.

FIG. 5 is a waveform diagram for explaining a firing pulse generation operation of the motor control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 4 Composite tripod transformer 5 Firing angle control circuit 6 Firing circuit 7 Current detection circuit 8 Power limit control circuit 9 High rotation suppression circuit TR Current control element

Claims (1)

[Claims] 1. A motor for rotating a suction fan, a current control element for controlling energization of the motor, and a motor which is turned on by applying a firing pulse to the current control element to control a firing angle. A firing angle control circuit that controls a current flowing through the vacuum cleaner, wherein a current detection circuit that detects an input current of the motor, and an input current of the motor that is detected by the current detection circuit during full firing. Means for shifting the firing angle control circuit from full firing to phase control when the firing angle becomes equal to or less than a predetermined value.