JP2001339974A - Permanent magnet field type DC motor control device and vacuum cleaner - Google Patents

Abstract

[PROBLEMS] To provide an inexpensive and highly efficient control device for a permanent magnet field type DC motor. SOLUTION: A field magnet fixed inside a stator core so as to face each other, a rotor provided inside the field magnet and having an armature winding between slots, and an armature winding A permanent magnet field type DC motor having a commutator connected to the commutator and a brush for supplying power while being in contact with the commutator. Rectifying means for supplying, switch means connected in series with the permanent magnet field type DC motor, voltage detecting means for detecting the voltage of the power supply generated by the rectifying means, and a switch in accordance with the value detected by the voltage detecting means Control means for controlling the power supplied to the permanent magnet field type DC motor by controlling the means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC motor control device using a permanent magnet on the field side.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram of a conventional control device for a permanent magnet field type DC motor. In the figure, 1 is an AC power supply, 2 is a diode bridge which is a full-wave rectifier circuit, 3 is a smoothing capacitor for smoothing a voltage which has been full-wave rectified by the diode bridge 2, and 4 is a permanent magnet field type DC motor (hereinafter referred to as a DC motor). , DC motor), 6 is a switch means M
OS-FETs 7 are control means for controlling the switching of the MOS-FET 6, and 5 is a diode connected in parallel with the DC motor 4.

FIG. 9 is an operation timing chart of a conventional DC motor control device, in which a drive power supply voltage (hereinafter, bus voltage) smoothed by full-wave rectification, an operation voltage of control means, and a voltage applied to the DC motor. 5 shows the operation timing of the equivalent voltage.

Next, the operation will be described. The AC power supply 1 is full-wave rectified by a diode bridge 2, and the full-wave rectified voltage is further smoothed by a smoothing capacitor 3 to generate a bus voltage as a drive power supply for the DC motor 4. A MOS-FE connected in series with the DC motor 4
By switching T6 by the control means 7, the applied voltage is controlled to control the rotation speed of the DC motor 4.

Further, since the DC motor 4 is an inductive load, the DC motor 4 tries to keep the current flowing even when the MOS-FET 6 is turned off. 4 can be kept flowing.

[0006]

Since the conventional permanent magnet field type DC motor control device is configured as described above, it has the following problems. If the capacity of the smoothing capacitor 3 is small, the bus voltage becomes a pulsating voltage as shown in FIG. 9, so that the equivalent voltage applied to the DC motor 4 also pulsates. As a result, there is a problem that the current flowing in the DC motor 4 also pulsates, the loss of the motor increases, and the life of the brush used in the DC motor 4 is shortened.

Further, if the capacitance of the smoothing capacitor 3 is increased, the pulsation of the bus voltage can be reduced, but there is a problem that the control device becomes large and the cost of the device increases.

An object of the present invention is to provide a control device for a permanent magnet field type DC motor which is inexpensive and highly efficient.

[0009]

A control device for a permanent magnet field type DC motor according to the present invention includes a field magnet fixed inside a stator core to face each other, and a field magnet fixed inside the field magnet. A permanent magnet field type DC having a rotor provided with an armature winding between slots, a commutator connected to the armature winding, and a brush for supplying power while contacting the commutator. In a motor, a rectifier for supplying a power obtained by rectifying an AC power by a rectifier circuit to a permanent magnet field type DC motor, a switch connected in series with the permanent magnet field type DC motor, and a power source generated by the rectifier. And voltage control means for controlling the power supplied to the permanent magnet field type DC motor by controlling the switch means according to the value detected by the voltage detection means. so That.

In addition, a value detected by the voltage detecting means,
The control means controls the switching means so that the product of the switching means and the on / off ratio of the control means is substantially constant.

Further, a known resistor is used for the voltage detecting means.

A field magnet fixed inside the stator core so as to face each other, a rotor provided inside the field magnet and having an armature winding between the slots, A permanent magnet field type DC motor comprising: a commutator connected to a wire; and a brush for supplying power while being in contact with the commutator. Rectifying means, a switch means connected in series with the permanent magnet field type DC motor, a current detecting means for detecting a current flowing through the permanent magnet field type DC motor, and a value detected by the current detecting means. Control means for controlling the power supplied to the permanent magnet field type DC motor by controlling the switch means in accordance with a predetermined capability of the permanent magnet field type DC motor.

[0013] Further, there is provided control means for controlling the switch means so that the value detected by the current detection means becomes substantially constant.

Further, a known resistor is used for the current detecting means.

Further, when the value detected by the current detecting means exceeds a preset value, control is performed so as to reduce the voltage value of the power supply supplied to the permanent magnet field type DC motor.

Further, when the permanent magnet field type DC motor is started, control is performed so that the ON ratio is gradually increased until the switching ON / OFF ratio of the control means reaches a preset value. .

Further, MOS-FE is used as the switch means.
T is used.

[0018] The vacuum cleaner according to the present invention is characterized in that:
According to a ninth aspect of the present invention, there is provided a control device for a permanent magnet field type DC motor.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are diagrams showing Embodiment 1, FIG. 1 is a configuration diagram of a control device of a permanent magnet field type DC motor, and FIG. 2 is an operation timing diagram of a control device of a permanent magnet field type DC motor. . In FIG.
1 is an AC power supply, 2 is a diode bridge which is a full-wave rectifier circuit, 3 is a smoothing capacitor for smoothing the power rectified by the diode bridge 2, 4 is a DC motor, 5 is a diode connected in parallel with the DC motor 4, 6 Is a MOS-FET which is a switch means, 8 is a voltage detecting means for detecting a bus voltage which is a voltage between both ends of the smoothing capacitor 3, and 7 is a control means which controls switching of the MOS-FET 6 according to the voltage detecting means 8. .

A DC motor 4, which is a permanent magnet field type DC motor, comprises a field magnet fixed inside a stator core so as to face each other, and an armature provided between the field magnet and a slot. It has a rotor with windings, a commutator connected to the armature winding, and a brush for supplying power while contacting the commutator.

FIG. 2 shows the operation timing of the bus voltage, the operating voltage of the control means, and the equivalent voltage applied to the DC motor.

Next, the operation will be described. If the capacity of the smoothing capacitor 3 is small, the bus voltage becomes a pulsating voltage as shown in FIG. The bus voltage is instantaneously detected by the voltage detecting means 8, and the detected result is input to the control means 7. The control means 7 changes the switching ON / OFF ratio (hereinafter, ON-DUTY) in accordance with the detected value, and
The FET 6 is controlled. ON-DU when bus voltage is high
TY is reduced, and when the bus voltage is low, ON-DUTY
, That is, the bus voltage and the ON-DUTY
And the product is controlled to be constant.

As a result, the equivalent voltage applied to the DC motor 4 becomes substantially constant as shown in FIG. DC motor 4
If the voltage applied to the DC motor becomes constant, the flowing current becomes substantially constant, so that the loss of the motor can be reduced and a highly efficient DC motor control device can be obtained.

Further, the rectifying characteristics of the brush used in the DC motor 4 are improved, sparks can be suppressed, and a DC motor control device having a long life and high reliability can be obtained.

Further, since the DC motor 4 has no stator winding, the motor can be easily disassembled when the motor is discarded, and the effect of improving recyclability is obtained.

In this case, a MOS means is used as the switch means.
-Although the description has been given of the case using the FET 6, the same effect can be obtained by using other switch means, for example, a transistor or an IGBT.

Although a full-wave rectifier circuit is described here as a rectifier circuit, similar effects can be obtained by using a voltage doubler rectifier circuit or a half-wave rectifier circuit.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 shows the second embodiment and is a configuration diagram of a control device for a permanent magnet field type DC motor. In the second embodiment, a known resistor is used as the voltage detecting means 8 of the control device shown in the first embodiment. In FIG. 3, the same or corresponding portions as those in FIG. 1 shown in Embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted.

The bus voltage, which is the voltage between both ends of the smoothing capacitor 3, is divided using the two resistors 9 and 10, and the divided value is input to the control means 7. The control means 7 controls the ON-DUTY of the switching of the MOS-FET 6 in accordance with the divided voltage value, so that the equivalent applied voltage to the DC motor 4 becomes substantially constant, so that a substantially constant current can flow and high efficiency can be obtained. A control device for a DC motor can be obtained.

As described above, an inexpensive control device for a DC motor can be obtained by detecting a bus voltage using an inexpensive resistor. In addition, since the control can be performed as described above even if there is a pulsation in the bus bar pressure, the capacity of the smoothing capacitor can be reduced, and a small and inexpensive control device can be obtained.

Embodiment 3 Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 4 shows the third embodiment, and is a configuration diagram of a control device of a permanent magnet field type DC motor. In FIG. 4, FIG.
The same or corresponding parts are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 11 denotes a current detection unit that detects a current flowing through the DC motor 4.

Next, the operation will be described. As mentioned above,
If the capacity of the smoothing capacitor 3 is small, the bus voltage becomes a pulsating voltage. The current flowing through the DC motor 4 is detected by the current detecting means 11, and the detection result is input to the control means 7. The control means 7 controls the MOS-FET 6 by changing the ON-DUTY so that the detected value becomes substantially constant.

When the current flowing through the DC motor 4 becomes substantially constant, the loss of the motor can be reduced, and a highly reliable DC motor control device that suppresses heat generation of the motor can be obtained. Furthermore, since the circuit current of the control device is also reduced, a highly efficient DC motor control device with reduced circuit loss can be obtained.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows the fourth embodiment, and is a configuration diagram of a control device for a permanent magnet field type DC motor. Current detecting means 1 of control device shown in Embodiment 3.
1 uses a known resistor 12. In FIG. 5, the same or corresponding parts as those in FIG. 4 shown in the third embodiment are denoted by the same reference numerals, and description thereof will be omitted.

When the known resistor 12 is used, the voltage generated at both ends of the resistor 12 changes according to the value of the flowing current. For example, if a current of 10 A flows through a 0.1Ω resistor, the generated voltage is 0.1 × 10 = 1 V, and the voltage value changes in proportion to the flowing current. Therefore, it becomes possible to detect the flowing current by detecting the voltage at both ends. If the MOS-FET 6 is controlled by the control means 7 so that the detected value becomes substantially constant, the current flowing through the DC motor 4 becomes constant, and the loss of the motor can be reduced.

As described above, the current flowing in the DC motor 4 can be detected using inexpensive elements, and a small and inexpensive DC motor control device can be obtained.

Embodiment 5 Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 6 shows the fifth embodiment, and is an operation timing chart of the control device of the permanent magnet field type DC motor, showing the operation timing of the current flowing in the DC motor. The value detected by the current detecting means 11 is a current value A1 when the DC motor 4 has a predetermined capacity.
However, an excessive current may flow through the DC motor 4 due to a sudden load change, for example, a shaft lock of the rotor. Here, if the value detected by the current detecting means 11 exceeds a preset current value A2,
The control means 7 sets the MO so that the ON-DUTY is reduced.
The voltage applied to the DC motor 4 is reduced by controlling the S-FET 6.

Here, by setting the set value A2 to a value having a sufficient margin with respect to the current value A3 at which the control device is destroyed, it is possible to reliably prevent an excessive current from flowing through the control device. Destruction of the device can be reliably prevented. Also, since an excessive current can be prevented for the DC motor 4, the demagnetization of the permanent magnet used in the DC motor 4 can be prevented, and the performance of the DC motor 4 can be prevented from deteriorating.

As described above, since an excessive current to the DC motor and the control device can be prevented, a highly reliable DC motor control device can be obtained.

Embodiment 6 FIG. Hereinafter, a sixth embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a diagram showing the sixth embodiment, and is an operation timing chart of the control device of the permanent magnet field type DC motor.
The operation timing of DUTY is shown.

When the DC motor 4 is started while the ON-DUTY is large, the DC motor 4
The current flowing through the DC motor 4 may increase to cause the destruction of the control device. However, the control device according to the present embodiment suppresses the current flowing to the DC motor 4 at the time of startup, and reliably prevents the destruction of the control device. Thus, a highly reliable DC motor control device can be obtained.

Also, since an excessive current can be prevented for the DC motor 4, it is possible to obtain a highly reliable DC motor control device in which permanent magnets are prevented from being demagnetized.

When this control device is mounted on a vacuum cleaner, a high-efficiency control device for the blower motor can be obtained, so that the work efficiency of the vacuum cleaner is increased, and a high-performance vacuum cleaner having a high suction power is obtained. Can be obtained.

Further, since the rectifying characteristics of the brush used for the electric motor are improved and the life of the brush is extended, a highly durable vacuum cleaner can be obtained.

[0045]

The control device for a permanent magnet field type DC motor according to the present invention controls the switch means in accordance with the value detected by the voltage detection means to supply power to the permanent magnet field type DC motor. , A highly efficient permanent magnet field type DC motor control device can be obtained.

Further, the value detected by the voltage detecting means is:
By controlling the product of the control means for controlling the switch means and the on / off ratio of the switching to be substantially constant, it is possible to obtain a control device for a permanent magnet field type DC motor having a long life.

Further, by using a known resistor for the voltage detecting means, it is possible to obtain a small permanent magnet field type DC motor control device.

Further, the power supplied to the permanent magnet field type DC motor is controlled by controlling the switch means according to the value detected by the current detecting means and the predetermined capability of the permanent magnet field type DC motor. Thus, a highly reliable permanent magnet field type DC motor control device that suppresses heat generation of the motor can be obtained.

Also, a high efficiency permanent magnet field type DC motor with reduced circuit loss of the control device is provided by providing control means for controlling the switch means so that the value detected by the current detection means becomes substantially constant. Can be obtained.

Further, by using a known resistor for the current detecting means, an inexpensive control device for a permanent magnet field type DC motor can be obtained.

When the value detected by the current detecting means exceeds a preset value, the voltage value of the power supply supplied to the permanent magnet field type DC motor is controlled to be small, so that the control device is controlled. And a highly reliable permanent magnet field type DC motor control device which prevents the excessive current from being generated.

When the permanent magnet field type DC motor is started, the on / off ratio of the switching of the control means is controlled so as to gradually increase until the on / off ratio becomes a preset value. A highly reliable permanent magnet field type DC motor control device that prevents demagnetization of the permanent magnet can be obtained.

The electric vacuum cleaner according to the present invention has the following features.
By providing the control device for a permanent magnet field type DC motor according to any one of the ninth aspects, a vacuum cleaner having a high attraction force and a high durability can be obtained.

[Brief description of the drawings]

FIG. 1 shows the first embodiment, and is a configuration diagram of a control device of a permanent magnet field type DC motor.

FIG. 2 shows the first embodiment, and is an operation timing chart of the control device of the permanent magnet field type DC motor.

FIG. 3 is a view showing a second embodiment, and is a configuration diagram of a control device of a permanent magnet field type DC motor.

FIG. 4 is a view showing a third embodiment, and is a configuration diagram of a control device of a permanent magnet field type DC motor.

FIG. 5 shows the fourth embodiment and is a configuration diagram of a control device for a permanent magnet field type DC motor.

FIG. 6 shows the fifth embodiment and is a configuration diagram of a control device of a permanent magnet field type DC motor.

FIG. 7 shows the sixth embodiment and is an operation timing chart of the control device for the permanent magnet field type DC motor.

FIG. 8 is a configuration diagram of a conventional control device for a permanent magnet field type DC motor.

FIG. 9 is an operation timing chart of a control device of a conventional permanent magnet field type DC motor.

[Explanation of symbols]

1 AC power supply, 2 diode bridge, 3 smoothing capacitor, 4 permanent magnet field type DC motor, 5 diode, 6 MOS-FET, 7 control means, 8 voltage detection means, 11 current detection means, 9, 10, 12 resistance.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hitoshi Kawaguchi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Yuji Takahashi 1728-1 Koeda, Hanazono-cho, Osato-gun, Saitama Mitsubishi Electric In Home Equipment Co., Ltd. (72) Inventor Akihiro Iwahara 1728-1 Komaeda, Hanazono-cho, Osato-gun, Saitama F-term in Mitsubishi Electric Home Equipment Co., Ltd. 3B006 FA01 3B057 DA01 5H571 AA20 CC05 GG04 GG05 HA09 HB01 HC02 HD02 HD04 LL22 LL23

Claims (10)

[Claims] 1. A field magnet fixed inside a stator core so as to face each other, a rotor provided inside the field magnet and having an armature winding between slots, and In a permanent magnet field type DC motor having a commutator connected to a winding and a brush for supplying power while being in contact with the commutator, a power source obtained by rectifying an AC power supply with a rectifier circuit is a permanent magnet field type. Rectifying means for supplying to the DC motor; switch means connected in series with the permanent magnet field type DC motor; voltage detecting means for detecting a voltage of a power supply generated by the rectifying means; detection by the voltage detecting means Control means for controlling the power supplied to the permanent magnet field type DC motor by controlling the switch means according to the set value. Control device. 2. A value detected by the voltage detecting means,
2. The control device for a permanent magnet field type DC motor according to claim 1, wherein a control is performed such that a product of a switching on / off ratio of said control means for controlling said switch means is substantially constant. 3. A control device for a permanent magnet field type DC motor according to claim 1, wherein a known resistor is used for said voltage detecting means. 4. A field magnet fixed inside the stator core so as to face each other, a rotor provided inside the field magnet and having an armature winding between slots, and the armature In a permanent magnet field type DC motor having a commutator connected to a winding and a brush for supplying power while being in contact with the commutator, a power source obtained by rectifying an AC power supply with a rectifier circuit is a permanent magnet field type. Rectifying means for supplying to the DC motor; switch means connected in series with the permanent magnet field type DC motor; current detecting means for detecting current flowing in the permanent magnet field type DC motor; and the current detecting means Control means for controlling the power supplied to the permanent magnet field type DC motor by controlling the switch means in accordance with the value detected by the above and a predetermined capability of the permanent magnet field type DC motor. Controller for a permanent magnet field type DC motor, characterized in that the. 5. The permanent magnet field type DC motor according to claim 4, further comprising: said control means for controlling said switch means so that a value detected by said current detection means becomes substantially constant. Control device. 6. The control device for a permanent magnet field type DC motor according to claim 4, wherein a known resistor is used for said current detecting means. 7. When the value detected by the current detection means exceeds a preset value, control is performed so as to reduce the voltage value of a power supply supplied to the permanent magnet field type DC motor. The control device for a permanent magnet field type DC motor according to claim 4. 8. When the permanent magnet field type DC motor is started, control is performed such that the ON ratio is gradually increased until the switching ON / OFF ratio of the control means reaches a preset value. The control device for a permanent magnet field type DC motor according to claim 1 or 4, wherein: 9. A MOS-FE as said switch means.
5. The control device for a permanent magnet field type DC motor according to claim 1, wherein T is used. 10. A vacuum cleaner comprising the control device for a permanent magnet field type DC motor according to claim 1. Description: