JP2007319581A - Vacuum cleaner control device - Google Patents

Abstract

Electricity for improving the suction performance by optimally controlling the rotation speed of the electric blower without detecting the load current of the electric blower, and for protecting the motor from failure due to overheating, etc. A control device for a vacuum cleaner is provided.
An electric blower equipped with a brushless DC motor, an inverter section for driving the electric blower, PWM drive means for PWM controlling the inverter section, and a rotor magnetic pole position of the brushless DC motor are detected. A magnetic pole position detection means 17 for calculating the rotation speed of the electric blower 2 from the output of the magnetic pole position detection means 17 and controlling the PWM drive means 16 so that the rotation speed of the electric blower 2 is constant. In the inverter-controlled vacuum cleaner, the air flow of the vacuum cleaner is calculated from the duty ratio of the PWM control, and the electric blower 2 is controlled.
[Selection] Figure 2

Description

  The present invention relates to a vacuum cleaner, and more particularly to a control device for a vacuum cleaner that performs inverter control of the operation of a motor.

  Conventionally, in this type of vacuum cleaner, an electric blower including a fan and an AC commutator motor is used as a drive source. However, commutator motors are electrically driven by wear due to mechanical sliding between the brush and the commutator, and recently due to higher suction work rates due to higher fan speeds, or reduced vacuuming and weight reduction. The usage environment of the blower became severe, and the motor life tended to be shortened.

  In recent years, an electric blower using a brushless DC motor has been proposed as a countermeasure. For example, the rotation speed of the brushless DC motor is optimally controlled according to the load fluctuation of the vacuum cleaner, and the suction performance is improved (see, for example, Patent Document 1).

In addition, there are some which perform optimal control by calculating a load state (for example, air volume or static pressure) from the load current and the rotation speed of the motor and adjusting the rotation speed of the motor based on the calculation result. (For example, refer to Patent Document 2).
Japanese Unexamined Patent Publication No. 63-095884 Japanese Patent Laid-Open No. 04-004788

  However, in the control device of the conventional vacuum cleaner, a low constant resistance is used to detect the load current of the electric blower equipped with the brassless DC motor, and the detection is based on the voltage drop of the current flowing through the low constant resistance. It was a thing. However, there is a problem that the low constant resistance has a large variation in a single product and is easily affected by the ambient temperature, so the load current cannot be detected accurately, that is, it is not suitable for fine motor control. It was.

  The present invention solves the above-mentioned conventional problem, and without any load current of the electric blower being detected, the rotation speed of the electric blower is optimally controlled to improve the suction performance, and the failure due to overheating of the motor is also achieved. It aims at providing the control apparatus of the electric blower which aims at the improvement of a motor lifetime by preventing.

  In order to solve the above-described conventional problems, a control device for a vacuum cleaner according to the present invention includes an electric blower equipped with a brushless DC motor, an inverter unit that drives the electric blower, and PWM drive that performs PWM control on the inverter unit. Means, a magnetic pole position detecting means for detecting the rotor magnetic pole position of the brushless DC motor, and calculating the rotational speed of the electric blower from the output of the magnetic pole position detecting means, so that the rotational speed of the electric blower becomes constant. In an inverter-controlled vacuum cleaner provided with control means for controlling PWM drive means, the air volume of the vacuum cleaner is calculated from the duty ratio of PWM control.

  Thus, the rotation speed of the electric blower is optimally controlled according to the calculated air flow of the vacuum cleaner without detecting the load current of the electric blower, and the suction performance is improved.

  The control device for a vacuum cleaner of the present invention can improve the suction performance by optimally controlling the rotation speed of the electric blower, and can improve the motor life.

  A first invention is an electric blower equipped with a brushless DC motor, an inverter unit for driving the electric blower, PWM drive means for PWM control of the inverter unit, and a magnetic pole for detecting a rotor magnetic pole position of the brushless DC motor. Inverter-controlled electricity comprising: a position detection means; and a control means for calculating the rotational speed of the electric blower from the output of the magnetic pole position detection means and controlling the PWM drive means so that the rotational speed of the electric blower is constant. In the vacuum cleaner, by calculating the air volume of the vacuum cleaner from the duty ratio of the PWM control, the rotational speed of the electric blower can be optimally controlled and the suction performance can be improved.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the control is performed so as to increase the rotational speed of the electric blower stepwise in order to maintain the target air volume based on the air volume calculated from the duty ratio of the PWM control. It is possible to maintain a constant air volume and improve the suction performance.

  According to a third aspect of the invention, in particular, in the first or second aspect of the invention, when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting the input down, the rotational speed of the electric blower is reduced. By controlling, it is possible to protect against an overload state of the electric blower from a failure due to overheating of the brushless DC motor.

  In a fourth aspect of the invention, in particular, in the third aspect of the invention, after the rotational speed of the electric blower is lowered, the rotational speed of the electric blower is set when the duty ratio of the PWM control is higher than a preset value for returning the air volume. Suction performance can be improved by controlling the air volume to be raised and restored.

  According to a fifth aspect of the invention, in particular, in the first or second aspect of the invention, when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting the input down, the electric blower is controlled to stop. Thereby, it can protect from the failure by the overheating of the said brushless DC motor with respect to the overload state of an electric blower.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an external perspective view of the electric vacuum cleaner according to the first embodiment of the present invention.

  In FIG. 1, an electric blower 2 equipped with a brushless DC motor (hereinafter referred to as “motor”), which will be described later, is housed in the vacuum cleaner body 1 (hereinafter referred to as “main body”) to generate a suction force. One end of the hose 3 is connected to the air inlet 8 of the main body 1, and the operation unit 4 operated by the user is provided at the other end. A floor nozzle 6 is connected to the other end of the hose 3 via an extension pipe 5. Further, a dust collection chamber 7 in which a dust collection bag is accommodated and a control device 9 for controlling the electric blower 2 are accommodated in the main body 1.

  FIG. 2 is a block diagram showing a first control example of the control device for the vacuum cleaner in the present embodiment, and FIG. 3 is a flowchart for explaining the operation. FIG. 4 is a time chart supplementing the explanation of the operation, and FIG. 5 is a characteristic diagram supplementing the explanation of the operation.

  In FIG. 2, the alternating current of the input alternating current power supply 11 is rectified by the rectifier circuit 12 and converted into a direct current by the smoothing circuit 13. This direct current is supplied to the inverter unit 14 to drive the motor 15. The PWM drive unit 16 performs PWM control of the inverter unit 14, and the magnetic pole position detection unit 17 detects the rotor magnetic pole position of the rotating motor 15. The control means 18 calculates the rotational speed of the motor 15 from the signal of the rotor magnetic pole position detected by the magnetic pole position detection means 17, calculates the parameters of PWM control based on the result, and outputs the signal to the PWM drive means 16. . Here, the parameters of the PWM control are the target rotation speed of the motor 15 and the pulse width of the ON signal for performing the PWM control. The air volume calculating means 19 calculates the air volume of the vacuum cleaner based on the signal from the PWM driving means 16 and the data stored in the air volume characteristic storage means 20 and outputs the result to the control means 18.

  About the control apparatus of the vacuum cleaner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 3, when the user presses the setting switch of the operation unit 4, the motor 15 is activated (step 1), and the cleaner body 1 operates. When the motor 15 rotates, the magnetic pole position detection means 17 detects the rotor magnetic pole position of the motor 15 and outputs it to the control means 18 (step 2). The control means 18 calculates the rotational speed of the motor 15 from the signal from the magnetic pole position detection means 17 (step 3). Further, the control means 18 monitors whether or not the calculated rotational speed is the target rotational speed, obtains the command rotational speed and the ON signal pulse width which are parameters of the PWM control so that the motor 15 becomes the target rotational speed, and performs PWM driving. A signal is output to the means 16 (step 4). The PWM drive means 16 receives this signal and performs PWM control of the inverter unit 14 (step 5) to operate the motor 15.

  On the other hand, the air volume calculating means 19 calculates the air volume that is the load of the vacuum cleaner based on the signal from the PWM driving means 16 and the data stored in the air volume characteristic storage means 20 (step 6). The signal from the PWM drive means 16 is a duty ratio (energization rate) of PWM control obtained from the target command rotational speed and the pulse width of the ON signal.

  Here, as shown in FIG. 4, the duty ratio of the PWM control is a ratio of the pulse width of the ON signal with respect to a predetermined period T, and can be obtained by (Equation 1). For example, when the ON signal pulse width is ½ of the predetermined circumference T, the duty ratio becomes 50%, and when the ON signal pulse width becomes wider, the duty ratio becomes higher (for example, 80%). The duty ratio becomes lower (for example, 20%) when becomes smaller.

  The characteristic diagram of FIG. 5 represents the relationship between the air volume and the duty ratio of the PWM control when the rotation speed of the motor 15 is N [rpm]. According to this, when the motor rotates at a specific rotation speed N, the duty ratio is high when the load of the vacuum cleaner is light and the air volume is large, but the duty ratio is low when the load increases and the air volume decreases. Using this characteristic, the air volume of the vacuum cleaner at a specific rotation speed can be calculated from the duty ratio of PWM control. The air volume characteristic storage means 20 stores data on the relationship between the air volume and the duty ratio for each rotation speed of the motor 15 (for example, operating positions such as strong, medium, and weak) including the characteristics shown in FIG. . The result of the air volume calculated by the air volume calculating means 19 is output to the control means 18, and the control means 18 optimally controls the vacuum cleaner based on the obtained air volume.

  As described above, according to the present embodiment, by calculating the air volume of the vacuum cleaner from the duty ratio of the PWM control, it is possible to optimally control the rotation speed of the electric blower 2 and improve the suction performance. it can.

  FIG. 6 is an operation characteristic diagram illustrating a second control example of the control device for the electric vacuum cleaner according to the present embodiment.

  In FIG. 6, when the electric blower 2 is first operated at the rotational speed N1 (for example, 20,000 rpm) and dust is accumulated in the dust collecting chamber 7, the air volume gradually decreases and the duty ratio of the PWM control decreases. Increase the number to N2 (eg, 30,000 rpm). When the air volume further decreases and the PWM control duty ratio decreases again, the rotational speed is increased to N3 (for example, 40,000 rpm).

  Therefore, by controlling to increase the rotational speed of the electric blower 2 stepwise in order to maintain the target air volume, the constant air volume can be maintained and the suction performance can be improved.

  FIG. 7 is an operation characteristic diagram showing a third control example of the control device for the vacuum cleaner in the present embodiment.

  In FIG. 7, the electric blower 2 is operated at the rotation speed N3 (for example, 40,000 rpm), the air volume gradually decreases, and the air volume calculated from the duty ratio of the PWM control starts from the preset input value. When lowered, the rotational speed is reduced to N1 (for example, 20,000 rpm).

  Therefore, when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting the input down, the electric blower 2 is controlled so as to reduce the rotation speed, thereby preventing the electric blower 2 from being overloaded. Thus, it is possible to protect the motor 15 from failure due to overheating.

  FIG. 8 is an operation characteristic diagram showing a fourth control example of the control device for the electric vacuum cleaner according to the present embodiment.

  In FIG. 8, as shown in the third control example, after the rotational speed of the electric blower 2 is lowered to N1 (for example, 20,000 rpm), the air volume gradually increases, and the PWM control duty ratio is set to the preset air flow rate setting value. When it is further increased, the rotational speed is increased to N3 (for example, 40,000 rpm).

  Therefore, after the rotational speed of the electric blower 2 is lowered, when the duty ratio of the PWM control is higher than a preset value for returning the air volume, control is performed to increase the rotational speed of the electric blower 2 and restore the air volume. The suction performance can be improved.

  FIG. 9 is an operation characteristic diagram illustrating a fifth control example of the control device for the electric vacuum cleaner according to the present embodiment.

  In FIG. 9, when the electric blower 2 is operated at the rotational speed N, the air volume gradually decreases, and when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting input down, the electric blower 2 Stop driving.

  Therefore, when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting the input down, the motor is controlled so as to stop the electric blower 2, so that the motor with respect to the overload state of the electric blower 2 is controlled. It is possible to protect against failure due to 15 overheating.

  As described above, the control device for the electric vacuum cleaner according to the present invention can optimally perform the inverter control of the electric blower according to the use state of the user, and therefore is particularly suitable for the electric vacuum cleaner that performs fine operation control. Useful.

External appearance perspective view of the electric vacuum cleaner in Embodiment 1 of this invention Block diagram showing the first control example Flow chart for explaining the operation of the first control example Time chart supplementing the operation of the first control example Characteristic diagram supplementing the operation of the first control example Operation characteristic diagram showing the second control example Operation characteristic diagram showing the third control example Operation characteristic diagram showing the fourth control example Operation characteristic diagram showing the fifth control example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum cleaner main body 2 Electric blower 3 Hose 4 Operation part 5 Extension pipe 6 Floor nozzle 7 Dust collection chamber 9 Control apparatus 11 Input AC power supply 12 Rectifier circuit 13 Smoothing circuit 14 Inverter part 15 Brushless DC motor 16 PWM drive means 17 Magnetic pole position detection Means 18 Control means 19 Airflow calculation means 20 Airflow characteristic storage means

Claims (5)

An electric blower mounted with a brushless DC motor, an inverter unit for driving the electric blower, a PWM drive unit for PWM control of the inverter unit, a magnetic pole position detection unit for detecting a rotor magnetic pole position of the brushless DC motor, In an inverter-controlled electric vacuum cleaner comprising a control means for calculating the rotational speed of the electric blower from the output of the magnetic pole position detection means and controlling the PWM drive means so that the rotational speed of the electric blower becomes constant, PWM control A control device for a vacuum cleaner, characterized in that the air volume of the vacuum cleaner is calculated from the duty ratio of the vacuum cleaner. 2. The control device for an electric vacuum cleaner according to claim 1, wherein control is performed so as to increase the rotational speed of the electric blower stepwise in order to maintain the target air volume based on the air volume calculated from the duty ratio of PWM control. . The electric vacuum cleaner according to claim 1 or 2, wherein when the air volume calculated from the duty ratio of the PWM control falls below a preset value for starting input down, the electric blower is controlled so as to reduce the rotational speed. Control device. After reducing the rotational speed of the electric blower, when the duty ratio of the PWM control is higher than a preset value for returning the air volume, control is performed to increase the rotational speed of the electric blower and restore the air volume. The control apparatus of the vacuum cleaner of Claim 3. The control of the electric vacuum cleaner according to claim 1 or 2, wherein the electric blower is controlled to stop when the air flow calculated from the duty ratio of the PWM control falls below a preset value for starting the input down. apparatus.