JP2003310508A - Vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum cleaner in which a motor for suction speedily reaches a target rotating speed even when an environmental temperature is low. <P>SOLUTION: The vacuum cleaner is provided with an operation control means 30 for capturing an operating signal for specifying an input power of a motor 12 for suction based upon operation of a hand switch part 24, a step input control means 32 for outputting a phase angle value changed step by step at the interval of a prescribed time from a prescribed phase angle value to a phase angle value corresponding to the input power specified by the operating signal when starting the motor 12 for suction, and a phase angle control means 38 for controlling the motor for suction based upon the phase angle value from the step input control means 32. The step input control means 32 is set with two kinds of prescribed times (T1 and T2) and switches the prescribed time from T1 to T2 between the prescribed phase angle value and the phase angle value corresponding to the input power specified by the operating signal. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vacuum cleaner that performs a slow start control of a suction motor at startup.

[0002]

2. Description of the Related Art Conventionally, in an electric vacuum cleaner of this type, when a maximum input value (for example, a strong mode) is selected by operating means, the maximum input value is directly changed from a state where the suction motor is stopped. When selected, a large inrush current (rush current) flows and a large voltage fluctuation occurs. This rush current increases as the level of the maximum input value increases. When such a large rush current flows, the voltage of the power supply that supplies power to the suction motor decreases, and the voltage of other electric devices that receive power from the same power supply also decreases. As a result, the operation of this other electric device may become unstable. The operation of the other electric devices becomes more unstable as the voltage drop becomes larger. However, in the worst case, the electric devices including a microcomputer that performs a control operation are in an uncontrollable state, that is, the operation of the microcomputer. The program may not operate normally. Along with this, the load amount of the main control element such as the bidirectional thyristor that controls the suction motor was also increased when the suction motor was started.

Therefore, in order to reduce the rush current at startup, when the maximum input value is selected while the suction motor is stopped, the input power of the suction motor is gradually increased from 0 to the maximum value. Electric vacuum cleaners that incorporate a slow start mechanism have been developed. As an electric vacuum cleaner having a slow start mechanism as described above, for example, in Japanese Patent No. 2804589, when input power is selected by the operating means, steps are taken from the lowest input value to the selected input power at regular intervals. An electric vacuum cleaner has been proposed in which the input power is increased.

[0004]

In the electric vacuum cleaner proposed in the above-mentioned patent publication, the input power is increased stepwise by a fixed time, and the above-mentioned electric power is increased when the suction motor is started. Although the problem has been solved, there is a problem that the suction motor reaches a target rotation speed at a low temperature for a longer time than at a normal temperature.

FIG. 5 is a characteristic diagram showing the relationship between temperature and air density, and uses atmospheric pressure as a parameter. It can be seen from the characteristics of FIG. 5 that the air density increases as the temperature decreases. When the air density increases (at low temperature), the air resistance of the suction motor increases, and it takes longer for the suction motor to reach the target rotation speed than when the air density is low (at high temperature).

FIGS. 6A and 6B show the starting characteristics of the suction motor when the environmental temperature is 20 ° C. and 0 ° C. When the ambient temperature is 0 ° C (low temperature), the suction motor has 3000 times more than when the ambient temperature is 20 ° C.
It takes a long time to reach 0 rpm.

The present invention has been made in order to solve such a problem, so that the suction motor can quickly reach the target rotation speed even when the environmental temperature is low. The purpose of the present invention is to provide a vacuum cleaner.

[0008]

(1) An electric vacuum cleaner according to the present invention includes an operation control means for taking in an operation signal for defining an input power of a suction motor based on an operation of an operation part, and a suction means. Step input control means for outputting a phase angle value stepwise changed every predetermined time from a predetermined phase angle value to a phase angle value corresponding to an input power specified by an operation signal when the motor is started, and a step. In the vacuum cleaner provided with the phase angle control means for controlling the suction motor based on the phase angle value from the input control means, in the step input control means, a plurality of predetermined times are set, and the predetermined phase angle value and , A predetermined time is switched between the phase angle value corresponding to the input power defined by the operation signal.

(2) In the above (1), the first predetermined time T1 before switching and the second predetermined time T after switching
2 is T1 <T2.

(3) In the above (1), the first predetermined time T1 before switching and the second predetermined time T after switching
2 is T1> T2.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a circuit configuration diagram of an electric vacuum cleaner according to Embodiment 1 of the present invention. In the figure, 10 is a commercial power source, 12 is a suction motor, and 14 is a bidirectional thyristor, which are connected in series. The suction motor 12 is provided in the rear part of the dust collecting chamber (not shown) provided in the cleaner body. Reference numeral 16 is a power supply synchronization detection means, which detects the synchronization (zero cross point) of the commercial power supply 10. Reference numeral 18 denotes a current detecting means having a current sensor, which detects a current flowing through the suction motor 12, that is, a drive current. Reference numeral 20 is a microcomputer, and 22 is a non-volatile memory, which stores various data necessary for the arithmetic processing of the microcomputer 20. Reference numeral 24 denotes a hand switch unit, which is provided, for example, at a hand unit (not shown) of the hose, and which has push buttons for selecting input power such as “strong mode” and “weak mode”, and operation of the suction motor 12 Includes a "off" push button to stop the. 26
Is a display unit, for example, the operating state of the suction motor 12 (“strong mode”, “weak mode”) and the like are displayed.

The microcomputer 20 includes an operation control means 30, a step input control means 32, and a phase angle calculation means 3.
6 and each function of the phase control means 38. When the operation control unit 30 receives the operation signal from the hand switch unit 24, the operation control unit 30 outputs the operation signal to the step input control unit 32 and the phase angle calculation unit 36. When the suction motor 12 is started, the step input control means 32 reads various data stored in the ROM 34, and based on a predetermined phase angle value, a phase corresponding to the input power corresponding to the operation signal of the hand switch unit 24. Change the angle step by step,
It is output to the phase control means 38. Also, the phase angle calculation means 3
6 uses the data stored in the non-volatile memory 22 to obtain the phase angle value by a predetermined calculation process (details will be described later) so that the input power value corresponds to the operation signal of the hand switch unit 24. And outputs it to the phase control means 38. The phase control means 38 uses the power supply synchronization signal from the power supply synchronization detection means 16, the step input control means 32 or the phase angle calculation means 3.
A drive pulse signal is generated based on the phase angle value input from 6 to drive the bidirectional thyristor 14.

FIG. 2 is a flowchart showing the processing steps when the microcomputer 20 of FIG. 1 is activated. When a power plug (not shown) is connected to the outlet,
A closed circuit composed of the commercial power source 10, the suction motor 12, and the bidirectional thyristor 14 is formed, and a driving voltage is applied to the microcomputer 20 to enter an operating state (S101). The step input control means 32 reads out and sets the initial phase value at the time of starting the motor from the built-in ROM 34, for example (S102), and sets the predetermined time (T1) before the switching point (S103). The step input control means 32 reads out the target phase angle value corresponding to the operation signal from the operation control means 30 from the ROM 33 and sets it (S104). The target phase angle value corresponding to this operation signal is the phase angle value of the drive pulse signal of the bidirectional thyristor 14 corresponding to those modes when the operation signal is, for example, strong mode operation or weak mode operation. The step input control means 32 calculates the phase angle value of the switching point (S105). The calculation of the phase angle value of the switching point is obtained as the target phase angle value + the added phase angle value = the phase angle value of the switching point. The added phase angle value is set to an appropriate value by experience. The step input control means 32 reads out and sets a predetermined time (T2, T2> T1) after the switching point from the ROM 33 (S106).

When the setting process of the step input control means 32 after the power is turned on is completed as described above, the operation control means 30 takes in the operation signal of the hand switch section 24 (S
107), based on the presence or absence of the operation signal (strong mode or weak mode), it is determined whether or not the suction motor 12 is being driven (S108). If you're not driving yet,
The operation control unit 30 waits until the switch (strong mode or weak mode) of the hand switch unit 24 is turned on (S109). When the switch of the hand switch unit 24 (strong mode or weak mode) is turned on, the step input control means 32 outputs the initial phase angle value at the time of starting the motor, which was set at the initial stage, to the phase control means 38 ( S1
10). The phase control means 38 is the step input control means 3
When the initial phase angle value from 2 is input, the drive pulse signal corresponding to the phase angle value is generated to generate the bidirectional thyristor 14
Supply to. The bidirectional thyristor 14 operates according to the drive pulse signal, the drive voltage is supplied to the suction motor 12, and the suction motor 12 starts to rotate.

The operation control means 30 operates in the same manner as above.
The operation signal of the hand switch unit 24 is fetched (S10
7) Based on the presence / absence of an operation signal (strong mode or weak mode), it is determined whether or not the suction motor 12 is being driven (S108), but here it can be confirmed that it is already being driven. Since this is possible, the process moves to the next step.

The operation control means 30 includes a hand switch section 24.
Of the switch (strong mode or weak mode) is turned on (S111), and if not turned on, the step input control means 32 performs a motor starting process up to the switching point (S113). . That is, the step input control means 32 subtracts a predetermined phase angle value for each predetermined time (T1) from the initial phase angle value at the time of starting the motor and outputs it to the phase control means 38. The process is repeated until the phase angle value reaches the switching point (S113). After the phase angle value reaches the switching point, the step input control means 32 performs the motor starting process from the switching point (S114). That is, the step input control means 32 subtracts a predetermined phase angle value for each predetermined time (T2) from the phase angle value of the switching point and outputs it to the phase control means 38.
This process ends when the phase angle value reaches the target phase angle value, and shifts to normal control (input power constant control).

The step input control means 32 controls the operation when the switch (strong mode or weak mode) of the hand switch section 24 is operated during the motor starting process up to the switching point (S113). The means 30 detects it and determines whether or not the operation signal is in the strong mode (S115), and when it is in the strong mode, performs power control corresponding to the strong mode to the phase angle computing means 36. (S116). If the operation signal is not in the strong mode, in this case, it is in the weak mode, and therefore the phase angle computing means 36 is caused to perform power control corresponding to the weak mode (S118). In this way, when the hand switch unit 24 is operated twice consecutively at the time of starting, the slow start function at the time of starting is released, and control corresponding to the operation signal (strong mode, weak mode) is performed.

3 (A) and 3 (B) are a characteristic diagram showing a transition of the phase angle value at the time of startup and a characteristic diagram of the input power value. In the phase angle value of FIG. 3A, the phase angle value is decreased by a predetermined value in units of a predetermined time (T1) up to the switching point, and after the switching point, a predetermined time (T1).
2, the phase angle value is decreased by a predetermined value in units of T2 <T1). In the input power value of FIG. 3B, T1> T
From the relationship of 2, the change in rising up to the switching point is large after the switching point. Since the phase angle control is performed in this manner, FIG.
The characteristics shown in are obtained. FIG. 6C shows the starting characteristics of the suction motor at 0 ° C. according to this embodiment. As can be seen from this characteristic, the conventional method 2
The target speed is reached in the same time as when 0 ° C.

Next, the normal control after starting (constant input power control) will be described. Generally, the input electric power can be controlled to be constant by controlling the phase angle to be constant, but it is known that the driving current varies depending on the air volume of the suction motor. Therefore,
The input power can be controlled to be constant by setting the relationship between the phase angle and the drive current with the air volume as a parameter, storing the relationship in the nonvolatile memory 22, and controlling the phase angle according to the air volume. .

FIG. 4 is a characteristic diagram showing the relationship between the phase angle and the drive current in the weak mode, for example. It can be seen that even with the same phase angle, the drive current takes different values depending on the air volume. The phase angle calculation means 36 calculates the phase angle using this characteristic. For example, when the weak mode is set, the initial phase angle value stored as the initial value corresponding to the weak mode. Set TLS. As the initial phase angle value, as shown in FIG. 4, for example, the initial phase angle value TLS is set for the target current characteristic Ltw using the air flow rate a as a guide. The phase control means 38 generates a drive pulse signal based on the initial phase angle value TLS to drive the bidirectional thyristor 14, and the suction motor 12 is operated. Then, the current flowing through the suction motor 12 is detected by the current detecting means 18 and sent to the phase angle calculating means 36.

The phase angle calculation means 36 determines the target current characteristic Ltw.
From the intersection of the target current characteristic Ltw and the initial phase angle value TLs ILS
(Target current value) is calculated. Then, the detected current value Iout is compared with the target current value ILS, and if ILS> Iout, the phase is controlled with the input power value being lower than the target input power value WL. Therefore, based on the value of Iout, an airflow characteristic curve (airflow b in the example of FIG. 4) that passes above this value of Iout is estimated, and the intersection point IL of this estimated airflow characteristic curve and the target current characteristic Ltw is calculated, and this IL is calculated. A target phase angle value TLout that satisfies the above condition is calculated (intersection with the horizontal axis with a vertical line drawn from IL). Then, the phase control means 38 drives the bidirectional thyristor 14 based on the target phase angle value TLout, so that ILS (IL) = Iout and the target input power value W
L is obtained.

Embodiment 2. In the first embodiment described above, the example of the predetermined time T1 <T2 has been described (see FIG. 3), but conversely, T1> T2 may be set. In that case, the increase rate of the input power up to the switching point can be suppressed, and the inrush current at the time of startup can be effectively suppressed. Then, by increasing the increase rate of the input power after the switching point, it is possible to accelerate the rise of the rotation speed and shorten the time required to reach the target rotation speed as a whole.

Embodiment 3. Further, in the above-described first embodiment, an example in which two types of predetermined time (T1, T2) are provided has been described, but three or more types may be provided.

[0024]

As described above, according to the present invention, a plurality of types of predetermined times are set, and a predetermined phase angle and a phase angle value corresponding to the input power specified by the operation signal are set to a predetermined value. Since the time is switched, it is possible to change the increase rate of input before and after switching, and the arrival time can be changed arbitrarily, so even if the environmental temperature is low The motor can quickly reach the target speed.

The first predetermined time T1 before switching
Since the second predetermined time T2 after switching is set to T1 <T2, the increase rate of the input power up to the switching point is increased, so that the rise is quick and the time to the target rotation speed is shortened. Is possible.

The first predetermined time T1 before switching
Since the second predetermined time T2 after switching is set to T1> T2, it is possible to effectively suppress the inrush current at startup by suppressing the increase rate of the input power up to the switching point. Also, by increasing the increase rate of the input power after the switching point, it is possible to accelerate the rise of the rotation speed and shorten the time to the target rotation speed as a whole.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of an electric vacuum cleaner according to a first embodiment of the present invention.

FIG. 2 is a flow chart showing a processing procedure when the microcomputer of FIG. 1 is activated.

FIG. 3 is a characteristic diagram showing a transition of a phase angle value at the time of starting the suction motor and a characteristic diagram of an input power value.

FIG. 4 is a characteristic diagram showing a relationship between a phase angle and a drive current in a weak mode.

FIG. 5 is a characteristic diagram showing a relationship between temperature and air density.

FIG. 6 is a diagram showing a starting characteristic of a suction motor according to a conventional method at an ambient temperature of 20 ° C. and 0 ° C. and a starting characteristic of a suction motor according to Embodiment 1 of the present invention at an ambient temperature of 0 ° C.

[Explanation of symbols]

10 Commercial Power Supply, 12 Suction Motor, 14 Bidirectional Thyristor, 16 Power Supply Synchronization Detection Means, 18 Current Detection Means, 20 Microcomputer, 22 Nonvolatile Memory, 24 Hand Switch Unit, 30 Operation Control Means, 32
Step input control means, 34 motor start confirmation means,
36 phase angle calculation means, 38 phase control means.

Continued front page    (72) Inventor Akihiro Iwahara             1728 Omaeda, Hanazono-cho, Osato-gun, Saitama 1728               Within Mitsubishi Electric Home Equipment Co., Ltd. (72) Inventor Kitakomi Sou             1728 Omaeda, Hanazono-cho, Osato-gun, Saitama 1728               Within Mitsubishi Electric Home Equipment Co., Ltd. F-term (reference) 3B057 DA02

Claims (3)

[Claims] 1. An operation control means for fetching an operation signal for defining an input power of a suction motor based on an operation of an operation section, and a predetermined phase angle value at the time of starting the suction motor, which is controlled by the operation signal. Step input control means for outputting a phase angle value that is changed stepwise at predetermined time up to a phase angle value corresponding to a specified input power, and a suction motor based on the phase angle value from the step input control means. In a vacuum cleaner provided with a phase angle control means for controlling, the step input control means sets a plurality of types of the predetermined time, and sets the predetermined phase angle value and the input power specified by the operation signal. An electric vacuum cleaner, characterized in that the predetermined time is switched between corresponding phase angle values. 2. The vacuum cleaner according to claim 1, wherein the first predetermined time T1 before switching and the second predetermined time T2 after switching are T1 <T2. 3. The vacuum cleaner according to claim 1, wherein a first predetermined time T1 before switching and a second predetermined time T2 after switching are T1> T2.