JP2020178915A - Vacuum cleaner - Google Patents

Abstract

To reduce harsh unpleasant sound that may be emitted by variation in output voltage of a battery.SOLUTION: A vacuum cleaner (1) has a duty determination unit (232) for controlling a pulse generating unit (231) for generating a PWM-controlled pulse voltage so that the rotation number of a motor (241) of an electric blower (24) is within a range between a high-rotation area where the rotation number is equal to or larger than a first rotation number and a low-rotation area where the rotation number is equal to or smaller than a second rotation number that is smaller than the first rotation number.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vacuum cleaner equipped with a battery.

The electric vacuum cleaner is provided with an electric blower for sucking dust together with air and collecting it in a dust collecting unit. In order to control the suction force of the electric blower, the rotation speed of the motor of the electric blower is controlled.

Japanese Patent No. 4679308

The motor of the electric blower rotates at a high speed of several thousand revolutions per minute or more. Therefore, in a specific rotation speed range, the motor generates an unpleasant noise due to resonance. Therefore, conventionally, the rotation speed of the motor of the electric blower has been set while avoiding the band that generates unpleasant noise. In the prior art as in Patent Document 1, since commercial alternating current is used as the power source for the electric vacuum cleaner, the power source voltage does not fluctuate. Therefore, the set value does not fluctuate significantly from the rotation speed of the motor, and an unpleasant noise does not occur.

However, when a battery is used as a power source for an electric blower as in a cordless vacuum cleaner, the output voltage of the battery decreases with discharge. Such a change in the output voltage of the battery causes a fluctuation in the rotation speed of the motor. Then, even when the rotation speed range that causes an unpleasant sound in the fully charged state is avoided, an unpleasant unpleasant sound may be generated as the output voltage decreases.

One aspect of the present invention is to realize a vacuum cleaner that uses a battery as a power source for an electric blower and can reduce the generation of annoying unpleasant noise that may occur due to a change in the output voltage of the battery.

In order to solve the above problems, the electric vacuum cleaner according to one aspect of the present invention supplies the motor with an electric blower having a motor, a battery, and PWM (Pulse Width Modulation) control of the output from the battery. The control unit includes a rotation speed detection unit that detects the rotation speed of the motor, and the control unit includes a pulse generation unit that generates the PWM-controlled pulse voltage, and the rotation speed detection unit from the rotation speed detection unit. A duty determining unit that determines the pulse duty by referring to a signal indicating the rotation speed and controls the pulse generating unit is provided. In the duty determining unit, the rotation speed of the motor is equal to or higher than the first rotation speed. The pulse generating unit is controlled so as to be within the range of the high rotation speed region, which is lower than the first rotation speed, and the low rotation speed region, which is less than the second rotation speed.

According to one aspect of the present invention, in a vacuum cleaner that uses a battery as a power source for an electric blower, it is possible to realize a vacuum cleaner that can reduce the generation of annoying unpleasant noise that may occur due to a change in the output voltage of the battery.

It is a perspective view which looked at the electric vacuum cleaner which concerns on Embodiment 1 from diagonally rearward. It is a block diagram which shows the structure of the electric vacuum cleaner which concerns on Embodiment 1. FIG. It is a time chart which shows the operation example of the electric vacuum cleaner which concerns on Embodiment 1. It is a time chart which shows the operation example of the electric vacuum cleaner which concerns on Embodiment 2. It is a block diagram which shows the structure of the electric vacuum cleaner which concerns on Embodiment 3. It is a time chart which conceptually shows the operation example of the electric vacuum cleaner which concerns on Embodiment 3.

[Embodiment 1]
Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS.

(Overall shape of vacuum cleaner)
FIG. 1 is a perspective view of the vacuum cleaner 1 according to the first embodiment as viewed obliquely from the rear. The electric vacuum cleaner 1 is a so-called stick-type cordless vacuum cleaner, which is provided with an electric blower accommodating portion 14 and a dust collecting portion 15 on one side (upper side) and a suction port body 19 on the other end (lower end). The dust collecting unit 15 is directly connected below the electric blower accommodating unit 14. The dust collecting unit 15 includes a filter storage unit 151 on the side of the electric blower accommodating unit 14 and a dust collecting container 152 on the opposite side.

Here, in a scene where the user uses the vacuum cleaner 1 to clean the floor surface, the direction on the floor surface side is down along the long axis of the vacuum cleaner 1, and the opposite direction is up. Further, the direction in which the user pushes the vacuum cleaner 1 is set to be forward, and the direction in which the user pulls the vacuum cleaner 1 is set to backward.

The upper end of the vacuum cleaner 1 is a handle 12. In front of the vacuum cleaner 1, a drive device accommodating portion 13 and a suction pipe portion 16 which are continuous portions downward from the handle 12 continue. An electric blower accommodating unit 14 is located behind the drive device accommodating unit 13. A dust collecting portion 15 is located behind the suction pipe portion 16. The battery unit 11 is detachably connected to the rear of the electric blower accommodating portion 14.

The dust collecting portion 15 is connected to the suction pipe portion 16, and the suction pipe portion 16 and the suction port body 19 are communicated with each other via the extension pipe 17.

The suction port body 19 is composed of a suction port main body 193 that runs in the front-rear direction on the floor surface, a joint portion 192 on the upper side thereof, and a tubular connection portion 191 on the upper side thereof. The suction port main body 193 is provided with a suction port 194 at the bottom (lower side). The suction port body 19 has a rotary brush 195 rotatably provided in the vicinity of the suction port 194. The suction port main body 193 is communicated and connected to the extension pipe 17 through the joint portion 192 and the tubular connecting portion 191.

(Vacuum cleaner functional block)
FIG. 2 is a block diagram showing a functional block of the vacuum cleaner 1 according to the first embodiment. As shown in the figure, the vacuum cleaner 1 includes a battery 20, a drive power supply circuit 21, a control power supply circuit 22, a control unit 23, an electric blower 24, a rotation speed detection unit 25, and an operation unit 26. The control unit 23 is provided with at least a pulse generation unit 231 and a duty determination unit 232. The electric blower 24 is provided with a motor 241 and a fan 242.

The battery 20 is housed inside the battery unit 11. The battery 20 is a secondary battery that supplies electric power to the entire vacuum cleaner 1. The output of the battery 20 is supplied to the pulse generator 231 through the drive power supply circuit 21. The drive power supply circuit 21 is a circuit for converting the output voltage of the battery 20 into an appropriate voltage and supplying it to the pulse generation unit 231.

Further, the output of the battery 20 is supplied to the control unit 23 through the control power supply circuit 22. The control power supply circuit 22 is a circuit for converting and supplying the output voltage from the battery 20 to a circuit portion that operates at a relatively low voltage, such as the duty determination unit 232 of the control unit 23.

The control unit 23 is housed inside the drive device housing unit 13. The pulse generation unit 231 is a circuit that generates a PWM-controlled pulse voltage based on the DC output from the battery 20 and supplies it to the motor 241 of the electric blower 24. The pulse generation unit 231 turns the input DC voltage on / off by the switching element to perform chopping, and generates a PWM-controlled pulse voltage. When the pulse duty (duty ratio) is constant, the pulse voltage output by the pulse generating unit 231 fluctuates depending on the output voltage from the battery 20. The pulse duty (duty ratio) of the pulse output by the pulse generation unit 231 is controlled by the duty determination unit 232.

The electric blower 24 is housed inside the electric blower accommodating portion 14. The fan 242 is driven by the motor 241 of the electric blower 24, and a suction force for sucking in dust is generated according to the rotation speed. The motor 241 of the electric blower 24 is a DC motor, and its rotation speed depends on the average voltage of the pulses output by the pulse generating unit 231. A smoothing circuit may be provided between the pulse generating unit 231 and the motor 241 of the electric blower 24.

The rotation speed detection unit 25 detects the rotation speed of the motor 241 and outputs a signal indicating the rotation speed to the duty determination unit 232. The rotation speed detection unit 25 may include a magnetic or optical sensor and directly detect the rotation speed. Alternatively, the rotation speed may be detected by detecting the current waveform flowing through the motor 241. Alternatively, the rotation speed may be indirectly detected by the temperature of the motor 241.

The duty determination unit 232 determines the pulse duty (duty ratio) of the pulse output with reference to the signal indicating the rotation speed from the rotation speed detection unit 25, and executes PWM control for generating the pulse output in the pulse generation unit 231. To do. The duty determination unit 232 can feedback control the rotation speed of the motor 241 through the rotation speed detection unit 25.

The operation unit 26 (not shown in FIG. 1) provided on the front surface of the drive device accommodating unit 13 is provided with a user-operated switch for changing the suction force during operation of the vacuum cleaner 1 to be strong or weak. ing. The operation unit 26 transmits a signal indicating that the strong mode or the weak mode is selected to the duty determination unit 232 according to the operation of the user. The duty determination unit 232 can adjust the target value of the rotation speed of the motor 241 of the electric blower 24 based on the signal.

It is not essential that the vacuum cleaner 1 has such a suction force mode switching function, and in that case, the operation unit 26 may be omitted. Further, in that case, the vacuum cleaner 1 is synonymous with operating only in the above-mentioned strong mode.

(Operation of vacuum cleaner)
FIG. 3 is a time chart showing an operation example of the first embodiment of the vacuum cleaner 1. In the figure, the rotation speed of the motor 241 of the electric blower 24 and the pulse duty (duty ratio) of the pulse output by the pulse generating unit 231 are shown. In the following, it is assumed that the vacuum cleaner 1 is set to the strong mode.

In FIG. 3, a region in which the rotation speed range of the motor 241 of the electric blower 24 is more than 71000 rpm and less than 75000 rpm is indicated by the symbol Z. This region Z is the range of the rotation speed at which the motor 241 of the electric blower 24 generates an unpleasant noise in the vacuum cleaner 1 of the first embodiment. The control unit 23 is set below so that the rotation speed is within the range of the high rotation speed region H of 75,000 rpm (first rotation speed) or more and the low rotation speed region L of 71,000 rpm (second rotation speed) or less. As shown, the rotation speed of the motor 241 of the electric blower 24 is controlled.

At the start of the first period T1, the battery 20 is assumed to be fully charged. The initial target value of the rotation speed is 77,000 rpm, and the duty determination unit 232 adjusts the pulse duty (duty ratio) so as to reach the rotation speed, and determines 81% in the example of FIG.

When the output voltage from the battery 20 decreases as the battery 20 is discharged during the period T1, the pulse voltage of the pulse output by the pulse generator 231 decreases if the pulse duty (duty ratio) remains at 81% of the initial value. .. However, the duty determination unit 232 executes feedback control so as to maintain the rotation speed. This is to maintain a constant suction force of the vacuum cleaner 1. The duty determination unit 232 gradually increases the pulse duty (duty ratio) in order to compensate for the decrease in the average voltage of the pulse.

A maximum value is set for the value of the pulse duty (duty ratio), and in the first embodiment, it is set to 90% as an example. The maximum value is for ensuring safety according to the configuration of the motor, battery, and housing. The maximum value can be 100%. When the pulse duty (duty ratio) reaches the maximum value as a result of gradually increasing the pulse duty (duty ratio), the rotation speed of 77,000 rpm can no longer be maintained (end of period T1).

Then, the duty determination unit 232 resets the next target rotation speed to 76000 rpm, which is a value lower than the initial target rotation speed of 77000 rpm, and gradually lowers the pulse duty (duty ratio) (period T2). ). When the rotation speed detected by the rotation speed detection unit 25 reaches the reset target rotation speed of 76000 rpm, the duty determination unit 232 executes feedback control so as to maintain the rotation speed (start of period T3).

In the period T3 as well, the duty determination unit 232 gradually increases the pulse duty (duty ratio) in order to compensate for the decrease in the average voltage of the pulse, as in the period T1. When the pulse duty (duty ratio) reaches 90% of the maximum value, it can no longer maintain the rotation speed of 76000 rpm (end of period T3).

Then, the duty determination unit 232 resets the next target rotation speed to a further reduced value of 75,000 rpm. The duty determination unit 232 gradually reduces the pulse duty (duty ratio) (period T4). When the rotation speed detected by the rotation speed detection unit 25 reaches the reset target rotation speed of 75,000 rpm, the duty determination unit 232 executes feedback control so as to maintain the rotation speed (start of period T5).

In the period T5 as well, the duty determination unit 232 gradually increases the pulse duty (duty ratio) in order to compensate for the decrease in the average voltage of the pulse, as in the period T1. When the pulse duty (duty ratio) reaches 90% of the maximum value, it can no longer maintain the rotation speed of 75,000 rpm (end of period T5).

Since the rotation speed of 75,000 rpm is the lower limit of the high rotation speed region H, if the target rotation speed is set to a value slightly lower than this, an unpleasant noise that is offensive to the ears is generated. Therefore, the duty determination unit 232 next sets the target rotation speed to 71000 rpm, which is the upper limit of the low rotation speed region L. The duty determination unit 232 reduces the pulse duty (duty ratio) (period T6). When the rotation speed detected by the rotation speed detection unit 25 reaches 71,000 rpm, feedback control is executed so as to maintain the rotation speed (start of period T7).

The duty determination unit 232 reduces the pulse duty (duty ratio) in the region Z of the rotation speed where an unpleasant noise is generated, and suppresses the user from feeling uncomfortable due to a sudden change in the rotation speed. (Duty ratio) is gradually reduced. For example, the pulse duty (duty ratio) may be reduced by 0.1% every 0.3 seconds. However, in order to shorten the generation period of the unpleasant sound in the region Z as much as possible, it is possible to sharply reduce the pulse duty (duty ratio).

According to the vacuum cleaner 1 according to the first embodiment, it is possible to reduce the generation of annoying unpleasant noise from the motor 241 of the electric blower 24 regardless of the fluctuation of the output voltage of the battery 20. Therefore, it is possible to realize the battery-powered vacuum cleaner 1 in which the discomfort of the user is suppressed.

Further, the vacuum cleaner 1 is realized, which controls the motor 241 of the electric blower 24 in a stepwise manner as the output voltage of the battery 20 decreases, while controlling the motor 241 to exert a constant suction force as much as possible. be able to.

(Additional notes)
When the vacuum cleaner 1 has a suction force mode switching function, it is desirable that the target rotation speed in the initial state without a voltage drop due to the discharge of the battery 20 is set as follows. The target rotation speed in the strong mode is set to a rotation speed higher than the lower limit value (first rotation speed) of the high rotation region H, and the target rotation speed in the weak mode is set to be in the low rotation speed region L.

When the user is using the vacuum cleaner 1 in the strong mode with high suction power, feedback control is performed so that the control unit 23 has a constant value as the output voltage of the battery 20 decreases as shown in FIG. The target rotation speed gradually decreases. In the first embodiment, the range of rotation speeds (region Z) at which an unpleasant harsh sound is generated is set to a range of more than 71000 rpm and less than 75000 rpm. However, the range of the number of revolutions that the user feels unpleasant differs depending on the user. A sensitive user may feel uncomfortable even when the rotation speed is 75,000 rpm, or may feel that some abnormality has occurred in the vacuum cleaner 1.

In such a case, the user operates the operation unit 26 to try to eliminate the unpleasant or abnormal state. As a result, the weak mode is selected by switching the suction force mode, and the state of feeling uncomfortable or abnormal is eliminated. Then, the discomfort is resolved, and the user continues to use the vacuum cleaner 1.

In this way, in addition to the configuration that avoids the region of a certain number of rotations, by providing the suction force mode switching function, it works so that the discomfort of the user who is sensitive to unpleasant sounds can be eliminated. Can be done.

[Embodiment 2]
Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals will be added to the members having the same functions as the members described in the above embodiment, and the description will not be repeated. The same applies to the following embodiments.

The configuration of the vacuum cleaner according to the second embodiment is the same as that of the vacuum cleaner 1 of the first embodiment shown in FIGS. 1 and 2. The second embodiment is an example in which the method of determining the target value of the rotation speed set by the duty determination unit 232 is different from that of the first embodiment.

FIG. 4 is a time chart for explaining the operation of the vacuum cleaner 1 in the second embodiment. In the following, it is assumed that the vacuum cleaner 1 is set to the strong mode.

At the start of the first period T1, the battery 20 is assumed to be fully charged. The initial target value of the rotation speed is 77,000 rpm, and the duty determination unit 232 determines the pulse duty (duty ratio) to be 81% so as to reach the rotation speed.

During the period T1, the duty determination unit 232 controls the pulse generation unit 231 so as to maintain the initial pulse duty (duty ratio) of the period T1. Since the pulse duty (duty ratio) is constant, the pulse voltage of the pulse output by the pulse generating unit 231 decreases as the battery 20 is discharged. Then, as the pulse voltage decreases, the average voltage of the pulse also decreases, so that the rotation speed gradually decreases.

When the duty determination unit 232 detects through the rotation speed detection unit 25 that the rotation speed reaches the lower limit value (first rotation speed) of the high rotation speed region H (first rotation speed) of 75,000 rpm (end of period T1), the next target The rotation speed is set to 71000 rpm, which is the upper limit (second rotation speed) of the low rotation speed region L.

The duty determination unit 232 reduces the pulse duty (duty ratio) (period T2). When the rotation speed detected by the rotation speed detection unit 25 reaches 71,000 rpm due to the decrease in the rotation speed, the pulse duty (duty ratio) is then maintained (start of period T3). In the example of FIG. 4, the pulse duty (duty ratio) at that time was 76%. The pulse duty (duty ratio) at the start of the period T3 does not have to be determined according to the detection result of the rotation speed detection unit 25, and may be a predetermined value.

In the period T3, the duty determination unit 232 controls the pulse generation unit 231 so as to maintain the initial pulse duty (duty ratio) of the period T3. Since the pulse duty (duty ratio) is constant, the pulse voltage of the pulse output by the pulse generating unit 231 decreases as the battery 20 is discharged. Then, as the pulse voltage decreases, the average voltage of the pulse also decreases, so that the rotation speed gradually decreases.

Also in the second embodiment, it is possible to suppress the generation of annoying unpleasant noise from the motor 241 of the electric blower 24 regardless of the fluctuation of the output voltage of the battery 20. Therefore, it is possible to realize the battery-powered vacuum cleaner 1 in which the discomfort of the user is suppressed.

In the first embodiment, in order to keep the suction force as constant as possible, the pulse duty (duty ratio) is gradually increased in each period. On the other hand, in the second embodiment, the pulse duty (duty ratio) is realized at the beginning of each period in each of the operation period T1 in the high rotation region H and the operation period T3 in the low rotation region L. It is fixed to the value when it was done. Therefore, the pulse duty (duty ratio) does not rise to a high value during the period, and depending on the value of the pulse duty (duty ratio), the consumption of the battery capacity is suppressed by that amount as compared with the first embodiment. To. Therefore, in the second embodiment, a battery-powered vacuum cleaner capable of operating for a longer time is realized.

[Embodiment 3]
FIG. 5 is a diagram showing a functional block of the vacuum cleaner according to the third embodiment. Compared with the vacuum cleaner 1 according to the first embodiment, the vacuum cleaner according to the third embodiment is different in that it includes a notification unit 27. The notification unit 27 is a functional block that receives a command from the duty determination unit 232 and notifies the user of information. Although the operation unit 26 according to the first embodiment is not provided in FIG. 5, the vacuum cleaner according to the third embodiment may be provided with the operation unit 26.

In the operation of the vacuum cleaner 1 of the first embodiment in FIG. 3 in the high rotation speed region H, each step (with period T3) after the pulse duty (duty ratio) once reaches the maximum value of 90% and the target rotation speed is lowered. The transition of the pulse duty (duty ratio) in the period T5) is the same in each step. This is because, in each step of the target rotation speed, after the pulse duty (duty ratio) reaches the maximum value of 90%, the target rotation speed is lowered by the same amount to a certain value.

The vacuum cleaner of the third embodiment pays attention to this point, and in the steps (period T3 and period T5) after the pulse duty (duty ratio) reaches the maximum value and the target rotation speed is lowered. It performs a characteristic operation. The operation of the vacuum cleaner according to the third embodiment will be described with reference to the time chart of FIG. FIG. 6 is a time chart similar to that of FIG.

When the filter (installed in the filter storage section 151) for preventing dust from being sucked into the electric blower 24 is clogged, or, for example, when the suction port 194 is closed by sucking the cloth (closed state). If this happens, the load on the motor 241 of the electric blower 24 is reduced and the rotation speed tends to increase. When the feedback control is performed so as to maintain a constant target rotation speed, the duty determination unit 232 reduces the pulse duty (duty ratio) in order to maintain the rotation speed. T3a in the period T3 and T5a in the period T5 in FIG. 6, which are shown to reduce the pulse duty (duty ratio), conceptually show such a phenomenon. Further, in T3b in the period T3 and T5b in the period T5 shown in FIG. 6 in which the pulse duty (duty ratio) is shown to increase, such a phenomenon is eliminated by the user's response and the normal situation is restored. The state is conceptually shown.

D1 in the periods T3 and T5 of FIG. 6 is a pulse duty (duty ratio) corresponding to a clogging state (occlusion degree) that requires filter replacement, filter cleaning, or removal of an object that blocks the suction port 194. Shows the value. When the determined pulse duty (duty ratio) becomes D1 or less in the period T3 or the period T5, the duty determination unit 232 instructs the notification unit 27 to replace or clean the filter, or remove an object that blocks the suction port 194. Notify the user that is required. Specifically, the method of notification is indicated by lighting a lamp.

Further, if the filter becomes severely clogged, or if the suction port 194 is blocked by the sucked object, it becomes difficult to suck the dust. In such a case, it is also possible to control the operation of the vacuum cleaner to be forcibly stopped. D2 in the periods T3 and T5 of FIG. 6 indicates a pulse duty (duty ratio) value corresponding to a state in which it becomes difficult to continue sucking such dust. Naturally, D2 is a value smaller than D1.

When the determined pulse duty (duty ratio) becomes D2 or less in the period T3 or the period T5, the duty determination unit 232 instructs the notification unit 27 to notify the user that the filter needs to be replaced. At that time, the duty determination unit 232 controls the pulse generation unit 231 to stop the generation of the pulse.

The same effect as that of the first embodiment can be obtained in the third embodiment. Further, the user can recognize that the filter needs to be replaced or cleaned, or the object blocking the suction port 194 needs to be removed, which enhances the convenience of the user. Further, by forcibly stopping the operation of the vacuum cleaner, it is difficult to suck the dust, but the operation is not continued. Therefore, the user can recognize that the filter needs to be replaced immediately, and the convenience of the user is further enhanced.

[Example of realization by software]
The functional block (particularly the duty determination unit 232) of the vacuum cleaner 1 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the vacuum cleaner 1 includes a computer that executes the instructions of a program that is software that realizes each function. The computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, in addition to a "non-temporary tangible medium" such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. In addition, one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

[Summary]
The electric vacuum cleaner according to the first aspect of the present invention includes an electric blower having a motor, a battery, a control unit that PWM-controls the output from the battery and supplies the motor, and a rotation that detects the rotation speed of the motor. The control unit includes a number detection unit, and the control unit determines the pulse duty with reference to the pulse generation unit that generates the PWM-controlled pulse voltage and the signal indicating the rotation speed from the rotation speed detection unit. A duty determining unit that controls the pulse generating unit is provided, and the duty determining unit is based on a high rotation region in which the rotation speed of the motor is equal to or higher than the first rotation speed and the first rotation speed. The pulse generating unit is controlled so as to be within the range of the low rotation region which is smaller than the second small rotation speed.

According to the above configuration, in a vacuum cleaner that uses a battery as a power source for an electric blower, it is possible to realize a vacuum cleaner that can reduce the generation of annoying unpleasant noise that may occur due to a change in the output voltage of the battery.

In the electric vacuum cleaner according to the second aspect of the present invention, in the first aspect, the duty determining unit controls the pulse generating unit so that the rotation speed of the motor is within the high rotation speed region, and outputs the battery. When the rotation speed of the motor cannot maintain the first rotation speed or higher due to the decrease in voltage, the pulse generating unit is controlled so that the rotation speed of the motor is within the low rotation speed region. It may have a configuration.

According to the above configuration, in an electric vacuum cleaner that uses a battery as a power source for an electric blower, it is possible to realize an electric vacuum cleaner that can reduce the generation of annoying unpleasant noise that may occur due to a decrease in the output voltage of the battery due to electric discharge.

In the vacuum cleaner according to the third aspect of the present invention, in the second aspect, the duty determination unit shifts from the control in the high rotation speed region to the control in the low rotation speed region by the rotation speed of the motor. A configuration may be provided in which the pulse generating unit is controlled and executed so as to gradually change.

According to the above configuration, it is possible to realize a vacuum cleaner that suppresses the user from feeling uncomfortable due to a sudden change in the rotation speed.

In the vacuum cleaner according to the fourth aspect of the present invention, in any one of the first to third aspects, the duty determining unit controls the pulse generating unit so that the rotation speed of the motor becomes a constant value, and the pulse generating unit is described. When the rotation speed of the motor cannot maintain the constant value due to a decrease in the output voltage of the battery, the pulse is generated so that the rotation speed of the motor becomes another constant value lower than the constant value. It may have a structure for controlling a unit.

According to the above configuration, it is possible to realize an electric vacuum cleaner that controls to exert a constant suction force as much as possible while gradually reducing the rotation speed of the motor of the electric blower as the output voltage of the battery decreases. can do.

In the electric motor according to the fifth aspect of the present invention, in any one of the first to third aspects, the duty determining unit controls the pulse generating unit so that the pulse duty becomes a constant value, and outputs the battery. When the rotation speed of the motor cannot be maintained at least the first rotation speed due to a decrease in voltage, the rotation speed of the motor falls within the low rotation speed region, and the pulse duty becomes higher than the constant value. A configuration may be provided in which the pulse generating unit is controlled so as to have another low constant value.

According to the above configuration, it is possible to realize an electric vacuum cleaner capable of suppressing battery consumption and operating for a long time while reducing the generation of annoying unpleasant noise.

In any of the above aspects 1 to 5, the vacuum cleaner according to the sixth aspect of the present invention has a strong mode in which the control target of the rotation speed of the motor is equal to or higher than the first rotation speed, and the second rotation. It has a number of weak modes or less, and may further include an operation unit that receives a user operation instructing the strong mode or the weak mode and transmits the operation unit to the duty determination unit.

According to the above configuration, it is possible to act so as to eliminate the discomfort of the user who is sensitive to unpleasant sounds.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

1 Vacuum cleaner 11 Battery unit 12 Handle 13 Drive unit housing 14 Electric blower housing 15 Dust collector 151 Filter storage 152 Dust collecting container 16 Suction pipe 17 Extension pipe 19 Suction port 191 Tubular connection 192 Joint 193 Suction port body 194 Suction port 195 Rotating brush 20 Battery 21 Drive power supply circuit 22 Control power supply circuit 23 Control unit 231 Pulse generator 232 Duty determination unit 24 Electric blower 241 Motor 242 Fan 25 Rotation speed detection unit 26 Operation unit 27 Notification unit

Claims (6)

An electric blower with a motor and
With the battery
A control unit that PWM-controls the output from the battery and supplies it to the motor.
It is provided with a rotation speed detection unit that detects the rotation speed of the motor.
The control unit includes a pulse generation unit that generates the PWM-controlled pulse voltage, and a pulse generation unit.
A duty determination unit that determines the pulse duty with reference to a signal indicating the rotation speed from the rotation speed detection unit and controls the pulse generation unit is provided.
The duty determination unit is within a range of a high rotation speed region in which the rotation speed of the motor is equal to or higher than the first rotation speed and a low rotation speed region in which the rotation speed is lower than the first rotation speed and equal to or less than the second rotation speed. An electric motor characterized by controlling the pulse generating unit as described above. The duty determination unit
The pulse generating unit is controlled so that the rotation speed of the motor is within the high rotation region.
When the rotation speed of the motor cannot be maintained at least the first rotation speed due to a decrease in the output voltage of the battery, the pulse is generated so that the rotation speed of the motor is within the low rotation speed region. The electric vacuum cleaner according to claim 1, wherein the unit is controlled. The duty determination unit
The transition from the control in the high rotation region to the control in the low rotation region,
The vacuum cleaner according to claim 2, wherein the pulse generating unit is controlled and executed so that the rotation speed of the motor gradually changes. The duty determining unit controls the pulse generating unit so that the rotation speed of the motor becomes a constant value, and keeps the rotation speed of the motor at the constant value as the output voltage of the battery decreases. The invention according to any one of claims 1 to 3, wherein the pulse generating unit is controlled so that the rotation speed of the motor becomes another constant value lower than the constant value when it disappears. Electric vacuum cleaner. The duty determining unit controls the pulse generating unit so that the pulse duty becomes a constant value, and keeps the rotation speed of the motor at least the first rotation speed as the output voltage of the battery decreases. A claim characterized in that the pulse generating unit is controlled so that the rotation speed of the motor falls within the low rotation region and the pulse duty becomes another constant value lower than the constant value when the motor disappears. The electric vacuum cleaner according to any one of items 1 to 3. The control target of the rotation speed of the motor has a strong mode in which the rotation speed is equal to or higher than the first rotation speed and a weak mode in which the rotation speed is equal to or lower than the second rotation speed.
The vacuum cleaner according to any one of claims 1 to 5, further comprising an operation unit that receives a user operation instructing the strong mode or the weak mode and transmits the operation unit to the duty determination unit. ..

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