Driving apparatus for driving motor of cleaner and cleaner having the same

Abstract

To provide a technique for changing an operation sound of a vacuum cleaner while suppressing a change in performance of the vacuum cleaner.SOLUTION: A driving device of the present disclosure includes a motor that rotationally drives a rotary brush or a rotary blade of a cleaner by rotation of a rotor, and a voltage application unit that causes a periodic change in a magnetic field in the motor at a frequency corresponding to an application frequency of a voltage to the motor. The motor is configured such that a rotation speed of a rotor changes according to a current value that is a time average value of a direct current flowing through the motor with application of a voltage to the motor, and is configured such that the rotor vibrates according to a periodic change in a magnetic field at a frequency corresponding to an applied frequency to generate an operating sound. The drive device further includes an application control part for controlling the voltage application part so that the applied frequency is changed while suppressing fluctuation of the current value on condition that a predetermined change condition is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to drive techniques for driving motors in vacuum cleaners. [Background technology]

[0002] Various vacuum cleaners are known that are equipped with a suction source that generates suction force to suck up dust by rotating a rotating blade with a suction motor. When a user uses the vacuum cleaner, the vacuum cleaner emits the sound of the suction motor operating or the sound of the rotating blades rotating. If the rotation frequency of the suction motor is constant, these sounds do not change and are perceived by the user as nothing more than monotonous noise.

[0003] To solve this problem, Patent Document 1 controls the suction motor by increasing or decreasing the rotation frequency of the suction motor in accordance with the pitch of the notes on a predetermined musical score, so that the operating sound emitted from the suction source plays the melody represented on the musical score. With this control, the user can perform cleaning work while listening to the sound emitted from the vacuum cleaner as music, rather than just noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-28320 Summary of the Invention [Problem to be solved by the invention]

[0005] The control disclosed in Patent Document 1 increases or decreases the rotation frequency of the suction motor in accordance with the pitch of the notes on a predetermined musical score. When the rotation speed of the suction motor is reduced, the suction power of the vacuum cleaner decreases. Conversely, when the rotation speed of the suction motor is increased, the suction power of the vacuum cleaner increases. Therefore, while the control disclosed in Patent Document 1 allows the user to enjoy the operating sound of the vacuum cleaner as music, it has the problem of changing the performance of the vacuum cleaner.

[0006] The present disclosure aims to provide a technique for changing the operating noise of a vacuum cleaner while suppressing changes in the performance of the vacuum cleaner. [Means for solving the problem]

[0007] The drive device disclosed herein is configured to drive a rotating brush that rolls on a floor surface to scrape dust off the floor surface, or a rotating blade that generates a suction force to suck in dust as it rotates. The drive device includes a motor having a rotor that rotates the rotating brush or the rotating blade, and a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in the magnetic field within the motor at a frequency corresponding to the frequency of the voltage applied to the motor. The motor is configured so that the rotor rotates at a rotation speed corresponding to a current value that is the time average value of a direct current flowing through the motor as a result of the intermittent application of voltage to the motor, and vibrates in response to the periodic change in the magnetic field at a frequency corresponding to the applied frequency, thereby emitting an operating sound. The drive device further includes an application control unit that controls the voltage application unit to change the applied frequency while suppressing fluctuations in the current value, provided that a predetermined change condition is met.

[0008] The vacuum cleaner of the present disclosure includes a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade configured to generate suction force for sucking in dust while rotating, the drive device described above, a storage battery that stores power for the motor, and a power detection unit that detects the remaining amount of power stored in the storage battery. The application control unit controls the voltage application unit to change the application frequency while suppressing fluctuations in the current value, on the condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold.

[0009] Another vacuum cleaner of the present disclosure includes a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade configured to generate suction force for sucking in dust as it rotates, the drive device described above, a dust storage unit that stores the dust scraped by the rotating brush or dust sucked in by the suction force generated by the rotation of the rotating blade, and a dust storage detection unit that detects the amount of dust in the dust storage unit. The application control unit controls the voltage application unit to change the applied frequency while suppressing fluctuations in the current value, on the condition that it detects that the amount of dust in the dust storage unit has exceeded a predetermined dust storage threshold.

[0010] Another vacuum cleaner according to the present disclosure includes a rotating brush that rolls on a floor surface to scrape off dust or rotating blades that are configured to generate a suction force for sucking in dust as they rotate, the drive device described above, and a dust detection unit that detects the amount of dust being scraped off by the rotating brush or the amount of dust being sucked in by the suction force generated by the rotation of the rotating blades. The application control unit controls the voltage application unit to change the application frequency while suppressing fluctuations in the current value, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

[0011] The present disclosure also provides a vacuum cleaner including a rotating brush that rolls on a floor surface to scrape off dust or a rotating blade configured to generate suction force for sucking in dust as it rotates, the drive device described above, and a motor housing that houses a motor so that vibrations of the rotor are transmitted. The application control unit controls the voltage application unit so that the application frequency approaches the resonant frequency of the motor housing while suppressing fluctuations in the current value, provided that a change condition is satisfied.

[0012] Another drive device according to the present disclosure is configured to drive a first rotating brush and a second rotating brush that roll on a floor surface to scrape off dust. The drive device includes a first motor having a first rotor that rotatably drives the first rotating brush, a second motor having a second rotor that rotatably drives the second rotating brush, a first voltage application unit that applies a predetermined voltage to the first motor intermittently to cause a periodic change in the magnetic field within the first motor at a frequency corresponding to the frequency of the voltage applied to the first motor, and a second voltage application unit that applies a predetermined voltage to the second motor intermittently to cause a periodic change in the magnetic field within the second motor at a frequency corresponding to the frequency of the voltage applied to the second motor. The first motor is configured such that the first rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the first motor as a result of the intermittent application of the voltage to the first motor, and vibrates in response to the periodic change in the magnetic field at a frequency corresponding to the frequency of the voltage applied to the first motor, thereby emitting an operating sound. The second motor is configured such that the second rotor rotates at a rotation speed corresponding to a current value, which is a time average value of a direct current flowing through the second motor, in response to the intermittent application of a voltage to the second motor, and the second rotor vibrates in response to a periodic change in the magnetic field at a frequency corresponding to the frequency applied to the second motor, thereby emitting an operating sound. The drive device further includes an application control unit that controls the first voltage application unit and the second voltage application unit. The application control unit controls the first voltage application unit to change the frequency applied to the first motor while suppressing fluctuations in the current value to the first motor, and controls the second voltage application unit to make the frequency applied to the second motor different from the frequency applied to the first motor while suppressing fluctuations in the current value to the second motor, on the condition that a predetermined change condition is satisfied, thereby generating a discordant or consonant sound by the operating sounds of the first motor and the second motor.

[0013] Yet another vacuum cleaner according to the present disclosure includes a first rotating brush and a second rotating brush that roll over a floor surface to scrape off dust from the floor surface, the drive device described above, a storage battery that stores power for the first motor and the second motor, and a power detection unit that detects the remaining amount of power stored in the storage battery. The application control unit controls the first voltage application unit and the second voltage application unit so as to suppress fluctuations in the current values ​​for the first motor and the second motor and to produce a discordant sound from the operating sounds of the first motor and the second motor, on the condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold.

[0014] Yet another vacuum cleaner according to the present disclosure includes a first rotating brush and a second rotating brush that roll over a floor surface to scrape off dust from the floor surface, the drive device described above, a dust storage unit that stores the dust scraped off by the first rotating brush and the second rotating brush, and a dust accumulation detection unit that detects the amount of dust in the dust storage unit. When the application control unit detects that the amount of dust in the dust storage unit has exceeded a predetermined dust accumulation threshold, the application control unit controls the first voltage application unit and the second voltage application unit to suppress fluctuations in the current values ​​to the first motor and the second motor and to generate a discordant sound from the operating sounds of the first motor and the second motor.

[0015] Yet another vacuum cleaner according to the present disclosure includes first and second rotating brushes that roll over a floor surface to scrape off dust from the floor surface, the drive device described above, a dust storage unit that stores the dust scraped by the first and second rotating brushes, and a dust detection unit that detects the amount of dust scraped by the first and second rotating brushes. The application control unit controls the first and second voltage application units to suppress fluctuations in the current values ​​applied to the first and second motors and to produce a consonant sound from the operating sounds of the first and second motors, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

[0016] Another driving device according to the present disclosure is configured to drive a rotating brush that rolls on a floor surface to scrape dust off the floor surface, or a rotating blade configured to generate a suction force for sucking in dust as it rotates. The driving device includes a motor having a rotor that rotates the rotating brush or the rotating blade, and a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in the magnetic field within the motor at a frequency corresponding to the frequency of the voltage applied to the motor. The motor is configured such that the rotor rotates at a speed corresponding to a current value that is the time average value of a direct current flowing through the motor as a result of the intermittent application of the voltage to the motor, and vibrates in response to the periodic change in the magnetic field at a frequency corresponding to the applied frequency, thereby emitting an operating sound. The driving device further includes an application control unit that controls the voltage application unit so that the applied frequency increases or decreases in accordance with the pitch of the notes on a predetermined musical score, while suppressing fluctuations in the current value. [Effects of the Invention]

[0017] The above-described technology can change the operating noise of the vacuum cleaner while suppressing changes in the performance of the vacuum cleaner. [Brief explanation of the drawings]

[0018] [Figure 1] Vertical cross-sectional view of a vacuum cleaner (first embodiment) [Figure 2] Front view of a vacuum cleaner [Figure 3] Schematic diagram of the internal structure of a vacuum cleaner motor [Figure 4] Diagram showing the DC current input to the motor [Figure 5] Functional configuration diagram of the control circuit that controls the motor [Figure 6] Vertical cross-sectional view of a vacuum cleaner (second embodiment) [Figure 7] Functional diagram of the control circuit that controls the vacuum cleaner motor [Figure 8] Vertical cross-sectional view of a vacuum cleaner (third embodiment) [Figure 9] Functional diagram of the control circuit that controls the vacuum cleaner motor [Figure 10] A musical score representing a melody that could be played by the sound of a vacuum cleaner operating [Figure 11] Schematic diagram showing the structure of a suction nozzle of a vacuum cleaner (fourth embodiment) [Figure 12] Exploded perspective view of the suction nozzle [Figure 13] Functional configuration diagram of the control circuit that controls the suction nozzle motor [Figure 14] Functional configuration diagram of the control circuit that controls the suction nozzle motor [Figure 15] Functional configuration diagram of the control circuit that controls the suction nozzle motor [Figure 16] Functional configuration diagram of the control circuit that controls the suction nozzle motor DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, first to fourth embodiments of the vacuum cleaner will be described in detail with reference to the drawings. However, to facilitate understanding by those skilled in the art, for example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0020] (First embodiment) In the first embodiment, the drive device is incorporated into a vacuum cleaner and is used to generate suction force for sucking up dust.

[0021] (Overall structure of the vacuum cleaner) Fig. 1 is a schematic cross-sectional view of a stick-type vacuum cleaner 100. Fig. 2 is a front view of the vacuum cleaner 100. The vacuum cleaner 100 will be described with reference to Figs. 1 and 2.

[0022] The vacuum cleaner 100 comprises a suction nozzle 130 that sucks up dust on the floor, a vacuum cleaner body 110 attached to the suction nozzle 130 so as to be tiltable back and forth relative to the suction nozzle 130, and a grip 140 extending upward from an upper end 112 of the vacuum cleaner body 110. The vacuum cleaner body 110 and the grip 140 shown in Figures 1 and 2 are in an upright position relative to the suction nozzle 130. When the vacuum cleaner 100 is in use, the vacuum cleaner body 110 and the grip 140 are held by the user in a position tilted backward relative to the suction nozzle 130.

[0023] Suction nozzle 130 is equipped with nozzle case 132 that is wider than vacuum cleaner body 110 so as to form wide suction space 131 into which dust on the floor flows. Suction space 131 opens toward the floor at the front portion of nozzle case 132. Behind this opening, suction space 131 is closed by bottom 134 of nozzle case 132. A rotating brush 133 that is rotatably held by nozzle case 132 is disposed in suction space 131, and rotating brush 133 is exposed from nozzle case 132 through the opening of suction space 131 so as to be able to come into contact with the floor surface.

[0024] Vacuum cleaner main body 110 has a cylindrical housing 111 that is elongated in the vertical direction. The upper part of housing 111 tapers toward upper end 112 of housing 111, and grip part 140 extends upward from upper end 112. Grip part 140 is a rod-shaped part that is thick enough to be gripped by a user. As shown in FIG. 2, grip part 140 is provided with an operating part 141 that is operated by the user.

[0025] Housing 111 is configured to house various components for sucking up dust on the floor surface and storing the sucked up dust. More specifically, as shown in FIG. 1, a suction pipe 113 extending in the vertical direction is disposed inside the lower part of housing 111. A check valve 114 is attached to the upper end of this suction pipe 113. Check valve 114 shown in FIG. 1 closes the upper end of suction pipe 113, but can rotate upward when subjected to an upward external force. When check valve 114 rotates upward, the upper end of suction pipe 113 is opened.

[0026] The lower end of the suction tube 113 is connected to the rear of the suction nozzle 130. The connection between the suction tube 113 and the suction nozzle 130 is configured to allow the suction tube 113 to tilt rearward together with the vacuum cleaner body 110 from the upright position (the position shown in FIG. 1). When the suction tube 113 and the vacuum cleaner body 110 are in the upright position, the lower end of the suction tube 113 abuts against the bottom 134 of the nozzle case 132. That is, when the suction tube 113 and the vacuum cleaner body 110 are in the upright position, the lower end of the suction tube 113 is closed by the bottom 134 of the nozzle case 132. When the vacuum cleaner body 110 tilts rearward from the upright position, the lower end of the suction tube 113 moves in the direction indicated by arrow A in FIG. 1. As a result, the flow path in the suction tube 113 is connected to the suction space 131 of the nozzle case 132.

[0027] The space above suction tube 113 is divided into upper and lower sections by filter section 115. In the following description, the space below filter section 115 will be referred to as "dust storage chamber 152." In addition, in the following description, the space above filter section 115 will be referred to as "drive chamber 153." The portion of housing 111 that constitutes drive chamber 153 will be referred to as "motor accommodating section 172."

[0028] Drive chamber 153 is provided with rotating blades 143 that generate a suction force for sucking in dust. Rotation of rotating blades 143 generates an upward suction force. This suction force causes check valve 114 at the upper end of suction pipe 113 to rotate upward, opening the opening at the upper end of suction pipe 113. In this state, a suction airflow is generated that flows from the floor surface through suction nozzle 130 and suction pipe 113 into dust storage chamber 152, and dust on the floor surface is carried by this suction airflow into dust storage chamber 152. The suction airflow then passes through filter unit 115 and flows into drive chamber 153, while dust contained in this suction airflow is captured by filter unit 115 and retained in dust storage chamber 152.

[0029] A drive device 101 that drives the rotary vanes 143 is configured inside the drive chamber 153. The drive device 101 has a motor 142 that drives the rotary vanes 143 to rotate, and a control circuit 170 that controls the motor 142. The drive chamber 153 also has a storage battery 117 that stores power for the motor 142. The storage battery 117 is electrically connected to the motor 142 via the control circuit 170, and the power of the storage battery 117 is supplied to the motor 142 via the control circuit 170.

[0030] A so-called brushed motor can be used as the motor 142. For example, as shown in Fig. 3, the motor 142 has a substantially cylindrical motor case 121 and a motor shaft 122 that protrudes from the motor case 121 and is rotatably held by the motor case 121. Rotating blades 143 are fixed to the tip of the motor shaft 122. Electrodes 123 and 124 to which a voltage output from the storage battery 117 is applied are fixed to the outer surface of the motor case 121. The voltage applied from the storage battery 117 to the electrodes 123 and 124 is substantially constant.

[0031] 4, a rotor 125, permanent magnets 126 and 127, and brushes 128 and 129 are arranged inside the motor case 121. The permanent magnets 126 and 127 are fixed to the inner surface of the motor case 121 in positions facing each other. The permanent magnet 126 constitutes one of the south pole and the north pole, and the permanent magnet 127 constitutes the other of the south pole and the north pole.

[0032] Rotor 125 is fixed to motor shaft 122, and when rotor 125 rotates, rotating blades 143 attached to the tip of motor shaft 122 can rotate together with motor shaft 122. Rotor 125 has commutators 161 to 163 fixed to motor shaft 122 at intervals in the circumferential direction of motor shaft 122, and coils 164 to 166 connected to these commutators 161 to 163.

[0033] The brushes 128 and 129 are arranged so as to be in contact with at least two of the commutators 161-163 while the rotor 125 and the motor shaft 122 are rotating. The brushes 128 and 129 are electrically connected to the electrodes 123 and 124 shown in FIG. 3. When a voltage is applied from the storage battery 117 to the electrodes 123 and 124, a direct current flows sequentially through the brushes 128 and 129, the commutators 161-163, and the coils 164-166. When the direct current flows through the coils 164-166, a magnetic field is generated from the coils 164-166. The rotor 125 and the motor shaft 122 rotate due to the magnetic force relationship generated between the magnetic field generated from the coils 164-166 and the magnetic field of the permanent magnets 126 and 127.

[0034] When a voltage is applied intermittently from the storage battery 117 to the electrodes 123 and 124, a direct current flows intermittently through the coils 164 to 166. In this case, a state in which a magnetic field is generated from the coils 164 to 166 and a state in which no magnetic field is generated from the coils 164 to 166 are alternately generated at a frequency corresponding to the frequency of the voltage applied to the electrodes 123 and 124. The direction and / or magnitude of the magnetic force that the rotor 125 receives differs between the state in which a magnetic field is generated from the coils 164 to 166 and the state in which no magnetic field is generated from the coils 164 to 166. Therefore, when a direct current flows intermittently through the coils 164 to 166, the direction and / or magnitude of the magnetic force that the rotor 125 receives changes periodically at a frequency corresponding to the frequency of the voltage applied to the electrodes 123 and 124. The periodic change in the magnetic force that the rotor 125 receives causes the rotor 125 and the motor shaft 122 to vibrate. This vibration causes an operating noise to be generated from the motor 142. The frequency of this operating noise varies with changes in the frequency of the voltage applied to the electrodes 123 and .

[0035] A voltage is applied to the electrodes 123, 124, for example, in the application pattern shown in Fig. 5(a) or Fig. 5(b). The magnitude of the voltage applied to the electrodes 123, 124 is the same in the application patterns shown in Fig. 5(a) and Fig. 5(b), but the application frequency of the voltage shown in Fig. 5(a) is lower than the application frequency of the voltage shown in Fig. 5(b). When a voltage is applied to the electrodes 123, 124 in the application pattern shown in Fig. 5(a), the motor 142 generates an operating noise that is lower than when a voltage is applied to the electrodes 123, 124 in the application pattern shown in Fig. 5(b).

[0036] The sum of the areas of the pulses shown in FIG. 5(a) and the sum of the areas of the pulses shown in FIG. 5(b) are equal to each other. That is, the time-averaged value of the DC current (hereinafter referred to as the "current value") flowing through the motor 142 while the voltage is being intermittently applied to the electrodes 123 and 124 is the same between the application patterns shown in FIG. 5(a) and 5(b). Under these conditions, the motor 142 is configured so that the rotation speed of the rotor 125 and the motor shaft 122 does not fluctuate, regardless of whether the voltage application pattern to the electrodes 123 and 124 is switched. Note that if the current value of the DC current flowing through the motor 142 changes in response to the application of voltage to the electrodes 123 and 124, the rotation speed of the rotor 125 and, therefore, the rotating blades 143 also change, causing fluctuations in the suction performance of the vacuum cleaner 100. In order to suppress such fluctuations in suction performance, a voltage is applied intermittently to the electrodes 123 and 124 so as to suppress fluctuations in the current value. In order to apply the voltage in this manner, in this embodiment, the voltage application pattern is switched between the application pattern of FIG. 5(a) and the application pattern of FIG. 5(b).

[0037] The control circuit 170 is configured to change the voltage application pattern to the motor 142 from the application pattern shown in FIG. 5(a) to the application pattern shown in FIG. 5(b) when the remaining amount of power stored in the storage battery 117 falls below a predetermined power threshold. In detail, as shown in FIG. 6, the control circuit 170 forms part of a power supply circuit 167 for supplying power from the storage battery 117 to the motor 142, and has a voltage application unit 168 configured to open and close the power supply circuit 167. When the voltage application unit 168 closes the power supply circuit 167, a voltage is applied to the electrodes 123 and 124 of the motor 142. On the other hand, when the voltage application unit 168 opens the power supply circuit 167, no voltage is applied to the electrodes 123 and 124.

[0038] The control circuit 170 further includes an application control unit 169 that controls the voltage application unit 168, and a power detection unit 171 that detects the remaining amount of power stored in the storage battery 117. The application control unit 169 is electrically connected to the operation unit 141, and when a user operates the operation unit 141 to instruct the motor 142 to operate, the application control unit 169 controls the voltage application unit 168 to repeatedly open and close the power supply circuit 167. The repeated opening and closing of the power supply circuit 167 by the voltage application unit 168 causes the magnetic field within the motor 142 to change periodically, causing the rotor 125 of the motor 142 to vibrate. At this time, if the remaining amount of power in the storage battery 117 detected by the power detection unit 171 exceeds the power threshold, the application control unit 169 controls the voltage application unit 168 to obtain the application pattern shown in FIG. 5(a). On the other hand, when the remaining power of the storage battery 117 detected by the power detection unit 171 is below the power threshold, the application control unit 169 controls the voltage application unit 168 so as to obtain the application pattern shown in FIG. 5(b).

[0039] (Vacuum cleaner operation) The operation of the vacuum cleaner 100 when the user starts cleaning work while the storage battery 117 stores power exceeding the power threshold will be described below.

[0040] During cleaning work, the user holds the vacuum cleaner 100 in a position where the vacuum cleaner body 110 and the grip part 140 are tilted backward relative to the suction nozzle 130. By tilting the vacuum cleaner body 110 and the grip part 140 backward relative to the suction nozzle 130, it becomes easier to move the suction nozzle 130 forward while pushing it. In this state, the flow path of the suction tube 113 communicates with the suction space 131 of the suction nozzle 130.

[0041] When the user subsequently performs an operation on the operation unit 141 to start the vacuum cleaner 100, the voltage application control unit 169 controls the voltage application unit 168 to obtain the application pattern shown in FIG. 5(a). At this time, the motor 142 drives the rotary blades 143 at a rotation speed corresponding to the current value (the time average value of the DC current flowing through the motor 142) in the application pattern shown in FIG. 5(a). In this case, the frequency of the voltage applied to the motor 142 is low, so the rotor 125 of the motor 142 vibrates at a low frequency. As a result, the motor 142 emits a low-frequency operating sound.

[0042] When a voltage is applied to the motor 142, the rotor 125 of the motor 142 rotates. Then, the rotary vanes 143 connected to the rotor 125 also rotate with the rotation of the rotor 125. The rotation of the rotary vanes 143 generates an upward suction force. This suction force rotates the check valve 114 upward, and the upper end of the suction pipe 113 opens.

[0043] When the upper end of suction pipe 113 is opened, an upward suction airflow is generated, and this suction airflow flows into dust storage chamber 152 through suction space 131 of suction nozzle 130 and the flow path of suction pipe 113. Dust on the floor surface is carried by this suction airflow and flows into dust storage chamber 152. Filter unit 115 allows the suction airflow to flow into drive chamber 153, while dust contained in the suction airflow is captured by filter unit 115. This dust may be adsorbed to the lower surface of filter unit 115 while rotary vane 143 is rotating.

[0044] As the motor 142 operates, the remaining amount of power stored in the storage battery 117 decreases. When the power detection unit 171 detects that the remaining amount has fallen below the power threshold, the application control unit 169 controls the voltage application unit 168 so that a voltage is applied to the motor 142 according to the application pattern shown in FIG. 5(b). The time average value of the DC current flowing through the motor 142 when a voltage is applied to the motor 142 according to the application pattern shown in FIG. 5(b) is the same as the time average value of the DC current flowing through the motor 142 when a voltage is applied to the motor 142 according to the application pattern shown in FIG. 5(a). Therefore, the rotation speed of the rotary vanes 143, which are rotationally driven by the motor 142, hardly changes even when the voltage application pattern is switched from that shown in FIG. 5(a) to that shown in FIG. 5(b).

[0045] 5(b) 。 As the voltage application pattern is switched from the application pattern shown in Figure 5(a) to the application pattern shown in Figure 5(b), the frequency of the voltage applied to the motor 142 increases, causing the rotor 125 of the motor 142 to vibrate at a high frequency. As a result, the operating sound of the motor 142 changes from a low pitch to a high pitch. This change in the operating sound of the motor 142 allows the user to recognize that the remaining power of the storage battery 117 is getting low.

[0046] In the vacuum cleaner 100 of the first embodiment, if a cleaning operation is started when the remaining power of the storage battery 117 is above the power threshold, the user can recognize that the remaining power of the storage battery 117 is low due to a change in the operating sound of the motor 142. If the user starts a cleaning operation when the remaining power of the storage battery 117 is below the power threshold, a high-frequency operating sound is emitted from the motor 142 at the start of the cleaning operation. This high-frequency operating sound then enables the user to recognize that the remaining power of the storage battery 117 is low.

[0047] In the vacuum cleaner 100 of the first embodiment, even if the pattern of voltage application to the motor 142 is changed, there is almost no change in the current value of the direct current flowing through the motor 142 (i.e., the time average value of the direct current). For this reason, whether the pattern of voltage application to the motor 142 is the application pattern shown in Fig. 5(a) or the application pattern shown in Fig. 5(b), there is almost no change in the rotation speed of the rotor 125 of the motor 142, and therefore the rotating blades 143. Therefore, the operating noise of the motor 142 can be changed without causing almost any change in the suction force associated with the rotation of the rotating blades 143.

[0048] In the vacuum cleaner 100 of the first embodiment, the voltage application pattern to the motor 142 is changed from the application pattern shown in Fig. 5(a) to the application pattern shown in Fig. 5(b). Conversely, the application control unit 169 may control the voltage application unit 168 so that the voltage application pattern to the motor 142 is changed from the application pattern shown in Fig. 5(b) to the application pattern shown in Fig. 5(a). In this case, when the remaining power of the storage battery 117 falls below the power threshold, the operating sound of the motor 142 changes from a high-pitched to a low-pitched sound.

[0049] When the motor 142 is fixed to the housing 111 so that vibrations of the rotor 125 of the motor 142 are transmitted to the motor housing 172, a state of resonance may be generated between the motor housing 172 and the rotor 125 of the motor 142. In this case, in order to obtain this state of resonance, control may be performed to bring the frequency of the voltage applied to the motor 142 closer to the resonance frequency of the motor housing 172 after the remaining amount of power in the storage battery 117 falls below the power threshold.

[0050] That is, before the remaining amount of power in the storage battery 117 falls below the power threshold, the application control unit 169 controls the voltage application unit 168 so that the power supply circuit 167 is opened and closed at a frequency that is away from the resonance frequency of the motor housing unit 172. In this case, a resonance state between the motor housing unit 172 and the motor 142 does not occur, and even if vibrations of the motor 142 are transmitted to the motor housing unit 172, the motor housing unit 172 vibrates with a small vibration amplitude.

[0051] Thereafter, when the remaining power of the storage battery 117 falls below the power threshold, the application control unit 169 controls the voltage application unit 168 so that the power supply circuit 167 is opened and closed at a frequency close to the resonance frequency of the motor housing 172. In this case, the motor housing 172 and the motor 142 resonate, increasing the vibration amplitude of the motor housing 172 and, in turn, the operating noise emitted from the motor housing 172. Therefore, the user can recognize from this increase in operating noise that the remaining power of the storage battery 117 is getting low. Furthermore, since an increase in the operating noise of the vacuum cleaner 100 can be unpleasant for the user, the increase in the operating noise of the vacuum cleaner 100 can prompt the user to stop the vacuum cleaner 100.

[0052] (Second embodiment) The vacuum cleaner 100 of the first embodiment is configured so that the operating sound of the motor 142 changes when the power stored in the storage battery 117 becomes low. In contrast, the vacuum cleaner 100 of the second embodiment is configured so that the operating sound of the motor 142 changes when the amount of dust stored in the dust storage chamber 152 exceeds a predetermined dust storage threshold. In this case, the vacuum cleaner 100 may have a dust storage detection unit 173 that detects the amount of dust stored in the dust storage chamber 152, as shown in Fig. 7. The dust storage detection unit 173 may be configured by a transmission-type optical sensor provided at the bottom of the dust storage chamber 152.

[0053] When there is little dust in dust storage chamber 152, most of the dust is attracted to the underside of filter unit 115 by the suction force generated by the rotation of rotary blades 143 while motor 142 is operating. However, when the amount of dust in dust storage chamber 152 increases, some of the dust falls from the underside of filter unit 115 and may block the optical path of dust storage detection unit 173. At this time, dust storage detection unit 173 outputs a signal indicating that dust exceeding the dust storage threshold is present in dust storage chamber 152.

[0054] The control circuit 170 can be configured as shown in Fig. 8 so that the voltage application pattern to the motor 142 changes in response to a signal from the dust accumulation detection unit 173. That is, the dust accumulation detection unit 173 is electrically connected to the application control unit 169 of the control circuit 170. The application control unit 169 is configured to change the voltage application pattern to the motor 142 from the application pattern shown in Fig. 5(a) to the application pattern shown in Fig. 5(b) in response to a signal from the dust accumulation detection unit 173.

[0055] When a user starts cleaning when there is not much dust accumulated in dust storage chamber 152, application control unit 169 controls voltage application unit 168 to obtain the application pattern shown in Fig. 5(a). In this state, motor 142 generates a relatively low operating noise. Thereafter, when the amount of dust in dust storage chamber 152 increases and the dust in dust storage chamber 152 blocks the optical path of dust accumulation detection unit 173, a signal is output from dust accumulation detection unit 173. In response to this signal, application control unit 169 controls voltage application unit 168 to switch the voltage application pattern to motor 142 to the application pattern shown in Fig. 5(b).

[0056] This switching of the application pattern changes the operating sound of motor 142 from a low tone to a high tone, and this change in sound enables the user to recognize that there is an increase in dust in dust storage chamber 152. On the other hand, this switching of the application pattern causes almost no change in the current value of the DC current flowing through motor 142 (i.e., the time average value of the DC current), and therefore almost no change in the rotation speed of rotor 125, and therefore of rotary vanes 143. As a result, changes in suction force are suppressed.

[0057] In the vacuum cleaner 100 of the second embodiment, the voltage application pattern to the motor 142 is changed from the application pattern shown in Fig. 5(a) to the application pattern shown in Fig. 5(b). Conversely, the application control unit 169 may control the voltage application unit 168 so that the voltage application pattern to the motor 142 is changed from the application pattern shown in Fig. 5(b) to the application pattern shown in Fig. 5(a). In this case, when the dust accumulation detection unit 173 detects that the amount of dust accumulated in the dust storage chamber 152 has exceeded a predetermined dust accumulation threshold, the operating sound of the motor 142 changes from a high-pitched to a low-pitched sound.

[0058] If motor 142 is fixed to housing 111 so that vibrations of rotor 125 of motor 142 are transmitted to motor housing 172, the user may be notified that dust accumulation detection unit 173 has detected an amount of dust exceeding the dust accumulation threshold by also using vibrations of motor housing 172. That is, the frequency of the voltage applied after dust accumulation detection unit 173 has detected an amount of dust exceeding the dust accumulation threshold may be set to be close to the resonant frequency of motor housing 172. In this case, when dust accumulation detection unit 173 has not detected that the amount of dust accumulated in dust storage chamber 152 has exceeded the predetermined dust accumulation threshold, the vibration amplitude of motor housing 172 accompanying the transmission of vibrations from motor 142 to motor housing 172 is relatively small. On the other hand, when dust accumulation detection unit 173 detects that the amount of dust accumulated in dust storage chamber 152 has exceeded the predetermined dust accumulation threshold, the vibration amplitude of motor housing 172 accompanying the transmission of vibrations from motor 142 to motor housing 172 increases. This can increase the operating noise of the vacuum cleaner 100 due to vibration of the motor housing 172. Therefore, the user can perceive an increase in the operating noise of the vacuum cleaner 100 as an increase in the amount of dust in the dust storage chamber 152. Furthermore, since the increase in the operating noise of the vacuum cleaner 100 can be unpleasant for the user, the increase in the operating noise of the vacuum cleaner 100 can prompt the user to stop the vacuum cleaner 100.

[0059] (Third embodiment) The vacuum cleaner 100 of the second embodiment changes the operating sound of the motor 142 when the amount of dust in the dust storage chamber 152 exceeds the dust accumulation threshold. Alternatively, the vacuum cleaner 100 may be configured to change the operating sound of the motor 142 depending on whether the amount of dust flowing into the dust storage chamber 152 is large or small. In this case, the user can recognize whether they are cleaning an area with a lot of dust or an area with little dust, based on the operating sound of the motor 142.

[0060] To detect whether the amount of dust flowing into dust storage chamber 152 is large or small, vacuum cleaner 100 shown in FIG. 9 has dust detection unit 181 that forms an optical path that crosses the flow path of suction tube 113. Dust detection unit 181 may be configured, for example, as a transmission-type optical sensor provided in suction tube 113. In this case, when there is a large amount of dust on the floor, the optical path of dust detection unit 181 is blocked more frequently. Conversely, when there is little dust on the floor, the optical path of dust detection unit 181 is blocked less frequently. Dust detection unit 181 may be configured to output a signal when the optical path is blocked.

[0061] 10, the control circuit 170 can be configured so that the pattern of voltage application to the motor 142 changes depending on the frequency of signal input from the dust detection unit 173. That is, the dust detection unit 181 is electrically connected to the application control unit 169 of the control circuit 170, and the application control unit 169 is configured to receive the signal output from the dust detection unit 181. In this case, by setting a predetermined threshold value for the frequency of signal input to the dust detection unit 181, this threshold value can be used as a dust threshold value for determining whether there is a lot or a little dust on the floor surface.

[0062] When the frequency of signal input from dust accumulation detection unit 173 is below the dust threshold, application control unit 169 controls voltage application unit 168 to obtain the application pattern shown in FIG. 5(a). In this case, a low operating sound is emitted from motor 142. Conversely, when the frequency of signal input from dust accumulation detection unit 173 is above the dust threshold, application control unit 169 controls voltage application unit 168 to obtain the application pattern shown in FIG. 5(b). In this case, a high operating sound is emitted from motor 142. When such control is performed, the user can determine whether the area they are cleaning is dusty or dusty based on the level of the operating sound from motor 142. When motor 142 is emitting a high operating sound, the user can stay in place and continue cleaning until the motor 142 emits a low operating sound.

[0063] Regardless of changes in the operating noise of the motor 142, the motor 142 can maintain a substantially constant rotation speed of the rotary vanes 143. Therefore, the suction force of the rotary vanes 143 is also maintained substantially constant.

[0064] In the vacuum cleaner 100 of the third embodiment, when a large amount of dust flows into the dust storage chamber 152, the operating noise of the motor 142 becomes louder, and when a small amount of dust flows into the dust storage chamber 152, the operating noise of the motor 142 becomes quieter. Conversely, the vacuum cleaner 100 may be configured so that when a large amount of dust flows into the dust storage chamber 152, the motor 142 generates a quiet operating noise, and when a small amount of dust flows into the dust storage chamber 152, the motor 142 generates a loud operating noise.

[0065] The vacuum cleaner 100 of the first to third embodiments changes the operating sound of the motor 142 to notify the user of the state of the vacuum cleaner 100 (i.e., the amount of stored power or the amount of dust) or whether the area being cleaned by the vacuum cleaner 100 has a lot or a little dust. Alternatively, the vacuum cleaner 100 may be configured to play a melody with the operating sound of the motor 142. For example, the application control unit 169 of the vacuum cleaner 100 may control the voltage application unit 168 so that the frequency of the voltage applied to the motor 142 increases or decreases in accordance with the pitch of the notes shown on the musical score shown in FIG. 11 . In this case, the operating sound of the motor 142 plays a melody, so that the user can perform cleaning work while listening to the operating sound of the motor 142 as music.

[0066] In the vacuum cleaner 100 of the first embodiment, when the remaining power of the storage battery 117 falls below a power threshold, the voltage application pattern to the motor 142 is switched from the application pattern shown in FIG. 5(a) to the application pattern shown in FIG. 5(b). In the vacuum cleaner 100 of the second embodiment, when the amount of dust in the dust storage chamber 152 exceeds a dust storage threshold, the voltage application pattern to the motor 142 is switched from the application pattern shown in FIG. 5(a) to the application pattern shown in FIG. 5(b). In the vacuum cleaner 100 of the third embodiment, when the amount of dust flowing into the dust storage chamber 152 exceeds the dust threshold, the voltage application pattern to the motor 142 is switched from the application pattern shown in FIG. 5(a) to the application pattern shown in FIG. 5(b). However, the conditions for changing the voltage application pattern to the motor 142 are not limited to these, and the voltage application pattern to the motor 142 may be changed when other conditions are satisfied.

[0067] In the vacuum cleaner 100 of the first to third embodiments, a brushed motor is used as the motor 142. Alternatively, other types of motors may be used as the motor 142 as long as the rotation speed of the rotor is maintained regardless of changes in the applied frequency of the voltage, while the vibration frequency of the rotor, and therefore the operating noise from the rotor, changes with changes in the applied frequency of the voltage.

[0068] (Fourth embodiment) The driving device 101 of the vacuum cleaner 100 according to the first to third embodiments changes the operating noise of the motor 142 that rotates the rotary blades 143. Alternatively, the driving device 101 may be configured to change the operating noise of another motor included in the vacuum cleaner 100.

[0069] For example, as shown in Fig. 12, the driving device 101 may be configured to rotate a first rotating brush 135 and a second rotating brush 136 provided in the suction space 131 of the suction nozzle 130. In this case, the driving device 101 may be configured using a first motor 137 and a second motor 138 provided at the rear of the nozzle case 132. The structures of the first motor 137 and the second motor 138 are the same as those of the motor 142 shown in Figs. 3 and 4.

[0070] A portion of the first rotating brush 135 and the second rotating brush 136 protrudes downward through the opening of the suction space 131 so as to come into contact with the floor surface. When the first rotating brush 135 and the second rotating brush 136 are rotated by the first motor 137 and the second motor 138, they can scrape off dust on the floor surface.

[0071] Nozzle case 132 has a generally C-shape that opens forward in plan view. Specifically, nozzle case 132 has a motor housing section 139 that houses first motor 137 and second motor 138, and a first protrusion 154 and a second protrusion 155 that protrude forward from the left and right ends of motor housing section 139, respectively. Motor housing section 139 defines the rear end of suction space 131. Furthermore, first protrusion 154 defines the left end of suction space 131, and second protrusion 155 defines the right end of suction space 131.

[0072] The first protruding portion 154 rotatably supports the first rotating brush 135 in a cantilevered manner. The second protruding portion 155 rotatably supports the second rotating brush 136 in a cantilevered manner. As shown in Fig. 13, a nozzle cover 156 is placed over the first rotating brush 135 and the second rotating brush 136. The nozzle cover 156 is configured to define the upper end and front end of the suction space 131.

[0073] The first motor 137 is connected to the first rotating brush 135 via a drive belt 201 that extends between the first protrusion 154 and the left end portion of the motor accommodating portion 139. Rotation of a first rotor (same as rotor 125 shown in FIG. 4) of the first motor 137 is transmitted to the first rotating brush 135 via the drive belt 201. The second motor 138 is connected to the second rotating brush 136 via a drive belt 202 that extends between the second protrusion 155 and the right end portion of the motor accommodating portion 139. Rotation of a second rotor (same as rotor 125 shown in FIG. 4) of the second motor 138 is transmitted to the second rotating brush 136 via the drive belt 202.

[0074] The control circuit 210 that controls the first motor 137 and the second motor 138 may be configured as shown in Fig. 14. The control circuit 210 may be disposed inside the nozzle case 132 or inside the housing 111.

[0075] 14, the control circuit 210 forms a part of a first supply circuit 211 for supplying power from the storage battery 117 to the first motor 137, and a part of a second supply circuit 212 for supplying power from the storage battery 117 to the second motor 138. A first voltage application unit 213 for opening and closing the first supply circuit 211 is provided on the first supply circuit 211, and a second voltage application unit 214 for opening and closing the second supply circuit 212 is provided on the second supply circuit 212.

[0076] 6 , the control circuit 210 includes an application control unit 169 and a power detection unit 171. While the remaining power of the storage battery 117 is above the power threshold, the application control unit 169 controls the first voltage application unit 213 and the second voltage application unit 214 so that the operating sounds of the first motor 137 and the second motor 138 produce a consonant sound. For example, the application control unit 169 may control the first voltage application unit 213 and the second voltage application unit 214 so that one of the first motor 137 and the second motor 138 produces the sound of "do" and the other produces the sound of "mi." Alternatively, the application control unit 169 may control the first voltage application unit 213 and the second voltage application unit 214 so that one of the first motor 137 and the second motor 138 produces the sound of "mi" and the other produces the sound of "so."

[0077] Conversely, while the remaining power of the storage battery 117 is below the power threshold, the application control unit 169 controls the first voltage application unit 213 and the second voltage application unit 214 so that the operating sounds of the first motor 137 and the second motor 138 produce a discordant sound. For example, the application control unit 169 may control the first voltage application unit 213 and the second voltage application unit 214 so that one of the first motor 137 and the second motor 138 produces the sound of "do" and the other produces the sound of "re." Alternatively, the application control unit 169 may control the first voltage application unit 213 and the second voltage application unit 214 so that one of the first motor 137 and the second motor 138 produces the sound of "si" and the other produces the sound of "do."

[0078] When the first voltage application unit 213 and the second voltage application unit 214 are controlled in this manner, if the remaining power of the storage battery 117 is above the power threshold, the operating sounds of the first motor 137 and the second motor 138 become consonant, and the user is unlikely to find these operating sounds unpleasant. On the other hand, if the remaining power of the storage battery 117 falls below the power threshold, the operating sounds of the first motor 137 and the second motor 138 become discordant, and the user may find these operating sounds unpleasant. Furthermore, the operating sounds of the first motor 137 and the second motor 138 unpleasant to the user may prompt the user to stop cleaning.

[0079] When vacuum cleaner 100 has dust accumulation detection unit 173 as shown in Fig. 7, control circuit 210 may be configured as shown in Fig. 15. In this case, while dust accumulation detection unit 173 detects an amount of dust below the dust accumulation threshold, application control unit 169 controls first voltage application unit 213 and second voltage application unit 214 so that the operating sounds of first motor 137 and second motor 138 produce a consonant sound. In this case, while the amount of dust in dust storage chamber 152 is below the dust accumulation threshold, the user can continue cleaning without feeling uncomfortable by the operating sounds of first motor 137 and second motor 138.

[0080] On the other hand, when dust accumulation detection unit 173 detects an amount of dust exceeding the dust accumulation threshold, application control unit 169 controls first voltage application unit 213 and second voltage application unit 214 so that the operating sounds of first motor 137 and second motor 138 create a discordant sound. In this case, when the amount of dust in dust storage chamber 152 exceeds the dust accumulation threshold, the user may find the operating sounds of first motor 137 and second motor 138 unpleasant. This can encourage the user to stop cleaning when there is a lot of dust in dust storage chamber 152.

[0081] When vacuum cleaner 100 has dust detection unit 181 as shown in Fig. 9, control circuit 210 may be configured as shown in Fig. 16. In this case, while dust detection unit 181 detects an amount of dust exceeding the dust threshold, application control unit 169 controls first voltage application unit 213 and second voltage application unit 214 so that the operating sounds of first motor 137 and second motor 138 produce a consonant sound. In this case, while dust detection unit 181 detects that the amount of dust passing through suction tube 113 exceeds the dust threshold, the user can continue cleaning without feeling uncomfortable by the operating sounds of first motor 137 and second motor 138.

[0082] On the other hand, when the dust detection unit 181 detects an amount of dust below the dust threshold, the application control unit 169 controls the first voltage application unit 213 and the second voltage application unit 214 so that the operating sounds of the first motor 137 and the second motor 138 create a discordant sound. In this case, when the amount of dust passing through the suction tube 113 falls below the dust threshold, the user finds the operating sounds of the first motor 137 and the second motor 138 unpleasant. This may encourage the user to clean another area. If there is a lot of dust in this area, the operating sounds of the first motor 137 and the second motor 138 create a consonant sound. In this state, the user can continue cleaning this area without finding the operating sounds of the first motor 137 and the second motor 138 unpleasant.

[0083] In the vacuum cleaner 100 of the fourth embodiment, the operating sounds of the first motor 137 and the second motor 138 are changed to notify the user of the state of the vacuum cleaner 100 (amount of stored power or amount of dust) or whether there is a lot of dust in the area being cleaned by the vacuum cleaner 100. Furthermore, while the operating sounds of the first motor 137 and the second motor 138 are changed, changes in the rotation speeds of the first rotating brush 135 and the second rotating brush 136, which are rotationally driven by the first motor 137 and the second motor 138, are suppressed. As a result, changes in the scraping ability to scrape off dust on the floor surface are suppressed.

[0084] 14 to 16 changes the operating sounds of first motor 137 and second motor 138 to notify the user of the state of vacuum cleaner 100 (the amount of stored power or the amount of dust) or whether the area being cleaned by vacuum cleaner 100 has a lot or a little dust. Alternatively, control circuit 210 may control first motor 137 and second motor 138 so that the operating sound of one of first motor 137 and second motor 138 plays the main melody of a predetermined musical score, and the operating sound of the other motor plays the secondary melody. In this case, the user can perform cleaning work while listening to the operating sounds of first motor 137 and second motor 138 as music.

[0085] The control circuit 210 in FIGS. 14 to 16 is configured to change the operating sounds of both the first motor 137 and the second motor 138. Alternatively, the control circuit 210 may be configured to change the operating sound of only one of the first motor 137 and the second motor 138. In this case, the control of this motor may be applied according to the first to third embodiments. When the first embodiment (control based on the remaining power of the storage battery 117) or the second embodiment (control based on the amount of dust stored in the dust storage chamber 152) is applied, the resonance between the first motor 137 or the second motor 138 and the motor housing 139 may be used to notify the user. That is, when the remaining power of the storage battery 117 falls below a power threshold, control may be performed to bring the frequency of the first rotor of the first motor 137 or the second rotor of the second motor 138 closer to the resonant frequency of the motor housing 139. Alternatively, when the amount of dust in dust storage chamber 152 exceeds the dust storage threshold, control may be performed to bring the vibration frequency of rotor 125 of first motor 137 or second motor 138 closer to the resonance frequency of motor housing 139. In these cases, the operating noise emitted from suction nozzle 130 becomes louder, which may prompt the user to suspend cleaning work when the amount of stored power in storage battery 117 is low or when there is a lot of dust in dust storage chamber 152.

[0086] In the vacuum cleaner 100 of the fourth embodiment, when any of the following conditions 1 to 3 is satisfied, the pattern of voltage application to the motor 142 is changed. However, the conditions for changing the pattern of voltage application to the motor 142 are not limited to these, and the pattern of voltage application to the motor 142 may be changed when other conditions are satisfied. (Condition 1) The remaining amount of power in the storage battery 117 is below the power threshold. (Condition 2) The amount of dust in the dust storage chamber 152 exceeds the dust storage threshold. (Condition 3) The amount of dust flowing into the dust storage chamber 152 exceeds the dust threshold.

[0087] In the vacuum cleaner 100 of the fourth embodiment, brushed motors are used as the first motor 137 and the second motor 138. Alternatively, other types of motors may be used as long as the rotation speed of the rotor is maintained regardless of changes in the applied frequency of the voltage, while the vibration frequency of the rotor, and therefore the operating noise from the rotor, changes with changes in the applied frequency of the voltage.

[0088] In the first to fourth embodiments, the vacuum cleaner 100 is a stick type. Alternatively, the control techniques of the first to fourth embodiments may be applied to a canister type vacuum cleaner or a handheld type vacuum cleaner.

[0089] (Effects, etc.) The technology according to the above-described embodiment has the following features and provides the following effects.

[0090] (Technology 1) A drive device according to one aspect of the above-described embodiments is configured to drive a rotating brush that rolls on a floor surface to scrape dust off the floor surface, or a rotating blade configured to generate a suction force to suck in dust as it rotates. The drive device includes a motor having a rotor that rotates the rotating brush or the rotating blade, and a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in the magnetic field within the motor at a frequency corresponding to the frequency of the voltage applied to the motor. The motor is configured so that the rotor rotates at a speed corresponding to a current value that is a time average value of a direct current flowing through the motor as a result of the intermittent application of the voltage to the motor, and vibrates in response to the periodic change in the magnetic field at a frequency corresponding to the applied frequency, thereby emitting an operating sound. The drive device further includes an application control unit that controls the voltage application unit to change the applied frequency while suppressing fluctuations in the current value, provided that a predetermined change condition is satisfied.

[0091] In the above-described configuration, the voltage application unit intermittently applies a voltage of a predetermined magnitude to the motor, periodically alternating between a state in which a direct current is flowing through the motor and a state in which a direct current is not flowing through the motor. The state of the magnetic field within the motor differs between a state in which a direct current is flowing through the motor and a state in which a direct current is not flowing through the motor. Therefore, when the voltage application unit intermittently applies a voltage to the motor, the magnitude and / or direction of the magnetic force received by the rotor periodically changes at a frequency corresponding to the applied frequency of the intermittent voltage application. The periodic change in the magnetic force received by the rotor causes the rotor of the motor to vibrate, and the motor generates an operating sound corresponding to the rotor's vibration frequency. Therefore, if the frequency of the voltage applied to the motor changes, the frequency of the operating sound of the motor also changes. If the frequency of the voltage applied to the motor is changed under the condition that a predetermined change condition is satisfied, the user can recognize that the change condition has been satisfied by the change in the operating sound of the motor.

[0092] When the applied frequency is changed, fluctuations in the current value, which is the time average value of the DC current flowing through the motor, are suppressed. Therefore, even when the applied frequency is changed, fluctuations in the rotation speed of the rotor are suppressed. As a result, fluctuations in the rotation speed of the rotating brush or rotating blades, which are rotated by the rotation of the rotor, are also suppressed. Therefore, changes in the dust scraping performance of the rotating brush or the suction force of the rotating blades are unlikely to occur.

[0093] (Technology 2) A drive device according to another aspect of the above-described embodiments is configured to drive a first rotating brush and a second rotating brush that roll on a floor surface to scrape off dust from the floor surface. The drive device includes a first motor having a first rotor that rotationally drives the first rotating brush, a second motor having a second rotor that rotationally drives the second rotating brush, a first voltage application unit that applies a voltage of a predetermined magnitude to the first motor intermittently to cause a periodic change in the magnetic field in the first motor at a frequency corresponding to the frequency of the voltage applied to the first motor, and a second voltage application unit that applies a voltage of a predetermined magnitude to the second motor intermittently to cause a periodic change in the magnetic field in the second motor at a frequency corresponding to the frequency of the voltage applied to the second motor. The first motor is configured such that a first rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the first motor in response to the intermittent application of a voltage to the first motor, and the first rotor vibrates in response to a periodic change in a magnetic field at a frequency corresponding to the application frequency to the first motor, thereby emitting an operating sound. The second motor is configured such that a second rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the second motor in response to the intermittent application of a voltage to the second motor, and the second rotor vibrates in response to a periodic change in a magnetic field at a frequency corresponding to the application frequency to the second motor, thereby emitting an operating sound. The drive device further includes an application control unit that controls the first voltage application unit and the second voltage application unit. The application control unit controls the first voltage application unit to change the application frequency to the first motor while suppressing fluctuations in the current value to the first motor, provided that a predetermined change condition is satisfied, and controls the second voltage application unit to change the application frequency to the second motor while suppressing fluctuations in the current value to the second motor so that the application frequency to the second motor is different from the application frequency of the voltage to the first motor, thereby generating a discordant or consonant sound from the operating sounds of the first motor and the second motor.

[0094] In the above-described configuration, a voltage of a predetermined magnitude is applied intermittently to each of the first motor and the second motor. While this intermittent voltage application is being performed, the magnitude and / or direction of the magnetic force received by the first rotor of the first motor periodically changes at a frequency corresponding to the application frequency of this intermittent voltage application. The magnitude and / or direction of the magnetic force received by the second rotor of the second motor also periodically changes. The periodic change in the magnetic force received by the first rotor and the second rotor causes these rotors to vibrate. An operating sound corresponding to the vibration frequency of the first rotor is then emitted from the first motor, and an operating sound corresponding to the vibration frequency of the second rotor is emitted from the second motor.

[0095] By making the applied frequency to the first motor and the applied frequency to the second motor different from each other, it is possible to generate a discordant or consonant sound using the operating sounds from the first motor and the second motor. If a discordant sound is generated, the user may find the discordant sound unpleasant and stop cleaning work. If a consonant sound is generated, the user may find the consonant sound pleasant and be encouraged to continue cleaning work. By generating a discordant or consonant sound on the condition that a predetermined change condition is met, it is possible to encourage the user to stop or continue cleaning work when the change condition is met.

[0096] When the frequency of the voltage applied to the first motor and the second motor is changed, fluctuations in the current value, which is the time average value of the DC current flowing through the motor, are suppressed. Therefore, even if the applied frequency is changed, fluctuations in the rotation speed of the first rotor and the second rotor are suppressed. As a result, fluctuations in the rotation speed of the first rotating brush and the second rotating brush, which are rotated by these rotors, are also suppressed. Therefore, changes in the dust scraping performance of these rotating brushes are unlikely to occur.

[0097] (Technology 3) A drive device according to yet another aspect of the above-described embodiments is configured to drive a rotating brush that rolls on a floor surface to scrape dust off the floor surface, or a rotating blade that generates a suction force to suck in dust as it rotates. The drive device includes a motor having a rotor that rotates the rotating brush or the rotating blade, and a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in the magnetic field within the motor at a frequency corresponding to the frequency of the voltage applied to the motor. The motor is configured such that the rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the motor as a result of the intermittent application of the voltage to the motor, and vibrates in response to the periodic change in the magnetic field at a frequency corresponding to the applied frequency, thereby emitting an operating sound. The drive device further includes an application control unit that controls the voltage application unit so that the applied frequency increases or decreases in accordance with the pitch of the notes on a predetermined musical score, while suppressing fluctuations in the current value.

[0098] In the above-described configuration, the voltage application unit applies a voltage to the motor intermittently, causing the magnitude and / or direction of the magnetic force received by the rotor to change periodically at a frequency corresponding to the applied frequency of the intermittent voltage application. The periodic change in the magnetic force received by the rotor causes the rotor of the motor to vibrate, and the motor emits an operating sound corresponding to the rotor's vibration frequency. Therefore, when the frequency of the voltage applied to the motor changes, the frequency of the operating sound of the motor also changes. If this applied frequency increases or decreases in accordance with the pitch of the notes on a predetermined musical score, the operating sound of the motor can produce a melody represented by the notes on the musical score. Therefore, the user can perceive the operating sound of the motor as music.

[0099] While the frequency of the voltage applied to the motor is increased or decreased in accordance with the pitch of the musical note, fluctuations in the current value, which is the time average value of the DC current flowing through the motor, are suppressed. Therefore, even if the applied frequency is changed, fluctuations in the rotation speed of the rotor are suppressed. As a result, fluctuations in the rotation speed of the rotating brush or rotating blades, which are driven to rotate by the rotation of the rotor, are also suppressed. Therefore, changes in the dust scraping performance of the rotating brush or the suction force of the rotating blades are unlikely to occur.

[0100] (Technology 4) The vacuum cleaner according to the above-described embodiment includes a rotating brush that rolls on the floor surface to scrape off dust on the floor surface or a rotating blade configured to generate suction force for sucking in dust while rotating, a drive device described in Technology 1, a storage battery that stores power for the motor, and a power detection unit that detects the remaining amount of power stored in the storage battery. The application control unit controls the voltage application unit to change the application frequency while suppressing fluctuations in the current value, on the condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold.

[0101] In the above configuration, when the remaining power stored in the storage battery falls below a predetermined power threshold, the operating sound of the motor changes. Therefore, the change in the operating sound of the motor can notify the user of the decrease in the power stored in the storage battery and encourage them to charge the storage battery.

[0102] (Technology 5) Another vacuum cleaner according to the above embodiment includes a first rotating brush and a second rotating brush that roll on the floor surface to scrape off dust on the floor surface, a drive device according to Technical Example 2, a storage battery that stores power for the first motor and the second motor, and a power detection unit that detects the remaining amount of power stored in the storage battery. On the condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold, the application control unit controls the first voltage application unit and the second voltage application unit so as to suppress fluctuations in the current values ​​to the first motor and the second motor and to generate a discordant sound by the operating sounds of the first motor and the second motor.

[0103] In the above configuration, when the remaining power stored in the storage battery falls below a predetermined power threshold, a discordant sound is generated between the operating sounds of the first motor and the second motor. If the user finds this discordant sound unpleasant, the user may stop cleaning work. In other words, the user can be prompted to stop cleaning work when the remaining power stored in the storage battery is low.

[0104] (Technology 6) A further vacuum cleaner according to the above-described embodiment includes a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade configured to generate a suction force for sucking in dust as it rotates, a drive device as described in Technology 1, a dust storage unit that stores the dust scraped off by the rotating brush or the dust sucked in by the suction force generated by the rotation of the rotating blade, and a dust storage detection unit that detects the amount of dust in the dust storage unit. The application control unit controls the voltage application unit to change the applied frequency while suppressing fluctuations in the current value, on the condition that it detects that the amount of dust in the dust storage unit has exceeded a predetermined dust storage threshold.

[0105] In the above configuration, when the amount of dust in the dust storage section exceeds a predetermined dust accumulation threshold, the operating sound of the motor changes. Therefore, the change in the operating sound of the motor notifies the user that a large amount of dust has accumulated in the dust storage section, and urges the user to dispose of the dust in the dust storage section.

[0106] (Technology 7) Yet another vacuum cleaner according to the above-described embodiment includes a first rotating brush and a second rotating brush that roll on the floor surface to scrape off dust on the floor surface, the drive device described in Technology 2, a dust storage unit that stores the dust scraped off by the first rotating brush and the second rotating brush, and a dust storage detection unit that detects the amount of dust in the dust storage unit. The application control unit, on the condition that it detects that the amount of dust in the dust storage unit has exceeded a predetermined dust storage threshold, controls the first voltage application unit and the second voltage application unit so as to suppress fluctuations in the current values ​​to the first motor and the second motor and to generate a discordant sound by the operating sounds of the first motor and the second motor.

[0107] In the above configuration, when the amount of dust in the dust storage section exceeds a predetermined dust threshold, a discordant sound is generated by the operating sounds of the first motor and the second motor. If the user finds this discordant sound unpleasant, the user may stop cleaning. In other words, the user can be prompted to stop cleaning when the dust storage section is full of dust.

[0108] (Technology 8) Yet another vacuum cleaner according to the above-described embodiment includes a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade configured to generate a suction force for sucking in dust while rotating, a drive device as described in Technology 1, and a dust detection unit that detects the amount of dust being scraped off by the rotating brush or the amount of dust being sucked in by the suction force generated by the rotation of the rotating blade. The application control unit controls the voltage application unit to change the application frequency while suppressing fluctuations in the current value, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

[0109] In the above configuration, when the amount of dust detected by the dust detector exceeds a predetermined dust threshold, the operating sound of the motor changes. This change in the operating sound of the motor can notify the user that there is a lot of dust in the area they are cleaning, and can encourage the user to continue cleaning in that area.

[0110] (Technology 9) A further vacuum cleaner according to the above-described embodiment includes a first rotating brush and a second rotating brush that roll over the floor surface to scrape off dust on the floor surface, a drive device as described in Technical Field 2, a dust storage unit that stores the dust scraped off by the first rotating brush and the second rotating brush, and a dust detection unit that detects the amount of dust scraped off by the first rotating brush and the second rotating brush. The application control unit controls the first voltage application unit and the second voltage application unit so as to suppress fluctuations in the current values ​​to the first motor and the second motor and to produce a consonant sound from the operating sounds of the first motor and the second motor, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

[0111] In the above configuration, when the amount of dust detected by the dust detector exceeds a predetermined dust threshold, the operating sounds of the first motor and the second motor produce a consonant sound, which makes the user feel comfortable during the cleaning operation and encourages them to continue cleaning.

[0112] (Technology 10) A further vacuum cleaner according to the above-described embodiment includes a rotating brush that rolls on a floor surface to scrape off dust or a rotating blade configured to generate a suction force for sucking in dust while rotating, the drive device described in Technical Field 1, and a motor housing that houses a motor. The motor is connected to the motor housing so that vibration of the rotor is transmitted to the motor housing. The application control unit controls the voltage application unit so that the application frequency approaches the resonant frequency of the motor housing while suppressing fluctuations in the current value, provided that a change condition is satisfied.

[0113] In the above-described configuration, the vibration of the rotor is transmitted to the motor housing, causing the motor housing to vibrate at the rotor's vibration frequency. When a predetermined change condition is met, the rotor and motor housing vibrate at a frequency close to the resonant frequency of the motor housing, increasing the vibration amplitude of the motor housing. As a result, the operating noise caused by the vibration of the motor housing increases, and this increase in operating noise can notify the user that the change condition has been met. [Industrial Applicability]

[0114] The techniques of the above-described embodiments are suitably used in devices used for cleaning work. [Explanation of symbols]

[0115] 100··········vacuum cleaner 101 Drive unit 117 Storage battery 125 Rotor 133 Rotating brush 135 First rotating brush 136 Second rotating brush 137 First motor 138 Second motor 139 Motor housing 142 Motor 143 Rotating blades 168 Voltage application section 169... Application control unit 171 Power detection unit 172 Motor housing 173 Dust accumulation detection unit 181 Dust detection unit 213 First voltage application unit 214... Second voltage application unit

Claims

1. A driving device for driving a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade that is configured to generate a suction force for sucking in dust while rotating, a motor having a rotor that rotates and drives the rotary brush or the rotary blade; a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in a magnetic field within the motor at a frequency corresponding to a frequency at which the voltage is applied to the motor; the motor is configured such that the rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the motor in response to intermittent application of a voltage to the motor, and the rotor vibrates in response to periodic changes in a magnetic field at a frequency that corresponds to the applied frequency, thereby generating an operating sound; The drive device further includes an application control unit that controls the voltage application unit so that the applied frequency is changed while suppressing fluctuations in the current value, on the condition that a predetermined change condition is satisfied.

2. A drive device that drives a first rotating brush and a second rotating brush that roll on a floor surface to scrape off dust on the floor surface, a first motor having a first rotor that rotates and drives the first rotary brush; a second motor having a second rotor that rotationally drives the second rotating brush; a first voltage application unit that applies a voltage of a predetermined magnitude to the first motor intermittently, thereby generating a periodic change in a magnetic field within the first motor at a frequency corresponding to a frequency at which the voltage is applied to the first motor; a second voltage application unit that applies a voltage of a predetermined magnitude to the second motor intermittently, thereby generating a periodic change in a magnetic field in the second motor at a frequency corresponding to a frequency at which the voltage is applied to the second motor; the first motor is configured such that the first rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the first motor in response to intermittent application of a voltage to the first motor, and the first rotor vibrates in response to a periodic change in a magnetic field at a frequency that corresponds to the applied frequency to the first motor, thereby generating an operating sound; the second motor is configured such that the second rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the second motor in response to intermittent application of a voltage to the second motor, and the second rotor vibrates in response to a periodic change in a magnetic field at a frequency that corresponds to the applied frequency to the second motor, thereby generating an operating sound; the drive device further includes an application control unit that controls the first voltage application unit and the second voltage application unit; The application control unit controls the first voltage application unit to change the application frequency to the first motor while suppressing fluctuations in the current value to the first motor, on the condition that a predetermined change condition is satisfied, and controls the second voltage application unit to change the application frequency to the second motor while suppressing fluctuations in the current value to the second motor, so that the application frequency to the second motor differs from the application frequency of the voltage to the first motor, thereby generating a discordant or consonant sound by the operating sounds of the first motor and the second motor.

3. A driving device for driving a rotating brush that rolls on a floor surface to scrape off dust on the floor surface or a rotating blade that is configured to generate a suction force for sucking in dust while rotating, a motor having a rotor that rotates and drives the rotary brush or the rotary blade; a voltage application unit that applies a voltage of a predetermined magnitude to the motor intermittently, thereby causing a periodic change in a magnetic field within the motor at a frequency corresponding to a frequency at which the voltage is applied to the motor; the motor is configured such that the rotor rotates at a rotation speed corresponding to a current value that is a time average value of a direct current flowing through the motor in response to intermittent application of a voltage to the motor, and the rotor vibrates in response to periodic changes in a magnetic field at a frequency that corresponds to the applied frequency, thereby generating an operating sound; The drive device further includes an application control unit that controls the voltage application unit so that the applied frequency increases or decreases in accordance with the pitch of the notes represented by a specified musical score while suppressing fluctuations in the current value.

4. a rotating brush that rolls on the floor surface to scrape off dust on the floor surface, or a rotating blade that is configured to generate a suction force to suck in dust while rotating; The drive device according to claim 1 ; a storage battery that stores power for the motor; a power detection unit that detects the remaining amount of power stored in the storage battery, The application control unit controls the voltage application unit to change the application frequency while suppressing fluctuations in the current value, on condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold.

5. a first rotating brush and a second rotating brush that roll on the floor surface to scrape off dust on the floor surface; The drive device according to claim 2; a storage battery that stores power for the first motor and the second motor; a power detection unit that detects the remaining amount of power stored in the storage battery, The application control unit controls the first voltage application unit and the second voltage application unit to suppress fluctuations in the current values ​​for the first motor and the second motor while causing a discordant sound to be produced by the operating sounds of the first motor and the second motor, on condition that the power detection unit detects that the remaining amount of power stored in the storage battery has fallen below a predetermined power threshold.

6. a rotating brush that rolls on the floor surface to scrape off dust on the floor surface, or a rotating blade that is configured to generate a suction force to suck in dust while rotating; The drive device according to claim 1 ; a dust storage section that stores dust scraped off by the rotating brush or dust sucked by a suction force generated by the rotation of the rotating blades; a dust storage detection unit that detects the amount of dust in the dust storage unit, The application control unit controls the voltage application unit so that the application frequency changes while suppressing fluctuations in the current value when it detects that the amount of dust in the dust storage unit has exceeded a predetermined dust storage threshold.

7. a first rotating brush and a second rotating brush that roll on the floor surface to scrape off dust on the floor surface; The drive device according to claim 2; a dust storage section that stores the dust scraped off by the first rotating brush and the second rotating brush; a dust storage detection unit that detects the amount of dust in the dust storage unit, When the application control unit detects that the amount of dust in the dust storage unit has exceeded a predetermined dust storage threshold, the application control unit controls the first voltage application unit and the second voltage application unit to suppress fluctuations in the current value for the first motor and the second motor while causing a discordant sound to be produced by the operating sounds of the first motor and the second motor.

8. a rotating brush that rolls on the floor surface to scrape off dust on the floor surface, or a rotating blade that is configured to generate a suction force to suck in dust while rotating; The drive device according to claim 1 ; a dust detection unit that detects the amount of dust scraped off by the rotating brush or the amount of dust sucked in by the suction force generated by the rotation of the rotating blades, The application control unit controls the voltage application unit so that the application frequency is changed while suppressing fluctuations in the current value, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

9. a first rotating brush and a second rotating brush that roll on the floor surface to scrape off dust on the floor surface; The drive device according to claim 2; a dust storage section that stores the dust scraped off by the first rotating brush and the second rotating brush; a dust detection unit that detects the amount of dust scraped off by the first rotating brush and the second rotating brush, The application control unit controls the first voltage application unit and the second voltage application unit to suppress fluctuations in the current value for the first motor and the second motor, while causing the operating sounds of the first motor and the second motor to produce a consonant sound, on the condition that the amount of dust detected by the dust detection unit exceeds a predetermined dust threshold.

10. a rotating brush that rolls on the floor surface to scrape off dust on the floor surface, or a rotating blade that is configured to generate a suction force to suck in dust while rotating; The drive device according to claim 1 ; a motor housing portion that houses the motor, the motor is connected to the motor accommodating portion so that vibration of the rotor is transmitted to the motor accommodating portion, The application control unit controls the voltage application unit so that the applied frequency approaches the resonance frequency of the motor accommodating unit while suppressing fluctuations in the current value, on the condition that the change condition is satisfied.

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