vacuum cleaner

Abstract

This invention provides a vacuum cleaner that suppresses the rapid deterioration of secondary batteries due to localized over-discharge by operating at high current when the battery level is low. [Solution] The electric vacuum cleaner 1 of the present invention comprises an electric blower 14 that generates suction force, a secondary battery 16 that supplies power to the electric blower 14, a control device 100 that controls the electric blower 14 and the secondary battery 16, and an operation switch 17 that turns the electric blower 14 on and off and selects the suction force. The control device 100 can set a standard operating mode and a high-speed operating mode in which the rotational speed of the electric blower 14 is higher than that of the standard operating mode. When the charge level of the secondary battery 16 is below a predetermined value, operation in the high-speed operating mode is prohibited. When high-speed operation or standard operation is selected from the operation switch 17, the electric blower 14 is operated in the standard operating mode.

Description

Technical Field

[0005] , ,

[0001] The present invention relates to an electric vacuum cleaner.

Background Art

[0002] In an electric vacuum cleaner equipped with a secondary battery, there is a device that controls the suction force of an electric blower during the next operation after charging according to the remaining amount of the secondary battery during operation. For example, in Patent Document 1, in order to keep the operation time of the electric vacuum cleaner constant, a remaining amount detection means for detecting the remaining amount of the secondary battery is provided, and according to the remaining amount of the secondary battery detected by the remaining amount detection means, a parameter for controlling the suction force of the electric blower during the next operation after charging is set.

[0003] When cleaning is finished in a state where the remaining amount of the secondary battery detected by the remaining amount detection means is below a predetermined value, the parameter is set so as to decrease the suction force of the electric blower during the next cleaning. Also, when cleaning is finished in a state where the remaining amount of the secondary battery detected by the remaining amount detection means is not below the predetermined value, the parameter is set so as to increase the suction force of the electric blower during the next cleaning within a range not exceeding a predetermined upper limit value. In Patent Document 1, parameters corresponding to the remaining amount of the secondary battery are set, and the suction force of the electric blower is automatically adjusted so that the cleaning possible time is constant.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In vacuum cleaners using secondary batteries, it has been found that when the battery level is low, supplying a large current to the electric blower, such as during high-power operation, causes a reaction distribution in the electrode plane within the battery's electrodes. This results in an overload state in only a portion of the area near the tab, leading to over-discharge in this area. In this area, a reaction occurs in which the copper current collector foil dissolves and precipitates at the negative electrode. Operating with a high current when the battery voltage is low, i.e., when the battery level is low, causes a localized over-discharge state, significantly shortening the battery's lifespan. However, if the lower limit voltage of the battery is set too high to prevent over-discharge, the operating time of the vacuum cleaner becomes short. For this reason, as described in Patent Document 1, control is implemented to accurately monitor the battery voltage and automatically adjust the cleaning time and the suction power of the electric blower.

[0006] However, Patent Document 1 only adjusts the optimal suction force parameters of the electric blower to maintain operating time, and does not restrict high-current operation when the battery capacity is low, as mentioned above. Therefore, there was a possibility that a significant reduction in battery life could occur due to localized over-discharge conditions.

[0007] The objective of the present invention is to provide a vacuum cleaner with an extended secondary battery life by suppressing the degradation of the secondary battery due to localized over-discharge. [Means for solving the problem]

[0008] To achieve the above objective, the present invention provides an electric vacuum cleaner comprising: an electric blower that generates suction force; a secondary battery that supplies power to the electric blower; a control device that controls the electric blower and the secondary battery; and an operation switch that turns the electric blower on and off and selects the suction force, wherein the control device can set a standard operating mode and a high-speed operating mode in which the rotation speed of the electric blower is higher than that of the standard operating mode, and when the charge level of the secondary battery is below a predetermined value, it prohibits operation in the high-speed operating mode, and when high-speed operation or standard operation is selected from the operation switch, it operates the electric blower in the standard operating mode. [Effects of the Invention]

[0009] According to the present invention, by suppressing the degradation of the secondary battery due to localized over-discharge, it is possible to provide a vacuum cleaner with a long secondary battery life. [Brief explanation of the drawing]

[0010] [Figure 1] This is an external perspective view of an electric vacuum cleaner stored in a stand according to an embodiment of the present invention. [Figure 2] This is an external perspective view of a vacuum cleaner used as a stick-type vacuum according to an embodiment of the present invention. [Figure 3] This is a control block diagram of an electric vacuum cleaner according to an embodiment of the present invention. [Figure 4] This is a flowchart of a control device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0011] The embodiments of the present invention will be described below with reference to the drawings. In principle, the same reference numerals are used for the same elements in all the drawings. Furthermore, descriptions of parts having the same function will be omitted. It should be noted that the configurations described below are merely embodiments, and it is not intended that the embodiments of the present invention are limited to the following specific embodiments.

[0012] Figure 1 is an external perspective view of an electric vacuum cleaner stored in a stand according to an embodiment of the present invention. Figure 2 is an external perspective view of an electric vacuum cleaner used as a stick-type device according to an embodiment of the present invention.

[0013] In this embodiment 1, the directions are indicated by arrows, defining front / back, left / right, and up / down from the user's perspective while cleaning.

[0014] As shown in Figures 1 and 2, the electric vacuum cleaner 1 comprises a vacuum cleaner body 10 that forms the outer casing, an extension tube 20 with one end connected to the vacuum cleaner body 10, and a suction nozzle 30 connected to the other end of the extension tube 20. In addition, the electric vacuum cleaner 1 of this embodiment is equipped with a brush part 40 at the tip of the vacuum cleaner body 10, and when the extension tube 20 is removed from the vacuum cleaner body 10, it can be used as a handheld electric vacuum cleaner.

[0015] The front of the vacuum cleaner body 10 is a dust collection chamber 12 covered by an openable and closable dust collection lid 11. Behind the dust collection chamber 12 is an electric blower 14 that generates suction power, and behind the electric blower 14 is a secondary battery 16, which is a pack of multiple battery cells 160. The secondary battery 16 supplies power to the electric blower 14.

[0016] The upper rear of the vacuum cleaner body 10 is equipped with a handle 13 for the user to grip while cleaning. The handle 13 has an operation switch 17 for turning the electric blower 14 on and off and selecting the suction power. The operation switch 17 has a standard operating mode and a high-power operating mode in which the rotation speed of the electric blower 14 is higher and the suction power is stronger than in the standard operating mode.

[0017] When the operation switch on the control switch 17 is operated, the electric blower 14 is activated and suction force is generated, dust is sucked in from the suction port 30, passes through the extension pipe 20, and is collected in the dust collection chamber 12.

[0018] When not in use, the vacuum cleaner 1 is placed on the stand 50 to charge the secondary battery 16.

[0019] Figure 3 is a control block diagram of an electric vacuum cleaner according to an embodiment of the present invention. The vacuum cleaner body 10 is equipped with an electric blower 14, a secondary battery 16, and a control device 100 that controls the electric vacuum cleaner 1.

[0020] The control device 100 includes a voltage detection unit 110 that detects the voltage of the secondary battery 16, a determination unit 120 that calculates the remaining amount of the secondary battery 16 from the voltage of the secondary battery 16 detected by the voltage detection unit 110 and determines whether the electric blower 14 can operate according to the calculation result and an operation command from the operation switch 17, a storage unit 130 that stores the voltage value detected by the voltage detection unit 110 via the determination unit 120, and a control unit 140 that controls the electric blower 14 based on the determination result of the determination unit 120. The voltage detection unit 110 preferably detects the voltage of each of the plurality of battery cells 160 constituting the secondary battery 16 and performs control using the voltage value of the battery cell 160 with the lowest voltage among the plurality of battery cells 160. By doing so, over-discharge of the battery cell 160 with the lowest voltage can be suppressed.

[0021] In addition, the electric vacuum cleaner 1 is provided with a display unit 18 for displaying information. The display unit 18 is provided, for example, on the handle unit 13. The control device 100 can set a standard operation mode and a strong operation mode in which the rotation speed of the electric blower 14 is higher and the suction force is stronger than the standard operation mode.

[0022] As for how to use the electric vacuum cleaner, it is not always necessary to use up the battery until the remaining battery level reaches zero. When the remaining battery level is low and an operation of supplying a large current such as strong operation to the electric blower is performed, a reaction distribution occurs in the in-plane direction of the electrode surface at the electrode inside the battery, and only a part of the region near the tab becomes an overloaded state, over-discharge occurs in this region, and a reaction in which copper, which is the current collector foil, dissolves and precipitates occurs at the negative electrode in this region. Means for suppressing these will be described below.

[0023] Figure 4 is a flowchart of a control device according to an embodiment of the present invention. The operation switch 17 of this embodiment is equipped with a stop switch, a standard operation switch, and a high-speed operation switch. When any of these switches is pressed, the electric blower 14 operates in either the standard operation mode or the high-speed operation mode. When the stop button is pressed, the operation of the electric blower 14 stops. The voltage detection unit 110 of this embodiment detects the closed-circuit voltage (CCV) of each of the multiple battery cells 160 and the total closed-circuit voltage (CCV) of the multiple battery cells 160. Normally, the total closed-circuit voltage (CCV) of the multiple battery cells 160 is used. Although not shown in the figure, if the variation in the closed-circuit voltages (CCV) of the multiple battery cells 160 exceeds a predetermined value, the operation stops and the details of the abnormality are displayed.

[0024] The vacuum cleaner 1 is in operation. The determination unit 120 determines whether or not the stop switch on the operation switch 17 has been pressed (step S401).

[0025] If the stop switch on the operation switch 17 is pressed (Yes in step S401), the determination unit 120 detects that the switch has been pressed, and the control unit 140 obtains the detection result from the determination unit 120 and stops the electric blower 14 (step S402).

[0026] Furthermore, after the electric blower 14 stops, the determination unit 120 operates the voltage detection unit 110 to measure the voltage E of the secondary battery 16 and stores it in the storage unit 130 (step S403). The determination unit 120 then determines whether the State of Charge (SOC) of the secondary battery 16 is 20% or less (step S404).

[0027] The memory unit 130 stores in advance the relationship between the remaining battery capacity Ah and voltage of the rechargeable battery 16 when it is new. The voltage of the rechargeable battery 16 decreases as it discharges. The determination unit 120 calculates the remaining capacity of the rechargeable battery 16 by comparing the relationship between the remaining battery capacity Ah and voltage of the rechargeable battery 16 when it is new, which has been stored in advance, with the voltage of the detected rechargeable battery 16. The determination unit 120 then calculates the state of charge (SOC) (%) using the following formula (a).

[0028] State of Charge (SOC) (%) = (Remaining battery capacity Ah / Fully charged battery capacity Ah) × 100 …(a) Although the explanation will be omitted, the control device 100 may also change the full charge capacity Ah of the secondary battery 16 according to the degradation rate SOH (%) of the secondary battery 16. Furthermore, if the full charge capacity Ah of the secondary battery 16 is changed, the relationship between the battery capacity and voltage of the secondary battery 16 may also be changed.

[0029] If the State of Charge (SOC) is below a predetermined value (20% or less in this embodiment) (Yes in step S404), the determination unit 120 determines that operation in high-power mode is not permitted and outputs a command to the control unit 140 to prohibit high-power operation (step S405).

[0030] The determination unit 120 operates the voltage detection unit 110 to measure the voltage E of the secondary battery 16 and determines whether or not a charging operation has been performed (step S406).

[0031] If a charging operation is performed (Yes in step S406), the determination unit 120 repeats the process from step S404.

[0032] If no charging operation is performed (No. in step S406), the determination unit 120 determines whether the voltage E of the secondary battery 16 is below a predetermined voltage threshold (voltage E1) (step S407). Voltage E1 is set to the voltage at which the secondary battery is indicated as having no remaining charge. Since the deterioration of the secondary battery 16 accelerates when its voltage falls below a predetermined voltage, voltage E1 is set to a value that can suppress the accelerated deterioration of the secondary battery 16.

[0033] If the voltage E of the secondary battery 16 is higher than a predetermined voltage threshold (voltage E1) (No. in step S407), the determination unit 120 determines whether the standard operation switch or the high-power operation switch has been pressed from the operation switch 17 (step S408).

[0034] When the determination unit 120 detects that the standard operation switch or the high-power operation switch has been pressed from the operation switch 17 (Yes in step S408), the control unit 140 obtains the detection result from the determination unit 120 and operates the electric blower 14 in standard operation mode (step S409). Since a command to prohibit high-power operation was issued in step S405, the control unit 140 operates the electric blower 14 in standard operation mode even if the high-power operation switch is pressed from the operation switch 17. After the vacuum cleaner 1 starts operating in standard operation mode, the control device 100 repeats the process from step S401. If the electric blower 14 starts operating in standard operation mode despite the user pressing the high-power operation switch, the user can notice from the display that the battery level is low.

[0035] If the determination unit 120 does not detect that the standard operation switch or the high-power operation switch has been pressed (No. in step S408), it repeats the process in step S408.

[0036] In step S404, if the charge level (SOC) is greater than 20% (No. in step S404), the determination unit 120 determines whether the standard operation switch or the high-power operation switch has been pressed from the operation switch 17 (step S410).

[0037] When the determination unit 120 detects that the high-power operation switch or the standard operation switch has been pressed from the operation switch 17 (Yes in step S410), the control unit 140 obtains the detection result from the determination unit 120 and operates the electric blower 14 in high-power operation mode or standard operation mode (step S411). After starting operation of the vacuum cleaner 1 in high-power operation mode or standard operation mode, the control device 100 repeats the process from step S401. Since no command to prohibit high-power operation has been issued, the control unit 140 operates the electric blower 14 in high-power operation mode or standard operation mode according to the operation mode via the operation switch 17.

[0038] In step S401, if the stop switch of the operation switch 17 is not pressed (No. of step S401), the determination unit 120 determines whether the voltage E of the secondary battery 16 is less than or equal to a predetermined voltage threshold (voltage E1) (step S412).

[0039] If the voltage E of the secondary battery 16 is higher than a predetermined voltage threshold (voltage E1) (No. in step S412), the control device 100 repeats the process from step S401.

[0040] If the voltage E of the secondary battery 16 is below a predetermined voltage threshold (voltage E1) (Yes in step S412), the determination unit 120 transmits the determination result to the control unit 140, and the control unit 140 stops the operation of the electric blower 14 based on the determination result of the determination unit 120 (step S413). The control unit 140 also displays on the display unit 18 that there is no battery charge remaining (step S414).

[0041] When charging of the secondary battery 16 begins (step S415), the determination unit 120 executes the process in step S404.

[0042] In step S406, if a charging operation is performed (Yes in step S406), the determination unit 120 executes the process in step S404.

[0043] Furthermore, in step S407, if the voltage E of the secondary battery 16 is below a predetermined voltage threshold (voltage E1) (Yes in step S407), the control unit 140 displays on the display unit 18 that there is no remaining battery charge (step S414).

[0044] According to this embodiment, the operation of the electric blower 14 is stopped when the voltage E of the secondary battery 16 is below a predetermined voltage threshold (voltage E1), thereby suppressing deterioration of the secondary battery due to over-discharge.

[0045] Furthermore, according to this embodiment, when the charge level (SOC) is below a predetermined value, high-power operation is prohibited, and even if the high-power operation switch is pressed from the operation switch 17, the electric blower 14 operates in standard operation mode, thereby suppressing localized over-discharge at the electrodes.

[0046] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail for the purpose of explaining the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0047] 1...Vacuum cleaner, 10...Vacuum cleaner body, 11...Dust collection cover, 12...Dust collection chamber, 13...Handle, 14...Electric blower, 16...Rechargeable battery, 17...Operation switch, 18...Display unit, 20...Extension tube, 30...Suction nozzle, 40...Brush unit, 50...Stand, 100...Control device, 110...Voltage detection unit, 120...Determination unit, 130...Storage unit, 140...Control unit, 160...Battery cell

Claims

1. In an electric vacuum cleaner comprising an electric blower that generates suction force, a secondary battery that supplies power to the electric blower, a control device that controls the electric blower and the secondary battery, and an operation switch that turns the electric blower on and off and selects the suction force, The control device is capable of setting a standard operating mode and a high-speed operating mode in which the rotation speed of the electric blower is higher than that of the standard operating mode, and when the charge level of the secondary battery is below a predetermined value, it prohibits operation in the high-speed operating mode, and when high-speed operation or standard operation is selected from the operation switch, it operates the electric blower in the standard operating mode.

2. In the vacuum cleaner according to claim 1, The control device comprises a voltage detection unit for detecting the voltage of the secondary battery, and the vacuum cleaner is characterized in that it calculates the charge level of the secondary battery according to the voltage detected by the voltage detection unit.

3. In the vacuum cleaner according to claim 2, The control device is characterized by changing the full charge capacity of the secondary battery according to the degradation rate of the secondary battery.

4. In the vacuum cleaner according to any one of claims 1 to 3, The control device is characterized in that it stops the operation of the electric blower when the detected voltage of the secondary battery falls below a predetermined threshold.

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