Vacuum cleaner

Abstract

To improve operability of a vacuum cleaner by grasping an operation mode and an operation executable time according to the deterioration of a secondary battery.SOLUTION: A vacuum cleaner 1 includes an electric blower 14 for generating suction force, a secondary battery 160 for supplying power to the electric blower 14, and a control device 100 for controlling the electric blower 14 and the secondary battery 160. 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 than that of the standard operation mode. When the strong operation mode is set, a time when a battery voltage of the secondary battery 160 reaches a lower limit set voltage or a time when a battery temperature of the secondary battery 160 reaches an upper limit set temperature, whichever is shorter, is made to be an operation executable time of the electric blower 14, and the operation executable time is displayed in a display unit 18.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a vacuum cleaner. [Background technology]

[0002] In a rechargeable vacuum cleaner that is powered by a secondary battery, operation may stop if the voltage of the secondary battery drops suddenly.

[0003] One technique to solve this problem is described in Patent Document 1. In Patent Document 1, when judging the remaining charge of the secondary battery, different judgment voltages and different judgment times are set according to the operating state of the electric blower, and the operation of the electric blower and the remaining charge of the previous battery are notified. In Patent Document 1, multiple judgment criteria for the battery voltage are provided, and the judgment time is changed for each operating state of the electric blower and each judgment criterion, preventing the vacuum cleaner from suddenly stopping during cleaning while suppressing deterioration of accuracy, and efficiently using up the limited battery capacity to the very end. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-600 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a vacuum cleaner, there is a strong operation mode that rotates the electric blower more powerfully. In the strong operation mode, a large current is discharged from the secondary battery compared to the standard mode, so the battery temperature is likely to rise. The upper limit temperature of the battery is set from the viewpoint of the life span and safety of the secondary battery. For example, when the temperature is high or when the deterioration of the secondary battery progresses and the internal resistance increases, the battery temperature is likely to rise. For this reason, even if there is a remaining battery charge, the battery protection temperature threshold may be reached and the operation of the electric blower may be stopped. In the technology described in Patent Document 1, it is not possible to grasp the available operation time according to the operation mode or the deterioration of the secondary battery, and operability is poor.

[0006] An object of the present invention is to solve the above problems and provide a vacuum cleaner that allows the remaining operating time according to the operating mode and the deterioration of the secondary battery to be known, thereby improving operability. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, 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, and a control device that controls the electric blower and the secondary battery, wherein the control device is capable of setting a standard operation mode and a strong operation mode in which the rotation speed of the electric blower is higher than that in the standard operation mode, and when the strong operation mode is set, the shorter of the time for the battery voltage of the secondary battery to reach a lower limit set voltage or the time for the battery temperature of the secondary battery to reach an upper limit set temperature is set as the operable time of the electric blower, and the operable time is displayed on a display unit. Effect of the Invention

[0008] According to the present invention, it is possible to provide a vacuum cleaner with improved operability, which allows the remaining operating time according to the operating mode and the deterioration of the secondary battery to be known. [Brief description of the drawings]

[0009] [Figure 1]1 is a perspective view of the appearance of a vacuum cleaner stored in a stand according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view of the appearance of a stick-type vacuum cleaner according to an embodiment of the present invention; [Diagram 3] FIG. 2 is a control block diagram of the electric vacuum cleaner according to the embodiment of the present invention. [Figure 4] 2 is a diagram showing a configuration of a battery model 131 in a determination unit 140 according to the embodiment of the present invention. FIG. [Diagram 5] 10 is a flowchart showing the process of a determination unit 140 according to the embodiment of the present invention. [Figure 6] FIG. 13 is a diagram showing the relationship between the operation time, the upper limit temperature setting, and the lower limit voltage setting when the capacity maintenance rate SOHQ is 100%. [Figure 7] FIG. 13 is a diagram showing the relationship between the operation time, the upper limit temperature setting, and the lower limit voltage setting when the capacity maintenance rate SOHQ is 90%. [Figure 8] FIG. 13 is a diagram showing the results of comparing the present embodiment with a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In principle, the same elements are given the same reference numerals in all drawings. Furthermore, explanations of parts having the same functions will be omitted. Note that the configurations described below are merely examples, and it is not intended that the embodiment of the present invention is limited to the specific embodiments described below.

[0011] Fig. 1 is a perspective view of the appearance of a vacuum cleaner according to an embodiment of the present invention, showing a state where the vacuum cleaner is stored in a stand, and Fig. 2 is a perspective view of the appearance of a vacuum cleaner according to an embodiment of the present invention, showing a state where the vacuum cleaner is used as a stick type vacuum cleaner.

[0012] In the first embodiment, the directions are defined as front, back, left, right, up and down from the viewpoint of the user performing cleaning, as indicated by the arrows.

[0013] 1 and 2, the vacuum cleaner 1 comprises a vacuum cleaner body 10 constituting an outer shell, an extension tube 20 having one end connected to the vacuum cleaner body 10, and a suction nozzle body 30 connected to the other end of the extension tube 20. The vacuum cleaner 1 of this embodiment is also provided with a brush part 40 at the tip of the vacuum cleaner body 10, and can be used as a handheld vacuum cleaner when the extension tube 20 is removed from the vacuum cleaner body 10.

[0014] A dust collection chamber 12 covered with an openable and closable dust collection lid 11 is provided at the front of the vacuum cleaner body 10. An electric blower 14 that generates suction force is provided at the rear of the dust collection chamber 12, and a battery pack 16 having a plurality of secondary batteries 160 is provided at the rear of the electric blower 14. The secondary batteries 160 supply power to the electric blower 14.

[0015] A handle 13 is provided at the upper rear of the vacuum cleaner body 10, which is held by the user when cleaning. An operation switch 17 is provided on the handle 13 for turning the electric blower 14 on and off and adjusting the suction power. The operation switch 17 has a standard operation mode and a strong operation mode in which the rotation speed of the electric blower 14 is faster and the suction power is stronger than in the standard operation mode.

[0016] When the operation switch of the operating switch 17 is operated, the electric blower 14 is operated and suction force is generated, dust is sucked through the suction body 30 , passes through the extension tube 20 and is collected in the dust collection chamber 12 .

[0017] When not in use, the vacuum cleaner 1 is placed on the stand 50 and the secondary battery 160 is charged.

[0018] 3 is a control block diagram of the electric vacuum cleaner according to the embodiment of the present invention. The vacuum cleaner body 10 is provided with a control device 100 that controls the electric vacuum cleaner 1, including the electric blower 14 and the secondary battery 160.

[0019] The control device 100 includes a temperature detection unit 110 for detecting the temperature of the secondary battery 160, an outside air temperature detection unit 111 for detecting the outside air temperature, a voltage detection unit 120 for detecting the voltage of the secondary battery 160, a current detection unit 130 for detecting the current of the secondary battery 160, a determination unit 140 for determining the deterioration state of the secondary battery 160 based on the temperature of the secondary battery 160 detected by the temperature detection unit 110, the outside air temperature detected by the outside air temperature detection unit 111, the voltage of the secondary battery 160 detected by the voltage detection unit 120, and the current of the secondary battery 160 detected by the current detection unit 130, and determining whether or not the electric blower 14 can be operated in accordance with the determination result and an operation command from the operation switch 17, and a control unit 150 for controlling the electric blower 14 based on the determination result of the determination unit 140. The electric vacuum cleaner 1 also includes 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 in the standard operation mode.

[0020] Next, a description will be given of the configuration of the determination unit 140. Fig. 4 is a diagram showing the configuration of the battery model 131 in the determination unit 140 according to an embodiment of the present invention.

[0021] The battery model 131 is composed of a voltage model 132, a temperature model 133, and a deterioration model .

[0022] In the determination unit 140, an arithmetic unit (not shown) calculates the initial state of charge (SOC) and initial state of health (SOH) of the secondary battery 160 based on the voltage V, current I, and surface temperature T of the secondary battery 160, and stores them in a memory unit. The initial state of charge (SOC) and initial state of health (SOH) are input to the battery model 131.

[0023] The charging rate SOC is generally calculated using the following formula (a).

[0024] SOC(%)=(battery remaining capacity Ah / battery fully charged capacity Ah)×100…(a) In addition, the deterioration rate SOH is generally calculated using the following formula (b).

[0025] Degradation rate SOH (%) = (fully charged battery capacity at degradation time Ah / fully charged battery capacity at initial time Ah) × 100…(b) The voltage model 132 outputs the voltage, charging rate SOC, transition of temperature change (amount of heat generated) of the secondary battery 160, and deterioration rate SOH of the secondary battery 160 in an arbitrary deterioration state.

[0026] The temperature model 133 inputs the heat generation amount and the outside air temperature output from the voltage model 132, and outputs the temperature transition of the battery based on these.

[0027] The deterioration model 134 successively updates the battery deterioration rate SOH based on the transition of the charging rate SOC of the secondary battery 160, the load state of the current I, and the temperature of the secondary battery 160, and outputs it to the voltage model 132. Generally, the battery deterioration rate SOH includes a capacity maintenance rate SOHQ and a resistance rise rate SOHR. In this embodiment, the capacity maintenance rate SOHQ is used to set the voltage, and the resistance rise rate SOHR is used to set the temperature.

[0028] The voltage model 132 calculates the voltage behavior of the next time step based on this updated deterioration rate SOH. By performing such a coupled simulation, the battery model finally outputs the battery voltage, charging rate SOC, temperature change transition, and deterioration rate SOH (capacity maintenance rate SOHQ, resistance rise rate SOHR). With this configuration, it is possible to simulate the current waveform of an actual DC stick vacuum cleaner and the deterioration transition and temperature transition from the outside temperature.

[0029] In this embodiment, in order to reproduce the battery voltage, the equivalent circuit model of the battery shown in Fig. 4 was used as the battery model 131. It was expressed by the Open Circuit Voltage (OCV) component indicating the electromotive force of the battery, the DC resistance component R0 expressing the ohmic resistance of the components that make up the battery, and the polarization terms Vp1 and Vp2 expressing the resistance due to ion diffusion and electronic conduction in solids. The polarization terms are expressed by the polarization resistance Rp and a capacitor with a time constant τ. The equivalent circuit model can be expressed as equations (1) and (2).

[0030]

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[0031]

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[0032] CCV is the closed circuit voltage, T is the battery temperature, t is time, and Vp_z indicates the previous polarization value. Since OCV is a value that changes depending on the charging rate SOC, SOC was used as the input. Since R0 and Rp are values ​​that change depending on the charging rate SOC and battery temperature T, the charging rate SOC and battery temperature T were used as the input.

[0033] Battery heat generation Q battery Since is determined by the battery resistance including the polarization term, it is expressed as equation (3).

[0034]

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[0035] The temperature model 133 was created based on Newton's law of cooling. The heat balance equations were the following equations (4) to (6), and the temperature rise was expressed by equation (7).

[0036]

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[0037]

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[0038]

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[0039]

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[0040] Q total is the final heat generation amount of the battery, Q radiation is the radiant heat, Q transfer is the heat loss by heat transfer, σ is the Stefan-Boltzmann constant, ε is the emissivity, S is the surface area, T battery is the battery temperature, Tm is the coolant temperature, α is the heat transfer coefficient, ΔT is the battery temperature rise, and C is the battery heat capacity. σ, ε, and C are values ​​that can be read from the specifications if the battery type and can material are known. Radiant heat from the battery cell is absorbed by the wall surface of the pack exterior. As a result, the value of radiant heat is determined by the surface area of ​​the outer wall surface of the pack exterior, and is therefore considered to be small enough to be ignored from the perspective of the battery cell. For this reason, in this embodiment, Q radiation was set to 0.

[0041] The deterioration model 134 calculates the capacity maintenance rate SOHQ and the resistance increase rate SOHR mainly based on conditions such as the battery temperature, current, charging rate SOC, operation interval, etc. The operation interval is the number of days between which the deterioration simulation is calculated.

[0042] The overall flow of the battery model 131 is as follows: the operation results for one day are calculated using the voltage model 132 and the temperature model 133, a representative value is extracted from this result and sent to the deterioration model 134, deterioration calculations for a specified number of days are performed, and the updated capacity maintenance rate SOHQ and resistance increase rate SOHR are returned to the voltage model 132. By repeating this a specified number of times, the deterioration rate up to a specified number of years can be calculated.

[0043] Capacity retention rate SOHQ is the capacity retention rate SOHQ in storage test strage and capacity retention rate SOHQ in cycle test cycle It can be expressed as the sum of a strage and a cycle are the deterioration coefficients in the storage test and cycle test, respectively, and differ depending on the battery used.

[0044] The formulas for calculating the capacity maintenance rate SOHQ and the resistance increase rate SOHR are shown in formulas (8) and (9).

[0045]

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[0046]

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[0047] To calculate the capacity retention rate SOHQ, storage tests and cycle tests were performed under various test conditions. First, the deterioration rate coefficient a strage The deterioration due to storage is subtracted from the deterioration due to the cycle test, the deterioration value of the battery capacity due to the cycle test is obtained, and the cycle deterioration coefficient a is calculated from the results of each cycle test. cycle Similarly, the resistance rise rate SOHR is calculated by measuring the change in battery resistance from storage tests and cycle tests, and b strage and b cycle This is calculated as the deterioration calculation formula.

[0048] Next, the process of the determination unit 140 will be described. FIG. 5 is a flowchart showing the process of the determination unit 140 according to the embodiment of the present invention.

[0049] In FIG. 5, when the vacuum cleaner is being charged, the determination unit 140 calculates the capacity maintenance rate SOHQ, estimates the resistance increase rate SOHR based on a calculation formula stored in advance, and stores it (step S501).

[0050] When the user operates operation switch 17 to turn on the operation switch of vacuum cleaner 1 (step S502), determination unit 140 determines whether the input operation switch is in the strong operation mode or not (step S503).

[0051] When the operation switch is in the strong operation mode (Yes in step S503), the determination unit 140 calculates the time to reach the lower limit voltage from the discharge curve and the capacity maintenance rate SOHQ stored in advance, and the time to reach the upper limit temperature from the resistance rise rate SOHR, and displays whichever is shorter on the display unit 18 (step S504). The shorter time displayed on the display unit 18 becomes the operable time of the vacuum cleaner 1 (electric blower 14). When the secondary battery 160 reaches the lower limit voltage or the upper limit temperature, the determination unit 140 transmits the information to the control unit 150, and the control unit 150 stops the operation of the vacuum cleaner 1 (electric blower 14) (step S506). The discharge curve is created by plotting multiple values ​​of the capacity maintenance rate SOHQ against the number of charge / discharge cycles, for example, and connecting these values, and is a value that can be arbitrarily set by the user or manufacturer. The discharge curve is stored in advance in the storage unit of the determination unit 140.

[0052] If the operation switch is not in the strong operation mode (No in step S503), that is, in the standard operation mode, determination unit 140 calculates the time until the lower limit voltage is reached from the discharge curve and capacity maintenance rate SOHQ stored in advance, and displays it on display unit 18 (step S505). The time displayed on display unit 18 becomes the operable time of vacuum cleaner 1 (electric blower 14).

[0053] Then, when secondary battery 160 reaches the lower limit set voltage, determination unit 140 transmits that information to control unit 150, and control unit 150 stops the operation of vacuum cleaner 1 (electric blower 14) (step S506).

[0054] After the operation of the vacuum cleaner 1 (electric blower 14) is stopped, the determination unit 140 determines whether or not the secondary battery 160 has reached the lower limit voltage setting (step S507). If the secondary battery 160 has reached the lower limit voltage setting and the operation of the vacuum cleaner 1 (electric blower 14) is stopped (Yes in step S507), the determination unit 140 causes the display unit 18 to display that the secondary battery 160 has no remaining charge (step S508).

[0055] If secondary battery 160 has not reached the lower limit voltage setting (No in step S507), judgment unit 140 judges whether secondary battery 160 has reached the upper limit temperature setting (step S509). If secondary battery 160 has reached the upper limit temperature setting and operation of vacuum cleaner 1 (electric blower 14) has stopped (Yes in step S509), judgment unit 140 causes display unit 18 to display that the temperature of secondary battery 160 is high (step S510).

[0056] If secondary battery 160 has not reached the upper limit set temperature (No in step S511), determination unit 140 stops vacuum cleaner 1 (electric blower 14) normally without displaying a warning on display unit 18 (step S511).

[0057] Fig. 6 is a diagram showing the relationship between the operation time and the upper limit set temperature and the lower limit set voltage when the capacity maintenance rate SOHQ is 100%. Fig. 7 is a diagram showing the relationship between the operation time and the upper limit set temperature and the lower limit set voltage when the capacity maintenance rate SOHQ is 90%. Figs. 6 and 7 show the state during operation in the strong operation mode.

[0058] 6 and 7, the vertical axis indicates the temperature and voltage of secondary battery 160, and the horizontal axis indicates the operation time of vacuum cleaner 1 (electric blower 14).

[0059] In the determination unit 140, an upper limit temperature and a lower limit voltage are set in order to protect the secondary battery 160. In this embodiment, the upper limit temperature is set based on the capacity maintenance rate SOHQ, and the lower limit voltage is set based on the resistance rise rate SOHR.

[0060] When power is supplied from secondary battery 160 and vacuum cleaner 1 (electric blower 14) starts operating, battery temperature (1) of secondary battery 160 rises and battery voltage (1) of secondary battery 160 drops. Then, in the example shown in Fig. 6 where capacity maintenance rate SOHQ is 100%, battery voltage (1) of secondary battery 160 reaches a lower limit set voltage earlier than the time for battery temperature (1) to reach an upper limit set temperature, so the time for battery voltage (1) of secondary battery 160 to reach the lower limit set voltage is estimated and the available operation time of vacuum cleaner 1 (electric blower 14) is displayed on display unit 18.

[0061] In the example shown in FIG. 7 where the capacity maintenance rate SOHQ is 90%, the battery temperature (2) of the secondary battery 160 reaches the upper limit set temperature earlier than the time when the battery voltage (2) reaches the lower limit set voltage, so the time when the battery temperature (2) of the secondary battery 160 reaches the upper limit set temperature is estimated, and the operable time of the vacuum cleaner 1 (electric blower 14) is displayed on the display unit 18.

[0062] The effects of this embodiment will be described. Fig. 8 is a diagram showing the results of comparing this embodiment with a comparative example. In this embodiment, remaining operation time estimation is performed based on the battery voltage and the battery temperature.

[0063] When the capacity maintenance rate SOHQ is 100%, the error in the remaining operation time is 3% in this embodiment (1). Also, in the comparative example (1), the error in the remaining operation time is 3%, similar to this embodiment (1).

[0064] Next, when the capacity maintenance rate SOHQ is 90%, in this embodiment (2), it is estimated that the battery temperature (2) will reach the upper limit set temperature before the battery voltage (2) reaches the lower limit set voltage, so the error in the remaining operation time is 3%.

[0065] When the capacity maintenance rate SOHQ is 90%, in comparative example (2), only the time to reach the lower limit voltage is estimated, resulting in an error of 15% in the remaining operation time. That is, in comparative example (2), the battery temperature (2) reaches the upper limit temperature in a time shorter than the estimated operable time, resulting in an error of 15% in the remaining operation time. As the deterioration of a secondary battery progresses, the internal resistance increases, making it easier for the temperature of the secondary battery to rise.

[0066] In the present embodiment (2), it is estimated that the battery temperature (2) will reach the upper limit set temperature before the battery voltage (2) reaches the lower limit set voltage, and this time is displayed as the remaining operating time. Therefore, even when the secondary battery is in an advanced deteriorated state and electric blower 14 is operated in the strong operating mode, the remaining operating time can be determined with little error, thereby improving the operability of the vacuum cleaner.

[0067] The present invention is not limited to the above-mentioned embodiment, and various modifications are included. For example, the above-mentioned embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to those including all of the configurations described. Also, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Also, it is possible to add, delete, or replace a part of the configuration of each embodiment with another configuration. [Explanation of symbols]

[0068] 1...electric vacuum cleaner, 10...vacuum cleaner body, 11...dust collection lid, 12...dust collection chamber, 13...handle section, 14...electric blower, 16...battery pack, 17...operation switch, 18...display section, 20...extension tube, 30...suction nozzle body, 40...brush section, 50...stand, 100...control device, 110...temperature detection section, 111...outdoor air temperature detection section, 120...voltage detection section, 130...current detection section, 131...battery model, 132...voltage model, 133...temperature model, 134...deterioration model, 140...determination section, 150...control section, 160...secondary battery

Claims

1. An electric vacuum cleaner including an electric blower that generates suction force, a secondary battery that supplies power to the electric blower, and a control device that controls the electric blower and the secondary battery, The control device can set a standard operation mode and a strong operation mode in which a rotation speed of the electric blower is made higher than that in the standard operation mode, When the strong operation mode is set, the available operation time of the electric blower is determined to be the shorter of the time for the battery voltage of the secondary battery to reach a lower limit set voltage or the time for the battery temperature of the secondary battery to reach an upper limit set temperature, and the available operation time is displayed on a display unit.

2. 2. The vacuum cleaner according to claim 1, When the standard operation mode is set, the control device determines the time when the battery voltage of the secondary battery reaches a lower limit set voltage as the operable time of the electric blower, and displays the operable time on the display unit.

3. 3. The vacuum cleaner according to claim 1, The control device calculates a time for the battery voltage of the secondary battery to reach a lower limit voltage based on a capacity maintenance rate SOHQ of the secondary battery.

4. 4. The vacuum cleaner according to claim 3, The control device calculates the time required for the battery temperature of the secondary battery to reach an upper limit set temperature based on a resistance rise rate SOHR of the secondary battery.

5. 5. The vacuum cleaner according to claim 4, The vacuum cleaner is characterized in that the display unit is provided on a handle unit that is held by a user when cleaning.

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