Cleaning device and method for operating a cleaning device

Description

[0001] The invention relates to a cleaning device and a method for operating a cleaning device. In particular, the invention relates to a cleaning device with a drive unit for driving a blower and / or a cleaning actuator and an accumulator that supplies the drive unit with energy during operation, wherein the drive unit can be operated at several power levels, which are stored in a control and / or regulating device of the cleaning device. Furthermore, the invention relates in particular to a method for operating such a cleaning device.

[0002] For cleaning devices powered by a rechargeable battery, it is currently common practice to switch them off at a predefined low-voltage threshold. This ensures that sufficient energy remains in the battery to indicate its discharge status. However, the battery is not discharged too deeply to prevent damage. Furthermore, it is impractical for the cleaning device to switch off completely, including any indicators it may have, thus preventing the user from receiving any feedback, such as information about the battery's charge level.

[0003] The discharge time from a fully charged battery to the undervoltage threshold determines the operating time of the cleaning device and depends, among other things, on the selected power level. This means that the available energy in the battery is not used to its maximum potential. To enable longer operating times for a user of the cleaning device, more expensive battery cells with higher capacity may be used.

[0004] US patent 2015 / 145444 A1 discloses a cleaning device with a drive unit configured to drive a blower and a cleaning actuator, an accumulator configured to supply energy to the drive unit, and a control and regulating device in which several power levels for the operation of the drive unit are stored.

[0005] The invention thus addresses the problem of providing a cleaning device with a drive unit and a battery, and a method for operating a cleaning device, that makes optimal use of the available battery cell capacity. The use of more expensive battery cells with higher capacity should be avoided.

[0006] According to the invention, this problem is solved by a cleaning device with the features of claim 1 and a method with the features of claim 5. Advantageous embodiments and further developments of the invention are described in the following dependent claims.

[0007] The invention is based on the fundamental principle that, due to the physical behavior of the battery, a constant power draw results in an increased current flow while a decreased voltage level. Due to the battery's internal resistance, at higher power draws, the voltage level at the battery terminals drops to such an extent that a discharge cut-off voltage is reached, and the battery is considered "empty." This means that at higher power draws, only a smaller portion of the battery's capacity can be used. At lower loads, the discharge cut-off voltage is reached later, allowing for more efficient use of the battery's capacity. Therefore, each power level is assigned an individual, predetermined cut-off threshold, resulting in different cut-off thresholds for each power level.

[0008] The advantages achievable with the invention, besides enabling a longer operating time of the cleaning device at lower power levels, are that the user can clean a larger area without using more expensive accumulator cells with higher cell capacity.

[0009] The invention relates to a cleaning device with a drive unit designed to drive a blower and / or a cleaning actuator, an accumulator designed to supply energy to the drive unit, and a control and / or regulating device in which several power levels are stored, with which the drive unit is operated with an individual load assigned to the respective power level, wherein each power level is assigned an individual, predetermined cut-off threshold which depends on the load of the respective power level.

[0010] When the cleaning device is operating at a current power level, and the battery's pack voltage or cell voltage equals the individual, predetermined cutoff threshold assigned to that current power level, the current power level is switched off. The individual, predetermined cutoff threshold is the threshold at which the power level to which it is assigned is switched off. The higher the power level, the higher the assigned individual, predetermined cutoff threshold.

[0011] In a preferred embodiment, the control device is configured and designed to switch from a current power level to a lower power level during operation by switching off the cleaning device when the individual, predetermined switch-off threshold associated with the current power level is reached and then restarting the cleaning device. This ensures that after the cleaning device restarts, a user can only select a lower power level than the one that was active before the restart. This allows the cleaning device to continue operating at the lower power level if the user so desires.

[0012] Preferably, each power level is assigned an individual, predetermined switch-on threshold, which is stored in the control and / or regulating device. The higher the power level, the higher the assigned individual, predetermined switch-on threshold.

[0013] Alternatively, the control and / or regulating device is preferably configured and designed to automatically switch from a current power level to a lower power level during operation when the individual, predetermined shutdown threshold assigned to the current power level is reached. This allows the cleaning device to continue to be used at the lower power level.

[0014] The accumulator can comprise a package of several accumulator cells. Preferably, it is designed as a battery pack. The individual, predetermined cut-off threshold assigned to the current power level is preferably reached when a pack and / or cell voltage of the accumulator is equal to this predetermined cut-off threshold.

[0015] The invention further relates to a method for operating a cleaning device with a battery configured to supply energy to the cleaning device for carrying out a cleaning process, and a control and / or regulating device in which several power levels are stored, wherein each power level is assigned an individual, predetermined cut-off threshold which depends on the load of the respective power level, wherein the method comprises the following steps Operating the cleaning device in one of the power levels, which then represents a current power level, and when the individual, predetermined shutdown threshold of the current power level is reached, switching off the current power level and providing a lower power level.

[0016] Preferably, the step of switching off the current power level and providing a lower power level includes: switching off the cleaning device when the individual, predetermined switch-off threshold of the current power level is reached and then restarting the cleaning device, so that after the restart of the cleaning device a user of the cleaning device can only select a power level lower than the power level current before the restart.

[0017] Alternatively, preferably, the step of switching off the current power level and providing a lower power level features an automatic switch from a current power level to a lower power level.

[0018] In a preferred embodiment, the accumulator supplies energy to a drive unit of the cleaning device, which drives a blower of the cleaning device.

[0019] The cleaning device is preferably a dry and / or wet vacuum cleaner. The cleaning device is to be understood as a power-independent cleaning system that is powered by a battery. The battery is preferably a lithium-ion battery. The cleaning device is preferably designed as a vacuum cleaner. The vacuum cleaner can be any type of vacuum cleaner. Preferably, it is designed as a stick vacuum cleaner.

[0020] The respective individual, predetermined shutdown threshold is preferably an undervoltage threshold of the respective power stage.

[0021] An embodiment of the invention is shown schematically in the drawings and is described in more detail below. It is shown schematically and not to scale. Fig. 1 a sketched representation of a cleaning device according to the invention; Fig. 2 a time course of the voltage of a battery during a discharge process of a cleaning device according to the prior art; Fig. 3 a time course of the voltage during a discharge process of the in Fig. 1 shown accumulator; Fig. 4 a sketched representation of the in Fig. 1 shown accumulator; Fig. 5 shows a pack or cell voltage of the accumulator as a function of the power levels of the in Fig. 1 cleaning device shown; and Fig. 6 a flowchart of a method according to the invention.

[0022] Fig. 1 Figure 1 shows a sketched representation of a cleaning device according to the invention. The cleaning device comprises a battery 1 and a drive unit 2, which is powered by the battery 1. The battery is, for example, a lithium-ion battery. Furthermore, the cleaning device comprises a blower 3, which is driven by the drive unit 2. The cleaning device also includes accessories 4 and a handle 5, which has a switch or button for turning the cleaning device on and off. The accessories 4 can be, for example, a suction tube and / or a floor nozzle / mopping attachment (with or without an electric drive) if the cleaning device is a vacuum cleaner. The cleaning device also includes a control and / or regulating unit (not shown) in which various power levels are stored, which can be selected by a user to perform a cleaning process with different loads or power levels.

[0023] During operation, the user moves the cleaning device across the surface to be cleaned by guiding the accessory 4 across the surface using the handle 5. The accumulator 1 supplies energy to the drive unit 2, which powers the blower 3. The cleaning performance achieved by the user depends on the current power level selected during the cleaning process.

[0024] Fig. 2 Figure 1 shows the voltage profile over time during the discharge process of a battery in a prior art cleaning device. The figure depicts a voltage U as a function of time t. The prior art cleaning device corresponds to the one described in Figure 2. Fig. 1 The cleaning device shown differs in that its control and / or regulating device is configured and designed differently. As shown in Fig.2 As shown, when fully charged, the battery has its maximum voltage Umax, which initially drops to a nominal voltage Unom during discharge. The battery can maintain its nominal voltage Unom relatively constant over an extended discharge period. When the battery is nearly discharged, the voltage drops abruptly, but a minimum voltage Ulimit must not be undercut to prevent permanent damage to the battery. The control and / or regulating device, according to the state of the art, contains a fixed, predetermined cut-off threshold Umin for all power levels Phigh, Plow, at which point the drive unit is switched off, regardless of the current power level at which it is operating. The discharge time from a fully charged battery to the predetermined cut-off threshold Umin determines the operating time of the cleaning device.The fixed predetermined shutdown threshold U min is based on the high power level P (high) according to the state of the art, while for a low power level P (low) there is still a usable residual capacity which is not used according to the state of the art.

[0025] Fig. 3 shows a time course of the voltage during a discharge process of the in Fig. 1 shown accumulator. The one in Fig. 3 Time course of the voltage shown during a discharge process of the in Fig. 1 The accumulator shown corresponds to the one in Fig. 2 The depicted course. However, in contrast to the cleaning device according to the prior art, the cleaning device according to the invention has a control and regulating unit in which each power level P (high), P (low) is assigned an individual, predetermined cut-off threshold Umina, Uminb, which depends on the load of the respective power level P (high) or P (low). The high power level P (high) is assigned an individual, predetermined cut-off threshold Umina, while the low power level P (low) is assigned an individual, predetermined cut-off threshold Uminb, which is lower than the predetermined cut-off threshold Umina and has a voltage difference ΔUmin compared to it.This means that when operating the cleaning device at the low power level P (low), the cleaning device is not switched off at a time ta, but at a time tb, between which there is a time difference Δt, thus gaining further operating time Δt when operating at the low power level P (low).

[0026] Fig. 4 shows a sketched representation of the in Fig. 1 The accumulator shown. Accumulator 1 has an internal resistance Ri. Due to the physical behavior of accumulator 1, a current flow I increases with constant power output, while the voltage level U decreases. Due to the internal resistance Ri, the voltage level at the battery terminals (not shown) of accumulator 1 drops with decreasing power output, such that at the various values ​​shown in Fig. 3 The performance levels shown reach their respective, predetermined shutdown thresholds at different times.

[0027] Fig. 5 shows the pack or cell voltage of the battery as a function of the power levels of the in Fig. 1 cleaning device shown. In this case, the cleaning device has three power levels: a high power level P (high) with a switch-on threshold 40 with a pack voltage or UDC of 21.5 V and a cell voltage of 3.15 V and with an individual, predetermined switch-off threshold 41 UDC of 20 V and a cell voltage of 2.85 V; a medium power level P (medium) with a switch-on threshold 42 with a pack voltage or UDC of 20.75 V and a cell voltage of 2.96 V and with an individual, predetermined switch-off threshold 43 UDC of 19.25 V and a cell voltage of 2.75 V; and a low power level P (low) with a switch-on threshold 44 with a pack voltage or UDC of 20.0 V and a cell voltage of 2.85 V and with an individual, predetermined switch-off threshold 45 UDC of 18.5 V and a cell voltage of 2.64 V.In the control unit, each power level P (high), P (medium), P (low) is assigned an individual, predetermined switch-on threshold 40, 42, 44. The voltage specifications given here (UDC) are exemplary for a 7-cell lithium-ion battery connected in series.

[0028] Fig. 6 shows a flowchart of a method according to the invention. The method is for operating the in Fig. 1 suitable cleaning device shown, which has a display that is in Fig. 6 is represented symbolically. The control unit contains three power levels: a high power level, a medium power level, and a low power level, which correspond to the... Fig. 5 The performance levels shown correspond to those shown.

[0029] The method involves operating the cleaning device in one of the power levels, which then represents a current power level, whereby, when the individual, predetermined shutdown threshold of the current power level is reached, the current power level is switched off and a lower power level is provided.

[0030] To perform a cleaning operation with the cleaning device, step 16 is executed, which involves a user pressing an I / O or input / output button. During operation, step 11 can detect that the battery is empty at any power level when the control unit detects that the battery's state of charge (SoC) is close to 0%. This leads to step 18, in which the display shows that the battery is empty. Also, in step 15, the cleaning device can be switched off at any power level by pressing a symbolically represented I / O or input / output button, which leads to step 17, in which the display is switched off or remains off.

[0031] The procedure begins with a step 14, which involves restarting or switching on the cleaning device without pressing any button. In step 17, the display is off and / or held. If the cleaning device's control unit detects in step 10 that the battery is empty, in step 18 the display indicates that the battery is empty. If step 18 results in a timeout exceeding a predetermined time, step 12 is executed, in which the display is switched off.

[0032] In a first procedure variant, the following steps are performed: The cleaning device is switched off when the individual, predetermined switch-off threshold of the current power level is reached, and then the cleaning device is restarted so that after the restart, a user of the cleaning device can only select a power level lower than the power level active before the restart. If, after step 16, the state of charge (SoC) of the battery is greater than 0% and a pack voltage or...If the battery voltage (UDC) is greater than 20.75 V and a cleaning mode is detected in step 29, step 26 is executed in which a medium power level is displayed. If the UDC is greater than 21.5 V, a symbolically represented button can be pressed to confirm the power selection to the high power level. This leads to step 27 in step 25, in which the high power level is displayed and executed. Otherwise, i.e., if no action is taken, the medium power level is maintained and displayed.If step 16 is executed when the battery's SoC is greater than 0% and UDC is less than 20.75 V, and a cleaning mode is detected in step 29, step 28 is executed in which the low power level is displayed. If UDC is greater than 20.75 V, step 25 confirms the power switch to the medium power level, leading to step 26 in which the medium power level is displayed and executed. Otherwise, i.e., if no action is taken, the low power level is maintained and displayed.

[0033] An alternative procedure is as follows: If the UDC is less than 20.0 V during operation in the high power stage, the medium power stage is automatically set in step 30, starting from step 27, as indicated by a dashed arrow, and the medium power stage is displayed in step 26. If the UDC is less than 19.25 V during operation in the medium power stage, the low power stage is automatically set in step 31, starting from step 26, and the low power stage is displayed in step 28. Reference symbol list

[0034] ΔU Voltage difference Δt Time difference I Current flow R i Internal resistance t, ta , tb Time U Voltage U Limit Umax Maximum voltage Umin , Umina , Uminb Minimum voltage U Nominal Nominal voltage 1 Accumulator 2 Drive unit 3 Blower 4 Accessories 5 Handle 40, 42, 44 Switch-on threshold 41, 43, 45 Switch-off threshold

Claims

1. Cleaning apparatus comprising - a drive unit (2) designed to drive a blower (3) and / or a cleaning actuator system, - an accumulator (1) designed to supply energy to the drive unit (2), and - an open-loop and / or closed-loop control device in which several power levels (P(hoch), P(mittte), P(niedrig)) are stored at which the drive unit (2) is operated in each case by an individual load assigned to the relevant power level (P(hoch), P(mittel), P(niedrig)), characterised in that an individual, predetermined switch-off threshold (Umina, Uminb, 41, 43, 45), which depends on the load of the relevant power level (P(hoch), P(mittel), P(niedrig)), is assigned to each power level (P(hoch), P(mittel), P(niedrig)).

2. Cleaning apparatus according to claim 1, characterised in that the open-loop and / or closed-loop control device is configured and designed to perform, during operation, a change from a present power level to a lower power level by switching off the cleaning apparatus when the individual, predetermined switch-off threshold assigned to the present power level is reached, and subsequently restarting the cleaning apparatus, so that, after the cleaning apparatus is restarted, a user of the cleaning apparatus can select only a power level lower than the power level present before the restart.

3. Cleaning apparatus according to claim 1 or 2, characterised in that an individual, predetermined switch-on threshold (40, 42, 44) is assigned to each power level (P(hoch), P(mittel), P(niedrig)).

4. Cleaning apparatus according to claim 1 or 3, characterised in that the open-loop and / or closed-loop control device is configured and designed to automatically perform a change (30, 31) from a present power level to a lower power level when the individual, predetermined switch-off threshold assigned to the current power level is reached.

5. Method for operating a cleaning apparatus comprising an accumulator (1), which is configured to supply energy to the cleaning apparatus in order to perform a cleaning process, and an open-loop and / or closed-loop control device, in which several power levels (P(hoch), P(mittel), P(niedrig)) are stored, characterised in that an individual, predetermined switch-off threshold (Umina, Uminb, 41, 43, 44), which depends on the load of the relevant power level (P(hoch), P(mittel), P(niedrig)), is assigned to each power level (P(hoch), P(mittel), P(niedrig)), the method comprising operating the cleaning apparatus at one of the power levels (P(hoch), P(mittel), P(niedrig)), which then represents a present power level, and, when the individual, predetermined switch-off threshold of the present power level is reached, comprising switching off the present power level and providing a lower power level.

6. Method according to claim 5, characterised in that the step of switching off the present power level (P(hoch)) and providing a lower power level (P(niedrig)) comprises: switching off the cleaning apparatus when the individual, predetermined switch-off threshold of the present power level is reached and then restarting the cleaning apparatus so that, after the cleaning apparatus is restarted, a user of the cleaning apparatus can select only a power level lower than the power level present prior to the restart.

7. Method according to claim 5, characterised in that the step of switching off the present power level and providing a lower power level comprises an automatic change from the present power level to a lower power level.

8. Method according to any of claims 5 to 7, characterised in that the accumulator (1) supplies energy to a drive unit (2) of the cleaning apparatus, which energy drives a blower (3) of the cleaning apparatus.

9. Cleaning apparatus according to any of claims 1 to 4 or method according to any of claims 5 to 8, characterised in that the particular individual, predetermined switch-off threshold (Umina, Uminb, 41, 43, 45) is an undervoltage threshold of the particular power level (P(hoch), P(mittel), P(niedrig)).

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