vacuum cleaner

Abstract

To provide a vacuum cleaner capable of achieving power saving while stabilizing control of a motor.SOLUTION: A vacuum cleaner includes a motor 12, a rotary cleaning body 11 rotated by the motor 12, and control means for controlling the motor 12. The control means executes at least either decreasing processing or increasing processing for drive power of the motor 12 on the basis of a result of determination on increase or decrease of a load current value or its related value of the motor 12. When the increasing processing is executed within a first time after the decreasing processing by the control means, at least either a change in a criterion of the determination for making the decreasing processing less likely to occur, or a change in a criterion of the determination for making the increasing processing more likely to occur is executed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a vacuum cleaner including a rotary cleaning body rotated by a motor.

Background Art

[0002] Conventionally, as a cleaning tool used in a vacuum cleaner, a so-called active brush structure suction inlet body including a rotary cleaning body and a motor for rotating the rotary cleaning body is known. In such a suction inlet body, dust is once scraped up from the surface to be cleaned by the rotary cleaning body rotated by the force of the motor and then sucked in, so that dust can be efficiently removed from a surface to be cleaned where dust such as carpet is likely to get entangled.

[0003] In consideration of safety and energy saving, it is preferable to suppress or stop the rotation of the rotary cleaning body of the suction inlet body in a state where it is separated from the surface to be cleaned. On the other hand, in a scene where dust removal performance by the suction inlet body is required, such as on a carpet, it is preferable that the rotary cleaning body rotates with sufficient torque. Therefore, when the motor is driving, when a comparison value based on the current consumption of this motor continues to be below a predetermined threshold value for a predetermined time, the driving power of the motor is decreased, and when the comparison value exceeds the predetermined threshold value, such as when the suction inlet body is on the carpet, the driving power of the motor is increased to increase the rotational torque.

[0004] Thus, in the case of a configuration that controls the behavior of the motor based on the fluctuation of the current, the rotation of the rotary cleaning body or the motor is affected by factors such as the deflection of flooring or tatami due to temperature and humidity, the difference in softness of the carpet hair, and the speed and stroke at which the user moves the suction inlet body. It is required to stabilize the control of the driving power of the motor against the fluctuation and difference in the load current value caused by the difference in conditions highly related to the rotational load.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The problem that this invention aims to solve is to provide a vacuum cleaner that can reduce power consumption while stabilizing motor control. [Means for solving the problem]

[0007] The vacuum cleaner of this embodiment comprises a motor, a rotating cleaning body rotated by the motor, and control means for controlling the motor. The control means controls the load current value of the motor or a related value This value is correlated with the current value calculated from the current flowing through the motor. Based on the results of the determination of an increase or decrease, at least one of the following processes is performed: a decrease in the motor's drive power or an increase in the motor's drive power. The reduction process is performed based on the fact that no increase in the load current value or related value occurred within the judgment time. The control means, if an increase process is performed within the first time after a decrease process, will change the judgment criteria to make it less likely for a decrease process to occur, or change the judgment criteria to make it more likely for an increase process to occur. Changes to the judgment criteria to reduce the likelihood of reduction processing include extending the judgment time. . [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing a part of an electric vacuum cleaner according to one embodiment. [Figure 2] This is a block diagram showing some of the internal structures of the same vacuum cleaner. [Figure 3] This is a perspective view showing the same electric vacuum cleaner. [Figure 4] This flowchart shows the control of the same electric vacuum cleaner. [Figure 5] This flowchart shows the control of the electric vacuum cleaner motor when the driving power is low. [Figure 6] This flowchart shows the control of the same vacuum cleaner motor when the driving power is high. [Modes for carrying out the invention]

[0009] One embodiment will be described below with reference to the drawings.

[0010] In Figure 1, 1 is a cleaning tool. The cleaning tool 1, also called a cleaning head, cleans the surface to be cleaned, F, such as a floor. The cleaning tool 1 comprises a case body 10. A dust collection port 100 is formed in the case body 10. A rotating cleaning body 11 is rotatably attached to the case body 10 facing the dust collection port 100. The rotating cleaning body 11 is rotated by a motor 12 to sweep up dust from the surface to be cleaned F. The motor 12 is controlled by a control means 13 shown in Figure 2. Hereafter, the front and rear directions of the cleaning tool 1 shown in Figure 1 are based on the direction as seen from the user when the user is using the cleaning tool 1. Generally, the direction away from the user is considered the front direction, and the direction approaching the user is considered the rear direction. For example, the direction of arrow FR in Figure 1 is the front direction, and the direction of arrow RR is considered the rear direction.

[0011] As shown in Figure 3, the cleaning tool 1 is used in an electric vacuum cleaner CL. In this embodiment, the cleaning tool 1 is applied to a suction-type electric vacuum cleaner CL in which dust is sucked into the separation unit 4 along with air by negative pressure generated by the drive of a suction source 3, such as an electric blower, located in the vacuum cleaner body 2 of the electric vacuum cleaner CL. The electric vacuum cleaner CL may be any type, such as a floor-running type, canister type, stick type, upright type, handheld type, or self-propelled electric vacuum cleaner. In this embodiment, the electric vacuum cleaner CL will be described using a stick-type electric vacuum cleaner as an example. In the illustrated example, the cleaning tool 1 is also called a suction port or floor brush, and is mechanically and fluidly connected to the vacuum cleaner body 2 via an extension tube 5, which is a tubular part, or a connecting tube 14, which is a connecting part connected to the case body 10. Furthermore, in this embodiment, the operation or suction force of the suction source 3, and the on / off switching of the rotation of the rotating cleaning body 11 or motor 12 are set by the user by operating a switch 7 on the handheld operation unit 6 for gripping operation. The vacuum cleaner body 2 is equipped with a main unit control 8 that operates the suction source 3 according to the operation set by the switch 7. The switch 7 or the main unit control 8 is electrically connected to the control means 13. The control means 13 may be located on the cleaning tool 1, but in this embodiment, at least a part of the control means 13 is incorporated into the main unit control 8. The power supply unit B of the electric vacuum cleaner CL is located, for example, on the vacuum cleaner body 2. In this embodiment, the power supply unit B is a battery or a secondary battery, but it is not limited to these, and may be a cord reel device or the like that takes power from an external power source such as a commercial power supply.

[0012] Next, the internal structure of the control means 13 will be described with reference to Figures 1 and 2.

[0013] The control means 13 includes a power variable unit 130 that varies the drive power of the motor 12. The power variable unit 130 may continuously change the drive power of the motor 12 or change it to one of several levels. In this embodiment, the power variable unit 130 is capable of setting the drive power of the motor 12 to one of at least several levels.

[0014] As a method for varying the drive power of the motor 12 by the power variable unit 130, for example, the drive power of the motor 12 is set according to the energizing time of the motor 12 by adjusting the energizing time of the motor 12. As an example, the power variable unit 130 sets the drive power of the motor 12 by using a PWM signal as the control signal to the motor 12, i.e., the applied voltage, and adjusting the duty cycle of the PWM signal. In other words, when the duty cycle of the PWM signal is set to 100%, the drive power of the motor 12 is maximized, and by lowering the duty cycle of the PWM signal, the drive power of the motor 12 is reduced, and the rotational speed and rotational torque of the rotating cleaning body 11 are reduced. In other words, when the power variable unit 130 increases the drive power of the motor 12, it increases the duty cycle, and when it decreases the drive power of the motor 12, it decreases the duty cycle. In this embodiment, the power variable unit 130 has multiple different duty cycles, and by selectively setting the duty cycle of the motor 12's PWM signal to one of these duty cycles, the drive power of the motor 12 can be set to multiple different drive powers.

[0015] The control means 13 or the power variable unit 130 may control the motor 12 to rotate the rotating cleaning body 11 in any direction. For example, the control means 13 or the power variable unit 130 may control the motor 12 so that the rotation direction of the rotating cleaning body 11 is fixed in one direction regardless of the direction of travel of the cleaning tool 1, or it may control the motor 12 so that the rotation direction of the rotating cleaning body 11 switches according to the direction of travel of the cleaning tool 1. In this embodiment, the control means 13 or the power variable unit 130 controls the rotation direction of the motor 12 so that the rotating cleaning body 11 rotates in a direction where the part to be cleaned F is moving from front to back, that is, in the counterclockwise direction shown by arrow X in Figure 1. In other words, in this embodiment, the control means 13 or the power variable unit 130 controls the rotation direction of the motor 12 so that the rotating cleaning body 11 rotates in a direction where it rubs against the part to be cleaned F from front to back. That is, the control means 13 or the power variable unit 130 sets the rotation direction of the motor 12 to a predetermined constant direction. In this embodiment, the rotation direction of the rotating cleaning body 11 is forward rotation or in the correct direction for the forward movement of the cleaning tool 1, that is, a direction that assists the forward movement of the cleaning tool 1, and reverse rotation or in the correct direction for the backward movement of the cleaning tool 1, that is, a direction that imposes a greater load on the backward movement of the cleaning tool 1.

[0016] Furthermore, the control means 13 includes a current detection unit 131 that detects the load current value of the motor 12. The load current value of the motor 12 is a current value that indicates the load state of the rotating cleaning body 11 rotated by the motor 12, and is correlated with the actual current value of the motor 12. The actual current value of the motor 12 is, for example, the average value of current values ​​acquired a predetermined number of times at predetermined time intervals. This actual current value is highly dependent on the duty cycle of the PWM signal of the power variable unit 130. Therefore, in this embodiment, in order to make the load current value independent of the duty cycle of the PWM signal, the actual current value is obtained by dividing the actual current value by the duty cycle of the PWM signal in the power variable unit 130. That is, (load current value) = (actual current value) / (duty cycle). Thus, the load current value in this embodiment is a value calculated from the current value flowing through the motor 12. The detection period T of the load current value by the current detection unit 131 is, for example, 100 ms.

[0017] In the control and determination by the control means 13, a related value of the load current value may be used instead of, or in addition to, the load current value. As the related value of the load current value, values such as the current value itself flowing through the motor 12 and the value obtained by subtracting a predetermined value from the current value flowing through the motor 12 can be considered. This predetermined value is the load current value when the rotational load of the rotary cleaning body 11 or the motor 12 is constant or substantially constant. For example, when the rotary cleaning body 11 is idling, especially when the rotary cleaning body 11 is idled for confirmation during the manufacture of the cleaning tool 1, it is set to half of the load current value of the motor 12 detected at that time. That is, the related value of the load current value is assumed to include a value having a correlation with this current value, calculated from the current value flowing through the motor 12. Hereinafter, the "load current value or its related value" will be simply referred to as the "load current value", and the "rotational load of the rotary cleaning body 11 or the motor 12" will be simply referred to as the "rotational load".

[0018] As an example of the method for detecting the current value of the motor 12 by the current detection unit 131, a current is passed through a resistor with a small resistance value, that is, a so-called shunt resistor, which is a detection element. The potential difference generated across the shunt resistor is amplified and input to an A / D converter, which is a conversion unit, and the output of the A / D converter is captured.

[0019] In this embodiment, the current detection unit 131 has been described as including a current value acquisition unit that has a detection element, an A / D converter, etc. to acquire the current value flowing through the motor 12, an actual current value calculation unit that calculates the actual current value, and a load current value calculation unit that calculates the load current value. However, the current value acquisition unit, the actual current value calculation unit, and the load current value calculation unit may each be configured as separate circuit units, they may be arbitrarily combined, or some of them may form part of other circuit units. That is, the current detection unit 131 is not limited to being integrally provided with the current value acquisition unit, the actual current value calculation unit, and the load current value calculation unit.

[0020] Furthermore, the control means 13 has a storage unit 132 such as a memory. In the present embodiment, the load current value detected by the current detection unit 131 is stored and held in the storage unit 132 each time. The load current value stored in the storage unit 132 may be updated each time a new load current value is detected, or may be held for a predetermined time, and the oldest load current value may be deleted each time a new load current value is detected. In addition, the minimum value and / or maximum value of the load current value are stored in the storage unit 132. The minimum value and the maximum value may be deleted after being held for a predetermined time. Furthermore, various thresholds for determination, determination values, etc. are stored in the storage unit 132. Hereinafter, the minimum value is not limited to only one minimum value, but may be a value sufficiently close to the minimum value, or any one of a plurality of minimum values or peak values of the fluctuating load current value, or an average value of at least any one of those minimum values or peak values. Similarly, the maximum value is not limited to only one maximum value, but may be a value sufficiently close to the maximum value, or any one of a plurality of maximum values or peak values of the fluctuating load current value, or an average value of at least any one of those maximum values or peak values. In addition, various data used for the control by the control means 13, such as other arbitrary thresholds, flags, programs, etc., are stored in the storage unit 132.

[0021] Also, the control means 13 has a determination unit 133. The determination unit 133 determines an increase and a decrease in the load current value based on the load current value detected by the current detection unit 131 and the past load current values stored in the storage unit 132, and determines the state of the cleaning tool 1 or the rotary cleaning body 11 from the result of the determination. Accordingly, the setting of the driving power of the motor 12 by the power variable unit 130 is controlled. The determination by this determination unit 133 will be described later.

[0022] Note that the power supply of the motor 12 and the control means 13 may be provided in the cleaning tool 1, or may be taken from the power supply unit B of the cleaner main body 2.

[0023] Next, the operation of an embodiment will be described.

[0024] During cleaning, the user grasps the handheld control unit 6 and operates the switch 7, causing the main unit control unit 8 to operate the suction source 3. The negative pressure generated by the operation of the suction source 3 acts on the extension tube 5 and cleaning tool 1 via the separation unit 4, drawing dust from the area to be cleaned into the separation unit 4 along with the air through the dust collection port 100. The user moves the cleaning tool 1 back and forth alternately with the handheld control unit 6 while it is placed on the area to be cleaned F, sequentially drawing the dust from the area to be cleaned F into the separation unit 4. The dust-laden air drawn into the separation unit 4 has the dust separated and collected in the separation unit 4. After the suction source 3 is cooled, the air from which the dust has been separated is discharged to the outside of the vacuum cleaner body 2.

[0025] Furthermore, the control means 13 uses the power variable unit 130 to activate the motor 12 of the cleaning tool 1, thereby rotating the rotating cleaning body 11. The rotation of the rotating cleaning body 11 sweeps up dust from the area to be cleaned F, and this swept-up dust is sucked into the separation unit 4 by the negative pressure acting on the dust collection port 100. The user can stop the rotation of the rotating cleaning body 11 of the cleaning tool 1 by operating the switch 7 as needed, for example, to prevent objects from getting caught in the rotating cleaning body 11.

[0026] The control means 13 may arbitrarily set the drive power of the motor 12 when it is started. However, in this embodiment, as an example, when the motor 12 is started, i.e., when the rotating cleaning body 11 is started, it is unclear whether the cleaning tool 1 is in contact with the part to be cleaned F. Therefore, considering greater safety, the control means 13 preferably starts the motor 12 with a relatively small drive power using the power variable unit 130. This causes the rotating cleaning body 11 to rotate at a low speed. Then, when the determination unit 133 determines that a predetermined increase condition has been met while the drive power of the motor 12 is relatively small, the control means 13 increases the drive power of the motor 12 using the power variable unit 130, causing the rotating cleaning body 11 to rotate at a high speed. This control is hereinafter referred to as the increase process or power increase control. Furthermore, when the determination unit 133 determines that a predetermined decrease condition has been met while the drive power of the motor 12 is relatively large, the control means 13 decreases the drive power of the motor 12 using the power variable unit 130, causing the rotating cleaning body 11 to rotate at a low speed or stop. This control is hereafter referred to as reduction processing or power reduction control.

[0027] The reduction process described above is a control aimed at reducing the rotational speed or rotational torque of the rotating cleaning body 11 by reducing the rotational speed of the motor 12 from a relatively high state. The conditions for performing the reduction process can be arbitrarily set based on the results of the determination of an increase and decrease in the load current value of the motor 12, but in this embodiment, the reduction process is performed based on the fact that it was not determined that the load current value of the motor 12 increased within a predetermined first determination time, that is, that an increase in the load current value of the motor 12 was not determined within at least the first determination time. This condition corresponds to the detection that the part to be cleaned F is a wooden floor or the like with a small rotational load, that the cleaning tool 1 did not move on the part to be cleaned F, or that the cleaning tool 1 or the rotating cleaning body 11 is away from the part to be cleaned F.

[0028] Furthermore, the above-described increase process is a control aimed at increasing the rotational speed or rotational torque of the rotating cleaning body 11 by increasing the rotational speed of the motor 12 from a relatively low state. The conditions for performing the increase process can be arbitrarily set based on the results of the determination of an increase and decrease in the load current value of the motor 12, but in this embodiment, the increase process is performed based on at least the determination of an increase in the load current value of the motor 12, followed by a determination of a decrease in the load current value, and then a determination of a further increase in the load current value; that is, at least an increase in the load current value of the motor 12 is determined, followed by a determination of a decrease in the load current value of the motor 12 within a second determination time, and then a determination of an increase in the load current value of the motor 12 within a third determination time. This condition focuses on the operation in which the user moves the cleaning tool 1 back and forth while it is in contact with the part to be cleaned F during cleaning, and corresponds to the detection that the cleaning tool 1 has moved forward, backward, and forward on the part to be cleaned F such as a carpet.

[0029] Here, the typical movement speed of the cleaning tool 1 by a typical user is 0.5 m / second, as specified in the JIS and other prescribed standards. The time it takes for a typical user to move the cleaning tool 1 forward from start to stop is approximately 0.8 to 1 second, and the time it takes for the cleaning tool 1 to move backward from start to stop or forward again is approximately 1 to 1.5 seconds. For example, the first judgment time is set as the time required for the cleaning tool 1 to complete one round trip, with an initial value of 2.0 seconds. The second and third judgment times may be the same or different, but for example, the second judgment time is set as 0.8 seconds, which is the time from start to stop, and the third judgment time is set as 1.0 second, which is the time from start to stop or forward again, with an initial value of 1.0 second.

[0030] In this embodiment, "reducing the drive power of the motor 12" or "setting it to a relatively small drive power" in the reduction process means that the control means 13 sets the drive power of the motor 12 to a predetermined first drive power of 0 or more using the power variable unit 130. The first drive power is the relatively smallest of the multiple drive powers that can be set by the power variable unit 130, or the drive power that results in a low rotational speed that is safe even if the user touches the rotating cleaning body 11. If the drive power of the motor 12 is at the first drive power and the determination conditions for the reduction process are met, the drive power of the motor 12 will be maintained as is. The first drive power set by the reduction process may differ depending on whether the part to be cleaned F is a wooden floor or the like with a small rotational load, whether the cleaning tool 1 did not move on the part to be cleaned F, or whether the cleaning tool 1 or the rotating cleaning body 11 is away from the part to be cleaned F, or any two of these may be equal and one of them may be different.

[0031] Similarly, in this embodiment, "increasing the drive power of motor 12" or "setting to a relatively large drive power" in the increase process means that the control means 13 sets the drive power of motor 12 to a predetermined second drive power with a duty cycle of 100% or less using the power variable unit 130. The second drive power is the relatively larger of the multiple drive powers that can be set by the power variable unit 130, and is greater than the first drive power. In this embodiment, the power variable unit 130 sets the duty cycle of the PWM signal for the second drive power to, for example, 100%. Therefore, if the drive power of motor 12 is at the second drive power and the determination condition for the increase process is met, the drive power of motor 12 will be maintained as is.

[0032] In this embodiment, the determination of an increase or decrease in the load current value of the motor 12 is performed by the determination unit 133 based on the fluctuation in the load current value of the motor 12 detected by the current detection unit 131 of the control means 13. Specifically, the control means 13 determines whether the load current value of the motor 12 has increased or decreased in the determination unit 133 by comparing the magnitude of a predetermined load current value of the motor 12 detected by the current detection unit 131, and / or a value calculated from the predetermined load current value, with a predetermined threshold value.

[0033] In this embodiment, the "predetermined load current value" refers to the most recent load current value within a predetermined short time from the time of determination, and preferably the latest load current value is used, but it is not limited to this, and the load current value immediately preceding the latest load current value, that is, the latest load current value stored in the storage unit 132, that is, the load current value from one detection cycle T seconds before the time of determination, may also be used. Furthermore, the immediately preceding load current value is the load current value closest to the predetermined load current value among the load current values ​​stored in the storage unit 132, that is, the load current value from the detection cycle T seconds before the predetermined load current value, but it is not limited to this, and a past load current value within a sufficiently short predetermined time, such as 2T seconds or 3T seconds before the predetermined load current value, may be used, or a value calculated from multiple immediately preceding load current values, such as the average value of load current values ​​within a predetermined time from the predetermined load current value, may also be used.

[0034] Furthermore, in this embodiment, the value calculated from the load current value is a value calculated based on a predetermined load current value and the load current value immediately preceding it. This calculated value is, for example, the difference between the predetermined load current value and the load current value immediately preceding it, and / or the ratio between the predetermined load current value and the load current value immediately preceding it. In other words, this calculated value is the amount of change in the load current value, and / or the ratio of the change in the load current value.

[0035] The control means 13 then determines in the determination unit 133 that the load current value has increased in at least one of the following cases (1-a) to (1-c).

[0036] (1-a) When the load current value of the motor 12 detected by the current detection unit 131 becomes greater than a predetermined increase threshold within a predetermined increase detection time.

[0037] (1-b) When the absolute difference between the load current value of the motor 12 detected by the current detection unit 131 and the minimum load current value stored in the storage unit 132 within a predetermined increase detection time in the past, i.e., the amount of change, becomes greater than a predetermined increase threshold.

[0038] (1-c) When the ratio of the load current value of the motor 12 detected by the current detection unit 131 to the minimum load current value stored in the storage unit 132 within a predetermined increase detection time in the past, i.e., the fluctuation ratio, becomes greater than a predetermined increase threshold.

[0039] Similarly, the control means 13 determines in the determination unit 133 that the load current value has decreased in at least one of the following cases (2-a) to (2-c).

[0040] (2) When the load current value of the motor 12 detected by the current detection unit 131 falls below a predetermined decrease threshold within a predetermined decrease detection time.

[0041] (2) When the absolute difference between the load current value of the motor 12 detected by the current detection unit 131 and the maximum value of the load current value stored in the storage unit 132 within a predetermined past decrease detection time, i.e., the amount of fluctuation, becomes greater than a predetermined decrease threshold.

[0042] (2-c) When the ratio of the maximum value of the load current value stored in the memory unit 132 within a predetermined past decrease detection time to the load current value of the motor 12 detected by the current detection unit 131, i.e., the fluctuation ratio, becomes smaller than a predetermined decrease threshold.

[0043] The increase detection time and decrease detection time are predetermined short periods of time less than or equal to the first, second, and third judgment times, respectively. The increase detection time and decrease detection time may be the same or different. Also, the increase threshold and decrease threshold may have the same or different absolute values.

[0044] Here, the load current value of the motor 12 includes factors that have little correlation with the rotational load and factors that have a high correlation with the rotational load. Factors that have little correlation with the rotational load include variations in the current value of the motor 12, the internal temperature of the motor 12, and the effects of aging deterioration due to hair entanglement in the rotating cleaning body 11, etc. In the control means 13, in the decrease and increase processing, as described above, the determination unit 133 makes a determination of decrease and increase in the load current value based on a comparison of the fluctuation of the load current value of the motor 12 with the decrease threshold and increase threshold, thereby eliminating factors that have little correlation with the rotational load to some extent and improving the accuracy of the determination of decrease and increase.

[0045] On the other hand, factors that are highly related to the rotational load include, if the area to be cleaned F is a wooden floor or tatami mat, the deflection of these materials due to temperature and humidity; if the area to be cleaned F is a carpet, the difference in the softness of the fibers; and the speed and stroke at which the user moves the cleaning tool 1. Fluctuations in the load current value of the motor 12 due to these factors can affect the decrease and increase judgments. If the decrease and increase judgments of the load current value of the motor 12 are affected, it is conceivable that the control of the drive power of the motor 12 will become unstable, as the decrease and increase processes may be performed at times that are unnecessary for the user, or the decrease and increase processes may be repeated in a short period of time.

[0046] For example, when cleaning a surface F such as a carpet, the load current value fluctuates significantly. Generally, once the motor 12's drive power is set to a high level, that is, the rotational speed of the rotating cleaning body 11 is set to a high level, users often wish to maintain that state. However, because carpets and the like have considerable rotational resistance, the load current value of the motor 12 fluctuates drastically, and it is expected that the control means 13 will perform a decrease process and then an increase process relatively quickly based on the result of its judgment of the increase and decrease in the load current value. In other words, if the control means 13 performs an increase process immediately after a decrease process, it is assumed that the situation does not warrant reducing the drive power of the motor 12 or the rotational speed of the rotating cleaning body 11, or that the control means 13 performed the decrease process because the user is moving the cleaning tool 1 slowly, causing the first judgment time to elapse faster than the cleaning tool 1 can complete a back-and-forth motion. Furthermore, when moving the cleaning tool 1 back and forth, the moment when the load current value of the motor 12 is highest, i.e., the peak, is the moment when the cleaning tool 1 is closest to the user, on the near side. At this position, the cleaning tool 1 changes from reverse to forward, resulting in the highest acceleration of the cleaning tool 1. This means that the force moving the cleaning tool 1 forward is strongest, and the force pressing the cleaning tool 1 against the part to be cleaned F is also strongest. Therefore, when the cleaning tool 1 is moved slowly, the force moving the cleaning tool 1 forward also weakens, and the peak load current value of the motor 12 tends to be lower.

[0047] Therefore, if the control means 13 performs an increase process within a predetermined first time after a decrease process, it changes the criteria for determining an increase and / or decrease in the load current value in the determination unit 133 in order to make it less likely for a decrease process to occur and / or to make it more likely for an increase process to occur. That is, the control means 13 tightens the criteria for determining an increase and / or decrease in the load current value in the determination unit 133 for performing a decrease process, and / or relaxes the criteria for determining an increase and / or decrease in the load current value in the determination unit 133 for performing an increase process. Hereinafter, the "criteria for determining an increase and / or decrease in the load current value" will simply be referred to as the "criteria".

[0048] The first time is assumed to be the time after the decrease process when the transient current of the motor 12 settles down and the increase process can be performed thereafter. The first time is longer than each of the first to third determination times, and in this embodiment, it is longer than the sum of the first to third determination times. In this embodiment, the increase process is performed when the determination unit 133 detects one and a half forward, backward, and forward movements of the cleaning tool 1 based on the load current value of the motor 12. Therefore, if the increase process is performed between the decrease process and the cleaning tool 1 has completed twice that number of movements, or three, it will be determined that the timing of the increase process after the decrease process is too early. For this reason, the first time is a multiple of the detection period T, and is preferably about 5 to 10 seconds.

[0049] This configuration prevents unnecessary repetition of reduction and increase processes in a short period of time, for example, when a user slowly moves the cleaning tool 1 over a surface F with a high rotational load, such as a carpet. Therefore, while stabilizing the control of the motor 12, power saving is possible by performing reduction or increase processes only when necessary.

[0050] For example, changes to the criteria for reducing the likelihood of a decrease include extending the first decision time and / or reducing the absolute value of the increase threshold.

[0051] For example, extending the first determination time increases the opportunities for the control means 13 to determine in the determination unit 133 that the load current value of the motor 12 has increased, making it easier to determine that the load current value has increased. Similarly, reducing the absolute value of the increase threshold makes it easier for the load current value, or the increase in its fluctuation amount or fluctuation ratio, to exceed the threshold even if it is relatively small, making it easier to determine that the load current value has increased. As a result, the situation in which the control means 13 does not determine an increase within the first determination time in the determination unit 133 is relatively reduced, making it less likely for a decrease to occur.

[0052] Thus, by changing the judgment criteria to make reduction processing less likely, including extending the first judgment time, the opportunities to determine an increase in the load current value can be increased by extending the first judgment time, making it easier to make reduction processing less likely.

[0053] Furthermore, by changing the judgment criteria to make it less likely for a decrease to occur, including reducing the absolute value of the increase threshold, an increase judgment will be more likely to occur even if the load current value, its fluctuation amount, or fluctuation ratio does not increase significantly, thus making it less likely for a decrease to occur.

[0054] Furthermore, as an example, changes to the criteria for making an increase more likely include reducing the absolute value of the increase threshold, and / or extending the second judgment time, which is the deadline for determining whether a decrease judgment is made from an increase judgment of the load current value, and / or the third judgment time, which is the deadline for determining whether a re-increase judgment is made from a decrease judgment of the load current value.

[0055] For example, reducing the absolute value of the increase threshold makes it easier for the load current value, or its fluctuation amount or fluctuation ratio, to exceed the increase threshold even if the increase is relatively small, thus making it easier to determine that the load current value has increased. Also, for example, extending the second and / or third determination time increases the opportunities for the control means 13 to determine in the determination unit 133 that the load current value of the motor 12 has decreased and / or that the load current value of the motor 12 has increased, thus making it easier to determine that the load current value has decreased and / or increased. Furthermore, regarding the decrease threshold, increasing the absolute value of the decrease threshold with respect to the load current value or its fluctuation ratio makes it easier for the decrease in the load current value or its fluctuation ratio to fall below the decrease threshold even if it is relatively small, and decreasing the absolute value of the decrease threshold with respect to the load current fluctuation amount makes it easier for the absolute value to exceed the decrease threshold even if the decrease in the load current fluctuation amount is relatively small, thus making it easier to determine that the load current value has decreased. As a result, the control means 13 has more opportunities to determine in the determination unit 133 that the load current value has increased, decreased, and then increased again, thus making it easier for an increase process to occur.

[0056] Thus, in a control means 13 that performs an increase process based on determining an increase in the load current value, then determining a decrease, and then determining an increase again, changing the determination criteria to make the increase process more likely to occur includes extending at least one of the second determination time and the third determination time, thereby increasing the opportunities to determine a decrease after determining an increase in the load current, and / or to determine an increase after determining a decrease, and thus making the increase process more likely to occur.

[0057] By changing the criteria for triggering an increase, including reducing the absolute value of the increase threshold, an increase can be triggered even if the load current value, its fluctuation amount, or fluctuation ratio does not increase significantly, thus making it easier to trigger an increase.

[0058] Furthermore, by changing the criteria for determining whether an increase is likely to occur, including increasing the absolute value of the decrease threshold compared with the load current value or its fluctuation ratio, and / or decreasing the absolute value of the decrease threshold compared with the amount of change in the load current value, a decrease determination will be more likely to occur even if the load current value, its fluctuation amount, or fluctuation ratio does not decrease significantly, thus making it easier to determine whether an increase is likely to occur.

[0059] Furthermore, when cleaning a surface F such as a wooden floor or tatami mat, the fluctuation in the load current value is small, and generally, once the motor 12's drive power is set to a low state, i.e., the rotational speed of the rotating cleaning body 11 is set to a low state, users often wish to maintain that state. However, if the wooden floor is in a high-temperature, high-humidity state, or if the tatami mat is old, it is expected that the control means 13 will increase the load due to the influence of the rotational load. In these cases, it is expected that the user will temporarily stop the cleaning tool 1 on the surface F to be cleaned and observe it, and even if they do not stop it, in the case of a surface F such as a wooden floor or tatami mat, the increase or decrease in the motor 12's load current value is not large, so it is expected that the control means 13 will increase the load current value and then decrease it relatively quickly based on the result of the judgment of the increase and decrease in the load current value. In other words, if the control means 13 increases the load current value and then immediately decreases it, it is assumed that the situation does not warrant increasing the drive power of the motor 12 or the rotational speed of the rotating cleaning body 11.

[0060] Therefore, if a decrease process is performed within a predetermined second time after an increase process, the control means 13 changes the judgment criteria to make it less likely for an increase process to occur and / or to make it more likely for a decrease process to occur. That is, the control means 13 tightens the judgment criteria for performing an increase process and / or relaxes the judgment criteria for performing a decrease process. The second time is a multiple of the detection period T, and is preferably about 2 to 3 times the first judgment time, for example, 5 to 10 seconds is preferred.

[0061] This configuration prevents unnecessary repetition of increasing and decreasing power levels in short intervals, for example, when a user is cleaning a surface F such as a wooden floor or old tatami mats that are hot and humid. Therefore, power saving is possible by stabilizing the control of the motor 12 and performing decreasing or increasing power levels only when necessary.

[0062] On the other hand, when cleaning a normal wooden floor or tatami mat, if the above-mentioned change in the judgment criteria makes it less likely to cause a decrease and / or more likely to cause an increase, then even if the load current value and its fluctuations are small, it may be difficult to reduce the drive power of the motor 12 from a relatively large state to a small state, and there is a concern that the drive power may be unnecessarily maintained in a relatively large state.

[0063] Therefore, if the control means 13 does not perform a decrease process within a predetermined third time that is longer than the first time, it is preferable to change the judgment criteria to make the decrease process more likely to occur, and change the judgment criteria to make the increase process less likely to occur. For example, in this embodiment, the control means 13 cancels the change in the judgment criteria that makes the decrease process less likely to occur, and / or the change in the judgment criteria that makes the increase process more likely to occur. In other words, in this embodiment, if the change in the judgment criteria that makes the decrease process less likely to occur, and / or the change in the judgment criteria that makes the increase process more likely to occur is performed once, it is reset by one step, and if it is performed multiple times, it is reset by one or more steps so that the judgment criteria do not exceed the initial state or initial value. In this case, the third time is a multiple of the detection period T, and is preferably a time that is sufficiently longer than the first time, i.e., the time during which the increase process is expected to be performed again on the part to be cleaned F such as a carpet, and is short enough that the user can continue cleaning without lifting the cleaning tool 1 or the rotating cleaning body 11 from the part to be cleaned F, for example, it is set to about 20 to 30 seconds.

[0064] This configuration allows for energy savings by appropriately reducing power consumption when, for example, a user cleans a surface F such as a regular wooden floor or tatami mat.

[0065] Furthermore, when cleaning a carpet or other surface F by moving the cleaning tool 1 at a typical speed, if the above-mentioned changes to the judgment criteria make it less likely to cause an increase in processing and / or more likely to cause a decrease in processing, it is a concern that the drive power of the motor 12 will not increase from a relatively small state to a large state, even if the load current value and its fluctuations are large, and that the drive power will be unnecessarily maintained in a relatively small state.

[0066] Therefore, if the control means 13 does not perform an increase process within a predetermined fourth time that is longer than the second time, it is preferable to change the judgment criteria to make it less likely for a decrease process to occur, or to change the judgment criteria to make it more likely for an increase process to occur. For example, in this embodiment, the control means 13 cancels the change in the judgment criteria that makes it less likely for an increase process to occur, and / or the change in the judgment criteria that makes it more likely for a decrease process to occur. In other words, in this embodiment, if the change in the judgment criteria that makes it less likely for an increase process to occur, and / or the change in the judgment criteria that makes it more likely for a decrease process to occur, is performed once, it is reset by one step, and if it is performed multiple times, it is reset by one or more steps, so that the judgment criteria do not exceed the initial state or initial value. In this case, the fourth time is a multiple of the detection period T, and is preferably a time that is sufficiently longer than the second time, i.e., the time during which a decrease process is expected to be performed again if the area to be cleaned F is such as a wooden floor, and is short enough that the user can continue cleaning without lifting the cleaning tool 1 from the area to be cleaned F, for example, it is set to about 20 to 30 seconds.

[0067] With this configuration, for example, when a user moves the cleaning tool 1 at a normal speed on a surface to be cleaned, such as a carpet, the increased processing can be appropriately performed to ensure dust removal performance.

[0068] For example, changes to the criteria for making a decrease more likely include shortening the first determination time and / or increasing the absolute value of the increase threshold.

[0069] For example, shortening the first determination time reduces the opportunities for the control means 13 to determine in the determination unit 133 that the load current value of the motor 12 has increased, making it less likely for an increase in the load current value to be detected. Similarly, for example, increasing the absolute value of the increase threshold makes it less likely for the increase in the load current value, or its fluctuation amount or fluctuation ratio, to exceed the increase threshold even if the increase is relatively large, making it less likely for an increase in the load current value to be detected. As a result, the situation in which the control means 13 does not determine an increase within the first determination time in the determination unit 133 becomes relatively more frequent, making it more likely for a decrease to occur.

[0070] Thus, in a control means 13 that performs a reduction process based on the fact that no increase in the load current value was determined within at least a predetermined first determination time, changing the determination criteria to make the reduction process more likely to occur includes shortening the first determination time. By shortening the first determination time, the opportunities to determine an increase in the load current value can be reduced, making the reduction process easier to perform.

[0071] By changing the criteria for triggering a decrease, including increasing the absolute value of the increase threshold, it becomes less likely for an increase to be detected even if the load current value, its fluctuation amount, or fluctuation ratio increases significantly, thus making it easier for a decrease to occur.

[0072] Furthermore, changes to the judgment criteria to reduce the likelihood of increased processing include raising the absolute value of the increase threshold, and / or shortening the second and / or third judgment times.

[0073] For example, increasing the absolute value of the increase threshold makes it less likely for the load current value, or its fluctuation amount or fluctuation ratio, to exceed the increase threshold even if the increase is relatively large, making it less likely for an increase in the load current value to be detected. Also, for example, shortening the second and / or third detection time reduces the opportunities for the control means 13 to determine that the load current value of the motor 12 has decreased and / or that the load current value of the motor 12 has increased, making it less likely for a decrease in the load current value to be detected and / or an increase in. Regarding the decrease threshold, reducing the absolute value of the decrease threshold makes it less likely for the load current value, or its fluctuation amount or fluctuation ratio, to fall below the increase threshold even if the decrease is relatively large, making it less likely for a decrease in the load current value to be detected. Furthermore, regarding the decrease threshold, reducing the absolute value of the decrease threshold with respect to the load current value or its fluctuation ratio makes it less likely for the load current value, or its fluctuation ratio, to fall below the decrease threshold even if the decrease is relatively large, and increasing the absolute value of the decrease threshold with respect to the load current fluctuation amount makes it less likely for the absolute value to exceed the decrease threshold even if the decrease in the load current fluctuation amount is relatively large, making it less likely for a decrease in the load current value to be detected. Therefore, the control means 13 reduces the number of situations in the determination unit 133 where it determines that the load current value has increased, then decreased, and then increased again, making it less likely for an increase process to occur.

[0074] Thus, by changing the criteria for determining the increase, including raising the absolute value of the increase threshold, it becomes less likely for an increase to be detected even if the load current value, its fluctuation amount, or fluctuation ratio increases significantly, thus reducing the likelihood of an increase being detected.

[0075] In a control means 13 in which an increase process is performed based on determining an increase in the load current value, then determining a decrease, and then determining an increase again, the change in the determination criteria to make the increase process less likely to occur includes shortening at least one of the second determination time and the third determination time, thereby reducing the opportunities to determine a decrease after determining an increase in the load current, and / or to determine an increase after determining a decrease, and thus making the increase process less likely to occur.

[0076] The reduction and / or increase in the absolute value of the above-mentioned decrease threshold or increase threshold may be selected from a number of fixed values ​​using a pre-stored table, or calculated using a predetermined function. Similarly, the reduction and / or extension of each judgment time may be selected from a number of fixed values ​​using a pre-stored table, or calculated using a predetermined function.

[0077] The above control will be explained with reference to the flowcharts shown in Figures 4 to 6.

[0078] As shown in Figure 4, when the vacuum cleaner CL is started, in step S1, the control means 13 uses the power variable unit 130 to set the drive power P of the motor 12 to either a relatively small first drive power PL or a relatively large second drive power PH. In addition, the flags F_L, which indicate whether the power state of the motor 12 is at the first drive power PL, and F_H, which indicates whether the power state of the motor 12 is at the second drive power PH, are set to False.

[0079] Next, in step S2, the control means 13 determines the drive power P of the motor 12 using the determination unit 133. If it is determined in step S2 that the drive power P of the motor 12 is the first drive power PL, the process proceeds to the first determination control in step S3. If it is determined that the drive power P of the motor 12 is the second drive power PH, the process proceeds to the second determination control in step S4. If it is determined that the drive power P of the motor 12 is any other drive power, the process proceeds directly to step S2. Once the processing in steps S3 and S4 is completed, the process proceeds to step S2. The processing in steps S2 to S4 is performed at each detection cycle T.

[0080] Figure 5 shows the first determination control. First, in step S11, the control means 13 sets the flag F_L to True. Next, in step S12, the control means 13 uses the determination unit 133 to determine whether the timer T_L, which indicates the driving time at the first drive power PL, is less than or equal to the third time T3. If in step S12 it is determined that the timer T_L is less than or equal to the third time T3, that is, if the result of step S12 is YES, then in step S13 the control means 13 increments the timer T_L by 1 and proceeds to step S14. Since the first determination control is performed every detection cycle T, one count of the timer T_L corresponds to one detection cycle T. In other words, the timer T_L is a multiple of the detection cycle T. Also, if in step S12 it is determined that the timer T_L is not less than or equal to the third time T3, that is, if the result of step S12 is NO, the process proceeds directly to step S14.

[0081] In step S14, the control means 13 determines, using the determination unit 133, whether the drive power P of the motor 12 has transitioned from the first drive power PL to the second drive power PH. If, in step S14, the control means 13 determines, using the determination unit 133, that is, if the result of step S14 is YES, then in step S15, the control means 13 determines, using the determination unit 133, whether the flag F_H is True and whether the timer T_L is less than or equal to the first time T1.

[0082] In step S15, if it is determined that flag F_H is True and timer T_L is less than or equal to the first time T1, that is, if step S15 is YES, it is determined that the drive power P of motor 12 has fluctuated in a short time from second drive power PH → first drive power PL → second drive power PH, and in step S16, the control means 13 changes the determination criteria so that a decrease is less likely to occur and / or an increase is more likely to occur, and proceeds to step S17. Also, in step S15, if it is determined that flag F_H is not True and / or timer T_L is not less than or equal to the first time T1, that is, if step S15 is NO, the process proceeds directly to step S17.

[0083] Then, in step S17, the control means 13 sets timer T_L and timer T_H, which indicates the driving time at the second drive power PH, to 0, and terminates the first determination control.

[0084] On the other hand, if in step S14 it is determined that the drive power P of the motor 12 has not transitioned from the first drive power PL to the second drive power PH, that is, if the result of step S14 is NO, then in step S18 the control means 13 determines, using the determination unit 133, whether or not the timer T_L has reached the third time T3. If in step S18 it is determined that the timer T_L has reached the third time T3, that is, if the result of step S18 is YES, it is determined that the decrease process has not occurred for a long time, and in step S19 the control means 13 changes the determination criteria to make the decrease process more likely to occur and / or the increase process less likely to occur, and terminates the first determination control. Also, if in step S18 it is determined that the timer T_L has not reached the third time T3, that is, if the result of step S18 is NO, the first determination control is terminated as is.

[0085] Figure 6 shows the second determination control. First, in step S21, the control means 13 sets the flag F_H to True. Next, in step S22, the control means 13 uses the determination unit 133 to determine whether or not the timer T_H is less than or equal to the fourth time T4. If, in step S22, it is determined that the timer T_H is less than or equal to the fourth time T4, that is, if the result of step S22 is YES, then in step S23, the control means 13 increments the timer T_H by 1 and proceeds to step S24. Since the second determination control is performed every detection cycle T, one count of the timer T_H corresponds to one detection cycle T. In other words, the timer T_H is a multiple of the detection cycle T. Also, if, in step S22, it is determined that the timer T_H is not less than or equal to the fourth time T4, that is, if the result of step S22 is NO, the process proceeds directly to step S24.

[0086] In step S24, the control means 13 determines, using the determination unit 133, whether the drive power P of the motor 12 has transitioned from the second drive power PH to the first drive power PL. If, in step S24, the control means 13 determines, using the determination unit 133, that is, if the result of step S24 is YES, then in step S25, the control means 13 determines, using the determination unit 133, whether the flag F_L is True and whether the timer T_H is less than or equal to the second time T2.

[0087] In step S25, if it is determined that flag F_L is True and timer T_H is less than or equal to the second time T2, that is, if step S25 is YES, it is determined that the drive power P of motor 12 has fluctuated in a short period of time from first drive power PL → second drive power PH → first drive power PL. In step S26, the control means 13 changes the determination criteria so that an increase is less likely to occur and / or a decrease is more likely to occur, and proceeds to step S27. Also, in step S25, if it is determined that flag F_L is not True and / or timer T_H is not less than or equal to the second time T2, that is, if step S25 is NO, the process proceeds directly to step S27.

[0088] Then, in step S27, the control means 13 sets timer T_L and timer T_H to 0, and terminates the second determination control.

[0089] On the other hand, if in step S24 it is determined that the drive power P of the motor 12 has not transitioned from the second drive power PH to the first drive power PL, that is, if the answer to step S24 is NO, then in step S28 the control means 13 determines, using the determination unit 133, whether or not the timer T_H has reached the fourth time T4. If in step S28 it is determined that the timer T_H has reached the fourth time T4, that is, if the answer to step S28 is YES, it is determined that no increase processing occurred for a long time, and in step S29 the control means 13 changes the determination criteria to make increase processing more likely and / or decrease processing less likely, and then terminates the second determination control. Also, if in step S28 it is determined that the timer T_H has not reached the fourth time T4, that is, if the answer to step S28 is NO, then the second determination control is terminated as is.

[0090] Preferably, the control means 13 may also store a record in the storage unit 132 or the like of the extent to which the criteria for judgment have been tightened and / or relaxed, and based on this record, set the conditions at the time cleaning is started, i.e., when the operation of the electric vacuum cleaner CL is started. In this way, it becomes possible to drive the motor 12 under conditions suitable for the user's needs from the start of cleaning.

[0091] The increase process may be performed, for example, based on the determination of an increase in the load current value of motor 12 followed by a determination of a decrease in the load current value; that is, the determination of an increase in the load current value of motor 12, and then the determination of a decrease in the load current value of motor 12 within a predetermined second determination time. This condition focuses on the action of the user moving the cleaning tool 1 back and forth while in contact with the part to be cleaned F during cleaning, and corresponds to the detection that the cleaning tool 1 has moved forward and backward on the part to be cleaned F, such as a carpet. In this case, the change in the determination criteria to make the increase process more likely may be an extension of the second determination time, and the change in the determination criteria to make the increase process less likely may be a shortening of the second determination time.

[0092] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention to these embodiments. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0093] 11 Rotating Cleaning Body 12 motors 13 Control means CL Electric Vacuum Cleaner

Claims

1. Motor and, A rotating cleaning body rotated by the motor, The motor is controlled by a control means, The control means performs at least one of the following processes for decreasing or increasing the drive power of the motor, based on the result of determining whether an increase or decrease has occurred in a value correlated with the current value calculated from the load current value of the motor or a related value, the current value flowing through the motor. The aforementioned reduction process is performed based on the fact that no increase in the load current value or the related value occurred within the determination time, If the increase process is performed within a predetermined time of less than 20 seconds after the decrease process, the control means performs at least one of the following: a change in the determination criteria to make the decrease process less likely to occur, and a change in the determination criteria to make the increase process more likely to occur. The change in the determination criteria for the determination to make the aforementioned reduction process less likely to occur includes extending the determination time. A vacuum cleaner characterized by the following features.

2. Motor and, A rotating cleaning body rotated by the motor, The motor is controlled by a control means, The control means performs at least one of the following processes for decreasing or increasing the drive power of the motor, based on the result of determining whether an increase or decrease has occurred in a value correlated with the current value calculated from the load current value of the motor or a related value, the current value flowing through the motor. The aforementioned reduction process is performed based on the fact that no increase in the load current value or the related value occurred within the determination time, If the decrease process is performed within a second time, which is a predetermined time of less than 20 seconds, after the increase process, the control means performs at least one of the following: a change in the determination criteria for the determination to make the decrease process more likely to occur, and a change in the determination criteria for the determination to make the increase process less likely to occur. The change in the determination criteria for the determination to facilitate the reduction process includes shortening the determination time. A vacuum cleaner characterized by the following features.

3. If the decrease process is performed within a predetermined second time of less than 20 seconds after the increase process, the control means will perform at least one of the following: change the criteria for the determination to make the decrease process more likely to occur, or change the criteria for the determination to make the increase process less likely to occur. The electric vacuum cleaner according to feature 1.

4. If the control means does not perform the reduction process within a time longer than the first time, it performs at least one of the following: changing the criteria for the determination to make the reduction process more likely to occur, or changing the criteria for the determination to make the increase process less likely to occur. The electric vacuum cleaner according to feature 1.

5. If the increase process is not performed within a time longer than the second time, the control means will perform at least one of the following: change the criteria for the determination to make the decrease process less likely to occur, or change the criteria for the determination to make the increase process more likely to occur. The electric vacuum cleaner according to feature 2.

6. The reduction process is performed based on a comparison of at least one of the following with a threshold value: the load current value or the related value, the amount of change in the load current value or the related value, and the ratio of the change in the load current value or the related value. The change in the determination criteria for the determination to make the aforementioned reduction process less likely to occur includes reducing the absolute value of the threshold. The electric vacuum cleaner according to claim 1, 3, or 5, characterized by the features described herein.

7. The reduction process is performed based on a comparison of at least one of the following with a threshold value: the load current value or the related value, the amount of change in the load current value or the related value, and the ratio of the change in the load current value or the related value. The change in the determination criteria for the determination to facilitate the aforementioned reduction process includes an increase in the absolute value of the threshold. The electric vacuum cleaner according to any one of features 2 to 4.

8. The aforementioned increase process is performed based on a comparison between at least one of the following: the load current value or the related value, the amount of change in the load current value or the related value, and the ratio of the change in the load current value or the related value, and a threshold value. The change in the determination criteria for the determination to facilitate the aforementioned increase process includes reducing the absolute value of the threshold. The electric vacuum cleaner according to claim 1, 3, or 5, characterized by the features described herein.

9. The aforementioned increase process is performed based on the determination of an increase in the load current value or the related value, followed by a determination of a decrease, and then a determination of an increase again. The change in the determination criteria for the determination to facilitate the aforementioned increase process includes extending at least one of the following: the period between determining an increase in the load current value or the related value and determining a decrease; and the period between determining a decrease in the load current value or the related value and determining an increase again. The electric vacuum cleaner according to claim 1, 3, or 5, characterized by the features described herein.

10. The aforementioned increase process is performed based on a comparison between at least one of the following: the load current value or the related value, the amount of change in the load current value or the related value, and the ratio of the change in the load current value or the related value, and a threshold value. The change in the determination criteria for the determination to make the aforementioned increase process less likely to occur includes an increase in the absolute value of the threshold. The electric vacuum cleaner according to any one of features 2 to 4.

11. The aforementioned increase process is performed based on the determination of at least an increase in the load current value, followed by a determination of a decrease, and then a determination of an increase again. The change in the determination criteria for the determination to make the aforementioned increase process less likely to occur includes shortening at least one of the following: the period from determining an increase in the load current value or the related value to determining a decrease; and the period from determining a decrease in the load current value or the related value to determining an increase again. The electric vacuum cleaner according to any one of features 2 to 4.

Images