Vacuum cleaner

Abstract

To provide a vacuum cleaner that can appropriately prevent overheating of a motor while stabilizing control of the motor.SOLUTION: A vacuum cleaner comprises an electric air blower, a motor 12 for cleaning a part F to be cleaned, and control means for controlling the motor 12. The control means performs reduction processing of driving power of the motor 12 on the basis of a predetermined lock determination condition, and makes the reduction processing hardly occur in an early stage of start-up of the motor 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a vacuum cleaner that controls a motor for cleaning a part to be cleaned. [Background technology]

[0002] Conventionally, a suction port body with a so-called active brush structure, which includes a rotating cleaning body and a motor that rotates the rotating cleaning body, has been known as a cleaning tool used in an electric vacuum cleaner. In this type of suction port body, the rotating cleaning body rotated by the motor first picks up dust from the surface to be cleaned and then sucks it in, thereby efficiently removing dust from surfaces to be cleaned that tend to become entangled with dust, such as carpets.

[0003] When the rotating cleaning body is placed on a surface to be cleaned that has a large rotational resistance, such as a carpet with long pile, or when a cloth or the like is wrapped around the rotating cleaning body, the motor locks and a large current flows. Therefore, the motor current value is monitored, and when the current value exceeds a predetermined current threshold value for a predetermined time period, it is determined that the motor is locked and the motor is stopped. In such a configuration, a plurality of pairs of time threshold values ​​and current threshold values ​​for determination are provided, one pair being a pair with a long time threshold value and a small current threshold value, and the other pair being a pair with a short time threshold value and a large current threshold value, and the state of the suction port body, the rotating cleaning body, or the motor is detected based on these conditions, so that it is possible to determine whether or not a cleaning operation is performed on the surface to be cleaned, and whether or not the motor is locked under normal conditions. However, in a low-temperature environment such as winter or at the beginning of startup, the current value of the motor becomes relatively large, and the accuracy of determining whether or not the motor is locked based on the lock determination condition consisting of the pair of time threshold value and current threshold value may decrease. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-68680 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a vacuum cleaner that is capable of stabilizing control of a motor while appropriately preventing the motor from overheating. [Means for solving the problem]

[0006] The vacuum cleaner of the embodiment includes an electric blower, a motor for cleaning a part to be cleaned, and a control means for controlling the motor. The control means reduces the driving power of the motor based on a predetermined lock determination condition, and makes it difficult for the reduction process to occur in the early stage of starting the motor. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing a schematic view of a part of a vacuum cleaner according to an embodiment; [Diagram 2] FIG. 2 is a block diagram showing a part of the internal structure of the vacuum cleaner. [Diagram 3] FIG. [Figure 4] 4 is a table showing examples of lock determination conditions for the electric vacuum cleaner. [Diagram 5] Graph (a) shows an example of the average current value when the motor current flow time or current flow amount is small when the weight of the cleaning tool of the vacuum cleaner is applied, and graph (b) shows an example of the average current value when the motor current flow time or current flow amount is large when the weight of the cleaning tool of the vacuum cleaner is applied. [Figure 6] 6 is a flowchart showing an example of a process for making it difficult for a reduction process to occur in the control means of the vacuum cleaner; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, one embodiment will be described with reference to the drawings.

[0009] In FIG. 1, 1 denotes a cleaning tool. The cleaning tool 1 is also called a cleaning head or the like, and cleans a part to be cleaned F, which is a surface to be cleaned such as a floor. The cleaning tool 1 includes a case body 10. A dust collection port 100 is formed in the case body 10. A rotating cleaning body 11 is also rotatably arranged in the case body 10. The rotating cleaning body 11 is rotated by a motor 12 to scoop up dust on the part to be cleaned F to the dust collection port 100. In this embodiment, the rotating cleaning body 11 is attached to the dust collection port 100. The motor 12 is controlled by a control means 13 shown in FIG. 2.

[0010] As shown in FIG. 3, the cleaning tool 1 is used in a vacuum cleaner CL. In this embodiment, the cleaning tool 1 is applied to a suction-type vacuum cleaner CL that sucks dust together with air into a separation section 4 by negative pressure generated by driving an electric blower 3, which is a suction source arranged in a vacuum cleaner body 2 of the vacuum cleaner CL. The vacuum cleaner CL may be any type, such as a floor-traveling type or a canister type, a stick type, an upright type, a handy type, or a self-propelled vacuum cleaner. In this embodiment, the vacuum cleaner CL will be described by taking a stick-type vacuum cleaner as an example. In the illustrated example, the cleaning tool 1 is also called a suction port body or a floor brush, and is mechanically and fluidically connected to the vacuum cleaner body 2 indirectly via an extension tube 5, which is a tube part, or directly by a connection tube 14, which is a connection part connected to a case body 10. Furthermore, in this embodiment, the operation or suction power of the electric blower 3, or the operating strength such as strong mode or weak mode, i.e., the operating mode, and the on / off of the rotation of the rotating cleaning body 11 or the motor 12 are set by the user by operating the switch 7 on the hand-held operation unit 6, which is a gripping unit for gripping operation. The vacuum cleaner body 2 is provided with a main body control unit 8 that operates the electric blower 3 according to the operation set by the switch 7. The switch 7 or the main body control unit 8 is electrically connected to the control means 13 (shown in FIG. 2). The control means 13 (shown in FIG. 2) may be provided in the cleaning tool 1, but in this embodiment, at least a part of the control means 13 (shown in FIG. 2) is incorporated in the main body control unit 8. The power supply unit B of the electric vacuum cleaner CL is provided in the vacuum cleaner body 2, for example. In this embodiment, the power supply unit B is a battery or a secondary battery, but is not limited thereto, and may be an AC-DC adapter that draws power from an external power source such as a commercial power source, a cord reel device, or the like.

[0011] Next, the internal structure of the control means 13 will be described with reference to FIGS.

[0012] The control means 13 has a power variable section 130 that varies the drive power of the motor 12. The power variable section 130 may vary the drive power of the motor 12 steplessly, or may vary it in one of a plurality of steps. In this embodiment, the power variable section 130 is capable of setting the drive power of the motor 12 in at least one of a plurality of steps.

[0013] As a method of varying the driving power of the motor 12 by the power variable unit 130, for example, the power supply time or the amount of power supplied from the power source to the motor 12 is adjusted, and the driving power of the motor 12 is set according to the power supply time of the motor 12. As an example, the power variable unit 130 sets the driving power of the motor 12 by using a PWM signal as a control signal to the motor 12, i.e., an applied voltage, and adjusts the duty ratio of the PWM signal. In other words, when the duty ratio of the PWM signal is set to 100%, the driving power of the motor 12 is maximized, and by lowering the duty ratio of the PWM signal, the driving power of the motor 12 is reduced, and the rotation speed and rotation torque of the rotating cleaning body 11 are reduced. In other words, when the power variable unit 130 increases the driving power of the motor 12, it increases the duty ratio, and when it decreases the driving power of the motor 12, it decreases the duty ratio. In this embodiment, the power variable unit 130 has a plurality of different duty ratios, and by selectively setting the duty ratio of the PWM signal of the motor 12 to one of these duty ratios, it is possible to set the drive power of the motor 12 to a plurality of different drive powers.

[0014] The setting of the driving power of the motor 12 by the power variable unit 130 may be switched according to the user's setting by the switch 7 (shown in FIG. 3) or the like, or may be switched according to the strength or weakness of the suction power or the operation mode of the electric blower 3, or may be automatically switched according to the cleaning situation. The cleaning situation refers to, for example, the type of floor constituting the part to be cleaned F, or the amount of dust suctioned in the part to be cleaned F, etc. That is, the power variable unit 130 may automatically select and set the driving power of the motor 12 in combination with a cleaning situation detection means such as a type detection means for detecting the type of the part to be cleaned F and / or a dust amount detection means for detecting the amount of dust suctioned. The type detection means and the dust amount detection means may be of any known configuration. In this embodiment, for example, the power variable unit 130 selectively uses either a PWM signal with a duty ratio of 100% or a PWM signal with a duty ratio of 40% to set the driving power of the motor 12 to either strong or weak.

[0015] The control means 13 also has a current detection unit 131 that detects the current value of the motor 12. The current detection unit 131 detects the current value of the motor 12 at every predetermined detection period. As an example of a method for detecting the current value of the motor 12 by the current detection unit 131, a current is passed through a resistor having a small resistance value, which is a detection element, that is, a so-called shunt resistor, and the potential difference generated at both ends of 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 taken in. In this embodiment, the current value detected by the current detection unit 131 is, for example, a load current value. The load current value is a current value indicating 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, an average value of current values ​​acquired a predetermined number of times at every predetermined time. This actual current value is largely dependent on the duty ratio of the PWM signal of the power variable unit 130. Therefore, in this embodiment, the load current value is calculated by dividing the actual current value by the duty ratio of the PWM signal in the power variable unit 130 to make the load current value independent of the duty ratio of the PWM signal. That is, (load current value)=(actual current value) / (duty ratio). Therefore, the load current value in this embodiment is a value calculated based on the value of the current flowing through the motor 12 and the duty ratio.

[0016] In control and judgment by the control means 13, a related value may be used instead of or in addition to the current value detected by the current detection unit 131. The related value of the current value includes a value that is calculated from the current value flowing through the motor 12 and has a correlation with this current value, such as the current value itself flowing through the motor 12 and a value obtained by subtracting a predetermined value from the current value flowing through the motor 12. Hereinafter, the "current value of the motor 12 or a related value thereof" will be simply referred to as the "current value of the motor 12", and the "rotational load of the rotating cleaning body 11 or the motor 12" will be simply referred to as the "rotational load".

[0017] 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, and the like and acquires the value of a current flowing through the motor 12, an actual current value calculation unit that calculates an actual current value, and a load current value calculation unit that calculates a load current value, but the current value acquisition unit, actual current value calculation unit, and load current value calculation unit may each be configured as separate circuit units, or may be configured in any combination, or some of them may form part of other circuit units. In other words, the current detection unit 131 is not limited to being equipped integrally with the current value acquisition unit, actual current value calculation unit, and load current value calculation unit.

[0018] Furthermore, the control means 13 has a storage unit 132 such as a memory. In this embodiment, the storage unit 132 stores the current value detected by the current detection unit 131, various judgment thresholds, judgment values, etc. The storage unit 132 also stores various data used for control by the control means 13, such as other arbitrary thresholds, flags, programs, etc.

[0019] The control means 13 also has a determination unit 133. The determination unit 133 determines the state of the motor 12 or the rotating cleaning body 11 based on the current value detected by the current detection unit 131, and controls the setting of the drive power of the motor 12 by the power variable unit 130 in accordance with the determination. In this embodiment, the determination unit 133 determines whether the rotating cleaning body 11 and the motor 12 are locked, that is, whether the rotation of the motor 12 has been forcibly stopped due to an external factor such as entanglement of a cloth or the like, even though the motor 12 is energized, based on a preset lock determination condition. The details of this determination will be described later.

[0020] The power source for the motor 12 and the control means 13 may be provided in the cleaning tool 1 or may be taken from a power source section B of the cleaner body 2 (shown in FIG. 3).

[0021] Next, the operation of one embodiment will be described.

[0022] When cleaning, the user holds the handheld control unit 6 and operates the switch 7, causing the main body control unit 8 to operate the electric blower 3. The negative pressure generated by the operation of the electric blower 3 acts on the extension tube 5 and the cleaning tool 1 via the separation unit 4, so that dust on the area to be cleaned is sucked into the separation unit 4 together with air from the dust collection port 100.

[0023] Furthermore, the control means 13 activates the motor 12 of the cleaning tool 1 by the power variable unit 130 to rotate the rotary cleaning body 11. The rotation of the rotary cleaning body 11 stirs up dust on the area to be cleaned F, and the stirred-up dust is sucked into the separation unit 4 by the negative pressure acting on the dust collection port 100. At this time, the control means 13 operates the motor 12 using a PWM signal corresponding to, for example, the operation mode of the electric blower 3 or the driving force set by the user. Note that the user can operate the switch 7 to stop the rotation of the rotary cleaning body 11 of the cleaning tool 1 as necessary, for example, to prevent an object from being caught in the rotary cleaning body 11.

[0024] The user places the cleaning tool 1 on the part to be cleaned F and alternately moves it back and forth using the operating unit 6, thereby successively sucking dust on the part to be cleaned F into the separation unit 4. The dust is separated and collected from the dust-containing air sucked into the separation unit 4. The air from which the dust has been separated cools the electric blower 3 and is then discharged outside the vacuum cleaner body 2.

[0025] During operation of the motor 12, the control means 13 judges whether the rotating cleaning body 11 and the motor 12 are locked in the judgment section 133 based on a comparison between a predetermined current value of the motor 12 detected by the current detection section 131 and a threshold current value in the lock judgment condition, and a comparison between the duration of the current value and a time threshold.

[0026] In this embodiment, the "predetermined current value of the motor 12" refers to a current value within a predetermined short time from the time of determination, i.e., the most recent current value, and is preferably used, but is not limited to this, and may be the current value immediately prior to the latest current value, i.e., the most recent current value stored in the storage unit 132, i.e., the current value one detection cycle before the current value of the motor 12 by the current detection unit 131 from the time of determination. The immediately prior current value refers to the most recent current value stored in the storage unit 132 that is closest to the predetermined current value, i.e., the current value one detection cycle before the predetermined current value, but is not limited to this, and may be a past current value within a sufficiently short predetermined time, such as two or three detection cycles before the predetermined current value, or a value calculated from multiple immediately prior current values, such as the average current value within a predetermined time from the predetermined current value.

[0027] When the determination unit 133 determines that a predetermined lock determination condition is satisfied while the motor 12 is in operation, the control means 13 reduces the drive power of the motor 12 by the power variable unit 130, and essentially stops the motor 12. Hereinafter, this control will be referred to as reduction processing or power reduction control.

[0028] The reduction process is a control aimed at preventing overheating of the motor 12 due to a continued locked state by stopping the motor 12. The lock determination condition for performing the reduction process may be set arbitrarily, but in this embodiment, at least a combination of a threshold value of the current value of the motor 12 and a time threshold value is included as a condition. The reduction process is performed based on the fact that a state in which the current value of the motor 12 is equal to or greater than the threshold value has continued for equal to or greater than the time threshold value.

[0029] Here, the motor 12 tends to consume more current relative to the load when in a low-temperature environment, and consumes less current relative to the load when in a high-temperature environment. A low-temperature environment refers to a situation in which the internal temperature of the motor 12 drops below a predetermined temperature at start-up, such as when used in winter or in cold regions, and a high-temperature environment refers to the opposite environment, or an environment that is not a low-temperature environment, i.e., a non-low-temperature environment.

[0030] Therefore, when there is only one locking condition, if the threshold current value in the locking condition is set relatively high so that the reduction process does not occur when, for example, a long-pile carpet is cleaned in a low-temperature environment, that is, in a cleaning environment where the current value of the motor 12 tends to be large, the current value of the motor 12 when the rotating cleaning body 11 and the motor 12 are locked in a high-temperature environment will be lower than the threshold current value in the locking condition, and the reduction process may not occur even in a necessary situation. Conversely, if the threshold current value in the locking condition is set relatively low so that the reduction process occurs when, for example, the rotating cleaning body 11 and the motor 12 are locked in a high-temperature environment, the current value of the motor 12 will frequently exceed the threshold current value in the locking condition when a long-pile carpet is cleaned in a low-temperature environment, and the driving power of the motor 12 will be unnecessarily reduced, which may cause inconvenience to the user.

[0031] Therefore, in this embodiment, a plurality of types of lock determination conditions are set in advance. The plurality of lock determination conditions are set such that the larger the current threshold is, the smaller the time threshold is. In other words, when any two of the plurality of lock determination conditions are compared, the magnitude relationship of the current threshold and the magnitude relationship of the time threshold are reversed. In other words, the current threshold of one lock determination condition is set smaller than the current threshold of the other lock determination condition, and the time threshold of the other lock determination condition is set larger than the time threshold of the one lock determination condition.

[0032] An example of the lock determination condition of this embodiment is shown in FIG. 4. In this embodiment, three types of lock determination conditions are preset. Lock determination condition 1 is, for example, a high current / short time condition with a current threshold of 3A and a time threshold of 0.8 seconds. Lock determination condition 2 is, for example, a low current / long time condition with a current threshold of 2.25A and a time threshold of 1.6 seconds. Lock determination condition 3 is, for example, an ultra-low current / ultra-long time condition with a current threshold of 1.5A and a time threshold of 16 seconds.

[0033] In the lock determination condition 2, the time threshold value of 1.6 seconds takes into consideration the time it takes for a user to make one back and forth movement of the cleaning tool 1. That is, the moving speed of the cleaning tool 1 by a typical user is 0.5 m / second as specified in a given standard such as JIS, and the time it takes a typical user to move the cleaning tool 1 from starting to move forward until it stops is about 0.8 to 1 second, and the time it takes for a typical user to move the cleaning tool 1 from starting to move backward until it stops or moves forward again is about 1 to 1.5 seconds, so 1.6 seconds is set as the time it takes for the cleaning tool 1 to make one movement.

[0034] When the cleaning tool 1 is pulled backward, a force acts in a direction lifting the cleaning tool 1 from the part to be cleaned F, so the load on the rotating cleaning body 11 is significantly reduced and the current value is reduced. Therefore, if the reduced current value is less than 2.25 A or less than 1.5 A, lock determination conditions 2 and 3 are not met, and so if the cleaning tool 1 is moved back and forth, only lock determination condition 1 is valid.

[0035] On the other hand, when the rotating cleaning body 11 and motor 12 are locked, the current value of the motor 12 is relatively constant, so that lock determination conditions 2 and 3 are also valid, and even if the current value is low when the rotating cleaning body 11 and motor 12 are locked, a lock determination is made, i.e., a determination that the rotating cleaning body 11 and motor 12 are locked.

[0036] In this way, by setting multiple lock determination conditions each having a combination of a current threshold value and a time threshold value as conditions, and reversing the magnitude relationship between the current threshold value and the time threshold value in these lock determination conditions, it is possible to distinguish between a case where a long-pile carpet is being cleaned in a low-temperature environment and a case where the rotating cleaning body 11 and motor 12 have locked in a high-temperature environment, and to perform a reduction process when necessary.

[0037] However, for example, in a low-temperature environment, when the cleaning tool 1 is stationary on a carpet with long pile, it is considered that the current value of the motor 12 will remain relatively high for a long time. In particular, immediately after the start of cleaning, the cleaning tool 1 is often stationary on the cleaned part F, so there is a concern that the lock determination condition will be met soon after starting, and a reduction process will occur. In addition, when the control means 13 reduces the driving power of the motor 12 by some control, the rotation torque of the rotating cleaning body 11 is small, so that the rotation resistance due to the carpet or the like becomes a relatively large load, and the difference in current value between on the carpet and when locked becomes smaller than usual. Taking into account the relative increase in the current value of the motor 12 in a low-temperature environment and the relative decrease in the current value of the motor 12 in a high-temperature environment, a reverse state in which the current value of the motor 12 when cleaning a carpet in a low-temperature environment is larger than the current value when the rotating cleaning body 11 and the motor 12 are locked in a high-temperature environment is likely to occur.

[0038] Therefore, in this embodiment, in the early stage of starting the motor 12, the decrease process is made less likely to occur.

[0039] The initial start-up of the motor 12 refers to, for example, a period in which the accumulated drive time from the start of the start of the motor 12 or a related value thereof is within a predetermined threshold value, which is a judgment threshold value. If the accumulated drive time from the start of the motor 12 or a related value thereof is less than the predetermined judgment threshold value, the state in which the decrease process is unlikely to occur is set, and the state in which the decrease process is unlikely to occur is cancelled and restored to the original state, with at least one condition being that the accumulated drive time from the start of the motor 12 or a related value thereof becomes equal to or greater than the predetermined judgment threshold value.

[0040] For example, the judgment threshold is set to the time until the internal temperature of the motor 12 is expected to exceed a predetermined temperature. It has been experimentally found that the internal temperature of the motor 12 gradually rises due to its own heat generation when it is continuously driven, and that as the internal temperature rises, the low temperature state is overcome and large fluctuations in the current value are suppressed within a relatively short period of time. Therefore, in this embodiment, the judgment threshold is set to the time until the low temperature state is overcome, for example, one minute.

[0041] In addition, the longer the current supply time or the amount of current supply to the motor 12, the larger the current value flowing through the motor 12, so the motor 12 generates more heat and the time required to recover from the low temperature state tends to be shorter. When the current supply time or amount of current supply to the motor 12 is small, for example, when the duty ratio of the PWM signal is 40%, as shown in Fig. 5(a), the fluctuation in the current value of the motor 12 settles down more quickly when the current supply time or amount of current supply to the motor 12 is large, for example, when the duty ratio of the PWM signal is 100%, as shown in Fig. 5(b). Therefore, preferably, the cumulative degree of the accumulated drive time or its related value or the judgment threshold is changed according to the current supply time or amount of current supply to the motor 12, for example, the duty ratio of the PWM signal, and the greater the current supply time or amount of current supply, the greater the cumulative degree of the accumulated drive time or its related value is changed, or the judgment threshold is changed to a shorter value.

[0042] There are various possible methods for "making the decrease process less likely to occur." For example, there are possible methods such as adding an additional condition to the lock determination condition by the determination unit 133, correcting the current value detected by the current detection unit 131, and ignoring the lock determination. In this embodiment, the determination unit 133 changes or tightens the lock determination condition so that the lock determination is less likely to occur.

[0043] There are various methods for changing or tightening the locking determination conditions. For example, 1) one or more of the locking determination conditions set in advance, starting from the one with the lowest current threshold, are invalidated, 2) the current threshold and / or time threshold of the locking determination conditions used at the beginning of the start-up are set to values ​​different from those of the locking determination conditions used at other times, and 3) the current threshold and / or time threshold of the locking determination conditions used at the beginning of the start-up are calculated based on some predefined value. In particular, taking into consideration that the current value of the motor 12 is relatively large at the beginning of the start-up of the motor 12, it is preferable to tighten the threshold condition of the current value or a value related thereto in the locking determination conditions. In this embodiment, the above 1) is used, and in the example shown in FIG. 4, at least the "locking determination condition 3" with the lowest current threshold is invalidated.

[0044] This control will be described with reference to the flowchart shown in FIG.

[0045] When the vacuum cleaner CL starts up, in step S1, control means 13 sets flag isCold, which indicates whether or not it is the early stage of start-up or not, that is, whether or not it is a low temperature environment, to True, and sets timer tCold, which indicates the accumulated driving time of motor 12 since start-up, to 0. In control means 13, determination unit 133 tightens the lock determination condition so that the decrease process is less likely to occur while flag isCold is True.

[0046] Next, in step S2, the control means 13 judges whether the motor 12 is driving or not based on, for example, a current value detected by the current detection unit 131. If it is judged that the motor 12 is not driving, that is, if the answer is NO in step S2, step S2 is repeated. If it is judged in step S2 that the motor 12 is driving, that is, if the answer is YES in step S2, in step S3, the control means 13 judges whether the current supply time or current supply amount of the motor 12, which in this embodiment is the duty ratio of the PWM signal, is equal to or greater than a predetermined threshold value D_Heat. The threshold value D_Heat is a duty ratio at which the motor 12 is assumed to generate heat quickly, and is set to, for example, 50% in this embodiment.

[0047] In step S3, when it is determined that the duty ratio is equal to or greater than D_Heat, that is, when the result of step S3 is YES, in step S4, the control means 13 adds the accumulation degree C_Hi to the timer tCold, and proceeds to step S5. The accumulation degree C_Hi is the amount of the timer tCold to be added when the duty ratio is relatively large, and is set to, for example, 2 in this embodiment.

[0048] Also, in step S3, if it is determined that the duty ratio is not equal to or greater than D_Heat, that is, if NO in step S3, the control means 13 adds 1 to the timer tCold in step S6, and the process proceeds to step S5.

[0049] Therefore, in this embodiment, by the processes of steps S3, S4, and S6, when the duty ratio of the PWM signal for driving the motor 12 is 50% or more, the accumulation degree is doubled compared to when the duty ratio of the PWM signal for driving the motor 12 is less than 50%. Note that in this embodiment, an example is shown in which the loop period of the control of steps S2 to S6 is set to, for example, the detection period of the current value of the motor 12 by the current detection unit 131, for example, 100 ms. Therefore, when the duty ratio of the PWM signal for driving the motor 12 is less than 50%, the accumulation degree is 100 ms, and when the duty ratio of the PWM signal for driving the motor 12 is 50% or more, the accumulation degree is 200 ms.

[0050] Then, in step S5, the control means 13 judges whether the timer tCold is equal to or greater than the judgment threshold T_Heat. The judgment threshold T_Heat is, for example, 600. That is, in this embodiment, the judgment threshold T_Heat corresponds to 6000 ms, or 1 minute. In step S5, if it is judged that the timer tCold is not equal to or greater than the judgment threshold T_Heat, that is, if the answer is NO in step S5, the process proceeds to step S2. In addition, in step S5, if it is judged that the timer tCold is equal to or greater than the judgment threshold T_Heat, that is, if the answer is YES in step S5, in step S7, the control means 13 sets the flag isCold to False, that is, it judges that the motor 12 is no longer in the initial start-up stage or has left the low temperature environment, and ends the process.

[0051] Thus, according to this embodiment, the control means 13 reduces the driving power of the motor 12 based on a predetermined lock determination condition, and by making the reduction process less likely to occur in the early stages of startup of the motor 12, it is possible to prevent the reduction process from occurring frequently based on the lock determination condition due to an increase in the current value of the motor 12 in a low temperature environment in the early stages of startup.

[0052] Therefore, even when starting up in a situation where the current value of motor 12 is large due to low temperatures, such as when used in winter or cold regions, the control means 13 can accurately and appropriately perform the reduction process of motor 12, so that the driving power of motor 12 is not unnecessarily reduced, and the control of motor 12 is stabilized while the reduction process is performed when necessary, making it possible to appropriately prevent overheating of motor 12 due to excessive current caused by locking.

[0053] For example, by setting multiple lock determination conditions each having as its condition a combination of a threshold value of the motor 12 current value or a related value and a time threshold value, and disabling one or more lock determination conditions in the order of the smallest threshold value of the motor 12 current value or a related value to make it difficult for the reduction process to occur, it is possible to easily prevent the reduction process from occurring based on the lock determination conditions caused by an increase in the current value of the motor 12 in a low temperature environment at the beginning of startup.

[0054] In addition, in a low-temperature environment at the beginning of startup of the motor 12, one or more lock determination conditions are invalidated in ascending order of the threshold of the current value or a value related thereto of the motor 12, so that it is possible to set a lock determination condition in which, for example, the threshold of the current value or a value related thereto and / or the time threshold are more extreme. For example, even if a lock determination condition in which the threshold of the current value or a value related thereto is extremely small and the time threshold is extremely long is set as in lock determination condition 3 in the example shown in FIG. 4, it is basically invalidated at the beginning of startup of the motor 12, and it is possible to prevent unnecessary lock determination from occurring due to this lock determination condition. Therefore, when the motor 12 has passed the beginning of startup and is no longer in the low-temperature environment, it is possible to appropriately determine that the motor 12 is locked by further using a lock determination condition in which the threshold of the current value or a value related thereto and / or the time threshold are more extreme.

[0055] Furthermore, by canceling the process that makes it difficult for a lock determination to occur when at least one of the conditions is that the accumulated driving time of the motor 12 since the start of the motor 12 or a related value thereof has reached or exceeded a predetermined judgment threshold, it is possible to prevent a state in which the reduction process or the lock determination is difficult to occur from continuing even though the motor 12 has left the low temperature environment and the current value has stabilized.

[0056] In addition, by changing the accumulated drive time or the accumulated degree of its related value or the judgment threshold value according to the current supply time or current amount of the motor 12, which in this embodiment is based on the duty ratio of the PWM signal, it is possible to appropriately set the period during which the reduction process or lock judgment is unlikely to occur, taking into account the influence of heat generation due to the current supply to the motor 12.

[0057] Although some embodiments of the present invention have been described, these embodiments are presented as examples, and it is not intended that the scope of the invention be limited to these embodiments. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0058] CL Vacuum Cleaner F Area to be cleaned 3 Electric blower 12 Motor 13 Control Means

Claims

1. An electric blower; A motor for cleaning the part to be cleaned; A control means for controlling the motor, The control means reduces the drive power of the motor based on a predetermined lock determination condition, and makes the reduction process less likely to occur in the early stage of starting the motor. A vacuum cleaner characterized by:

2. The process of making the reduction process less likely to occur is cancelled on the condition that the accumulated drive time of the motor from the start of the motor or a value related thereto is equal to or greater than a predetermined threshold.

2. The vacuum cleaner according to claim 1.

3. The degree of accumulation of the accumulated driving time or the related value or the threshold value is changed according to the current supply time or current supply amount of the motor.

3. The vacuum cleaner according to claim 2.

4. a plurality of lock determination conditions are set, each of which has at least a combination of a threshold value of a current value or a value related thereto of the motor and a time threshold value as a condition; The decrease process is made less likely to occur by invalidating one or more of the lock determination conditions in ascending order of the threshold value of the motor current value or the related value.

4. The vacuum cleaner according to claim 1, wherein the vacuum cleaner comprises a first insulating layer.

Images