JP2004024491A - Charging type vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging type vacuum cleaner for reducing the load of a motor-driven blower and restraining waste of power of a power supply. <P>SOLUTION: This charging type vacuum cleaner 1 includes a control means 16 for varying the duty ratio of a driving current supplied to the motor-driven blower 4 for applying suction negative pressure to a dust collecting chamber 3. The control means 16 increases the duty ratio of a driving current according to a detected current value detected by a current detecting means 13 for detecting the driving current supplied to the motor-driven blower 4. The control means 16 reduces the value of the driving current supplied to the motor-driven blower 4 to a preset value I<SB>4</SB>when the driving current value is lowered below a threshold I<SB>2</SB>after the duty ratio reaches a designated value. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rechargeable vacuum cleaner using a rechargeable power supply such as a secondary battery as a power supply for an electric blower that applies an intake negative pressure to a dust collection chamber.
[0002]
[Prior art]
As a conventional rechargeable vacuum cleaner, there is known a rechargeable vacuum cleaner in which a duty ratio of a pulse-like drive current for driving an electric blower is controlled by a control circuit so that the drive current of the electric blower is controlled to a constant value. I have.
[0003]
This control circuit adjusts the duty ratio of the drive current to prevent the drive current from decreasing when the battery voltage starts to decrease or when the amount of air sucked into the dust collection chamber starts to decrease due to dust clogging in the dust collection chamber. For example, increase from 50%. As a result, until the duty ratio reaches a preset value of, for example, 100%, the drive current supplied to the electric blower is prevented from being reduced irrespective of the voltage drop of the battery, the clogging of the dust collection chamber, and the like. Performance degradation is prevented.
[0004]
[Problems to be solved by the invention]
However, after the duty ratio reaches the set value, if the dust collection chamber continues to be used in a state where the dust is collected, the suction air volume decreases with the suction of the dust, so that the dust suction force is further reduced. It cannot be cleaned. In this state, the load on the electric blower increases, and the power of the battery is wasted.
[0005]
Therefore, an object of the present invention is to provide a rechargeable vacuum cleaner capable of reducing the load on the electric blower and suppressing wasteful consumption of power supply power.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an electric blower for applying a suction negative pressure to a dust collection chamber, a chargeable power supply for supplying a drive current to the electric blower, and a current detection for detecting the drive current. Means for controlling the duty ratio of the drive current based on the detection current detected by the current detection means, and control means for controlling the drive current supplied to the electric blower to be constant. An electric vacuum cleaner, wherein the control unit is configured to control the drive current supplied to the electric blower when the current value detected by the current detection unit decreases below a threshold after the duty ratio reaches a predetermined value. Is reduced to a set value.
[0007]
Embodiment
Hereinafter, an embodiment of a vacuum cleaner according to the present invention will be described with reference to the drawings.
[First Embodiment]
A rechargeable vacuum cleaner 1 according to the present invention includes a cleaner body 2 as shown in FIG. In the cleaner main body 2, a dust collecting chamber 3, an electric blower 4 for applying a negative pressure to the dust collecting chamber 3, and a secondary battery (power supply) 5 for supplying electric power to the electric blower 4 are provided. I have. The electric blower 4 has a suction port 4a communicating with the dust collection chamber 3, a centrifugal fan 4b, and a DC motor 4c for driving the centrifugal fan 4b. A dust collection filter (not shown) is detachably mounted in the dust collection chamber 3.
[0008]
One end of a hose 6 is connected to a front portion of the cleaner main body 2, and the hose 6 and the dust collecting chamber 3 communicate with each other. An operation pipe 7 is connected to the other end of the hose 6, and the operation pipe 7 is provided with hand operation means 8. The hand operation means 8 is provided with an on / off hand operation switch SW1 for controlling the operation of the electric blower 4 via a control means to be described later, and strength switching hand switches SW2, SW3. An extension pipe 9 is connected to the operation pipe 7, and a suction port body 10 is connected to a tip of the extension pipe 9.
[0009]
Further, a control device 11 for the electric blower 4 is provided in the cleaner body 2 as shown in FIG. The control device 11 includes a drive circuit 12 that generates a rectangular pulse-shaped drive current for driving the electric blower 4 from the electric power of the battery 5, and a current detection circuit that detects the drive current supplied to the electric blower 4. It comprises a detection means 13 and an operation control circuit 15 which is operated by a constant voltage circuit 14 and comprises, for example, a CPU.
[0010]
The arithmetic control circuit 15 controls the drive circuit 12 based on the operation of each of the hand switches SW 1, SW 2, SW 3 provided in the hand operation means 8 and the detected current value from the current detection means 13. The duty ratio of the drive current supplied to the electric blower 4 from is controlled. Therefore, the arithmetic control circuit 15 and the drive circuit 12 together constitute control means 16 for the electric blower 4.
[0011]
Next, the operation of the rechargeable vacuum cleaner 1 will be described. When an ON signal is input to the arithmetic and control circuit 15 by the ON operation of the ON / OFF operation switch SW1, the drive circuit 12 starts the electric blower 4 with a predetermined duty so as to start the electric blower 4 with the power set by the strength switching hand switches SW1 and SW2. A drive current in the form of a rectangular pulse having a ratio is output, and the drive current is input to the electric blower 4. With this drive pulse current, the electric blower 4 is driven with a predetermined power according to the selected strength change hand operation switches SW2 and SW3. When the electric blower 4 is driven, the suction negative pressure of the suction port 4 a according to the power acts on the dust collection chamber 3, so that the suction of dust from the suction port body 10 into the dust collection chamber 3 is started.
[0012]
By starting the electric blower 4 by operating the switch, each step of the flowchart shown in FIG. 3 is disclosed.
[0013]
Step S1: When the drive pulse current starts to be supplied to the electric blower 4, the value of the drive pulse current is detected by the current detection means 13.
[0014]
Step S2: The arithmetic control circuit 15 determines whether or not sufficient power is held in the battery 5 based on the detected current value.
[0015]
If the battery 5 does not have enough power for the operation of the electric blower 4 and the remaining amount of the battery is low enough to charge the battery 5, the power is supplied from the battery 5 to the electric blower 4. The detected current value decreases sharply. When such a sharp decrease is detected in the detected current value, the process proceeds to step S7. On the other hand, when such a sharp decrease is not found in the detected current value, the electric blower 4 proceeds to step S3 so that the rechargeable vacuum cleaner 1 maintains the normal suction operation, and continues the operation. .
[0016]
Step S3: The continuation of the operation of the rechargeable vacuum cleaner 1 increases the amount of dust, that is, dust, that accumulates in the dust collection chamber 3, and the clogging of the filter of the dust collection chamber 3 proceeds. The negative pressure in 3 increases. When the rotation speed of the electric blower 4 increases with the increase of the negative pressure, the back electromotive force generated in the electric blower 4 increases. This back electromotive force causes a decrease in the drive current supplied from the drive circuit 12 to the electric blower 4. This decrease in the drive current causes the power of the electric blower 4 to decrease. Therefore, in step S3, when the detected current value from the current detecting means 13 decreases, the arithmetic control circuit 15 increases the duty ratio according to the amount of decrease in the drive current supplied from the drive circuit 12 to the electric blower 4. Let it. The feedback control of the control means 16 controls the drive current value to the electric blower 4 to be maintained at a predetermined value until the duty ratio reaches a preset maximum value (for example, 100%).
[0017]
Step S4: The arithmetic control circuit 15 determines whether or not the current duty ratio has reached the maximum value.
[0018]
The feedback control of steps S1 to S4 by the control means 16 is performed until the duty ratio reaches a preset maximum value.
[0019]
Step S5: When detecting that the duty ratio has reached the preset maximum value in step S4, the arithmetic and control circuit 15 determines whether or not the detected current value from the current detecting means 13 is equal to or less than the preset threshold value. . As the threshold current, a value that can drive the electric blower 4 with such power that the rechargeable vacuum cleaner 1 hardly absorbs dust is set.
[0020]
Steps S1 to S5 are repeated until the detected current value from the current detecting means 13 becomes equal to or less than the threshold value.
[0021]
Step S6: When the detected current value becomes equal to or less than the threshold value, the control means 16 sharply and greatly reduces the duty ratio of the drive current to the electric blower 4 to the set value. As a result, the drive current is not reduced to a natural gradual decrease due to the continuation of the operation state, but is actively reduced to, for example, a power that allows the electric blower 4 to maintain the operation.
[0022]
Step S7: After the drive current to the electric blower 4 is sharply reduced in step S6, the control means 16 determines whether or not the operation state in the power down has continued for a predetermined time, for example, three minutes. In addition, immediately after the start of the rechargeable vacuum cleaner 1, the control unit 16 detects a sharp decrease in the drive current value in step S2, and determines that the remaining battery level of the battery 5 has decreased due to this. Then, it is determined whether or not the operation state has passed a predetermined time.
[0023]
Step S8: The control means 16 sets the duty ratio of the drive current to the electric blower 4 to zero when the operation in the power-down due to the sudden decrease of the drive current in Step S6 has elapsed for a predetermined time, so that the electric blower 4 Stop the operation.
[0024]
Further, the control unit 16 determines in step S2 that the battery residual amount has decreased to such an extent that the battery 5 needs to be charged, and stops the operation of the electric blower 4 when the operation state has passed a predetermined time. .
[0025]
FIG. 4 is a graph showing the relationship between the amount of air drawn into the dust collection chamber 3 (Q) of the rechargeable vacuum cleaner 1 and the drive current (I) supplied to the electric blower 4. After the operation of the rechargeable vacuum cleaner 1 is started at the point a on the characteristic line 17 of this graph, the dust collected in the dust collection chamber 3 is maintained until the point b at which the duty ratio reaches the set maximum value. negative suction pressure of the suction port 4a with the increase in the amount decreases, but the suction air volume along with it decreases from Q ₁ to Q _2, the repetition of step S1~ step S4, the reduction of the drive current to the electric blower 4 depending since the duty ratio is increased, the value of the drive current is held at a predetermined value I _1. Therefore, in the region X from the point a~ point b, since the constant driving current I ₁ is controlled to be supplied to the electric blower 4, reduction in suction performance of the rechargeable vacuum cleaner 1 is prevented .
[0026]
However, if it is determined in step S4 that the duty ratio has reached the set maximum value, the duty ratio of the drive current to the electric blower 4 cannot be increased in the subsequent continuous operation, and this drive current is can not be increased, in the region Y between the point b of the point c, the suction air volume is reduced from Q ₂ to Q _3, a drive current with a decrease in the suction air amount decreases from I ₁ to I ₂ .
[0027]
As described in step S5, the value of the drive current supplied to the electric blower 4 is detected by the detection current from the current detection unit 13, and the suction air volume at which the rechargeable vacuum cleaner 1 can hardly absorb dust. becomes the threshold I ₂ indicated by point c corresponding to Q _3, as described in step S6, the driving current supplied to the electric blower 4 to the set value I ₄ indicated by a point d, is rapidly reduced yet greater , electric blower 4 the power-down can be achieved in the current value I ₄ ~I about ₅ to hold the operation. The power-down operation is performed in the area Z indicated by a point d~ point f, after the power-down operation in this region Z has continued for a predetermined time as described in step S7, the driving current I ₅ becomes zero, the electric The blower 4 is stopped as described in step S8.
[0028]
In the rechargeable vacuum cleaner 1 described in the first embodiment, the driving current is indicated by the point b in the operation state after the point b where the duty ratio of the driving current supplied to the electric blower 4 is set to the maximum value. and the decrease from the value I ₁ to the threshold I ₂ hardly exert suction force indicated by point c, a drive current flowing through the electric blower 4 is rapidly reduced significantly to a value I ₄ indicated by point d, then the drive current The supply is stopped.
[0029]
In the conventional rechargeable vacuum cleaner, the driving current supplied to the electric blower is not controlled in the driving state after the point b where the duty ratio is set to the maximum value. and suction air volume from the current value I ₁ at the point b is along the line b-e until the point e to reach the current value I ₃ to be zero, it has been left to natural decreasing due to the continuation of the operation state of the electric blower 4 . For this reason, in the conventional rechargeable vacuum cleaner, from the point c to the stop due to the operation of turning off the switch, a wasteful load is applied to the electric blower, and the battery is wasted in a state where no suction force is exerted.
[0030]
On the other hand, in the first embodiment of the present invention, as described above, the drive current supplied to the electric blower 4 is the value I _{2 of the} point c at which the rechargeable vacuum cleaner 1 can hardly exert suction power. at the time of the drop, because it rapidly decreases the set value I ₄ at point d, the power-down of the electric blower 4 in the region Z extending from point d to the stop of the electric blower 4, there is ensured a reduction in the load, Waste of the battery 5 is prevented.
[0031]
In addition, the electric blower 4 does not stop immediately at the time indicated by the point d, and receives a small amount of electric power in the power-down operation area Z from the time of the point d to the stop. The user of the rechargeable vacuum cleaner 1 feels a slight sign of the operation of the electric blower 4 during this time, so that the rechargeable vacuum cleaner 1 is not mechanically or electrically malfunctioning but has a trouble such as simple clogging. You can know what is happening.
[0032]
FIG. 5 is a graph showing the charge / discharge characteristics of the battery remaining amount (voltage) and charging time (time) of the battery 5 according to the present invention.
[0033]
Z ₁ point indicated by the voltage V ₁ and the charging time t ₁ in the characteristic line 18 of the battery 5 is driven to a value I ₄ shown by point d when the drive current supplied to the electric blower 4 has reached the point c of FIG. 4 9 shows the remaining battery charge of the battery 5 when the current is reduced and the reduced drive currents I _{4 to} I ₅ are continuously supplied during the time T. In contrast, Z ₂ point indicated by the voltage V ₂ and the charging time t _2, when it has reached the point c, as in the prior art without reducing the drive current to a value I ₄ indicated by point d, the line c between the drive current I ₂ ~I ₃ time T along the -e, indicating the residual amount of the battery of the battery 5 when continuously supplied.
[0034]
Both of these battery residual amounts Z ₁ and Z ₂ are set so as to be larger than the voltage V ₃ causing the reduction of the battery life and the battery residual amount at the point Z ₃ indicated by the charging time t ₃ . In the comparison between the remaining battery amounts Z ₁ and Z ₂ , the remaining battery amount Z ₁ according to the present application shows a larger value than the conventional remaining battery amount Z ₂ after the lapse of the time T. Therefore, it is possible to shorten the charging time of the battery 5, the time until Z ₃ that causes a reduction of the service life of the battery can be set longer as compared with the prior art, a reduction in the service life of the battery 5 Can be suppressed.
[0035]
<Embodiment 2>
In the first embodiment, the control unit 16 determines that the detection current value from the current detector 13 is the threshold value I ₂ or less that is set in advance (step S5), and the electric blower 4 immediately step S6 in order to power down The drive current value has been reduced.
[0036]
In contrast, in the second embodiment, as shown in FIG. 6, the detected current value from the current detector 13 is determined to be the threshold value I ₂ or less that is set in advance (step S5), and the control means 16 determines whether the drive current after reaching a threshold value I ₂ or less, the state of the threshold value or less is maintained for a predetermined time, for example 5 seconds to 10 seconds (step S51). Drive current and is continued below the threshold exceeds a predetermined time, as in the first embodiment in step S6, the value of the drive current is reduced to the set value I _4, by reduction of the driving current, The electric blower 4 is powered down, and in this power-down state, after the operation of the electric blower 4 is maintained for a predetermined time, the electric blower 4 is stopped.
[0037]
Thus, in step S51, by the state value of the drive current is the threshold value I ₂ below to determine whether a predetermined time has passed, for example, inlet of foreign matter accidentally suction port body 10, such as paper per sucking, even by reducing the drive current is temporarily threshold I ₂ or less for its, by removing the foreign matters, it is possible to return to a value exceeding the value before reducing the drive current or threshold I _2, Frequent erroneous operation due to such suction of foreign matter can be prevented, and usability can be improved.
[0038]
Further, in the first and second embodiments of the rechargeable vacuum cleaner according to the present invention, is supplied after the drop, the electric blower 4 than the threshold I ₂ detected current value from the current detector 13 is set in advance by greatly reducing the value of the drive current to the set value I _4, and the electric blower 4 through the operation state of the power down to stop it.
[0039]
On the other hand, without stopping the electric blower 4, the electric blower 4 can be in the power-down operation state as long as the power of the battery 5 continues.
[0040]
However, if the power-down operation is continued, a situation may occur in which a state in which the suction air volume (Q) into the dust collection chamber 3 is zero or close to this is maintained. In such a situation, if the electric blower 4 continues to receive the supply of the driving current, a rare short (layer short), which is a partial short circuit, may occur in the electric blower 4.
[0041]
Therefore, as shown in the first and second embodiments, in order to reliably prevent the short circuit, when the detected current value from the current detector 13 is lower than a preset threshold I _2, the predetermined time has passed It is desirable that the supply of the drive current to the electric blower 4 be stopped later. Further, the duration of the power-down operation before the stop is set under the worst possible situation, for example, under the highest environmental temperature where the voltage of the battery 5 is the highest and the highest possible environmental temperature is set. A time shorter than the time is employed.
[0042]
In the embodiment of the present invention, the rechargeable vacuum cleaner 1 includes an electric blower 4 for applying a suction negative pressure to the dust collection chamber 3 and a chargeable power supply (battery) for supplying a drive current to the electric blower 4. 5, a current detecting means 13 for detecting the driving current, and a driving current supplied to the electric blower 4 by controlling the duty ratio of the driving current based on the detected current detected by the current detecting means 13 ( control means (drive circuit _{1 2} for controlling such that I _1), and a calculation control circuit 15) 16. The control means 16, when the current value detected by the current detector 13 after the duty ratio reaches a predetermined value is lower than the threshold value I _2, sets the value of the driving current supplied to the electric blower 4 value I ₄ Greatly reduced to
[0043]
Therefore, according to the embodiment of the present invention, the driving current supplied to the electric blower 4 can be greatly reduced when the power of the rechargeable vacuum cleaner 1 for sucking dust is weakened. 4 can be reduced, and waste of the power supply 5 can be suppressed. In addition, by operating the electric blower 4 with the reduced drive currents I _{4 to} I ₅ , the user can sense that a trouble such as clogging has occurred.
[0044]
Further, in the embodiment of the present invention, the control means 16, when the detected current value has continued for a predetermined time or more the threshold I ₂ the following values, the value of the drive current supplied to the electric blower 4 to the set value I ₄ Greatly reduce. Detection current value without immediately reducing the drive current when it becomes a threshold value I ₂ following values after predetermined time or longer, than to reduce, for example, suction by the driving current of the paper to the suction port body 10 is temporarily Even if it is reduced, the normal suction state can be restored by removing the foreign matter, so that frequent malfunctions due to the suction of such foreign matter can be prevented, and the usability is improved.
[0045]
Further, in the embodiment of the present invention, the control means 16, when the value of the drive current supplied to the electric blower 4 continues for a predetermined time, significantly reduced until set value I _4, the driving of the electric blower 4 Stop supplying current. By stopping the supply of the drive current, the continuation of the operation of the electric blower 4 in a situation where the suction air volume Q becomes zero or almost zero is prevented, and the occurrence of a rare short circuit caused by the continuation of the operation in the situation is prevented. It can be reliably prevented.
[0046]
【The invention's effect】
As described above, according to the present invention, when the drive current value falls below a threshold after the duty ratio of the drive current supplied to the electric blower reaches a predetermined value, the drive current value , The load on the electric blower can be reduced, and the waste of power can be suppressed.
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a vacuum cleaner according to the present invention.
FIG. 2 is a block circuit diagram showing an electric circuit of a main body of the vacuum cleaner shown in FIG. 1;
FIG. 3 is a flowchart showing an operation of the vacuum cleaner according to the first embodiment of the present invention.
FIG. 4 is a graph showing a relationship between a suction air volume of a vacuum cleaner according to the present invention and a drive current supplied to the electric blower.
FIG. 5 is a graph showing charge / discharge characteristics of a battery according to the present invention.
FIG. 6 is a flowchart showing an operation of the second embodiment of the vacuum cleaner according to the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 rechargeable vacuum cleaner 3 dust collection chamber 4 electric blower 5 (power supply) battery 11 control device 12 drive circuit 13 current detection means 15 control circuit 16 (13, 15) control means

Claims (3)

An electric blower for applying a suction negative pressure to the dust collection chamber, a chargeable power supply for supplying a drive current to the electric blower, current detection means for detecting the drive current, and current detected by the current detection means Control means for controlling the drive current supplied to the electric blower to be constant by controlling the duty ratio of the drive current based on the detected current, the rechargeable vacuum cleaner comprising:
The control means reduces the value of the drive current supplied to the electric blower to a set value when the current value detected by the current detection means falls below a threshold after the duty ratio reaches a predetermined value. A rechargeable vacuum cleaner comprising: 2. The control device according to claim 1, wherein when the detected current value is equal to or less than a threshold value and continues for a predetermined time or more, a value of a drive current supplied to the electric blower is reduced to the set value. 3. Rechargeable vacuum cleaner. 2. The control device according to claim 1, wherein the control unit stops supplying the drive current to the electric blower when the drive current supplied to the electric blower has been reduced to the set value for a predetermined period of time. 3. Rechargeable vacuum cleaner.

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