JP2012120789A - Vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vacuum cleaner in which a reset time after overheat protection of an electric blower is shortened while the electric blower is surely protected against overheat.SOLUTION: The vacuum cleaner includes: a cleaner body; and an electric blower 36 housed in the cleaner body and including an electric motor 53 and a centrifugal fan 54 which is rotated by the electric motor 53 and exhaust to a first air course W1 for cooling the electric motor 53 and to a second air course W2 for cooling no electric motor 53. The vacuum cleaner has, in the second air course W2, a shunt resistor 46 that has a smaller heat capacity than the electric blower 36 and that is heated by a current flowing in the electric blower 36. In addition, the vacuum cleaner has a thermostat 42 that reduces the suction force of the electric blower 36 when the temperature of the shunt resistor 46 exceeds a preset temperature threshold.

Description

  Embodiment of this invention is related with the vacuum cleaner which interrupts | blocks the input of an electric blower, if the preset temperature threshold value is exceeded.

  Conventionally, in an electric vacuum cleaner, an electric blower is accommodated in a vacuum cleaner body provided with a dust collecting portion. The suction side of the electric blower communicates with the dust collection unit, and a hose body, an extension pipe, a floor brush, and the like are connected to the dust collection unit, for example. Then, due to the negative pressure generated by the driving of the electric blower, dust is sucked in from the floor brush, the extension pipe and the hose body together with the air through the dust collecting portion, and the dust is collected in the dust collecting portion. The electric blower is cooled by sucking the air in which dust is collected and passing the air through the air.

  In such a vacuum cleaner, for example, when the tip of a floor brush or the like is blocked or the amount of dust collected in the dust collecting part increases, and the amount of air sucked by the electric blower decreases, the air to the electric blower is reduced. Inflow decreases, cooling cannot catch up, and the temperature of the electric blower rises. Therefore, in order to protect the electric blower from overheating, when the temperature of the electric blower, for example, the ambient temperature (ambient temperature) on the exhaust side of the electric blower near the commutator reaches a predetermined temperature, the circuit is opened and the electric blower input is turned on. A thermostat to shut off is arranged.

JP 2006-136512 A Japanese Patent No. 3673945 JP-A-4-156811

  Since the electric blower has a relatively large heat capacity, it takes time until the ambient temperature rises, and it takes time to operate the thermostat, etc., or until the thermostat operates due to differences in the outside air temperature or exhaust contact There is a risk of variations in time and temperature. In addition, since the temperature of an electric blower having a relatively large heat capacity is unlikely to decrease, once the thermostat is activated, the time until the electric blower is cooled below a predetermined temperature, that is, the time until return is increased. In particular, when the outside air temperature is high, such as in summer, it may take a long time to return, for example, and the user must interrupt the cleaning operation during that time. In recent years, the electric blower may be covered with a cover body for noise reduction. In such a case, heat is likely to be trapped inside the cover body, and the time until return becomes longer.

  This invention is made | formed in view of such a point, and it aims at providing the vacuum cleaner which shortened the time to return after overheating protection, carrying out overheating protection of an electric blower reliably.

  The vacuum cleaner of the embodiment has a cleaner body. The vacuum cleaner also includes an electric part and a centrifugal fan that is rotated by the electric part and exhausts the first air path that cools the electric part and the second air path that does not cool the electric part. Electric blower housed in Further, the electric vacuum cleaner has a heat capacity smaller than that of the electric blower, and is disposed in the second air passage, and has a heating element that generates heat in accordance with the current flowing through the electric blower. And a vacuum cleaner has a detection control means to reduce the suction force of an electric blower at least when the temperature of a heat generating element exceeds the preset temperature threshold value.

It is a side view which notches and shows a part of the vacuum cleaner of 1st Embodiment. It is a circuit diagram which shows the internal structure of a vacuum cleaner same as the above. It is a perspective view which shows a vacuum cleaner same as the above. It is a circuit diagram which shows the internal structure of the vacuum cleaner of 2nd Embodiment. It is a graph which shows an example of the relationship between the temperature of the heat generating element of an electric vacuum cleaner same as the above, and the input of an electric blower.

  The configuration of the first embodiment will be described below with reference to the drawings.

  In FIG. 3, reference numeral 11 denotes a so-called canister-type vacuum cleaner, and the vacuum cleaner 11 has a pipe part 12 and a vacuum cleaner body 13 to which the pipe part 12 is detachably connected.

  The pipe part 12 is provided on the distal end side of the hose body 16, the connecting pipe part 15 connected to the cleaner body 13, the flexible hose body 16 communicating with the distal end side of the connecting pipe part 15. The hand operating section 17, the extension pipe 18 detachably connected to the distal end side of the hand operating section 17, and the floor brush 19 as a suction port body detachably connected to the distal end side of the extension pipe 18. It has.

  The hand operating part 17 has a gripping part 21 projecting toward the hose body 16, and the gripping part 21 is provided with a plurality of setting buttons 22 as setting means for driving operation, and stopping means for stopping the operation. A stop button 23 is provided.

  The vacuum cleaner main body 13 includes a hollow main body case 25. Inside the main body case 25, a dust collection chamber as a dust collection unit is defined on the front side, and the electric blower unit 32 is accommodated on the rear side. An electric blower chamber is defined. Further, a main body suction port 34 communicating with the dust collecting chamber is formed in the front portion of the main body case 25. The base end side of the connecting pipe portion 15 of the pipe portion 12 is connected to the main body suction port 34 in communication. The main body case 25 accommodates a secondary battery (battery pack) E (FIG. 2) as a battery which is a power supply unit that supplies power to the electric blower unit 32 and the like.

  Further, as shown in FIG. 1, the electric blower unit 32 includes an electric blower 36 and a detection unit 37 that is an air cooling unit attached to the electric blower 36. And although this electric blower part 32 is not illustrated, it is covered with a cover body, for example, and it is controlled that noises, such as a drive sound of electric blower 36, leak outside.

  Here, as shown in FIG. 2, in the vacuum cleaner 11, a control means 41 such as a microcomputer is electrically connected to the high voltage side of the secondary battery E, and in parallel with the control means 41. In addition, a series circuit of a thermostat 42 which is a detection control means as a temperature detection means and the electric blower 36 is electrically connected. Further, for example, a drain electrode of a p-type MOSFET 44 as a control element is electrically connected to the electric blower 36. In the MOSFET 44, a source electrode is grounded via a shunt resistor 46 as a heating element, and a gate electrode which is a control electrode is electrically connected to the control means 41. Therefore, a power supply circuit C to the electric blower 36 is configured by a series circuit of the secondary battery E, the thermostat 42, the electric blower 36, the MOSFET 44, and the shunt resistor 46. Further, the control means 41 includes a first voltage detection means 48 for detecting the output voltage of the secondary battery E, and an electric blower 36 by detecting a voltage value at a connection point between the shunt resistor 46 and the source electrode of the MOSFET 44. The second voltage detecting means 49 for detecting the value of the current flowing through the two is electrically connected to each other. That is, the shunt resistor 46 indirectly detects the amount of air generated by driving the electric blower 36 by detecting the current value flowing through the electric blower 36, and corresponds to the amount of current flowing through the electric blower 36 ( It generates heat in proportion. The control means 41 is electrically connected to a display means 51 such as a liquid crystal panel or a lamp, and a setting button 22 and a stop button 23.

  Then, the control means 41 controls the phase angle of the electric blower 36 by turning on and off the MOSFET 44 corresponding to the operation mode (position) set by the setting button 22, and the input of the electric blower 36 is set. Set to the rated input corresponding to the operation mode. Further, the control means 41 detects the discharge state of the secondary battery E based on the voltage value detected by the first voltage detection means 48 in the operation state in each operation mode, and also detects it by the second voltage detection means 49. The operating state of the electric blower 36, that is, the air volume generated by driving the electric blower 36 is detected by the voltage value, and the phase angle control of the electric blower 36 is performed based on these detections. Control. The operation mode of the electric blower 36 is relatively different from a plurality of operation modes having different rated inputs, for example, a weak mode which is a small input mode as a first mode having a relatively small rated input in the present embodiment. A plurality of operation modes are set in advance with a strong mode that is a large input mode as a second mode with a large rated input. In addition to these operation modes, there is a stop mode in which the operation of the electric blower 36 is stopped.

  Further, as shown in FIG. 1, the electric blower 36 is located between the electric motor 53 that is an electric part, the centrifugal fan 54 that is connected to the electric motor 53 and rotated, and the electric motor 53 and the centrifugal fan 54. A diffuser 55, which is a current plate, and a centrifugal fan 54 and a substantially cylindrical fan cover 56 that covers a part of the diffuser 55 are provided, and the phase angle is controlled by the control means 41 via the MOSFET 44. Hereinafter, for convenience, the centrifugal fan 54 side will be described as the front side, and the motor 53 side will be described as the rear side.

  The electric motor 53 includes a motor main body portion 61 that is a main body portion, and a frame 62 as a body case that holds the motor main body portion 61.

  The motor main body 61 includes, for example, a brush device 67 in which a rotor 66 is disposed inside a rectangular frame-shaped stator 65 and is electrically connected to the secondary battery E (FIG. 2). This is an inner rotor type that rotates by switching the rotating magnetic poles by sliding in contact with the integral commutator 68.

  The frame 62 includes a first frame 71 having a substantially bottomed cylindrical shape and a second frame 72 disposed along the radial direction at the front end portion of the first frame 71.

  The first frame 71 is formed of, for example, metal or synthetic resin, and holds the stator 65 therein. Further, on the rear end side of the first frame 71, brush attachment holes 73 to which the brush devices 67 are attached are formed at positions facing each other, and a plurality of brush attachment holes 73 are provided at positions between the brush attachment holes 73. The exhaust port 74 is formed with an opening.

  The second frame 72 is formed of, for example, metal or synthetic resin, and both ends are fixed to the front end side of the first frame 71 via screws 75 along the radial direction. The screw 75 also has a function of fixing the detection unit 37 to the electric blower 36. A fixing portion 76 for fixing the diffuser 55 is formed at the center of the second frame 72 so as to protrude forward.

  The centrifugal fan 54 is connected to the rotating shaft 66a of the rotor 66 and rotates integrally with the rotor 66, and is formed of a metal such as aluminum, for example. The centrifugal fan 54 is provided with a plurality of blades 79 in a spiral shape between a pair of front and rear fan plates 77 and 78 spaced apart from each other, and a suction port 80 is formed at the center of the front fan plate 77. Yes. Further, the front fan plate 77 is formed so as to protrude with a gradually reduced diameter from the peripheral edge portion to the suction port 80.

  The diffuser 55 rectifies a part of the air blown from the centrifugal fan 54 to the outer peripheral side and guides it to the electric motor 53 side, and is formed by a member such as a thermoplastic synthetic resin, for example. 53 and the centrifugal fan 54. Further, the diffuser 55 includes a plurality of upstream blades 83 projecting upward from the front surface, which is one main surface, and a plurality of downstream blades 84 projecting downward from the rear surface, which is the other main surface of the diffuser 55. It has one. The diffuser 55 is fixed to the second frame 72 via a screw 85 with a fixing portion 76 inserted in the center thereof.

  Further, the fan cover 56 is press-formed into a substantially cylindrical shape with a metal such as a galvanized steel plate, and is press-fitted to the outer peripheral edge of the first frame 71 of the frame 62 of the electric motor 53. The fan cover 56 is formed so as to be gradually reduced in diameter from the rear side to the front side, and has a round hole-shaped cover air intake 86 at the center of the front end. In addition, a slit-like exhaust opening 88 is formed on the outer periphery of the fan cover 56 so as to be spaced apart at a substantially equal angle in the circumferential direction. The rear end of the fan cover 56 is press-fitted and fixed to the outer edge of the first frame 71 of the frame 62.

  A seal member 91 is disposed between the suction port 80 of the centrifugal fan 54 and the rear portion of the cover intake port 86. Therefore, the cover intake port 86 is airtightly connected to the suction port 80, and the circulation flow of the air blown from the centrifugal fan 54 in the outer peripheral direction to the suction port 80 is blocked.

  The exhaust opening 88 is formed in a longitudinal shape along the circumferential direction of the fan cover 56, and guides part of the air blown out from the centrifugal fan 54 toward the outer circumferential direction to the outside of the fan cover 56.

  Therefore, in the electric blower 36, a part of the air blown from the centrifugal fan 54 to the outer peripheral side is rectified by the upstream blade 83 and the downstream blade 84 of the diffuser 55, and the frame 62 (first frame 71) of the electric motor 53 is obtained. The first air passage W1 that passes through the inside and cools the electric motor 53 (the motor main body 61) and is exhausted from the exhaust port 74, and the remaining part of the air blown from the centrifugal fan 54 to the outer peripheral side are A second air passage W2 is formed which is rectified by the upstream blade 83 of the diffuser 55 and exhausted from the exhaust opening 88 without cooling the electric motor 53 (motor body 61). That is, the air passing through the first air passage W1 includes the exhaust heat of the electric motor 53 of the electric blower 36, and the air passing through the second air passage W2 is not affected by the heat of the electric motor 53 of the electric blower 36. It is configured.

  On the other hand, the detection unit 37 is configured by covering a substrate 94 on which the shunt resistor 46 and the thermostat 42 are mounted adjacent to each other with a cover member 95, and is disposed in the second air passage W2.

  The cover member 95 is fixed to the side of the fan cover 56 of the electric blower 36 by the screw 75, and applies an external temperature (heat) such as an outside temperature to the shunt resistor 46 and the thermostat 42 accommodated therein. The shunt resistor 46 and the thermostat 42 are covered so as not to be affected by these temperatures (heat). The cover member 95 is formed with an opening 97 for introducing the air exhausted from the exhaust opening 88 into the opening at a position facing the exhaust opening 88 of the fan cover 56. A discharge port 98 for exhausting air introduced from the inside to the inside is formed.

  In the detection unit 37, the shunt resistor 46 is disposed so as to face the introduction port 97, and the thermostat 42 is disposed on the opposite side of the introduction port 97 with respect to the shunt resistor 46. Therefore, the shunt resistor 46 is configured such that air introduced from the introduction port 97 into the cover member 95 is blown and cooled by this air.

  Next, the operation of the first embodiment will be described.

  At the time of cleaning, the user attaches the dust collecting part to the cleaner body 13 and connects the connecting pipe part 15 of the pipe part 12 to the main body suction port 34. Note that this operation is not necessary when the dust collecting part and the connecting pipe part 15 are already attached.

  Next, when the user grips the grip portion 21 and operates the desired setting button 22, the MOSFET 44 is switched at the phase angle determined by the control means 41 according to the operated setting button 22, and the electric blower 36 is operated in the operation mode. In the present embodiment, it is driven with a predetermined rated input corresponding to the strong mode or the weak mode, and the negative pressure generated by the driving of the electric blower 36 is applied, so that dust on the surface to be cleaned together with air is a floor brush. Suction from the tip side of the tube part 12 such as 19.

  At this time, when the resistance value of the shunt resistor 46 is about 50 mΩ, for example, when a current of about 15 A flows, for example, the detection voltage at the second voltage detection unit 49 becomes 0.75V. At this time, the power consumed by the shunt resistor 46 is about 11.3 W (= 15 × 0.75), and the shunt resistor 46 generates heat corresponding to this power.

  The dust-containing air passes through the pipe portion 12 and is then sucked into the dust collecting portion from the main body suction port 34. After dust is separated and collected in the dust collecting portion, the dust-containing air is sucked into the electric blower 36.

  The air sucked into the electric blower 36 is sucked into the inside of the centrifugal fan 54 from the cover intake port 86 and the suction port 80, and from the center side to the outer peripheral side along the fan plates 77 and 78 of the centrifugal fan 54. Blown out.

  The air blown toward the outer peripheral side is blown toward the outer peripheral side of the diffuser 55 while being rectified along the upstream blade 83 of the diffuser 55.

  A part of the air blown out to the outer peripheral side of the diffuser 55 is rectified toward the center side of the diffuser 55 by the downstream blade 84 of the diffuser 55, and from within the first frame 71 from between the second frames 72 of the electric motor 53. After passing through the first frame 71 in the axial direction while cooling the motor main body 61, the exhaust port 74 enters the outside of the first frame 71 (electric motor 53), in this embodiment, the electric blower chamber. Is exhausted (first air passage W1). That is, the electric motor 53 (the motor main body 61) is cooled in accordance with the amount of air sucked by driving the electric blower 36.

  Further, the remaining part of the air blown out to the outer peripheral side of the diffuser 55 is blown out from the exhaust opening 88 to the outside of the fan cover 56 and flows into the inside of the cover member 95 from the introduction port 97 to cause shunt resistance. While cooling the unit 46, the air is exhausted from the discharge port 98 to the outside of the cover member 95, that is, the electric blower chamber in the present embodiment (second air passage W2). That is, the shunt resistor 46 is cooled in accordance with the amount of air sucked by driving the electric blower 36. In particular, since the first air passage W1 is an air passage for cooling the electric motor 53, exhaust heat from the electric motor 53 is included on the downstream side of the electric motor 53 of the first air passage W1, and the cooling efficiency is not good. On the other hand, since the shunt resistor 46 is disposed in the second air passage W2 where the electric motor 53 is not cooled, the shunt resistor 46 is effectively cooled.

  The air passing through the first air path W1 and the second air path W2 is exhausted from the electric blower chamber to the outside of the cleaner body 13 (main body case 25) through the exhaust hole.

  Here, for example, the electric blower 36 sucks in dust that accumulates in a predetermined amount or more in the dust collecting part, the inside air passage such as the pipe part 12 is clogged, or the suction port of the floor brush 19 is blocked. When the amount of air decreases relatively, the amount of air that cools the shunt resistor 46 also decreases relatively, so that the cooling cannot catch up with heat generation, and the temperature of the shunt resistor 46 gradually increases. To do. When the temperature of the shunt resistor 46 exceeds a predetermined temperature threshold set in advance, that is, the temperature at which the thermostat 42 opens, the thermostat 42 is opened by the temperature of the shunt resistor 46 to supply power to the electric blower 36. Only the electric blower 36 is forcibly stopped by opening the circuit C. At this time, the control means 41 can determine the stop of the electric blower 36 when the voltage detected by the second voltage detection means 49 becomes 0V. Then, the control means 41 that detects the stop of the electric blower 36 turns off the MOSFET 44 and displays on the display means 51 that the electric blower 36 has been stopped due to a decrease in the air volume.

  Further, when the electric blower 36 stops, no current flows through the shunt resistor 46, so the temperature of the shunt resistor 46 immediately decreases. When the temperature of the shunt resistor 46 becomes equal to or lower than the temperature threshold, the thermostat 42 is closed and the power supply circuit C to the electric blower 36 is formed again, so that the control means is operated by the operation of the setting button 22 by the user. It becomes possible for 41 to operate the electric blower 36 again.

  When the cleaning is completed, the user operates the stop button 23, so that the control means 41 sets the phase angle of the electric blower 36 to 0 and stops the electric blower 36.

  As described above, according to the first embodiment, the shunt resistor 46 for detecting the air volume of the electric blower 36 by current is used, and the temperature of the shunt resistor 46 exceeds a preset temperature threshold value. The suction force of the electric blower 36 is reduced at least, and in this embodiment, the current of the electric blower 36 is interrupted by the thermostat 42 and the electric blower 36 is stopped, so that a member that generates heat according to the current flowing through the electric blower 36 is separately provided. This is not necessary and the configuration can be further simplified.

  Moreover, when the temperature of the shunt resistor 46 exceeds a predetermined temperature threshold, the electric blower 36 is stopped by a mechanical configuration using the thermostat 42, for example, compared with a case where control is performed using a microcomputer or the like. Thus, reliability is further improved.

  In the first embodiment, the operation mode of the electric blower 36 set by the control means 41 may be one, or may be three or more with different rated inputs.

  Next, a second embodiment will be described with reference to FIGS. 4 and 5. In addition, about the structure and effect | action similar to the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, instead of the thermostat 42 of the first embodiment, as shown in FIG. 4, a temperature sensor 99 as temperature detecting means is provided, and a shunt resistor 46 detected by the temperature sensor 99 is provided. The control means 41 reduces the input of the electric blower 36 via the MOSFET 44 every time the temperature exceeds a predetermined plurality of temperature thresholds set in advance. That is, the temperature sensor 99 and the control means 41 constitute a detection control means 100.

  Here, a plurality of the temperature thresholds are set for each operation mode. For example, as shown in FIG. 5, when the operation mode of the electric blower 36 is the weak mode, the weak mode temperature thresholds T1L to T4L as the first to fourth first mode (small input mode) temperature thresholds are set. When the operation mode of the electric blower 36 is set to the strong mode, the strong mode temperature threshold values T1H to T4H are sequentially set as the first to fourth second mode (large input mode) temperature threshold values. . These temperature threshold values are not limited to four, but may be two, three, or five or more. Further, the number of temperature thresholds may be different for each operation mode.

  For example, when the control means 41 operates the electric blower 36 in the weak mode, if a predetermined amount or more of dust accumulates in the dust collecting part, or the internal air passage such as the pipe part 12 is clogged, the floor brush The air flow of the electric blower 36 decreases due to factors such as the 19 inlet being blocked, and the temperature of the shunt resistor 46 rises, and the temperature of the shunt resistor 46 detected by the temperature sensor 99 is the first weak mode. When the service temperature threshold T1L is exceeded, the control means 41 reduces the input of the electric blower 36. Thereafter, when the temperature of the shunt resistor 46 detected by the temperature sensor 99 further rises, the control means 41 reduces the input of the electric blower 36 every time the temperature threshold T2L, T3L for weak mode is exceeded, and the fourth When the temperature threshold T4L for weak mode is exceeded, the input of the electric blower 36 is reduced to 0 to stop the electric blower 36, and the display means 51 displays that the electric blower 36 has been stopped due to the decrease in the air volume.

  Similarly, for example, when the control means 41 operates the electric blower 36 in the strong mode, the air volume of the electric blower 36 decreases due to the above factors and the temperature of the shunt resistor 46 rises and is detected by the temperature sensor 99. When the temperature of the shunt resistor 46 exceeds the first strong mode temperature threshold value T1H, the control means 41 reduces the input of the electric blower 36. Thereafter, when the temperature of the shunt resistor 46 detected by the temperature sensor 99 further increases, the control means 41 decreases the input of the electric blower 36 every time the temperature exceeds the strong mode temperature threshold T2H, T3H, When the fourth strong mode temperature threshold value T4H is exceeded, the input of the electric blower 36 is lowered to 0 to stop the electric blower 36, and the display means 51 displays that the electric blower 36 has been stopped due to a decrease in the air volume. .

  During operation in each operation mode, in the state where the temperature of the shunt resistor 46 detected by the temperature sensor 99 does not exceed the temperature thresholds T4L and T4H, that is, the electric blower 36 is not stopped, for example, the pipe portion 12 The factors that reduce the air volume of the electric blower 36 are eliminated, such as when the dust clogged in the internal air passage is removed, or when the closed state of the suction port of the floor brush 19 is released, the air volume is secured, When the temperature of the shunt resistor 46 falls below each temperature threshold value, the control means 41 increases the input respectively.

  In addition, the temperature of the shunt resistor 46 detected by the temperature sensor 99 exceeds the maximum temperature threshold T4L, T4H in each operation mode, and the control means 41 temporarily stops the electric blower 36, and then the temperature sensor 99 detects the temperature. When the temperature of the shunt resistor 46 returns to at least the temperature threshold values T4L and T4H which are the largest in each operation mode, the control means 41 operates the electric blower 36 again by operating the setting button 22 by the user. Is possible.

  Thus, according to the second embodiment, the control means 41 constituting the detection control means 100 is electrically operated each time the temperature of the shunt resistor 46 exceeds a plurality of temperature threshold values set based on each of the operation modes. By sequentially reducing the input of the blower 36, the detection control means 100 does not unnecessarily stop the electric blower 36, and when the temperature of the shunt resistor 46 is lowered below each temperature threshold, The electric blower 36 (the electric vacuum cleaner 11) can be returned to the cleaning work earlier.

  And according to each embodiment described above, the heat capacity is smaller than that of the electric blower 36, and the shunt resistor 46, which is a heating element that generates heat in accordance with the current flowing through the electric blower 36, is not cooled by the electric motor 53. When the temperature of this shunt resistor 46 exceeds a preset temperature threshold, the suction force of the electric blower 46 is reduced at least when the temperature of the shunt resistor 46 exceeds a preset temperature threshold, and the heat capacity is smaller than that of the electric blower 36. Thus, the electric blower 36 can be effectively overheat protected, and even when the electric blower 36 is temporarily stopped by overheat protection, the temperature of the shunt resistor 46, in which no current flows due to this stop, immediately decreases. This is excellent in reliability and versatility. For example, the cleaning interruption time due to overheat protection can be shortened.

  In the second embodiment, the operation mode of the electric blower 36 set by the control means 41 may be three or more with different rated inputs.

  Further, in each of the above embodiments, the heating element is not limited to the shunt resistor 46, and generates heat according to the current flowing through the electric blower 36, such as a control element of the electric blower 36 such as the MOSFET 44, and the electric blower 36. Any element having a smaller heat capacity than the second air path W2 can be used.

  Further, the electric vacuum cleaner 11 is not limited to the canister type, and for example, an upright type in which a floor brush 19 is connected to the lower part of the vacuum cleaner body 13 or a handy type can be used.

  And although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11 Vacuum cleaner
13 Vacuum cleaner body
36 electric blower
42 Thermostat as detection control means
46 Shunt resistor as a heating element
53 Electric motors
54 Centrifugal fan
100 Detection control means
W1 First air passage
W2 Second air passage

Claims (3)

The vacuum cleaner body,
An electric blower that is provided in the vacuum cleaner main body and includes a motor-driven part and a centrifugal fan that is rotated by the motor-driven part to cool the motor-driven part and a second air path that does not cool the motor-driven part. When,
A heating element having a smaller heat capacity than this electric blower, disposed in the second air passage, and generating heat according to the current flowing through the electric blower,
A vacuum cleaner comprising: a detection control means for reducing at least the suction force of the electric blower when the temperature of the heating element exceeds a preset temperature threshold value. The vacuum cleaner according to claim 1, wherein the heat generating element is a shunt resistor for detecting an air volume of the electric blower by an electric current. The electric blower can be driven in multiple operation modes with different rated inputs,
The detection control means sequentially decreases the input of the electric blower each time the temperature of the heating element exceeds a plurality of temperature thresholds set based on each of the operation modes. Electric vacuum cleaner.

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