Technical Field

[1] An aspect of the present invention relates to a vacuum cleaner, and more particularly, to a vacuum cleaner which generates different sound according to the amount of dust particles contained in air when a dust-laden air is drawn into the vacuum cleaner so that a user can recognize a cleaning state of a current place or whether or not the cleaning operation is completed. Background Art

[2] Generally, vacuum cleaners may be classified into an upright type vacuum cleaner and a canister type vacuum cleaner. The upright type vacuum cleaner is formed so that a nozzle assembly is directly connected to a cleaner body without requiring a separate hose or an extension pipe, and uses the gravity of the cleaner when cleaning a carpet. Therefore, cleaning efficiency may be enhanced. Alternatively, the canister type vacuum cleaner has a hose or an extension pipe to connect a nozzle assembly to a cleaner body so that the canister type vacuum cleaner can manipulate the nozzle assembly freer than the upright type vacuum cleaner. Therefore, the canister type vacuum cleaner is effective in cleaning a floor or a narrow place such as steps.

[3] Conventional vacuum cleaner includes a sound generator which generates sound to make a user recognize a state of a vacuum cleaner or whether or not a vacuum cleaner is operating.

[4] For example, the Korean Patent No. 575705 discloses a robot cleaner in which an exhaust pipe having a reed is mounted and thus the reed generates sound when air is discharged, Korean Unexamined Patent No. 1995-26470 discloses an elastic plate which generates sound to warn overload of a motor using air passing through an air passage, Korean Unexamined Utility Model No. 1995-8227 discloses a whistle to warn over-dust by generating sound using the velocity of airflow caused by difference between internal and external pressure, U.S. Patent No. 4,463,473 discloses a sound producing cylinder and a sound control cylinder, in which if a suction force exceeds a predetermined level, external air flows in through a bypass passage, and thus the air causes the sound producing cylinder and the sound control cylinder to produce sound, U.S. Unexamined Patent No. 2007-180649 discloses a light emitting diode (LED) lamp or a sound generator which is operated if the amount of dust sensed by a dust sensor exceeds a predetermined amount, and Japanese Unexamined Patent No. H 4-338436 discloses a speaker which is configured to inform a user of a cleaning state if a dust sensor senses dust particles. [5] However, such conventional vacuum cleaners merely generate sound or not, and it is difficult to adjust the volume of the sound. The vacuum cleaners disclosed in U.S. Patent Laid Open No. 2007-180649 and Japanese Patent Laid Open H4-338436 cannot enable a user to recognize a cleaning state by adjusting the volume or tone of the sound according to the amount of dust particles contained in air. Disclosure of Invention Technical Problem

[6] To achieve the above object, the present invention provides a vacuum cleaner which generates sound having different tone or volume according to the amount of dust particles contained in air, and thus enables a user to easily recognize the current cleaning state. Solution to Problem

[7] According to an aspect of the present invention, there is provided a vacuum cleaner, including a cleaner body; a nozzle assembly which is connected to the cleaner body; an air passage which is formed from the cleaner body to the nozzle assembly; a dust sensor which is mounted on the cleaner body or the nozzle assembly, and detects the amount of dust particles passing through the air passage; a sound generator which generates sound by a velocity of airflow; and a controller which controls the sound generator according to a signal output from the dust sensor; wherein the controller changes the sound generated by the sound generator according to the amount of dust particles detected by the dust sensor.

[8] The controller may increase the velocity of airflow in the sound generator if the amount of dust particles detected by the dust sensor is increased.

[9] The controller may change the tone or volume of sound generated by the sound generator according to the variation of the amount of dust particles detected by the dust sensor.

[10] The sound generator may include a fan; a motor which drives the fan; a fan casing which covers the fan; and sound generating materials which are disposed in the fan casing. The sound generator may further include a circulation duct which is connected to the fan casing.

[11] The sound generator may include a bypass duct which is connected to the air passage; sound generators which are provided in the bypass duct; and a valve which opens and closes the bypass duct.

[12] The sound generator may be mounted on the cleaner body or the nozzle assembly.

[13] According to another aspect of the present invention, there is provided a vacuum cleaner, including a cleaner body; a nozzle assembly which is connected to the cleaner body; an air passage which is formed from the cleaner body to the nozzle assembly; a dust sensor which is mounted on the cleaner body or the nozzle assembly, and detects the amount of dust particles passing through the air passage; a sound generator which is mounted on the cleaner body or the nozzle assembly, and generates sound by a velocity of airflow; and a controller which controls the sound generator according to a signal output from the dust sensor, wherein the controller controls the sound generator to generate sound only when the vacuum cleaner operates to draw in dust-laden air and thus the dust sensor senses that dust particles are drawn in.

[14] The controller may change the sound generated by a tone or a volume of the sound generator according to the increase of the amount of dust particles detected by the dust sensor.

[15] The controller may change the tone or volume of the sound generated by the sound generator according to the variation of the dust particles detected by the dust sensor.

Advantageous Effects of Invention

[16] As described above, according to exemplary embodiments of the present invention, air flows at various velocity, and sound generating materials which move at different velocity according to the velocity of airflow generate sound having different tone or volume. Accordingly, the vacuum cleaner according to the exemplary embodiments of the present invention enables a user to recognize the cleaning state in more detail.

Brief Description of Drawings [17] FIG. 1 is a schematic block diagram illustrating a vacuum cleaner according to an exemplary embodiment of the present invention; [18] FIG. 2 is an explode perspective view illustrating a sound generator mounted in a vacuum cleaner according to an exemplary embodiment of the present invention; [19] FIG. 3 is a schematic view illustrating a sound generator mounted in a vacuum cleaner according to an exemplary embodiment of the present invention; [20] FIG. 4 is an explode perspective view illustrating a sound generator mounted in a vacuum cleaner according to another exemplary embodiment of the present invention; [21] FIG. 5 is a schematic view illustrating a sound generator mounted in a vacuum cleaner according to another exemplary embodiment of the present invention.

Best Mode for Carrying out the Invention [22] Hereinbelow, a vacuum cleaner according to an exemplary embodiment of the present invention will be explained with reference to the accompanying drawings. FIG.

1 is a schematic block diagram illustrating a vacuum cleaner according to an exemplary embodiment of the present invention. [23] Referring to FIG. 1, a vacuum cleaner 1 according to an exemplary embodiment of the present invention includes a cleaner body 10, a nozzle assembly 30, a dust sensor

35, and a sound generator 50. The vacuum cleaner 1 schematically illustrated in FIG. 1 may be a canister type vacuum cleaner or an upright type vacuum cleaner. If the vacuum cleaner 1 is a canister type vacuum cleaner, a connection member 20 which connects the cleaner body 10 to the nozzle assembly 30 may be formed as an extension pipe (not shown) and a connection hose (not shown), and if the vacuum cleaner 1 is an upright type vacuum cleaner, the connection member 20 may be a connection passage (not shown) which connects the cleaner body 10 to the nozzle assembly 30.

[24] The cleaner body 10 includes a dust separating device 11, and a first air passage 13 which is in fluid communication with the connection member 20 and guides dust-laden air toward the dust separating device 11. The cleaner body 10 further includes a controller 15 to controls various elements such as a suction motor (not shown) which operates in the cleaner body 10.

[25] The nozzle assembly 30 includes a suction port 31 to suck in dirt or dust from a surface being cleaned and a second air passage 33 to connect the suction port 31 to the connection member 20. The nozzle assembly 30 further includes a dust sensor 35 to detect the amount of dust particles contained in air passing through the suction port 31.

[26] The dust sensor 35 is mounted on the suction port 31, and generates a dust sensing signal according to the amount of dust particles contained in air. The dust sensor 35 does not generate a dust sensing signal when air flowing through the nozzle assembly 30 does not contain dust particles while the vacuum cleaner 1 operates. The dust sensor 35 is electrically connected to an input port of the controller 15, and transfers the generated dust sensing signal to the controller 15.

[27] The sound generator 50 is mounted on a portion of the cleaner body 10, and is electrically connected to an output port of the controller 15.

[28] Referring to FIG. 2, the sound generator 50 includes a fan casing 51, a driving motor

54, a fan 55, a circulation duct 57, and sound generating materials 58.

[29] The fan casing 51 is formed with an upper and lower fan casings 51a, 51b to completely cover the fan 55. The upper fan casing 51a is detachably attached to the lower fan casing 51b so as to make it easy to maintain and repair the fan 55. In this connection between the upper and lower fan casings 51a, 51b, an engaging means between conventional members, that is, a rib (not shown) is formed on a periphery of the upper and lower fan casings 51a, 51b, and the engaging members such as a screw (not shown) may connect the upper and lower fan casings 51a, 51b. First and second through holes 53a, 53b disposed apart from each other at a predetermined interval are formed on the fan casing 51.

[30] The driving motor 54 is electrically connected to the output port of the controller 15 so that the controller 15 drives the driving motor 54. In this situation, the driving motor 54 is disposed on a side of the fan casing 51, and transfers driving mechanism to the fan 55. [31] The fan 55 serves as a turbine fan, and is rotatably disposed inside the fan casing 51.

An engaging hole 55a into which a rotating shaft 54a of the driving motor 54 is inserted is formed on a rotating center of the fan 55. The fan 55 is rotated by the driving motor 54, and generates the velocity of airflow in the fan casing 51 and the circulation duct 57.

[32] Both ends of the circulation duct 57 are inserted into the first and second through holes 53a, 53b of the fan casing 51, respectively. The airflow which is moved by the driving fan 55 rotating in the fan casing 51 at a predetermined velocity is circulated along with the circulation duct 57 in one direction.

[33] The sound generating materials 58 serves as beads. The airflow produced by the driving fan 55 causes the sound generating materials 58 to move in the fan casing 51 and the circulation duct 57 in a predetermined direction. The sound generating materials 58 generate sound by colliding with one another, or by colliding with the fan 55 or an internal wall of the circulation duct 57. Such sound generating materials 58 may be made of resin having adequate rigidity and elasticity in consideration of the durability of the fan casing 51, the fan 55, and the circulation duct 57.

[34] The sound generator 50 is mounted on the cleaner body 10 in this exemplary embodiment of the present invention, but this is not limited thereto. Alternatively, the sound generator 50 may be mounted on the nozzle assembly 30, or on a handle (not shown) of the vacuum cleaner 1 so that a user can clearly listen to the sound generated by the sound generator 50 without any noise caused by the suction motor (not shown) of the vacuum cleaner 1 or the nozzle assembly 30.

[35] The operation of the vacuum cleaner having such sound generator 50 will be explained with reference to FIGS. 1 and 3.

[36] The vacuum cleaner 1 is turned on and thus draws in dust-laden air from a surface being cleaned through the nozzle assembly 30. The dust sensor 35 detects the amount of dust particles contained in the air passing through the suction port 31, and generates a dust generating signal corresponding to the detected amount.

[37] The controller 15 receives dust generating signals which are different according to the amount of dust particles contained in air from the dust sensor 35, and controls the speed of the driving motor 54 according to the dust generating signal. That is, if the amount of dust particles contained in air detected by the dust sensor 35 is increased, the controller 15 increases the rotational speed of the fan 55, thereby increasing the velocity of airflow in the fan casing 51 and the circulation duct 57.

[38] The sound generating materials 58 circulate in the fan casing 51 and in the circulation duct 57 by airflow which is generated in the fan casing 51 and in the circulation duct 57, as shown in FIG. 3. In this situation, the sound generating materials 58 generate predetermined sound by colliding with one another, or colliding with the internal wall of the fan casing 51, the fan 55, or the internal wall of the circulation duct 57.

[39] If the velocity of airflow is increased, the sound generating materials 58 circulate faster in the casing 51 and in the circulation duct 57. Accordingly, collision may occur continuously, thereby generating higher or louder sound.

[40] Accordingly, the tone or volume of the sound generated by the sound generator 50 is varied according to the amount of dust particles in air drawn in through the nozzle assembly 30, and this enables a user to easily recognize the current cleaning state only by listening to the sound generated by the sound generator 50.

[41] FIG. 4 is an explode perspective view illustrating a sound generator 50a mounted in a vacuum cleaner according to another exemplary embodiment of the present invention.

[42] The sound generator 50a may be configured without the circulation duct 57 as shown in FIG. 4.

[43] The sound generator 50a includes the fan casing 51, the driving motor 54, the fan 55, and the sound generating materials 58. The driving motor 54, the fan 55, and the sound generating materials 58, except for the fan casing 51, in FIG. 4 are identical to those in FIG. 2, and thus detailed description thereof will be omitted.

[44] The fan casing 51 is formed with the upper and lower fan casings 51a, 51b to completely cover the fan 55. An air inlet 59a through which external air enters the fan casing 51 is formed on a part of the upper fan casing 51a, and an air outlet 59b through which internal air goes out is formed on another part of the upper fan casing 59b.

[45] First and second nets 59c, 59d which are woven tighter to have smaller holes than the size of the sound generating materials 58 are mounted over the air inlet 59a and the air outlet 59b, respectively, so that the sound generating materials 58 do not escape from the fan casing 51 through the air inlet 59a and the air outlet 59b.

[46] The air inlet 59a and the air outlet 59b allow external or internal air to enter or exit the fan casing 51 when the fan 55 rotates. Accordingly, airflow having predetermined velocity is formed in the fan casing 51. The airflow enables the air generating materials 58 to circulate in the fan casing 51, and the air generating materials 58 generate sound by colliding with the internal wall of the fan casing 51 or with the fan 55.

[47] The air inlet 59a and the air outlet 59b are formed on the upper fan casing 51a, but this is not limited thereto. Alternatively, the air inlet and outlet 59a, 59b may be formed on any portion of the fan casing 51a so that internal or external air flows out or into the fan casing 51.

[48] FIG. 5 is a schematic view illustrating a sound generator mounted in a vacuum cleaner according to another exemplary embodiment of the present invention.

[49] The sound generator 150 may generate sound using airflow which flows along the first air passage 13 without forming airflow by the fan 55 as shown in FIG. 5. [50] The sound generator 150 includes a bypass duct 157, the sound generating materials

158 and a valve 159.

[51] An air inlet 157a formed on an end of the bypass duct 157 and an air outlet 157b formed on an opposite end of the bypass duct 157 fluidly communicate with the first air passage 13 at a predetermined interval. In this case, the air inlet 157a is disposed higher than the air outlet 157b with respect to the direction in which air flows along the first air passage 13.

[52] First and second nets 157c, 157d which are woven tighter than the size of the sound generating materials 158 are mounted over the air inlet 157a and the air outlet 157b, respectively, so that the sound generating materials 158 do not escape from the bypass duct 157 through the air inlet 157a and the air outlet 157b.

[53] The valve 159 is mounted on the air inlet 157a to open and close the air inlet 157a.

For example, the valve 159 may serve as a solenoid valve which can be electrically controlled. The valve 159 is electrically connected to the controller 15, and thus controlled by the controller 15.

[54] The controller 15 may control the amount of dust-laden air drawn into the bypass duct 157 by controlling not only whether to open or close the valve 159 but also the degree of opening the valve 159 according to the amount of dust particles in air detected by the dust sensor 35. In this situation, the more the amount of dust-laden air flowing into the bypass duct 157 is, the faster the dust-laden air flows in the bypass duct 157.

[55] The sound generating materials 158 are configured in the same manner as the above described sound generating materials 158, and generate sound by colliding with one another, or by colliding with an internal wall of the bypass duct 157. In addition, if the velocity of airflow is increased, the sound generating materials 158 collide with one another faster, and thus generate louder sound.

[56] The sound generating materials 158 are provided in the first air passage 13 in this exemplary embodiment of the present invention, but this is not limited thereto. The sound generating materials 158 may be provided in any element through which dust- laden air flows, for example, the connection member 20 or the second air passage 33.

[57] The above described sound generators 50, 50a, 150 may be applied to not only an upright type vacuum cleaner or a canister type vacuum cleaner but also a robot cleaner.

[58] Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.