Electric vacuum cleaner and dust collecting unit for use therein

[0001] 1. Field of the Invention

[0002] The present invention relates to an electric vacuum cleaner and a dust collecting unit for use therein, and especially to so-called a cyclone type electric vacuum cleaner and a dust collecting unit for use therein.

[0003] 2. Description of the Related Art

[0004] The inventors of the present application have proposed a prior invention of so-called a cyclone type electric vacuum cleaner in Japanese Patent Application No. 2003-94416. This proposed electric vacuum cleaner has a cyclone cylindrical body disposed in the center of a dust collecting chamber and an air discharge cylinder disposed in the center of the cyclone cylindrical body, and performs operations of causing air led into the dust collecting chamber to swirl along the outer circumferential surface of the cyclone cylindrical body and thereby separating relatively large-sized or coarse dust from air. Then, air from which relatively large-sized dust has been separated is led into the cyclone cylindrical body, and the air is swirled in the space between the air discharge cylinder and the cyclone cylindrical body by a swirl air flow generating means. Thereby, minute dust is separated from the air and accumulated in the lower part inside the cyclone cylindrical body. The air from which minute dust has been separated is led through the air discharge cylinder to the outside of the dust collecting container. With such a structure, the axial length of the cyclone cylindrical body disposed in the dust collecting chamber can be shortened and thereby the dust collecting unit can be miniaturized.

[0005] However, in the invention of the abovementioned prior application, since the axial length of the cyclone cylindrical body is short, minute dust, though in a little amount, is not separated from air and apt to be discharged together with the air to the outside of the dust collecting container. For solving this problem, it can be proposed that a dust collecting filter is provided in a stream of the dust collecting unit. However, such an arrangement causes a new problem that troublesome operations are required for attaching and detaching such dust collecting filter or the like at the maintenance time.

[0006] The present invention has been made in order to solve the abovementioned problems. And an object of the present invention is to provide an electric vacuum cleaner of a high dust collecting efficiency though it has a miniaturized dust collecting unit.

[0007] Another object of the present invention is to provide an electric vacuum cleaner having a dust collecting filter of an improved maintenance property, and a dust collecting unit for use in the electric vacuum cleaner.

[0008] A further object of the present invention is to provide a dust collecting unit suitable for use in a cyclone type electric vacuum cleaner.

[0009] The present invention is, to sum up, an electric vacuum cleaner and a dust collecting unit for use therein, the electric vacuum cleaner includes a dust collecting container into which air sucked at the cleaning time is led and a cyclone mechanism for causing air entering into the dust collecting container to swirl thereby to separate dust contained in the air from the air, and is characterized by further including a filter outside the dust collecting container for catching minute dust contained in air discharged from the dust collecting container.

[0010] According to the present invention, minute dust not removed from air by the cyclone mechanism in the dust collecting container can be surely caught by the filter provided outside the dust collecting container. Further, since the filter is provided outside the dust collecting container, it has a good maintenance property for cleaning, exchange and the like.

[0011] Preferred embodiments of the present invention will be described below with reference to the appended drawings. The description of the embodiments below does not limit the claims of the present invention but is only for understanding of the invention.

[0012] FIG. 1 is a view showing the schematical structure of an upright type electric vacuum cleaner according to an embodiment of the present invention.

[0013] FIG. 2 is a vertical sectional view showing the structure of a dust collecting unit according to an embodiment of the present invention in which a filter is in the closed state.

[0014] FIG. 3 is a vertical sectional view showing the structure of a dust collecting unit according to an embodiment of the present invention in which the filter is in the opened state.

[0015] The structure of an upright type electric vacuum cleaner according to an embodiment of the present invention will be now described.

[0016] FIG. 1 is a schematical view of an upright type electric vacuum cleaner according to an embodiment of the present invention. The electric vacuum cleaner 100 includes a suction section 2 movable along floor surfaces. The suction section 2 has a suction port 1 open to the floor surfaces, and a rotary brush (not shown) is provided within the suction port 1. The suction section 2 is pivotally supported by a cleaner main body 3 of the electric vacuum cleaner 100 and communicated with the inside of the cleaner main body 3. Provided in the upper portion of the cleaner main body 3 is a handle 4 extending upward. A dust collecting unit 5 is removably mounted on the cleaner main body 3. Within the cleaner main body 3 provided is an electric blower (not shown) below the dust collecting unit 5. When the electric blower is operated, air containing dust is sucked through the suction section 2 and led into the dust collecting unit 5. Then, the dust is separated from the air in the dust collecting unit 5 and the cleaned air is discharged from the lower portion of the cleaner main body 3.

[0017] The dust collecting unit 5 has a grip 41 in the upper portion, so that a user can detach the dust collecting unit 5 from the cleaner main body 3 by holding the grip 41 with his or her hand. The main part of the dust collecting unit 5 is formed into a cylindrical shape of a transparent or semi-transparent resin.

[0018] FIG. 2 is a vertical sectional view of the dust collecting unit 5 detached from the cleaner main body 3 in which a filter 25 is in the closed state. Further, FIG. 3 is a vertical sectional view of the dust collecting unit 5 in which the filter 25 is in the open state. Now, the structure of the dust collecting unit 5 will be described in detail with reference to FIGS. 2 and 3.

[0019] The dust collecting unit 5 includes a cylindrical container 51. The container 51 has so-called a vertical cylindrical shape in which the central axis thereof extends in the vertical direction. The container 51 is formed of a transparent or semi-transparent resin. Provided in the upper portion of the inside of the container 51 is a partition wall 6 spreading in the horizontal direction. A holding mechanism room 10 is provided above the partition wall 6. Within the holding mechanism room 10, though not shown, contained is a mechanism for holding a cyclone mechanism 52 disposed in the space below the partition wall 6. The holding mechanism is operated from outside the container 51 so as to attach the cyclone mechanism 52 to the container 51 or detach the cyclone mechanism 52 from the container 51. However, since it is not the main subject of the present invention, further detailed description thereof is omitted.

[0020] A space defined by a lower surface of the partition wall 6 and the container 51 constitutes a dust collecting chamber 8. Being defined by the inner circumferential surface of the cylindrical container 51, the side surface of the dust collecting chamber 8 is formed into a cylindrical shape. The container 51 has an air suction port 11 so that air can be sucked along the inner circumferential surface of the cylindrical dust collecting chamber 8. The air suction port 11 is provided in the upper portion of the dust collecting chamber 8. An opening 7 is formed at the bottom portion of the dust collecting chamber 8 and the opening 7 is covered by closing a lid 12. The lid 12 is pivoted to one side of the bottom portion of the container 51 so as to make pivotal movement. At the other side of the bottom portion of the container 51, a clamp 13 is provided. The clamp 13 holds (locks) the lid 12 in the state in which the lid 12 closes the lower opening 7 of the container 51. An operating member 14 is provided near the clamp 13. By pressing the operating member 14 in the downward direction, the clamp 13 pivotally moves and the lid 12 is unlocked. An air outlet port 15 is provided substantially in the center of the lid 12. The air outlet port 15 is communicated with a lower end 23 of an air discharge cylinder 17 which will be mentioned below.

[0021] The outside of the dust collecting chamber 8, namely, the lower opening 7 of the dust collecting chamber 8 is closed by the lid 12, and the filter 25 is provided below the lid 12. The filter 25 is disposed so as to oppose to the air outlet port 15 provided in the lid 12. And as mentioned below, air discharged from the air outlet port 15 is led through the filter 25 to the electric blower (not shown).

[0022] Now, the structure of the cyclone mechanism 52 provided in the dust collecting chamber 8 will be described.

[0023] The cyclone mechanism 52 includes a primary separation cylinder 9 having a vertical central axis and formed in a circular cylindrical shape, a circular cylinder 16 coaxially disposed inside the primary separation cylinder 9, and the air discharge cylinder 17 formed in a cylindrical shape and coaxially disposed inside the circular cylinder 16.

[0024] The vertical length of the primary separation cylinder 9 is about the upper half of the vertical length of the dust collecting chamber 8. A plurality of air holes 18 are provided in the circumferential surface of the primary separation cylinder 9 except the upper circumferential surface opposed to the air suction port 11. A downwardly and outwardly spreading skirt 19 is extended from the lower end of the primary separation cylinder 9. The space between the skirt 19 and the inner circumferential surface of the container 51 becomes narrow since the skirt 19 spreads downwardly and outwardly from the lower end of the primary separation cylinder 9. As a result, the region below the skirt 19 in the dust collecting chamber 8 serves as a region for storing dust.

[0025] Air (air containing dust) introduced through the air suction port 11 into the dust collecting chamber 8 swirls along the inner circumferential surface of the container 51 and enters through the plurality of air holes 18 provided in the circumferential surface of the primary separation cylinder 9 into the primary separation cylinder 9. At this time, due to the swirling of the air along the inner circumferential surface of the container 51, dust in rather large sizes contained in the air is separated below and drops through the space between the skirt 19 and the inner circumferential surface of the container 51 downwardly to be accumulated at the bottom of the dust collecting chamber 8.

[0026] The upper part of the circular cylinder 16 provided in the primary separation cylinder 9 is coaxially disposed inside the primary separation cylinder 9 and the lower part thereof extends to the bottom of the dust collecting chamber 8. And the circular cylinder 16 and the skirt 19 of the primary separation cylinder 9 are removably connected to each other through an outwardly stretched flange 20 disposed substantially in the center of the circular cylinder 16.

[0027] Above the flange 20, an air inlet port 21 is provided so as to open a part of the circumferential surface of the circular cylinder 16. Further, the circular cylinder 16 is provided with a dust outlet port 22 near the upper end of the circumferential surface thereof.

[0028] Air introduced into the primary separation cylinder 9 through the air holes 18 thereof enters into the circular cylinder 16 through the air inlet port 21 provided in the circular cylinder 16. Then, swirling in the ring-shaped space when seen in a plan view defined by the inner circumferential surface of the circular cylinder 16 and the outer circumferential surface of the air discharge cylinder 17 disposed in the circular cylinder 16, the air flows upwardly, so that dust in the air is separated and the separated dust is discharged through the dust outlet port 22 to the outside of the circular cylinder 16. And the discharged dust drops down to the lower part of the dust collecting chamber 8.

[0029] The upper end of the air discharge cylinder 17 coaxially disposed inside the circular cylinder 16 opens at a position a little higher than the middle position of the height of the circular cylinder 16. Further, the lower part of the air discharge cylinder 17 extends downwardly similarly to the lower part of the circular cylinder 16, and the lower end 23 thereof is communicated with the air outlet port 15 provided in the lid 12.

[0030] The position of the opened upper end of the air discharge cylinder 17 has only to be higher than the air inlet port 21 of the circular cylinder 16 and lower than the dust outlet port 22.

[0031] Further, in the space defined by the inner circumferential surface of the circular cylinder 16 and the outer circumferential surface of the air discharge cylinder 17, a spiral blade 24 is provided as a swirl air flow generating means. The spiral blade 24 is an elongated projection on the outer circumferential surface of the air discharge cylinder 17, and it starts from a position opposed to the air inlet port 21 of the circular cylinder 16 and spirally extends upwardly on the outer circumferential surface of the air discharge cylinder 17. The top (ridge) of the elongated projection is close to or in contact with the inner circumferential surface of the circular cylinder 16. Therefore, air entering through the air inlet port 21 is guided by the spiral blade 24 to flow swirling in the upward direction. Thereby minute dust is separated from the air. The separated minute dust is discharged to the outside of the circular cylinder 16 through the dust outlet port 22 provided at the upper position of the circular cylinder 16. And air which flows swirling upwardly enters the air discharge cylinder 17 through the upper opening of the air discharge cylinder 17 and flows downwardly to be discharged through the air outlet port 15 to the outside of the container 51.

[0032] The filter 25 is provided outside the container 51, namely, below the lid 12. The filter 25 is disposed in a position opposed to the air outlet port 15 as abovementioned, so that air discharged from the air outlet port 15 passes through the filter 25.

[0033] The filter 25 has a triple layer structure comprising a first filter 26 formed of rough urethane or the like, a second filter 27 formed of unwoven cloth or the like and a third filter 28 of a pleated structure for removing minute dust, in the order seen from the upstream side. The filter 25 is contained in a filter case 29. The filter case 29 is pivoted at one side by the lid 12 so as to make pivotal movement. The other side of the filter case 29 is provided with a click 30 which can engage with a projection provided on the lid 12.

[0034] With such arrangements, the filter case 29 can be shifted between the closed state in which the filter case 29 is disposed in the horizontal direction below the lid 12 thereby to close the air outlet port 15 as shown in FIG. 2 and the open state in which the filter case 29 is disposed in the vertical direction thereby to open the air outlet port 15 as shown in FIG. 3.

[0035] Further, though not shown, the filter case 29 containing the filter 25 inside may be adapted to be removable from the lid 12.

[0036] The filter 25 has the triple layer structure as abovementioned. The third filter 28 is of the pleated structure for improving the dust collecting efficiency. With such a structure, in a case the second filter 27 is not present and the space between the first filter 26 and the third filter 28 is so narrow that, for example, the first filter 26 and the third filter 28 are in contact with each other, air is liable not to flow through the part of the third filter 28 corresponds to a plugged part of the first filter 26when the first filter 26 is plugged. In such a case, the dust collecting efficiency of the third filter 28 is lowered and at the same time the life of the third filter 28 becomes shorter.

[0037] Therefore, in this embodiment, the second filter 27 is provided between the first filter 26 and the third filter 28. In addition to the main function of catching dust, the second filter 27 has another function as a spacer keeping a predetermined space between the first filter 26 and the third filter 28. With such a structure, even if a part of the first filter 26 is plugged, air can flow through the third filter 28 in correspondence to the plugged part of the first filter 26 by means of the second filter 27. As a result, the life of the third filter 28 can be prevented from becoming shorter and at the same time the dust collecting efficiency can be prevented from being lowered.

[0038] With reference to FIGS. 1 and 2, the whole air flow in the electric vacuum cleaner 100 will be briefly explained. Air containing dust sucked through the suction port 1 of the suction section 2 is introduced into the dust collecting chamber 8 of the dust collecting unit 5. At this time, while the air enters the dust collecting chamber 8 in the swirling direction along the inner circumferential surface of the container 51, relatively large-sized dust and the like is separated from the air and falls down to the lower region of the dust collecting chamber 8 defined by the skirt 19 thus to be accumulated on the lid 12.

[0039] Air from which relatively large-sized dust is removed is led through the air holes 18 of the primary separation cylinder 9 and the air inlet port 21 of the circular cylinder 16 into the circular cylinder 16. Then, the air is guided by the spiral blade 24 provided on the outer circumferential surface of the air discharge cylinder 17 to become a swirl air flow, which goes swirling upwardly in the circular cylinder 16. By this upward swirl air flow, minute dust is separated from the air. The separated minute dust is discharged through the dust outlet port 22 to the outside of the circular cylinder 16 to be accumulated in the lower part of the dust collecting chamber 8.

[0040] The air from which the minute dust is removed passes through the upper opening of the air discharge cylinder 17, falls down in the air discharge cylinder 17, is discharged below from the air outlet port 15 and flows through the filter 25 to the electric blower (not shown). If a slight amount of minute dust is left in the air passing through the filter 25, the filter 25 catches such minute dust.

[0041] In order to removing away dust accumulated in the dust collecting unit 5, the lid 12 has only to be opened. When the lid 12 is opened, dust accumulated in the lower part of the dust collecting chamber 8 falls down by its own weight.

[0042] In this embodiment, the filter 25 is disposed outside of the dust collecting chamber 8, namely, on the lower side of the lid 12. In other words, the filter 25 is disposed outside the dust collecting chamber 8 and on the downstream side of the air outlet port 15 when seen in the direction of air flow. Therefore, if the dust collecting unit 5 is miniaturized and a slight amount of minute dust is still left in air from which dust has been separated by the cyclone mechanism, such dust left in the air can be surely caught by the filter 25. As a result, the dust collecting unit 5 can be miniaturized without lowering the dust collecting efficiency thereof.

[0043] In order to clean, exchange or the like the filter 25, the filter case 29 has only to be opened as shown in FIG. 3. By opening the filter case 29, the condition of the filter 25 can be easily confirmed from outside of the dust collecting unit 5, so that the maintenance property of the filter 25 can be improved.

[0044] In the abovementioned embodiment, the dust collecting chamber 8 is formed by the container 51 and the lid 12, but it is not limited to such a structure. It is also possible that the container is in the shape of a cylinder having closed bottom and opened upper end and the lid for closing the opened upper end of the container is not provided on the container so as to be closed and opened but provided on the cleaner main body side. In this case, it is possible that the air outlet port of the dust collecting unit is provided, for example, in the circumferential surface of the container and the filter is fitted to the outside of the container.

[0045] Further, in the abovementioned embodiment, the air outlet port is provided at the bottom of the dust collecting unit 5. However, the air outlet port can be provided in the upper surface, side surface or the like of the dust collecting unit 5. In such cases, the fitting position of the filter can be changed in correspondence with the position of the air outlet port.

[0046] In the above-described structure, the spiral blade 24 as a swirl air flow generating means within the dust collecting chamber 8 is provided on the outer circumferential surface of the air discharge cylinder 17. However, the spiral blade 24 may be provided on the inner circumferential surface of the circular cylinder 16.

[0047] Further, the present invention can be applied not only to an upright type electric vacuum cleaner but also to a canister type electric vacuum cleaner.

[0048] Furthermore, the present invention can be variously changed within the scope of claims.