Dirt collecting device for a cleaning device, particularly a sweeping vehicle, and vacuum cleaner nozzle for a vacuum cleaner, and method for operating both devices

Abstract

Method for operating a dirt collecting device for a sweeping vehicle or for a vacuum cleaner nozzle of a floor or upright vacuum cleaner, which each comprise a suction fan with controllable speed and/or power, wherein in a first method step, the suction power of the suction fan is set at such a low level that the suction pressure in the dirt collecting device or the vacuum cleaner nozzle is merely sufficient to convey and deposit the absorbed coarse dirt into the intermediate container, and to convey the absorbed fine dirt into a downstream collection container, (normal operation); and that in a second method step, the filling level in the intermediate container is detected with respect to the coarse dirt deposited therein; and that in a third method step, if the filling level in the intermediate container is exceeded, the suction power of the suction fan is increased such that the coarse dirt, which is temporarily deposited in the intermediate container, becomes dispersible and is conveyed into the downstream collection container (emptying mode).

Claims

1. A method for operating a dirt collecting device for a sweeping vehicle or for a vacuum cleaner nozzle of a floor or upright vacuum cleaner, each having a suction fan with controllable speed and/or power, wherein in a first method step, which corresponds to normal operation, the suction power of the suction fan is set at such a low level that the suction pressure in the dirt collecting device or the vacuum cleaner nozzle is merely sufficient to convey and deposit the input coarse dirt into the intermediate container, and to convey the input fine dirt into a downstream collection container; in a second method step, the filling level in the intermediate container is detected with respect to the coarse dirt deposited therein; and in a third method step, which corresponds to an emptying mode, if the filling level in the intermediate container is exceeded, the suction power of the suction fan is increased such that the coarse dirt, which is temporarily deposited in the intermediate container, becomes dispersible and is conveyed into the downstream collection container.

2. The method according to claim 1, wherein for the operation of a dirt collecting device for a sweeping vehicle, the airflow of the suction fan is approximately doubled from the first method step to the third method step.

3. The method according to claim 1, wherein for the operation of a vacuum cleaner nozzle, the energy consumption of the suction fan is approximately tripled from the first method step to the third method step.

4. The method according to claim 1, wherein the surface located in the suction airflow of the suction fan of the dirt collecting device for a sweeping vehicle is in a range between 20 to 100×10.sup.−3 m2, and the same surface of the vacuum cleaner nozzle is in a range between 1 to 5×10.sup.−3 m2.

Description

(1) In the following, the invention shall be described in more detail using drawings showing only one embodiment. Further features and advantages essential to the invention can be derived from the drawings and their description.

(2) FIG. 1 shows schematically the structure of a sweeping vehicle without chassis or similar parts;

(3) FIG. 2 shows a perspective view of the dirt collecting device for the sweeping vehicle according to FIG. 1;

(4) FIG. 3 shows a view from the bottom of the dirt collecting device according to FIG. 1;

(5) FIG. 4 shows the cross-section of a dirt collecting device according to FIGS. 2 and 3 when inputting coarse dirt;

(6) FIG. 5 shows the cross-section of the dirt collecting device according to FIG. 4 when inputting fine dirt as well as a depiction of further details not yet shown in FIG. 4;

(7) FIG. 6 shows the top view of a vacuum cleaner nozzle with a rotatingly driven brush roller;

(8) FIG. 7 shows the cross-section of the vacuum cleaner nozzle according to FIG. 6;

(9) FIG. 8 shows schematically the depiction of the sensor signals of the filling level sensor in the intermediate container according to FIG. 1 or 7;

(10) FIG. 9 shows the intermittent air speed in a dirt collecting device for a sweeping vehicle on the basis of the sensor signal of the filling level sensor;

(11) FIG. 10 shows the intermittent energy consumption of the suction fan of a sweeping vehicle;

(12) FIG. 11 shows the intermittent energy consumption of the suction fan for a vacuum cleaner;

(13) FIG. 12 shows the air speed of a suction fan for a vacuum cleaner during intermittent operation;

(14) FIG. 13 shows the depiction of the energy consumption of the suction fan of a sweeping vehicle plotted against the percentage of the operating time at low air speed;

(15) FIG. 14 shows a table showing the energy consumption of the suction fan of a sweeping vehicle at normal operation and in emptying mode;

(16) FIG. 15 shows a table regarding the time portion of the operation of a sweeping machine relative to the energy consumption.

(17) In the present description of the invention, both the features of a dirt collecting device 2 for a cleaning device, particularly a sweeping vehicle, and the features of a vacuum cleaner nozzle 20 for a floor or upright vacuum cleaner are described; therefore, the same reference signs apply to all parts. For reasons of simplification, no reference was made to the suction fan and a collection container in the description of the operation of a floor or upright vacuum cleaner. The relevant information is part of the disclosure of the aforementioned U.S. Pat. No. 5,500,979 A1. Reference is herewith made to that description.

(18) In particular, FIG. 14 in said document shows a complete depiction of an upright vacuum cleaner having a suction fan, a collection container, and an associated fine mesh filter. All these parts are also parts of the present invention.

(19) FIG. 1 shows schematically the airflow in a sweeping vehicle which, for example, is described in DE 41 28 879 A1 or EP 2 350 393 B1. All features described therein, particularly chassis, steering, drive, and the like have been omitted in FIG. 1 of the present description of the invention for reasons of simplification.

(20) Accordingly, the sweeping vehicle 1 according to FIG. 1 comprises a dirt collecting device 2 which essentially consists of a housing 26 (see FIG. 2), which, with regard to its cover wall 27, is designed so as to be arch-shaped, and which carries a height-adjustable front spoiler 15 at its front end.

(21) By means of a supporting device (not depicted in FIG. 1), the dirt collecting device 2 according to FIG. 1 is movable over a roadway plane 19, namely by means of the drive of the sweeping vehicle. A rotatingly driven sweeper roller 14 is arranged in the interior of the dirt collecting device 2. During operation of the dirt collecting device 2, the front spoiler 15 is guided in driving direction 13 over the roadway plane 19, and the coarse dirt 17 and possible fine dirt 18 accumulated on said plane is input into the dirt collecting device 2.

(22) It has already been mentioned in the introduction of the description that during normal operation of the dirt collecting device 2, the coarse dirt 17 consists of non-dispersible material, such as stones, bottles, cans, and the like.

(23) However, the fine dirt 18 is immediately input during normal operation of the dirt collecting device 2 and is conveyed in arrow direction 21 to a downstream coarse dirt collection container 4 by means of a connection channel 3.

(24) The outlet of the coarse dirt collection container 4 is connected to a fine dirt collection container 6 by means of a further connection channel 5, and so the fine dirt reaches the filter 7, drops from said filter 7 and is deposited in the fine dirt collection container 6.

(25) Behind the filter 7, a suction fan 8 is arranged which is driven by a motor 9 in a specific rotational direction by means of a driveshaft 11.

(26) The motor can either be an electric drive motor or it can also be derived by means of a coupling and a corresponding intermediate transmission directly from the drive of the sweeping vehicle 1.

(27) The air suctioned by the suction fan 8 in arrow direction 25 over the fine dirt collection container 6 thus flows through the filter 7 and leaves in a cleaned state the outlet of the filter 7 in arrow direction 12.

(28) It has already been pointed out in the general description that the fine dirt collection container 6 can also coincide with the coarse dirt collection container 4, and both containers can form a single container.

(29) However, in the depicted embodiment, the two containers 4, 6 are separate from one another, which has certain operational advantages.

(30) During normal operation, the suction power of the suction fan 8 is reduced such that there is only a reduced airflow in the area of the front side of the front spoiler 15 and in the area of the suction side of the sweeper roller 14, and so with the reduced suction airflow, it is only possible for the sweeper roller 14 to input the coarse dirt 17 from the roadway plane 19 and transport said coarse dirt 17 according to the throw-over principle (or alternatively according to the throw-under principle) in arrow direction 20 to a trough-shaped intermediate container 10, which is open at the top and adjacent to the sweeper roller 14. This is where the coarse dirt is deposited, as is shown in FIG. 1.

(31) However, during normal operation, the input fine dirt 18 is conveyed over the intermediate container 10 in arrow direction 21 either to the coarse dirt collection container 4 and/or the downstream fine dirt collection container 6.

(32) If the filling level in the intermediate container 10, which is monitored by means of a filling level sensor, is so high that it must be emptied, the power of the suction fan 8 is greatly increased and the coarse dirt 17 stored in the intermediate container 10 is made dispersible by said increased suction pressure and transported in arrow direction 21 into the coarse dirt container 4, where it is deposited, as is shown in FIG. 1.

(33) During this emptying mode, the fine dirt, which might still be deposited in the coarse dirt collection container 4, is still transferred to the fine dirt collection container 6.

(34) Therefore, the intermediate container 10 is emptied of the coarse dirt 17, which is now dispersible, in arrow direction 23 into the coarse dirt collection container 4 provided for such purpose. The fine dust possibly still present in the coarse dirt collection container 4 is conveyed further in arrow direction 24 and conveyed in arrow direction 25 against the filter 7, where the fine dirt 18 is separated.

(35) It is not depicted that both the coarse dirt collection container 4 and the fine dirt collection container 6 can be emptied from time to time.

(36) FIGS. 2 to 5 show further details of the dirt collecting device 2 according to the invention.

(37) FIG. 2 shows that additional supporting and drive units 30 can be arranged at the dirt collecting device 2, and so it does not have to be securely attached to the sweeping vehicle 1; it can also be operated separately in driving direction 13 and only be means of a coupling connection with the sweeping vehicle 1.

(38) Furthermore, FIG. 2 shows that in the area of the pivot axis 33, the front spoiler 15 arranged at the front is designed so as to be pivotable in the arrow direction 34 and in the opposite direction thereto, and with sealing lip 35 is provided on the edge of the front spoiler that sealingly bears against the front wall 38, which is associated with the housing 26 of the dirt collecting device 2.

(39) Therefore, the sealing lip 35 of the housing 26, which bears against the front wall 38, is arranged height-adjustably in the arrow directions 36. For that purpose, a rack frame 16 is provided on the side of the housing, and the pivot axis 33 for the pivot mounting of the front spoiler 15 is attached to the free front end of said rack frame 16.

(40) In the area of the suction opening in the front, the front spoiler 15 comprises a cone narrowing 39, and so high air speed is generated in the area of said suction opening, said high air speed being capable of transporting the coarse dirt 17 and the fine dirt 18, accumulated on the roadway plane, at least to the area of operation of the rotatingly driven sweeper roller. The side walls of the front spoiler are supposed to rest on the roadway plane in a preferably sealed manner, or form a slight gap to the roadway plane.

(41) According to FIG. 3, the surface of the front spoiler 15 expands in the direction toward the sweeper roller 14, which thus conveys the collected dirt to an intermediate container 10 arranged in the housing 26 of the dirt collecting device 2, as is shown in FIGS. 4 and 5.

(42) The intermediate container 10 comprises a floor surface 41 which is separated from the area of operation of the sweeper roller 14 only by a cone wall 44 which obliquely slopes toward the rear, and so it is readily possible that the sweeper roller, even at low suction pressure, conveys the coarse dirt 17, according to the throw-over principle in FIG. 4, in arrow direction 43 to the intermediate container 10 arranged in the housing 26.

(43) Generally, the housing 26 comprises a cover wall 27 and two side walls 28 which are parallel to one another and are connected by a rear wall 29 at the rear.

(44) At the front side, a front wall 38 is arranged, and the sealing lip 35 of the front spoiler 15 sealingly bears, height-adjustably in arrow directions 36 (see FIG. 2 and FIG. 4), against said front wall 38.

(45) For receiving the coarse dirt, the front spoiler can thus swivel upward, and the coarse dirt on the roadway plane 19, e.g. a can, is thus conveyed to the area of operation of the sweeper roller 14. The sweeper roller 14 forms a receiving space 76, which narrows toward the bottom, and the suction pressure prevailing during normal operation bears against said receiving space 76.

(46) Essentially, the suction pressure is merely suitable for conveying the fine dirt 18 to the intermediate container 10, and the coarse dirt is essentially also only transported to the area of operation of the sweeper roller 14 and conveyed from there by the sweeper roller 14 in arrow direction 43, according to the throw-over principle, to the intermediate container 10, where the coarse dirt is shown with reference sign 17′ in FIG. 4.

(47) Due to the reduced suction pressure during normal operation, the arrow direction 43 (conveying direction of the sweeper roller 14) is thus split or divided because the fine dirt 18 from arrow direction 46 is split, and due to the reduced suction pressure is conveyed through the connection channel 3 at least into the coarse dirt collection container 4.

(48) By contrast, the coarse dirt is deposited in arrow direction 46 on the floor surface 41 of the intermediate container 10.

(49) At the front, the intermediate container is delimited by an obliquely running cone wall 44 (see FIG. 4), wherein the floor surface 41 is designed so as to be approximately parallel to the roadway plane 19 and is closed in the rear by a settling wall 45, and so a sufficiently high filling height of coarse dirt 17 is possible in the intermediate container 10. This is shown in FIG. 5. FIG. 5 schematically shows a maximum filling level 51 in the intermediate container 10, and it further shows that the filling level sensor 49 with its measuring beam 50 scans the surface of the coarse dirt in the intermediate container 10 and generates a signal according to FIG. 8, when the maximum permissible filling level 51 is reached.

(50) Alternatively, such a filling level sensor 49 can also be substituted by horizontally measuring filling level sensors 49′ which laterally detect the filling level in the intermediate container 10.

(51) According to the general description, mechanical scanning feelers can also be used.

(52) In conjunction with FIG. 3, FIG. 2 also shows that the support and drive units of the dirt collecting device 2 can also consist of rollers which are designed so as to be vertically height-adjustable in arrow direction 32.

(53) On its sides, the front spoiler 15 also comprises conically expanding side spoilers 37, and the housing 26 of the dirt collecting device 2 is also preferably sealed on the bottom side with regard to the roadway plane 19, or only leaves open a slight gap in order to generate the highest possible suction pressure only in the area of the front spoiler 15, particularly in the area, where the coarse and fine dirt 17, 18 is supposed to be collected.

(54) FIG. 3 further shows that the side boundaries of the intermediate container 10 taper preferably conically in the direction of the suctioning connection channel 3, thus forming cone walls 40.

(55) The sweeper roller 16 is attached to a shaft which is rotatingly driven by a rotary drive (not depicted).

(56) FIG. 5 shows that the receiving space 76 for the operation of the sweeper roller 14 is closed off in the housing 26 by a sealing wall 38 in the rear, and then continues as cone wall 44 facing obliquely toward the rear.

(57) Preferably, however, the fine dirt 18 input into the dirt collection device 2 by the sweeper roller is transported during normal operation in arrow direction 47 and not deposited in the intermediate container 10.

(58) FIGS. 6 and 7 show the application of the invention principle on a vacuum cleaner nozzle 60, wherein the description for the dirt collecting device 2 according to FIGS. 1 to 5 similarly applies to the vacuum cleaner nozzle 60.

(59) The vacuum cleaner nozzle 60 shown in the embodiment of FIGS. 6 and 7 refers to an upright vacuum cleaner described, e.g. in U.S. Pat. No. 5,500,979 A1.

(60) The vacuum cleaner nozzle 60 essentially consists of a housing 63, which is closed on all sides, having a rear wall 66 and adjacent side walls 67, wherein the front side of the vacuum cleaner nozzle is closed by means of a front wall 78.

(61) The upper side of the vacuum cleaner nozzle 60 is formed by a closed cover wall 68.

(62) In the front area of the vacuum cleaner nozzle, a brush roller 61 is arranged in the housing 63, said brush roller 61 being driven rotatingly. The brush roller 61 runs essentially perpendicularly to the longitudinal axis through the vacuum cleaner nozzle 60 and is covered with individual brushes 74.

(63) According to FIG. 7, the brush roller 61 operates in a receiving space 76 which is open toward the bottom in the direction of a carpet pile 73. Of course, the carpet pile can be substituted with a hard floor surface.

(64) Therefore, the suction pressure, which is applied by a suction fan (not depicted; see U.S. Pat. No. 5,500,979 A1) and introduced into the housing 63 by means of the connection channel 3, acts into the receiving space 76.

(65) The rotatingly driven brushes 74 therein comb out the hard surface to be cleaned or the carpet pile 73 and convey the accumulated coarse and fine dirt 17, 18 according to the throw-over principle over the brush roller 61 into a downstream intermediate container 70.

(66) The depicted vacuum cleaner nozzle 60 is thus also designed as a dirt collecting device 62 in the same manner as was described using FIGS. 1 to 5 and essentially consists of the rotatingly driven brush roller 61 which conveys the coarse and fine dirt input into in the receiving space 76 toward the rear in the housing into an intermediate container 70. The rotary drive of the brush roller 61 is shown in FIG. 6. For this purpose, a motor is used that drives a belt drive 69 by means of its driveshaft 65, said belt drive 69 running over the brush roller 61 and driving it rotatingly.

(67) A shaft 72 is associated with the belt drive 69.

(68) The intermediate container 70 is formed by a floor surface 71 which is divided toward the front by means of an end wall 77. Even though it is not shown in the drawing, it is provided that the end wall 77 is slightly elevated as was described with regard to the cone wall 44 in FIGS. 4 and 5 of the aforementioned embodiment.

(69) Therefore, the intermediate container 70 is designed so as to be trough-shaped and open toward the top, and is provided particularly for receiving coarse dirt 17. In case of vacuum cleaner nozzles 60 of the initially described type, such coarse dirt are, e.g. small pebbles or other non-dispersible objects which cannot be conveyed to the downstream collection container with the low suction pressure applied. Therefore, at the reduced suction pressure during normal operation, they are deposited in the intermediate container 70, and the filling level in the intermediate container 70 is monitored by a filling level sensor 49.

(70) Once the filling level in the intermediate container 70 has reached a specific filling height, the suction power of the suction fan is increased by two or three times the power applied during normal operation in order to convey the coarse dirt parts deposited in the intermediate container 70 in arrow direction 21 to a downstream collection container (not depicted) on the side of the final storage by means of the connection channel 30.

(71) It is once again provided that even if the low negative pressure present during normal operation is applied, the negative pressure is selected such that the input fine dirt 18 is always conveyed in arrow direction 21 into the downstream collection container (not depicted).

(72) The intermediate container 70 is thus essentially only intended for the intermediate storage of the input coarse dirt 17 which is conveyed by the brush roller 61 in arrow direction 43 into the intermediate container 70.

(73) FIG. 8 shows schematically that the filling level is monitored by the filling level sensor 49 in the intermediate container 10, 70, and when the filling level exceeds a maximum height, a sensor signal 52 is generated in a time period between t1 and t2.

(74) Normal operation takes place in the time period of 0 to t1 and also between t2 and t3.

(75) The time periods for the normal operation between 0 and t1 and t2 and t2 are shown only in a shortened form. In reality, these are time periods which temporally are significantly more drawn out, which is shown with the formulas entered in the drawings. The operating time during normal operation is t.sub.B, while the operating time during cleaning operation is t.sub.C.

(76) FIG. 9 shows that, on the basis of the sensor signal 52 according to FIG. 8, the air speed of a suction fan 8 in a dirt collecting device 2 for a sweeping vehicle 1 is increased from a normal operation of 260 l/s to, e.g. 560 l/s. During this time, the coarse dirt 17 from the intermediate container 10 becomes dispersible and is removed, and once the filling level sensor 49 has indicated the emptying of the intermediate container 10, the switch back to normal operation with reduced suction pressure takes place at the time t2.

(77) In the time period between t3 and t4, a further cleaning or emptying cycle of coarse dirt 17 from the intermediate container 10 takes place.

(78) FIG. 10 shows that due to the increase in the suction pressure in FIG. 5 in emptying mode, the power of the suction fan of approximately 1180 watts (normal operation) must be increased to approximately 3950 watts in order to reach a sufficiently high air speed in the time period between t1 and t2 as well as in the time period between t3 and t4. The dotted line shows the mean energy consumption averaged therefrom.

(79) When compared to the prior art, it is important that in the prior art in FIG. 10, there is a constant maximum energy consumption of the suction fan of 3950 watts, and it is not provided that the energy consumption of the fan is reduced to 1180 watts during normal operation.

(80) It is self-evident that the consumption figures of the energy consumption used herein can vary to a great extent and depend on the power of the suction fan. It is only of importance that during normal operation, the suction fan operates only at a third of the maximum power and that this normal operation is maintained for a very long period of time until the intermediate container 10 is completely filled with coarse dirt 17 and the filling level sensor 49 signals said maximum filling level.

(81) Analogously, FIG. 11 shows the energy consumption of a suction fan for a vacuum cleaner nozzle 60, also indicating that in the time period between 0 and t1, the suction fan only requires energy of 250 watts, and the suction power is increased to a value of 900 watts only for the emptying of the intermediate container 70 from coarse dirt 17.

(82) It is once again self-evident that the watt figures must be understood to be examples because the ratio between the minimum energy consumption and the maximum energy consumption of the suction fan used is of greater importance.

(83) Accordingly, FIG. 12 in conjunction with FIG. 11 also shows that during normal operation, a suction airflow of, e.g. 10 l/s is present only in the area of the suction nozzle, while the suction airflow is increased to 40 l/s in emptying mode.

(84) FIG. 13 shows that for a sweeping vehicle 1 having a dirt collecting device 2, the suction fan 8 used must be operated with a maximum energy of e.g. 3700 watts for merely, e.g. 10% of the operating time, and is operated for almost 100% of the operating time only at an energy consumption of 1100 watts.

(85) The depicted consumption curve 53 must be understood to be a mere example, and the value figures indicated are only used as an example to illustrate the invention.

(86) The table in FIG. 14 shows that in emptying mode, the suction fan shows an energy consumption of 3269 watts, while during normal operation, the fan only shows an energy consumption of 480 watts, while the brush power of the sweeper roller 14 lies constantly at 700 watts of electrical power.

(87) Therefore, at its peak, an energy consumption of 3969 watts is indicated for the emptying mode, while during normal operation, the suction fan consumes energy of merely 1180 watts.

(88) The table in FIG. 15 shows the time portion of the energy consumption of the suction fan for the dirt collecting device 2 of a sweeping vehicle 1 on the basis of the operating time used. It can be seen that the sweeping vehicle is predominantly operated with a suction fan of reduced power (90% time portion at 1459 watts), and only an emptying time of 10% of the operating time is burdened with an energy consumption of 3690 watts.

REFERENCE SIGNS

(89) 1 Sweeping vehicle 2 Dirt collecting device 3 Connection channel 4 Coarse dirt collection container 5 Connection channel 6 Fine dirt collection container 7 Filter 8 Suction fan 9 Motor 10 Intermediate container 11 Drive shaft 12 Arrow direction 13 Arrow direction 14 Sweeper roller 15 Front spoiler 16 Rack frame 17 Coarse dirt 18 Fine dirt 19 Roadway plane 20 Arrow direction 21 Arrow direction 22 Arrow direction 23 Arrow direction 24 Arrow direction 25 Arrow direction 26 Housing 27 Cover wall 28 Side wall 29 Rear wall 30 Support and drive unit 31 Roller 32 Arrow direction 33 Pivot axis 34 Arrow direction 35 Sealing lip 36 Arrow direction 37 Side spoiler (from 15) 38 Front wall 39 Cone narrowing 40 Cone wall (from 10) 41 Floor surface (from 10) 42 Shaft (from 10) 43 Arrow direction 44 Cone wall (from 10) 45 Settling wall (from 10) 46 Arrow direction 47 Arrow direction 48 Sealing wall 49 Filling level sensor 49′ 50 Measuring beam 51 Filling level 52 Sensor signal 53 Consumption curve 54 - 55 - 56 - 57 - 58 - 59 - 60 Vacuum cleaner nozzle 61 Brush roller 62 Dirt collecting device 63 Housing 64 Motor 65 Drive shaft 66 Rear wall 67 Side wall 68 Cover wall 69 Belt drive 70 Intermediate container 71 Floor surface 72 Shaft 73 Carpet pile 74 Brush (from 61) 75 Rotational axis 76 Receiving space (for brush roller) 77 End wall 78 Front wall