DE102022128567A1 - SURFACE CLEANING HEAD - Google Patents

Abstract

The invention relates to a surface cleaning head for cleaning a surface (11), with a hood-shaped housing (12) which is open downwards in a horizontal position of use of the surface cleaning head (10), in which at least one spray arm (40, 42) with a cleaning nozzle (44, 46) is mounted so as to be rotatable about an axis of rotation (32), wherein the cleaning nozzle (44, 46) can be supplied with pressurized cleaning liquid and the cleaning nozzle (44, 46) rotates together with the spray arm (40, 42) about the axis of rotation (32) to apply a jet of liquid to the surface (11) to be cleaned. In order to further develop the surface cleaning head in such a way that it has a higher cleaning performance, it is proposed that the surface cleaning head has an oscillation device (50; 212; 246; 272; 282; 302) for generating temporal and/or spatial oscillations of the liquid jet emitted by the cleaning nozzle.

Description

The invention relates to a surface cleaning head for cleaning a surface, with a hood-shaped housing which is open downwards in a horizontal position of use of the surface cleaning head and in which at least one spray arm with a cleaning nozzle is mounted so as to be rotatable about an axis of rotation, wherein pressurized cleaning liquid can be supplied to the cleaning nozzle and the cleaning nozzle rotates together with the spray arm about the axis of rotation to apply a jet of liquid to the surface to be cleaned.

Such surface cleaning heads are from the EN 10 2007 029 245 A1 They are particularly suitable for cleaning hard surfaces, for example stone or wooden terraces, garage entrances and garage doors. To clean the surfaces, the pressure line of a high-pressure cleaning device can be connected to the surface cleaning head. Pressurized cleaning fluid, in particular water, can be supplied to the surface cleaning head via the pressure line. The surface cleaning head has at least one spray arm which is mounted so as to rotate about an axis of rotation and which carries a cleaning nozzle. The pressurized cleaning fluid can be fed to the cleaning nozzle. The cleaning nozzle can be used to spray a jet of fluid onto the surface to be cleaned, with the at least one spray arm rotating around the axis of rotation together with the cleaning nozzle attached to it. Usually at least two or three spray arms are used, each of which carries a cleaning nozzle, with all of the cleaning nozzles being able to be supplied with pressurized cleaning fluid at the same time and the cleaning nozzles performing a circular movement around the axis of rotation.

Such surface cleaning heads have proven themselves. However, it is desirable to increase the cleaning performance of the surface cleaning heads.

The object of the invention is therefore to further develop a surface cleaning head of the type mentioned at the beginning in such a way that it has a higher cleaning performance.

This object is achieved according to the invention in a surface cleaning head of the generic type in that the surface cleaning head has an oscillation device for generating temporal and/or spatial oscillations of the liquid jet.

The oscillation device can be used to generate a liquid jet that oscillates in time and/or space and can be directed at the surface to be cleaned. The oscillations of the liquid jet cause the liquid jet emerging from the cleaning nozzle to disintegrate, so that it at least partially breaks down into individual liquid droplets on the way from the cleaning nozzle to the surface to be cleaned, and individual droplets then hit the surface to be cleaned. This leads to a so-called water hammer effect, which increases the impact force of the liquid, which significantly increases the cleaning performance. The high impact force of the droplets means that even stubborn dirt can be removed from the surface to be cleaned without the need for subsequent treatment of the surface. The increased cleaning performance also has the advantage that the surface cleaning head can be moved along the surface to be cleaned at a higher speed and that cleaning liquid and energy can be saved when cleaning the surface.

The liquid jet emitted by the cleaning nozzle attached to a spray arm not only performs a circular movement around the rotation axis of the spray arm, but also exhibits temporal and/or spatial oscillations, under the effect of which the liquid jet emitted by the cleaning nozzle is at least partially broken down into individual drops. The individual liquid drops do not necessarily have to be completely separated from one another; it can also be provided that the drops are connected to one another via narrow liquid bridges (liquid ligaments), so that the liquid jet forms a modulated or pulsed liquid flow.

The temporal oscillations can be, for example, pressure fluctuations in the flow direction of the liquid jet. The spatial oscillations can be, for example, an additional pendulum movement of the liquid jet. The pendulum movement is preferably aligned transversely to the circular movement of the liquid jet around the axis of rotation.

In the case of spatial oscillation of the liquid jet, the oscillation frequency is preferably at least 10 Hz, in particular 10 Hz to 3,000 Hz.

In the case of a temporal oscillation of the liquid jet, the oscillation frequency is preferably 10 kHz to 30 kHz, in particular 20 kHz to 25 kHz.

The rotational speed of the at least one spray arm is preferably a maximum of 15,000 revolutions per minute, in particular 1,000 to 3,000 revolutions per minute, for example 1,500 to 2,000 revolutions per minute.

In a preferred embodiment of the invention, the oscillation frequency of the liquid jet is at least as high as the rotational speed of the at least one spray arm.

It is particularly advantageous if the oscillation frequency of the liquid jet is a multiple of the rotational speed of the at least one spray arm. In such a configuration, the liquid jet emitted by the cleaning nozzle performs a large number of oscillations during one rotation of the spray arm about the axis of rotation, which result in the liquid jet disintegrating by dissolving at least partially into individual liquid drops.

In a preferred embodiment of the surface cleaning head according to the invention, the oscillation device is integrated into the cleaning nozzle arranged on the at least one spray arm. This enables a particularly compact design of the surface cleaning head.

It is advantageous if the cleaning nozzle has a through-channel and the oscillation device forms a flow chamber in the through-channel in which a flow guide element is arranged to generate a spatial oscillation of the liquid jet emitted by the cleaning nozzle. With the help of the flow guide element, the cleaning liquid flowing through the through-channel of the cleaning nozzle can be given a pendulum movement transverse to the longitudinal axis of the through-channel, so that the liquid jet emerging from the cleaning nozzle performs a pendulum movement in addition to its circular movement around the axis of rotation of the spray arm. This allows the liquid jet to be at least partially broken down into individual drops that hit the surface to be cleaned with high impact force.

In a preferred embodiment of the invention, the flow guide element divides the flow chamber of the cleaning nozzle into a central flow channel and two feedback channels located opposite one another, the feedback channels connecting an output section of the central flow channel to an input section of the central flow channel. The pressurized cleaning fluid can flow through the central flow channel, with part of the cleaning fluid being returned via the feedback channels from the output section of the central flow channel to its input section. The mouth areas of the feedback channels in the input section of the central flow channel are preferably located opposite one another, so that the cleaning fluid flows returned via the feedback channels meet in the input section of the central flow channel and, due to flow instabilities, stimulate the cleaning fluid flowing through the central flow channel to lateral deflections that are directed in succession and in opposite directions. A resonance oscillation is thus induced in the central flow channel, which results in the liquid jet emerging from the cleaning nozzle, in addition to its circular movement around the axis of rotation of the spray arm, performing a pendulum movement under the effect of which it at least partially disintegrates into individual droplets.

Preferably, the central flow channel has an inlet section, which is successively followed by a first lens-shaped section and a second lens-shaped section, wherein the first lens-shaped section is longer than the second lens-shaped section and the second lens-shaped section forms the outlet section of the central flow channel.

Preferably, the length of the first lens-shaped portion is at least 1.3 times the length of the second lens-shaped portion.

A flow separation edge is preferably arranged between the first lens-shaped section and the second lens-shaped section.

In an advantageous embodiment of the surface cleaning head according to the invention, the oscillation device is designed as a pulsation device for generating temporal oscillations in the form of pressure fluctuations in the liquid jet that is emitted by the cleaning nozzle held on a spray arm. The pressure fluctuations lead to a partial or complete dissolution of the liquid jet into individual drops at a short distance from the cleaning nozzle, which impact the surface to be cleaned with high impact force under the effect of the water hammer effect.

It is advantageous if the cleaning fluid can be subjected to pressure pulses by means of the pulsation device.

In an advantageous embodiment of the surface cleaning head according to the invention, the pulsation device has a resonator chamber which forms a pressure resonator for applying pressure pulses to the cleaning liquid. The resonator chamber can be designed, for example, in the form of a Helmholtz resonator. In particular, it can be provided that axially aligned pressure fluctuations can be achieved in the cleaning liquid with respect to its flow direction by means of the resonator chamber.

The resonator chamber can, for example, form a cylindrical cavity with an inlet opening and an outlet opening through which the cleaning fluid can flow. In such a design, the inlet opening of the cavity is followed by a step that is directed radially outwards in relation to the flow direction of the cleaning fluid, at which the flow of the cleaning fluid separates so that vortices are formed that move within the cylindrical cavity in the flow direction, with a resonance vibration forming in the cavity, which results in axially aligned pressure fluctuations in the cleaning fluid.

The resonator chamber can be integrated into the cleaning nozzle.

Alternatively, it can be provided that the cleaning fluid that can be fed to the cleaning nozzle can flow through the resonator chamber. In such an embodiment of the invention, the resonator chamber is arranged upstream of the cleaning nozzle.

For example, it can be provided that the resonator chamber is arranged in the at least one spray arm.

In particular, it can be provided that the resonator chamber is arranged directly upstream of the cleaning nozzle. In such an embodiment of the invention, the at least one spray arm has a region to which the cleaning nozzle is connected and in which the resonator chamber is arranged.

It can also be provided that the resonator chamber is arranged upstream of the at least one spray arm.

In an advantageous embodiment of the invention, the pulsation device has at least one piezoceramic part to which an alternating electrical voltage can be applied, wherein the cleaning liquid can be subjected to pressure pulses by the at least one piezoceramic part. The application of the alternating electrical voltage to the at least one piezoceramic part results in a periodic expansion and contraction of the at least one piezoceramic part, so that the cleaning liquid contacting the at least one piezoceramic part is subjected to pressure pulses that cause pressure fluctuations in the cleaning liquid. The pressure fluctuations lead to a disintegration of the liquid jet emerging from the cleaning nozzle.

It is advantageous if at least one piezoceramic part has a passage through which the cleaning fluid can flow. Due to the application of the alternating electrical voltage to the piezoceramic part, the flow cross-section of the passage changes periodically. By reducing and increasing the flow cross-section, pressure pulses are exerted on the cleaning fluid flowing through the passage, which result in pressure fluctuations spreading in the direction of flow of the cleaning fluid and cause disintegration of the cleaning fluid emerging from the cleaning nozzle.

It is particularly advantageous if the pulsation device has a first and a second piezoceramic part, the first piezoceramic part having a passage channel in which the second piezoceramic part is arranged to form an annular gap, the annular gap through which the cleaning fluid can flow. With such a design, the cleaning fluid can be subjected to pressure pulses from both the first piezoceramic part and the second piezoceramic part. The cleaning fluid flows around the second piezoceramic part arranged in the passage channel of the first piezoceramic part, so that very strong pressure fluctuations form in the cleaning fluid, which result in disintegration of the fluid jet emerging from the cleaning nozzle.

Alternatively or additionally, the pulsation device can have at least one piezoceramic part that is cuboid-shaped or cylindrical and has a pressure application surface on one end face for applying pressure pulses to the cleaning fluid. The cuboid-shaped or cylindrical piezoceramic part can form a type of piston that has a pressure application surface, wherein the pressure application surface is excited to mechanical vibrations due to the application of the alternating electrical voltage to the piezoceramic part. The cleaning fluid can flow along the pressure application surface and be subjected to pressure pulses by it.

The electrical alternating voltage can be provided by means of external control electronics, which can be connected to the surface cleaning head via an electrical connecting cable.

It is particularly advantageous if the surface cleaning head has a battery-operated alternating voltage generator for applying an electrical alternating voltage to the at least one piezoceramic part. With such a design of the surface cleaning head according to the invention, an electrical connection to external control electronics can be omitted.

In an advantageous embodiment, the surface cleaning head according to the invention has an inlet channel for the pressurized cleaning fluid upstream of the at least one spray arm, wherein the cleaning fluid in the region of the inlet channel can be subjected to pressure pulses by means of the pulsation device. In such an embodiment of the invention, the pressurized cleaning fluid provided to the surface cleaning head is subjected to pressure pulses upstream of the at least one spray arm.

For example, it can be provided that the inlet channel has at least one radial extension in which at least one piezoceramic part to which an alternating electrical voltage can be applied is arranged or which forms a resonator chamber, wherein the resonator chamber can be flowed through by the pressurized cleaning fluid.

The cleaning nozzle held on a spray arm experiences a recoil when the liquid jet is released. It can be provided that the spray arm is set in rotation about the axis of rotation under the effect of the recoil. In this case, it is advantageous if the orientation of the cleaning nozzle in the direction of the surface to be cleaned is adjustable. This allows the inclination of the cleaning nozzle, which it assumes in a horizontal position of use of the surface cleaning head relative to the vertical, to be changed. The more the cleaning nozzle is inclined to the vertical, the greater the horizontal force component of the recoil that is exerted by the cleaning nozzle on the associated spray arm when the liquid jet is released. This in turn leads to a stronger acceleration of the spray arm, i.e. to a higher speed of the spray arm. The high cleaning performance that can be achieved by means of the surface cleaning head according to the invention allows the surface cleaning head to be moved along the surface to be cleaned at a relatively high speed. In this case, the at least one spray arm should have a relatively high speed. A high speed can be achieved easily by a relatively strong inclination of the cleaning nozzle attached to the spray arm relative to the vertical. However, if the surface to be cleaned has very stubborn dirt, the inclination of the cleaning nozzle relative to the vertical can be reduced if necessary in order to also reduce the speed of at least one spray arm.

For example, it can be provided that the at least one spray arm has an inner and an outer spray arm section relative to the rotation axis, wherein the cleaning nozzle is held on the outer spray arm section and the outer spray arm section can be detachably connected to the inner spray arm section in different rotational positions relative to the longitudinal axis of the spray arm. Depending on the rotational position that the outer spray arm section has relative to the inner spray arm section, the cleaning nozzle held on the outer spray arm section has a different inclination to the vertical, so that the entire spray arm has a speed that depends on the rotational position of the outer spray arm section.

In order to increase the speed of the at least one spray arm, it can be provided that an additional nozzle for dispensing cleaning fluid is arranged on the at least one spray arm and is aligned tangentially with respect to the direction of rotation of the spray arm. The tangential alignment of the additional nozzle exerts a recoil on the spray arm, which leads to an acceleration of the spray arm so that it rotates around the axis of rotation at high speed. The additional nozzle can have a significantly smaller nozzle opening than the cleaning nozzle held on the spray arm, so that the flow rate of the cleaning fluid dispensed via the additional nozzle can be kept low and a considerable recoil can still be exerted on the spray arm.

The rotational drive of the at least one spray arm can also be carried out using a turbine wheel. For this purpose, in an advantageous embodiment, the surface cleaning head according to the invention has a turbine wheel that is connected in a rotationally fixed manner to the at least one spray arm and that can be acted upon by the cleaning liquid that can be fed to the cleaning nozzle. Under the effect of the pressurized cleaning liquid that acts on the turbine wheel, the turbine wheel and with it the at least one spray arm are set in rotation about the axis of rotation.

It can also be provided that the surface cleaning head has a motorized rotary drive, wherein the at least one spray arm can be set in rotation about the axis of rotation by means of the rotary drive.

It is advantageous if the surface cleaning head has a battery, in particular a rechargeable battery, to supply energy to the rotary drive.

In an advantageous embodiment of the surface cleaning head, the rotation axis of the at least one spray arm is inclined to the vertical in a horizontal position of use of the surface cleaning head. In such an embodiment, the at least one spray arm rotates in a rotation plane that is aligned at an angle to the horizontal. This means that the cleaning nozzle arranged on the spray arm changes its distance from the surface to be cleaned during a circular movement around the rotation axis, so that the disintegration of the liquid jet emitted by the cleaning nozzle takes place at different distances from the surface to be cleaned and thus the liquid jet at least partially dissolves into individual drops at different distances from the surface to be cleaned.

• 1: eine vertikale Schnittansicht einer ersten Ausführungsform eines Flächenreinigungskopfs;
• 2: eine vergrößerte Darstellung von Detail X aus 1;
• 3: eine Unteransicht des Flächenreinigungskopfs aus 1;
• 4: eine vertikale Schnittansicht einer zweiten Ausführungsform eines Flächenreinigungskopfs;
• 5: eine perspektivische Darstellung des Flächenreinigungskopfs aus 4 schräg von unten;
• 6: eine vertikale Schnittansicht einer dritten Ausführungsform eines Flächenreinigungskopfs;
• 7: eine vertikale Schnittansicht einer vierten Ausführungsform eines Flächenreinigungskopfs;
• 8: eine Unteransicht des Flächenreinigungskopfs aus 7;
• 9: eine vertikale Schnittansicht einer fünften Ausführungsform eines Flächenreinigungskopfs;
• 10: eine vertikale Schnittansicht einer sechsten Ausführungsform eines Flächenreinigungskopfs;
• 11: eine vertikale Schnittansicht einer siebten Ausführungsform eines Flächenreinigungskopfs;
• 12: eine vertikale Schnittansicht einer achten Ausführungsform eines Flächenreinigungskopfs;
• 13: eine vertikale Schnittansicht einer neunten Ausführungsform eines Flächenreinigungskopfs;
• 14: eine vertikale Schnittansicht einer zehnten Ausführungsform eines Flächenreinigungskopfs;
• 15: eine vertikale Schnittansicht einer elften Ausführungsform eines Flächenreinigungskopfs.

The following description of advantageous embodiments of the invention serves to explain in more detail in conjunction with the drawing. They show:

• 1 : a vertical sectional view of a first embodiment of a surface cleaning head;
• 2 : an enlarged view of detail X from 1 ;
• 3 : a bottom view of the surface cleaning head from 1 ;
• 4 : a vertical sectional view of a second embodiment of a surface cleaning head;
• 5 : a perspective view of the surface cleaning head from 4 obliquely from below;
• 6 : a vertical sectional view of a third embodiment of a surface cleaning head;
• 7 : a vertical sectional view of a fourth embodiment of a surface cleaning head;
• 8th : a bottom view of the surface cleaning head from 7 ;
• 9 : a vertical sectional view of a fifth embodiment of a surface cleaning head;
• 10 : a vertical sectional view of a sixth embodiment of a surface cleaning head;
• 11 : a vertical sectional view of a seventh embodiment of a surface cleaning head;
• 12 : a vertical sectional view of an eighth embodiment of a surface cleaning head;
• 13 : a vertical sectional view of a ninth embodiment of a surface cleaning head;
• 14 : a vertical sectional view of a tenth embodiment of a surface cleaning head;
• 15 : a vertical sectional view of an eleventh embodiment of a surface cleaning head.

In the 1 , 2 and 3 a first advantageous embodiment of a surface cleaning head according to the invention is shown schematically. The surface cleaning head is designated overall by the reference number 10 and has a hood-shaped housing 12 which, in the horizontal position of use shown, is open downwards in the direction of a surface 11 to be cleaned and has a top wall 14 from which a circular, self-contained side wall 16 projects downwards, which has a circumferential splash guard element 20 on its free edge 18. The splash guard element 20 can be designed, for example, in the form of a bristle strip.

The top wall 14 has a central opening 22 through which a connecting part 24 passes. The connecting part 24 forms an inlet channel 26, to the end 28 of which facing away from the housing 12 a pressure line of a high-pressure cleaning device can be connected, which is known per se and is not shown in the drawing for the sake of clarity. The pressure line can be used to provide the surface cleaning head 10 with cleaning fluid that has been pressurized by the high-pressure cleaning device.

In the connecting part 24, a tubular connecting part 30 is mounted so as to be rotatable about a rotation axis 32 which is vertically aligned in the horizontal position of use of the surface cleaning head 10 shown. For the rotatable mounting of the connecting part in the connecting part 24, bearing elements are used which are in the form of a first ball bearing ring 34 and a second ball bearing ring 36.

The connecting part 30 has an end section 38 which projects downwards from the connecting part 24 in the direction facing away from the inlet channel 26 and on which two diametrically opposed spray arms 40, 42 are held in a rotationally fixed manner. At their free ends, the two spray arms 40, 42 each carry a cleaning nozzle 44 or 46, which can be rotated together with the spray arms 40, 42 about the rotation axis 32.

By means of the cleaning nozzles 44, 46, a liquid jet can be directed onto a surface 11 to be cleaned in order to clean the surface 11. To clean the surface 11, the surface cleaning head 10 can be moved along the surface 11, wherein it can be supported on the surface 11 by means of the splash guard element 20.

The cleaning nozzles 44, 46 generate a liquid jet directed obliquely downwards. For this purpose, they are aligned obliquely to the vertical in the horizontal position of use of the surface cleaning head 10 shown. This is particularly evident from 3 When exiting the cleaning nozzles 44, 46, the liquid jets directed diagonally downwards generate a recoil which exerts a torque on the spray arms 40, 42 and thereby causes them to rotate about the axis of rotation 32.

In order to increase the cleaning performance, an oscillation device 50 is integrated into each of the cleaning nozzles 44, 46 to generate spatial oscillations of the liquid jets emitted by the cleaning nozzles 44, 46 in the form of a pendulum movement, which is superimposed on the circular movement of the liquid jets around the axis of rotation 32 and in the 1 and 2 is illustrated by a dashed line 52. The spatial oscillations provoke a disintegration of the liquid jets emerging from the cleaning nozzles 44, 46, so that the liquid jets at least partially dissolve into individual liquid droplets at a short distance from the cleaning nozzles 44, 46. Due to the water hammer effect, the individual droplets hit the surface 11 to be cleaned with high impact force, so that the surface 11 to be cleaned can be cleaned with high cleaning performance. The high cleaning performance allows the surface cleaning head 10 to be guided at a relatively high speed along the surface 11 to be cleaned, whereby even stubborn dirt, for example lichen, can be removed from the surface 11 to be cleaned without complex subsequent cleaning. The high cleaning performance also makes it possible to save cleaning fluid and energy while maintaining the same cleaning performance compared to known surface cleaning heads.

The cleaning nozzles 44, 46 are identically designed and each have an oscillation device 50 which is 2 is shown enlarged using the example of the cleaning nozzle 44. The cleaning nozzle 44 has a through-channel 54 which extends from a nozzle inlet 56 facing the spray arm 40 to a nozzle outlet 58 facing away from the spray arm 40. The oscillation device 50 forms a flow chamber 60 in the through-channel 54, in which a flow guide element 62 is arranged. The flow guide element 62 divides the flow chamber 60 into a central flow channel 64 and two mutually opposite feedback channels 66, 68 which connect an output section 70 of the central flow channel 64 to an input section 72 of the central flow channel 64. The central flow channel 64 has, downstream of the inlet section 72, a first section 74 which is lens-shaped in a longitudinal section and a second section 76 which is lens-shaped in the longitudinal section and which is immediately adjacent to this, wherein a flow separation edge 78 is arranged between the first lens-shaped section 74 and the second lens-shaped section 76 and the second lens-shaped section 76 forms the outlet section 70 of the central flow channel 74 from which the feedback channels 66, 68 originate. The first lens-shaped section 74 is longer than the second lens-shaped section 76. In the exemplary embodiment shown, the length of the first lens-shaped section 74 is approximately 1.5 times the length of the second lens-shaped section 76.

The cleaning liquid entering the through-channel 54 of the cleaning nozzle 44 can flow through the central flow channel 64, with a portion of the cleaning liquid being returned from the outlet section 70 to the inlet section 72 via the feedback channels 66, 68. The mouth areas of the feedback channels 66, 68 are located directly opposite one another, so that the liquid flows returned via the feedback channels 66, 68 meet in the inlet section 72 and, due to flow instabilities, excite the cleaning liquid flowing through the central flow channel 64 to lateral deflections that are directed in succession and in opposite directions. This results in a self-excited resonance oscillation forming in the central flow channel 64, so that the liquid exiting from the cleaning nozzle 44 In addition to its circular movement around the axis of rotation 32, the jet carries out the aforementioned pendulum movement 52, under the effect of which the liquid jet disintegrates into individual drops. The individual drops hit the surface 11 to be cleaned. This leads to a so-called water hammer effect, which leads to an increased impact force of the cleaning liquid, which significantly increases the cleaning performance. The drops can be completely separated from one another or connected to one another via narrow liquid bridges (liquid ligaments), so that the liquid jet forms a modulated or pulsed liquid flow.

The oscillation frequency of the liquid jets emitted by the cleaning nozzles 44, 46 is preferably at least 10 Hz, in particular 10 Hz to 3,000 Hz.

The rotational speed of the spray arms 40, 42 is preferably a maximum of 15,000 revolutions per minute, in particular 1,000 to 3,000 revolutions per minute, for example 1,500 to 2,000 revolutions per minute.

In the 4 and 5 A second advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 80. The surface cleaning head 80 is, like the one described below with reference to the 6 to 15 explained advantageous embodiments of surface cleaning heads according to the invention are designed largely identically to the 1 , 2 and 3 shown and explained above surface cleaning head 10. In the 4 and 5 and also in the 6 to 15 Therefore, identical components are given the same reference symbols as in the 1 , 2 and 3 , and with regard to these components, reference is made to the preceding explanations in order to avoid repetition.

The one in the 4 and 5 The schematically illustrated surface cleaning head 80 differs from the one shown in the 1 and 2 schematically illustrated surface cleaning head 10 in that the alignment of the cleaning nozzles 44, 46 relative to the surface 11 to be cleaned is adjustable. For this purpose, the surface cleaning head 80 has two diametrically opposed spray arms 82, 84, which each have an inner spray arm section 86 or 88 and an outer spray arm section 90 or 92 with respect to the rotation axis 32. The inner spray arm sections 86, 88 each have a first ring flange 94 or 96, and the outer spray arm sections 90, 92 each have a second ring flange 98, 100, wherein a second ring flange 98, 100 can be detachably screwed to a first ring flange 94 or 96 with the interposition of a sealing ring (not shown in the drawing for the sake of clarity). The first ring flanges 94, 96, like the second ring flanges 98, 100, have a plurality of through holes 106, 108 arranged at a uniform angular distance from one another with respect to the longitudinal axes 102, 104 of the two spray arms 82, 84. This allows the outer spray arm sections 90, 92 to be screwed to the inner spray arm sections 86, 88 in a desired rotational position, with a through hole 106 of the first ring flanges 94, 96 being aligned with a through hole 108 of the second ring flange 98, 100, so that a connecting screw can be guided through the through holes 106, 108 which are aligned with one another. In this way, the outer spray arm sections 90, 92 can assume a desired rotational position relative to the longitudinal axes 102, 104, and as a result, the cleaning nozzles 44, 46 can assume a desired orientation relative to the surface 11 to be cleaned. In the illustrated position of use of the surface cleaning head 80, the cleaning nozzles 44, 46 can have a smaller or a larger inclination to the vertical. The greater the inclination to the vertical, the greater the horizontal directional component of the recoil that acts on the cleaning nozzles 44, 46 when the cleaning liquid is dispensed and drives the spray arms 82, 84 to rotate about the axis of rotation 32. By changing the rotational position of the outer spray arm sections 90, 92, the speed of the spray arms 40, 42 can thus be changed.

In 6 A third advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 120 and differs from the one shown in the 4 and 5 shown surface cleaning head 80 by spray arms 122, 124, the axis of rotation 126 of which is inclined to the vertical in the horizontal position of use shown. This means that the distances that the cleaning nozzles 44, 46 assume from the surface 11 to be cleaned change continuously during a circular movement of the spray arms 122, 124 about the axis of rotation 126. This in turn means that the distances of the drops formed due to the disintegration of the liquid jets change continuously during a circular movement of the spray arms 122, 124. As a result, the drops striking the surface 11 to be cleaned can have a different size and/or a different impact force and, with a shorter distance, can be at least partially connected to one another via narrow liquid bridges (liquid ligaments). This supports high cleaning performance, for example on uneven surfaces.

In the 7 and 8th a fourth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 140. The surface cleaning head 140 differs from the surface cleaning head 80 explained above by spray arms 142, 144, each of which has an additional nozzle 146, 148, which are arranged upstream of the cleaning nozzles 44, 46 and are aligned tangentially with respect to the direction of rotation of the spray arms 142, 144. A tangentially aligned liquid jet can be emitted via the additional nozzles 146, 148, which exerts a recoil on the respective spray arm 142, 144 in order to increase the speed of the spray arms 142, 144. The nozzle openings of the additional nozzles 146, 148 can be considerably smaller than the nozzle openings of the cleaning nozzles 44, 46 in order to keep the flow rate of the cleaning fluid delivered via the additional nozzles 146, 148 low.

The use of the additional nozzles 146, 148 makes it possible, in a structurally simple manner, to increase the speed of the spray arms 142, 144 rotating around the rotation axis 32. This in turn makes it possible to guide the surface cleaning head 140 at a relatively high speed along the surface 11 to be cleaned. Due to the high cleaning performance that can be achieved by means of the oscillation devices 50, the relatively high speed of the surface cleaning head 140 does not impair the cleaning result.

In 9 a fifth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 160. The surface cleaning head 160 has diametrically opposed spray arms 162, 164, which can be set in rotation about the axis of rotation 32 by means of an electric motor rotary drive 166. The rotary drive 166 comprises an electric motor 168, which is coupled to the connecting part 30 via a gear 170 and which is supplied with electrical energy by a rechargeable battery 172 and controlled by a control device 174. The battery 172 can be connected to an external charger via a charging socket 176.

In 10 a sixth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 190. The surface cleaning head 190 has two diametrically opposed spray arms 192, 194, which are connected in a rotationally fixed manner to a turbine wheel 196. The turbine wheel 196 can be supplied with the cleaning liquid that can be fed to the cleaning nozzles 44, 46 and is set in rotation by the cleaning liquid about the rotation axis 32 of the spray arms 192, 194. With such a design, it is not necessary for the cleaning nozzles 44, 46 to be inclined obliquely to the vertical in a horizontal position of use of the surface cleaning head 190 in order to ensure a rotational movement of the spray arms. The liquid jets emitted by the cleaning nozzles 44, 46 can thus be directed perpendicularly to the surface 48 to be cleaned.

In 11 a seventh advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 200. The surface cleaning head 200 differs from the surface cleaning heads explained above by cleaning nozzles 202, 204, which are designed in a known manner, for example in the form of flat jet nozzles or point jet nozzles, and by spray arms 206, 208, which each have an oscillation device 212 at their free ends facing away from the axis of rotation 32, which is designed as a pulsation device 214 in the form of a resonator chamber 216. The resonator chambers 216 are each arranged immediately upstream of a cleaning nozzle 202, 204. The resonator chambers 216 each form a cylindrical cavity with an inlet opening 218 and an outlet opening 220. When the surface cleaning head 200 is in operation, the pressurized cleaning fluid flows through the resonator chamber 216. The inlet opening 218 is followed by a radially outward-facing step 222, at which the flow of the cleaning fluid separates, so that vortices are formed that move in the direction of flow within the resonator chamber 216, with a resonance oscillation forming in the resonator chamber 216 in the form of axially aligned pressure fluctuations of the cleaning fluid. The cleaning fluid emerging from the resonator chamber 216 thus exhibits temporal oscillations in the form of pressure fluctuations. This results in the liquid jets emitted by the cleaning nozzles 202, 204 dissolving at least partially into individual drops which impinge on the surface 11 to be cleaned with high impact force in order to clean it effectively, as already explained above.

As an alternative to arranging the resonator chambers 216 upstream of the cleaning nozzles 202, 204, the resonator chambers 216 can also be integrated into the cleaning nozzles 202, 204.

In 12 an eighth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 240. The surface cleaning head 240 has spray arms 242, 244, which, in contrast to the spray arms 206, 208 of the surface cleaning head 200 explained above, do not have any oscillation devices. Instead, an oscillation device 246 is used in the surface cleaning head 240 in the form of a pulsation device 248, which is arranged upstream of the spray arms 242, 244 in the inlet channel 26 of the surface cleaning head 240. The pulsation device 248 has a piezoceramic part 250 which is arranged in a radial extension 252 of the inlet channel 26 in the form of an annular body and has a central passage channel 254 through which the cleaning liquid supplied to the surface cleaning head 240 can flow.

The piezoceramic part 250 is connected to an alternating voltage generator 258 via an electrical connecting line 256 and can be supplied with an alternating electrical voltage by the generator. The application of the alternating voltage results in the piezoceramic part 250 carrying out mechanical oscillations radially aligned with respect to the axis of rotation 32, so that the pressurized cleaning liquid provided to the surface cleaning head 240 is subjected to pressure pulses. The pressure pulses spread in the flow direction of the cleaning liquid and result in the liquid jets emitted by the cleaning nozzles 202, 204 disintegrating by forming individual drops, as already explained above.

To supply energy to the AC generator 258, the surface cleaning head 240 has a rechargeable battery 260. The rechargeable battery 260 can be connected to an external charger via a charging socket 262.

In 13 a ninth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by reference numeral 270. The surface cleaning head 270 differs from the one described above with reference to 12 The surface cleaning head 120 explained above is characterized in that it has an oscillation device 272 in the form of a pulsation device 273 with a first piezoceramic part 274 and a second piezoceramic part 276. The first piezoceramic part 274 has a passage channel in which the second piezoceramic part 276 is arranged to form an annular gap 278. Pressurized cleaning fluid can flow through the annular gap 278 and is supplied to the cleaning nozzles 202, 204. Both piezoceramic parts 274, 276 can be supplied with an alternating electrical voltage from the alternating voltage generator 258, under the effect of which the two piezoceramic parts 274, 276 carry out mechanical oscillations so that the cleaning fluid flowing through the annular gap 278 is subjected to pressure pulses. As already explained above, the pressure pulses cause a disintegration of the liquid jets emitted by the cleaning nozzles 202, 204 by forming drops that impact the surface 11 to be cleaned with high impact force, so that the cleaning performance is significantly increased.

In 14 a tenth advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is designated overall by the reference numeral 280. The surface cleaning head 280 has an oscillation device 282 in the form of a pulsation device 284, which has a cuboid-shaped or cylindrical piezoceramic part 286, which can be supplied with alternating electrical voltage by the alternating voltage generator 258 and is thereby excited to mechanical oscillations. The piezoceramic part 286 has a pressure application surface 290 on an end face 288, via which the cleaning liquid that can be fed to the cleaning nozzles 202, 204 can be subjected to pressure pulses. For this purpose, the cleaning liquid is guided along the pressure application surface 290, the piezoceramic part 286 being arranged in a one-sided radial extension 292 of the inlet channel 26.

In 15 an eleventh advantageous embodiment of a surface cleaning head according to the invention is shown schematically, which is covered in its entirety with the reference caliper 300. The surface cleaning head 300 has an oscillation device 302 in the form of a pulsation device 304, which has a resonator chamber 306. The resonator chamber 306 forms a radial extension of the inlet channel 26, wherein the cleaning liquid that can be fed to the cleaning nozzles 202, 204 can flow through the resonator chamber 306. As already shown above using the example of the in 11 As explained in the schematically illustrated surface cleaning head 200, a resonance oscillation of the cleaning liquid forms in the resonator chamber 306, which applies pressure pulses to the cleaning liquid. Such resonator chambers are also referred to as Helmholtz resonators. Applying pressure pulses to the cleaning liquid results in the liquid jets emitted by the cleaning nozzles 202, 204 being at a short distance from the cleaning nozzles 202, 204 disintegrate, forming drops which impinge on the surface 11 to be cleaned with high impact force and thereby significantly increase the cleaning performance, as already explained above.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102007029245 A1 [0002]

Claims (29)

Surface cleaning head for cleaning a surface (11), with a hood-shaped housing (12) which is open downwards in a horizontal position of use of the surface cleaning head (10; 80; 120; 140; 160; 190; 200; 240; 270; 280; 300), in which at least one spray arm (40, 42; 82, 84; 122, 124; 142, 144; 162, 164; 192, 194; 206, 208; 242, 244) with a cleaning nozzle (44, 46; 202, 204) is mounted so as to be rotatable about an axis of rotation (32; 126), wherein the cleaning nozzle (44, 46; 202, 204) can be supplied with pressurized cleaning fluid and the cleaning nozzle (44, 46; 202, 204) together with the spray arm (40, 42; 82, 84; 122, 124; 142, 144; 162, 164; 192, 194; 206, 208; 242, 244) rotates about the axis of rotation (32; 126) to apply a liquid jet to the surface to be cleaned (11), characterized in that the surface cleaning head (10; 80; 120; 140; 160; 190; 200; 240; 270; 280; 300) has an oscillation device (50; 212; 246; 272; 282; 302) for generating temporal and/or spatial oscillations of the liquid jet generated by the liquid jet emitted from the cleaning nozzle (44, 46; 202, 204). Surface cleaning head after Claim 1 , characterized in that the oscillation frequency during a spatial oscillation of the liquid jet is at least 10 Hz. Surface cleaning head after Claim 1 , characterized in that the oscillation frequency during a temporal oscillation of the liquid jet is 10 kHz to 30 kHz. Surface cleaning head after Claim 1 , 2 or 3 , characterized in that the rotational speed of the at least one spray arm (40, 42; 82, 84; 122, 124; 142, 144; 162, 164; 192, 194; 206, 208; 242, 244) is a maximum of 15,000 revolutions per minute. Surface cleaning head after Claim 1 , characterized in that the oscillation frequency of the liquid jet is at least as high as the rotational speed of the at least one spray arm (40, 42; 82, 84; 122, 124; 142, 144; 162, 164; 192, 194; 206, 208; 242, 244). Surface cleaning head after Claim 5 , characterized in that the oscillation frequency of the liquid jet is a multiple of the rotational speed of the at least one spray arm (40, 42; 82, 84; 122, 124; 142, 144; 162, 164; 192, 194; 206, 208; 242, 244). Surface cleaning head according to one of the preceding claims, characterized in that the oscillation device (50) is integrated into the cleaning nozzle (44, 46). Surface cleaning head after Claim 7 , characterized in that the cleaning nozzle (44, 46) has a through-channel (54) and the oscillation device (50) forms a flow chamber (60) in the through-channel (54), in which a flow guide element (62) is arranged for generating a spatial oscillation of the liquid jet emitted by the cleaning nozzle (44, 46). Surface cleaning head after Claim 8 , characterized in that the flow guide element (62) divides the flow chamber (60) into a central flow channel (64) and two opposing feedback channels (66, 68), wherein the feedback channels (66, 68) connect an output section (70) of the central flow channel (64) to an input section (72) of the central flow channel (64). Surface cleaning head according to one of the Claims 1 until 7 , characterized in that the oscillation device (212; 246; 272; 282; 302) is designed as a pulsation device (214; 248; 273; 284; 304) for generating temporal oscillations in the form of pressure fluctuations of the liquid jet emitted by the at least one cleaning nozzle (202, 204). Surface cleaning head after Claim 10 , characterized in that the cleaning liquid can be subjected to pressure pulses by means of the pulsation device (214; 248; 273; 284; 304). Surface cleaning head after Claim 11 , characterized in that the pulsation device (214; 306) has a resonator chamber (216; 306) which forms a pressure resonator for subjecting the cleaning liquid to pressure pulses. Surface cleaning head after Claim 12 , characterized in that the resonator chamber is integrated into the cleaning nozzle. Surface cleaning head after Claim 12 , characterized in that the resonator chamber (216; 306) can be flowed through by the cleaning liquid that can be supplied to the cleaning nozzle (202, 204). Surface cleaning head after Claim 12 , characterized in that the resonator chamber (216) is arranged in the at least one spray arm (206, 208). Surface cleaning head after Claim 15 , characterized in that the resonator chamber (216) is arranged immediately upstream of the cleaning nozzle (202, 204). Surface cleaning head after Claim 12 , characterized in that the resonator chamber (306) is arranged upstream of the at least one spray arm (242, 244). Surface cleaning head after Claim 10 or 11 , characterized in that the pulsation device (248; 273; 284) has at least one piezoceramic part (250; 274, 276; 286) which can be subjected to an alternating electrical voltage, wherein the cleaning liquid can be subjected to pressure pulses by the at least one piezoceramic part (250; 274, 276; 286). Surface cleaning head after Claim 18 , characterized in that at least one piezoceramic part (250) has a passage channel (254) through which the cleaning liquid can flow. Surface cleaning head after Claim 18 , characterized in that the pulsation device (273) has a first and a second piezoceramic part (274, 276), wherein the first piezoceramic part (274) has a passage channel in which the second piezoceramic part (276) is arranged to form an annular gap (278) through which the cleaning liquid can flow. Surface cleaning head after Claim 18 , characterized in that at least one piezoceramic part (286) is cuboid-shaped or cylindrical and has a pressure application surface (290) on one end face (288) for applying pressure pulses to the cleaning liquid. Surface cleaning head according to one of the Claims 18 until 21 , characterized in that the surface cleaning head (240; 270; 280) has a battery-operated alternating voltage generator (258) for applying an electrical alternating voltage to the at least one piezoceramic part (250; 274, 276; 286). Surface cleaning head according to one of the Claims 10 until 12 or 18 until 22 , characterized in that the surface cleaning head (240; 270; 280; 300) has an inlet channel (26) for the pressurized cleaning liquid upstream of the at least one spray arm (242, 244), wherein the cleaning liquid in the region of the inlet channel (26) can be subjected to pressure pulses by means of the pulsation device (248; 273; 284; 304). Surface cleaning head according to one of the preceding claims, characterized in that the orientation of the at least one cleaning nozzle (44, 46) in the direction of the surface to be cleaned (11) is adjustable. Surface cleaning head after Claim 24 , characterized in that the at least one spray arm (82, 84) has an inner and an outer spray arm section (86, 88; 90, 92) relative to the axis of rotation (32), wherein a cleaning nozzle (44, 46) is held on the outer spray arm section (90, 92) and the outer spray arm section (90, 92) is detachably connectable to the inner spray arm section (86, 88) in different rotational positions relative to the longitudinal axis (102, 104) of the spray arm (82, 84). Surface cleaning head according to one of the preceding claims, characterized in that an additional nozzle (146, 148) for dispensing cleaning fluid is arranged on the at least one spray arm (142, 144), which is oriented tangentially with respect to the direction of rotation of the at least one spray arm (142, 144). Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (190) has a turbine wheel (196) which is connected in a rotationally fixed manner to the at least one spray arm (192, 194) and which can be acted upon by the cleaning liquid which can be supplied to the cleaning nozzle (44, 46). Surface cleaning head according to one of the Claims 1 until 26 , characterized in that the surface cleaning head (160) has a motorized rotary drive (166), wherein the at least one spray arm (162, 164) can be rotated about the axis of rotation (32) by means of the rotary drive (166). Surface cleaning head according to one of the preceding claims, characterized in that the axis of rotation (126) of the at least one spray arm (122, 124) is inclined to the vertical in a horizontal position of use of the surface cleaning head (120).

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