Device for enveloping a liquid jet with an air flow and liquid dispensing device comprising such a device

Abstract

The invention relates to a device (14; 92) for enclosing a liquid jet (42) that expands in a fan shape in a jet plane (44) with an airflow, wherein the device (14; 92) forms a housing (30; 104) that surrounds a through channel (36) and has at least one air intake opening (46, 48), wherein the through channel (36) has a first channel section (38) for receiving the liquid jet (42) and a second channel section (40) for discharging the liquid jet (42), wherein the first channel section (38) is in flow communication with the at least one air intake opening (46, 48) and the second channel section (40) expands in the jet plane (44).To further develop the device (14; 92) so that it can be attached to a dispensing element in a more user-friendly manner, the invention proposes that the housing (30; 104) has a retaining section (32; 106) which is configured for the detachable and rotationally fixed attachment of the device (14; 92) to a dispensing element (12; 94) which has a flat jet nozzle (22; 102). A liquid dispensing device (10; 90) with such a device (14; 92) is also proposed.

Description

[0001] The invention relates to a device for enveloping a liquid jet expanding fan-shaped in a jet plane with an air flow, wherein the device forms a housing which surrounds a through-channel and has at least one air intake opening, wherein the through-channel has a first channel section for receiving the liquid jet and a second channel section for discharging the liquid jet, and wherein the first channel section is in flow connection with the at least one air intake opening and the second channel section expands in the jet plane.

[0002] Furthermore, the invention relates to a liquid dispensing device for dispensing a liquid jet expanding fan-shaped in a jet plane, comprising a device of the above type and comprising a dispensing member which is detachably connectable to a liquid supply line and has a flat jet nozzle, wherein the device is detachably connectable to the dispensing member.

[0003] Dispensing devices with a flat jet nozzle for dispensing a fan-shaped liquid jet are used, for example, as accessories for pressure cleaning devices to cover an object to be cleaned with a fan-shaped liquid jet. The dispensing devices can be designed, for example, as a jet pipe with an integrated flat jet nozzle. Pressurized water can be used as the liquid, for example. Such flat jet nozzles are known, for example, from WO 2014 / 090333 A1.

[0004] The fan-shaped liquid jet emerging from the flat jet nozzle interacts with the ambient air on its way to the object to be cleaned. This slows down the liquid jet and causes it to lose its compactness. To counteract this effect, JP 2004-223409 A proposes a liquid dispensing device which, in addition to a dispensing element in the form of a supply pipe carrying a flat jet nozzle at its free end, uses a device for enveloping the fan-shaped liquid jet emanating from the flat jet nozzle. The supply pipe is welded to a retaining plate, which in turn is screwed to the device. The device consists of two housing halves welded together, which are screwed to the retaining plate and surround a through-channel that extends through the housing.The through-channel has a first channel section for receiving the liquid jet emanating from the flat jet nozzle and a second channel section for dispensing the liquid jet. The first channel section is in flow communication with two air intake openings of the housing, and the second channel section continuously widens with increasing distance from the first channel section. This allows air to be mixed into the liquid jet, with the air forming an air jacket that surrounds the liquid jet and can be discharged together with the liquid jet from the liquid dispensing device. The air jacket reduces the interaction of the liquid jet with the ambient air, in particular reducing the deceleration of the liquid jet and lessening its compactness.The first channel section of the through-channel receives the liquid jet emanating from the flat jet nozzle, which exits at considerable speed. Air is drawn in through the air intake openings and then surrounds the liquid jet in a sheath-like manner. Using the device, the liquid jet emanating from the flat jet nozzle of the dispensing device can be enveloped in a sheath-like air flow to reduce the deceleration of the liquid jet due to its interaction with the ambient air. However, handling the device when attached to the dispensing device is not particularly user-friendly.

[0005] The object of the present invention is therefore to further develop a device of the generic type in such a way that it can be attached to a dispensing device in a more user-friendly manner.

[0006] This object is achieved according to the invention in a device of the type mentioned at the outset in that the housing has a holding section which is designed for the detachable and rotationally fixed fastening of the device to a dispensing element which has a flat jet nozzle.

[0007] By means of the holding section, the device according to the invention can be easily attached to a dispensing element having a flat jet nozzle. If necessary, the device can also be easily detached from the dispensing element again. The dispensing element, for example a jet pipe with an integrated flat jet nozzle, can be connected in the usual way to a pressure cleaning device via a liquid supply line, so that pressurized liquid can be supplied to the dispensing element, which can be fed to the device according to the invention via the flat jet nozzle in the form of a fan-shaped liquid jet, wherein the liquid jet can be received by the first channel section of the through-channel and subsequently discharged via the second channel section of the through-channel.The holding section enables a simple, detachable and rotationally fixed attachment of the device to the dispensing element, whereby the rotationally fixed attachment ensures that the device maintains its rotational position relative to the dispensing element, so that the liquid jet emanating from the flat jet nozzle can flow unhindered through the passage channel of the housing, in particular the fan-shaped, widening second channel section.

[0008] By means of the holding section, the device according to the invention can be attached to the dispensing device without the need for an additional connecting part, such as a holding plate that must be welded to the dispensing device and screwed to the device. Handling the device according to the invention when attaching it to the dispensing device is thus very simple and user-friendly.

[0009] It is advantageous if the holding section is designed for tool-free, detachable and non-rotatable attachment of the device to a dispensing device. This makes handling the device particularly user-friendly when attaching it to the dispensing device.

[0010] The holding section can, for example, form an elastically expandable retaining clip that can be clipped onto an end section of the dispensing element. Clipping can occur axially relative to a longitudinal axis of the dispensing element, or at an angle or perpendicular to the longitudinal axis. The retaining clip can, for example, be C- or U-shaped.

[0011] It is advantageous if the holding section has a non-circular, in particular wavy-shaped, retaining ring. The retaining ring can be placed on an end section of the dispensing member, for example, in the axial direction relative to a longitudinal axis of the dispensing member. In particular, with such a configuration, the device according to the invention can form an attachment part that can be placed on the dispensing member and also removed again. The non-circular shape of the cross-section of the retaining ring enables a rotationally fixed connection of the retaining ring to the dispensing member in a structurally simple manner. A wavy-shaped cross-section of the retaining ring has proven particularly advantageous.

[0012] The holding section preferably has at least one locking element. This allows the holding section to be locked to the dispensing member, wherein the locking element of the holding section can interact with a complementarily designed locking element of the dispensing member to form a locking connection.

[0013] It is particularly advantageous if the holding section has at least one coding element for positioning the device in a predetermined rotational position relative to the dispensing element. By means of the at least one coding element, the device can be attached to a dispensing element in a rotational position in which the second channel section of the device is aligned in the jet plane of the liquid jet emanating from the flat jet nozzle of the dispensing element. The at least one coding element forms a positioning aid that facilitates the user's attachment of the device to a dispensing element in a predetermined rotational position.

[0014] At least one coding element can be designed, for example, in the form of a coding slot which, when the device is attached to the dispensing member, receives a complementarily designed coding rib of the dispensing member.

[0015] Alternatively or additionally, it can be provided that at least one coding element forms a contact surface which can be applied flatly to a complementarily designed contact area of ​​the dispensing member.

[0016] As mentioned at the outset, the housing of the device according to the invention has a through-channel through which the liquid jet can flow, comprising a first channel section for receiving the liquid jet and a second channel section for discharging the liquid jet, wherein the first channel section is in flow connection with at least one air intake opening and the second channel section widens with increasing distance from the first channel section in the jet plane. In a particularly preferred embodiment of the invention, the second channel section has a longitudinal region extending over at least part of its total length, in which the second channel section narrows perpendicular to the jet plane with increasing distance from the first channel section.

[0017] In such a configuration of the device according to the invention, the second channel section of the housing widens with increasing distance from the first channel section in the jet plane and has a longitudinal region extending at least over part of its total length, in which it narrows perpendicular to the jet plane with increasing distance from the first channel section. The longitudinal region extending at least over part of the total length of the second channel section, in which the second channel section narrows perpendicular to the jet plane, counteracts an increase in the cross-sectional area of ​​the second channel section caused by the widening of the second channel section in the jet plane. This, in turn, counteracts a reduction in the flow velocity of the air jacket surrounding the liquid jet within the second channel section.The flow velocity of the air jacket depends on the size of the cross-sectional area of ​​the second channel section. The more the cross-sectional area increases with increasing distance from the first channel section, the more the flow velocity of the air jacket decreases. By narrowing the second channel section perpendicular to the jet plane in the longitudinal region extending over at least part of the total length of the second channel section, an increase in the cross-sectional area caused by the widening of the second channel section in the jet plane can be at least partially compensated. This, in turn, has the effect that the flow velocity of the air jacket surrounding the liquid jet in the circumferential direction within the second channel section is less affected.The reduced impact on the flow velocity of the air jacket, in turn, results in the liquid jet being slowed down less within the second channel section and the compactness of the liquid jet being less compromised. With such a design, the device according to the invention is not only characterized by user-friendly handling when attached to a dispensing device, but it is also characterized by the fact that improved cleaning performance can be achieved when the device is used to clean an object. Furthermore, with such a design of the device, the liquid jet can be fanned out further, so that a larger cleaning width can be achieved with the same cleaning performance.

[0018] The longitudinal region of the second channel section, in which it narrows with increasing distance from the first channel section perpendicular to the jet plane of the liquid jet, preferably extends over at least 50% of the total length of the second channel section, in particular over at least 75%, for example at least 80%.

[0019] In particular, it can be provided that the longitudinal region of the second channel section, in which it narrows perpendicular to the jet plane with increasing distance from the first channel section, extends over the entire length of the second channel section. In such a configuration of the device according to the invention, the aforementioned longitudinal region extends to the free end of the second channel section.

[0020] Alternatively, it can be provided that the above-mentioned longitudinal region of the second channel section is adjoined by an end region of the second channel section which widens perpendicular to the beam plane with increasing distance from the first channel section or remains constant with respect to its extension perpendicular to the beam plane.

[0021] The device according to the invention for enveloping a fan-shaped expanding liquid jet with an air flow is suitable in combination with a discharge element with an integrated flat jet nozzle in particular for use in pressure cleaning devices which provide a cleaning liquid, in particular water, at a pressure of 10 bar to 3,000 bar, in particular 10 bar to 300 bar.

[0022] In order to be able to produce the housing cost-effectively, it is advantageous if the housing is designed as a one-piece plastic molded part.

[0023] The housing preferably consists of a semi-crystalline plastic material, in particular of a polypropylene, polyethylene, polyoxymethylene or polyamide material.

[0024] It is advantageous if the housing, designed as a one-piece plastic molded part, has a housing base that forms the first channel section of the through-channel and to which two housing sections are connected, which form the second channel section, wherein at least one of the housing sections has a rigid deformation zone of the housing base directly in front of it. Such a design makes it possible to produce the housing cost-effectively using an injection molding process, wherein the housing initially has a demolding configuration in which the two housing sections are spread apart. After demolding, the housing can be converted into a use configuration by bending the at least one deformation zone, in which the two housing sections abut one another and define the second channel section between them.

[0025] As already mentioned, the second channel section widens in the jet plane with increasing distance from the first channel section, and preferably the second channel section narrows perpendicular to the jet plane, at least over part of its total length, with increasing distance from the first channel section. In order to be able to achieve such a geometry in a simple manner using the injection molding process, the housing can be manufactured in the injection molding process in a demolding configuration in which the two housing sections are spread apart so that the housing can be easily demolded. After demolding, the at least one flexible deformation zone can be bent so far that the two housing sections abut one another and define the second channel section of the through-channel between them. Difficulties during demolding of the housing can thus be easily avoided.In the position of use of the housing, the geometry of the second channel section ensures that the flow velocity of the air jacket surrounding the liquid jet is only slightly affected and consequently the liquid jet is at most slightly slowed down and loses its compactness.

[0026] In a preferred embodiment of the device according to the invention, the housing base has two opposing air intake openings in the region of the first channel section of the through-channel, which are located directly upstream of the second channel section and are connected to one another via the at least one deformation zone. With such a configuration, the flow resistance of the air sucked into the first channel section under the action of the liquid jet can be kept particularly low, since the air intake openings open directly into the first channel section, and when the housing transitions from the demolding configuration to the use configuration, the at least one deformation zone, which is arranged between the opposing air intake openings of the first channel section, is deformed.

[0027] In particular, it can be provided that the two air intake openings are connected to each other via two deformation zones of the housing base which are opposite one another and arranged outside the jet plane.

[0028] It is advantageous if the two deformation zones are arranged mirror-symmetrically to the beam plane.

[0029] The opening axes of the air intake openings are advantageously aligned coaxially to each other and arranged in the jet plane of the liquid jet.

[0030] It is advantageous if the material thickness of the housing is thinner in the area of ​​the at least one deformation zone than outside the at least one deformation zone. The thinner material thickness in the area of ​​the at least one deformation zone facilitates the bending of the at least one deformation zone during the transition from the demolding configuration to the use configuration.

[0031] In a particularly preferred embodiment of the device, the two housing sections, which define the second channel section of the through-channel between them, can be secured to one another. The mutual securing of the two housing sections imparts high flexural rigidity to the housing sections in the housing's use configuration, so that the housing sections can withstand even high external bending loads in the use configuration without the risk of them shifting relative to one another under mechanical stress.

[0032] It is advantageous if the two housing sections can be locked together. For this purpose, the two housing sections can have interacting locking elements, such as locking hooks, which engage behind each other in a locked position.

[0033] It is advantageous if the two housing sections form edge regions that limit the extent of the second channel section in the beam plane and have projections and recesses that interlock in pairs perpendicular to the beam plane. The edge regions of the two housing sections form channel walls of the second channel section of the through-channel, which limit the extent of the second channel section in the beam plane. The edge regions have projections and recesses that interlock in pairs when the housing is in use. The edge sections thus form a type of interlocking, which imparts very high flexural rigidity to the two housing sections in the use configuration of the housing.

[0034] As already mentioned, the invention also relates to a liquid dispensing device for dispensing a liquid jet expanding fan-shaped in a jet plane, wherein the liquid dispensing device has a device of the type explained above and a dispensing member which is detachably connectable to a liquid supply line and has a flat jet nozzle, wherein the device is detachably and non-rotatably connectable to the dispensing member.

[0035] As already mentioned, the device according to the invention can form an attachment part for the dispensing member.

[0036] The dispensing device can be designed as a jet pipe with a single nozzle in the form of a flat jet nozzle. Such jet pipes are also referred to as single jet pipes.

[0037] Alternatively, the dispensing device can be designed as a multiple jet pipe with several nozzles through which a liquid jet can be selectively discharged, with one of the nozzles being designed as a flat jet nozzle. Such multiple jet pipes are known, for example, from WO 2012 / 095238 A1.

[0038] The following description of advantageous embodiments of the invention serves to explain it in more detail in conjunction with the drawings. They show: Figure 1: a side view of a first embodiment of a liquid dispensing device with a dispensing element in the form of a multiple jet pipe and with a first embodiment of a device for enveloping a liquid jet with an air flow; Figure 2: a side view of the device from Figure 1 ; Figure 3: a plan view of the device from Figure 1 ; Figure 4: a front view of the device from Figure 1; Figure 5: a sectional view of the device along the line 5-5 in Figure 2 ; Figure 6: a sectional view of the device along the line 6-6 in Figure 2 ; Figure 7: a sectional view of the device along the line 7-7 in Figure 3 ; Figure 8: a front view of the device according to Figure 4 , wherein a housing of the device assumes a demolding configuration; Figure 9: a sectional view of the device along the line 9-9 in Figure 8 ; Figure 10: a sectional view of the liquid dispensing device along the line 10-10 in Figure 1 ; Figure 11: a perspective view of an end region of the dispensing device from Figure 1; Figure 12: a perspective view of a second embodiment of a liquid dispensing device with a dispensing element in the form of a single jet pipe and with a second embodiment of a device for enveloping a liquid jet with an air flow; Figure 13: a plan view of the liquid dispensing device from Figure 12 ; Figure 14: a front view of the liquid dispensing device from Figure 12 ; Figure 15: a sectional view of the liquid dispensing device along the line 15-15 in Figure 14 ; Figure 16: a sectional view of the liquid dispensing device along the line 16-16 in Figure 13 ; Figure 17: an enlarged view of detail X from Figure 16 .

[0039] In the Figures 1 to 11 A first advantageous embodiment of a liquid dispensing device according to the invention is shown schematically and is designated overall by the reference numeral 10.

[0040] The liquid dispensing device 10 has a dispensing element in the form of a multiple jet pipe 12 and a first advantageous embodiment of a device 14 according to the invention for enveloping a liquid jet provided by the multiple jet pipe 12 and expanding in a fan-shaped manner in a jet plane with a jacket-shaped air flow.

[0041] The multiple jet pipe 12 has a bayonet connection element 18 at a first end region 16, with the aid of which the multiple jet pipe 12 can be connected to a liquid supply line which is known per se and therefore not shown in the drawing for the sake of clarity, via which liquid can be supplied to the multiple jet pipe from a pressure cleaning device which is known per se and therefore also not shown in the drawing. As can be seen in particular from Figure 10As is clear, the multiple jet pipe 12 has three differently designed nozzles at a second end region 20 facing away from the first end region 16: a flat jet nozzle 22, a rotor nozzle 24 and a point jet nozzle 26, through which the supplied liquid can be selectively discharged. For this purpose, the jet pipe 12 has a nozzle switching arrangement which is known per se and therefore not shown in the drawing for the sake of clarity, which is coupled to an outer sleeve 28 which can be grasped by the user. The outer sleeve 28 is rotatable about a longitudinal axis of the jet pipe, and depending on the rotational position of the outer sleeve 28, the nozzle switching arrangement opens up a flow path from the first end region 16 to one of the nozzles 24, 26 or 28, so that depending on the rotational position of the outer sleeve 28, a liquid jet can be selectively discharged via one of the nozzles 24, 26, 28.Such multiple jet pipes are known to the person skilled in the art, for example from WO 2012 / 095238 A1.

[0042] The flat jet nozzle 22 can be used to deliver a liquid jet that expands fan-shaped in the jet direction. Such flat jet nozzles are known to those skilled in the art, for example, from WO 2014 / 090333 A1. The point jet nozzle 26 can be used to deliver a point jet, i.e., a liquid jet that expands only slightly in the jet direction. The rotor nozzle 24 can be used to generate a point jet circulating on a conical surface. Such point jet and rotor nozzles are also known to those skilled in the art.

[0043] The device 14 is designed in the manner of an attachment which is placed on the second end region 20 of the jet pipe.

[0044] As can be seen from the Figures 2 to 10As can be seen, the device 14 has a housing 30 which comprises a housing base 31. A holding section 32 of the housing 30, which is designed in the form of a holding ring 33, is arranged in front of the housing base 31 in the direction of the multiple jet pipe 12. The holding ring 33 is essentially Wankel-shaped in cross section. This is particularly evident from Figure 10 The cross-sectional shape of the retaining ring 33 largely corresponds to the cross-sectional shape of the second end region 20 of the multiple jet pipe 12. The non-circular cross-sectional shape ensures that the device 14 is held in a rotationally fixed manner on the multiple jet pipe 12.

[0045] On its inner side facing the multiple jet pipe 12, the retaining ring 33 has three locking projections 34 evenly distributed in the circumferential direction, each of which engages a locking recess 35 arranged on the outer side of the multiple jet pipe 12. The device 14 can thus be locked to the multiple jet pipe 12 and can be detached from the multiple jet pipe 12 as needed.

[0046] In the area between two locking recesses 35, the multiple jet pipe 12 has on its outer side a contact area in the form of a shoulder 36, to which a contact surface 37 arranged on the inside of the retaining ring 33 is assigned, which contact surface 37 comes to rest on the shoulder 36 when the retaining ring 33 is placed on the end area 20 of the multiple jet pipe 12. This is particularly evident from the Figures 10 and 11The shoulder 36 and the contact surface 37 form mutually associated coding elements that ensure that the device 14 can only be placed on the end region 20 of the multiple jet pipe 12 in a predetermined rotational position relative to the multiple jet pipe 12.

[0047] Adjacent to the flat jet nozzle 22 is a through-channel 36 of the device 14, which is surrounded by the housing 30. The through-channel 36 has a first channel section 38 and a second channel section 40 immediately adjacent thereto. The first channel section 38 receives the liquid jet emanating from the flat jet nozzle 22. The flat jet nozzle 22 is in the Figures 6 and 7 shown in dashed lines for easier orientation, and the liquid jet emanating from the flat jet nozzle 22 is shown in the Figures 6 and 7For easier orientation, it is shown in dash-dotted lines and is assigned the reference number 42. The liquid jet 42 expands fan-shaped in the jet direction and defines a jet plane 44. This is particularly evident from the Figures 6 and 7 clearly.

[0048] The liquid jet is discharged via the second channel section 40 so that it can be directed, for example, onto an object to be cleaned. To allow the liquid jet 42 to flow through the second channel section 40 without contact, the second channel section 40 continuously widens in the jet plane 44 with increasing distance from the first channel section 38.

[0049] Perpendicular to the jet plane 44, the second channel section 40 narrows continuously over its entire length with increasing distance from the first channel section 38. This is particularly evident from Figure 7The continuous widening in the beam plane 44 and the continuous narrowing perpendicular to the beam plane 44 ensure that, although the shape of the cross-sectional area of ​​the second channel section 40 continuously changes with increasing distance from the first channel section 38, the size of the cross-sectional area of ​​the second channel section 40 remains practically constant over its entire length.

[0050] The housing base 31 surrounds the first channel section 38, which has two opposite, identically designed air intake openings 46, 48. The air intake openings 46, 48 are located directly in front of the second channel section 40. As can be seen in particular from Figure 6 As is clear, the opening axes 50, 52 of the air intake openings 46, 48, i.e. the central axes of the air intake openings 46, 48, are aligned coaxially with one another and arranged in the jet plane 44 of the liquid jet 42.

[0051] Within the first channel section 38, a negative pressure is created by the action of the liquid jet 42 emerging from the flat jet nozzle 22, so that air is sucked into the first channel section 38 via the air intake openings 46, 48 and mixed with the liquid jet 42. This creates an air jacket that surrounds the liquid jet 42 in the circumferential direction. The flow velocity of the air jacket remains practically constant within the second channel section 40 because the size of the cross-sectional area of ​​the second channel section 40 remains practically constant over its entire length. As already mentioned, although the second channel section 40 widens in the jet plane 44, the associated increase in the cross-sectional area is compensated for by the narrowing of the second channel section 40 perpendicular to the jet plane.The virtually constant flow velocity of the air jacket means that flow losses of the liquid jet 42 within the second channel section 40 can be kept to a minimum. In particular, the deceleration of the liquid jet 42 within the second channel section 40 can be kept to a minimum, and the compactness of the liquid jet 42 is only slightly impaired. This improves the cleaning effect that can be achieved by means of the liquid jet 42.

[0052] On the side of the housing base 31 facing away from the holding section 32, a first housing section 54 and a second housing section 56 are connected, which define the second channel section 40 of the through-channel 36 between them. Directly upstream of the first housing section 54, the housing base 31 forms a first web-like, flexible deformation zone 58 between the two air intake openings 46, 48, and directly upstream of the second housing section 56, the housing base 31 forms a second web-like, flexible deformation zone 60 between the two air intake openings 46, 48. The two deformation zones 58, 60 are identically designed and arranged mirror-symmetrically to the beam plane. This is particularly evident from Figure 2The housing 30 has a thinner material thickness in the area of ​​the two deformation zones 58, 60 than outside the deformation zones 58, 60. This allows the alignment of the two housing sections 54, 56 to be changed during the manufacture of the housing 30.

[0053] The housing 30 is designed as a one-piece plastic molded part and consists of a semi-crystalline material, for example a polypropylene, polyethylene, polyoxymethylene or polyamide material.

[0054] An injection molding process is used to manufacture the housing 30, wherein the housing 30 initially assumes a demolding configuration in which the two housing sections 54, 56 are spread apart. The demolding configuration of the housing 30 is shown in the Figures 8 and 9shown schematically. This configuration allows the housing 30 to be demolded easily despite the geometry of the second channel section 40 which continuously widens in the beam plane and continuously narrows perpendicular to the beam plane 44. After demolding, the housing 30 is deformed in the region of the deformation zones 58, 60 into the Figures 1 to 7 The housing is deformed into the illustrated use configuration, in which the two housing sections 54, 56 abut one another. During the transition from the demolding configuration to the use configuration, the flexible deformation zones 58, 60 bend like film hinges.

[0055] In the use configuration of the housing 30, the two housing sections 54, 56 can be secured to one another. This provides the housing sections 54, 56 with high flexural rigidity in the use position.

[0056] As is particularly evident from Figure 5As is clear, the two housing sections 54, 56 each have two edge regions 62, 64 and 66, 68, respectively, which limit the extent of the second channel section 40 in the jet plane. The edge regions 62, 64, 66, and 68 have pairwise interacting locking hooks 70, 72, which engage behind one another in the use position of the housing 20 and form a locking connection, so that the housing sections 54, 56 can be locked together in the use position of the housing 30. The locking hooks 70, 72 extend in the longitudinal direction of the second channel section 40 in a central section of the edge regions 62, 64, 66, 68 and in an end section of the edge regions 62, 64, 66, 68. In the intermediate sections, the edge regions 62, 64 of the first housing section 54 have recesses 74, 76, into which a complementarily designed projection 78, 80 of the edge regions 66, 68 of the second housing section 56 engages in a form-fitting manner. This is particularly evident from Figure 2 The recesses 74, 76 and the projections 78, 80 thus form an interlocking of the two housing sections 54, 56 in the region of the beam plane 44, which further increases the flexural rigidity of the housing 30. In particular, the recesses 74, 76 and the projections 78, 80 ensure that the two housing sections 54, 56 do not shift relative to one another when subjected to an external bending moment.

[0057] By means of the device 14, a liquid jet 42 emanating from the flat jet nozzle 22, which expands in a fan shape, can be enveloped by a jacket-shaped air flow, which can minimize the interference of the liquid jet 42 by the ambient air. The housing 30 of the device 14 can be manufactured cost-effectively using a plastic injection molding process, initially assuming a demolding configuration that allows the housing 30 to be easily demolded despite the geometry of the second channel section 40, which expands in the jet plane and tapers perpendicular to the jet plane.For this purpose, the two housing sections 54, 56, which define the second channel section 40, are spread apart in the demolding configuration, whereas in the use configuration of the housing 30 they abut one another with lateral edge regions, wherein the edge regions can be locked together and, by providing the recesses 74, 76 and the projections 78, 80, form a toothing which imparts a high flexural rigidity to the housing sections 54, 56 in the use position despite the provision of the two flexible deformation zones 58, 60, which deform when the housing transitions from the demolding position to the use position.

[0058] In the Figures 12 to 17A second advantageous embodiment of a liquid dispensing device according to the invention is schematically shown, which is designated overall by the reference numeral 90. The liquid dispensing device 90 has a dispensing element in the form of a single jet pipe 94 and a second advantageous embodiment of a device according to the invention for enveloping a liquid jet provided by the single jet pipe 94 and expanding fan-shaped in a jet plane with a jacket-shaped air flow, wherein the device is designated by the reference numeral 92.

[0059] In a manner corresponding to the multiple jet pipe 12 of the liquid dispensing device 10 explained above, the single jet pipe 94 also has a first end region 96 on which a bayonet connecting member 98 is arranged for detachable connection to a liquid supply line, via which liquid pressurized by a pressure cleaning device can be supplied to the liquid dispensing device 90.

[0060] At a second end region 100 facing away from the first end region 96, the single jet tube 94 has a flat jet nozzle 102. The flat jet nozzle 102 can be configured identically to the flat jet nozzle 22 mentioned above with reference to the first liquid dispensing device 10.

[0061] The device 92 forms an attachment that can be placed on the second end portion 100 of the single jet pipe 94. The device 92 is largely identical to the device 14 explained above. For identical components of the device 92, therefore, Figures 12 to 17 the same reference numerals are used as in the Figures 1 to 11 , and with regard to these components, reference is made to the preceding explanations to avoid repetition.

[0062] The device 92 differs from the device 12 in that it has a housing 104 that forms a holding section 106 in the form of a circular-cylindrical holding sleeve 108 that can be placed onto the cylindrically designed second end region 100 of the single-jet pipe 94 and removed again if necessary. The end region 100 has a plurality of outwardly directed ribs 110 on its outer side, arranged axially offset from one another. The holding sleeve 108 has radially inward-facing locking projections 112 on its inner side, which, when the device 92 is placed onto the end region 100 of the single-jet pipe 94, penetrate into a space 114 between two adjacent ribs 110. In this way, the device 92 can be locked to the single-jet pipe 94. If necessary, the device 92 can also be removed from the single-jet pipe by releasing the locking connection.

[0063] To ensure a rotationally fixed connection and to align the second channel section 40 of the device 92 in the jet plane of the liquid jet emanating from the flat jet nozzle 102, the holding sleeve 108 has a coding element in the form of a coding slot 116, which interacts with a complementarily designed coding element in the form of a coding rib 118 arranged on the outside of the single jet tube 94. When the device 92 is placed on the second end region 100 of the single jet tube 94, the coding slot 110 can accommodate the coding rib 112. The device 92 is thereby secured against rotation relative to the jet tube 94 and at the same time it is ensured that the second channel section 40 of the housing 104 is aligned coplanar with the jet plane of the liquid jet emanating from the flat jet nozzle 102.

[0064] The housing 104 is designed as a one-piece plastic molded part in a manner similar to the housing 30 explained above and can be manufactured by injection molding, wherein the housing 104 initially assumes a demolding configuration and can then be converted into a usage configuration, as already explained above.

Claims

1. A device for enveloping a liquid jet (42) expanding fan-shaped in a jet plane (44) with an air flow, wherein the device (14; 92) forms a housing (30; 104) which surrounds a through-channel (36) and has at least one air intake opening (46, 48), wherein the through-channel (36) has a first channel section (38) for receiving the liquid jet (42) and a second channel section (40) for discharging the liquid jet (42), and wherein the first channel section (38) is in flow connection with the at least one air intake opening (46, 48) and the second channel section (40) expands in the jet plane (44), characterized in that the housing (30; 104) has a holding section (32; 106) which is designed for the detachable and rotationally fixed fastening of the device (14; 92) to a dispensing member (12; 94) which has a flat jet nozzle (22; 102).

2. Device according to claim 1, characterized in thatthe holding section (32; 106) is designed for tool-free, detachable and rotationally fixed fastening of the device (14; 92) to a dispensing member (12; 92).

3. Device according to claim 1 or 2, characterized in that the holding section (32) has a holding ring (34) which is non-circular in cross section.

4. Device according to claim 1, 2 or 3, characterized in that the holding section (32; 106) has at least one locking element (34; 112).

5. Device according to one of the preceding claims, characterized in that the holding section (32; 106) has at least one coding element (37; 110) for positioning the device (14; 92) in a predetermined rotational position relative to the dispensing member.

6. Device according to claim 5, characterized in that at least one coding element is designed in the form of a coding slot (116).

7. Device according to claim 5 or 6, characterized in that at least one coding element forms a contact surface (37).

8. Device according to one of the preceding claims, characterized in that the second channel section (40) has a longitudinal region extending at least over part of its total length, in which the second channel section (40) narrows with increasing distance from the first channel section (38) perpendicular to the jet plane (44).

9. Device according to one of the preceding claims, characterized in that the housing (30; 104) is designed as a one-piece plastic molded part.

10. Device according to claim 9, characterized in that the housing (30) consists of a semi-crystalline plastic material.

11. Liquid dispensing device for dispensing a liquid jet (42) widening in a fan-shaped manner in a jet plane, comprising a device (14; 92) according to one of the preceding claims and comprising a dispensing member (12; 94) which is detachably connectable to a liquid supply line and has a flat jet nozzle (22; 102), wherein the device (14; 92) is detachably and non-rotatably connectable to the dispensing member (12; 94).

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