Liquid dispensing device

Abstract

The invention relates to a liquid dispensing device which has a jet generating part (44) with a flat jet nozzle (50), and a housing (12) which at least partially receives the jet generating part (44) and in which a channel structure (74) is arranged or formed which has a liquid receiving section (78) arranged downstream of the flat jet nozzle (50), a liquid dispensing section (80) adjoining the liquid receiving section (78), and at least one air intake section (76). The liquid receiving section (78) is fluidically connected to at least one air intake opening (72) via the at least one air intake section (76). The liquid dispensing section (80) extends as far as an outlet opening (26) of the housing (12) and widens in a fan-shaped manner. In order to minimize the risk of clogging or wear of the channel structure (74), a filter device (90; 152; 202; 232) with at least one through-opening (102; 154; 206; 238) is arranged on the at least one air intake opening (76), which has at least two mutually opposite edge sections (106, 108; 158, 160; 210, 212) arranged at a distance from one another which is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure (74).

Description

[0001] LIQUID DISPENSING DEVICE

[0002] The invention relates to a liquid dispensing device for dispensing a liquid jet surrounded by a jacket-like air flow and expanding fan-shaped in a jet plane, wherein the liquid dispensing device has a jet-generating part with a flat jet nozzle for generating the liquid jet, and wherein the liquid dispensing device has a housing at least partially accommodating the jet-generating part, wherein a channel structure is arranged or formed in the housing, which has a liquid receiving section arranged downstream of the flat jet nozzle for receiving the liquid jet and a liquid dispensing section adjoining the liquid receiving section for dispensing the liquid jet, as well as at least one air intake section, wherein the liquid receiving section is in flow connection with at least one air intake opening via the at least one air intake section,and wherein the liquid discharge section extends to an outlet opening of the housing and widens fan-shaped in the jet plane.,

[0003] Jet-generating parts with a flat jet nozzle for generating a fluid jet that expands fan-shaped in a jet plane are used, for example, as accessories for pressure cleaning devices, particularly for high-pressure cleaning devices, to cover a surface to be cleaned with a fan-shaped fluid jet. Pressurized water, for example, can be used as the fluid. Such flat jet nozzles are known 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 surface to be cleaned. This results in the liquid jet being slowed down and becoming less compact. To counteract this effect, JP 2004 / 223409 A proposes a liquid dispensing device that, in addition to a flat jet nozzle, uses a housing with a through-channel that, among other things, has a liquid receiving section for receiving the liquid jet provided by the flat jet nozzle and a liquid dispensing section adjoining the liquid receiving section for dispensing the liquid jet.The liquid intake section is in flow communication with an air intake opening via at least one air intake channel, and the liquid discharge section extends to an outlet opening of the housing and expands fan-shaped in the jet plane. Under the action of the liquid jet, air is drawn into the liquid intake section via the at least one air intake opening, forming an air jacket surrounding the liquid jet and being discharged together with the liquid jet via the outlet opening. The air jacket surrounding the fan-shaped expanding liquid jet reduces the interaction of the liquid jet with the ambient air.

[0005] The air is sucked into the liquid intake section in the manner of a jet pump by the liquid jet emerging at considerable speed from the nozzle outlet opening of the flat jet nozzle. Along with the air, dirt particles may also penetrate the channel structure of the housing through the at least one air intake opening. This can lead to the channel structure becoming blocked in areas where it has a narrow clearance, or to the channel walls of the channel structure becoming subject to wear due to the abrasion that the dirt particles can cause.

[0006] The object of the present invention is therefore to further develop a liquid dispensing device of the generic type in such a way that the risk of blockage or wear of the channel structure is minimized. This object is achieved according to the invention in a liquid dispensing device of the type mentioned above in that a filter device is arranged at the at least one air intake opening, which filter device has at least one through-opening delimited by an opening edge, wherein the opening edge has at least two opposing edge sections arranged at a distance from one another that is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure.

[0007] According to the invention, a filter device having at least one through-opening is arranged at the at least one air intake opening. Air can be sucked into the channel structure via the at least one through-opening to form an air jacket enveloping the liquid jet. Any dirt particles carried by the air can, however, be at least partially retained, thus counteracting possible abrasion or blockage of the channel structure. The at least one through-opening of the filter device is delimited by an opening edge having at least two opposing edge sections arranged at a distance from one another that is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure.The smallest clear width of the channel structure is understood to mean the smallest extent of the channel structure perpendicular to the flow direction of the fluid flowing through the channel structure. The clear width of the channel structure can vary in the area between the at least one air intake opening and the outlet opening. The risk of the channel structure becoming blocked by penetrating dirt particles exists particularly in the area of ​​the channel structure in which it has its smallest clear width. According to the invention, the at least one through-opening of the filter device is therefore designed such that at least two opposing edge sections of the opening edge of the through-opening are spaced apart by a maximum of 1.0 times the smallest clear width of the channel structure. As a result, a considerable proportion of dirt particles, which pose the greatest risk of blocking the channel structure, can be retained.

[0008] The invention also incorporates the idea that very small dirt particles pose only a low risk of clogging the channel structure and at most exert a minor abrasive effect. This circumstance is taken into account according to the invention in that the distance between at least two opposing edge sections of the through-opening is at least 0.1 times the smallest clear width of the channel structure. Very small dirt particles can therefore pass through the through-opening unhindered. This in turn has the consequence that very small dirt particles are not separated in significant quantities at the filter device and thus do not close the at least one through-opening, which could shorten the service life of the filter device and consequently also the service life of the liquid dispensing device.Due to their low weight, very small dirt particles in particular are carried along by the air drawn in. To prevent such dirt particles from being retained by the filter device and thereby impairing the service life of the filter device, the distance between at least two opposing edge sections of the at least one through-opening is at least 0.1 times the smallest clear width of the channel structure.

[0009] The design of the at least one through-opening such that at least two opposing edge sections of the through-opening are arranged at a distance from one another that is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure therefore makes it possible to minimize the risk of blockage and / or wear of the channel structure while maintaining the longest possible service life of the filter device. The distance between at least two opposing edge sections of the at least one through-opening can in particular be 0.3 times to 1.0 times the smallest clear width of the channel structure, for example 0.5 times to 1.0 times the smallest clear width of the channel structure.The greater the minimum distance between at least two opposing edge sections of the at least one through-opening, the longer the service life of the filter device, since fewer dirt particles are then deposited on the filter device.

[0010] In an advantageous embodiment of the invention, the channel structure has its smallest clear width in the region of the outlet opening of the housing. The clear width of the channel structure is the extent of the channel structure perpendicular to the jet plane in the region of the outlet opening. In such an embodiment of the invention, the extent of the channel structure perpendicular to the jet plane in the region of the outlet opening determines the distance between at least two opposing edge sections of the through-opening of the filter device, in that the distance between the opposing edge sections is at least 0.1 times and at most 1.0 times the distance between two opposing channel wall regions of the channel structure in the outlet opening.

[0011] It can be provided that the smallest clear width of the channel structure is the smallest distance between a bottom wall and a top wall of the liquid dispensing section of the channel structure. As already mentioned, the liquid dispensing section widens in the jet plane up to the outlet opening of the housing. At the same time, the liquid dispensing section can narrow at least over part of its length, in particular over its entire length, perpendicular to the jet plane as it approaches the outlet opening, i.e. the distance perpendicular to the jet plane between a top wall of the liquid dispensing section and a bottom wall of the liquid dispensing section can decrease to a minimum value at least over part of its length.Reducing the distance between the bottom wall and the top wall of the liquid receiving section counteracts an increase in the cross-sectional area of ​​the liquid discharge section, which is caused by the widening of the liquid discharge section in the jet plane as the nozzle approaches the outlet opening. This, in turn, counteracts a reduction in the flow velocity of the air jacket surrounding the liquid jet within the liquid discharge section. The flow velocity of the air jacket depends on the size of the cross-sectional area of ​​the liquid discharge section. The more the cross-sectional area increases with increasing approach to the outlet opening, the more the flow velocity of the air jacket decreases.By narrowing the liquid discharge section perpendicular to the jet plane, an increase in the cross-sectional area caused by the widening of the liquid discharge section in the jet plane can be at least partially compensated. This, in turn, results in less impact on the flow velocity of the air jacket surrounding the liquid jet in the circumferential direction within the liquid discharge section. The reduced impact on the flow velocity of the air jacket, in turn, means that the liquid jet is decelerated less within the liquid discharge section and the compactness of the liquid jet within the liquid discharge section is less impacted.The smallest distance between the bottom wall and the top wall of the liquid dispensing section thus defines the smallest clear width of the channel structure perpendicular to the jet plane, so that in this area there is also a high risk of blockage due to penetrating dirt particles. The distance that at least two opposing edge sections of the at least one through-opening of the filter device have from each other is therefore advantageously at least 0.1 times and at most 1.0 times the smallest distance that the top wall of the liquid dispensing section has from the bottom wall of the liquid dispensing section. In an advantageous embodiment of the invention, the smallest clear width of the channel structure is 1 mm to 6 mm, in particular 1.5 mm to 4 mm, for example 2 mm.

[0012] It is advantageous if the filter device has a plurality of through-openings which are circular, square or slit-shaped, wherein slit-shaped through-openings are preferably rectangular or trapezoidal.

[0013] Slot-shaped through openings preferably extend in the radial direction or in the circumferential direction relative to a central longitudinal axis of the housing.

[0014] It is advantageous if the at least one through-opening has two opposing edge sections which are arranged at a distance from one another of at least 0.2 mm and a maximum of 3 mm, in particular at a distance of 1 mm to 2 mm.

[0015] In a particularly preferred embodiment of the liquid dispensing device according to the invention, the housing surrounds a through-channel which extends from an inlet opening of the housing to the outlet opening of the housing, wherein a holding device is arranged in an inlet section of the through-channel adjoining the inlet opening, on which holding device the jet-generating part is held and which is surrounded in the circumferential direction by an air intake section of the channel structure, wherein the through-channel downstream of the air intake section forms the liquid receiving section of the channel structure and, adjoining thereto, the liquid dispensing section of the channel structure, and wherein a region of the inlet opening surrounding the jet-generating part forms an air intake opening at which a filter element is arranged. It is advantageous if the filter device can be detachably connected to the holding device.For example, it can be provided that the filter device can be locked to the holding device.

[0016] Alternatively or additionally, it can be provided that the filter device can be detachably connected to the housing and / or to the beam generating part.

[0017] In particular, it can be provided that the filter device can be placed on the beam-generating part in a form-fitting manner. For example, the filter device can be pressed onto the beam-generating part.

[0018] In a preferred embodiment of the invention, particularly simple assembly of the filter device is achieved in that the filter device has two filter parts which surround the jet generating part in the region of the inlet opening in the circumferential direction over an angular range of maximum 180°.

[0019] The two filter parts are preferably designed identically. This allows the filter parts to be produced in larger quantities and therefore more cost-effectively.

[0020] Assembly is also simplified if the two filter parts are designed identically.

[0021] The housing of the liquid dispensing device according to the invention preferably has two housing half-shells, to each of which a filter part is formed.

[0022] Alternatively or additionally, the housing may comprise two housing half-shells that clamp the filter device, which is in particular configured in two parts, between them. For example, the filter device may comprise at least one retaining projection that is positively received by complementarily configured recesses in the housing half-shells. In a particularly preferred embodiment of the invention, the filter device comprises a filter surface on which the at least one through-opening is arranged, wherein the filter surface protrudes at least partially from the housing. The filter surface is thus more easily accessible to a user of the liquid dispensing device for cleaning purposes.

[0023] It is particularly advantageous if the filter surface is convex or truncated cone-shaped. This allows the filter surface to be larger with the same outer diameter than with a flat filter surface. The force exerted by the drawn-in air on the filter device is thus distributed over a larger filter surface. This reduces the mechanical stress on the filter device and increases its service life. Furthermore, dirt particles adhering to the filter surface can be removed more easily.

[0024] The filter device can be designed, for example, as a sieve, grid, or perforated plate. This allows for particularly cost-effective production of the filter device.

[0025] The following description of advantageous embodiments of the invention serves to explain it in more detail in conjunction with the drawings. They show:

[0026] Figure 1: a perspective view of a first embodiment of a liquid dispensing device;

[0027] Figure 2: a plan view of the liquid dispensing device from Figure 1;

[0028] Figure 3: a sectional view of the liquid dispensing device taken along line 3-3 in Figure 2;

[0029] Figure 4: a sectional view of the liquid dispensing device taken along line 4-4 in Figure 3; Figure 5: a first perspective view of the liquid dispensing device of Figure 1 in the manner of an exploded drawing;

[0030] Figure 6: a second perspective view of the liquid dispensing device from Figure 1 in the manner of an exploded drawing;

[0031] Figure 7: a sectional view of the liquid dispensing device taken along line 7-7 in Figure 2;

[0032] Figure 8: a sectional view of the liquid dispensing device taken along line 8-8 in Figure 2;

[0033] Figure 9: a perspective view of a filter device of the liquid dispensing device from Figure 1 with a view of an inner side of the filter device;

[0034] Figure 10: a perspective view of the filter device from Figure 9 with a view of an outer side of the filter device;

[0035] Figure 11: a side view of the filter device;

[0036] Figure 12: a perspective view of a second embodiment of a liquid dispensing device;

[0037] Figure 13: a plan view of the liquid dispensing device from Figure 12;

[0038] Figure 14: a perspective view of the liquid dispensing device from Figure 12 in the manner of an exploded view;

[0039] Figure 15: a sectional view of the liquid dispensing device taken along line 15-15 in Figure 13; Figure 16: a perspective view of a filter device of the liquid dispensing device of Figure 12, looking toward an interior of the filter device;

[0040] Figure 17: a perspective view of the filter device from Figure 16 with a view of an outer side of the filter device;

[0041] Figure 18: a perspective view of a third embodiment of a liquid dispensing device;

[0042] Figure 19: a longitudinal sectional view of the liquid dispensing device of Figure 18;

[0043] Figure 20: a perspective view of a filter device of the liquid dispensing device from Figure 18;

[0044] Figure 21: a perspective view of a fourth embodiment of a liquid dispensing device;

[0045] Figure 22: a perspective view of the liquid dispensing device from Figure 21 in the manner of an exploded view.

[0046] In Figures 1 to 11, a first advantageous embodiment of a liquid dispensing device according to the invention for dispensing a liquid jet surrounded by an air flow and expanding in a fan-shaped manner in a jet plane is shown schematically by way of example and is designated overall by the reference numeral 10.

[0047] The liquid dispensing device 10 has a housing 12 formed by a first housing half-shell 14 and a second housing half-shell 16, which, in the illustrated embodiment, are screwed together by means of connecting screws 18. The housing 12 surrounds a through-channel 20 that extends from an inlet opening 22, located on a rear side 24 of the housing 12, to an outlet opening 26, located on a front side 28 of the housing 12 opposite the rear side 24. Starting from the inlet opening 22, the through-channel 20 has an inlet section 30 in which a holding device 32 is arranged.

[0048] In the first exemplary embodiment, the holding device 32 is designed in a shell-like manner and comprises a first partial shell 34 and a partial shell 36, each of which is integrally connected to the first housing half-shell 14 and the second housing half-shell 16 via holding ribs 40 aligned radially with a longitudinal axis 38 of the through-channel 20 and evenly distributed over the circumference of the partial shells 34, 36. This is particularly evident in Figure 6.

[0049] The two partial shells 34, 36 accommodate between them a front region 42 of a jet generating part 44 of the liquid dispensing device 10 facing the outlet opening 26, wherein the jet generating part 44 is held on the two partial shells 34, 36 in a rotationally fixed and axially immovable manner.

[0050] The jet-generating part 44 has a liquid supply member 46, which forms a liquid inlet channel 48 and to which a flat jet nozzle 50 is connected in the direction of the outlet opening 26. Furthermore, the jet-generating part 44 has a nozzle holding member 52, by means of which the flat jet nozzle 50 is secured to the liquid supply member 46.

[0051] In the direction away from the outlet opening 26, the fluid supply member 46 is adjoined by a connecting member 54 of the jet generation part 44, which protrudes from the rear side 24 of the housing 12 and is held on the fluid supply member 46 so as to be rotatable and axially immovable about the longitudinal axis 38 of the through-channel 20. The connecting member 54 has a connecting sleeve 56 with an internal thread 58. The connecting sleeve 56 is surrounded in a rotationally fixed manner by a plastic casing 60, which can be gripped by the user to screw the connecting sleeve 56 to a complementarily designed connecting member of a fluid supply line.

[0052] A jet pipe or a spray gun, for example, can be used as a liquid supply line, which can be supplied with pressurised liquid, in particular pressurised water, from a pressure cleaning device.

[0053] Starting from the connecting element 44, the pressurized liquid can reach the flat jet nozzle 50 via the liquid supply element 46. The flat jet nozzle 50 has a nozzle contour and a nozzle outlet opening designed such that, upon leaving the flat jet nozzle 50, the liquid forms a fan-shaped liquid jet 64 that expands in a jet plane 62. The jet plane 62 and the liquid jet 64 are shown in dashed lines in Figure 4.

[0054] The holding device 32 is surrounded in the inlet section 30 of the through-channel 20 by an annular space 70, which is penetrated in the radial direction by the holding ribs 40. The annular space 70 adjoins, in the axial direction relative to the longitudinal axis 38 of the through-channel 20, a region of the inlet opening 22 surrounding the jet-generating part 44, which forms an air intake opening 72.

[0055] The through-channel 20, in combination with the holding device 32, defines a channel structure 74 of the liquid dispensing device 10, which extends from the air intake opening 72 to the outlet opening 26 and serves to receive air and liquid. The annular space 70 forms an air intake section 76 of the channel structure 74, which adjoins the air intake opening 72 and extends to the nozzle outlet opening of the flat jet nozzle 50. Adjoining the air intake section 76 is a liquid intake section 78 of the channel structure 74, which extends to a constriction 68 of the through-channel 20. Adjoining the liquid intake section 78 is a liquid output section 80 of the channel structure 74. The liquid discharge section 80 extends to the outlet opening 26, widening fan-shaped in the jet plane 62 and increasingly narrowing perpendicular to the jet plane 62 to the outlet opening 26.The jet plane 62 forms a plane of symmetry of the liquid discharge section 80.

[0056] The liquid dispensing section 80 is defined perpendicularly to the jet plane 62 by a bottom wall 82 and a top wall 84, which form two opposing channel wall regions of the channel structure 74. In the jet plane 62, the liquid dispensing section 80 is defined by two opposing side walls 86, 88, which also form two opposing channel wall regions of the channel structure 74.

[0057] As already mentioned, a fan-shaped, expanding liquid jet 64 can be discharged from the flat jet nozzle 50. Under the action of the liquid jet 64, air is sucked into the liquid receiving section 78 via the air intake opening 72 and the adjoining air intake section 76. This air jacket forms an air jacket that surrounds the liquid jet 64 and is discharged together with the liquid jet via the liquid discharge section 80 and the outlet opening 26.

[0058] The air is sucked in like a jet pump by the liquid jet 64 emerging at considerable speed from the nozzle outlet opening of the flat jet nozzle 50. Together with the sucked-in air, dirt particles can under certain circumstances penetrate into the channel structure 74 via the air intake opening 72. This can lead to the channel structure 74 becoming blocked in areas where it has a small clear width, or to the channel walls of the channel structure 74 becoming subject to wear due to the abrasion caused by the dirt particles. To minimize the risk of blockage or wear of the channel structure 74, the liquid dispensing device 10 has a filter device 90 arranged at the air intake opening 72.In the first exemplary embodiment of the invention, the filter device 90 has two identically designed filter parts 92, 94, each of which is semi-annular and surrounds the jet-generating part 44 in the region of the inlet opening 22 in the circumferential direction over an angular range of 180°. The filter parts 92, 94 each have a locking hook 96 or 97, with the aid of which they can be locked to a partial shell 34 or 36 of the holding device 32. For this purpose, the partial shells 34, 36 each have a locking receptacle 98 or 99 in the form of an opening into which a locking hook 96, 97 can engage. This is particularly clear from Figures 5 and 8.

[0059] The two filter parts 92, 94 form a filter surface 100 on which a plurality of through-openings 102 are arranged. The through-openings 102 are slit-shaped and oriented radially relative to the longitudinal axis 38 of the through-bore 20. The through-openings 102 are each delimited by an opening edge 104, which is essentially trapezoidal in shape and has two opposing elongated edge sections 106, 108 and two opposing shorter edge sections 110, 112. This is clearly shown, for example, in Figure 10.

[0060] The intake air can flow through the through-openings 102 virtually unhindered, whereas dirt particles entrained by the air are at least partially retained. As already mentioned, dirt particles penetrating the channel structure 74 can, under certain circumstances, lead to a blockage of the channel structure 74 or to the channel walls of the channel structure 74 being subject to severe abrasion. The risk of blockage of the channel structure 74 exists in particular in regions of the channel structure 74 in which it has its smallest clear width, i.e. in a region in which the channel structure 74 has its smallest extent perpendicular to the flow direction of the fluid flowing through the channel structure 74. In the illustrated embodiment, the channel structure 74 has its smallest clear width in the outlet opening 26 in the form of the distance between the bottom wall 82 and the ceiling wall 84.In the embodiment shown, this distance is 2 mm.

[0061] To counteract possible blockage of the outlet opening 26, the opposing elongated edge sections 106, 108 of the opening edge 104 of the through-openings 102 are spaced apart by a distance of at least 0.1 times and a maximum of 1.0 times the smallest clear width of the channel structure 74. In the illustrated embodiment, the distance between the elongated edge sections 106, 108 is 2 mm at the outer end of the elongated edge sections 106, 108 and 1.3 mm at the inner end of the elongated edge sections 106, 108, wherein the outer and inner ends are relative to the longitudinal axis 38.The distance between the elongated edge sections 106, 108 is dimensioned such that the penetration of dirt particles whose extent is greater than the distance between the bottom wall 82 and the top wall 84 in the region of the outlet opening 26 is prevented, but that very small dirt particles, which pose only a very low risk of clogging the channel structure 74 and at most exert a very low abrasive effect, can pass through the filter device 90. This prevents very small dirt particles from clogging the filter device 90 within a short period of time and thereby shortening the service life of the filter device 90 and thus also of the liquid dispensing device 10.

[0062] The distance between the opposing shorter edge sections 110, 112 is greater than that between the opposing elongated edge sections 106, 108. The distance between the shorter edge sections 110, 112 can, for example, be at least twice as large as the distance between the elongated edge sections 106, 108. In the first embodiment shown by way of example, the distance between the shorter edge sections 110, 112 is 5 mm to 7 mm.

[0063] To easily detach larger dirt particles that settle on the filter device 90, the filter surface 100 of the filter device 90 is inclined relative to the longitudinal axis 38 of the passage channel 20 and protrudes at least partially from the housing 12, making it more easily accessible to the user. In the illustrated embodiment, the filter surface 100 is frustoconical or convex, curved outward in the direction away from the housing 12.

[0064] On its outer side 114 facing away from the housing 12, the filter device 90 has a plurality of radially aligned reinforcing ribs 116, which have a radially outer end portion 118 that projects radially beyond a circumferential outer edge 120 of the filter device. Using the outer end portions 118, the filter device 90 can be placed on the edge of the inlet opening 22 and supported against this edge.

[0065] To facilitate the assembly of the two filter parts 92, 94 on the air intake opening 72, the two filter parts 92, 94 each have a plurality of guide ribs 122 on their inner side 121 facing the housing, which are aligned substantially parallel to the respective locking hooks 96. This is particularly evident in Figure 9.

[0066] Figures 12 to 17 schematically illustrate a second advantageous embodiment of a liquid dispensing device according to the invention for dispensing a liquid jet surrounded by a jacket-like air flow and expanding fan-shaped in a jet plane, and is designated overall by the reference numeral 150. The liquid dispensing device 150 is largely identical in design to the liquid dispensing device 10 described above with reference to Figures 1 to 11. For identical components, the same reference numerals are therefore used in Figures 12 to 17 as in Figures 1 to 11, and with regard to these components, reference is made to the above explanations to avoid repetition.

[0067] The liquid dispensing device 150 also has a housing 12 with a first housing half-shell 14 and a second housing half-shell 16, which are screwed together by means of connecting screws 18. The housing 12 surrounds a through-channel 20, which extends from an inlet opening 22 to an outlet opening 26 and, in combination with a holding device 32, forms a channel structure 74, as already explained above.

[0068] In contrast to the liquid dispensing device 10, the liquid dispensing device 150 uses a filter device 152 that is designed as a single piece and has a central opening 151 and a plurality of slot-shaped through-openings 154 that extend circumferentially relative to the longitudinal axis 38 of the housing 12. The through-openings 154 are each delimited by an opening edge 156 that has two opposing, circumferentially extending, elongated edge sections 158, 160 that are connected to one another via two opposing, radially aligned, shorter edge sections 162, 164. The elongated edge sections 162, 164 are arranged at a distance from one another that is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure 74.The shorter edge sections 162, 164 are arranged at a distance from one another that is greater than the distance between the elongated edge sections 162, 164. In the illustrated embodiment, the distance between the shorter edge sections is at least twice the distance that the elongated edge sections are from one another. As with the liquid dispensing device 10 explained above, the channel structure 74 in the liquid dispensing device 150 also has its smallest clear width in the region of the outlet opening 26 in the form of the distance between the bottom wall 82 and the top wall 84, wherein the distance is 2 mm. The distance between the opposing elongated edge sections 158, 160 is also 2 mm, but could also be selected to be smaller, but in any case is at least 0.2 mm.

[0069] During assembly of the liquid dispensing device 150, the filter device 152 can be placed in the axial direction onto the jet-generating part 44, starting from the flat jet nozzle 50, wherein, in an end position, it assumes a position immediately upstream of the connecting member 54. The two housing half-shells 14, 16 can then be joined and screwed together, wherein the housing half-shells 14, 16 positively accommodate two diametrically opposed projections 166, 168 in the region of the inlet opening 22, which projections are arranged on the inner side 170 of the filter device 152 facing away from the connecting member 54. This is particularly clear from Figures 15 and 16. By means of the projections 166, 168, the filter device 152 is held axially immovably and rotationally fixed to the housing half-shells 14, 16 of the liquid dispensing device 150.

[0070] In addition to the projections 166, 168, an annular collar 172 is arranged on the inner side 170 of the filter device 152, which collar is aligned concentrically with the longitudinal axis 38 and surrounds the central opening 151. The collar 172 has two diametrically opposed, axially aligned retaining lugs 174, 176, which, when the two housing half-shells 14, 16 are joined together, assume a position between the two partial shells 34, 36 of the holding device 32, thereby additionally securing the filter device 152.By means of the filter device 152, in accordance with the filter device 90 explained above, the risk of blockage or wear of the channel structure 74 of the liquid dispensing device 150 can be kept to a minimum, wherein the minimum distance between the elongated edge sections 158, 160 of the through-bores 154 ensures that very small dirt particles are not retained to a large extent by the filter device 152 and consequently do not deposit in large quantities on the filter device 152, so that the service life of the filter device 152 is not impaired by very small dirt particles.

[0071] Figures 18, 19 and 20 schematically illustrate a third advantageous embodiment of a liquid dispensing device according to the invention for dispensing a liquid jet surrounded by a jacket-like air flow and expanding fan-shaped in a jet plane, and is designated overall by the reference numeral 200. The liquid dispensing device 200 is largely identical in design to the liquid dispensing device 10 described above with reference to Figures 1 to 11. For identical components, the same reference numerals are therefore used in Figures 18, 19 and 20 as in Figures 1 to 11, and with regard to these components, reference is made to the above explanations to avoid repetition.

[0072] The liquid dispensing device 200 also has a housing 12 with a first housing half-shell 14 and a second housing half-shell 16, which are screwed together by means of connecting screws 18. The housing 12 surrounds a through-channel 20, which extends from an inlet opening 22 to an outlet opening 26 and, in combination with a holding device 32, on which a jet-generating part 44 is held, forms a channel structure 74 having an air intake section 76, which adjoins an air intake opening 72 circumferentially surrounding the jet-generating part 44 in the region of the inlet opening 22. The liquid dispensing device 200 has a filter device 202, which is designed in one piece in the form of a perforated plate 204. The perforated plate 204 has a central opening 203 and a plurality of through openings 206, each of which is delimited by a circular opening edge 208.The opening edge 208 has a plurality of diametrically opposed edge sections 210, 212, each spaced apart by a distance corresponding to the diameter of the circular through-openings 206. In the preferred embodiment shown, the diameter and thus the spacing of the opposing edge sections 210, 212 is 2 mm and is thus 1.0 times the smallest clear width of the channel structure 74 of the liquid dispensing device 200, wherein the smallest clear width in the region of the outlet opening 26 is the distance between the bottom wall 82 and the top wall 84, which is also 2 mm in the liquid dispensing device 200.

[0073] However, the diameter of the circular through-openings 206 can also be selected to be smaller, but not less than 0.2 mm, ensuring that very small dirt particles are not retained by the filter device 202 and consequently do not deposit on the filter device 202 to a large extent, thus impairing its service life. On the other hand, selecting a diameter of the through-openings 206 of a maximum of 1.0 times the smallest clear width of the channel structure 74 ensures that large dirt particles, which pose the greatest risk of clogging the channel structure 74, are retained by the filter device 202.

[0074] To fix the filter device 202 to the inlet opening 22 of the housing 12 of the liquid dispensing device 200, the filter device 202 can be pressed onto the liquid supply member 46 during assembly of the jet-generating part 44, whereby it comes into contact with the rear end of the holding device 32 facing away from the outlet opening 26. The connecting member 54 can then be connected to the liquid supply member 46. The jet-generating part 44 can then be inserted with its front region 42 into one of the two partial shells 34, 36 of the holding device 32, and subsequently the two housing half-shells 14, 16 can be joined together, whereby the front region 42 of the jet-generating part 44 assumes a position between the two partial shells 34, 36 of the holding device 32.

[0075] Figures 21 and 22 schematically illustrate a fourth advantageous embodiment of a liquid dispensing device according to the invention for dispensing a liquid jet surrounded by a jacket-like air flow and expanding fan-shaped in a jet plane, and is designated overall by the reference numeral 230. The liquid dispensing device 230 is largely identical in design to the liquid dispensing device 10 described above with reference to Figures 1 to 11. For identical components, the same reference numerals are therefore used in Figures 21 and 22 as in Figures 1 to 11, and with regard to these components, reference is made to the above explanations to avoid repetition.

[0076] The liquid dispensing device 230 also has a housing 12 with a first housing half-shell 14 and a second housing half-shell 16, which are screwed together by means of connecting screws 18. The housing 12 surrounds a through-channel 20 that extends from an inlet opening 22 to an outlet opening 26 and, in combination with a holding device 32 to which a jet-generating part 44 is fixed, forms a channel structure 74 that adjoins an air intake opening 72 that circumferentially surrounds the jet-generating part 44 in the region of the inlet opening 22. A filter device 232, which has two filter parts 234, 236, is arranged at the air intake opening 72 of the liquid dispensing device 230. The filter parts 234, 236 are semi-annular and surround the jet generating part 44 in the region of the inlet opening 22 in the circumferential direction over an angular range of 180°.In contrast to the filter parts 92, 94 described above with reference to the liquid dispensing device 10, the filter parts 234, 236 of the liquid dispensing device 230 are each molded onto one of the two housing half-shells 14, 16, so that together with a housing half-shell 14 or 16 they each form a one-piece plastic molded part.

[0077] The filter parts 234, 236 have a plurality of slot-shaped through-openings 238, which are configured in the same way as the through-openings 102 of the liquid dispensing device 10. To avoid repetition, reference is made to the above explanations in this regard. The through-openings 238 also have opposing, elongated edge sections, the spacing of which is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure 74 of the liquid dispensing device 230.

[0078] The liquid dispensing device 230 can also be used to dispense a fan-shaped, widening liquid jet that is surrounded by a jacket-like air flow, whereby the risk of blockage or wear of the channel structure 74 of the liquid dispensing device 230 can be kept low without the service life of the liquid dispensing device being significantly impaired, as already explained above with reference to the liquid dispensing devices 10, 150 and 200.

Claims

P A T E N T A N S P R Ü C H E 1. Liquid dispensing device for dispensing a liquid jet which is surrounded by an air flow and widens in a fan-shaped manner in a jet plane, wherein the liquid dispensing device (10; 150; 200; 230) has a jet generating part (44) with a flat jet nozzle (50) for generating the liquid jet (64), and wherein the liquid dispensing device (10; 150; 200;230) has a housing (12) at least partially accommodating the jet generating part (44), wherein a channel structure (74) is arranged or formed in the housing (12), which has a liquid receiving section (78) arranged downstream of the flat jet nozzle (50) for receiving the liquid jet (64) and a liquid discharge section (80) adjoining the liquid receiving section (78) for discharging the liquid jet (64), as well as at least one air intake section (76), wherein the liquid receiving section (78) is in flow connection with at least one air intake opening (72) via the at least one air intake section (76), and wherein the liquid discharge section (80) extends up to an outlet opening (26) of the housing (12) and widens out in a fan shape in the jet plane (72), characterized in that a filter device (90; 152; 202;232) is arranged, which has at least one through-opening (102; 154; 206; 238) delimited by an opening edge (104; 156; 208), wherein the opening edge (104; 156; 208) has at least two opposing edge sections (106, 108; 158, 160; 210, 212) which are arranged at a distance from one another which is at least 0.1 times and at most 1.0 times the smallest clear width of the channel structure (74); 2. Liquid dispensing device according to claim 1, characterized in that the channel structure (74) has its smallest clear width in the region of the outlet opening (26).

3. Liquid dispensing device according to claim 1 or 2, characterized in that the smallest clear width of the channel structure (74) is the smallest distance that a bottom wall (82) occupies from a top wall (84) of the liquid dispensing section (80).

4. Liquid dispensing device according to one of the preceding claims, characterized in that the smallest clear width of the channel structure (74) is 1 mm to 6 mm, in particular 1.5 mm to 4 mm.

5. Liquid dispensing device according to one of the preceding claims, characterized in that the filter device (90; 152; 202; 232) has a plurality of through openings (102; 154; 206; 238) which are circular, square or slit-shaped.

6. Liquid dispensing device according to one of the preceding claims, characterized in that the at least one through-opening (102; 154; 206; 238) has two opposing edge sections (106, 108; 158, 160; 210, 212) which are arranged at a distance from one another of at least 0.2 mm and a maximum of 3 mm, in particular 1 mm to 2 mm.

7. Liquid dispensing device according to one of the preceding claims, characterized in that the housing (12) surrounds a through-channel (20) which extends from an inlet opening (22) of the housing (12) to the outlet opening (26) of the housing (12), wherein in a channel adjoining the inlet opening (22) a holding device (32) is arranged in the inlet section (30) of the through-channel (20), on which holding device the jet-generating part (44) is held and which is surrounded in the circumferential direction by an air intake section (76) of the channel structure (74), wherein the through-channel (20) downstream of the air intake section (76) forms the liquid receiving section (78) of the channel structure (74) and, adjoining thereto, the liquid discharge section (80) of the channel structure (74), and wherein a region of the inlet opening (22) surrounding the jet-generating part (44) forms an air intake opening (72) on which a filter device (90; 152; 202; 232) is arranged.

8. Liquid dispensing device according to claim 7, characterized in that the filter device (90; 152) is detachably connectable to the holding device (32).

9. Liquid dispensing device according to one of the preceding claims, characterized in that the filter device (202) is detachably connectable to the housing (12) and / or to the jet generating part (44).

10. Liquid dispensing device according to one of the preceding claims, characterized in that the filter device (90; 232) has two filter parts (92, 94; 234, 236) which surround the jet generating part (44) in the region of the inlet opening (22) in the circumferential direction over an angular range of a maximum of 180°.

11. Liquid dispensing device according to claim 10, characterized in that the two filter parts (92, 94; 234, 236) are designed identically.

12. Liquid dispensing device according to claim 10 or 11, characterized in that the housing (14) has two housing half-shells (16, 18), to each of which a filter part (234, 236) is formed.

13. Liquid dispensing device according to claim 10 or 11, characterized in that the housing (12) has two housing half-shells (14, 16) which clamp the filter device (152) between them.

14. Liquid dispensing device according to one of the preceding claims, characterized in that the filter device (90) has a filter surface (100) on which the at least one through-opening (102) is arranged, wherein the filter surface (100) protrudes at least partially from the housing (12).

15. Liquid dispensing device according to claim 14, characterized in that the filter surface (100) is convexly curved or frustoconical.

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