NOZZLE UNIT, LIQUID DISPENSER WITH SUCH A NOZZLE UNIT AND METHOD FOR MANUFACTURING SUCH NOZZLE UNITS

Description

FIELD OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to a method for producing a nozzle unit for a liquid dispenser.

[0002] A nozzle unit within the meaning of the invention is a component of a liquid dispenser located at the end of a liquid path along which the liquid is discharged from a liquid reservoir of the liquid dispenser. Typically, such a nozzle unit is used to generate a spray jet, which is then delivered, for example, into a mouthpiece for inhalation.

[0003] The nozzle unit is inserted into the housing of the liquid dispenser. The outer surfaces of the nozzle unit used for assembly are formed by a plastic carrier. This carrier is penetrated by a nozzle channel from an inlet side, from which the liquid flows, to an outlet side, where the liquid is dispensed.

[0004] Typically, a nozzle plate arrangement is arranged within the nozzle channel, primarily a nozzle plate arrangement with a multitude of very small nozzle openings through which pressurized liquid is forced. This breaks the liquid into small or tiny droplets, creating, for example, a throat- or lung-penetrating aerosol.

[0005] The nozzle unit with the plastic carrier not only serves to arrange the nozzle plate arrangement in the flow path, but can also be a carrier of a filter arrangement that frees the outflowing liquid in front of the nozzle plate arrangement from components of the liquid that could block the nozzle openings and thus prevent the intended discharge.

[0006] An exemplary nozzle unit similar to the nozzle unit according to the invention in terms of its intended use is known from WO 2015 / 194962 A1. The nozzle unit presented therein has a nozzle plate and various filter surfaces that are held in a nozzle channel by thermoplastic deformation.

[0007] Document US 3756462 A describes a microemitter device for pressure vessels that enables the controlled ejection of liquids. It uses a perforated membrane to atomize liquid droplets.

[0008] Document EP 2890502 B1 describes a foam spray device that produces a foam consistency. It uses a squeezable container and a special mechanism with valves, membranes, and mesh inserts to mix air and liquid. TASK AND SOLUTION

[0009] The object of the invention is to provide a manufacturing method suitable for producing a nozzle unit with high reliability with regard to the discharge characteristics.

[0010] The method according to the invention serves to introduce a nozzle plate arrangement into the dosing channel within the scope of the production of a nozzle unit.

[0011] According to the invention, the nozzle plate assembly is inserted using an assembly tool. This assembly tool has an outer contour that is oversized relative to the nozzle channel, so that the assembly tool can elastically expand the nozzle channel by being inserted into the nozzle channel and applying force to a nozzle channel wall there. An end face of the assembly tool is larger than an outer contour of the nozzle plate assembly.

[0012] To install the nozzle plate assembly, the plastic carrier is first placed in a defined mounting position, preferably with the output side of the plastic carrier facing downward. Such a defined mounting position can be absolutely stationary or fixed to a mounting carrier that is movable as a whole.

[0013] In the aforementioned assembly position, the nozzle plate assembly is first inserted into the nozzle channel from the inlet side and in a joining direction toward the outlet side. For this purpose, the nozzle channel preferably has an inlet-side section whose cross-section is larger than the outer contour of the nozzle plate assembly, so that the nozzle plate assembly can be inserted into the nozzle channel without deforming it.

[0014] In a particularly simple and preferred embodiment, the nozzle plate arrangement can be formed as a one-piece nozzle plate and can be punched out of a carrier plate by means of a punching process immediately before insertion into the nozzle channel. Direct insertion here means that punched-out nozzle plates are not first brought together to be inserted into plastic carriers in a later process step. Instead, according to this preferred procedure, only punched-out nozzle plate arrangements are handled individually. The risk of contamination or damage to the nozzle plate arrangement is therefore very low. As an alternative to a nozzle plate arrangement consisting only of the nozzle plate, this can additionally have a carrier ring, as explained below.

[0015] After the nozzle plate assembly, or in the case of a simple design, the one-piece nozzle plate, has been inserted into the nozzle channel, the assembly tool is then inserted into the nozzle channel from the inlet side in the joining direction, essentially following the nozzle plate assembly. This sequence can also be achieved by first placing the nozzle plate on the front side of the assembly tool and then inserting the assembly tool, together with the nozzle plate, into the nozzle channel.

[0016] As the assembly tool is progressively inserted into the nozzle channel in the joining direction, the assembly tool increasingly comes into contact with the nozzle channel wall and partially expands it elastically with its outer contour. This expansion allows the nozzle plate arrangement to penetrate deeper and deeper into the nozzle channel, which preferably already tapers in the relaxed state, without being damaged in the edge area. As the assembly tool is increasingly pressed in, the nozzle plate arrangement can come into contact with the front side of the assembly tool and can essentially be pushed by it. Such contact is not absolutely necessary, however. Instead, the nozzle plate arrangement can slide deeper and deeper into the nozzle channel as it expands, for example solely due to its weight, while there is no contact between the nozzle plate arrangement and the front side of the assembly tool at certain times or continuously.In the case of a nozzle plate arrangement with a carrier ring, the assembly tool preferably presses directly against this carrier ring.

[0017] When the relative movement between the plastic carrier and the assembly tool ends, the nozzle plate assembly has reached its end position.

[0018] The assembly tool is then withdrawn from the nozzle channel in the opposite direction to the joining direction. The nozzle plate assembly essentially remains in its final position, although this position may still change slightly if the nozzle plate assembly is also pushed back a small distance in the opposite direction to the joining direction under the influence of the nozzle channel's retraction. The retraction of the nozzle channel upon retraction of the assembly tool ultimately results in the nozzle plate assembly being held by the nozzle channel wall, in particular by two nozzle channel sections on either side of the nozzle plate, whose remaining clear cross-section after retraction is smaller than the outer contour of the nozzle plate assembly.

[0019] In the area of ​​the nozzle plate assembly, it presses from the inside against the retractable wall of the nozzle channel, thus preventing its complete retraction. The nozzle plate assembly is thus essentially clamped in the nozzle channel. Downstream and upstream of the nozzle plate assembly, the retractable wall preferably slightly constricts the nozzle channel, so that the nozzle plate assembly is held in place with a positive fit after the assembly tool is removed.

[0020] Although the method can in principle also be used for inserting nozzle plate assemblies into cylindrical nozzle channels, it is advantageous if the nozzle channel tapers in the joining direction, i.e., from the inlet side to the outlet side. In particular, the nozzle channel preferably has at least one conical section, which preferably has a cross-section at its end facing the inlet side that is larger than the outer contour of the assembly tool, and at its end facing the outlet side that has a cross-section that is smaller than the outer contour of the assembly tool.

[0021] When the assembly tool is inserted into the nozzle channel, its end face and / or outer contour in the aforementioned conical section comes into contact with the nozzle channel wall, expanding it as it continues to move. The conical shape leads to a highly reproducible engagement of the nozzle plate assembly into a section of the nozzle channel that is continuously expanding as a result of the assembly tool. A preferred opening angle of the conical section is between 5° and 15°.

[0022] As the assembly tool is progressively inserted into the nozzle channel in the joining direction, an auxiliary tool can be inserted into the nozzle channel from the exit side, aligned with the assembly tool. This auxiliary tool can be withdrawn, particularly in the joining direction, while the assembly tool is still moving into the nozzle channel in the joining direction.

[0023] Depending on its design and movement profile, the auxiliary tool can prevent the nozzle plate from accidentally moving too far into the nozzle channel. It can also help maintain a precise end-of-stroke position and / or proper alignment.

[0024] In a special embodiment of the method, the end face of the assembly tool and / or one end face of the auxiliary tool rests against the nozzle plate assembly during the continued insertion of the assembly into the nozzle channel. If both end faces rest against the assembly, the position of the assembly in the nozzle channel can be precisely controlled.

[0025] Furthermore, the non-planar design of the end faces of the assembly tool and / or the auxiliary tool can cause deformation of the nozzle plate assembly. In particular, the end face of the assembly tool can have a convexly curved shape, and the end face of the auxiliary tool can have a concavely curved shape. As the assembly tool is inserted into the nozzle channel, the end faces thus shaped elastically and / or plastically press the nozzle plate assembly into a curved shape.

[0026] Such a curved shape offers the advantage that the previously parallel nozzle openings are angled toward each other and, in particular, aligned in a diverging manner. This is advantageous in many applications, as it creates a wider, fanned-out spray jet.

[0027] In addition, elastic deformation of the nozzle plate caused by the assembly tool and / or the auxiliary tool, and in particular by both tools together, leads to a temporary reduction in the diameter of the nozzle plate assembly, allowing the nozzle plate assembly to engage more deeply in a tapered nozzle channel. As soon as the force applied to the nozzle plate by the assembly tool and / or the auxiliary tool is removed, a particularly strong deformation of a surrounding annular area occurs, resulting in a high positional stability of the nozzle plate assembly.

[0028] Due to the typically occurring elastic deformation of a ring region surrounding the nozzle plate arrangement and the design of the individual components, which are also explained in more detail below, the method according to the invention results in a high level of tightness and positional stability of the nozzle plate arrangement without any thermal post-treatment. Nevertheless, it can be advantageous if the nozzle plate arrangement, after reaching its final position and after removal of the assembly tool, is heated to the softening temperature of the plastic of the plastic carrier, in particular to at least 100°C, so that the tightness in the edge region of the nozzle plate arrangement is further improved. However, this heating preferably does not take place to an extent that would result in a complete reduction of the elastic deformation in the aforementioned ring region. The heating can be achieved, for example, by means of a laser or by induction.

[0029] A nozzle unit manufactured by the method comprises a plastic carrier through which a nozzle channel extends from an inlet side to an outlet side. The plastic carrier preferably has an outer shape that is coaxial with the nozzle channel and rotationally symmetrical to facilitate handling during assembly into a liquid dispenser.

[0030] A nozzle plate arrangement is arranged in the nozzle channel of the nozzle unit. This arrangement has a plurality of nozzle openings, preferably at least 10, particularly preferably at least 30. The average diameter of these nozzle openings is preferably between 1 µm and 100 µm, particularly preferably between 2 µm and 10 µm. In the case of non-circular nozzle openings, these diameter specifications refer to imaginary round nozzle openings with an internal cross-section of the same size as the non-circular nozzle openings.

[0031] The nozzle plate arrangement is inserted into the plastic carrier under elastic deformation of the latter, so that at least one ring region of the plastic carrier surrounding the nozzle plate arrangement is in an elastically compressed state and thereby enables a secure and tight fastening of the nozzle plate arrangement.

[0032] In a preferred design, the nozzle plate arrangement is formed in one piece, in particular in the form of a flat nozzle plate with a substantially constant thickness. The nozzle openings are provided in this nozzle plate. The outer contour of this nozzle plate acts on the compressed annular region of the plastic carrier, thereby deforming it. The nozzle plate preferably has an edge region in which the thickness of the nozzle plate tapers in order to act on the annular region with a particularly narrow ridge and thereby penetrate into the inner surface of the annular region. This ensures very good hold. Despite the penetration, an elastic compression of the annular region remains, which ensures long-term tightness and thus prevents deterioration of the spray pattern or penetration of contaminants, even during long storage periods.

[0033] In addition to the described one-piece design, other designs of the nozzle plate arrangement may also be expedient depending on the intended application and type of assembly. This includes, in particular, a design of the nozzle plate arrangement with a flat nozzle plate and, in addition, a support frame attached to it. The support frame has a central opening that leaves the nozzle openings of the nozzle plate free. The support frame itself can be the part of the nozzle plate arrangement that applies radial outward force to the annular region. However, even when a support frame is present, it is preferably exclusively or at least predominantly the nozzle plate that acts directly on the annular region with its preferably thin-walled outer contour. In this case, the support frame therefore has an outer contour that is sufficiently small that the outer contour of the nozzle plate can elastically deform the annular region.

[0034] The support frame can facilitate the handling of nozzle plate assemblies prior to assembly, as well as the assembly itself. By attaching it upstream of the nozzle plate, it can serve, in particular, to absorb the force directly coupled into the nozzle plate by the described assembly tool.

[0035] If a support frame is provided, it is preferably made of plastic. The nozzle plate is preferably made of a metallic material, preferably nickel. The additive manufacturing process known as electroforming is particularly suitable as a manufacturing process. In this process, these nozzle openings can be created in a single-step process. Alternatively, nozzle openings can also be created subsequently using a laser. In addition to metallic nozzle plates, nozzle plates made of other materials, such as silicon nozzle plates, can also be used.

[0036] In the simplest case, the nozzle plate has sufficient inherent stability to remain flat even under the influence of the force generated by the ring area. However, a design in which the nozzle plate has a curved shape can also be advantageous. This curved shape can be created by plastic deformation, particularly during the assembly process described above or even before assembly. However, depending on the type of material used for the nozzle plate, the curved shape can also be created by elastic deformation and a resulting residual stress state.

[0037] The nozzle channel preferably has a rotationally symmetrical shape. The nozzle plate assembly also preferably has a round outer contour, as this simplifies assembly and promotes a tight connection with the annular area.

[0038] At its end facing the inlet side, the nozzle channel preferably has a clear cross-section that is larger than the outer contour of the nozzle plate assembly. This significantly simplifies assembly. Furthermore, the large cross-section or a recess surrounding the nozzle channel is advantageous for providing an upstream filter, as will be explained below.

[0039] For ease of assembly, the nozzle channel preferably has a tapered shape. In particular, the nozzle channel preferably has at least one conical section with an opening angle between 5° and 15°. A conical section with this pitch is very well suited for assembly using the assembly tool described above.

[0040] The nozzle channel preferably has a plurality of sections, each of which is conically shaped but has different opening angles. In particular, in addition to the aforementioned section with an opening angle between 5° and 15°, there is another section with a larger opening angle. The end position of the nozzle plate assembly is preferably located in this area. The larger opening angle improves the accuracy of maintaining the intended end position of the nozzle plate assembly, i.e., its installation position, as well as the reproducibility of this end position in mass production.

[0041] Downstream of the nozzle plate assembly, the nozzle channel preferably tapers further, so that the nozzle plate assembly is followed by an inwardly facing retaining region of the nozzle channel, the inside cross-sectional diameter of which is at least 10% smaller than the diameter of the nozzle plate assembly. In a preferred embodiment, the outer contour of the nozzle plate assembly is held circumferentially by a retaining region tapered to this extent relative to the outer contour. The retaining region secures the nozzle plate arrangement, ensuring that during assembly or handling during production, as well as during use, the nozzle plate assembly cannot be forced out of the nozzle channel in the direction of flow, even under particular mechanical stress such as fluid pressure peaks.

[0042] To achieve a particularly advantageous connection between the nozzle plate arrangement and the plastic carrier in terms of stability and tightness in the edge region, the plastic carrier is formed in the deformed annular region surrounding the nozzle plate in its final position by a tubular wall surrounding the nozzle channel. The wall thickness of this wall, in the non-deformed state, is at least partially between 10% and 80% of the clear width of the nozzle channel at the nozzle plate, preferably between 20% and 40%. The outer diameter of the tubular nozzle channel wall is preferably between 3 mm and 15 mm. The wall thickness is preferably between 10% and 30% of this outer diameter.

[0043] The said plastic carrier of a nozzle unit according to the invention, which has a nozzle plate arrangement and / or a filter of the type described, is particularly preferably made of PET.

[0044] A nozzle unit of the type described is intended for use in a liquid dispenser. Such a liquid dispenser can be designed primarily for dispensing cosmetic or pharmaceutical liquids. In the case of pharmaceutical liquids, these can particularly be those that are inhaled and are nebulized for this purpose using the nozzle unit.

[0045] It usually comprises a liquid reservoir and a housing into which the nozzle unit of the type described is inserted in order to discharge the liquid pumped from the liquid reservoir through the nozzle unit.

[0046] The liquid dispenser is preferably a small, portable liquid dispenser with a liquid reservoir whose maximum volume is between 10 ml and 1000 ml, preferably between 50 ml and 250 ml.

[0047] The fluid can be pumped from the fluid reservoir to the nozzle unit, for example, via a preferably manually operated pumping device. Alternatively, the fluid reservoir can be designed as a pressure reservoir in which the fluid is stored under pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Further advantages and aspects of the invention emerge from the claims and from the following description of preferred embodiments of the invention, which are explained below with reference to the figures. Fig. 1 shows a liquid dispenser according to the invention, which exemplifies a common use of a nozzle unit according to the invention. Fig. 2 bis 4 show in an exploded view, a single part view and a sectional view a first embodiment of a nozzle unit according to the invention and its individual parts. Fig. 4A bis 4D show details and detailed variants of Fig. 4 . Fig. 5A bis 5G show a first partial process for producing the nozzle unit of the Fig. 2 bis 4 , in which a nozzle plate arrangement is inserted into the nozzle channel of the nozzle unit. Fig. 6A bis 6C illustrate a second sub-process for manufacturing the nozzle unit of the Fig. 2 bis 4 , during which a filter is attached to the nozzle unit. Fig. 7 und 8 show a second embodiment of a nozzle unit according to the invention in a sectional view and an exploded view. Fig. 9 bis 11 show further embodiments of a nozzle unit according to the invention, which have an additional clamping element for fastening the filter. Fig. 12 and 13 show an embodiment of the nozzle unit with a curved nozzle plate and the method for inserting this nozzle plate into the nozzle channel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] Fig. 1 shows a liquid dispenser 100 with a nozzle unit 10 according to the invention. This liquid dispenser 100 is to be understood as an exemplary liquid dispenser for a nozzle unit 10. Many other designs of liquid dispensers using nozzle units 10 according to the invention are also conceivable.

[0050] The liquid dispenser 100 of the Fig. 1 has a pressure accumulator 102 in which liquid is stored prior to dispensing. A dispensing head with a housing 104 is attached to this pressure accumulator 102. This dispensing head has a base 112 and an actuating pushbutton 110 that can be depressed relative to it. When this actuating pushbutton 110 is depressed, it acts on an outlet valve 108 of the pressure accumulator 102, so that liquid flows into the dispensing head and reaches the nozzle unit 10. Downstream of the nozzle unit 10, an outlet piece 106 is provided, here exemplarily in the form of a mouthpiece 106. By means of the nozzle unit 10, the inflowing liquid is brought into the form of a spray jet, which is discharged into the outlet piece 106 and can be inhaled by a user.

[0051] The Fig. 2 bis 4 and 4A to 4D initially illustrate the structure of a nozzle unit 10 according to the invention using a first exemplary embodiment including variants.

[0052] Fig. 2 shows the individual components in an exploded view.

[0053] The nozzle unit 10 has a plastic carrier 20 as a supporting component, which has approximately the shape of a cylinder hat with a brim section 28 and a cylinder section 29. A nozzle channel 30 penetrates the plastic carrier from an inlet side 10A to an outlet side 10B.

[0054] A nozzle plate assembly 50 and a filter 80 are inserted or attached from an input side 10A. In the embodiment of the Fig. 2 bis 4 The nozzle plate assembly 50 is formed solely by a thin nozzle plate 51. This nozzle plate 51 contains a plurality of nozzle openings 52 arranged in a matrix-like configuration. The filter 80 is applied, in a manner explained in more detail below, to an end face 20A of the plastic carrier 20 facing toward the inlet side 10A.

[0055] Fig. 3 shows the plastic carrier 20 from the opposite side, i.e. the inlet side 10A of the plastic carrier 20. Here it can be seen that on the inside of the circumferential end face 20A there is a recess 24 surrounding the nozzle channel 30, into which support ribs 26 protrude from the outside.

[0056] Referring to Fig. 4 The structure of the nozzle unit 10 is shown in the assembled state. It can be seen that the nozzle plate 51, with its edge region 53, has penetrated into a nozzle channel wall 31 and is thereby fixed. Furthermore, it can be seen that the nozzle channel 30 has a tapered shape as a whole in the direction of the joining direction 2, with various conical sections being provided.

[0057] The filter 80 is positioned on the end face 20A and welded to the plastic carrier 20 in the area of ​​a circumferential weld 92. Due to the recess 24, the effective area of ​​the filter 80 is very large, in this case approximately twice the cross-section of the nozzle channel 30 at its narrowest point. The filter 80 can therefore filter comparatively large quantities of liquid without clogging.

[0058] The filter 80 can, for example, have a cutoff of 4 µm, thus filtering out all or almost all particles that cannot pass through the filter with pores of a corresponding size. The cutoff of 4 µm is well suited if the nozzle openings 52 have a clear cross-section of 8 µm. This adjustment ensures that all components of the liquid that can pass through the filter 80 can also be discharged through the nozzle openings.

[0059] As the Fig. 4A bis 4C As can be seen, the filter 80 can be designed in various ways. Fig. 4A bis 4C show variants of the Fig. 4 marked area A.

[0060] When designing according to Fig. 4A a depth filter is used, i.e. a filter 80 made of a porous and, for example, sintered material, which is penetrated by irregular pores, which result in particles of a certain size not being able to penetrate the depth filter but being trapped in it.

[0061] Fig. 4B shows a design with a membrane filter as filter 80. This filter has filter openings 82 that have a defined position and shape and can be introduced, for example, into the filter 80 or its filter material 180 by means of a laser beam. Particles larger than the cross-section of these filter openings cannot penetrate the filter 80 and collect on the upstream side of the filter 80.

[0062] In Fig. 4C A variant is shown in which a membrane filter is also used as filter 80. This has a filter membrane 80A similar to that of the Fig. 4B . In addition, a carrier layer 80B made of a coarse fleece is provided, which gives the filter membrane 80A the necessary stability.

[0063] The Fig. 4D shows area B of the Fig. 4 in which the nozzle plate 51 rests against the nozzle channel wall 31. It can be seen that the nozzle plate 51, penetrated by nozzle openings 52, has a tapered shape in the edge region 53 and that the outer contour 54 of the nozzle plate 51, due to the assembly method described below, leads to the creation of a compression zone 23 in the region of the nozzle channel wall 31, in which the plastic material of the plastic carrier 20 is compressed. Downstream and upstream of the nozzle plate 51, the nozzle channel wall 31 projects inward beyond the edge region 53 of the nozzle plate 51, so that the nozzle plate 51 is secured in a form-fitting manner.

[0064] The Fig. 5A bis 5G show the method for inserting the nozzle plate 51 into the plastic carrier 20.

[0065] As in Fig. 5A As shown, a nozzle plate 51 is first punched out from a carrier plate 150 having a plurality of nozzle plate regions 51' with nozzle openings 52 by means of a punching tool and its frontal punching surface 242, which in the present design alone forms the nozzle plate arrangement 50. This nozzle plate 51 is inserted into the plastic carrier 20 in the joining direction 2 from the input side 10A immediately after punching, i.e., without intermediate storage with other nozzle plates.

[0066] As in Fig. 5B As can be seen, the nozzle plate 51, due to a cross-section 40 on the inlet side which is larger than the outer contour 54 of the nozzle plate 51, directly penetrates quite deeply into the nozzle channel 30 and initially comes to rest in a conical section 36 of the nozzle channel wall 31.

[0067] As in Fig. 5C As is illustrated, an assembly tool 200 is then inserted from above in the joining direction 2 into the nozzle channel 30. With its outer contour 202, the assembly tool 200 also comes into contact with the nozzle channel wall 31 in the conical section 36. During the continued movement of the assembly tool 200 in the joining direction 2, this begins, as in Fig. 5D It can be seen that the nozzle channel 30 is elastically widened.

[0068] Due to this widening, the nozzle plate 51 also sinks downwards in the joining direction until it reaches its Fig. 5E The end position shown is reached. In the present example, this further movement of the nozzle plate 51 does not require direct contact with the assembly tool 200. In other embodiments of the method, however, it can also be provided that the assembly tool 200 is in contact with the nozzle plate 51 and can thus push it deeper into the nozzle channel 30.

[0069] Finally, in the Fig. 5F In a manner illustrated, the assembly tool 200 is pulled out of the nozzle channel 30 in the opposite direction to the joining direction 2. The nozzle plate 51 remains in the nozzle channel 30. The nozzle channel wall 31, which has been elastically expanded in the meantime, returns to its initial position, whereby it cannot completely reset in an annular region 22 in the area of ​​the end position of the nozzle plate 51 due to the nozzle plate 51, so that in a circumferential annular region 22 the already mentioned compression zone 23 remains, which in Fig. 4D is shown. However, on both sides of this compression zone 23 in the area of ​​the nozzle channel sections 32, 34, the nozzle channel wall 31 is reset. The nozzle channel wall 31 thereby returns to its original position to such an extent that the clear cross-sections 33, 35 there are smaller than the outer contour 54 of the nozzle plate 51.

[0070] The described assembly procedure ensures secure attachment of the nozzle plate 51 in the nozzle channel 30. Even external forces during assembly and pressure peaks during operation cannot loosen the nozzle plate 51. The remaining elastic compression in the compression zone 23 ensures that the nozzle plate 51 is securely held even during long storage periods.

[0071] The Fig. 6A bis 6C illustrate the application of the filter 80, wherein the method is preferably carried out with not yet completed nozzle units 10, which are produced according to the description of the Fig. 5A bis 5G were assembled.

[0072] Referring to Fig. 6A It can be seen that a filter material 180 is used, which can, for example, be unwound from a roll. This is placed over the plastic supports 20 already provided with the nozzle plate arrangement 50, so that, preferably in a continuous process, the plastic supports 20 can then be welded to the filter material 180 by means of a joining die 260 and a circumferential joining edge 262 provided thereon.

[0073] This results in a section of the filter material 180 to which a plurality of plastic supports 20 with nozzle plate arrangements 50 are thermally attached. Based on this, in the Fig. 6B In the manner illustrated, the filter material 180 is cut circumferentially around the end face 20A by means of a cutting tool 280. The nozzle units 10 thus completed, but not yet assembled, can be Fig. 6B can be handled without problems as indicated. Due to the already applied filter 80 and the interior of the nozzle units 10 being free of interfering particles due to the described manufacturing process, as well as due to the secure closure of the nozzle units 10 by the nozzle plates 51, there is no risk of contamination of the thus finished nozzle units 10 that would be disruptive during operation.

[0074] Fig. 6C shows again the finished nozzle units 10 with the filters 80 remaining after the cutting process, which are tightly sealed in the area of ​​the circumferential welding point 92 by the joining edge 262.

[0075] The Fig. 7 und 8 show an alternative design of the nozzle unit 10. The main difference compared to the nozzle unit 10 of the Fig. 4 is the design of the nozzle plate arrangement 50. In the present case, this consists not only of the nozzle plate 51, but additionally comprises a support frame 56 made of plastic, which is provided on the upstream side of the nozzle plate 51. The support frame 56 can, for example, be injection-molded onto the nozzle plate. It has a shape and, in particular, an outer contour 58, which allows the edge region 53 of the nozzle plate 51 to form a firm connection with the nozzle channel wall 31 in the manner described. The support frame 56 gives the nozzle plate arrangement 50 as a whole greater inherent stability and, moreover, reduces the risk of damage to the nozzle plate 51 by the assembly tool 200 during assembly.

[0076] Fig. 9 shows an alternative design in which a clamping element 90 in the form of a clamping ring 90 is provided, which in this case is provided instead of the weld point 92. Accordingly, the filter 80 is not connected to the plastic carrier 20 in a materially bonded manner, but is pressed axially against the end face 20A of the plastic carrier by the clamping ring 90 encompassing the rim section 28 in an edge-side clamping area 84.

[0077] Also in the design of the Fig. 10 The flat filter 80 is fixed by a clamping element 90 in the form of a clamping ring 90. Here, however, the clamping ring 90 is inserted into a recess in the plastic carrier 20 and radially clamps the material of the filter 80 in an edge-side clamping area 86 between its outer side and the edge of the recess in the plastic carrier 20.

[0078] The alternative design of the Fig. 11 shows the same basic principle with radial clamping of the filter 80 in the clamping area 86, wherein here the clamping ring 90 is arranged on the outside of the plastic carrier 20, so that it is an inner surface of the clamping ring 90 which in this case clamps the edge area of ​​the filter 80.

[0079] Fig. 12 shows an alternative design to that of the Fig. 4 , which differs from this in that the nozzle plate 51 adopts a curved configuration. Such a curved configuration can be advantageous due to the diverging orientation of the nozzle openings 52 and results in a more widely fanned spray jet.

[0080] To produce such a design, it is possible, on the one hand, to press the nozzle plates 51 plastically into a curved shape before they are introduced into the nozzle channel 30 and to carry out the process according to the Fig. 5A bis 5E otherwise be carried out unchanged.

[0081] How Fig. 13shows, it can alternatively also be provided that the assembly tool 200 has a convexly curved end face 204 and an auxiliary tool 220 is inserted into the nozzle channel 30 from the opposite side. This auxiliary tool 220 has a likewise curved, but this time concavely curved end face 224. During assembly, the assembly tool 200 and the auxiliary tool 220 together elastically press the originally flat nozzle plate 51 into a curved shape and bring it into its final position in this elastically deformed state. When the assembly tool and the auxiliary tool 220 are then pulled out of the nozzle channel 30 in opposite directions, this curved shape is at least partially retained.

Claims

1. Method for producing a nozzle unit (10) for a liquid dispenser (100), having the following features: a. the method is used to produce a nozzle unit (10) with a plastic carrier (20), which is traversed by a nozzle channel (30) from an inlet side (10A) to an outlet side (10B), and with a nozzle plate arrangement (50), which has a multiplicity of nozzle openings (52) and is inserted into this nozzle channel (30), and b. the method is carried out using an assembly tool (200), c. the assembly tool (200) has an outer contour (202) with an oversize in relation to the nozzle channel (30), such that the assembly tool (200), by being inserted into the nozzle channel (30) and by applying force there to a nozzle channel wall (31), can elastically expand the nozzle channel (30), and d. the assembly tool (200) has an end face (204) which is larger than an outer contour (54) of the nozzle plate arrangement (50), and e. the method comprises the following method steps: - the plastic carrier (20) is brought into a defined assembly position, and - the nozzle plate arrangement (50) and then the assembly tool (200) are inserted in a joining direction (2) into the nozzle channel (30) from the inlet side (10A), and - with progressive insertion of the assembly tool (200) into the nozzle channel (30) in the joining direction (2), the nozzle channel (30) is partially expanded elastically by the assembly tool (200), such that the nozzle plate arrangement (50) is brought to an elastically expanded end position, and - the assembly tool (200) is withdrawn from the nozzle channel (30) counter to the joining direction (2), wherein the nozzle plate arrangement (50) remains in the end position and, after complete removal of the assembly tool (200), is held by the nozzle channel wall (31) as a result of the elastic resetting of the nozzle channel (30).

2. Method according to Claim 1, having the following further features: a. the nozzle plate arrangement (50) is designed as a one-piece nozzle plate (51) which, by means of a punching process, is punched out from a carrier plate (150) with a plurality of nozzle plate regions (51'), and b. after the nozzle plate (51) has been punched out, the nozzle plate (51) is directly inserted into the nozzle channel (30) in a joining direction (2) from the inlet side (10A).

3. Method according to Claim 1 or 2, having the following further features: a. the nozzle channel (30) has at least one conical sub-portion (36) which, at its end pointing in the direction of the inlet side (10A), has a cross section (40) which is larger than the outer contour (202) of the assembly tool (200), and, at its end pointing in the direction of the outlet side (10B), has a cross section which is smaller than the outer contour (202) of the assembly tool (200), and b. during the insertion of the assembly tool (200) into the nozzle channel (30), the assembly tool (200) comes into contact with the nozzle channel wall (31) of the nozzle channel (30) in the conical sub-portion (36).

4. Method according to one of the preceding claims, having the following further feature: a. as the assembly tool (200) is progressively inserted into the nozzle channel (30) in the joining direction (2), an auxiliary tool (220) is pushed, in alignment with the assembly tool (200), into the nozzle channel (30) from the outlet side (10B).

5. Method according to one of the preceding claims, having the following further features: a. the end face (204) of the assembly tool (200) has a convexly curved shape and / or an end face (224) of the auxiliary tool (220) has a concavely curved end face, and b. during the insertion of the assembly tool (200) into the nozzle channel (30), the concave shape and / or the convex shape presses the nozzle plate arrangement elastically and / or plastically into a curved shape.

6. Method according to one of the preceding claims, having at least one of the following further features: a. the plastic carrier (20) is oriented, in the defined assembly position, in such a way that the inlet side (10A) points upwards and the outlet side (10B) points downwards, and / or b. after removal of the assembly tool (200), the nozzle plate arrangement (50) is heated, at least in parts, to at least up to 100°C.