Dosing valve with cleaning device

Abstract

A dosing valve for dispensing a fluid, the dosing valve comprising an inlet (4) and an outlet (6) for the circulation of pressurised fluid (8) to be metered, a nozzle (10) for dispensing the fluid (8), wherein the nozzle (10) has at least one outlet opening (16, 18, 19), which can be closed by means of at least one valve piston (12, 14, 15) of the dosing valve (2, 76), and a nozzle head (20) of the nozzle (10) for steel moulding of the fluid (8), wherein the dosing valve (2, 76) has a cleaning device (22) for cleaning the nozzle (10).

Description

[0001] The present invention relates to a dosing valve. The invention also relates to a dosing device for mixing fluids and a method for using a dosing valve or a device for dosing fluids.

[0002] Paints or varnishes are usually stored and transported in sealed storage containers. Filling into these containers is fully automated, whereby the filling process simultaneously involves mixing different components so that different fluids are dosed into one container in order to fill the desired product as a finished mixture.

[0003] During dosing and simultaneous mixing, the individual components of the paints or varnishes are dosed from storage tanks into the containers using dosing valves. The paints or varnishes are thus a mixture of different fluids, whereby the individual fluids are each dosed via specially assigned dosing valves and thus mixed in the container. A dosing device for dosing or mixing fluids in containers provided for this purpose is known, for example, from the publications EP 3 142 783 B1 and EP 0 786 287 A1, which go back to the applicant.

[0004] Valves for dispensing fluids tend to clog over time. This is a particular problem when fluids such as paints or varnishes that contain volatile substances for rapid drying need to be dispensed. To prevent such a dispensing valve from clogging, it is advantageous to clean or rinse the nozzle head of such a dispensing valve regularly. The terms "cleaning" and "rinsing" as well as "rinsing device" and "cleaning device" are used synonymously in this text.

[0005] A nozzle head can be rinsed manually by wiping or washing out the nozzle head with a cleaning fluid. Rinsing can also be carried out using a rinsing device that is moved towards the nozzle head to be rinsed in order to rinse the nozzle head when not in use. A rinsing fluid can be sprayed into the nozzle head from the outside as a cleaning jet.

[0006] The aforementioned procedures for cleaning a nozzle head have the disadvantage that they are ineffective, as the inside of the nozzle head is difficult to access. Furthermore, cleaning the nozzle head with a cleaning device requires a large amount of cleaning fluid to flush out the nozzle head. The cleaning fluid must be collected and disposed of.

[0007] Against this background, the present invention is based on the technical problem of specifying an improved dosing valve which enables efficient and reliable operation and, in particular, can be cleaned more efficiently. Furthermore, a dosing device with such a dosing valve and a method for dosing fluid are to be disclosed.

[0008] The above technical problem is solved in each case with the features of the independent claims. Further embodiments of the invention result from the dependent claims and the following description.

[0009] According to a first aspect, the invention relates to a dosing valve for dispensing a fluid, wherein the dosing valve comprises: an inlet and an outlet for circulating pressurised fluid to be metered, a nozzle for dispensing the fluid, wherein the nozzle has at least one outlet opening which can be closed by means of at least one valve piston of the dosing valve, and a nozzle head of the nozzle for beam shaping the fluid. The dosing valve is characterised in that the dosing valve has a cleaning device for cleaning the nozzle.

[0010] The fact that the cleaning device is an integral part of the dosing valve in particular means that the nozzle can be flushed and cleaned in a more targeted manner, which enables improved cleaning with a smaller amount of cleaning fluid compared to external, separate cleaning devices.

[0011] The amount of cleaning fluid used to clean the nozzle can, in particular, be so small that the cleaning fluid is discharged into the filling container into which the fluid to be dosed is filled. The quantity of cleaning fluid is therefore so small that the quality of the fluid to be dosed is not impaired. It can be provided, that the cleaning fluid is discharged into the filling container, if the filling container has a volume of at least 60 liters. If the filling container has a volume of less than 60, cleaning fluid is discharged on a drip plate or another waste container, outside the filling container.

[0012] The cleaning process is therefore more efficient overall, as no cleaning fluid has to be collected and disposed of as a waste product, cleaning of the nozzle is improved and a smaller amount of cleaning fluid is required overall.

[0013] The cleaning process is also less time-consuming, as no external cleaning device needs to be transported to the dosing valve to be cleaned. This means that the cleaning process can be carried out at any time during operation.

[0014] The cleaning device has an inlet for supplying pressurised cleaning fluid. During operation, the dosing valve is therefore coupled on the one hand to a storage tank in which the fluid to be dosed is stored and on the other hand to another storage tank for storing the cleaning fluid.

[0015] The inlet for supplying cleaning fluid is provided separately from the inlet for supplying fluid to be dosed to the dosing valve. The dosing valve is therefore not flushed via the inlet for supplying fluid to be dosed, but via a separate inlet that is different from it.

[0016] The cleaning device has a valve for controlling a cleaning process. The valve is in particular a pneumatic valve. It is understood that, according to alternative embodiments of the invention, other types of valves can also be used for switching and purging pressurised fluid, such as solenoid valves, hydraulic valves, mechanical valves, electromechanical valves or the like.

[0017] In particular, the cleaning device can be controlled independently and separately from the valve piston of the dosing valve. The cleaning process can therefore take place independently of the position of the valve piston. The cleaning process can theoretically take place at any time, i.e. before and / or during and / or after the dosing process.

[0018] The nozzle head can have at least one fluid channel, wherein the fluid channel penetrates in particular a wall of the nozzle head from an outer side of the nozzle head to an inner side of the nozzle head, and wherein the fluid channel is connected to the cleaning device for the supply of pressurised cleaning fluid.

[0019] The fluid channel can have a diameter selected from a range of 0,5 mm to 2,0 mm, in particular selected from a range of 0,8 mm to 1,5 mm, or in particular can be approximately 1 mm.

[0020] The nozzle head is used for jet shaping of the fluids to be dosed and, in particular, simultaneously forms a spray head of the cleaning device for dispensing the cleaning fluid. For this purpose, the nozzle head can have a fluid channel or several fluid channels, the mouth of which forms a spray opening or the mouths of which form spray openings for spraying out the cleaning fluid.

[0021] The fluid channel can have an inclination relative to a longitudinal axis of the valve piston of the dosing valve and the fluid channel can be set up in particular for discharging fluid in the direction of the outlet opening of the nozzle. In the event that several fluid channels are provided, each fluid channel can have an inclination relative to the longitudinal axis of the valve piston of the dosing valve. All the fluid channels can have the same inclination relative to the longitudinal axis of the valve piston of the dosing valve.

[0022] The fluid channels can have different inclinations relative to the longitudinal axis of the valve piston of the dosing valve.

[0023] The inclination relative to the longitudinal axis of the valve piston can be selected from a range of 45° to 75°, in particular from a range of 55° to 65°, or can in particular be approx. 60°.

[0024] A circumferential supply channel can be formed in the area of the outside of the nozzle head, whereby the circumferential supply channel is connected to the cleaning device and whereby the fluid channel opens into the circumferential supply channel. If several fluid channels are provided, each respective fluid channel in particular opens into the circumferential supply channel.

[0025] Two or more fluid channels can be provided, in particular four or more fluid channels can be provided, in particular exactly four fluid channels can be provided. In particular, the fluid channels can be arranged at equidistant angular distances from one another. The angular spacings relate to the longitudinal axis of the valve piston. In other words, the fluid channels and / or their outlet openings provided for discharging the cleaning fluid can be evenly distributed in order to achieve a cleaning or rinsing result that is as homogeneous as possible.

[0026] The cleaning device can have a connecting section, whereby the connecting section surrounds the nozzle head on the circumference. The connecting section can be screwed to the nozzle head or otherwise detachably attached to the nozzle head. The connecting section can be hooked onto the nozzle head and held positively on the nozzle head. The connecting section can rest on a collar of the nozzle head. The connecting section can be accommodated between a shoulder of the nozzle head and a shoulder of a housing of the dosing valve and held in a form-fitting manner.

[0027] The nozzle head can penetrate an opening in the connecting section, so that the nozzle head sits at least partially within the connecting section.

[0028] The nozzle head is protruding in an axial longitudinal direction over the connecting section and / or protruding over the cleaning device. The cleaning device is therefore integrated into the dosing valve in such a way that the axial accessibility of the nozzle head does not deteriorate in comparison to previously known solutions without an integrated cleaning device. The cleaning device therefore does not form a collision structure and does not lead to shading between the outlet opening and a container, so that the fluid flow is not impaired by the cleaning device.

[0029] The circumferential supply channel can be formed between the connecting section and the nozzle head and can be limited by the connecting section and the nozzle head, wherein the circumferential supply channel has in particular a circumferential groove and wherein the circumferential groove is formed in particular on the connecting section and / or the nozzle head. In this way, a cost-effective integration of the supply channel can be achieved.

[0030] The nozzle head can have two sleeves, namely an inner sleeve and an outer sleeve, whereby the inner sleeve sits partially or completely in an opening of the outer sleeve.

[0031] The fluid channel or fluid channels can be formed between the inner and outer sleeve. In particular, the inner sleeve and / or the outer sleeve can have grooves that delimit a respective fluid channel. The inner sleeve and / or the outer sleeve may alternatively or additionally have a through opening or several through openings in order to form a respective fluid channel.

[0032] The nozzle head can have an inner jacket surface which has a non-constant diameter at least in sections, wherein the inner jacket surface is widened from a first diameter to a second diameter when viewed along an outflow direction of the fluid, the inner jacket surface is narrowed from the second diameter to a third diameter. The second diameter is larger than the first diameter and the second diameter is larger than the third diameter.

[0033] Investigations by the applicant have shown that the widening and then narrowing shape results in a jet shape of the fluid to be dosed that is favourable for dosing fluids. In this case, we can speak of an at least partially convex, i.e. outwardly curved inner surface.

[0034] The first diameter and the third diameter can be the same size. The first diameter and the third diameter can be different sizes.

[0035] The inner jacket surface, which widens and narrows again, is arranged downstream of the outlet opening and is intended for jet shaping.

[0036] The fluid channel or fluid channels of the nozzle head are arranged downstream of the outlet opening and are intended for cleaning.

[0037] The widening area and the narrowing area of the inner jacket surface can merge into one another without any jumps, whereby in particular a transition radius can be formed between the widening area and the narrowing area of the inner jacket surface.

[0038] Adjacent to the narrowing area of the jacket surface, one or more steps can be arranged, which can be circular cylindrical steps, for example. The steps can be widening.

[0039] It may be provided that a first step or shoulder is provided which has a fourth diameter that is larger than the third diameter.

[0040] It may be provided that a second step or shoulder is provided which has a fifth diameter which is larger than the third diameter and which is larger than the fourth diameter.

[0041] It is possible that the fifth diameter is larger than the second diameter.

[0042] It may be provided that no further step or shoulder is arranged adjacent to the narrowing area of the lateral surface, but that the third diameter forms the edge or the plane along which the fluid to be dosed leaves the nozzle head in the axial direction or emerges from an interior of the nozzle head.

[0043] An opening of the fluid channel into an interior of the nozzle head can be arranged on the inner jacket surface in the area of the inner jacket surface, which widens from the first diameter to the second diameter, or adjacent to it. In this way, at least partial shading of the mouth of the fluid channel to the outlet opening can be achieved. Clogging of the mouth of the fluid channel with paint or varnish can be avoided.

[0044] The nozzle head can have a sleeve insert that is arranged downstream of the outlet opening and is intended for jet or beam shaping of the pressurised fluid to be dosed. The sleeve insert can be the inner sleeve described above.

[0045] The inner jacket surface of the nozzle head can correspond at least in sections to the inner jacket surface of the sleeve insert or be formed by the inner jacket surface of the sleeve insert.

[0046] The metering valve may be provided with two valve pistons and two outlet openings, namely a first valve piston for opening and closing a first outlet opening of the nozzle, a first spring being provided to keep the first valve piston pre-tensioned in a closed position, a second valve piston for opening and closing a second outlet opening of the nozzle, a second spring being provided to keep the second valve piston pre-tensioned in a closed position, the first valve piston and the second valve piston being arranged coaxially wherein the first valve piston is movable from the closed position to a first open position without lifting the second valve piston from its closed position, thereby providing a first open condition of the dosing valve, wherein the first valve piston is movable from the first open position to a second open position engaging the second valve piston and lifting the second valve piston from its closed position, thereby providing a second open condition of the dosing valve.

[0047] The dosing valve can therefore be a multi-stage dosing valve, which enables step-by-step control of the dispensed volume flow. If intermediate positions of the individual valve pistons can be approached, infinitely variable control of the dispensed volume flow is also possible.

[0048] Furthermore, it may be provided that the first piston has a projecting element for positively lifting the second piston from the second outlet opening and wherein the projecting element of the first piston is arranged in an opening of the second piston in order to provide an idle stroke of the first piston relative to the second piston, wherein the projecting element is arranged at a distance from a stop surface of the second piston during the idle stroke when moving the first piston from the closed position into the first open position of the first piston.

[0049] It may be provided that the dosing valve additionally comprises a third valve piston for opening and closing a third outlet of the nozzle, wherein a third spring is provided for pre-tensioning the third valve piston in a closed position, wherein the first piston, the second piston and the third piston are arranged coaxially, wherein the first piston is movable from the closed position to the first open position and to the second open position, without lifting the third piston from its closed position, thereby providing the first open condition of the dispensing valve, the first piston being movable from the second open position to a third open position which engages the third piston and lifts the second and third pistons from their closed positions, thereby providing a third open condition of the dispensing valve.

[0050] According to a further aspect, the invention relates to a dosing device for mixing fluids, wherein the dosing device comprises: a frame and at least one dosing valve, wherein the dosing valve is designed according to the invention and wherein the dosing valve is attached to the frame.

[0051] The dosing valve can be held movably on the frame, whereby the dosing valve can be moved from a waiting position at a distance from the dosing point to a dosing position above a container.

[0052] A plurality of dosing valves according to the invention can be held on the frame, in particular held on the frame in a movable manner as described above.

[0053] The dosing valves can be arranged in a circle or partial circle around the dosing point, whereby each of the dosing valves can be displaced in a radial direction to the dosing position.

[0054] According to a further aspect, the invention relates to a method comprising the method steps of: using a dosing device according to the invention or a dosing valve according to the invention to fill a container with at least one fluid, wherein the fluid is dosed into the container by means of the dosing valve; cleaning the nozzle of the dosing valve, wherein the cleaning takes place before and / or after the dosing of the fluid.

[0055] A cleaning fluid used to clean the nozzle of the dosing valve is discharged into the same container into which the fluid is also dosed by means of the dosing valve. The quantity of cleaning fluid used to clean the nozzle is so small that the quality of the fluid to be dosed is not impaired. The contamination caused by the rinsing fluid is therefore below the limit of tolerance with regard to the contamination of the fluid to be dosed.

[0056] When we talk about fluids in this text, we are referring in particular to liquids, i.e. substances that are liquid at room temperature, such as paints and varnishes.

[0057] The invention is described in more detail below with reference to embodiments illustrated in the drawings. The drawings show schematically in each case: Fig. 1a cross-section of a first dosing valve according to the invention; Fig. 2a sectional enlargement of the dosing valve from Fig. 1; Fig. 3a cross-section of the nozzle head of the dosing valve from Fig. 1; Fig. 4a perspective view of the nozzle head from Fig. 3; Fig. 5a cross-section of a second dosing valve according to the invention; Fig. 6a front view of a dosing device for mixing fluids according to the invention; Fig. 7the dosing device from Fig. 6 in a plan view; Fig. 8process steps of a process according to the invention.

[0058] Fig. 1 shows a cross-section of a first dosing valve 2 according to the invention.

[0059] The dosing valve 2 is set up to dose a fluid 8. The dosing of the fluid 8 can also be referred to as dispensing or metering of the fluid 8.

[0060] The dosing valve has an inlet 4 and an outlet 6 for the circulation of pressurised fluid 8 to be dosed.

[0061] The dosing valve 2 has a nozzle 10 for dispensing the fluid 8.

[0062] The dosing valve 2 is a three-stage valve and has three valve pistons 12, 14, 15 and three outlet openings 16, 18, 19 - namely a first valve piston 12 for opening and closing a first outlet opening 16 of the nozzle 10, a second valve piston 14 for opening and closing a second outlet opening 18 of the nozzle 10 and a third valve piston 15 for opening and closing a third outlet opening 19 of the nozzle 10.

[0063] As part of the nozzle 10, the dosing valve 2 has a nozzle head 20 for shaping the flow or beam of the pressurised fluid 8 to be dispensed.

[0064] The dosing valve 2 has a cleaning device 22 for cleaning the nozzle 10.

[0065] The cleaning device 22 has an inlet 24 for supplying pressurised cleaning fluid 26.

[0066] The cleaning device 22 has a valve 28 for controlling a cleaning process. The valve 28 is a pneumatic valve. The pneumatic valve 28 has pneumatic connections 30, 32 for controlling or switching the valve 28.

[0067] Fig. 2 shows a sectional enlargement of the dosing valve 2. To improve clarity, the fluid 8 to be dosed and the designations of the outlet openings 16, 18, 19 are not shown in the area of the nozzle head 20.

[0068] The nozzle head 20 has fluid channels 34. The respective fluid channels 24 penetrate a wall 36 of the nozzle head 20 from an outer side 38 of the nozzle head 20 to an inner side 40 of the nozzle head 20.

[0069] The fluid channels 34 are connected to the cleaning device 22 for the supply of pressurised cleaning fluid 26. As can be seen in Fig. 2, the pressurised cleaning fluid 26 can be sprayed via the fluid channels 34 in the direction of the valve pistons 12, 14, 15 closing the outlet openings 16, 18, 19 in order to flush or clean the nozzle 20.

[0070] The fluid channels 34 have an inclination relative to a longitudinal axis L of the valve pistons 12, 14, 15 of the dosing valve 2. Due to the respective inclination, the fluid channels 34 are each set up for the discharge of cleaning fluid 26 in the direction of the outlet openings 16, 18, 19 of the nozzle 10.

[0071] The fluid channels 34 are arranged at equidistant angular distances from one another around the longitudinal axis L. In other words, the present four fluid channels 34 have a respective angular spacing of 90° from one another, i.e. from the respective neighbouring fluid channels 34, when viewed from above along the longitudinal axis L.

[0072] The design of the nozzle head 20 is described in more detail below with reference to Fig. 3, which shows the nozzle head 20 individually in cross-section.

[0073] The nozzle head 20 is composed of two sleeves, namely an inner sleeve 42 and an outer sleeve 44. The inner sleeve 42 can also be referred to as a sleeve insert, since the inner sleeve 42 is seated in the outer sleeve 44 of the nozzle head 20.

[0074] The inner sleeve 42 or the sleeve insert 42 is arranged downstream of the outlet openings 16, 18, 19 in the fully assembled state and is intended for jet shaping of the pressurised fluid 8 to be dispensed (Fig. 1).

[0075] In the present case, the inner sleeve 42 sits completely in an opening 46 of the outer sleeve 44 (Fig. 3).

[0076] The fluid channels 34 are formed between the inner sleeve 42 and the outer sleeve 44. The inner sleeve 42 has grooves 48 which delimit a respective fluid channel 34. The fluid channels 34 therefore consist, at least in sections, of grooves 48 of the inner sleeve 42.

[0077] The outer sleeve 44 also has a plurality of through openings 50 to form the fluid channels 34. The through openings 50 merge into the grooves 48 to form the fluid channels 34.

[0078] An angle of inclination a of the fluid channels 34 relative to the longitudinal axis L is approximately 60° in the present case.

[0079] Part of a circumferential supply channel 52 is formed in the area of the outer side 38 of the nozzle head 20.

[0080] The circumferential supply channel 52 is connected to the cleaning device 22 when the nozzle head 20 is fully assembled.

[0081] All fluid ducts 34 open into the circumferential supply duct 52, so that all fluid ducts 34 can be supplied with cleaning fluid 26 by means of the supply duct 52.

[0082] The circumferential supply channel 52 is limited by a circular groove 54 of the outer sleeve 44 of the nozzle head 20.

[0083] Furthermore, the circumferential supply channel 52 is delimited by a connecting section 56 of the cleaning device 22, which surrounds the outer sleeve 44 on the circumferential side at the level of the circular circumferential groove 54 (Fig. 2).

[0084] The connecting section 56 is received between a collar 58 of the outer sleeve 44 of the nozzle head 20 and a shoulder 60 of a housing 62 of the dosing valve 2 and is held in a form-fitting manner.

[0085] The nozzle head 20 is protruding in an axial longitudinal direction along the longitudinal axis L at least in sections over the connecting section 56 and protruding overall over the cleaning device 22.

[0086] The nozzle head 20 has an inner jacket surface 64, which has a non-constant diameter, at least in sections.

[0087] The inner jacket surface 64 is widened from a first diameter d1 to a second diameter d2 when viewed along an outflow direction R of the fluid to be dispensed. The inner jacket surface 64 is narrowed from the second diameter d2 to a third diameter d3 when viewed along the outflow direction R of the fluid to be dosed. The second diameter d2 is larger than the first diameter d1 and the second diameter d2 is larger than the third diameter d3.

[0088] A respective mouth 66 of a respective fluid channel 34 into an interior 67 of the nozzle head 20 is arranged on the inner jacket surface 64 and in the respective region of said inner jacket surface 64, which widens from the first diameter d1 to the second diameter d2.

[0089] With reference to Figures 1 and 2, the design of the dosing valve 2 is described in more detail below.

[0090] As already mentioned at the beginning, the dosing valve 2 is a three-stage dosing valve. The three valve pistons 12, 14, 15 can be lifted sequentially from the three outlet openings 16, 18, 19 in order to dispense the fluid 8 to be dosed via the outlet openings 16, 18, 19. The dosing valve 2 is operated via a pull rod 68.

[0091] A first spring 70 is associated with the first valve piston 12, which holds the first valve piston 12 preloaded in a closed position and presses it into the first outlet opening 16.

[0092] A second spring 72 is associated with the second valve piston 14, which holds the second valve piston 14 pretensioned in a closed position and presses it into the second outlet opening 18.

[0093] A third spring 74 is associated with the third valve piston 15, which holds the third valve piston 14 pretensioned in a closed position and presses it into the third outlet opening 18.

[0094] The valve pistons 12, 14, 15 are arranged coaxially to each other. The outlet openings 16, 18, 19 are arranged coaxially to each other.

[0095] The first valve piston 12 sits inside the second valve piston 14, with the second valve piston 14 having the first outlet opening 16 at the end.

[0096] The second valve piston 14 sits inside the third valve piston 15, with the third valve piston 15 having the second outlet opening 18 at the end.

[0097] The third valve piston 15 is located inside the nozzle head 20, with the nozzle head 20 forming the third outlet opening 19 with its inner jacket surface 64.

[0098] The first valve piston 12 can be moved from the closed position to a first open position without lifting the second valve piston 14 from its closed position, thereby providing a first opening state of the dosing valve 2.

[0099] The first valve piston 12 is movable from the first open position to a second open position, wherein the first valve piston 12 engages with the second valve piston 14 and lifts the second valve piston 14 from its closed position, thereby providing a second opening state of the dosing valve 2.

[0100] The first valve piston 12 can be moved from the closed position to the first and second open positions without lifting the third piston 15 from its closed position in order to provide the first opening state of the dispensing valve.

[0101] The first valve piston 12 has a projecting element 75 for positive lifting of the second piston 14 from the second outlet opening 18.

[0102] The projecting element 75 of the first valve piston 14 is arranged in an opening of the second valve piston 14 in order to initially provide an idle stroke of the first valve piston 12 relative to the second valve piston 14 for the movement of the first valve piston 12 from the closed position to its first open position.

[0103] During the idle stroke when the first valve piston 12 is moved from the closed position into the first open position of the first valve piston 12, the projecting element 75 is arranged at a distance from a stop surface of the second valve piston 14.

[0104] When the first open position of the first valve piston 12 is reached, the projecting element 75 is brought into contact with the stop surface of the second valve piston 14, so that the second valve piston is carried along by the positive fit when the first valve piston 12 is lifted further.

[0105] The same principle is used to lift the third valve piston. The first valve piston thus performs an idle stroke relative to the third valve piston 15 from the closed position to the second open position, so that the latter remains in its closed position.

[0106] When the second position is reached, the projecting element 75, which can also be referred to as a driver, comes into contact with a stop surface of the third valve piston 15, so that further lifting of the first valve piston 12 leads to positive lifting of the third valve piston 15. The principle is obvious from Fig. 5.

[0107] In this way, a third opening state of the dosing valve 2 can be provided. It is understood that intermediate positions can be set for each valve piston so that continuous flow rate adjustments are possible between the aforementioned positions.

[0108] Fig. 5 shows a second dosing valve 76 according to the invention in cross-section. To avoid repetition, only the differences to the embodiment example described above are discussed below, with the same reference signs being assigned to the same features.

[0109] The second dosing valve 76 differs from the first dosing valve 2 in that the second dosing valve 76 is a two-stage dosing valve.

[0110] The second dosing valve has only two pistons 12, 15 with the respective outlet openings 16, 19.

[0111] The second dosing valve 76 further differs from the first dosing valve 2 in that the second Dosing valve 76 has a nozzle head 78, which is shaped like a step at the end.

[0112] Thus, an inner jacket surface 80 of the nozzle head 78 has two circular cylindrical steps 84, 86 adjacent to a narrowing region 82 of the jacket surface 80, which form a step-like widening of the cross-section.

[0113] Fig. 6 shows a dosing device 90 according to the invention for mixing fluids, wherein the dosing device 90 has a frame 92 and a plurality of dosing valves 2 and / or a plurality of dosing valves 76, which are configured in accordance with the invention.

[0114] The dosing valves 2, 76 are held on the frame 92. The dosing valves 2, 76 are movably held on the frame 92 and can be positioned from the shown waiting position into a dosing position above a container 94 in order to dose fluid 8 into the container 94.

[0115] Each of the dispensing valves 2, 76 may be provided for dispensing a respective liquid that is different from the liquids dispensed by the other dispensing valves 2, 76. Thus, different liquids can be sequentially dispensed into the container 94 to provide a product, such as a paint or varnish, as a mixture of different liquids.

[0116] In particular, a respective dosing valve 2, 72 can be cleaned with its respective cleaning device 22 before and / or after dosing.

[0117] Cleaning can take place in the dosing position so that the rinsing fluid 28 is discharged into the container 94.

[0118] According to the invention, a method can therefore be specified, comprising the method steps:

[0119] (A) Using the dosing device 90 to fill the container 94 with at least one fluid 8, wherein the fluid 8 is dosed into the container 94 by means of the dosing valve 2, 76; (B) cleaning the nozzle 10 of the dosing valve 2, 76, wherein the cleaning takes place before and / or after the dosing of the fluid 8.

[0120] The cleaning fluid 26 used to flush the nozzle 10 of the dosing valve is discharged into the same container 94 into which the fluid 8 is also dosed by means of the dosing valve 2, 76.REFERENCE SIGNS

[0121] 2Dosing valve 4Admission 6Outlet 8Fluid / fluid to be dosed 10Nozzle 12Valve piston 14Valve piston 15Valve piston 16Outlet opening 18Outlet opening 19Outlet opening 20Nozzle head 22Cleaning device 24Admission 26Rinsing fluid 28Valve 30Pneumatic connection 32Pneumatic connection 34Fluid channels 36Wall 38Outside 40Inside 42Inner sleeve 44Outer sleeve 46Opening 48Groove 50Passage opening 52Supply channel 54Groove 56Connecting section 58Collar 60Paragraph 62Housing 64Inner jacket surface 66Mouth 67Interior 68Tie rod 70Spring 72Spring 74Spring 75projecting element 76Dosing valve 78Nozzle head 80Inner jacket surface 82Narrowing area of the lateral surface 84Paragraph 86Paragraph 90Dosing device 92Frame 94Container (A)Process step (B)Process step d1diameter d2Diameter d3Diameter LLongitudinal axis RDirection

Claims

1. Dosing valve for dispensing a fluid, the dosing valve comprising: an inlet (4) and an outlet (6) for the circulation of pressurised fluid (8) to be dosed, a nozzle (10) for dispensing the fluid (8), wherein the nozzle (10) has at least one outlet opening (16, 18, 19) which can be closed by means of at least one valve piston (12, 14, 15) of the dosing valve (2, 76), and a nozzle head (20) of the nozzle (10) for beam shaping of the fluid (8), characterised in that the dosing valve (2, 76) has a cleaning device (22) for cleaning the nozzle (10).

2. Dosing valve according to claim 1, characterised in that the cleaning device (22) has an inlet for supplying pressurised cleaning fluid (26).

3. Dosing valve according to one of the preceding claims, characterised in that the cleaning device (22) has a valve (28) for controlling a cleaning process, wherein the valve (28) is in particular a pneumatic valve.

4. Dosing valve according to one of the preceding claims, characterised in that the nozzle head (20) has at least one fluid channel (34), wherein the fluid channel (34) penetrates in particular a wall (36) of the nozzle head (20) from an outer side (38) of the nozzle head (20) to an inner side (40) of the nozzle head (20), and wherein the fluid channel (34) for supplying pressurised cleaning fluid (26) is connected to the cleaning device (22).

5. Dosing valve according to claim 4, characterised in that the fluid channel (34) has an inclination relative to a longitudinal axis (L) of the valve piston (12, 14, 15) of the dosing valve (2, 76) and the fluid channel (34) is arranged in particular for discharging cleaning fluid (26) in the direction of at least one outlet opening (16, 18, 19) of the nozzle (10).

6. Dosing valve according to one of claims 4 or 5, characterised in that a circumferential supply channel (52) is formed in the region of the outside (38) of the nozzle head (20), wherein the circumferential supply channel (52) is connected to the cleaning device (22) and wherein the fluid channel (34) opens into the circumferential supply channel (52).

7. Dosing valve according to any one of claims 4 to 6, characterised in that two or more fluid channels (34) are provided, the fluid channels (34) being arranged in particular at equidistant angular distances from one another.

8. Dosing valve according to one of the preceding claims, the cleaning device (22) has a connecting section (56), wherein the connecting section (56) surrounds the nozzle head (20) on the periphery.

9. Dosing valve according to claim 8, characterised in that the nozzle head (20) is protruding in an axial longitudinal direction over the connecting section (56) and / or is protruding over the cleaning device (22).

10. Dosing valve according to claim 8 or 9 and according to one of claims 4-6, characterised in that the circumferential supply channel (52) is formed between the connecting section (56) and the nozzle head (20) and is delimited by the connecting section (56) and the nozzle head (20), wherein the circumferential supply channel (52) has in particular a circumferential groove (54) and wherein the circumferential groove (54) is formed in particular on the connecting section (56) and / or the nozzle head (20).

11. Dosing valve according to one of the preceding claims, characterised in that the nozzle head (20) has an inner jacket surface (40) which has a non-constant diameter at least in sections, wherein the inner jacket surface (40) is widened from a first diameter (d1) to a second diameter (d2) when viewed along an outflow direction (R) of the fluid (8), the inner jacket surface (40) is narrowed from the second diameter (d2) to a third diameter (d3), and the second diameter (d2) is larger than the first diameter (d1) and the second diameter (d2) is larger than the third diameter (d3).

12. Dosing valve according to one of the preceding claims 4-7 and according to claim 11, characterised in that an orifice (66) of the fluid channel (34) into an interior (68) of the nozzle head (20) is arranged on the inner jacket surface (40) in the region of the inner jacket surface (64), which widens from the first diameter to the second diameter, or adjacent thereto.

13. Dosing valve according to one of the preceding claims, characterised in that the nozzle head (20) has a sleeve insert (42) which is arranged downstream of the outlet opening (16, 18, 19) and is provided for jet shaping of the fluid (8) to be dosed.

14. Dosing valve according to one of the preceding claims, characterised in that the dosing valve (2, 76) has two valve pistons (12, 14) and two outlet openings (16, 18), namely a first valve piston (12) for opening and closing a first outlet opening (16) of the nozzle (10), wherein a first spring (70) is provided to keep the first valve piston (12) pretensioned in a closed position, a second valve piston (14) for opening and closing a second outlet opening (18) of the nozzle (10), wherein a second spring (72) is provided to keep the second valve piston (14) pre-tensioned in a closed position, wherein the first valve piston (12) and the second valve piston (14) are arranged coaxially, wherein the first valve piston (12) is movable from the closed position to a first open position without lifting the second valve piston (14) from its closed position, thereby providing a first opening condition of the dosing valve (2, 76), wherein the first valve piston (12) is movable from the first open position to a second open position, wherein the first valve piston (12) engages the second valve piston (14) and lifts the second valve piston (14) from its closed position, thereby providing a second opening condition of the dosing valve (2, 76).

15. Dosing valve according to claim 14, characterised in that the first valve piston (12) has a projecting element (75) for positively lifting the second valve piston (14) from the second outlet opening (18), and wherein the projecting element (75) of the first piston (12) is arranged in an opening of the second valve piston (14) to provide an idle stroke of the first valve piston (12) relative to the second valve piston (14), wherein the projecting element (75) is arranged at a distance from a stop surface of the second valve piston (14) during the idle stroke when the first valve piston (12) is moved from the closed position into the first open position of the first valve piston (12).

16. Dosing valve according to claim 14 or claim 15, characterised in that the dosing valve (2) additionally comprises: a third valve piston (15) for opening and closing a third outlet opening (19) of the nozzle (10), wherein a third spring (74) is provided to hold the third valve piston (15) pre-tensioned a closed position, wherein the first valve piston (12), the second valve piston (14) and the third valve piston (15) are arranged coaxially, wherein the first valve piston (12) is movable from the closed position into the first and into the second open position without lifting the third valve piston (15) from its closed position, thereby providing the first opening state of the Dosing valve, wherein the first valve piston (12) is movable from the second open position to a third open position, the first valve piston (12) engaging the third valve piston (15) and lifting the second valve piston (14) and the third valve piston (15) from their closed positions, thereby providing a third opening condition of the Dosing valve.

17. Dosing device for mixing fluids, wherein the metering device has: a frame (92) and at least one dosing valve (2, 76), wherein the Dosing valve (2, 76) is designed according to one of the preceding claims, and wherein the dosing valve (2, 76) is attached to the frame (92).

18. Method, with the method steps: use of a dosing device (90) according to claim 17 or of a dosing valve (2, 76) according to one of the preceding claims 1 - 16 in order to fill a container (94) with at least one fluid (8), wherein the fluid (8) is dosed into the container (94) by means of the dosing valve (2, 76); cleaning the nozzle (10) of the dosing valve (2, 76), wherein the cleaning takes place before and / or after the dosing of the fluid (8).

19. Method according to claim 18, characterised in that a cleaning fluid (26) used to flush the nozzle (10) of the dosing valve (2, 76) is discharged into the same container (94) into which the fluid (8) is also dosed by means of the dosing valve (2, 76).

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