Metering device and method for metering fluids

Abstract

The invention relates to a metering device (10) for metering fluids, in particular adhesives, having an actuator unit (12) with a drive element (14) and a fluidic unit (20) with a valve element (26) which is formed separately from the drive element (14). The fluidic unit (20) is detachably coupled to the actuator unit (12). The valve element (26) can be moved into an open position by means of the drive element (14). The metering device (10) has a restoring means (64) that interacts with the valve element (26) in such a way that, in a starting position of the metering device (10), the valve element (26) is in a closed position and is spaced apart from the drive element (14). The valve element (26) has an outlet-side section (42) that has a larger cross-section than a tapered section of the valve element (26) provided between the outlet-side section (42) and the drive element (14). The invention further relates to a method for metering fluids.

Description

[0001] Dosing device and method for dosing fluids

[0002] The invention relates to a dosing device for dosing fluids, in particular adhesives, comprising an actuator unit and a fluidic unit that is detachably connected to the actuator unit. Furthermore, the invention relates to a method for dosing fluids, in particular adhesives, using a dosing device.

[0003] In general, various methods are known in the field of fluid dispensing in which a precise volume is dispensed onto a substrate. Fluids can be liquid media, particularly adhesives, potting compounds, sealing and encapsulating materials, but also oils, greases, or paints.

[0004] Dosing devices are known in the art in which a fluid-filled reservoir, such as a cartridge, can be dispensed directly onto a substrate. For this purpose, a dispensing needle is attached to a dedicated adapter at the lower end of the fluid reservoir. Via an adapter at the upper end of the fluid reservoir, compressed air, for example, is applied to a piston located in the fluid reservoir. The compressed air acts on the piston, forcing the fluid from the fluid reservoir through the dispensing needle, where it can be dispensed onto the substrate in the form of a drop. The dispensed quantity depends, among other things, on the length of time the piston is pressurized with compressed air. For small dispensed quantities, the compressed air is applied to the piston in pulsed fashion.

[0005] Process-related problems arise with a so-called direct dosing device. Due to the pulsed, direct action of compressed air on the piston, air can penetrate into the fluid to be dosed through a gap between the outer wall of the piston and the inner wall of the fluid reservoir. This promotes bubble or foam formation, which leads to the dosing of air bubbles trapped in the fluid. This causes fluctuations in the dosed quantity. In addition, the fluid beneath the piston heats up, which can be exacerbated by a bouncing piston and, in turn, leads to a change in viscosity. To counteract these problems, dosing is not performed directly from the fluid reservoir. The fluid reservoir is arranged next to an actuator unit and a fluidics unit, and its lower end is connected to the fluidics unit via a fluid supply channel. This allows the fluid from the fluid reservoir to be fed into a fluid chamber via a fluid inlet.A drive element, such as a pneumatically operated plunger, extending from the actuator unit into the fluidics unit, opens or closes the valve. Constant pressure applied to the fluid reservoir forces the fluid, in the open state, from the fluid chamber to a fluid outlet. A dispensing needle is located at the fluid outlet, through which the fluid can be guided and dispensed onto the substrate. It is important for such dispensing devices that the fluidics unit can be separated from the actuator unit for cleaning, maintenance, and replacement. State-of-the-art solutions already offer solutions for this.

[0006] EP 3 096 064 A1 describes a dosing device for dosing fluids, in which the fluid reservoir is arranged next to an actuator unit and a fluidic unit. The actuator unit and the fluidic unit each have projections. A quick-connect element is configured to connect the projections of the actuator unit and the fluidic unit to one another by receiving them or to separate them from one another by releasing them.

[0007] A separation of the actuator unit and the fluidic unit also allows for a foldable fluid body housing, as shown in DE 10 2022 103 257 A1. The fluidic unit is removably accommodated when the fluid body housing is unfolded and is securely connected to the actuator unit when folded.

[0008] The disadvantage of the state-of-the-art solutions is that the dosing devices can only be cleaned with great effort.

[0009] The object of the invention is to provide a dosing device that can be cleaned effectively with little effort. A further object of the invention is to provide a method for dosing fluids using a dosing device, by means of which dosing can be carried out reliably and precisely. This object is achieved by a dosing device for dosing fluids, in particular adhesives, with an actuator unit that has a drive element, and a fluidic unit that has a valve element that is designed separately from the drive element. The fluidic unit is detachably connected to the actuator unit. Furthermore, the valve element is operatively connected to the drive element in such a way that the valve element can be adjusted into an open position by means of the drive element.The dosing device has a return means that interacts with the valve element such that, in an initial position of the dosing device, the valve element is in a closed position and is spaced apart from the drive element. Furthermore, the valve element has an output-side section that has a larger cross-section than a tapered section of the valve element provided between the output-side section and the drive element.

[0010] In state-of-the-art metering devices, a one-piece plunger, which opens and closes the valve, typically extends from the actuator unit into the fluidics unit. If such a fluidics unit is separated for cleaning, the fluid-contacting part of the plunger remains on the actuator unit and cannot be removed together with the fluidics unit for cleaning. Cleaning the plunger on the actuator unit is therefore very difficult. The risk of incomplete cleaning, cleaning agents being introduced into the actuator unit, or damage to the plunger is high.

[0011] It was recognized according to the invention that the dosing device can be cleaned reliably and without risk with little effort if the valve element that comes into contact with fluid is separated from the drive element and the valve element can thus be separated from the actuator unit together with the fluidic unit.

[0012] By forcing the valve element into the closed position, the dosing device's valve is a "normally closed" valve (NC valve). This prevents the fluid outlet from being open when the actuator unit is in a passive state, preventing fluid from accidentally escaping or dripping into the production system. This is particularly important for relatively expensive fluids. The return medium acts on the valve element in the axial direction toward the drive element.

[0013] In particular, the return means acts on the valve element to move it in the direction of the drive element.

[0014] The fluidic unit can therefore (at least partially) comprise the return means. For example, the return means rests at one end against a housing section of the fluidic unit.

[0015] The return means can be designed separately from the valve element and separately from the actuator unit, in particular separately from the drive element of the actuator unit.

[0016] Since the drive element and the valve element are designed separately from each other, the drive element and the valve element are two separate components.

[0017] In particular, the fluidic unit is connected to the actuator unit in a tool-free manner so that they can be separated quickly and easily.

[0018] In particular, the drive element acts mechanically on the valve element by the drive element contacting the valve element.

[0019] In the initial position of the dosing device, in which the valve element is in its closed position, the drive element and the valve element are spaced apart from each other. In other words, in the initial position of the dosing device, a gap is provided between the drive element and the valve element, in particular a gap along the axial direction.

[0020] In the initial position of the dosing device, the drive element does not contact the valve element. Therefore, there is no permanent connection between the drive element and the valve element.

[0021] In an active position of the dosing device, in which the drive element has been activated or the valve element is in the open position, the drive element contacts the valve element because the valve element has been moved into the open position by the drive element. The gap existing in the initial position between the drive element and the valve element has been overcome by the drive element due to the activation of the actuator unit, which results in a change in the position of the drive element. This creates the operative connection between the drive element and the valve element, which allows the drive element to move the valve element into the open position.

[0022] The drive element and the valve element only contact each other in an activated state of the dosing device, in particular the actuator unit, i.e. the active position of the dosing device or the open position of the

[0023] valve element.

[0024] In a passive state of the dosing device, i.e. in the initial position of the dosing device or the closed position of the

[0025] Valve element, the drive element and the valve element are separated from each other because they are spaced apart or the gap is provided.

[0026] The drive element and the valve element are both movable, especially in the axial direction.

[0027] Since the fluidic unit, which has at least the valve element (and the return means), is separable from the actuator unit, which has the drive element, it is ensured that the fluid outlet of the fluidic unit is closed even in the separated state.

[0028] This is because, when disconnected, the dosing device is in its initial position, in which the valve element is in the closed position. This is ensured by the return means, which is specifically assigned to the fluidic unit and thus forces the valve element into the closed position even when disconnected.

[0029] This ensures that the fluidic unit can be separated from the actuator unit.

[0030] In one embodiment, one or more sections of the valve element are circularly cylindrical, so that the cross-section corresponds to the diameter of the respective sections. In particular, the valve element is rotationally symmetrical.

[0031] In a further embodiment, the fluidic unit has a first sealing element that forms a valve seat against which the valve element rests via a valve sealing surface in the closed position. In particular, the valve sealing surface is formed in a transition area from the outlet-side section to the tapered section. This ensures that the valve closes tightly in the closed position.

[0032] Additionally or alternatively, the tapered portion of the valve element may merge into a base portion of the valve element having a larger cross-section than the tapered portion.

[0033] According to one embodiment, the base section has a cross-section which is smaller than the cross-section of the output-side section.

[0034] It is also possible for the cross-section of the outlet section to be smaller than the cross-section of the base section. In this case, the first sealing element is matched to the outlet section to ensure that the valve closes tightly in the closed position.

[0035] In an alternative embodiment, the base section has the same cross-section as the outlet-side section. This allows the valve element to be manufactured particularly cost-effectively, as the valve element can be manufactured from a circular cylindrical base body that is only machined in certain areas to form the tapered section.

[0036] In any case, the cross-section of the outlet-side section is larger than an inner diameter of the first sealing element, so that in the closed position as much of the surface of the first sealing element as possible is covered by the outlet-side section in order to ensure a tight fit of the valve element against the first sealing element.

[0037] Furthermore, the valve element can be provided with an engagement groove into which a locking element engages, limiting the movement of the valve element. In particular, the engagement groove is formed in the base section. Thus, the locking element is effectively and efficiently connected to the valve element. The locking element serves as a movement limiter for the valve element, since the movement in the open position is limited by the locking element.

[0038] The return means can be supported by the securing element and a contact element, which is arranged in the dosing device in a precise position. In particular, the valve element extends through an opening in the contact element. This ensures a defined return action and thus a reliable closed position. The contact element can be formed by a separate component or by a housing section.

[0039] According to one embodiment, the fluidic unit has a fluid supply line for the fluid to be metered, wherein the drive element is always separated from the fluid to be metered, whereas the valve element is always in contact (at least in some areas) with the fluid to be metered. This ensures that the drive element provided in the actuator unit does not need to be cleaned, as unlike the valve element of the fluidic unit, it cannot be removed.

[0040] The fluidic unit can have a fluid chamber in which the valve element is at least partially arranged. The fluid chamber is fluidly connected to the fluid supply line. Furthermore, the fluid chamber is delimited by a second sealing element. The valve element extends through an opening in the second sealing element. This ensures that the fluid chamber is tightly closed in the closed position and that, in the open position of the valve, fluid flows out of the fluid chamber essentially only via the valve seat. The second sealing element seals the fluid chamber from the actuator unit.

[0041] According to a further embodiment, the fluidic unit has at least one heating element to increase the temperature of the fluid and thus reduce its viscosity if necessary. Furthermore, the heating element can be used to keep the temperature of the fluidic unit at a constant value for particularly precise dosing, particularly independent of fluctuating ambient temperatures. The actuator unit and the fluidic unit can be connected to one another without tools using a slide-in, plug-in, bayonet, folding, or clamping mechanism, or combinations thereof. This allows the actuator unit and the fluidic unit to be effectively connected and separated from one another with little effort.

[0042] In particular, these mechanisms are designed integrally with the actuator unit and the fluidic unit, eliminating the need for additional connecting elements for connecting the fluidic and actuator units, which would otherwise significantly increase the overall weight and volume of the dosing device.

[0043] Furthermore, it can be provided that the return means is a magnetic element, an electromagnetic element or an elastic element, in particular made of an elastomer or a spring.

[0044] In a further embodiment, the tapered section merges into the outlet-side section via a transition area. The transition area is truncated cone-shaped. This gives the valve element an outer contour with low flow resistance, allowing the fluid to be metered to flow along the valve element at a defined volumetric flow rate.

[0045] Furthermore, the tapered section can transition into the base section via a step or a transition area that is truncated cone-shaped. The transition from the tapered section to the base section can thus occur via a step or a transition section that is truncated cone-shaped. The volume flow can be defined via the corresponding contour.

[0046] Preferably, there are no steps or jumps between the outlet section and the tapered section, which would be accompanied by plateaus where the fluid could accumulate. However, the transition from the tapered section to the base section can be stepped.

[0047] According to the invention, to achieve the above-mentioned object, a method for dosing fluids, in particular adhesives, using a dosing device is also provided, for example a dosing device of the type mentioned above. In this case, a valve element, in a force-loaded state of a drive element that is formed separately from the valve element, is acted upon into an open position in which a fluid outlet of a fluidic unit of the dosing device is released, so that a fluid flow is transported via the fluid outlet and along a valve sealing surface of the valve element into a fluid ejection chamber of the fluidic unit. In a force-free state of the drive element, the valve element is retracted by a return means into a closed position in which the valve element is spaced from the drive element and the valve sealing surface closes the fluid outlet, so that the fluid flow is interrupted.

[0048] The above-mentioned advantages and features with regard to the dosing device apply analogously to the dosing method, to which reference is made accordingly.

[0049] Further advantages and features are evident from the following description and the attached drawings. These show:

[0050] - Figure 1 shows a sectional view of a dosing device according to the invention with a fluidic unit and an actuator unit,

[0051] - Figure 2 shows an exploded view of the fluidic unit from Figure 1,

[0052] - Figure 3 shows a sectional view of the dosing device from Figure 1 in a

[0053] Closed position or initial position,

[0054] - Figure 4 shows a sectional view of the dosing device from Figure 1 in a

[0055] opening position,

[0056] - Figure 5 shows a side view of a valve element of the fluidic unit from Figure 1 according to an embodiment,

[0057] - Figure 6 shows a side view of the valve element of the fluidic unit from Figure 1 according to a further embodiment,

[0058] - Figure 7 shows in a perspective view the dosing device from

[0059] Figure 1 , wherein the fluidic unit is separated from the actuator unit by means of a connecting mechanism, - Figure 8 in a perspective view the dosing device from

[0060] Figure 1 , wherein the fluidic unit is connected to the actuator unit by means of the connecting mechanism, and

[0061] - Figure 9 shows a side view of the dosing device from Figure 1, with a positioning element of the plug-in mechanism being shown in a cut-out detailed view.

[0062] The following detailed description, taken in conjunction with the accompanying drawings, in which like numerals refer to like elements, is intended to describe various embodiments of the disclosed subject matter and is not intended to be the only embodiments. Each embodiment described in this disclosure is merely exemplary or illustrative and should not be construed as preferred or advantageous over other embodiments.

[0063] All features disclosed below with respect to the embodiments and / or the accompanying figures may be combined alone or in any sub-combination with features of the aspects of the present disclosure, including features of preferred embodiments, provided that the resulting combination of features is meaningful to a person skilled in the art.

[0064] Figure 1 shows a dosing device 10 for dosing fluids with an actuator unit 12 and a fluidic unit 20.

[0065] The dosing device 10 is designed for dosing fluids, in particular adhesives.

[0066] The actuator unit 12 has a drive element 14 and is configured to adjust the drive element 14 in the axial direction A.

[0067] The actuator unit 12 here is a pneumatic drive, in particular with an air pressure connection 16.

[0068] In the present embodiment, the drive element 14 is a piston, in particular made of a solid material, which is movably mounted in a cylinder sleeve 18 in the axial direction A. In an alternative embodiment, the actuator unit 12 can be a hydraulic, electrical, piezoelectric, or electromagnetic actuator unit.

[0069] The fluidic unit 20 has a fluid housing 22 with a fluid chamber 24, a valve element 26 which extends in the axial direction A through the fluid chamber 24, and a fluid supply line 28 which opens into the fluid chamber 24.

[0070] The fluid supply line 28 has an external fluid connection 30 for a fluid reservoir 32, by means of which the fluid to be dosed can be provided.

[0071] In the illustrated embodiment, the fluid reservoir 32 is a separately formed cartridge. The fluid reservoir 32 can be pressurized, so that the fluid contained in the fluid reservoir 32 is forced toward the fluid port 30.

[0072] The fluid chamber 24 is delimited in the axial direction A by a first sealing element 34 and in the opposite direction by a second sealing element 36.

[0073] The sealing elements 34, 36 are annular sealing elements (see Figure 2), for example O-rings.

[0074] The two sealing elements 34, 36, in particular their openings, are aligned in plan view of the sealing elements 34, 36, i.e. along an axial direction A.

[0075] The first sealing element 34 forms a valve seat 38 of a valve 40 (see Figure 3), which is formed by the valve element 26 and the first sealing element 34.

[0076] In this context, the valve 40 is adjustable by means of the actuator unit 12 between a closed position (see Figure 3), in which the valve element 26 closes the valve seat 38, and an open position (see Figure 4), in which the valve element 26 releases the valve seat 38 so that fluid can flow out of the fluid chamber 24. The valve element 26 (see Figure 5) has an output-side section 42, which is assigned to an end of the valve element 26 opposite the drive element 14, a base section 44, which is provided in the axial direction A between the drive element 14 and the output-side section 42, and a tapered section 46, which is provided in the axial direction A between the base section 44 and the output-side section 42.

[0077] In the present embodiment, sections 42, 44, 46 are each circularly cylindrical. This means that sections 42, 44, 46 each have a circular cross-section perpendicular to the axial direction A.

[0078] In the following, reference is therefore made to the cross-sections of sections 42, 44, 46 via the corresponding diameter.

[0079] In principle, the sections 42, 44, 46 can each be designed as desired and each have one or more cross sections of any size and / or shape, as long as the function of the valve 40 described later is ensured.

[0080] As shown in Figure 5, the output-side section 42 has a diameter D1, the base section 44 has a diameter D2, and the tapered section 46 has a diameter D3, each of which is smaller than the diameter D1 of the output-side section 42 and the diameter D2 of the base section 44.

[0081] The diameter D1 of the outlet-side section 42 is larger than the inner diameter of the opening 48 of the first sealing element 34 through which the valve element 26 extends in the axial direction A.

[0082] In one embodiment, the diameter D1 of the output-side section 42 is, for example, at least 110% of the inner diameter of the opening 48 of the first sealing element 34 in order to reliably close the opening 48 of the first sealing element 34 in the closed position.

[0083] The diameter D2 of the base portion 44 is at least as large as the inner diameter of the opening 50 of the second sealing element 36, through which the base portion 44 extends in the axial direction A in all operating positions of the valve 40.

[0084] The diameter D3 of the tapered portion 46 is smaller than the inner diameter of the opening 48 of the first sealing element 34, in particular at least 10% smaller.

[0085] In the present embodiment according to Figure 5, the outlet-side section 42 and the base section 44 have the same diameter, i.e., D1 = D2, whereby the valve element 26 can be manufactured particularly cost-effectively, since it can be made from a circular-cylindrical base body having the diameters D1 and D2, respectively. The tapered section 46 has a smaller diameter than the outlet-side section 42 and the base section 44, which is why it can be easily manufactured by machining the base body, for example, by turning, milling, or other techniques.

[0086] In this case, i.e. when D1 = D2, the inner diameter of the opening 48 of the first sealing element 34 is smaller than the inner diameter of the opening 50 of the second sealing element 36.

[0087] In an alternative embodiment, the diameter D1 of the output-side section 42 is larger than the diameter D2 of the base section 44.

[0088] In principle, the output-side section 42 and the base section 44 can each have any desired diameter D1, D2, as long as it is larger than the diameter D3 of the tapered section 46.

[0089] In other words, in an alternative embodiment, the diameter D1 of the outlet-side section 42 can be smaller than the diameter D2 of the base section 44. The first sealing element 34, in particular the inner diameter of the opening 48, must then be adapted accordingly to the outlet-side section 42.

[0090] The tapered section 46 is connected in the axial direction A to the outlet-side section 42 via a conical first transition region 52, whereby the diameter of the valve element 26 increases continuously from diameter D3 to diameter D1. This prevents a step or a ledge, so that the fluid cannot accumulate on a plateau.

[0091] The base section 44 is connected in the axial direction A to the tapered section 46 via a conical second transition region 54, whereby the diameter of the valve element 26 decreases continuously from the diameter D2 to the diameter D3.

[0092] The transition areas 52 and 54 are each designed in the shape of a truncated cone.

[0093] In principle, the transition regions 52 and 54 can each be designed as desired. Preferably, however, at least the diameter of the first transition region 52 changes continuously in the axial direction A.

[0094] The transition regions 52 and 54 are also optional and can thus be omitted in alternative embodiments.

[0095] For example, in an alternative embodiment, the valve element 26 may not have a transition region 54, so that the base section 44 adjoins the tapered section 46 via a step. As a result, in the open position, a particularly large area remains free between the opening 48 of the first sealing element 34 and the section through which the fluid supply line 28 opens into the fluid chamber 24, thus ensuring a particularly large volume flow.

[0096] In this context, the first transition region 52 forms a valve sealing surface 56, via which the valve element 26 lies tightly against the valve seat 38 in the closed position of the valve 40 and effectively closes it.

[0097] The valve sealing surface 56 is therefore provided on a side of the first transition region 52 which faces the drive element 14 or the tapered section 46.

[0098] In embodiments in which the valve element 26 does not have a first transition region 52, the output-side section 42 forms the valve sealing surface 56. In the open position, the valve sealing surface 56 is arranged at a distance from the valve seat 38 in the axial direction A and the tapered section 46 extends through the opening 48 of the first sealing element 34, as shown in Figure 4.

[0099] The first sealing element 34 forms a fluid outlet F of the valve 40.

[0100] In the present embodiment, the output-side section 42 forms an axial output-side end 58 of the valve element 26, i.e. the end associated with the valve output.

[0101] In an alternative embodiment (see Figure 6), the valve element 26 has an axial outlet-side end 58 which tapers continuously in the axial direction A from the outlet-side section 42 to a tip 60.

[0102] A tip 60 designed in this way promotes advantageous flow properties and, above all, dripping properties of the fluid to be dosed at the outlet end 58.

[0103] Opposite the output end 58, the valve element 26 has an axial drive-side end 62, which is formed here by the base portion 44.

[0104] The drive element 14 acts on the valve element 26 via the drive-side end 62 in order to move the valve 40 into the open position.

[0105] In order to move the valve 40 from the open position to the closed position, which forms an initial position of the valve 40, the fluidic unit 20 has a return means 64 which acts on the valve element 26 opposite to the axial direction A towards the drive element 14.

[0106] The force of the return means 64 is large enough to ensure a tight closure of the valve seat 38 and smaller than the force applied by the actuator unit 12 to adjust the valve element 26 by means of the drive element 14 in the axial direction A into the open position of the valve 40.

[0107] In other words, the valve 40 is a normally closed valve whose closed initial position is ensured by the return means 64. In the present embodiment, the return means 64 is a coil spring clamped between a contact element 66 and a securing element 68.

[0108] The contact element 66 is here a section of the fluid housing 22.

[0109] In an alternative embodiment, the contact element 66 can be formed by a separate component which in particular directly or indirectly rests against the fluid housing 22 or is connected thereto.

[0110] The securing element 68 engages in an engagement groove 70 on the base portion 44 and is thus coupled to the valve element 26 in the axial direction A.

[0111] The securing element 68 is, for example, a (slotted) clamping or securing ring, which can be attached in particular without tools.

[0112] In this context, the base portion 44 extends in the axial direction A through an opening 72 in the portion of the fluid housing 22 forming the contact element 66, whereby the engagement groove 70, the securing element 68 and the return means 64 are arranged on the outside of the fluid housing 22.

[0113] In particular, the drive-side end 62 is arranged outside the fluid housing 22 and is always separated from the fluid to be dosed via the second sealing element 36.

[0114] In principle, the return means 64 can be designed in any way, for example in the form of a magnetic element, an electromagnetic element or an elastic element made of an elastomer or in the form of a spring.

[0115] The method for dosing a fluid using the dosing device 10 is described below.

[0116] In the initial position, valve 40 is closed.

[0117] The fluid chamber 24 and the fluid supply line 28 are already filled with the fluid to be metered, which is provided via the fluid reservoir 32 under a pressure, in particular a constant pressure. In order to move the valve 40 from the closed position to the open position, the drive element 14 is pressed in the axial direction A against the drive-side end 62 of the valve element 26 with a force such that the force of the return means 64 is overcome and the valve element 26 is moved in the axial direction A. As a result, the fluid outlet F opens and the fluid flows from the fluid chamber 24 between the first sealing element 34 and the tapered section 46, over the valve sealing surface 56 and the outlet-side section 42 into a fluid ejection chamber 74 of the fluidic unit 20. In other words, the valve element is moved from the valve seat 38 in the direction of the fluid ejection chamber 74.

[0118] In the illustrated embodiment, the fluid in the fluid ejection chamber 74 is dispensed in a precisely positioned manner by means of a fluid ejection element 76, for example a dispensing needle or nozzle, which is fastened to the fluid housing 22 via an adapter 78 and is fluidly connected to the fluid ejection chamber 74.

[0119] To ensure a constant viscosity and, consequently, a constant volume flow, the dosing device 10 can have a heating element 80 (see Figure 1) for controlling the temperature of the fluidic unit 20. In this way, the fluidic unit 20 and the fluid flowing through it can be heated to a defined temperature. Figure 1 shows that the heating element 80 is arranged on the actuator unit 12, with a corresponding heat conduction to the fluidic unit 20 being provided.

[0120] In an alternative embodiment, the heating element 80 is attached directly to the fluidic unit 20.

[0121] In both cases, this ensures that the fluid to be dosed can be heated via the heating element 80.

[0122] In order to move the valve 40 from the open position to the closed position, the force with which the drive element 14 is pressed against the valve element 26 is canceled or reduced to such an extent that the valve element 26 is pulled by the return means 64 against the axial direction A. In this case, the valve sealing surface 56 presses against the valve seat 38 with a force which is so great that the fluid outlet F is tightly closed and the fluid flow is interrupted.

[0123] In this way, the drive element 14 never comes into contact with the fluid to be dosed, while during operation the fluid to be dosed always contacts the valve element 26 in sections.

[0124] To clean the dosing device 10, it is therefore sufficient to clean the fluidic unit 20.

[0125] For this purpose, the fluidic unit 20 is detachably connected to the actuator unit 12 via a connecting mechanism 82 (see Figures 7 and 8) so that the fluidic unit 20 can be removed, in particular for cleaning.

[0126] In the present embodiment, the connecting mechanism 82 is formed by an insertion mechanism with a guide 84 in a housing section 86 of the actuator unit 12 and an insertion element 88 complementary to the guide 84, which is part of the fluid housing 22.

[0127] As a result, the insertion element 88 can be inserted into the guide 84 in the insertion direction X in order to transfer the fluidic unit 20 with the actuator unit 12 into a connected state (see Figure 8) in which these forms are connected to one another.

[0128] From the connected state, the fluidic unit 20 and the actuator unit 12 can be transferred into a separated state (see Figure 7) by pulling the insertion element 88 out of the guide 84 opposite to the insertion direction X.

[0129] The connection mechanism 82 is particularly designed such that no tool is required to connect the fluidic unit 20 to the actuator unit 12 or to separate the fluidic unit 20 from the actuator unit 12.

[0130] In order to ensure a defined position of the fluidic unit 20 relative to the actuator unit 12, the actuator unit 12 has two positioning elements 90 projecting into the guide 84 and the insertion element 88 has two recesses 92 which are designed to be complementary to the two positioning elements 90.

[0131] Additionally or alternatively, the positioning elements 90 can be configured to secure the fluidic unit 20 from falling out.

[0132] The dosing device 10 is designed such that the positioning elements 90 each engage in a recess 92 (see Figure 9) when the fluidic unit 20 is inserted into the actuator unit 12 in a defined manner.

[0133] Of course, in an alternative embodiment, any number of positioning elements 90 and complementarily designed recesses 92 can be provided.

[0134] The positioning elements 90 can be designed to be elastic so that they are displaced from the guide 84 when the fluidic unit 20 is pushed in and pulled out, in order to facilitate the connection and separation of the fluidic unit 20 and the actuator unit 12.

[0135] In principle, the connection mechanism 82 can be designed in any way, for example by means of a slide-in, plug-in, bayonet, folding or clamping mechanism or combinations thereof.

[0136] In this way, a dosing device 10 is provided which can be cleaned with little effort.

[0137] By making the drive element 14 and the valve element 26 separate components, it is ensured that the drive element 14 does not come into contact with the fluid to be metered during operation. This eliminates the need for time-consuming cleaning of the actuator unit 12.

[0138] Furthermore, this provides a method for particularly precise dosing of fluids.

[0139] The design of the valve 40, in which the valve element 26 extends in the axial direction A through the valve seat 38 and closes it with the valve sealing surface 56 in the closed position, ensures that the valve 40 is tightly closed in the closed position and thus no fluid drips. Furthermore, the tapered section 46 of the valve element 26 ensures that a defined volume flow always flows through the fluid outlet F in the open position.

Claims

Patent claims 1. A dosing device (10) for dosing fluids, in particular adhesives, comprising an actuator unit (12) having a drive element (14), and a fluidic unit (20) having a valve element (26) formed separately from the drive element (14), wherein the fluidic unit (20) is detachably connected to the actuator unit (12), wherein the valve element (26) is operatively connected to the drive element (14) in such a way that the valve element (26) can be adjusted into an open position by means of the drive element (14), wherein the dosing device (10) has a return means (64) which cooperates with the valve element (26) in such a way that the valve element (26) is in a closed position in an initial position of the dosing device (10) and is spaced from the drive element (14), and wherein the valve element (26) has an output-side section (42), which has a larger cross-section (D1) than a tapered section (46) of the valve element (26),which is provided between the output-side section (42) and the drive element (14).

2. Dosing device (10) according to claim 1, characterized in that the fluidic unit (20) has a first sealing element (34) which forms a valve seat (38) against which the valve element (26) rests via a valve sealing surface (56) in the closed position, in particular wherein the valve sealing surface (56) is formed in a transition region (52) from the outlet-side section (42) to the tapered section (46).

3. Dosing device (10) according to claim 1 or 2, characterized in that the tapered section (46) of the valve element (26) merges into a base section (44) of the valve element (26) which has a larger cross-section (D2) than the tapered section (46).

4. Dosing device (10) according to one of the preceding claims, characterized in that the valve element (26) has an engagement groove (70) into which a securing element (68) engages, which limits the movement of the valve element (26), in particular wherein the engagement groove (70) is formed in the base section (44).

5. Dosing device (10) according to claim 4, characterized in that the return means (64) is located on the securing element (68) and a Supporting element (66) which is arranged in the dosing device (10) in a positionally accurate manner, in particular wherein the valve element (26) extends through an opening (72) in the contact element (66).

6. Dosing device (10) according to one of the preceding claims, characterized in that the fluidic unit (20) has a fluid supply line (28) for the fluid to be dosed, wherein the drive element (14) is always separated from the fluid to be dosed, whereas the valve element (26) is always in contact with the fluid to be dosed.

7. Dosing device (10) according to claim 6, characterized in that the fluidic unit (20) has a fluid chamber (24) in which the valve element (26) is at least partially arranged, wherein the fluid chamber (24) is fluidly connected to the fluid supply line (28), wherein the fluid chamber (24) is delimited by a second sealing element (36), and wherein the valve element (26) extends through an opening (50) of the second sealing element (36).

8. Dosing device (10) according to one of the preceding claims, characterized in that the fluidic unit (20) has at least one heating element (80).

9. Dosing device (10) according to one of the preceding claims, characterized in that the actuator unit (12) and the fluidic unit (20) are connected to one another in a tool-free manner by means of an insertion, plug-in, bayonet, folding or clamping mechanism (82) or combinations thereof.

10. Dosing device (10) according to one of the preceding claims, characterized in that the return means (64) is a magnetic element, an electromagnetic element or an elastic element, in particular made of an elastomer or a spring.

11. Dosing device (10) according to one of the preceding claims, characterized in that the tapered section (46) merges into the outlet-side section (42) via a transition region (52), wherein the transition region (52) is frustoconical.

12. Dosing device (10) according to one of the preceding claims, characterized in that the tapered section (46) merges into the base section (44) via a step or transition region (54) that is frustoconical in shape.Method for dosing fluids, in particular adhesives, using a dosing device (10), wherein a valve element (26) is acted upon in a force-loaded state of a drive element (14), which is formed separately from the valve element (26), into an open position in which a fluid outlet (F) of a fluidics unit (20) of the dosing device (10) is released, so that a fluid flow is transported via the fluid outlet (F) and along a valve sealing surface (56) of the valve element (26) into a fluid ejection chamber (74) of the fluidics unit (20), wherein the valve element (26) is retracted by a return means (64) into a closed position in which the valve element (26) is spaced from the drive element (14) and the valve sealing surface (56) closes the fluid outlet (F), so that the fluid flow is interrupted.

Images