EP3165288B1 - Jet device - Google Patents

Description

The present invention relates to a spray device for spraying a fluid.

The spraying of fluids or fluid media, such as, for example, adhesives or sealants, paints, suspensions, viscous raw materials, emulsions or fats, can take place, for example, with the aid of a spray device based on the Venturi effect. A Venturi nozzle comprises a smooth-walled pipe section with a narrowing of the cross section, for example by two cones directed towards one another, which are combined at the point of their smallest diameter. A pick-up pipe is placed at this point, through which the fluid to be sprayed can be supplied. The supplied fluid is entrained and sprayed with the aid of a gas flowing through the venturi nozzle, for example air.

The CH 699 808 A1 shows a spray device with a spray head for spraying at least one component. The spray device comprises at least one component channel, the component outlet of which opens out from a spray head tip. An annular channel for a compressed gas at least partially surrounds the at least one component channel in the longitudinal direction and opens out of the spray head at the spray head tip. A pressurized gas supply channel is provided for introducing pressurized gas into the ring channel. The annular channel has several webs which subdivide the annular channel at least in the region of the spray head tip into separate compressed gas outlet channels.

The WO 2013/171029 A1 shows a multi-component cartridge for receiving flowable components that are to be applied with a spraying process, with a first container for receiving a first component, a second container for receiving a second component and at least one cartridge outlet opening through which the components exit the containers can, a cartridge compressed air channel guided along the container with a cartridge compressed air inlet and a cartridge compressed air outlet, wherein the first container, the second container and the cartridge compressed air channel are made in one piece.

The U.S. 5,020,723 A Figure 12 shows an apparatus for spraying adhesive, having a housing which has inner and outer surfaces, an inlet through which adhesive can be introduced, and an opening through which adhesive can exit. The device further comprises a nozzle for spraying adhesive, which is fluidly connected to the housing, an air cap which has an opening aligned with the nozzle through which compressed air and adhesive can exit, and means which define a first passage around a To cause rotation of the compressed air and define a second flight fluidly connected to the first flight and having a polygonal inner boundary and a circumferential boundary to allow the rotating air to spiral helically.

The WO 2005/102538 A1 shows a device for spraying flowable spray fluids with at least one fluid reservoir comprising at least one wall for storing the spray fluid, a spray opening being provided for the outflow of the spray fluid from the device, the wall of the fluid reservoir comprising at least one adjustable wall area for changing the reservoir volume of the fluid reservoir .

The U.S. 4,996,091 A , the WO 2012/012169 A1 , the JP 2008 289986 A , the U.S. 2,555,238 A and the FR 2 971 531 A1 show further devices for spraying fluids.

Against this background, it is an object of the present invention to provide an improved spray device.

Accordingly, a spray device for spraying a fluid is proposed. The spray device comprises a metering device, which is an eccentric screw pump is, for volumetric metering of the fluid and a spray device which is set up to spray the fluid metered by the metering device with the aid of a gas. The spray device further comprises a spray head with a gas cap and a metering needle, from which the metered fluid exits and which is passed through the gas cap, the metering needle protruding in a longitudinal direction of the spray device over the gas cap, behind it or being flush with it and where the dispensing needle and / or the gas cap are adjustable in length. The spray head comprises a swirl element for swirling the gas, the swirl element being made of a porous plastic, ceramic or metal material.

The metering device is in particular a first metering device of the spray device. The spray device can comprise several, for example two, metering devices. The metering device preferably comprises a stator which is received in a pump housing of the metering device and which has an elastically deformable elastomer part with a central opening. The opening preferably comprises a helical or worm-shaped inner contour. A rotatable rotor is preferably provided in the stator, which rotor comprises a helical or worm-shaped outer contour corresponding to the elastomer part. The rotor can be driven via a drive shaft mounted in a bearing housing of the metering device. A drive device, in particular an electric motor, can preferably be connected to the drive shaft. The drive shaft can be firmly connected to the rotor with the aid of a flexible shaft or flex shaft. When the rotor rotates, the fluid is conveyed away from the drive shaft according to the endless piston principle in a longitudinal direction of the spray device due to the interaction with the elastomer part of the stator. The delivery volume depends on the speed and size of the rotor.

Volumetric dosing is understood to mean that the fluid is discharged exclusively in relation to volume and thus quantity. In contrast to this, with a gravimetric or weight-controlled dosing system this becomes too dosing fluid weighed with a weighing device. A temperature sensor can optionally be used to determine a temperature of the fluid. The temperature sensor can be provided in the fluid or in the pump housing. With the help of the fluid temperature determined by the temperature sensor, the delivery volume can be readjusted. In this way, changes in the volume of the fluid caused by heat are compensated and metering inaccuracies are avoided.

The fluid can be, for example, an adhesive or sealant, water, an aqueous solution, a paint, a suspension, a viscous raw material, an emulsion, or a fat. The fluid can have one or more than one component. For example, the fluid can be a two-component adhesive. The gas is preferably air. The gas can also be oxygen, carbon dioxide, nitrogen, a noble gas or some other gas. Because the fluid is dosed volumetrically, it can be sprayed with great precision. In particular, the dosing of the fluid can take place independently of the spraying of the same. The Venturi effect is not used to spray the fluid. This prevents the fluid from being torn out of a metering needle of the metering device. This prevents the formation of blobs or islands on a substrate to be sprayed.

Because the fluid can be dosed volumetrically and independently of the gas supply, the gas can be switched on before the fluid is dosed and only switched off again after the dosing has ended. This means that the amount of fluid metered in with the metering device can be slowly increased up to the desired metered amount when the gas is switched on and can also be continuously reduced again when the gas is still switched on. This enables the spraying process to be started up and ended like a ramp. In particular, the volume flow of the fluid and the volume flow of the gas can be regulated independently of one another. As a result, the spray pattern can be varied to a large extent.

A method for operating the spray device comprises one, in particular a first, step of volumetric metering of the fluid and a, in particular second, step of spraying the metered fluid with the aid of the gas. The steps can be carried out simultaneously or at different times.

According to one embodiment, the spray device further comprises a heating and / or cooling device for heating or cooling the fluid in order to change its viscosity.

In particular, by heating or cooling the fluid, its spray properties can be changed. For example, a highly viscous fluid can be heated in this way in order to reduce its viscosity. Alternatively, a low viscosity fluid can be cooled to increase its viscosity. This makes it possible to spray both low-viscosity and high-viscosity fluids. A control device of the spray device can readjust the metering of the fluid with the aid of the determined temperature of the fluid with access to a viscosity table stored in the control device. In this way, metering inaccuracies due to thermal expansion of the fluid can be prevented.

According to a further embodiment, the heating and / or cooling device is arranged in a pump housing of the metering device.

Alternatively, the heating and / or cooling device can be arranged on the outside of the pump housing in the form of a sleeve. The heating and / or cooling device further comprises a temperature sensor, which is preferably also arranged in the pump housing. The heating and / or cooling device also comprises a printed circuit board or circuit board on which heating and / or cooling elements such as heating cartridges and / or Peltier elements are arranged. A plug for connecting the heating and / or cooling device to the control device of the spray device can also be provided on the circuit board. The spray device comprises a spray head with a gas cap and a dosing needle, which is guided through the gas cap, the dosing needle protruding beyond the gas cap in a longitudinal direction of the spray device.

The dispensing needle can also be flush with the gas cap or shorter than it. This means that the dispensing needle can protrude behind the gas cap. For example, the dispensing needle can protrude 0 to 1 mm behind the gas cap. The spray head preferably further comprises an air or gas housing with a gas supply line. The gas supply line can comprise a quick-release fastener for connecting a gas line. The air or gas cap is preferably fastened to the gas housing with the aid of a union nut. The union nut can have knurling on the outside, so that it can be unscrewed without tools. The gas cap is particularly exchangeable for adaptation to different fluids and / or for changing the spray pattern. The gas cap preferably has a conical bore in which the metering needle, which is preferably also conical on the outside, is arranged. The dispensing needle and / or the gas cap can be surface-treated, in particular surface-coated, hardened or passivated. In particular, the metering needle and / or the gas cap can be surface-treated in such a way that very reactive and / or abrasive fluids can also be sprayed. For example, the gas cap on the inside and / or the metering needle on the outside can have a diamond-like amorphous carbon coating (Diamond-Like Carbon, DLC). In particular, the metering needle protrudes beyond the gas cap with a predetermined protrusion. The predetermined protrusion can be, for example, 0 to 1 mm. This means that the dispensing needle can also be flush with the gas cap. The overhang can be changeable. Because the dosing needle protrudes beyond the gas cap, it is also possible, in addition to spraying the fluid, to dose it directly onto a substrate. Furthermore, the dispensing needle can be negatively charged and the substrate can be electrically charged positively or vice versa. This results in a better spray pattern, better edge sharpness and less blob formation.

According to a further embodiment, a circumferential gap for the gas is provided between the gas cap and the metering needle.

The gap preferably envelops the dispensing needle in the form of a jacket. A ring-shaped circumferential gas channel for distributing the gas is preferably provided in the gas housing.

The spray head comprises a swirl element for swirling the gas.

The vortex element can be provided in the circumferential gap. More than one vortex element can be provided. For example, screw-shaped or spiral-shaped ribs and / or screw-shaped or spiral-shaped milled recesses, which are designed to swirl the gas, can be provided on the metering needle and / or on the gas cap. This causes the gas to exit the spray head with a twist. This results in a sharper-edged and more even spray pattern.

The vortex element is made of a porous plastic, ceramic or metal material.

The vortex element can be made of a sintered ceramic or metal material, for example. For example, the vortex element can be made of aluminum or steel. The gas preferably flows through the vortex element. In particular, the entire gap between the metering needle and the gas cap is filled with the porous vortex element. The vortex element can be in one piece or in several pieces. The gas flows through the vortex element. With the help of the vortex element, the gas can be swirled indefinitely, that is, chaotically.

According to a further embodiment, the metering needle is connected to an end piece of the metering device in one piece or in a form-fitting manner. The end piece is preferably firmly connected to the pump housing, for example screwed. The stator can be clamped between the pump housing and the end piece. For example, the metering needle can be screwed into the end piece. This makes it easy to exchange the dispensing needle. Alternatively, the metering needle can be made in one piece with the end piece. In this way, dead space optimization can be achieved. This is particularly advantageous in the case of a filigree design of the spray head. Both the metering needle and the gas cap are preferably interchangeable.

The metering needle and / or the gas cap are adjustable in length.

The gas cap preferably has a gas pipe, the length of which can be adjusted, for example, with the aid of a locking screw connection. Because the length of the gas cap is adjustable, the protrusion of the dispensing needle can be adjusted over the gas cap. In this way, a spray angle of the spray device can be set without replacing components. Optionally, the gas cap can have a tubular gas cap extension. The length of the gas cap extension is preferably arbitrary. The dosing needle can have a dosing needle extension which corresponds to the gas cap extension and which preferably protrudes in the longitudinal direction beyond the gas cap extension. Furthermore, the dispensing needle can be designed as an exchangeable, disposable component. In particular, the dispensing needle can be a disposable cannula. The metering needle can have a connection body made of a plastic material and a cannula. The connection body preferably has an inner cone into which a corresponding outer cone of the end piece can be inserted. The inner cone and the outer cone can form a Luer lock connection. As a result, the dispensing needle can be exchanged particularly easily and quickly.

According to a further embodiment, the metering device is set up for the volumetric metering of a first component of the fluid, the spray device being a further metering device, in particular an eccentric screw pump, for volumetric metering of a second component of the fluid.

In particular, a spray device for spraying a fluid with a first metering device, in particular a first eccentric screw pump, for volumetric metering of a first component of the fluid, a second metering device, in particular a second eccentric screw pump, for volumetric metering of a second component of the fluid and a spray device is proposed, which is set up to spray the fluid with the aid of a gas. The spray device is preferably a common spray device of the first metering device and the second metering device. In particular, the spray device is set up to spray the first component metered by the first metering device and the second component of the fluid metered by the second metering device with the aid of the gas. In addition to the first component and the second component, the fluid can comprise further components. The fluid can be a two-component adhesive, for example. The components can be mixed to form the fluid either before the spraying or during the spraying.

According to a further embodiment, the spray device comprises a mixing chamber for mixing the first component of the fluid with the second component of the fluid before spraying the fluid with the aid of the spray device.

The mixing chamber is particularly suitable for mixing ratios of the components of 1: 1 to 1: 5. Alternatively, the mixing chamber can be dispensed with.

According to a further embodiment, the spray device further comprises a mixing element arranged in the mixing chamber for dynamic mixing of the first component of the fluid with the second component of the fluid.

The mixing element can also be referred to as a dynamic mixing element. The mixing element is preferably rotatably arranged in the mixing chamber. In particular, the mixing element is driven via a mixing element drive shaft. The mixing element drive shaft can be driven, for example, by means of an electric motor. By using the rotatable mixing element, mixing ratios of the components of the fluid of, for example, 1: 1 up to 1: 100 can be achieved.

According to a further embodiment, the spray device further comprises a static mixer arranged in the mixing chamber for mixing the first component of the fluid with the second component of the fluid.

A static mixer is a built-in part that achieves the desired mixing and dispersion effects by flowing the components of the fluid through rigid mixing elements.

According to a further embodiment, the spray device further comprises a spray head with a metering needle which is set up to mix the first component of the fluid with the second component of the fluid.

The metering needle can be made in several parts. In particular, the metering needle comprises an inner part with a central first fluid channel through which the first component of the fluid is conveyed. The metering needle can furthermore comprise an outer part which is pushed onto the inner part. A second fluid channel through which the second component of the fluid is conveyed can be provided between the inner part and the outer part. The second fluid channel envelops the inner part in the form of a jacket. This means that when the components of the fluid are dispensed, they are not mixed but rather emerge from the front side of the dispensing needle as two components. The components are mixed in that the components are swirled and mixed with the aid of the gas during spraying.

According to a further embodiment, the metering needle comprises a static mixing element.

The static mixing element can also be referred to as a static mixer. The static mixer can be provided in the dispensing needle. That is, the first component and the second component are mixed in the metering.

Further possible implementations of the spray device also include combinations, not explicitly mentioned, of features or embodiments described above with regard to the exemplary embodiments. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the spray device.

• Fig. 1 zeigt eine schematische perspektivische Ansicht einer Ausführungsform einer Sprühvorrichtung;
• Fig. 2 zeigt eine schematische Seitenansicht der Sprühvorrichtung gemäß Fig. 1;
• Fig. 3 zeigt eine schematische Rückansicht der Sprühvorrichtung gemäß Fig. 1;
• Fig. 4 zeigt eine schematische Schnittansicht der Sprühvorrichtung gemäß der Schnittlinie A - A der Fig. 2;
• Fig. 5 zeigt eine schematische Schnittansicht der Sprühvorrichtung gemäß der Schnittlinie B - B der Fig. 3;
• Fig. 6 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 7 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 8 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 9 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 10 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 11 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 12 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 13 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung;
• Fig. 14 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung; und
• Fig. 15 zeigt eine schematische Schnittansicht einer weiteren Ausführungsform einer Sprühvorrichtung.

Further advantageous refinements and aspects of the spray device are the subject matter of the subclaims and the exemplary embodiments of the spray device described below. In the following, the spray device is explained in more detail on the basis of preferred embodiments with reference to the attached figures.

• Fig. 1 shows a schematic perspective view of an embodiment of a spray device;
• Fig. 2 shows a schematic side view of the spray device according to Fig. 1 ;
• Fig. 3 shows a schematic rear view of the spray device according to FIG Fig. 1 ;
• Fig. 4 shows a schematic sectional view of the spray device according to the section line A - A of FIG Fig. 2 ;
• Fig. 5 shows a schematic sectional view of the spray device according to the section line B - B of FIG Fig. 3 ;
• Fig. 6 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 7 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 8 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 9 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 10 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 11 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 12 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 13 shows a schematic sectional view of a further embodiment of a spray device;
• Fig. 14 shows a schematic sectional view of a further embodiment of a spray device; and
• Fig. 15 shows a schematic sectional view of a further embodiment of a spray device.

In the figures, elements that are the same or have the same function have been provided with the same reference symbols, unless otherwise stated.

The Fig. 1 shows a schematic perspective view of an embodiment of a spray device 1 for spraying a fluid. The Fig. 2 shows a schematic side view of the spray device 1. The Fig. 3 shows a schematic rear view of the spray device 1. The Fig. 4 shows a schematic sectional view of the spray device 1 according to the section line A - A of FIG Fig. 2 and the Fig. 5 shows a schematic sectional view of the spray device 1 according to the section line B - B of FIG Fig. 3 . In the following, the Figs. 1 to 5 simultaneously referred to.

The spray device 1 is set up to dose and spray fluids or fluid media such as adhesives or sealants, paints, suspensions, viscous raw materials, emulsions or fats. The fluid can be single-component or multi-component. The spray device 1 comprises a, in particular a first, metering device 2 for volumetric metering of the fluid. Volumetric dosing is understood to mean that the fluid is discharged exclusively in relation to volume and thus quantity. In contrast to this, in a gravimetric or weight-controlled dosing system, the fluid to be dosed is weighed with a weighing device.

The metering device 2 is an eccentric screw pump. The spray device 1 comprises a symmetry or central axis Mi and a longitudinal direction L ₁ oriented in the direction of the central axis Mi. The metering device 2 comprises a drive shaft 4 rotatably mounted in a bearing housing 3. The drive shaft 4 is a hollow shaft. The drive shaft 4 is preferably made of a steel material and the bearing housing 3 is preferably made of a metal material, such as aluminum or steel, or a plastic material. The drive shaft 4 is rotatably supported in the bearing housing 3 with the aid of roller bearings 5, 6. The roller bearings 5, 6 can be designed as double-row angular contact ball bearings. The roller bearings 5, 6 are with the help of a locking ring 7 in the axial direction secured in the bearing housing 3. A drive device, in particular an electric motor, can be connected to the drive shaft 4. The drive device can be coupled to the drive shaft 4 with the aid of a claw coupling 8. The claw coupling 8 can be made of an elastomer material.

The drive shaft 4 is also passed through a seal housing 9 firmly connected to the bearing housing 3. The bearing housing 3 and the seal housing 9 can be designed to be rotationally symmetrical to the central axis M ₁ . A plurality of sealing devices 10 to 12 arranged one behind the other are accommodated in the seal housing 9. The sealing devices 10 to 12 can be shaft sealing rings, for example. The bearing housing 3 is by means of fastening means 13, of which in the Fig. 3 and 4th only one is provided with a reference number, screwed to the seal housing 9. The fastening means 13 can for example be hexagon socket screws. A sealing element 14 can be provided between the bearing housing 3 and the sealing housing 9. The sealing element 14 can be an O-ring. The seal housing 9 is preferably made of a metal material such as aluminum or steel, or a plastic material.

The metering device 2 further comprises a pump housing 15. The pump housing 15 is preferably made of a metal material, such as aluminum or steel, or a plastic material. The pump housing 15 can also be designed to be rotationally symmetrical to the central axis M ₁ . A sealing element 16, in particular an O-ring, can be arranged between the sealing housing 9 and the pump housing 15. The pump housing 15 can be firmly connected, in particular screwed, to the bearing housing 3 and / or the seal housing 9. The seal housing 9 is arranged between the bearing housing 3 and the pump housing 15.

A stator 17 is arranged in the pump housing 15. The stator 17 comprises a tubular outer part 18, which is preferably made of a metal material such as aluminum or steel, or a plastic material such as polyethylene or polypropylene, is made, and an elastomer part 19 which is made of an elastomer material. The outer part 18 can also be referred to as a stator casing or stator tube. The elastomer part 19 has a central opening with a helical or helical inner geometry or inner contour. The stator 17 is secured against rotation in the pump housing 15 with the aid of a feather key or a fitting pin 20. The stator 17 is arranged between a shoulder 21 provided in the pump housing 15 and an end piece 22 of the metering device 2. The end piece 22 is preferably made of a metal material such as aluminum or steel, or a plastic material. The end piece 22 is screwed to the pump housing 15, for example. The stator 17 is axially clamped in the longitudinal direction L ₁ between the pump housing 15 and the end piece 22.

A rotatable rotor 23 is arranged in the stator 17. The rotor 23 can be made of steel, aluminum or a plastic material. The rotor 23 has a helical or helical outer geometry or outer contour. The rotor 23 is firmly connected to the drive shaft 4 with the aid of a flexible shaft or flex shaft 24. The flexible shaft 24 can be provided with a coating or passivation on the outside. For example, the flex shaft 24 can be surrounded by a rubber jacket. A chemical reaction of the fluid with the material of the flexible shaft 24 is hereby excluded. The stator 17 and the rotor 23 are interchangeable, so that the delivery volume of the metering device 2 can be changed.

The fluid can be fed to the metering device 2 via a feed opening 25 provided in the pump housing 15. The feed opening 25 can also be referred to as a product inlet. The feed opening 25 is oriented perpendicular to the central axis Mi. The fluid enters a receiving space 71 provided in the pump housing 15 from the supply opening 25. The receiving space 71 can also be referred to as the pump interior. The receiving space 71 is a bore provided in the pump housing 15 which runs in the longitudinal direction L ₁ . The flex shaft is also in the receiving space 71 24 arranged. The fluid is transported from the receiving space 71 with the aid of the rotating rotor 23 in the longitudinal direction L ₁ in the direction of the end piece 22. The dosed volume depends on the speed.

A tubular venting device 26 for venting the metering device 2 can also be provided on the pump housing 15. The ventilation device 26 is screwed into a ventilation hole 27 provided on the pump housing 15. The vent hole 27 can be arranged perpendicular to the central axis Mi. The end piece 22 and the pump housing 15 can be pinned to one another with the aid of dowel pins 28 and additionally screwed.

The metering device 2 further comprises a heating and / or cooling device 29. The heating and / or cooling device 29 can, as in FIG Fig. 5 shown, be arranged in the pump housing 15. Alternatively, the heating and / or cooling device 29 can be provided on the outside of the pump housing 15 in the form of a sleeve. The viscosity of the fluid can be changed with the aid of the heating and / or cooling device 29. For example, highly viscous fluids can be heated with the aid of the heating and / or cooling device 29 in order to reduce their viscosity, as a result of which highly viscous fluids can also be easily and reliably metered with the aid of the metering device 2. Alternatively, the heating and / or cooling device 29 can also be set up to reduce the viscosity of the fluid by cooling, so that even low-viscosity fluids can be easily and reliably metered with the aid of the metering device 2.

The heating and / or cooling device 29 can have several, for example two, heating and / or cooling elements 30, 31. The heating and / or cooling elements 30, 31 can be heating cartridges or Peltier elements, for example. The heating and / or cooling device 29 also includes a temperature sensor (not shown) and a circuit board 32. A plug 33 ( Fig. 2 ) be provided. With the help of the plug 33, the heating and / or cooling device 29 can be connected to a control device. The heating and / or cooling device 29 is optional.

The spray device 1 further comprises a spray device 34 which is set up to spray the fluid metered by the metering device 2 with the aid of a gas. In particular, the gas is pressurized. The gas can be, for example, air, carbon dioxide, nitrogen, a noble gas or any other gas. Preferably the gas is air. The spray device 34 comprises a gas housing 35, which by means of fastening means 36, of which in the Fig. 4 only one is provided with a reference number, is firmly connected to the end piece 22. The gas housing 35 can also be referred to as an air housing. The gas housing 35 is preferably made of a metal material, such as aluminum or steel, or a plastic material. The fastening means 36 can for example be hexagon socket screws. A sealing element 37, in particular an O-ring, can be arranged between the end piece 22 and the gas housing 35.

A gas supply line 38 is provided on the gas housing 35. The gas supply line 38 is designed, for example, as an L-push-in fitting. The gas supply line 38 can be screwed into a gas supply bore 39 provided on the gas housing 35. The gas supply bore 39 is arranged, for example, perpendicular to the central axis Mi. The gas supply line 38 is set up to divert the gas by 90 °. The gas supply line 38 can have a quick release fastener for connecting a gas line to the same.

The spray device 34 comprises a spray head 40 with a dosing needle 41 assigned to the dosing device 2 and a gas cap 42. The gas cap 42 can also be referred to as an air cap. The gas cap 42 is preferably made of a metal material such as aluminum or steel, or a plastic material. The metering needle 41 is preferably made of a metal material such as aluminum or steel, or a plastic material. The metering needle 41 is formed in one piece with the end piece 22 or is, as in FIG the Fig. 4 and 5 shown, screwed into the end piece 22 at the front. The gas cap 42 has a central conical opening through which the metering needle 41 is passed. Here, between the dosing needle 41 and the gas cap 42, a gap 43 encircling the dosing needle 41 is formed for the gas.

As the Fig. 2 shows, the dispensing needle 41 and the gas cap 42 can be exchanged. In this way, the spray pattern of the spray device 1 can be changed and / or the spray head 40 can be adapted to different fluids. Furthermore, vortex elements or vortex bodies for swirling the gas can be provided in the gap 43. For example, screw-shaped or spiral-shaped ribs and / or screw-shaped or spiral-shaped milled recesses, which are designed to swirl the gas, can be provided on the metering needle 41 and / or on the gas cap 42. As a result, the gas emerges from the spray head 40 with a swirl. Furthermore, the dosing needle 41 can be surface-treated on the outside and / or the gas cap 42 on the inside, for example passivated, hardened or coated. For example, a DLC coating can be used. In this way, very reactive and / or abrasive fluids can also be sprayed.

The gas cap 42 is connected to the gas housing 35 with the aid of a union nut 44. The union nut 44 can, as in the Fig. 2 shown, have a knurling 45 on the outside. This allows easy replacement of the gas cap 42. As the Fig. 2 also shows, the metering needle 41 can protrude in the longitudinal direction L ₁ by a protrusion a over the gas cap 42. Alternatively, the metering needle 41 can be flush with the gas cap 42 or stand back behind it. The protrusion a can be, for example, 0 to 1 mm. The gas is supplied to the gap 43 via a gas channel 46 which runs around the end piece 22 in an annular manner. A sealing element 68, in particular an O-ring, is provided between the gas cap 42 and the end piece 22.

The functioning of the spray device 1 is explained below. The fluid to be sprayed is supplied to the spray device 1 via the supply opening 25. The amount of fluid to be dosed is set via the speed of the rotor 23. The metering can initially take place independently of the spraying. The metered quantity of the fluid can also be influenced by different geometries of the rotor 23 and / or the stator 17. The pressurized gas is supplied via the gas supply line 38 and is evenly distributed via the gas channel 46. The gas exits via the gap 43 on the front side of the gas cap 42, the exiting gas entraining and spraying the fluid exiting from the dosing needle 41. When the gas emerges from the gas cap 42, the gas is preferably swirled in a spiral shape, as a result of which a particularly uniform spray pattern with sharp edges can be generated.

Depending on the amount of fluid metered, a different spray pattern can be achieved on a substrate to be sprayed with a constant gas flow. The fluid is metered purely volumetrically and not through a Venturi effect. As a result, a valve in the metering needle 41 can be dispensed with, since there is no negative pressure at the metering needle 41 that would tear the fluid out of the metering needle 41. Because the fluid is dosed volumetrically and independently of the gas supply, the gas can be switched on before the fluid is dosed and only switched off after the dosing has ended. This means that the amount of fluid metered in with the metering device 2 can be slowly increased to the desired metered amount when the gas is switched on and can also be continuously reduced again when the gas is still switched on. This enables the spraying process to be started up and ended like a ramp.

The gas can also be supplied in pulses. In addition, a temperature sensor can be used to determine a temperature of the fluid. A control device of the spray device 1 can readjust the metering of the fluid with the aid of the determined temperature of the fluid with access to a viscosity table stored in the control device. This can lead to metering inaccuracies prevented by thermal expansion of the fluid. The temperature sensor can be assigned to the heating and / or cooling device 29.

Because the dosing needle 41 protrudes over the gas cap 42, the fluid can also be dosed directly onto the substrate to be sprayed with the aid of the spray device 1. For example, in a first step, a dam can be applied to the substrate from the fluid to be sprayed without switching on the gas, which dam is then sprayed with the fluid in a second step with the aid of the gas. The gas preferably has a swirl when it emerges from the gas cap 42. For this purpose, the gas cap 42 can be provided on the inside and / or the metering needle 41 on the outside with a spiral contour. Furthermore, the dispensing needle 41 can be negatively charged and the substrate positively or vice versa electrically charged. This results in a better spray pattern, better edge sharpness and less blob formation. The fact that the volume flow of the fluid and the volume flow of the gas can be regulated independently of one another results in a particularly large working area for the spray device 1.

The Fig. 6 shows a further embodiment of a spray device 1. The spray device 1 comprises a first metering device 2 and a second metering device 47. The metering devices 2, 47 can be of identical construction or of different types. In particular, the metering devices 2, 47 can be constructed identically to the metering device 2 according to FIG Figs. 1 to 5 be. For example, the metering devices 2, 47 can be set up to meter different quantities of two components of a fluid volumetrically. The first metering device 2 is set up to meter a first component of the fluid volumetrically and the second metering device 47 is set up to meter a second component of the fluid. The fluid can be a two-component adhesive, for example.

Each metering device 2, 47 has a pump housing 15. The pump housings 15 can be firmly connected to one another. Alternatively, the pump housing 15 can also be made in one piece. A stator 17 and a rotatable rotor 23 are received in each pump housing 15. The rotor 23 has a helical or helical outer geometry or outer contour. The stator 17 comprises a tubular outer part 18 which is received in the pump housing 15 in a rotationally fixed manner with the aid of a dowel pin 20. The stator 17 further comprises an elastomer part 19 which is made from an elastomer material. The elastomer part 19 has a helical or helical outer geometry or outer contour. The stator 17 is clamped axially between the pump housing 15 and an end piece 22 of the respective metering device 2, 47.

The spray device 1 furthermore also comprises a common spray device 34 with a spray head 40. The spray head 40 comprises a gas housing 35 which is firmly connected, for example screwed, to the end piece 22. A gas supply line 38 for supplying a gas is provided on the gas housing 35. A first fluid channel 48 and a second fluid channel 49 are also provided in the gas housing 35. The first component of the fluid is conveyed through the first fluid channel 48 and the second component of the fluid is conveyed through the second fluid channel 49. The fluid channels 48, 49 also lead through a first connecting plate 55, which connects the spray head 40 to the pump housings 15. The fluid channels 48, 49 meet at a mixing chamber 50 in which the first component of the fluid and the second component of the fluid mix with one another. The mixing chamber 50 is provided in a second connecting plate 73. A static mixer can be provided in the mixing chamber 50. A static mixer is a built-in part that achieves the desired mixing and dispersion effects by flowing the components of the fluid through rigid mixing elements. The energy that is required for the mixing is supplied by the metering devices 2, 47. The mixing chamber 50 is particularly suitable for mixing ratios of the components of 1: 1 to 1: 5.

The spray head 40 further comprises a gas cap 42 which is fastened to the gas housing 35 with the aid of a union nut 44. The gas cap 42 has a central conical bore through which a metering needle 41 is passed. The dosing needle 41 is screwed into the connecting plate 55. The metering needle 41 can extend out over the gas cap 42 in a longitudinal direction L _{1 of} the spray device 1.

When the spray device 1 is in operation, the first component and the second component of the fluid are metered by the respective metering device 2, 47 and supplied to the mixing chamber 50. The two components mix in the mixing chamber 50 and are dosed via the dosing needle 41. The gas flows into the gas housing 35 via the gas supply line 38 and is distributed via a gas channel 46 and a gap 43 encircling the metering needle 41 in an annular manner. The gas flows in the form of a jacket around the metering needle 41 and travels with the fluid for spraying.

The Fig. 7 shows a further embodiment of a spray device 1. The spray device 1 according to FIG Fig. 7 differs from the spray device 1 according to FIG Fig. 6 essentially in that the spray device 1 according to FIG Fig. 7 has no mixing chamber 50.

The metering needle 41 is designed in several parts. The metering needle 41 comprises an inner part 51 with a central fluid channel 52 which is fluidically connected to the first fluid channel 48 and through which the first component of the fluid is conveyed. The dosing needle 41 furthermore comprises an outer part 53 which is pushed onto the inner part 51. A fluid channel 54 is provided between the inner part 51 and the outer part 53, which is fluidically connected to the second fluid channel 49 and through which the second component of the fluid is conveyed. The fluid channel 52 can be referred to as the first fluid channel of the metering needle 41 and the fluid channel 54 can be designated as the second fluid channel of the metering needle 41. The fluid channel 54 envelops the inner part 51 in the form of a jacket. This means that when the components of the fluid are being dispensed, they are not mixed but appear as two Components from the dispensing needle 41 on the front. The components are mixed in that the components are swirled and mixed with the aid of the gas during spraying.

The Fig. 8 shows a further embodiment of a spray device 1. The embodiment of the spray device 1 according to FIG Fig. 8 differs from the embodiment of the spray device 1 according to FIG Fig. 6 essentially in that a static mixer or a static mixing element 72 is provided in place of the mixing chamber 50 in the metering needle 41.

The connecting plate 55 for connecting the metering devices 2, 47 and an intermediate plate 56 are provided between the gas housing 35 and the end piece 22. The gas cap 42 is formed in one piece with the gas housing 35. A tubular gas cap extension 57 is screwed to the gas cap 42. The gas cap extension 57 can also be made in one piece with the gas cap 42. The metering needle 41 also has a tubular metering needle extension 58 in which a static mixer can be arranged. The metering needle 41 can protrude beyond the gas cap extension 57 in the longitudinal direction L ₁ . The two components are mixed with one another in the metering needle 41, in particular in the metering needle extension 58, and then sprayed.

The Fig. 9 shows a further embodiment of a spray device 1. The spray device 1 according to FIG Fig. 9 differs from the spray device 1 according to FIG Fig. 6 in that a mixing element 59 for dynamic mixing of the first component of the fluid with the second component of the fluid is arranged in the mixing chamber 50.

The mixing element 59 is non-rotatably connected to a mixing element drive shaft 60. The mixing element drive shaft 60 can be driven, for example, by means of an electric motor. By using the rotatable Mixing element 59, in particular, mixing ratios of the components of the fluid of, for example, 1: 1 up to 1: 100 can be achieved.

The Figs. 10-15 each show, in a schematic sectional view, various embodiments of a spray device 1 with different spray heads 40. The embodiments of the spray head 40 according to FIG Figs. 10-15 is for both the spray device 1 according to FIG Figs. 1 to 5 , of the Fig. 6 , of the Fig. 7 , of the Fig. 8 as well as the Fig. 9 suitable.

The Fig. 10 shows an embodiment of the spray head 40 in which the gas cap 42 has a tubular gas cap extension 61. The length of the gas cap extension 61 is arbitrary. The dosing needle 41 has a dosing needle extension 62 corresponding to the gas cap extension 61. The metering needle extension 62 can protrude beyond the gas cap extension 61 in the longitudinal direction L ₁ . The dosing needle 41 is screwed into the end piece 22. Alternatively, the metering needle 41 can be made in one piece with the end piece 22. The spray head 40 according to FIG Fig. 10 is particularly suitable for applications in which only little space is available for spraying the fluid.

The Fig. 11 shows an embodiment of the spray head 40, in which the metering needle 41 is formed in one piece with the end piece 22. Otherwise, the spray head 40 corresponds to that in FIG Figs. 1 to 5 Spray head 40 shown. The spray head 40 according to FIG Fig. 11 is particularly suitable to avoid dead spaces. For example, this is advantageous for precision with small dosing quantities.

The Fig. 12 shows an embodiment of the spray head 40 in which the metering needle 41 is designed as a disposable component or disposable. In particular, the dosing needle 41 is a disposable cannula used in medical technology. The dosing needle 41 has a connection body 63 made of a plastic material and a cannula 64, the connection body 63 in a plastic injection molding process injected onto the cannula 64 or glued to it. The connection body 63 has an inner cone 65 into which an outer cone 66 of the end piece 22 can be inserted. The inner cone 65 and the outer cone 66 form a Luer lock connection. Luer-Lock is a standardized connection system for hose systems in the medical field. As a result, the dispensing needle can be exchanged particularly easily and quickly.

A sealing element 67, in particular an O-ring, can be arranged between the inner cone 65 and the outer cone 66. The outer cone 66 is preferably formed in one piece with the end piece 22. The gas cap 42 is designed such that it encloses the connection body 63. In the gap 43 which is provided between the cannula 64 and the gas cap 42, vortex elements 69 are provided for swirling the gas. The vortex elements 69 can encircle the gas cap 42 on the inside, for example in a helical or helical manner, in order to set the gas into a swirl.

The Fig. 13 shows an embodiment of the spray head 40 in which the gas cap 42 is adjustable. The embodiment of the spray head 40 according to FIG Fig. 13 differs from the embodiment of the spray head 40 according to FIG Fig. 12 in that a length-adjustable gas pipe 70 is provided on the gas cap 42. The gas pipe 70 can be connected to the gas cap 42 with the aid of a snap-in screw connection, for example. By adjusting the gas tube 70, the exit angle of the fluid when it is sprayed can be adjusted by adjusting the protrusion of the metering needle 41 over the gas tube 70.

The Fig. 14 shows an embodiment of the spray head 40 with various vortex elements 69. The embodiment of the spray head 40 according to FIG Fig. 14 has a metering needle 41 formed in one piece with the end piece 22, which protrudes beyond the gas cap 42. Various vortex elements 69 for swirling the gas are provided in the gap 43. The vortex elements 69 can be formed in one piece or in several pieces. The vortex elements 69 can also have a twist. In particular, the vortex elements 69 are designed to redirect the gas in a helical manner.

The Fig. 15 shows an embodiment of the spray head 40 with a porous vortex element 69. The embodiment of the spray head 40 according to FIG Fig. 15 differs from the embodiment of the spray head Fig. 14 essentially in that the entire gap 43 is filled with the porous vortex element 69. The vortex element 69 can be in one piece or in several pieces. In particular, the vortex element 69 is made from a sintered ceramic or metal material. The gas flows through the vortex element 69. With the help of the vortex element 69, the gas can be swirled indefinitely, that is to say chaotically.

Although the present invention has been described on the basis of exemplary embodiments, it can be modified in many ways.

REFERENCE LIST

1

Spray device

2

Dosing device

3

Bearing housing

4th

drive shaft

5

roller bearing

6th

roller bearing

7th

Locking ring

8th

Claw coupling

9

Seal housing

10

Sealing device

11

Sealing device

12

Sealing device

13

Fasteners

14th

Sealing element

15th

Pump housing

16

Sealing element

17th

stator

18th

Outer part

19th

Elastomer part

20th

Dowel pin

21st

paragraph

22nd

End piece

23

rotor

24

Flex shaft

25th

Feed opening

26th

Ventilation device

27

Vent hole

28

Dowel pin

29

Heating and / or cooling device

30th

Heating and / or cooling element

31

Heating and / or cooling element

32

Circuit board

33

plug

34

Spraying device

35

Gas housing

36

Fasteners

37

Sealing element

38

Gas supply line

39

Gas supply hole

40

spray nozzle

41

Dispensing needle

42

Gas cap

43

gap

44

Union nut

45

Knurling

46

Gas duct

47

Dosing device

48

Fluid channel

49

Fluid channel

50

Mixing chamber

51

inner part

52

Fluid channel

53

Outer part

54

Fluid channel

55

Connecting plate

56

Intermediate plate

57

Gas cap extension

58

Dispensing needle extension

59

Mixing element

60

Mixing element drive shaft

61

Gas cap extension

62

Dosing needle extension

63

Connection body

64

Cannula

65

Inner cone

66

Outer cone

67

Sealing element

68

Sealing element

69

Vortex element

70

Gas pipe

71

Recording room

72

Mixing element

73

Connecting plate

a

Got over

L ₁

Longitudinal direction

M ₁

Central axis

Claims (11)

1. Spraying device (1) for spraying a fluid, comprising:

   a dosing mechanism (2), which is an eccentric screw pump, for volumetric dosing the fluid,

   a spraying mechanism (34) which is suited to spray the fluid that is dosed by of the dosing mechanism (2) by means of a gas, and

   a spraying head (40) with a gas cap (42) and a dosing needle (41) out of which the dosed fluid exits and which is guided through the gas cap (42), wherein the dosing needle (41) protrudes over the gas cap (42) along a longitudinal direction (L₁) of the spraying device (1), stands back behind the gas cap (42) or is flush with the gas cap (42), wherein the dosing needle (41) and/or the gas cap (42) are length adjustable, wherein the spraying head (40) comprises an swirling element (69) for swirling the gas, and wherein the swirling element (69) is made of a porous material comprising a polymer, a ceramic or a metal.
2. Spraying device according to claim 1, further comprising a heating and/or cooling mechanism (29) for heating or cooling the fluid to change the viscosity thereof.
3. Spraying device according to claim 2, wherein the heating and/or cooling mechanism (29) is arranged inside a pump housing (15) of the dosing mechanism (2).
4. Spraying device according to one of claims 1 - 3, wherein a circumferential gap (43) for the gas is provided between the gas cap (42) and the dosing needle (41).
5. Spraying device according to one of claims 1 - 4, wherein the dosing needle (41) is connected to an end piece (22) of the dosing mechanism (2) integrally or in a form-locking manner.
6. Spraying device according to one of claims 1 - 5, wherein the dosing device (2) is suited for volumetric dosing a first component of the fluid, and wherein the spraying device (1) comprises a further dosing mechanism (47), in particular an eccentric screw pump, for volumetric dosing a second component of the fluid.
7. Spraying device according to claim 6, further comprising a mixing chamber (50) for mixing the first component of the fluid with the second component of the fluid before spraying the fluid by means of the spraying mechanism (34).
8. Spraying device according to claim 7, further comprising a mixing element (59), which is arranged inside the mixing chamber (50), for dynamic mixing the first component of the fluid with the second component of the fluid.
9. Spraying device according to claim 7, further comprising a static mixer, which is arranged inside the mixing chamber (50), for static mixing the first component of the fluid with the second component of the fluid.
10. Spraying device according to one of claims 6 - 9, further comprising a spray head (40) with a dosing needle (41) which is suited for mixing the first component of the fluid with the second component of the fluid.
11. Spraying device according to claim 10, wherein the dosing needle (41) comprises a static mixing element (72).

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