DOSING SYSTEM AND METHOD FOR CONTROLLING A DOSING SYSTEM

Description

[0001] The invention relates to a metering system for metering a liquid to viscous metering substance, preferably for applying the metering substance to a substrate, and to a method for controlling such a metering system.

[0002] Dosing systems of the type mentioned above are used in a wide variety of applications to precisely dispense a medium, typically a liquid to viscous dosing agent. In so-called "microdosing technology," it is often necessary to deliver very small quantities of the medium to a target surface with high precision—that is, at the right time, in the right place, and in a precisely measured amount.

[0003] State-of-the-art dosing systems are known, for example, from DE1255009B, US2016221022A1, DE4122594A1 or EP0111850A1.

[0004] Often, dispensing is contactless, meaning there is no direct contact between the dispensing system and the target surface. This can be achieved, for example, by dispensing the material drop by drop through a nozzle of the dispensing system. The medium only comes into contact with the interior of the nozzle and a section, usually the front, of the dispensing element. The droplet size, or the amount of medium per droplet, can be precisely controlled by the design and control of the nozzle, as well as by the resulting effect. Such a contactless method is often referred to as a "jet dispensing" process. Typical examples include the dispensing of adhesive dots, solder pastes, etc., during the assembly of printed circuit boards or other electronic components, or the application of converter materials for LEDs.

[0005] To dispense the medium from the dosing system, a movable ejector element can be arranged in the nozzle of the dosing system. The ejector element can be pushed forward at a relatively high speed inside the nozzle towards a nozzle opening or outlet, thereby ejecting a droplet of the medium, which is then retracted. This means that in the dosing systems mentioned above, as well as in the dosing system according to the invention, the metering substance is ejected from the nozzle by the ejector element itself. To eject the medium from the nozzle, the ejector element comes into contact with the metering substance to be dispensed and, due to a movement of the ejector element and / or the nozzle, "pushes" or "pushes" the metering substance out of the nozzle of the dosing system. Thus, the metering substance is "actively" ejected from the nozzle by means of the movable ejector element.This distinguishes such dosing systems, including the dosing system according to the invention, from other dispenser systems in which movement of a closure element merely leads to the opening of the nozzle, with the pressurized metering substance then exiting the nozzle automatically. This is the case, for example, with fuel injectors in internal combustion engines.

[0006] The ejector element can typically be moved into a closed position by firmly engaging a sealing seat in the nozzle opening and remaining there temporarily. With more viscous metering media, it may also be sufficient for the ejector element to simply remain in the retracted position, i.e., away from the sealing seat, without any drop of the medium escaping.

[0007] The movement of the dispensing element required to eject the metering material is typically achieved using an actuator unit within the metering system. Such an actuator unit can be implemented in various ways, for example, using a pneumatically or hydraulically driven actuator. Alternatively, piezoelectric and / or electromagnetically driven actuators are also used. Compared to the aforementioned actuator principles, an actuator unit with a pneumatic or hydraulic actuator is characterized by a comparatively simple design, which also reduces the overall complexity of the metering system. Therefore, pneumatic or hydraulic actuators represent a cost-effective solution for operating metering systems, particularly when processing easily metered materials.

[0008] Pneumatic and hydraulic actuators can be implemented in various ways. For example, dosing systems are known where the actuator is implemented using a pneumatic or hydraulic cylinder. Since such systems experience comparatively high wear in the area of ​​the cylinder's frictional seals, pneumatic and hydraulic actuators implemented using a bellows pressurized with a pressure medium are increasingly being used.

[0009] Another preferred alternative is to design the pneumatic or hydraulic actuator using a diaphragm that can be pressurized with a pressure medium. This variant offers the advantage that, on the one hand, frictional seals, such as those found in pneumatic or hydraulic cylinders, can be omitted. On the other hand, the design and manufacturing effort can be reduced compared to "bellows-operated" actuators.

[0010] Furthermore, diaphragm-operated pneumatic or hydraulic actuators can be operated at a higher cycle frequency than is usually the case with bellows-operated or cylinder-operated actuators. Therefore, diaphragm-operated pneumatic or hydraulic actuators are particularly suitable for highly precise dosing requirements.

[0011] To transmit the force generated by a "diaphragm-operated" pneumatic or hydraulic actuator to the dispensing element of the metering system, a deflectable diaphragm of the actuator is rigidly connected to the dispensing element in known metering systems. For example, the dispensing element can be permanently welded, riveted, screwed, soldered, or glued to the diaphragm. It is also possible for the dispensing element to completely penetrate the diaphragm and be firmly screwed to it on at least one side surface, or to be rigidly connected to the diaphragm by means of a retaining ring or a pin. While the aforementioned methods achieve a rigid coupling between the dispensing element and the diaphragm, they do not guarantee a secure connection.

[0012] However, this design also leads to an increase in the overall mass of the diaphragm that needs to be moved, due to the required connection mechanism. To deflect or move the diaphragm as desired, its diameter can be increased to enhance the acceleration force. However, increasing the diaphragm diameter also necessitates an increase in the volume of the actuator chamber of the pneumatic or hydraulic actuator, which is filled with the pressurized medium to deflect the diaphragm. This, in turn, makes the filling and emptying process of the actuator chamber more time-consuming, unnecessarily slowing down the cycle time of the dosing system.

[0013] On the other hand, in a conventional pneumatic or hydraulic actuator, the diaphragm can be significantly weakened due to the rigid connection of the ejector element to the diaphragm. The connection point between the ejector element and the diaphragm, in particular, can develop a weak point in the diaphragm, similar to a predetermined breaking point, which can be problematic, especially during continuous operation of the dosing system. This can considerably shorten the service life of the pneumatic actuator, leading to increased maintenance and thus higher operating costs for the dosing system.

[0014] It is therefore an object of the present invention to provide a dosing system with an actuator that reduces and preferably avoids the aforementioned disadvantages. Furthermore, it is an object to provide a method for controlling such a dosing system.

[0015] This problem is solved by a dosing system according to claim 1 and by a method for controlling such a dosing system according to claim 13.

[0016] A metering system according to the invention for metering a liquid to viscous metering agent, in particular for preferably contactless application of a metering agent to a substrate, has a housing, optionally comprising several parts, wherein the housing includes at least one nozzle and a feed channel for metering agent. The metering agent to be metered enters a nozzle chamber of this nozzle via the feed channel of the metering system.

[0017] The metering system further comprises an ejection element, which is movably arranged within the housing, and an actuator unit coupled to or cooperating with the ejection element for the dispensing of the metering substance. As a result of this coupling, the actuator unit interacts with the ejection element in such a way that the metering substance is dispensed from the nozzle of the metering system by means of the ejection element. Thus, as explained above in the introductory part of the application, such an ejection element "actively" ejects the metering substance. Preferably, the metering system can be implemented in the manner of a jet valve, whereby the metering substance dispensing can occur without contact, as explained above.

[0018] According to the invention, the actuator unit comprises at least one actuator with a diaphragm, preferably disc-shaped as explained later, which can also be referred to as an "actuating diaphragm". Particularly preferably, the actuator comprises only a single diaphragm.

[0019] The actuator unit can also include further components required for moving the ejector element in the metering system, as will be explained later. In contrast, those components of the metering system that come into contact with the metering material, e.g., the ejector element, can preferably be combined in a fluidic unit of the metering system, as will also be explained later.

[0020] The actuator's diaphragm, in particular a side surface of the diaphragm facing away from the ejection element, can be pressurized by at least one pressure medium such that the ejection element is moved or deflected in an ejection direction to expel the metering substance from the nozzle. Gaseous and / or liquid substances are used as the pressure medium. When the diaphragm is pressurized, the pressure medium, especially when in motion, strikes directly the side surface (top surface) of the diaphragm facing away from the ejection element – ​​as the name "pressurization" suggests. This means that the diaphragm is deflected directly by the pressure medium itself to expel the metering substance from the nozzle. For this purpose, the ejection element is moved by the diaphragm towards an outlet opening of the nozzle. The movement can be such that, at the end of the ejection movement, a tip of the ejection element rests directly against a sealing surface of the nozzle.Alternatively, the ejection movement can be stopped beforehand, leaving a gap between the tip of the ejection element and the sealing seat of the nozzle.

[0021] According to the invention, the ejection element is designed separately from the membrane, i.e., it is a component separate from the membrane itself. Preferably, the ejection element is formed in one piece. To couple it to the actuator unit, the ejection element is pressed into an operating position during operation of the metering system by means of a force acting directly on the ejection element, through contact pressure against a side surface of the membrane facing towards the ejection element. The side surface of the membrane intended for coupling thus faces away from the side surface of the membrane that is exposed to the pressure medium. The two side surfaces of the membrane correspond, with regard to their design, to a base surface of the membrane, as will be explained later.

[0022] The side surface facing the ejection element or nozzle is typically oriented "downwards" when the metering system is used as intended (since the metering system is usually arranged in operation so that the metering agent is dispensed downwards from the nozzle), and is therefore referred to below, without limitation, as the "underside" of the membrane. The side surface of the membrane opposite the underside, which can be pressurized, is accordingly referred to as the "topside" of the membrane.

[0023] For coupling, the force between the ejection element, e.g. a plunger, and the actuator unit is exerted only on the ejection element itself, i.e. not directly on the membrane but only indirectly via the ejection element, meaning that at least part of the force can be transferred from the ejection element to the membrane due to the coupling.

[0024] According to the invention, as mentioned, the ejection element is designed separately, i.e., it is not rigidly or permanently connected to the membrane. In particular, no positive fit or material bond between the respective components is required to couple the ejection element to the actuator unit or the actuator membrane. The coupling is based more on the principle of frictional connection. By means of the force acting on the ejection element, the ejection element can be continuously held in operative contact with the side surface of the membrane facing the direction of the ejection element during operation of the dosing system. Only if the force acting on the ejection element for coupling is absent or falls below a certain value do the ejection element and the membrane again form two uncoupled, independent components.

[0025] The ejector element is therefore held in place on the membrane in a way that is "penetration-free" and "damage-free." This means that the ejector element is not, for example, screwed, welded, glued, etc., to the membrane. In particular, the coupling process does not involve any significant alteration to the surface properties of either the underside or the top of the membrane.

[0026] Since the ejection element and the diaphragm are designed as independent, unconnected components, which are only combined into a functional unit (the metering system) by means of the force acting on the ejection element, the metering system according to the invention advantageously achieves that only very small masses need to be moved by the actuator of the actuator unit during operation. This allows the overall weight of the actuating diaphragm to be kept as low as possible, and the volume of the actuator chamber for actuating the diaphragm can also be kept small. This design allows the filling and emptying process of the actuator chamber to be accelerated, so that the actuator achieves very high dynamic values. Advantageously, the metering system is thus also suitable for metering highly viscous substances despite its comparatively simple design.

[0027] Furthermore, the dosing system according to the invention advantageously avoids, almost entirely, the design-related weakening of the membrane, which is frequently the case in conventional dosing systems in the area of ​​the fixed connection between the membrane and the ejection element. Moreover, the actuator can also dispense with frictional seals, such as those required in pneumatic or hydraulic cylinders. Therefore, the dosing system according to the invention advantageously extends the uninterrupted operating time of the actuator and thus also of the entire dosing system, while simultaneously enabling very high cycle frequencies for the dispensing of the metering material.

[0028] In a method according to the invention for controlling a metering system for dispensing a liquid to viscous metering agent, in particular for preferably contactless application of the metering agent to a substrate, the metering system has a housing, optionally comprising several parts, wherein the housing includes at least one nozzle and a feed channel for the metering agent. As mentioned above, the housing has an ejection element which is movably arranged in the housing, as well as an actuator unit coupled to or cooperating with the ejection element for dispensing the metering agent.

[0029] According to the invention, an actuating diaphragm of an actuator of the actuator unit is pressurized with a pressure medium to move or deflect the ejection element in an ejection direction for expelling the metering substance from the nozzle. Gaseous and / or liquid substances are used as the pressure medium. Preferably, a side surface (also called the "top") of the diaphragm facing away from the ejection element is pressurized with the pressure medium to move the ejection element towards a nozzle. A force is exerted on the ejection element itself to couple it to the actuator unit. By means of the force acting on the ejection element, the ejection element is pressed against a side surface (also called the "bottom") of the diaphragm facing towards the ejection element by means of a contact pressure.The force can be applied to the ejection element in such a way that the ejection element is continuously kept in effective contact with the membrane during operation of the dosing system, in particular with the side surface of the membrane facing the direction of the ejection element.

[0030] Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, wherein the independent claims of a claim category may also be further developed analogously to the dependent claims and embodiments of another claim category, and in particular individual features of different embodiments or variants may be combined to form new embodiments or variants.

[0031] Preferably, the metering system is designed such that the force acting on the ejector element, e.g., a plunger, for coupling is directed opposite to the ejection direction, i.e., the direction of an ejection movement, of the ejector element. The ejection direction corresponds to the (linear) movement of the ejector element for dispensing the metering material from the nozzle. The ejection direction is therefore directed from the coupling point (between the ejector element and the diaphragm) towards the nozzle of the metering system. Preferably, a force can thus be exerted on the ejector element for coupling such that one (effective) direction of the force points away from the nozzle and is essentially perpendicular to a base surface of the actuator's diaphragm.

[0032] A movement of the ejector element, also known as the "plunger," in the opposite direction—that is, a movement away from the nozzle—is called a retraction movement. Accordingly, the retraction movement occurs in a retraction direction of the ejector element, as explained below.

[0033] Particularly preferably, the metering system can be designed such that the ejector element, for coupling to the actuator unit, is permanently pressed against the underside of the diaphragm facing the ejector element during operation by means of a force applied by at least one spring and / or pressure arrangement. The force exerted by the spring and / or pressure arrangement is particularly large enough to keep the ejector element in continuous direct contact with the underside of the diaphragm, even during a retraction movement of the ejector element, i.e., when the ejector element is moved away from the nozzle towards the actuator unit after dispensing the metering material.

[0034] The spring and / or pressure assembly can simply consist of several springs or other resilient components. In the simplest and therefore often preferred case, it can consist of a single resilient component, e.g., a single spring, particularly a coil spring. For the sake of simplicity (without limiting generality), the spring assembly will henceforth also be referred to as a spring or "return spring." Alternatively or additionally, the spring and / or pressure assembly can also include pressure elements of a different form, such as pneumatic pressure cylinders, a different diaphragm device, or the like.

[0035] Preferably, the return spring can be designed to move the ejection element into a rest position within a specific time interval, particularly as soon as the diaphragm is no longer pressurized. The rest position of the ejection element is characterized by the fact that the maximum possible distance (during operation) between a tip of the ejection element and the nozzle is achieved; that is, the spring pushes the ejection element upwards as far as possible towards the actuator unit. Preferably, the ejection element also rests directly against the underside of the diaphragm in a rest position.

[0036] Preferably, the return spring can also exert a "restoring effect" on the diaphragm. While the diaphragm can preferably be designed to return to a rest position independently within a certain time interval as soon as it is no longer pressurized by the medium (i.e., the diaphragm can be elastic), the forces exerted by the return spring can at least support the elastic properties of the diaphragm, i.e., the spring can facilitate the diaphragm's return to its rest position.

[0037] Preferably, the return spring can therefore be designed to transmit a force to the diaphragm (indirectly via the ejection element), wherein the force preferably acts away from the nozzle towards the actuator unit and can preferably be determined such that the return spring pushes the diaphragm (indirectly) upwards by a certain amount and / or even brings it into a rest position. The diaphragm is in its rest position when it is not currently pressurized with a pressure medium and / or is not deflected towards the nozzle. Preferably, the diaphragm or diaphragm wall can extend essentially in one plane in the rest position, i.e., it has a substantially straight or linear cross-section. However, it is also possible that the diaphragm is curved upwards, at least partially, in the rest position, i.e., towards the actuator unit, for example, by being pushed upwards by the ejection element.

[0038] Preferably, the force on the ejector element for coupling can act, as mentioned, such that the ejector element rests directly against the underside of the diaphragm even in its rest position, while maintaining the previously mentioned essentially linear cross-sectional shape of the diaphragm. Alternatively, the spring can also be dimensioned and / or designed such that the ejector element (in a rest position) pushes or deflects the diaphragm (in a rest position) upwards towards the actuator unit by a certain amount. Preferably, the diaphragm can rest directly against a base body of the actuator, at least partially, in its rest position.

[0039] The actuator's diaphragm can preferably be disc-shaped. A disc is generally understood to be a geometric body or structure whose base area is many times greater than its thickness. The base area corresponds to the largest surface of the diaphragm. Thus, the base area corresponds on the one hand to the side of the diaphragm facing the plunger and on the other hand to the (opposite) side of the diaphragm that is subjected to pressure.

[0040] The thickness of the diaphragm corresponds to its extent perpendicular to the base, where the thickness is determined, for example, by a section perpendicular to the base (cross-section). Preferably, the diaphragm can have a constant, uniform thickness across its entire extent. However, it is also possible for an edge region of the diaphragm (in cross-section) to be thinner than a central region. This increases the stiffness of the diaphragm in the central region, for example, where the diaphragm's ejector element rests, with the diaphragm being deflected predominantly at the edge when subjected to a pressure medium. This increases the effective area of ​​the diaphragm and thus the force generated by the diaphragm. Alternatively or additionally, the diaphragm could have a surround in an edge region, as is the case, for example, with loudspeakers.

[0041] It is also conceivable that the membrane has a corrugated cross-section, e.g., like a corrugated sheet, whereby the spring rate and thus the restoring force of the membrane is reduced compared to a "non-corrugated" or flat membrane. For the sake of simplicity, the following discussion assumes a flat membrane of uniform thickness, which has a predominantly straight cross-section in its resting position, without any further restrictions.

[0042] Regardless of the specific design of the membrane, its thickness can be at least 10 µm, preferably at least 50 µm, and preferably at least 150 µm. The maximum thickness of the membrane can be at most 1000 µm, preferably at most 300 µm, and preferably at most 200 µm.

[0043] Preferably, the base of the membrane can be essentially round or circular. However, it can also be elliptical, rectangular, or any other shape. It is preferred that the membrane be designed as a flat or thin, i.e., "plate-like," structure. Particularly preferably, the membrane is free of cavities, meaning that there are no cavities inside the membrane, such as liquid-filled and / or gas-filled chambers. This distinguishes a membrane significantly from a bellows, such as a metal bellows, due to its construction. Unlike a membrane, a bellows comprises a more or less elastic, accordion-like folding tube and an interior space sealed from its surroundings, such as a gas-fillable cavity.

[0044] The membrane is preferably made entirely of metal. Preferably, the membrane may comprise a mixture of different metals or an alloy. For example, the membrane may be made of stainless steel (spring steel). Alternatively, the membrane may comprise, for example, a copper-beryllium alloy. Elastomers or plastics are also conceivable as membrane materials. Depending on the requirements, a multilayer membrane may also be used, with the individual layers being made of the same or different materials. For example, a membrane may have a special coating on the top and / or bottom surface. Preferably, the membrane is designed to have high vibration resistance and a certain degree of elasticity to allow for the desired deflection of the membrane.Bevorzugt ist die Membran so beschaffen, dass sie ein "aktives" Ausdehnungselement gegenüber einem starren Grundkörper des Aktors darstellt, wie nachfolgend erläutert wird.

[0045] Preferably, the membrane, and in particular an edge region of the membrane, is completely and tightly coupled to a rigid, optionally multi-part, actuator body. This creates an actuator chamber between the actuator body and the membrane, especially its upper surface, which can be pressurized with a pressure medium. To form the actuator chamber, the membrane can be welded or soldered to the actuator body, for example. Alternatively, the membrane can also be clamped to the actuator body, for example, by being sealed and clamped between two housing parts of the actuator body.

[0046] The actuator chamber is therefore located within the actuator itself. Preferably, the actuator chamber can be gas-tight and / or liquid-tight from the actuator's environment. Preferably, the actuator body includes an opening (hereinafter referred to as a "bore" without loss of generality) on a side opposite the diaphragm, which leads from the actuator chamber to the outside of the actuator chamber to allow control of the actuator. Preferably, a control valve of the actuator unit can be located directly adjacent to the bore to control the flow of the pressure medium through the bore, i.e., to "open" and "close" the actuator chamber, as explained below.

[0047] Advantageously, the actuator is implemented using only one diaphragm, meaning that only this single diaphragm needs to be sealed and coupled to the actuator body. This simplifies the design of the dosing system, especially compared to bellows-operated systems. In the latter, the bellows or hose typically needs to be sealed at two opposite ends.

[0048] To control the actuator, a pressure medium can be supplied to the actuator chamber, e.g., via the previously mentioned bore. Preferably, an overpressure can be generated in the actuator chamber to deflect the diaphragm downwards from a rest position, i.e., towards the nozzle of the metering system. The level of the overpressure can be predetermined and can depend, for example, on the properties (e.g., the viscosity) of the metering medium. For example, the overpressure could be in the range of approximately 5 bar to 8 bar. However, significantly higher pressures are also possible, as will be explained later. The diaphragm can also be referred to as a pressure diaphragm, which is designed to transmit a force to the plunger and simultaneously seal the actuator chamber. Furthermore, the actuator chamber can also be emptied again via the same bore.The overpressure in the actuator chamber is reduced, whereby the membrane, due to its elasticity and / or by means of the return spring, is brought back into a preferably vertical rest position.

[0049] The actuator chamber can, in principle, be filled with any flowing fluid; that is, (compressed) gaseous and / or liquid substances can be used as the pressure medium. Preferably, a compressed gaseous fluid can be used as the pressure medium, e.g., a single gas or a gas mixture, such as air. It is assumed hereafter that the actuator is operated with compressed ambient air, since this is readily available in most systems with metering systems anyway. Therefore, the actuator is also referred to synonymously as a pneumatic actuator within the scope of this application. However, the invention is not limited to this but is defined by the appended claims.

[0050] To optimally control the actuator for metering, the aforementioned bore of the actuator chamber is preferably directly adjacent to the control valve of the actuator unit, in particular in a gas- and / or liquid-tight manner. The control valve is preferably configured to control and / or regulate the supply of pressurized medium to and discharge of pressurized medium from the actuator chamber. For this purpose, the control valve is preferably coupled to a control and / or regulation unit of the metering system. The control valve can, for example, be implemented using a solenoid valve. Preferably, the control valve can be implemented using a 3 / 2-way valve (e.g., normally open). Alternatively, the control valve could, for example, also comprise two 2 / 2-way valves. The control valve can also be referred to as a pneumatic valve.

[0051] Preferably, the control valve can be arranged in the actuator unit such that a first connection (working port) of the control valve (gas-tight) interacts with the bore of the actuator chamber, allowing the actuator chamber to be filled with and emptied of pressurized medium via this connection. Preferably, a second connection (compressed air port) of the control valve is functionally coupled to a compressed air supply of the metering system. A third connection (vent port) of the control valve can be coupled to a venting area of ​​the actuator unit, as will be explained later. Preferably, depending on the control valve's activation, the working port can interact with either the compressed air port or the vent port. To supply the actuator chamber with a sufficient quantity of pressurized medium during operation via the control valve, the housing of the metering system can incorporate an internal pressure reservoir.The system comprises a pressure tank for the pressurized pressure medium. Preferably, this pressure tank can be separated or insulated from other housing areas of the metering system. The pressure tank can include at least one inlet opening for the pressure medium into the pressure tank and one outlet opening for the pressure medium out of the pressure tank, particularly for the supply line to the control valve. Preferably, the pressure tank can be dimensioned to hold a sufficient quantity of pressure medium for at least 250, preferably at least 2000, and particularly preferably at least 10,000 diaphragm deflections. Preferably, the pressure of the pressure medium in the pressure reservoir can be at least 2 bar, more preferably at least 3 bar, and more preferably at least 5 bar. Preferably, the pressure should be at most 1000 bar, more preferably at most 20 bar, and most preferably at most 10 bar.

[0052] The pressure tank can be connected to an external compressed air supply for the dosing system. For example, a compressed pressure medium can be fed into the pressure reservoir via the feed opening, e.g., by connecting an external pressure medium supply to a corresponding coupling point on the housing of the dosing system. Preferably, a preset pressure (target pressure) can be maintained essentially constant in the pressure tank, even during operation of the dosing system.

[0053] For the most efficient operation of the pneumatic actuator, the pressure reservoir can be located inside the housing, directly adjacent to the actuator unit's control valve. Preferably, the pressure reservoir is positioned within the dosing system housing such that the pressurized medium can flow directly from the pressure tank into the actuator chamber via the shortest possible path. In other words, the pressure reservoir can be located as close as possible to the point of demand. Preferably, the discharge port of the pressure tank is directly (gas-tightly) connected to the compressed air inlet of the control valve.

[0054] Advantageously, the pressure reservoir thus acts as an internal "pressure medium buffer" within the dosing system, dampening pulsed consumption of pressure medium, especially at high dosing frequencies. Dosing systems with pneumatic actuators typically use an external pressure tank for this purpose. However, pressure losses in the pressure medium can occur even on the way from the external pressure tank to the actuator, resulting in the actuator chamber not being filled with the desired, and especially constant, pressure. Furthermore, the pressure at which the actuator is filled—also referred to as the actuator's filling pressure—can significantly influence the dosing accuracy of the dosing system and may even negatively affect it, as will be explained later.

[0055] In contrast, the described dosing system has its pressure medium buffer located in close proximity to the actuator, eliminating the need for a line between the pressure tank and the actuator housing. This ensures that the actuator housing is always filled with a pressure medium at a specific target pressure, even at very high cycle frequencies. As mentioned, this has a positive effect on dosing accuracy.

[0056] On the other hand, this design also allows for significantly higher cycle frequencies than conventional dosing systems with pneumatic actuators, since no line losses occur between the pressure tank and the pneumatic actuator, even at very high cycle frequencies. While dosing frequencies of up to approximately 330 Hz have been possible so far, the described design enables dosing frequencies of 600 Hz and more. In principle, the internal "pressure medium buffer" also allows for even higher cycle frequencies (>700 Hz), although in this respect, the control valve becomes the speed-limiting factor due to heat generation.

[0057] To further improve the beneficial effect of the internal "printing medium buffer", the dosing system may preferably include, in addition to the internal pressure tank, another, possibly larger, external pressure tank, e.g. in the external printing medium feed.

[0058] The concept of an internal pressure tank can be advantageously enhanced by arranging at least one pressure sensor within the pressure reservoir to measure the pressure of the pressure medium. For example, the pressure sensor could be integrated into a wall of the pressure tank.

[0059] Preferably, the pressure sensor is arranged as close as possible to the pneumatic actuator. The pressure sensor can preferably be coupled to the control unit of the dosing system for the transmission of measurement data. The control unit can either be designed as a direct component of a dosing system or be implemented separately from the dosing system. A third possibility is that the control unit is designed separately and assigned to several dosing systems simultaneously in order to control them independently.

[0060] The term "control" is used synonymously with "control" and / or "regulation" in the following. This means that even when referring to "control," the control process can encompass at least one regulation process. In regulation, a controlled variable (actual value) is generally continuously measured and compared to a reference variable (setpoint). Regulation typically occurs in such a way that the controlled variable is adjusted to match the reference variable. This means that the controlled variable (actual value) continuously influences itself within the control loop.

[0061] To control the pressure in the pressure reservoir, the dosing system can include at least one controllable pressure regulator. Preferably, the pressure regulator is configured to control and / or regulate the pressure of the pressure medium in the pressure reservoir as a function of an input parameter, preferably by controlling and / or regulating the pressure of a pressure medium flowing into the housing of the dosing system or into the reservoir.

[0062] The pressure in the pressure reservoir, i.e., the pressure upstream of the control valve, is also referred to as the actuator's supply pressure. The supply pressure determines the maximum pressure at which the actuator chamber can be filled, meaning the maximum pressure the pressure medium can have when flowing into the actuator chamber. In the simplest case, the supply pressure can also correspond to the actuator's filling pressure. The actuator's filling pressure corresponds to the pressure that the pressure medium actually has in the (filled) actuator chamber, e.g., during diaphragm deflection. Depending on the design of the metering system, however, it is also possible for the actuator's filling pressure to deviate from the supply pressure, as will be explained later. Therefore, the pressure regulator can preferably also be designed to control and / or regulate the pressure at which the actuator is filled with pressure medium (actuator filling pressure) as a function of an input parameter.

[0063] The pressure regulator can be operated mechanically or manually. Preferably, an input parameter can be transmitted to an operator of the dosing system, who then adjusts the pressure regulator so that a target pressure is reached in the pressure reservoir.

[0064] Preferably, an electronic pressure regulator may also be used. Particularly preferably, the pressure regulator can be controlled by the control unit of the dosing system, especially taking input parameters into account. Regardless of the specific design (mechanical and / or electronic), the pressure regulator may preferably be arranged on the housing of the dosing system and / or in an external pressure medium supply line.

[0065] Preferably, the (mechanical or electronic) pressure regulator can be controlled or regulated as a function of an input parameter in such a way that a certain, e.g. a constant, speed of the ejection element (piston speed) is achieved during the ejection movement in the operation of the dosing system.

[0066] An input parameter for the control system can be, for example, the current pressure in the pressure reservoir. Preferably, the pressure sensor's measurement data (actual values) can be continuously compared with a predefined setpoint value by the control unit during operation. The pressure regulator is then preferably controlled such that a setpoint pressure is continuously maintained in the internal pressure tank or a constant plunger speed is achieved during operation.

[0067] Advantageously, the dosing accuracy of the dosing system can be further improved by means of the pressure sensor and the internal pressure reservoir in conjunction with the control unit. A crucial factor for the amount of metering material dispensed per plunger stroke is the plunger velocity, particularly when it impacts the nozzle or its sealing seat. Preferably, the plunger velocity (during the ejection movement) can therefore be set to a target value, which may be constant, during operation. The plunger velocity depends significantly on the actuator filling pressure.

[0068] In this respect, a higher actuator filling pressure results in a greater acceleration force on the diaphragm, leading to a higher plunger speed. Conversely, a lower actuator filling pressure results in a slower plunger speed during the ejection process. Therefore, pressure fluctuations during the filling process of the actuator chamber can negatively impact dosing accuracy. Advantageously, by controlling and / or regulating the pressure in the pressure tank and / or the actuator filling pressure, the plunger speed can be set to a predefined value and kept constant during operation, for example, to further increase dosing accuracy even under very dynamic and / or high dosing demands. For instance, pressure fluctuations in the supply line could be compensated for using this control system.

[0069] To further improve dosing accuracy, the dosing system can include at least one sensor for measuring the velocity of the ejector's movement. Preferably, the velocity sensor can be located in a region of the rigid actuator body. More preferably, the sensor can be located in a region of the actuator body opposite the top surface of the membrane, i.e., "above" the membrane. Preferably, the velocity sensor and the ejector, e.g., a plunger head, can be arranged on an imaginary (vertical) line. Preferably, the velocity sensor is coupled to the control unit.

[0070] The velocity sensor is preferably configured to detect the velocity of the ejector element during the entire ejection and / or retraction movement of the ejector element. For example, the velocity sensor can be implemented using a position sensor (stroke sensor) configured to detect a plunger position as a function of time. Preferably, the velocity sensor can be implemented using a Hall sensor. Preferably, a "head region" of the ejector element in contact with the diaphragm can then include a magnet.

[0071] Alternatively, the speed sensor could include a capacitive distance sensor. For example, the distance sensor and the diaphragm (as a movable counter surface) could form an electrical capacitor, e.g., by designing the diaphragm like a capacitor plate.

[0072] Advantageously, the measured values ​​from the velocity sensor can be supplied to the control unit as an additional input parameter. These velocity measurements can be used alternatively or additionally to the measured values ​​from the pressure sensor to control and / or regulate the actuator's supply pressure and / or its filling pressure, in order to achieve, for example, a constant plunger velocity during operation, particularly when impacting the nozzle's sealing seat. This control system can, for instance, compensate for fluctuations in the properties of the metering fluid.

[0073] Another alternative or additional way to adjust the plunger speed is to control the actuator's filling process by means of a throttling device. Preferably, the metering system, e.g., the control valve, can include at least one controllable throttling device. The throttling device can be configured to control and / or regulate the pressure of the pressure medium in the actuator, particularly in the actuator chamber, depending on an input parameter. Preferably, the throttling device can be configured to dynamically control and / or regulate the pressure in the actuator, particularly depending on an input parameter. Preferably, the throttling device can be controlled such that the pressure in the actuator during a (first) ejection stroke differs from the pressure in the actuator during a (second) subsequent ejection stroke; that is, the pressure in the actuator can be changed "from pulse to pulse."

[0074] Preferably, the throttling device can comprise at least one controllable proportional valve and / or one controllable pressure regulator. The throttling device can be configured to control and / or regulate the volumetric flow rate of the pressurized medium flowing into the actuator chamber. For example, the throttle can be located in the working port of the control valve and / or in the bore of the actuator body. Preferably, depending on the control signal, the flow cross-section can be reduced or increased, e.g., to achieve a maximum possible flow cross-section. Alternatively, a controllable proportional valve could be located in the compressed air port and / or the vent port of the control valve.

[0075] Alternatively or additionally, the throttle can be designed or controlled in such a way that the flow of pressure medium into the actuator chamber is completely interrupted at a specific time. Preferably, the proportional valve in the working port could be (completely) closed as soon as a certain pressure is present in the actuator chamber during filling. Preferably, the throttle can be controlled so that a certain pressure, e.g., a maximum permissible pressure, is not exceeded in the actuator chamber during operation. This may, under certain circumstances, result in the pressure of the filled actuator (for deflecting the diaphragm) being lower than the supply pressure. The metering system can include a pressure sensor to measure the pressure in the actuator chamber.

[0076] The throttling device can be implemented using a mechanical or manual throttle. Preferably, at least one input parameter can be transmitted to an operator of the metering system, who then adjusts the throttle (which could also be called an expansion valve) so that a specific (target) flow rate through the throttle, and thus a desired plunger velocity during the plunger's ejection movement, is achieved.

[0077] Preferably, the throttling device can be implemented using an electronic throttle, e.g., a proportional valve. Preferably, the throttle can be controlled by the control unit, depending on an input parameter, e.g., an actual plunger velocity, such that a specific volume flow rate or a desired pressure is achieved in the actuator chamber. Alternatively or additionally, the throttling device can be controlled so that a specific pressure in the actuator, particularly during filling, is not exceeded. Most preferably, the throttling device can be controlled, depending on at least one input parameter, so that a predefinable plunger velocity, e.g., constant, is achieved during the ejection and / or retraction movement.

[0078] Advantageously, the controllable throttle device allows the plunger speed during the ejection movement to be set to a constant value during operation. The controllable throttle device thus represents a second alternative or additional option for maintaining a constant plunger speed during operation and thereby further improving dosing accuracy.

[0079] To further improve the dosing result, the dosing system can be configured to set a specific speed profile of the ejector element during each ejection and / or retraction movement. Dynamic control of the ejector element's speed is also known as edge control. Preferably, the dosing system, and more preferably the control valve, can include at least one throttling device configured to control and / or regulate a pressure profile during the actuator's filling with pressure medium and / or during its emptying or venting. Preferably, the control and / or regulation can be performed based on at least one input parameter.

[0080] Preferably, the throttling device can be configured to adjust the flow rate of the fluid by locally (variably) narrowing a flow cross-section, thus enabling the filling process of the actuator chamber to be controlled over time. This means that the pressure increase in the actuator chamber can be controlled over time by means of the throttle (time-based control of the pressure curve). Preferably, the throttle can be configured to dynamically control or regulate the flow rate during each ejection movement and / or during each retraction movement of the ejection element.

[0081] Preferably, the throttling device can be controlled such that the pressure increase in the actuator chamber is dynamic or variable, i.e., the pressure in the actuator chamber does not increase constantly or linearly. The pressure profile here refers to the pressure in the actuator, particularly in the actuator chamber, as a function of time (during filling or venting). Preferably, the throttling device can be controlled such that the velocity of the plunger varies during the ejection movement, i.e., that the plunger has two or more different velocities or is accelerated to two or more different velocities during a single ejection movement. Preferably, the velocity of the plunger can be controlled and / or regulated throughout the entire plunger movement, i.e., from the rest position until impact with the nozzle.

[0082] The throttling device can be implemented using a controllable proportional valve. For the highest possible resolution control of the plunger's velocity profile during the ejection process, at least one actuator, e.g., a piezoelectric actuator with variable flow, can preferably be used. Preferably, the electronically controllable piezoelectric actuator is part of the throttling device and can be controlled by the control unit to regulate the volumetric flow rate of the pressure medium flowing into and / or out of the actuator with virtually no delay. For example, the control valve could be designed such that the flow cross-section of the control valve's working port (e.g., a 3 / 2-way valve or two 2 / 2-way valves) can be controlled (changed) in essentially real time by means of the actuator during the flow of pressure medium into and / or out of the actuator.

[0083] Alternatively, the control valve can also comprise two separately controllable proportional valves instead of a 3 / 2-way valve, thus simultaneously implementing a throttling device. In this case, a first proportional valve could be used for (time-controlled) filling of the actuator chamber and a second proportional valve for (time-controlled) venting of the actuator chamber, with the two proportional valves utilizing the same or different bores in the actuator chamber. This allows the pressure profile during filling and venting to be controlled and regulated separately.

[0084] An input parameter on which the control depends can be, for example, a measurement signal from the speed sensor.

[0085] Preferably, a predefinable velocity profile of the plunger can also serve as an input parameter. This profile is generated, for example, based on the properties of the metering medium and / or the metering requirement and can be stored in the control unit. Preferably, the control unit can then adjust the pressure during the actuator filling process based on the actual velocity of the plunger so that a desired velocity profile is achieved during the ejection process. For example, the throttling device could be controlled so that the plunger, starting from its rest position, is initially accelerated to a very high velocity by means of the diaphragm (strong inflow of pressure medium into the actuator, i.e., rapid pressure increase in the actuator chamber) in order to achieve shearing of the metering medium. In a second phase of the ejection movement, the plunger velocity could then be reduced (reduced inflow of pressure medium into the actuator, i.e.,slower pressure increase in the actuator chamber) to achieve clean ejection of the metering material from the nozzle.

[0086] Advantageously, the dosing system, particularly by means of a throttle device designed accordingly, can be controlled to regulate the pressure profile and / or the timing of the actuator's filling. This allows for the setting of a desired speed profile of the plunger movement during each phase of the dispensing motion (also known as flank control). Advantageously, this further improves dosing accuracy, especially by effectively compensating for external influencing factors. For example, fluctuations in the dosing medium can be compensated for, which may be batch-dependent (viscosity), temperature-dependent, or due to material age (curing processes in adhesives). Furthermore, even small manufacturing tolerances or wear processes can be compensated for by flank control.

[0087] As mentioned, the throttling device can also be designed or controlled to regulate the pressure curve and / or the timing of the emptying process during actuator venting. This means that even during the retraction movement, the plunger can have two or more different speeds or a defined speed profile. The control can preferably be based on an input parameter, such as measurement data from the speed sensor, to achieve a predefined plunger speed profile. Advantageously, the plunger's retraction speed can be determined such that no air is drawn through the nozzle opening during the retraction movement, thus preventing the formation of air bubbles in the subsequent droplet of metering fluid ejected from the nozzle.

[0088] Preferably, the dosing system can be further configured to increase its uninterrupted operating time. For this purpose, the actuator unit can be designed to use the pressure medium flowing out of the actuator or actuator chamber as a cooling medium for cooling the control valve. Venting or emptying of the actuator chamber preferably occurs via the vent port of the control valve, with the vent port opening into a venting area of ​​the actuator unit.

[0089] The control valve, e.g., a solenoid valve, generates increasing heat during operation with increasing switching frequency, and overheating can lead to valve failure. Therefore, the venting area is preferably designed as a cavity within the housing of the metering system such that it completely surrounds or encloses the control valve from the outside. Preferably, the pressure medium can be routed past the control valve in such a way that as much heat as possible is dissipated from a surface of the control valve by means of the pressure medium. The pressure medium, e.g., compressed room air, is hardly heated as a result of passing through the actuator and can therefore be used as a cooling medium. The venting area, which could also be referred to as the cooling area, thus forms a cooling device for the metering system together with the pressure medium. The housing can have a bore to allow the pressure medium to drain from the venting area.

[0090] For particularly effective cooling of the control valve, the pressure medium could be actively cooled to a specific temperature before entering the housing, for example, using a cooling device. This would allow the control valve to be kept permanently below a critical operating temperature. Furthermore, the active cooling could also be controlled, for example, by incorporating a temperature sensor into the control valve and transmitting the corresponding readings to the control unit. The control unit could then activate the cooling device based on these readings, ensuring that the cooling device provides a sufficiently cooled pressure medium to maintain the control valve temperature below a critical value.

[0091] Advantageously, this cooling device ensures that the control valve is reliably kept below a critical operating temperature during operation, thereby improving the reliability of the dosing system. This makes it possible to operate the dosing system even at high ambient temperatures. Furthermore, the cycle frequencies of the dosing system can be increased compared to conventional dosing systems, as sufficient heat energy can be dissipated from the control valve even at very high cycle frequencies.

[0092] To further improve the reliability of the metering system, a pressure can be maintained in the area between the actuator diaphragm and a plunger seal, essentially corresponding to the cartridge pressure (pressure of the metering fluid in a metering fluid cartridge). The plunger seal surrounds the plunger and is implemented as part of the fluidic unit of the metering system. Preferably, the plunger seal is located opposite an outlet opening of the nozzle, with the plunger seal forming the upper boundary of a nozzle chamber. Because essentially the same pressure prevails on both sides of the plunger seal, the tendency for metering fluid to be forced through the seal during operation is counteracted. Advantageously, this increases the service life of the seal.

[0093] Alternatively, a negative pressure, in particular a vacuum, can be maintained between the actuator diaphragm, preferably its underside, and the plunger seal. Advantageously, this can increase the performance of the actuator or the metering system, as the vacuum facilitates or assists the deflection of the diaphragm towards the nozzle. This can be particularly advantageous with media that are difficult to meter, e.g., with metering substances of high viscosity.

[0094] To profitably implement the previously described advantageous designs of the metering system in operation, a method for controlling the metering system (control method) preferably involves controlling and / or regulating the pressure of the pressure medium flowing into the housing of the metering system or into the internal pressure tank by means of the metering system's pressure regulator, as a function of at least one input parameter, such that the velocity of the ejection element during an ejection movement, particularly upon impact with the nozzle, corresponds to a setpoint. Preferably, the pressure regulator is controlled by the metering system's control unit.

[0095] Preferably, the pressure of the pressure medium flowing into the actuator or actuator chamber and / or the pressure of the pressure medium flowing out of the actuator or actuator chamber is controlled and / or regulated by the throttling device of the metering system as a function of at least one input parameter, such that the velocity of the ejector element during a respective ejection and / or retraction movement corresponds to a setpoint value. Preferably, the control unit of the metering system can continuously receive measured values ​​from at least one sensor during operation, e.g., from the velocity sensor, in order to perform a real-time comparison of the measured values ​​(actual value) with a predefinable setpoint value. Based on this monitoring, the throttling device is then preferably controlled so that the pressure medium flows into or out of the actuator with a volume flow rate sufficient to achieve a desired plunger velocity during the ejection and / or retraction movement.

[0096] Furthermore, the control unit can actuate the throttling device such that the speed of the ejection element is varied during a single ejection stroke and / or during a single retraction stroke. Preferably, the ejection element can be accelerated to two or more different speeds for a single stroke. Preferably, depending on at least one input parameter, e.g., speed measurement data, the control unit can control the flow rate of the pressure medium through the throttling device such that a specific speed profile of the plunger is achieved during the ejection and / or retraction stroke.For example, the expansion valve can be controlled so that the actuator is first filled with a first pressure to achieve a first ejection velocity for a (single) ejection movement, and then filled with a second, different pressure to achieve a second ejection velocity, which may differ from the first ejection velocity.

[0097] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They schematically show: Figure 1 a cross-sectional view of a dosing system according to an embodiment of the invention, Figure 2 Parts of the dosing system made of Figure 1 in enlarged view, Figure 3 Parts of the dosing system made of Figure 1 and 2 in a further enlarged view, Figure 4 Parts of a dosing system shown in cross-section, similar Figure 3 , according to a further embodiment of the invention, Figure 5 a representation of an actuator unit of the dosing system according to an embodiment of the invention, Figure 6 a representation of the dosing system made of Figure 1 in a different functional position, Figure 7 a representation of a control method for a dosing system according to an embodiment of the invention, Figure 8 a representation of a velocity profile of a possible plunger movement according to an embodiment of the invention.

[0098] Based on Figure 1A specific embodiment of a dosing system 1 according to the invention will now be described. The dosing system 1 is shown here in cross-section in the position typical for its intended operation. A nozzle 70 is located in the lower region of the dosing system 1, so that the drops of the medium are ejected downwards through the nozzle 70 in an ejection direction RM. Therefore, wherever the terms "bottom" and "top" are used below, they always refer to this, usually typical, position of the dosing system 1. However, this does not preclude the possibility that the dosing system 1 can also be used in a different position in specific applications, with the drops being ejected laterally, for example. Depending on the medium, pressure, and the precise design and control of the entire ejection system, this is also fundamentally possible.

[0099] The dosing system 1 comprises as essential components an actuator unit 10 and a fluidic unit 60 coupled to it. The dosing system 1 shown here also includes a dosing agent cartridge 64, which is coupled to the fluidic unit 60.

[0100] In the embodiment of the dosing system 1 shown here, the actuator unit 10 and the fluid unit 60 are implemented as interlocking plug-in couplings to form a quick-release coupling. Advantageously, the actuator unit 10 and the fluid unit 60 can thus be coupled without tools to form the dosing system 1. The quick-release coupling comprises a coupling mechanism 50 with a coupling spring 51 that holds a ball 52 under constant preload. The coupling spring 51 and the ball 52 are enclosed here by a (first) actuator unit housing block 11a and form a first plug-in coupling component. This is particularly advantageous in Figure 2clearly shows which section of the dosing system is made up of Figure 1 shown in an enlarged view.

[0101] The clutch mechanism 50 has a number of ball caps 54 (in Figure 2 (only one shown), into which the ball 52 can snap for coupling. The spherical caps 54 are arranged in a second plug-in coupling part 53 of the fluidic unit 60, the fluidic unit 60 being enclosed by a (second) fluidic unit housing block 11b. For coupling, the first plug-in coupling part (of the actuator unit 10) and the second plug-in coupling part (of the fluidic unit 60) can be inserted into one another along a (virtual or imaginary) plug-in axis and thereby coupled to each other. For example, the fluidic unit 60 can be inserted against a direction RM (see Figure 1 ) are inserted into the actuator unit 10 and coupled to the actuator unit 10 in a suitable rotational position.

[0102] The ball caps 54 are arranged in the second plug-in coupling part 53 of the fluidic unit 60 such that different locking positions are possible, i.e., different rotational positions of the fluidic unit 60 around the plug-in axis are possible. The spring-loaded ball 52 engages the plug-in coupling part 53 in one of the several possible locking positions, thus forming the metering system 1.

[0103] The dosing system 1 therefore comprises a housing 11 with the two housing parts (housing blocks) 11a and 11b mentioned above.

[0104] However, it should be noted that the respective assemblies 10, 60 can also be firmly connected to each other, e.g. by means of a fixing screw, in order to form the housing 11.

[0105] As in Figure 1As can be seen, the actuator unit 10 essentially comprises all components that provide for the drive or movement of an ejection element 80, here a plunger 80, in the nozzle 70, i.e. e.g. a pneumatic actuator 12 to actuate the ejection element 80 of the fluidic unit 60, a control valve 20, a control unit (in Figure 1 and 2 (not shown), in order to control the pneumatic actuator 12 and similar components, as explained below.

[0106] The fluidic unit 60 comprises, in addition to the nozzle 70 and a supply line 62 for the medium to the nozzle 70, all other parts that are in direct contact with the medium, as well as the elements required to assemble the respective parts in contact with the medium and to hold them in their position on the fluidic unit 60. Furthermore, the fluidic unit 60 also includes means for returning the ejection element 80 to a rest or starting position after the metering material has been dispensed, as will be explained below.

[0107] Since the basic structure of dosing systems is known, for the sake of clarity, predominantly those components are shown here that at least indirectly relate to the invention.

[0108] In the embodiment shown here ( Figure 1 and 2The actuator unit 10 of the dosing system 1 comprises, as mentioned, a pneumatic actuator 12 that can be pressurized with a pressure medium, preferably compressed air. It should be noted that in the Figure 1 and 2 The pneumatics 12 and the coupling to the ejection element are shown only schematically. In particular, a diaphragm 13 of the actuator 12 is shown only schematically, i.e., not in a real position or configuration that the diaphragm 13 actually has during operation when deflected or retracted. This will be explained later using the Figures 3 and 4 explained.

[0109] The pneumatic actuator 12 ( Figure 1The fluidic unit 60 is coupled in such a way that, by means of a control signal to the pneumatic actuator 12, the plunger 80 is actuated so that the fluidic unit 60 ejects a metered medium in the desired quantity at the desired time. In the case shown here, the plunger 80 currently closes a nozzle opening 72 and thus also serves as a closing element 80. However, since most of the medium is already ejected from the nozzle opening 72 when the plunger 80 is in an ejection direction RA (see Figure 2 The part that is moved is referred to here as the ejection element 80. The coupling between pneumatic actuator 12 and plunger 80 will be described later using the following: Figure 3 explained in detail.

[0110] The pneumatic actuator 12 is arranged in the actuator unit 10 in close proximity to a control valve 20 for controlling the actuator 12. The control valve 20, e.g., a pneumatic 3 / 2-way valve, is designed to supply a pressure medium, e.g., compressed room air, to the actuator 12 and / or to discharge a pressure medium from the actuator 12. For this purpose, the actuator 12 is arranged in the actuator unit 10 such that a bore 17 of the actuator 12 interacts with, or is spatially connected to, a working port 23 of the control valve 20. This is particularly advantageous in Figure 2 clearly.

[0111] The control valve 20 further comprises a compressed air connection 22 and a vent connection 24, whereby, depending on the control or switching position of the control valve 20, either the compressed air connection 22 or the vent connection 24 interacts with or is connected to the working connection 23. The control valve 20 is coupled to a circuit board 42 of the dosing system by means of a connecting cable 21 and can be controlled via this connection by a control unit of the dosing system 1 (e.g., electrically) (see Figure 1 ).

[0112] In Figure 2It can be seen that the control valve 20 is arranged in the actuator unit 10 such that the compressed air connection 22 interacts with or is connected to a bore 25 (here, top left), with the bore 25 and the compressed air connection 22 having essentially the same diameter. The bore 25 here serves as the discharge opening 25 of an internal pressure reservoir 32 (hereinafter also referred to as pressure tank 32) of the metering system 1. A pressure medium can be supplied to the control valve 20 (via the compressed air connection 22) and subsequently also to the actuator 12 (via the working connection 23 and the bore 17) through this bore 25.

[0113] The pressure tank 32 is directly adjacent to the control valve 20. Therefore, apart from the bore 25, no connecting lines are required between the pressure tank 32 and the control valve 20, thus largely preventing pressure losses in the pressure medium. Within the housing block 11a, the pressure tank 32 extends between the discharge opening 25 and a pressure medium supply device 30, which includes a coupling point 31 for an external pressure medium supply (not shown) (see Figure 1 ) and represents a cavity or chamber in the dosing system 1. A pressure medium at a specific pressure can be supplied to the pressure reservoir 32 in one direction RD by means of the pressure medium supply device 30. Unlike what is shown here, an external pressure medium supply line can also include a controllable pressure regulator, as will be shown in more detail below. Figure 7 will be explained.

[0114] The pressure tank 32 is designed to maintain a pressure medium DK at a specific pressure during operation, particularly in conjunction with the pressure medium supply device 30 and the pressure regulator (see Figure 6 The pressure of the pressure medium in the pressure tank 32 corresponds to the supply pressure of the actuator 12.

[0115] The pressure tank 32 includes a pressure sensor 33 to determine the pressure of the pressure medium in the pressure tank 32 (see Figure 1The pressure sensor 33 is mounted on a circuit board 42 of the dosing system 1. The circuit board 42 may also include or be connected to various other electronic components, such as a temperature sensor 48 or a heating device 47. The circuit board 42 is connected to a terminal assembly 40, which includes a coupling point 41 for a connecting cable of the control unit (not shown). The coupling point 41, for example, a connector socket, allows the measurement signals from the pressure sensor 33 or other sensors to be supplied to the control unit of the dosing system 1. Conversely, the control unit can access the various electrical components of the dosing system 1 via the terminal assembly 40, for example, to control the heating device 47. Furthermore, the control unit can also control the control valve 20 via the terminal assembly 40, the circuit board 42, and the connecting cable 21.

[0116] Out of Figure 1 It further emerges that the control valve 20 comprises a vent port 24 which interacts with or is connected to a bore 26 (here top right) of a venting area 34 of the metering system 1, wherein the bore 26 and the vent port 24 have essentially the same diameter. A pressure medium can be discharged from the actuator 12 via the vent port 24 and the bore 26 and can advantageously also be used to cool the control valve 20. The venting area 34 will be described later with reference to Figure 6 explained in more detail.

[0117] To operate the pneumatic actuator 12 as desired, the control valve 20 can be controlled by the control unit of the dosing system 1. The in Figure 1The control valve 20 shown (hereinafter also referred to as "pneumatic valve") could, for example, be a pneumatic 3 / 2-way solenoid valve with a normally open position (position "filling"). Accordingly, in a normal position of the pneumatic valve 20, the pressure medium can be directed from the pressure reservoir 32 via the compressed air connection 22 and a flow channel 27 located in the pneumatic valve 20 (shown here as a dashed line) to the working port 23. In this first switching position of the control valve 20, the pressure medium flows into an actuator chamber of the actuator 12 at the pressure prevailing in the pressure reservoir 32 (supply pressure) in order to deflect a diaphragm of the actuator 12 and thus the plunger 80 downwards in an ejection direction of the plunger 80, whereby a droplet of the metering medium is ejected from the nozzle 70.

[0118] This means that in a normal position (first switching position) of the pneumatic valve 20, the actuator 12 is under a certain pressure, with a plunger tip 82 of the plunger 80 in contact with a sealing seat 73 of the nozzle 70, i.e., the nozzle 70 or the metering system 1 is closed (see also Figure 2 However, unlike what is shown here, it is also possible that the plunger tip 82, in the normal position of the solenoid valve 20, i.e. at maximum deflection of the diaphragm, does not fully strike the nozzle 70, whereby the ejection movement of the plunger 80 is stopped beforehand, i.e. at a distance from the nozzle 70.

[0119] In the Figure 2In the case shown, the actuator 12 is filled with the pressure applied directly upstream of the control valve 20; that is, the supply pressure of the actuator 12 also corresponds to the actuator filling pressure. However, it is also possible to fill the actuator 12 with a lower pressure than the supply pressure and / or to fill the actuator 12 with a dynamic pressure profile. This allows, for example, the realization of a specific velocity profile during the ejection movement of the plunger 80. To achieve this, the metering system 1, e.g., the solenoid valve 20, could be supplemented by one or more controllable actuators with variable flow rates, e.g., piezoelectric actuators. Such an actuator could, for example, be arranged in the area of ​​the working port 23 (not shown).

[0120] To return the actuator 12 to a rest position after the metering agent has been dispensed, the pneumatic valve 20 can be switched by the control unit so that the working port 23 is closed by means of an internal flow channel 27' (see Figure 6 ) of the solenoid valve 20 is connected to the vent port 24 (second switching position). The pressure medium then flows into the venting area of ​​the actuator unit 10. This will be explained later using Figure 6 explained.

[0121] As mentioned, the actuator 12 is in its rest position when both the diaphragm 13 and the ejector element 80 are in a rest position. The diaphragm 13 of the actuator 12, which is currently not pressurized, returns to its rest position due to its inherent tension. To also return the plunger 80 to a rest position, so that the nozzle opening 70 is released, a plunger head 81 of the plunger 80 is pushed upwards towards the control valve 20 by means of a return spring 84. The exact operating principle of the actuator 12 will be explained later with reference to the Figures 3 and 4 Explained in detail.

[0122] Out of Figure 2It becomes particularly clear that the fluidic unit 60 of the metering system 1 comprises a second housing part 11b and, as mentioned, is connected to the actuator unit 10, or rather its housing part 11a, by means of a quick-release coupling to form the housing 11. The fluidic unit 60 comprises the plunger 80, which, with a contact surface 86 of the plunger head 81, bears directly against a side surface (underside) of the diaphragm 13 of the actuator 12 facing towards the plunger 80. The plunger 80 is, as is generally preferred in the metering system, formed in one piece. For coupling to the actuator unit 10 (only partially shown), the plunger 80, in particular the plunger head 81, is pressed upwards in the axial direction against the diaphragm 13 by means of a spring 84. The return spring 84 rests on a tappet bearing 83, to which a tappet seal 85 is attached below. In this ( Figure 2In the case shown, the diaphragm 13 (shown schematically) of the actuator 12 is pressurized with pressure medium (operating position of the actuator 12), so that the plunger tip 82 rests against the sealing seat 73 of the nozzle 70.

[0123] If the actuator 12 is in a rest position other than shown here, i.e., the diaphragm 13 of the actuator 12 is not pressurized or deflected, the plunger tip 82 is pushed away from the sealing seat 73 of the nozzle 70 by the return spring 84. The plunger tip 82 is then located at a distance from the sealing seat 73 of the nozzle 70, so that the nozzle opening 72 is free or unblocked.

[0124] The metering material is supplied to the nozzle 70 via a nozzle chamber 71, to which a supply channel 62 leads (see Figure 2The feed channel 62 is embedded here in a fluidic body 61. The feed channel 62 is also connected to a metering cartridge 64. The feed channel 62 is closed externally by a clamping screw 65. The metering cartridge 64 is reversibly attached to the housing 11 at a coupling point 63. Furthermore, the cartridge 64 is attached to the actuator unit 10 by means of a retaining element 45 (see Figure 1 ).

[0125] To heat the metering material in the area of ​​the nozzle 70 to a specific processing temperature, the metering system 1 comprises at least one heating device 47, e.g., one or more heating plates 47 or heating foils 47. This is particularly evident in the enlarged view in Figure 2Clearly, the heating device 47 can be controlled by the control unit. Here, the heating device 47 is integrated into the actuator unit 10 and initially heats the coupling part of the actuator unit 10, i.e., for example, the coupling mechanism 50. As soon as the plug-in coupling part 53 of the fluid unit 60 is inserted into the coupling part of the actuator unit 10, the plug-in coupling part 53, and in particular the metering fluid in the nozzle 70, is heated to a specific temperature. The plug-in coupling part 53 is designed to ensure the best possible heat conduction towards the nozzle 70. The fluid unit 60 does not include a separate heating device and can therefore be easily handled or disassembled even during operation.

[0126] To protect the pneumatic actuator 12 and, in particular, the control valve 20 from overheating, the dosing system 1 incorporates extensive thermal decoupling of the heating unit 47 from the pneumatic actuator 12. When the dosing system is installed as intended, i.e., when the fluid unit 60 and the actuator unit 10 are installed as shown in the diagram, the heating unit 47 is thermally decoupled from the pneumatic actuator 12. Figure 2 The metering system 1, which is shown coupled together, comprises several gas-filled cavities 46, 46'. The cavities 46, 46' serve to thermally decouple the pneumatic actuator 12 from the fluidic unit 60. By means of these cavities 46, 46', heat conduction from the heating device 47 towards the actuator unit 10 or the control valve 20 can be effectively prevented.

[0127] Figure 3 shows a further enlarged part of the dosing system 1 according to the Figure 1 and 2 However, dosing system 1 is shown here at a different stage of the dosing process. As explained previously, the Figure 1 and 2 The dosing system 1 during an ejection process of metering material from the nozzle. The nozzle 70 of the dosing system is ( Figure 1 and 2 ) closed by the plunger 80. In contrast, it shows Figure 3 A pneumatic actuator 12 is in a rest position, i.e., the diaphragm 13 of the actuator 12 is not deflected, and the ejection element 80 is also in a rest position. According to the pneumatic actuator 12... Figure 3 The nozzle 70 is therefore not closed by the ejection element 80.

[0128] The pneumatic actuator 12 from Figure 3The actuator 12 is in direct operative contact with the working port 23 of the pneumatic valve 20 via the bore 17. As mentioned, the actuator 12 comprises a rigid actuator body 14, which here is formed by means of two components 14a, 14b. The two components 14a, 14b are arranged relative to each other, preferably in a fixed position, such that they form a cavity between them in cross-section. In contrast, the two actuator body parts 14a, 14b rest directly on each other in an outer area of ​​the respective component 14a, 14b and are detachably pressed against each other there, so that the diaphragm 13 can be replaced if necessary.

[0129] To form an actuator chamber 16 of the actuator 12, an (actuating) diaphragm 13 is arranged, as mentioned, in a sealed manner between the two rigid base body parts 14a and 14b. It is clear here that the actuator 12 comprises only a single diaphragm 13 for moving the plunger 80. The diaphragm 13 is shown here in a rest position and is curved upwards in a central area where the ejection element 80 of the diaphragm 13 rests. The spring 84 or the ejection element 80 presses the diaphragm 13 against the upper actuator base body 14a, to which the diaphragm 13 rests, at least partially. The actuator base body 14a thus limits the stroke or deflection of the diaphragm 13 upwards. However, it is also conceivable that the actuator 12 is designed in such a way that the membrane also rests against the upper actuator body 14a at least in certain areas, even in a predominantly horizontal resting position, e.g.by the actuator body 14a having a projection or bulge in the area of ​​the plunger head 81 pointing towards the membrane 13 (not shown).

[0130] Even if this is evident from the sectional view according to Figure 3 Unless otherwise indicated, the membrane 13 preferably has a circular base and is completely gas-tightly coupled to the two base body parts 14a, 14b of the rigid base body 14 at its perimeter. For this purpose, the membrane 13 is pressed against the upper base body component 14a from below at its perimeter by means of the lower base body component 14b. A sealing ring 15, e.g., an O-ring 15, is arranged between the membrane 13 and the upper component 14a for sealing.

[0131] As mentioned, the actuator chamber 16 of the actuator 12 is formed here between a side surface (top) of the membrane 13 facing away from the ejection element 80 and the rigid actuator body part 14a at the top. The actuator chamber 16 can be filled with a pressure medium via the bore 17 in order to deflect the membrane 13 downwards from the rest position shown here. This will be explained later using Figure 4 shown schematically once again.

[0132] To couple the ejection element 80 to the actuator unit, the plunger head 81 is pressed against the underside 19 of the diaphragm 13 by means of a spring 84. The return spring 84 is designed such that it exerts a (spring) force on the plunger 80 that it remains in direct contact with the underside 19 even when the actuator 12 is in a rest position. In the case shown here, the plunger 80 pushes the diaphragm 13 (at least a central region of the diaphragm 13) upwards beyond a horizontal rest position, with the deflection being limited by component 14a.

[0133] Figure 4 Figure 1 shows a section of a dosing system shown in cross-section according to a further embodiment. The difference to the dosing systems shown so far (Figures 1 to 3) is that the pneumatic actuator 12 here additionally includes a sensor 18 for determining the speed of a movement of the ejection element 80.

[0134] The sensor 18 is positioned in the upper actuator body part 14a such that it lies on an imaginary vertical line (corresponding to the longitudinal extent of the plunger 80) with the plunger 80. The sensor 18 and the plunger head 81 are located directly opposite each other on opposite sides of the diaphragm 13. To determine the velocity of the plunger 80 during each phase of the ejection and / or retraction movement, the sensor 18 can include a position sensor 18 to detect the distance between the sensor 18 and the plunger head 81 as a function of time. For example, the sensor 18 can be a Hall sensor, with the plunger head 81 including a magnet (not shown). To transmit the measurement data, the sensor 18 is coupled to the control unit of the dosing system 1 (not shown here).

[0135] In the detailed view of Figure 4It becomes further clear that membrane 13 is deformed to release the dosing agent. As in the Figure 1 and 2 The actuator 12 is also shown here in an operating position. This means that the upper surface of the diaphragm 13 is currently pressurized with a pressure medium. As can be seen here, the diaphragm 13 is not deflected evenly or uniformly downwards towards the plunger 80 due to the pressure. Rather, there are areas of the diaphragm 13 that move downwards more significantly and other areas that hardly change position.

[0136] Due to its design, the edge regions of the diaphragm 13, where it is coupled to the actuator body 14, are hardly deflected. Furthermore, the area of ​​the diaphragm 13 that rests against the plunger head 81 is also deflected relatively little. This is because the plunger 80 is pressed against the underside 19 of the diaphragm 13 by the spring 84. The spring 84 thus exerts a certain force against the deflection of the diaphragm 13. However, the spring 84 is designed such that the diaphragm 13 overcomes the spring force of the spring 84 during deflection and deflects the plunger 80 by a desired amount towards the nozzle to dispense the metering material.

[0137] In contrast, the central areas of the membrane 13, which lie in the cross-section shown between the plunger head 81 and the edge of the membrane 13, experience a relatively strong downward deflection. During this deflection, the membrane 13 is thus deformed in a virtually "wave-like" manner.

[0138] Figure 5 Figure 10 shows, in a rough schematic fashion, the structure and control of the actuator unit according to one embodiment of the invention. The actuator unit 10 comprises an internal pressure reservoir 32, which holds pressure medium at a specific supply pressure. The pressure medium is supplied to a control valve 20 in a flow direction RD. The control valve 20 is actuated by a control unit (not shown) such that the pressure medium flows in a direction RD' into an actuator chamber 16 of a pneumatic actuator 12. Depending on the configuration of the actuator unit 10, an optional throttling device (not shown) can be controlled such that the actuator chamber 16 is filled with pressure medium at a supply pressure or at a different actuator filling pressure.

[0139] Due to the application of pressure medium, the membrane 13 and thus also the ejection element 80 for metering substance release is deflected downwards in a direction RA.

[0140] In the next step, the control unit actuates the control valve 20 so that the actuator chamber 16 is vented immediately after the metering fluid has been dispensed. The pressure medium leaves the actuator chamber 16 in a flow direction RD" and flows into the control valve 20 before exiting it in a direction RD‴. Due to the pressure reduction in the actuator chamber 16, the diaphragm 13 swings back to its rest position. The ejection element 80 immediately or simultaneously follows the movement of the diaphragm 13—if necessary, the ejection element 80 even assists the movement of the diaphragm 13—and is returned to its rest position by means of a spring 84. This completes one metering fluid dispensing cycle.

[0141] Figure 6 The dosing system is shown from the Figures 1 to 3During venting of the pneumatic actuator. The control valve 20 is actuated by the control unit (not shown) such that the working port 23 interacts with the vent port 24. For this purpose, the control valve 20 is moved into a second switching position, so that a flow channel 27' (shown here as a dashed line) inside the control valve 20 connects the two ports 23 and 24. The pressure medium flows out of the actuator 12 via the bore 17 and is guided through the flow channel 27' to the vent port 24 and finally into the venting area 34. The plunger 80 is pushed upwards away from the nozzle 70 towards the actuator unit 10 by the spring 84, so that a small gap forms between the plunger tip 82 and the sealing seat 72 (not shown). Membrane 13 is shown here in a horizontal "intermediate position", i.e., the membrane is currently returning to a rest position as a result of the venting of the actuator chamber.

[0142] The venting area 34 represents a cavity or chamber within the housing of the actuator unit 10. In this illustration, the chamber of the venting area 34 is obscured by the inflowing pressure medium DE. The pressure medium in the venting area 34 has a lower pressure than the actuator supply pressure and is therefore referred to as expanded pressure medium DE. The venting area 34 is directly adjacent to the control valve 20 via the bore 26 and also has a bore leading outside the metering system (not shown). As shown here, the venting area 34 surrounds a substantial portion of the control valve 20 from the outside.

[0143] The venting area 34 is spatially and control-technically separated from the pressure tank 32 of the actuator unit 10. The pressure tank 32 is filled with a compressed pressure medium DK, whereby a chamber forming the pressure tank 32 is covered by the pressure medium DK.

[0144] The pressure medium flowing into the venting area 34 can be guided past the control valve, e.g., by means of flow-guiding elements, in order to dissipate as much heat as possible from a surface of the control valve 20. The pressure medium, e.g., compressed room air, is hardly heated as a result of passing through the actuator 12 and can therefore be used as a cooling medium. Due to the comparatively large volume of the venting area 34, especially compared to the actuator chamber, the pressure of the pressure medium in the venting area 34 can be significantly lower than, for example, in the pressure reservoir 32 and / or in the actuator chamber.

[0145] Figure 7Figure 1 shows a schematic representation of a control method for a dosing system 1 according to an embodiment of the invention. The dosing system 1 comprises a housing 11 in which the essential components of the actuator unit 10 and the fluid unit are enclosed. The dosing system 1 further comprises a control unit 43 with a number of connecting cables 44 for separately controlling the respective components of the dosing system 1.

[0146] The control unit 43 is coupled to a pressure regulator 35 to control and / or regulate the pressure of the pressure medium flowing into the internal pressure tank 32. The pressure regulator 35 is coupled to a pressure medium supply 37 and is, for example, located on the outside of the housing 11 of the dosing system 1 as a component of the actuator unit 10. An external pressure reservoir 36 is optionally arranged between the pressure regulator 35 and the internal pressure tank 32. The pressure regulator 35 can be controlled by the control unit 43, preferably depending on input parameters, such as a plunger speed, so that a specific pressure is maintained in the external pressure tank 36 or in the internal pressure tank 32 to achieve a constant plunger speed during the dispensing process.

[0147] To control the actuator 12, the control unit 43 can, on the other hand, control the control valve 20 to fill the actuator chamber of the actuator 12 (using the pressure medium from the internal pressure tank 32) or to vent it (using a pressure medium outlet DA). The actuator 12 of the dosing system 1 is coupled to a sensor 18, e.g., a position sensor 18, with the measurement data being transmitted to the control unit 43 as input parameters.

[0148] The control unit 43 can process these and other input parameters, e.g., from a pressure sensor in the internal pressure tank 32, and use them to control and / or regulate the ram speed or its profile ("edge control"). Depending on the measured values, the control unit 43 can, for example, control the pressure regulator 35 so that a specific target pressure of the pressure medium (supply pressure) is maintained in the internal pressure tank 32 in order to achieve a constant ram speed.

[0149] Alternatively or additionally, the control unit 43 can control a throttling device 28 to regulate the flow of the pressure medium, e.g. with a piezoelectric actuator 28, here in the area of ​​the control valve 20, depending on input parameters, in order to achieve a certain plunger speed or a desired speed profile during the ejection and / or retraction movement of the plunger 80.

[0150] The control unit 43 can further control a heating device 47 of the metering system 1 to heat the metering substance in the nozzle 70 to a target temperature. Preferably, the control unit 43 can control and / or regulate the heating device 47 depending on a temperature measurement, wherein the temperature measurement is determined by means of a temperature sensor 48.

[0151] The control unit 43 can also access a second pressure regulator 35', which controls the pressure of the pressure medium in the dosing agent cartridge 64 (cartridge pressure).

[0152] Figure 8 Figure 1 schematically shows a representation of the velocity profile of a possible plunger movement according to one embodiment of the invention. The control of the velocity profile is also referred to as flank control. The figure depicts the relative position PS of the plunger tip in relation to a relative time t of the ejection process. The position PD of the nozzle's sealing seat in the metering system is shown here with a dashed line.

[0153] Before the ejection process begins, at time T1, the plunger is in a rest position. This means that the tip of the plunger is at its maximum possible distance from the nozzle, so that the nozzle of the metering system is unblocked.

[0154] At time T2, the actuator is filled with a pressure medium at high pressure, resulting in a high ejection velocity of the plunger. For example, a piezoelectric actuator could be fully open to allow maximum airflow.

[0155] At time T3, e.g., shortly before the plunger tip impacts the nozzle's sealing seat, the plunger's ejection velocity is slowed. This is achieved, for example, by reducing the airflow through the pneumatic actuator. Consequently, the plunger tip impacts the nozzle's sealing seat at time T4 with a lower velocity, which can improve metering accuracy for certain dispensing materials.

[0156] For the sake of completeness, it should be noted that such control of the flanks is of course also possible during a retraction movement of the plunger.

[0157] Finally, it should be noted once again that the dosing systems described in detail above are merely exemplary embodiments which can be modified in various ways by those skilled in the art without departing from the scope of the invention. For example, the dosing system can include additional sensors for determining relevant operating parameters, such as a sensor for determining the temperature of the control valve. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Reference symbol list

[0158] 1 Dosing system 10 Actuator unit 11 Housing 11a, 11b Housing block / Housing components 12 Actuator 13 Diaphragm 14 Actuator base body 14a, 14b Components of the actuator base body 15 Actuator sealing ring 16 Actuator chamber 17 Actuator chamber bore 18 Sensor 19 Diaphragm underside 20 Control valve 21 Control valve connection cable 22 Compressed air connection 23 Working connection 24 Vent connection 25 Discharge opening / Pressure tank bore 26 Vent area bore 27, 27' Flow channel 28 Throttle device 30 Pressure medium supply device 31 Coupling point 32 Pressure reservoir 33 Pressure sensor 34 Vent area / Cooling device 35, 35' Pressure regulator 36 External pressure reservoir 37 Pressure medium supply 40 Connection 41 Coupling point for connecting cable 42 Circuit board 43 Control unit 44 Connecting cable of the control unit 45 Retaining element 46,46' Cavity 47 Heating element 48 Temperature sensor 50 Coupling mechanism 51 Coupling spring 52 Ball 53 Plug-in coupling part 54 Ball cap 60 Fluidic unit 61 Fluidic body 62 Feed channel 63 Coupling point of the media cartridge 64 Media cartridge 65 Clamping screw 70 Nozzle 71 Nozzle chamber 72 Outlet opening 73 Sealing seat 80 Ejection element / plunger 81 Plunger head 82 Plunger tip 83 Plunger bearing 84 Plunger spring 85 Plunger seal 86 Contact surface DE Pressure medium expands DK Pressure medium compresses DA Pressure medium outlet PD Position of the sealing seat PS Position of the plunger tip RA Plunger ejection direction RD, RD', RD", RD‴ Pressure medium flow direction RM Metering material ejection direction t Time of ejection movement T 1 , T 2 , T 3, T4 Time,

Claims

1. A dosing system (1) for dosing a dosing material, which dosing system (1) has a housing (11) comprising a nozzle (70) and a supply channel (62) for dosing material, and a discharge element (80) movably mounted in the housing (11) and an actuator unit (10) coupled to the discharge element, characterized in that - the actuator unit (10) comprises an actuator (12) having a membrane (13) which can be pressurized by means of a pressure medium to move the discharge element (80) in a discharge direction (RA), wherein gaseous and / or liquid substances are used as pressure medium, and in that - the discharge element (80) is formed separately and is pressed against a side surface (19) of the membrane (13) pointing in the direction of the discharge element (80) by means of a force acting on the discharge element (80) for coupling to the actuator unit (10).

2. The dosing system according to claim 1, wherein the dosing system (1) is formed so that the force acting on the discharge element (80) for coupling is directed in the opposite direction to a discharge direction (RA) of the discharge element (80).

3. The dosing system according to claim 1 or 2, wherein the dosing system (1) is formed so that the discharge element (80) is pressed against the side surface (19) of the membrane (13) by means of at least one spring arrangement (84) for coupling to the actuator unit (10).

4. The dosing system according to one of the preceding claims 1 to 3, wherein the membrane (13) is formed like a disk and / or free of cavities.

5. The dosing system according to one of the preceding claims 1 to 4, wherein the housing (11) of the dosing system (1) comprises a reservoir (32) for the pressure medium and / or wherein the reservoir (32) directly adjoins a control valve (20) of the actuator unit (10) for controlling the actuator (12).

6. The dosing system according to claim 5, wherein at least one pressure sensor (33) is arranged in the reservoir (32).

7. The dosing system according to claim 5 or 6, wherein the actuator unit (10) is formed to use a pressure medium flowing out of an actuator chamber (16) of the actuator (12) as a cooling medium for cooling the control valve (20).

8. The dosing system according to one of the preceding claims 1 to 7, wherein the dosing system (1) comprises at least one sensor (18) for measuring a speed of a movement of the discharge element (80).

9. The dosing system according to one of the preceding claims 1 to 8, wherein the dosing system (1) comprises at least one pressure regulator (35) to control and / or regulate a pressure of the pressure medium as a function of an input parameter, preferably by means of a control and / or regulating unit (43) of the dosing system (1).

10. The dosing system according to one of the preceding claims 1 to 9, wherein the dosing system (1), preferably a control valve (20) of the dosing system (1) for controlling the actuator (12), comprises at least one throttle device (28) which is formed to control and / or regulate a pressure in the actuator (12) as a function of an input parameter, preferably by means of a control and / or regulating unit (43) of the dosing system (1).

11. The dosing system according to one of the preceding claims 1 to 10, wherein the dosing system (1), preferably a control valve (20) of the dosing system (1) for controlling the actuator (12), comprises at least one throttle device (28) which is formed to control and / or regulate a pressure profile during a filling of the actuator (12) and / or during emptying of the actuator (12).

12. The dosing system according to one of the preceding claims 1 to 11, wherein the dosing system (1) is formed such that a pressure is maintained in a region between the membrane (13) and a plunger seal (85), which pressure essentially corresponds to a cartridge pressure and / or wherein the dosing system (1) is formed such that a negative pressure, in particular a vacuum, is maintained in a region between the membrane (13), preferably its underside, and the plunger seal (85).

13. A method for controlling a dosing system (1) for dosing a dosing material, which dosing system (1) has a housing (11) comprising a nozzle (70) and a supply channel (62) for dosing material, and a discharge element (80) movably mounted in the housing (11) and an actuator unit (10) coupled to the discharge element, - a membrane (13) of an actuator (12) of the actuator unit (10) being pressurized by a pressure medium to move the discharge element (80) in a discharge direction (RA) wherein gaseous and / or liquid substances are used as pressure medium, and - the discharge element (80) being pressed against a side surface (19) of the membrane (13) pointing in the direction of the discharge element (80) by means of a force acting on the discharge element (80) for coupling to the actuator unit (10).

14. The method according to claim 13, wherein a pressure of the pressure medium is controlled and / or regulated as a function of an input parameter so that a speed of the discharge element (80) corresponds to a target value during a discharge movement.

15. The method according to claim 13 or 14, wherein a pressure of a pressure medium flowing into the actuator (12) and / or a pressure of a pressure medium flowing out of the actuator (12) is controlled and / or regulated as a function of an input parameter so that a speed of the discharge element (80) corresponds to a target value during a discharge movement and / or a retraction movement.

16. The method according to one of the claims 13 to 15, wherein a pressure of the pressure medium is controlled and / or regulated, preferably a throttle device (28) of the dosing system (1) is controlled by means of a control and / or regulating unit (43) of the dosing system (1) so that a speed of the discharge element (80) is varied during a discharge movement and / or during a retraction movement.