Metering system

Abstract

The present invention relates to a metering system (1) having a housing (2), a piezoelectric actuator (10) located therein, a fluid unit (15) having a valve (16), a plunger device (40) for closing the valve (16), and a transmission lever (20) for connecting the piezoelectric actuator (10) to the plunger device (40), wherein the piezoelectric actuator (10) is arranged within the housing (2) next to and generally parallel to the plunger device (40), the piezoelectric actuator (10) extending substantially in a direction towards the valve (16) and away from the transmission lever (20).

Description

[Technical Field]

[0001] The present invention relates to a metering system comprising a housing, a piezo actuator located therein, a fluid unit having a valve, a plunger device for closing the valve, and a transmission lever for connecting the piezo actuator to the plunger device. [Background technology]

[0002] Metering systems are typically used to meter materials to be metered, generally ranging from liquids to semi-fluid metering substances, in a targeted manner, for example, by discharging the metering material in droplet form or metering point form via a plunger device through a valve in the metering system. Thus, by such discharging, a metering point or "dub" (droplet) can be positioned on the workpiece in a single metering step (which can be very simply described in a single opening operation of the plunger device).

[0003] In so-called “micrometering techniques,” it is often necessary that a very small amount of metering material or substance be applied to the target surface in a precisely accurate and non-contact manner, i.e., without direct contact between the metering system and the target surface. Such non-contact methods are often also called “jet methods.” Common examples of this include metering of adhesive dots, solder paste, etc., when mounting circuit boards or other electronic components, or the application of converter materials for LEDs.

[0004] From European Patent Application Publication No. 1 414 080, for example, a piezoelectric actuator system, or a positioning system having a piezo actuator and an integrated lever transmission, is known, in which the piezo actuator extends away from the transmission lever on the side facing away from the valve. This arrangement has the disadvantage that the actuator system is lengthened, or must be lengthened in a manner related to the design. A metering system in which a piezo actuator extends substantially parallel to the tappet, away from the transmission lever, on the side facing away from the valve, is known from Korean Registered Patent No. 10-819077, U.S. Patent Application Publication No. 2019 / 022692, and Chinese Patent No. 102935416. In Korean Registered Patent No. 10-819077 and U.S. Patent Application Publication No. 2019 / 022692, the tappet is biased against the housing via a single spring, which means that the tappet is always biased to the closed position. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, the object of the present invention is to overcome the disadvantages of the prior art and to provide a particularly compact metering system. [Means for solving the problem]

[0006] This problem is solved by the metering system according to claim 1 of the patent claims.

[0007] As described in the introduction, the metering system comprises a housing. The housing is understood to mean both a primarily closed outer casing and an internal structure in which the components located within it are properly housed.

[0008] One of these components is the elongated piezo actuator already mentioned in the introduction. To open and close a valve, it helps generate a pulse or metering motion which is transmitted to a plunger device via a transmission lever. For this purpose, the piezo actuator can be advantageously fitted into a housing. Here, it may preferably also have encapsulation, i.e., the actual piezo or piezo stack can be encapsulated to protect it from moisture. The encapsulated piezo actuator can then be cooled more effectively.

[0009] The valves of the fluid unit described above can relate in particular to so-called “jet valves,” and therefore to valves suitable for “jetting,” or can operate in a jet manner. In this mode of operation, the plunger device serves primarily as a discharge element, i.e., assists in the movement of the plunger toward the valve seat or the sealing seat of the valve, and the metering material or metering substance is ejected by the plunger. Additionally or alternatively, a part of the plunger device can also function as an actual closing element that closes the valve in the course of the metering operation, respectively, by the plunger pressing into the valve seat at the position of its end at that end. After the discharge of the desired amount of metering, the valve is opened and closed again by easily pulling the plunger away from the valve seat, when other forces relating to the environment, such as gravity and / or increased pressure inside the valve, can cause the metering material to exit the valve and therefore can be metered. Depending on the application, the plunger device can here operate by the plunger of the plunger device, which serves as a closing element and / or a discharge element (“jetting”) of the valve in different types of functions. Both types of functionality can have practical relevance.

[0010] Furthermore, the transmission lever is housed within the housing. This helps to connect the piezo actuator to the plunger device. The transmission lever can also be mounted to a lever bearing in the housing via a shaft, and as a result, the transmission lever can be tilted relative to the shaft or the tilt axis.

[0011] The shaft may relate to a linear contact bearing or a roller bearing, for example, as already known from European Patent Application Publication No. 1 414 080.

[0012] As described in the introduction, the fluid unit with a valve can be configured, for example, to be connected to a housing to substantially supply metering material to the metering system, and as a result, the metering material can be released by a plunger device through the valve at the desired metering. Except for the plunger device portion (as will be further described below), the fluid unit substantially comprises all the elements useful for supplying metering material, temperature control, etc.

[0013] The piezo actuator is positioned here approximately next to the plunger device in the housing, and in particular, side by side. The term "approximately next to" means that the two components are spatially close to each other.

[0014] According to the present invention, the piezo actuator extends substantially toward the valve in the direction of the valve facing the valve, away from the transmission lever. That is, the piezo actuator and plunger device extend within the housing adjacent to each other, or substantially parallel to each other, away from one of the two lever arms of the transmission lever. In addition, the piezo actuator is tensioned against the housing via a plunger device through the transmission lever by a spring arrangement. Furthermore, the spring arrangement has several springs or spring elements for spring tensioning of the plunger device.

[0015] In this regard, for the sake of brevity, it is noted below, without loss of generality, that the direction to the valve is also indicated as the downward direction and the direction away from the valve, and the direction to the transmission lever is specified as the upward direction. The metering system is not shown in the metering in this configuration, but information regarding relative directions such as “up” and “down” (more of which are listed further below) will therefore be understood as appropriate.

[0016] The arrangement according to the present invention enables a particularly compact structure, thereby allowing the metering system as a whole to be significantly shorter than that possible with solutions known from the prior art. It utilizes the space within the housing in an optimal manner, and as a result, longer components such as elongated plunger devices or piezo actuators do not require unnecessary space, i.e., they do not substantially increase in length with respect to what had previously been the case in prior art structures.

[0017] In addition, the structure according to the present invention can be used to create additional space in the longitudinal direction, such that the essential closing part of the entire metering system, i.e., the plunger of the plunger device, which functions as a closing or discharge element depending on the selected type of function of the operation of the metering system (as further described below), can be easily and quickly installed by the customer in a replaceable manner. In addition, although the metering system is originally designed in its structural type for so-called “normally closed operation,” i.e., “operation or metering operation that is closed in an initial position,” the metering system can therefore also use components (e.g., plungers and fluid units) that are currently available for both normally open and normally closed metering systems, having the same length. In a normally open or open ("normally open") valve in the unenergized state of the metering system, the closing element is not pressed into the sealing seat in the valve (if no voltage is applied to the metering system), but rather has a short distance therefrom. If power is supplied to such a metering system and metering operation is performed, i.e., the switch is turned on, the metering system is initially operated by voltage such that the closing element closes at the initial starting position for metering operation.

[0018] Here, prior to each metering pulse, a closing element can be positioned at the valve seat of the valve or at the nozzle of the valve, and in the metering operation, it can be raised to a minimum from this initial starting position and then lowered again, so that the metering material can be ejected as appropriate, depending on the position and the duration of opening. In the jet method, the metering material is additionally ejected because, as mentioned above, the plunger functions as an ejection element and ejects the metering material when it moves toward the valve seat to close as an ejection element.

[0019] Regardless of the type of plunger function, it is often advantageous for the metering material to have sufficient viscosity, as this viscosity prevents it from leaking or flowing out of the valve on its own, even when the valve is open. Nevertheless, sometimes even low-viscosity metering materials cannot avoid metering.

[0020] In the metering operation, which closes in the initial starting position, whenever metering does not occur, for example, in a switched state where no current flows, or in the case of a malfunction or damage, the closing element is preferably automatically positioned on the so-called valve seat or sealing seat of the valve, thanks to the tension of a properly adjusted spring. This means that the valve is closed sufficiently tightly by the closing element positioned therein, and as a result, even very fluid, low-viscosity metering material cannot escape. Therefore, this metering operation is particularly suitable for fluid metering material, or when the metering material will be metered out of the valve by additional pressure, as described above.

[0021] Furthermore, particularly advantageous embodiments and further developments of the invention will become apparent from the dependent claims and the following description, and the individual features of the various exemplary embodiments or variants can also be combined into new exemplary embodiments or new exemplary variants.

[0022] Preferably, the transmission lever can extend transversely in the direction of extension of the piezo actuator and in a direction transverse to the direction of extension of the plunger device. This means that the transmission lever extends transversely in the direction of extension from the elongated plunger device to the elongated piezo actuator.

[0023] The directions of extension of the piezo actuator and the plunger device may preferably be substantially the same.

[0024] By definition, the term "transversely" preferably indicates "substantially perpendicular to a line assumed to be the length". In this regard, as long as the direction of extension of the plunger device and the direction of extension of the piezo actuator are the same, the term "transversely" is here preferably understood to mean "substantially perpendicular to the directions of extension of the two components". Thus, as long as the direction of extension of the piezo actuator and the direction of extension of the plunger device are slightly different or approaching, these components do not extend completely parallel, and the term "transversely" can also mean "from one component transversely to the other component", and thus, for example, "slightly inclined or at an angle slightly deviated from 90° by a few degrees".

[0025] Thus, particularly preferably, the transmission lever can extend substantially perpendicular to the direction of extension of the piezo actuator and the direction of extension of the plunger device.

[0026] The displacement of the piezo actuator or the pulse transmission of pulses from the piezo actuator to the plunger device via the transmission lever is maximized by a transmission lever that extends laterally, preferably substantially perpendicular to the extending direction of the piezo actuator and the extending direction of the plunger device. Thus, as will be described in more detail below, the piezo actuator can exert an "opening moment" on the plunger device or transmit force to the plunger device for metering in energized metering operation via the transmission lever (insofar as it relates to a metering system configuration in which the valve in the de-energized state is closed by the plunger device as defined), which results in the movement of the plunger device away from the valve, and therefore a kind of "lifting action". In addition, when larger, elongated components extend substantially in only two directions orthogonal to each other, the housing can be configured in a very compact manner, particularly preferably substantially in a rectangular parallelepiped shape, and thus projections or protrusions by components extending inclined thereto can be largely prevented.

[0027] As mentioned, In the piezo actuator, tension is applied to the housing via a spring arrangement through a transmission lever using a plunger device. ru. The spring arrangement means at least one spring element that applies or pre-tensions tension to the transmission lever directly or indirectly to the housing surrounding the metering system, such as a pre-tensioning spring, particularly a compression coil spring.

[0028] As already stated in European Patent Application Publication No. 1 414 080, this stipulates that the metering system is not relaxed when an external force is applied to the metering system, and therefore the components are held together in an appropriate manner.

[0029] The transmission lever is preferably fitted on the side of the shaft facing the piezo actuator in such a manner that it can be tilted to the inclined axis of the shaft. This means that the transmission lever is held between the shaft and the piezo actuator.

[0030] The shaft can also be secured, preferably, at the end of the lever bearing on the side facing away from the valve or on the upper side. This means that the shaft is mounted, for example, non-rotatably, and the transmission lever is tilted relative to the non-rotatable shaft.

[0031] Alternatively, for example, the trough could be recessed or formed within the transmission lever on the side of the lever facing away from the piezo actuator, and could be pressed, for example, in a non-rotatable manner to hold the shaft into the trough. The shaft would then rotate in the lateral opening in the lever bearing.

[0032] Basically, the transmission lever can have, for example, two substantially symmetrical lever arms, and therefore two lever arms of at least the same length, that is, it can be mounted substantially in the center around the inclination axis.

[0033] The transmission lever can preferably be mounted eccentrically and configured asymmetrically, that is, it can have a short lever arm and a lever arm that is relatively longer. Such a transmission lever will be described more precisely below with the help of a preferred exemplary embodiment.

[0034] With respect to a transmission lever having a short lever arm and a relatively longer lever arm, the transmission lever can be fitted in a tiltable manner, particularly preferably eccentrically, at the aforementioned end portion (to save space).

[0035] Here, in order to open the valve, the piezo actuator can preferably be located on a long lever arm, near the inclination axis, at the actuator engagement point, perpendicular to the inclination axis in the transmission lever, preferably in the form of a roller bearing. Thereafter, the transmission lever can be moved in the direction of an open valve position away from the valve, or away from the tight valve seat, while the piezo actuator is displaced during operation, together with a plunger device located on the long lever arm, further away from the inclination axis than the actuator engagement point closer to the inclination axis. The relative terms “near the inclination axis” and “away from the inclination axis” refer here to a point or position in the longitudinal direction of the transmission lever with respect to the inclination axis on which the transmission lever is tiltably mounted, respectively. The term “near the inclination axis” simply means, as appropriate, a position or point along the longitudinal or transverse extending direction of the transmission lever, where such point is located closer to the inclination axis than a point away from the inclination axis.

[0036] The plunger device can preferably be formed from at least two rod elements that are tensioned relative to each other. The term “tensioned relative to each other” means that a force acts on the rod elements that permanently presses them against each other, resulting in them being in a permanent pressing contact state.

[0037] Here, the plunger device may, particularly preferably, have a transmission element as a first rod element on the lever side. Hereafter, the transmission element preferably functions as a “connecting rod” type, as will become clearer, and is also called a “connecting rod” or “con rod”, and thus performs movement along a slightly circular path.

[0038] Furthermore, the plunger device may, particularly preferably, have a closing element as a second rod element on the valve side. As is customary in the art, the closing element will hereafter be referred to as the “valve plunger rod” or simply the “plunger”.

[0039] The combination of the above features ensures that the transmission element is in pressure contact with the closing element or the lever-side plunger head of the plunger. Therefore, the configuration ensures that the movement of the transmission lever, including both axial and lateral components, is not directly transmitted to the valve-side closing element of the plunger device, but only indirectly to the closing element via the lever-side transmission element. Thanks to the pure pressure contact, and also because the closing element can still be advantageously guided primarily axially, the lateral component is hardly transmitted to the closing element in the transmission of motion of the transmission element.

[0040] For example, in the non-energized state of the metering system or when no voltage is applied, in order to tightly seal the valve at the so-called valve seat or sealing seat in the valve by the tip of the plunger on the valve side of the closing element or plunger, the valve-side rod portion of the plunger device, and therefore the closing element, is capable of performing purely axial movement with as little lateral component as possible. This facilitates the ability of the closing element to be guided or pressed as straight and as accurately as possible into the valve seat, reducing the risk that adequate sealing of the valve may no longer be guaranteed, especially for low-viscosity metering materials.

[0041] Furthermore, dividing the plunger mechanism into two rod sections that are tensioned relative to each other helps characterize the movement of the connecting rod so that the transmission element that actually comes into direct contact with the transmission lever can minimize wear on potential friction points between the plunger mechanism and the transmission lever, which would exist in the guide that receives axial forces.

[0042] Therefore, in addition, the valve-side components that, according to experiments, suffer the most wear can be replaced individually or separately without requiring the metering system to be disassembled for this purpose, or without requiring the plunger device to be replaced as a whole.

[0043] There are various possibilities for the composition of a spring arrangement.

[0044] As mentioned, Spring arrangements are , The langer device has several springs or spring elements for spring tensioning. ru. It is possible, for example, to include a spring or spring element that presses the plunger device against the transmission lever on the valve side, i.e., on the side facing the valve in the installed state, or on the side of the transmission lever that faces away from the valve, so that these components are in pressure contact with each other. Additionally or alternatively, it is possible to include a spring that presses the plunger device to an open valve position located just above the valve seat in the de-energized state of the metering system, i.e., the plunger device does not close the valve of the fluid unit in the de-energized state. As already stated above, such a normally open mode of operation of the metering system exists when the metering material has, in any case, for example, a corresponding viscosity or high viscosity and therefore does not flow out on its own from the open valve opening under gravity.

[0045] However, the spring arrangement can also be configured such that the metering system has a closed valve in an unenergized switched state, i.e., the plunger device or the plunger of the plunger device is pressed against the valve seat. As mentioned, such a normally closed mode of operation of the metering system exists in the case of low-viscosity materials that would tend to flow out or spill out of the valve opened by gravity.

[0046] More preferably, the spring arrangement may optionally comprise at least one opening spring arrangement for opening the valve and at least one closing spring arrangement for closing the valve, wherein the closing spring arrangement has a larger spring constant or pretensioning force than the opening spring arrangement, for example, twice as large.

[0047] Such a spring arrangement results in the valve remaining closed when de-energized because the spring force of the closing spring is dominant over the opposing spring force of the opening spring. The valve begins to open automatically or inevitably simply from the point where the transmission lever, along with the opening spring, pulses from the piezo actuator to at least equalize the force of the closing spring. In other words, when the transmission lever presses the closing spring away from the valve, the opening spring automatically opens the valve.

[0048] A closing spring arrangement can, here, simply consist of a single closing spring having a larger or twice the spring constant and / or pretensioning force compared to an open spring arrangement (which may have only one open spring). However, instead of a closing spring having twice the spring constant and / or pretensioning force compared to an open spring, the spring arrangement may also, particularly preferably, consist of two closing springs acting in the same direction but in opposite directions to the open spring, for example, two substantially identically configured closing springs, each having half the spring constant and pretensioning rate with respect to a single closing spring (in a first-order approximation), but the same with respect to the other closing spring. In the following, a preferred variation will always be referred to as two closing springs (with half the spring constant and pretensioning force) instead of one closing spring (with twice the spring constant and pretensioning force). This is not intended to have a limiting effect insofar as at least two closing springs are always required hereafter. Basically, unless otherwise specified below, the two closing springs can always be replaced with the corresponding springs in different positions, where applicable. This is because, in a first-order approximation, a closing spring of twice the strength performs the same function as two closing springs of half the strength. The advantage of two springs compared to a single spring is that they can be used in a more variable way, particularly in various positions, as will be explained more precisely below.

[0049] Very preferably, the spring arrangement may comprise two closing springs that operate in the same direction but in the opposite direction to the opening spring, and the two closing springs having approximately the same spring constant and pretensioning force as the opening spring in a first-order approximation, so that the force of the closing springs is thus almost twice that of the opening spring.

[0050] In this regard, it can be said that the spring arrangement can basically be equipped with various types of springs, such as tension springs, wave springs, leaf springs, torsion springs, etc. Particularly preferably, the spring arrangement can be equipped with compression coil springs. Possible forms of such compression coil springs or compression springs that appear in particular are, for example, cylindrical, conical, barrel-shaped, and waist-shaped compression springs.

[0051] Preferably, the opening spring arrangement, or opening spring (hereinafter, the opening spring arrangement will also be referred to as the "opening spring" in a lesser form without loss of generality), is elastically fitted with the closing element within the housing, as already described above, so that a force acts on the closing element to move the closing element toward the open valve position.

[0052] Here, the closing spring can elastically tension the transmission element in the housing such that a reaction force at least somewhat greater than that of the opening spring acts on the transmission element to move the transmission element against the closing element, and therefore move the closing element in the direction of the closed valve position. As already mentioned above, the configuration of the elastically mounted plunger device makes it possible that components currently available for both normally open and normally closed metering systems (e.g., the plunger device and fluid unit) can be used.

[0053] As already described in European Patent Application Publication No. 1 414 080, the spring arrangement of the metering system may also include at least one compression coil spring, which is larger radially outward, and which surrounds, in a space-saving manner, at least one of the comparatively smaller closing compression coil springs already described. By function, this compression coil spring, also referred to hereafter as the “pretensioning spring,” makes it possible to pretension the transmission lever against the piezo actuator, on a long lever arm spaced apart from the housing and away from its tilt axis, and therefore further away from the tilt axis than the actuator engagement site on the same arm which is closer to the tilt axis. By pretensioning the piezo actuator, it is achieved that after displacement, the latter can be returned more quickly and completely back to its initial position.

[0054] In contrast to European Patent Application Publication No. 1 414 080, preferably, the transmission lever can be pretensioned or pretensioning can be set such that the valve is closed at the valve seat of the valve by at least the tip of the plunger of the valve-side plunger of the plunger device in which the plunger device is located, in the initial unenergized state of the metering system.

[0055] There are also various possibilities for further configurations of the plunger device.

[0056] The transmission element of a plunger device may preferably comprise two parts that can be connected to one another. These can be connected by press-fitting and / or mating. For example, these parts can be pressed against each other.

[0057] Alternatively or additionally, the above parts can be bonded together.

[0058] More preferably, the above-mentioned components may be thermally shrunk or connected by thermal shrinkage.

[0059] Particularly preferably, the transmission element may further comprise a rod portion as one part and a head sleeve portion as a further part.

[0060] Here, preferably, an elongated, particularly cylindrical, rod portion of the transmission element can be located or present on the valve side, i.e., at the end facing the valve in the installed state, and can extend from there to the head sleeve portion on the other side of the transmission lever. For example, the rod portion can extend substantially through, or strictly beyond, the transmission lever, away from the inclined axis of the long lever arm of the transmission lever.

[0061] Preferably, the rod portion may be guided with some play around it and extend through a through-opening or through-bore in the transmission lever, with some play around it.

[0062] Alternatively or additionally, the head sleeve portion may preferably have a flange on which the transmission lever is located or present on the flange, on the valve side, i.e., on the flange surface facing the valve in the installed state. Particularly preferably, the flange may be located approximately halfway along its longitudinal extension.

[0063] Dividing the transmission elements into several individual parts that are themselves of little complexity and are connected to one another makes their manufacture as a whole more beneficial and, in addition, much easier. As already mentioned, these parts can be easily connected to the connected components by, for example, a thermal press. In exemplary embodiments to be described further later, the transmission lever is capable of axially displacing a plunger device that is guided very precisely against the forces of two closing springs, and thus, for example, it is capable of being pressed upward, as a result the valve moves to the open valve position, automatically opening due to the reaction force of the closing springs, which the transmission lever temporarily overcomes or overcomes due to the force of the opening springs.

[0064] There are also favorable possibilities for the placement of the plunger device within the enclosure.

[0065] The rod portion of the transmission element is preferably guided axially parallel to the piezo actuator on the valve side within the first housing sleeve portion of the housing sleeve of the housing, with relatively little play around the radial direction. This means that the rod portion of the transmission element on the valve side near the transmission lever, i.e., in this case, in the area near below the transmission lever, can be guided axially, although it may move slightly radially and laterally with respect to the cylindrical rod portion within the housing sleeve. The rod portion therefore moves as straight as possible only axially, outward from the valve seat, outward from the valve, or inward from the valve seat, inward from the valve, without significant lateral movement.

[0066] In contrast, the head sleeve portion of the transmission element facing away from the valve can be guided with relatively wide radial play. This allows for slight lateral movement of the head sleeve portion, or movement along a circular path, through a contact point with the transmission lever away from the inclination axis, where, as already described many times, a pulse or some kind of "torque" is transmitted by a piezo actuator closer to the inclination axis. The head sleeve portion then acts like a kind of connecting rod, as will be described in more detail below.

[0067] In other words, the head sleeve portion on the other side of the transmission lever, and therefore in this case the upper side, as viewed from the valve, is almost completely unrestricted in its radial movement and, therefore, can move almost freely to its maximum extent, at least insofar as it can move within the range of possible movement of the rod portion that is tightly axially guided to it on the valve side, and therefore in this case the lower side. This means that in any case it is limited to a very small range of lateral movement or movement by the length of the rod portion. This is because if the head sleeve portion is moved too far laterally, the rod portion will come into direct contact with its axial guide around nearby on the lower side, and therefore prevent further lateral movement or displacement (or radial movement) of the head sleeve portion.

[0068] Preferably, one of the closing springs of the spring arrangement, in particular, a small compression coil spring surrounded by a large compression coil spring, may be located or present in the head sleeve portion on the flange side facing away from the valve.

[0069] The transmission element or the head sleeve portion of the transmission element can therefore be tensioned between the housing and the closing element without directly contacting the lever mentioned above. In addition, this arrangement saves space and therefore does not unnecessarily lengthen the plunger device of the metering system, when the closing spring is housed internally, and therefore in an area where the pre-tensioning spring of the piezo lever system is not used.

[0070] The flange of the head sleeve portion may have a hemispherical projection on the valve-facing side for low-wear interlocking between the transmission lever and the plunger device on the valve side in the intended installation configuration. These may form bearings together with a particularly preferably recessed corresponding spherical cap formed for this purpose on the transmission lever.

[0071] The surface of the spherical shell in the spherical cap undergoes a slight, especially frictionless, rolling motion, so the bearing is also called a “roller bearing,” and thereby a nearly frictionless transition is formed between the slight circular path movement of the head sleeve portion or the movement of the connecting rod and the axial movement of the rod portion.

[0072] Particularly preferable, the spherical shell in the flange of the head sleeve can be configured as a spherical cap in which a sphere is pressed into it, resulting in a hemispherical recess. This simplifies manufacturing because it eliminates the need to form the hemispherical protruding spherical shell, which is one of the components.

[0073] Most preferably, the flange of the head sleeve portion may be provided with a bearing block behind the contact point where the closing spring is located. The bearing block may further protrude from the round flange, for example, in the form of a rectangular parallelepiped (a block-shaped cordal quadrilateral), toward the transmission lever and away from the closing spring. Such an additional bearing block on the round flange has the advantage that it provides space for forming or retracting a spherical cap therein. To receive the two spherical cap recesses or spherical caps of the transmission lever in a low-wear manner, the bearing surface of the bearing block may be provided with a hemispherical recessed spherical cap within itself, in which a sphere is pressed, and the spherical caps of the transmission lever can roll within the hemispherical recessed spherical cap.

[0074] The “interlocking” between the spherical cap in the transmission lever via a pressed ball inside the head sleeve, manufactured in this way, is “releasing” only when the valve is closed, when the plunger or closing element is slightly raised from the transmission lever through the nozzle or valve insertion in the valve.

[0075] There are also various possibilities for further configurations of the metering system.

[0076] Preferably, the first permanent magnet can be attached to the plunger device, preferably to the head sleeve portion of the transmission element. The permanent magnet can be attached, for example, to the front end of the plunger device, away from the valve.

[0077] Particularly preferably, the permanent magnet can therefore be fastened, more precisely, to the end of the plunger device on the head sleeve portion of the plunger device, or to the end of the head sleeve portion of the plunger device facing away from the transmission lever, in the intended installation configuration.

[0078] Here, preferably, the Hall sensor can be positioned in the housing opposite the permanent magnet and spaced apart by a gap. Conventionally, this sensor can be positioned, for example, on a board for controlling a metering system located above the front end of the head sleeve portion of a plunger device.

[0079] The permanent magnet and Hall sensor described above allow the position of the plunger device relative to the valve or nozzle to be measured and, at that time, adjusted accordingly. Here, for example, a standardization table can display the correlation between the voltage change of the Hall sensor and the distance change present. First, before adjusting the precise position of the plunger device relative to the nozzle, the head nozzle portion of the transmission element of the plunger device is positioned on or above the transmission lever, in this case the plunger tip of the plunger does not directly contact it in the normally closed valve position and does not yet close the nozzle or valve. To adjust the proper position of the plunger relative to the nozzle, the nozzle is moved in the direction of the plunger until a predetermined change is detected by the permanent magnet and Hall sensor described above, thus resulting in a predetermined lift of the head sleeve portion, in particular the spherical shell, from the transmission lever, from the spherical cap of the transmission lever. For this purpose, the distance between the nozzle and the plunger tip is reduced by rotating the adjustment nut until a desired voltage change can be detected via the Hall sensor. This desired position can then be continuously monitored during operation.

[0080] More precisely, at the beginning of the adjusting process or “adjustment process,” the distance between the nozzle insert and the plunger is generated by a connecting nut or (nozzle) adjustment nut, which is rotated to the lowest adjustable position, as will be further described later by exemplary embodiments (the maximum distance between the nozzle insert and the plunger). This adjusting routine or “adjustment routine” is initiated, and the above distance is first reduced, and finally, the plunger is raised through the nozzle insert until the display in the control unit indicates that it has reached the desired position (slightly raised from the lever above).

[0081] As a result, during operation, it is possible to constantly monitor whether the component of the lever movement changes without plunger entrainment (a gap created by a slight lift during the adjusting or tuning process), and / or whether the Hall sensor voltage changes in the closed state, and / or how large the overall change in the Hall sensor signal is relative to the desired or expected plunger movement. Here, the control signal can also be configured, if necessary, so that the above movement remains equal and therefore stable even in the case of wear. Thus, the necessary user engagement during operation can be prevented for as long as possible, which, for example, increases the productivity of the machine and reduces maintenance time.

[0082] Preferably, here, for example, a smaller second permanent magnet can be positioned on the side of the Hall sensor facing away from the first permanent magnet.

[0083] Preferably, the second permanent magnet may have a magnetic field opposite to that of the first permanent magnet.

[0084] Therefore, the measurement range of a Hall sensor, which is always divided symmetrically around a zero point, can be advantageously shifted so that a larger, fuller measurement range is available and thereby has greater sensitivity. This is because a Hall sensor can no longer measure simply in the positive range or in the negative range. Rather, its measurement range is shifted, and thus increased, at least partially, preferably completely, into the negative range, or, depending on the polarity of the magnetic field, into the positive range.

[0085] Alternatively or additionally, the surrounding area around the Hall sensor can be magnetically protected by a shield, particularly preferably including a second permanent magnet, but at least on the side facing away from the first permanent magnet.

[0086] The side facing away from the first permanent magnet means that the shield can be advantageously opened toward the first permanent magnet on at least one side, and as a result, the head sleeve portion containing the first permanent magnet can be moved into the shield at least on this side, and the influence of any external magnetic fields that may enter on the other side can be blocked. For this purpose, the shield can be configured, for example, in a substantially rectangular parallelepiped shape, or using a rectangular parallelepiped housing.

[0087] Alternatively or additionally, the shield may consist of a rectangular component, a flexible magnetic lever bearing, and / or a flexible magnetic component inserted into the lever bearing in the direction of the valve. In particular, the flexible magnetic component inserted into the lever bearing exists when the lever bearing is made of a more advantageous stable material, such as aluminum, which does not act in a manner that provides sufficient magnetic protection on its own but provides the necessary stability.

[0088] Advantageously, as already mentioned, the upper region above the board and the frame region surrounding the piezo actuator can be made from non-magnetic materials to allow for a more advantageous and lighter design. Generally, measurement errors can be practically prevented by the shielding, or interference factors that could affect the measured magnetic field are minimized.

[0089] As already mentioned above, in the housing sleeve, the plunger device is guided at least internally within the section, but preferably the housing sleeve can be adjusted externally to a predetermined location by a spring that can be tensioned by a nut to the housing around the metering system in order to adjust the distance between the valve and the closing element (commonly also called the “nozzle-plunger distance”). This distance can be adjusted very easily by the customer using this nut, and can also be adjusted to a very precise value, for example, by manual measurement using a permanent magnet and a Hall sensor as described above, in the simplest case.

[0090] Preferably, the transmission lever can be configured and positioned such that, at the de-energized starting position of the piezo actuator, tension is applied to the plunger device against the piezo actuator via the transmission lever, such that the actuator engagement point of the piezo actuator near the tilt axis of the transmission lever is located on a line or plane including the roller bearing surface of the shaft of the tilt axis relating to the transmission lever and the spherical shell of the flange of the head sleeve portion of the spherical cap away from the tilt axis of the transmission lever.

[0091] Therefore, the piezo actuator in the starting position has the advantage of engaging at the height of the tilt axis and at the height of the contact point with respect to the plunger device of the transmission lever.

[0092] For example, on the one hand, the piezo actuator can be firmly fixed and supported on the valve side via a surface contact. On the other hand, tension can be applied to it by a linear actuator engagement point parallel to the surface contact on the lever side near the inclined axis on the long lever arm of the transmission lever.

[0093] Preferably, the closure element, especially preferably together with the fluid unit, can be advantageously installed in the metering system in a way that makes it replaceable and removable, most especially without the use of tools, directly by the customer. This means that the closure element can be, for example, simply coupled to or accessible to the transmission element under pressure, and as a result, it can be changed or replaced very easily and quickly, especially without the use of tools, by the customer. Installing the closure element in such a replaceable manner in the metering system is therefore particularly advantageous because it improves the lifespan of the metering system as a whole, since it is the component of the metering system that is exposed to the greatest wear during the operation of the metering system.

[0094] The present invention will be described again in more detail below, utilizing exemplary embodiments and with reference to the accompanying drawings. Here, the same components are given the same reference numerals in the various figures. The figures are generally to be understood as schematic illustrations only, and not to scale. [Brief explanation of the drawing]

[0095] [Figure 1] A longitudinal cross-section of the partially opened, illustrated housing, as seen from inside, in an exemplary embodiment of the metering system according to the present invention, in which the fluid unit is not connected and the plunger has been removed. [Figure 2]A schematic side view of an exemplary embodiment of Figure 1, which has the most essential components for a metering mechanism (without a housing for clarity), but with a plunger attached and a fluid unit connected. [Modes for carrying out the invention]

[0096] These figures illustrate exemplary embodiments of a metering system 1 according to the present invention. The main components of this metering system 1 include a housing 2 having a piezo actuator 10 located therein, a fluid unit 15 having a valve 16 (see Figure 2), a plunger device 40 for closing the valve 16, and a transmission lever 20 or lever 20 for connecting the piezo actuator 10 to the plunger device 40.

[0097] Generally, the housing 2 of the metering system 1 can be described as having a roughly rectangular parallelepiped shape. Figure 1 shows a longitudinal cross-section of the metering system 1 without the fluid unit (not shown in Figure 1) connected. Figure 2 shows, in particular, how and where the fluid unit 15 of the metering system 1 is connected to the rest of the metering system 1.

[0098] In this regard, at the lower corner (here on the right), the housing 2 has a connection point at the bottom for the elongated closing element 51 or plunger 51 of the plunger device 40 and for the fluid unit 15 having the valve 16. The closing element 51 or plunger 51 is either a part of the fluid unit 15 or is mounted within the latter and can be replaced together when the fluid unit 15 is replaced.

[0099] As can be seen in Figure 2, in the intended connected state, the plunger 16 is positioned in the valve 16 at the so-called valve seat or sealing seat. In this position, it closes the valve 16 as needed, and as a result, the metering material cannot unintentionally flow out or escape from the valve 16. In this regard, the operating metering system 1 is generally used primarily in the orientation shown in Figure 1, that is, metering on the workpiece is mostly performed using gravity and therefore in the metering direction DR, so for example, downward from the lever 20 towards the valve 16. It is mentioned again that relative directional information such as “top,” “bottom,” “up,” “down,” “upper side,” “lower side,” “lateral or left / right,” “horizontal,” “vertical,” “front,” “back,” etc., is hereby referred to arbitrarily by the examples in the figures, as is also mentioned in the whole document.

[0100] Several cables or lines exit the enclosure 2 at the upper corner on the opposite side (in this case, the left side). Through these, the metering system can be connected to a higher-level control unit (not shown here) for control, current supply, etc., the latter can likewise be connected to the higher-level metering system.

[0101] Within the housing 2, the cylindrically encapsulated piezo actuator 10 is located in the lower half of the center, as will be described later. The latter is mounted at its rear end downward on a flat surface contact portion 5 of the housing 2, which has a planar or flat support surface 14, and is electrically connected via a through contact bore. Through this mounting, losses in the mounting area can be minimized. At the opposite upper end, the piezo actuator 10 has a trapezoidal actuator front portion 11 that extends to a lever 20 located above it, and this actuator front portion forms a roller bearing 24 on a cylinder pin 24z that extends laterally or horizontally through the lever 20, sinking into the lever 20 and positioning or engaging with the actuator engagement point 24. The cylinder pin 24z is firmly pressed into the lever 20, and as a result, the piezo actuator 10, having its actuator front portion 11, is configured to be jaw-shaped or concave relative to the cylindrical outer surface of the cylinder pin 24z, and when it is stretched upward or compressed downward in the opposite direction, the piezo actuator 10 can roll slightly laterally, and therefore to the right or left, on the cylinder pin 24z, so as a pulse is applied to the lever 20 by applying a voltage.

[0102] Here, the piezo actuator 10 itself is a sealed and encapsulated piezo actuator 10, that is, it comprises a piezo stack enclosed away from the line guided through the “wavy” encapsulation 12 of the piezo actuator 10, the encapsulation 12 being enclosed by the housing 2 in a hollow cylindrical shape with some play. An annular ring seal 13 around the upper side of the piezo actuator 10 below the actuator front portion 11 seals the space between the encapsulation 12 and the housing 2, thus forming an intermediate space around the encapsulation 12, in which a cooling fluid can circulate to cool the piezo actuator 10 in operation around the encapsulation 12. For this purpose, the cooling fluid is advantageously introduced into the intermediate space in a continuously cold state on one side and discharged again in a warm state on the other side (not shown here), so that the piezo actuator 10 does not exceed a certain maximum operating temperature in either case.

[0103] As already mentioned, the lever 20 is located above the piezo actuator 10. The lever is mounted within the housing 2 via a cylindrical shaft 4 that extends laterally (into or out of the plane of the drawing) relative to the lever 20, so as to be tiltable around the shaft 4 or the tilt axis R, which represents or embodies the tilt axis R.

[0104] For this purpose, the shaft 4 is securely and stably fastened or mounted to the lever bearing 3, or to the lever bearing portion of the housing 2, respectively, with the lever bearing 3 surrounding the lever 20. The lever 20 is pressed or tensioned from below against the shaft 4 by the pretensioning spring 67 of the spring arrangement 60 and the piezo actuator 10. Thus, in the starting position, it is aligned approximately horizontally.

[0105] A very short lever arm 21 extends from an eccentric or off-center position on the shaft 4 or inclined axis R in the longitudinal extension of the lever 20 (here to the left in the longitudinal section in Figure 1), and a longer lever arm 23 extends in the opposite direction (here to the right). The short lever arm 21 serves only as a bearing 22 or trough for the shaft 4, and as a result the eccentrically positioned shaft 4 is located, so to speak, at approximately one end of the lever 20, but cannot slip on the side of the short lever arm 21 on the lever 20.

[0106] The long lever arm 23 has an actuator engagement point 24 of the piezo actuator 10 near the tilt axis, and therefore near the position of the shaft 4, and a plunger contact point 25 away from the tilt axis, and therefore at the end portion of the lever arm 23. At the plunger contact point 25, the lever 20 surrounds the plunger device 40—a kind of "shovel" having a "hole" 28 or through-opening 28 on the shovel surface—on the inner edge of the hole 28, in its extending direction E 20 It can be received or lifted almost perpendicular to it.

[0107] The pretensioning spring 67, which is a large compression coil spring 67 having a larger inner diameter than the hole 28 as described above, means pretensioning the lever 20 to the piezo actuator 10 around the hole 28 on the upper side of the shovel surface of the lever 20, along the edge 27 of the hole 28, or at the pretensioning contact point 27.

[0108] The plunger device 40 extends in the direction E of the piezo actuator 10 in the housing 2. 10 Approximately parallel to the extension direction E 40 In the direction of extension of the lever 20, very close to the piezo actuator 10, through the hole 28 of the lever 20 (E 20Since they extend (approximately perpendicular to E), the illustrated arrangement is particularly compact. That is, the piezo actuator 10 and the plunger device 40 are therefore in the same extending direction E 10 , E 40 They are substantially arranged vertically within the housing 2, adjacent to each other, and particularly compactly, and are connected to each other via relatively short levers 20, and thus simply spaced a short distance apart from each other.

[0109] At the plunger contact point 25, the lever 20 engages directly with the plunger device 40 from below and lifts the plunger device 40 (from below in the opening operation of the valve 16, as will be further described below), the plunger contact point 25 has a surface having two recessed spherical caps 26, the two spherical caps 26 receiving the corresponding spherical shell 49 of the plunger device 40 in an interlocked manner, as will also be further described below.

[0110] The plunger device 40 itself consists of two rod elements 41 and 51, and when the metering system 1 is ready for operation, tension is applied to the two rod elements 41 and 51 relative to each other by the spring arrangement 60 already described. In this ready-to-operate state, the fluid unit 15 is connected to the housing 2 of the metering system, as shown in Figure 2.

[0111] The first rod element 41 (here, the upper) of the plunger device 40, or transmission element 41, then consists of two separately manufactured parts 42, 45: an elongated rod portion 42 having a rod with a cylindrical outer surface, and an elongated head sleeve portion 45 having a hollow cylindrical cylinder body and a wider head. The two parts 42, 45 are pressed against each other for mounting, i.e., the rod portion 42 is fixed at its end portion inside the hollow cylindrical head sleeve portion 45 by a customized fixing method, i.e., by thermal shrinkage.

[0112] For mating connection with the head sleeve portion 45, the rod portion 42 has annular grooves or flutes 43 projecting radially outward on the outer surface of the end portion that is introduced or inserted into the head sleeve portion 45.

[0113] Correspondingly, the head sleeve portion 45 of the transmission element 41 has an annular spring 46 projecting radially inward, the spring 46 engaging with the annular groove 43 or flute 43 in a manner of at least slight mating when the two parts 42, 45 are connected. The annular grooves 43 and the annular spring 46 of the two parts 42, 45 can also, alternatively, be associated with corresponding inner and outer threads, which can be screwed into each other to connect the two parts 42, 45 in a mating manner.

[0114] The head of the head sleeve portion 45 forms a flange 47 that is wider than the rest of the head sleeve portion 45. The flange 47 has two different surfaces 47a and 47b when viewed axially from the head sleeve portion 45. On the valve side (when viewed axially), it has a first flange surface 47a formed by a rectangular parallelepiped bearing block 48. Facing away from the valve, it has a second flange surface 47b that is circular and disc-shaped.

[0115] One of the closing springs 64b or smaller compression coil springs 64b (further described below) of the spring arrangement 60 for closing the valve 16 is located on the rounded flange surface 47b facing away from the valve. The compression coil springs 64b encircle the cylinder body inside the head sleeve portion 45 in an annular manner.

[0116] On the rear side, i.e., on the valve side, the bearing block 48 protrudes flange-like, in the form of a “cordal rectangle,” with respect to the circular disc-shaped flange surface 47b, from the second flange surface 47b facing away from the valve. It has two spherical shells 49 (already described above) that protrude hemispherically in the direction of the lever 20. These roll on the corresponding spherical caps 26 (similarly described above) that are formed or recessed into the lever 20 at the plunger contact point 25 during operation. The head sleeve portion 45 of the plunger device 40 is, so to speak, interlocked with the lever 20, forming a low-friction point of contact.

[0117] The second rod element 51 (here, the lower part in Figure 2) or closing element 51 of the plunger device 40, also hereafter abbreviated as “plunger 51”, is integrally formed. It has an elongated cylindrical body or shank, which is formed having a plunger tip 52 at the lower end (the end facing the valve 16 in the intended installation) and a plunger head 53 at the opposite upper end. The plunger head 53 relates to an annular flange, and therefore an annular spread, or a ring having a wider outer diameter than the rest of the body or shank of the plunger 51. The plunger tip 52 here relates, for example, to the rounded front portion of the plunger 51. However, the plunger 51 may also relate to a so-called “valve pushrod”, such as one specifically described in German Patent Application Publication No. 10 2020 121 777, which is different from the one illustrated herein. In this regard, the details are incorporated herein.

[0118] On the upper side, that is, on the lever side of the plunger 51, the transmission element 41 described above is located on the plunger head 53.

[0119] In this regard, as can be easily seen in Figure 1, the housing 2 has a slightly elliptical discharge opening 2d in the region of the plunger head 53 of the plunger 51, or almost at the height of the plunger head 53 of the plunger 51. In the event of leakage of the metering material to be metered, this means that it is impossible for the metering material to reach or be pressed into the drive region of the metering system 1 located above the plunger 51 from the nozzle chamber of the fluid unit 15 located below it in the region of the plunger tip 53, and that, at a point favorably selected by the metering system 1, it is possible for it to flow out of the metering system 1 from this discharge opening 2d. At the same time, the size of the discharge opening 2d allows for a simple, and therefore easy, visible optical check of this region.

[0120] As already partially described, the plunger device 40 is elastically attached to itself by the spring arrangement 60, or tension is applied to the plunger device 40 relative to one another. For this purpose, the spring arrangement 60 has, on the one hand, three smaller compression coil springs 61, 64a, and 64b which are substantially identical in structure and substantially the same outer diameter, with the compression coil springs 64a and 64b forming the closed spring arrangement 64a and 64b, and the compression coil spring 61 forming the open spring arrangement 61.

[0121] The compression coil springs 64a, 64b or two of the closing springs 64a, 64b are arranged such that their elastic force pushes the plunger device 40 toward the valve 16, by ultimately pressing the plunger 51 of the plunger device 40 toward the closed valve position toward the so-called valve seat in order to close the valve 16.

[0122] The lower of the two closing springs 64a and 64b, the closing spring 64a, is positioned above the plunger head 53 of the plunger 51 within the range of the second housing sleeve portion 8 of the housing sleeve 6 of the housing 2, and acts indirectly on the plunger head 53 of the plunger 51 from above via the guide sleeve 8f. Here, the closing spring 64a is supported from above against the limit portion 66a or edge 66a of the first housing sleeve portion 7 of the housing sleeve 6, which surrounds the shank or cylindrical body of the rod portion 42 of the transmission element 41 with some play and is located in close proximity with relatively little play around the shank of the rod portion 42, and the plunger device 40 is mounted within the housing sleeve.

[0123] The transmission element 41 is additionally pressed downward against the closing element 51 in the direction of the valve 16 by the upper closing spring 64b of the two closing springs 64a, 64b, the closing spring 64b is actually mounted above the flange 47 of the head sleeve portion 45 and above it is supported by portion 66b of the housing 2.

[0124] The third remaining (smaller) compression coil spring 61 or release spring 61 is positioned directly below the plunger head 53 of the plunger 51 and is pressed against the plunger head 53 by being supported at its lower end by a guide sleeve 63 that guides the plunger 51 axially when it is substantially connected to the rest of the metering system 1 together with the fluid unit 15 and the valve 16, as shown in Figure 2.

[0125] Therefore, overall, the two compression coil springs 64a and 64b press downwards, and the one compression coil spring 61 presses upwards, and as a result, the valve 16 is simply closed by the imbalance of forces, normally, i.e., when the metering system 1 is not energized.

[0126] When the operating lever 20, at that moment, presses the head sleeve portion 45 by the pulse of the piezo actuator 10, and moves the latter together with the rod portion 42 away from the valve 16 against the pressure of the closing springs 64a and 64b of the spring arrangement 60, it frees up the plunger 51 located below it in the closed valve seat. Here, through the elastic force of the closing springs 64a and 64b borne by the lever 20, there is temporarily no elastic force, or at least a smaller elastic force, against the opening spring 61, and as a result the opening spring 61 can push the plunger 51 up from the valve seat to the open valve position.

[0127] In addition to the spring arrangement 60, the metering system 1 also has a connecting spring 70. For example, when a fluid unit 15 having a desired valve 16 and a suitable plunger 51 (which may be part of the fluid unit 15 as described) is attached to the rest of the metering system 1, this helps in the feasibility of manual adjustment of the nozzle-plunger distance by the customer. For this purpose, in order to connect the fluid unit 15 to the rest of the metering system 1, the metering system 1 has a connecting nut 18 in the fluid unit 15 that can be screwed into the threads 9 in the fluid unit 15 or in the housing sleeve 6 of the housing 2. The connecting nut 18 can here be tightened against the elastic force of the connecting spring 70, and thus the nozzle-plunger distance can be adjusted more precisely. For this purpose, the connecting spring 70 has an inner diameter that is larger than the outer diameter of the first housing sleeve portion 7 and smaller than the outer diameter of the second housing sleeve portion 8, and in particular, an inner diameter that is approximately the same in size. The connecting spring 70 is located above the second housing sleeve portion 8 and above the connecting nut 18. Thus, it fits in and surrounds the first housing sleeve portion 7 and rests on the second housing sleeve portion 8 below in the direction of the valve 15. At the connecting portion of the connecting nut 18 above the connecting spring 70, it is sealed at two points, above and below, by two ring seals 19, so that fluids such as metering material cannot enter the housing components, and therefore, in particular, the frame that surrounds or receives the piezo actuator above it.

[0128] Furthermore, the metering system 1 also includes a fluid positioning unit 17 for positioning the fluid unit 15, the fluid positioning unit 17 being selectively heatable by corresponding control. This helps to heat the metering material, the fluid unit 15 having a valve 16, and / or the plunger 51 in the valve 16.

[0129] A magnetic shield 80 is positioned as a component of the housing 2 of the metering system 1 at the opposite upper end, above the plunger device 40 which is tensioned relative to each other by a spring arrangement 60. The magnetic shield 80 magnetically protects a Hall sensor arrangement, which has a first permanent magnet 81, a Hall sensor 82 spaced therefrom by a gap 84, and a second permanent magnet 83 above the first permanent magnet 81, outward, and particularly upward.

[0130] Furthermore, to magnetically protect the Hall sensor arrangement downwards, the portion of the housing 2 in the area of ​​the lever bearing 3 serves as an additional magnetic shield below the magnetic shield 80. Overall, the Hall sensor arrangement is therefore protected from external influences, and as a result, the Hall sensor can take measurements as accurately as possible without disturbance. This is because the Hall sensor helps to adjust the plunger-nozzle distance very precisely and can be monitored as a kind of "feedback system" during operation. Thus, for example, when the measured value is outside a predetermined target range, and operator intervention is required, the plunger movement during operation can be made correlated with the control voltage, and if applicable, the control voltage can be readjusted or a warning message can be generated. This is achieved by the distance between the Hall sensor 82 and the first permanent magnet 81, which is inserted into the upper sleeve end of the head sleeve portion 45 as a small rod-shaped permanent magnet 81 and detected by the Hall sensor 82 in the form of absolute magnetic field measurement. When a fixed value is measured, an ideal desired distance or gap 84 exists. Therefore, the plunger 51 is positioned at the other end of the plunger device 40 at a desired position, and thus at a desired plunger-nozzle distance with respect to the valve 16 or the nozzle 16. The second permanent magnet 83 is fixed above the Hall sensor 82, on the side of the Hall sensor 82 facing away from the first permanent magnet 81, and is positioned so that its magnetic field acts opposite to that of the first permanent magnet, and the second permanent magnet 83 helps to shift the magnetic field so that the measuring range of the Hall sensor 82 is fully available. This means that the measuring range of the Hall sensor 82, which is normally divided into positive and negative ranges, is shifted as completely as possible towards the positive or negative range in order to increase the sensitivity of the Hall sensor 82.

[0131] Finally, it should be noted once again that the above-described apparatus is merely representative of exemplary embodiments and can be modified in various ways without departing from the scope of the invention by those skilled in the art. For example, several metering systems can be arranged in the metering system. Furthermore, the use of the indefinite article "ein" or "eine" does not exclude the possibility that there may be multiple such features. [Explanation of Symbols]

[0132] 1. Metering System 2 cabinets 2d discharge opening 3. Lever bearings of the housing 4 shafts 5 Surface contact portion of the housing for the piezo actuator 6 Housing Sleeves 7. First housing sleeve section 8. Second housing sleeve section 8f Guide sleeve in the second housing sleeve section for guiding the closing spring 9 screw threads 10 Piezo actuators 11. Front part of the piezo actuator 12. Encapsulation 13 Ring seals 14 Support surface 15 Fluid Units 16 valves / nozzles 17 Fluid positioning unit 18. Connecting nuts for fluid units 19. Ring seal for connecting nuts 20 Transmission levers / levers 21 Short lever arm 22 Bearings for Shafts 23 Long lever arm 24 Actuator engagement point near the tilt axis / roller bearing 24z Cylinder pin near actuator engagement point 25 Plunger contact point away from the tilt axis 26 Spherical caps 27. Contact point / plate-shaped portion of the transmission lever's pretensioning spring. 28 Hole / through opening for the rod portion of the transmission lever 40 Plunger device 41 First rod element / transmission element 42. Rod section of transmission element 43 Annular groove on the rod section 45 Head sleeve section of the transmission element 46. ​​Annular spring on the head sleeve 47 Flange of the head sleeve 47a First flange surface, valve side 47b Second flange surface 48 Bearing Block 49 Spherical shell 51 Second rod element / closing element / plunger 52 Plunger tip of plunger / closing element of plunger device 53 Plunger Head 60 Spring Arrangements 61 Open spring arrangement / Open spring / Compression coil spring 63 Guide sleeve for closing element 64a, b Closure spring arrangement / Closure spring / Compression coil spring 66a Restrictions / Edges of the enclosure 66b Part of the enclosure 67 Pretensioning spring / Compression coil spring 70 Linked Springs 80 Shield 81 First permanent magnet 82 Hall Sensors / Hall Probes 83. Second permanent magnet 84 Gap DR Metering Direction / Direction from Transmission Lever to Valve E10 Extension direction of the piezoelectric actuator E 20 Extension direction of the transmission lever / longitudinal direction of the lever arm E 40 Extension direction of the plunger device S Q Second symmetry axis of the symmetry plane of the actuator Inclined axis passing through the R shaft

Claims

1. Metering system (1), The metering system (1) is The enclosure (2) and A piezo actuator (10) is located within it, A fluid unit (15) having a valve (16), A plunger device (40) for closing the valve (16), A transmission lever (20) for connecting the piezo actuator (10) to a plunger device (40), It has, The piezo actuator (10) is arranged within the housing (2) adjacent to the plunger device (40), and is substantially parallel to it. The piezo actuator (10) extends away from the transmission lever (20) in a direction substantially toward the valve (16), The piezo actuator (10) is subjected to tension on the housing (2) via the plunger device (40) and the transmission lever (20) by a spring arrangement (60). The spring arrangement (60) has a plurality of springs (61, 64a, 64b, 67) for spring tensioning of the plunger device (40). Metering system (1).

2. The transmission lever (20) is in the extending direction (E) of the piezo actuator (10). 10 ) and the extending direction (E) of the plunger device (40) 40 ) extends laterally to It is The metering system according to claim 1.

3. The plunger device (40) is formed from at least two rod elements (41, 51) that are tensioned relative to each other. The metering system according to claim 1.

4. The plunger device (40) comprises a transmission element (41) as a first rod element (41) on the lever side and a closing element (51) as a second rod element (51) on the valve side. The metering system according to claim 3.

5. The metering system according to claim 1, wherein the spring arrangement (60) comprises a plurality of compression coil springs (61, 64a, 64b, 67) for spring tensioning the plunger device (40), and / or an opening spring arrangement (61) for opening the valve (16), and a closing spring arrangement (64a, 64b) for closing the valve (16), having a greater spring constant and / or pre-tensioning force than the opening spring arrangement (61).

6. The metering system according to claim 5, wherein the closing spring arrangement (64a, 64b) has at least two closing springs (64a, 64b) that operate in the same direction, opposite to the opening spring arrangement (61).

7. The opening spring arrangement (61) is elastically fitted to the closing element (51) within the housing (2) such that a force acts on the closing element (51) to move the closing element (51) in the direction of the opening valve position. The closing spring arrangement (64a, 64b) elastically tensions the transmission element (41) within the housing (2) such that a reaction force acts on the transmission element (41) in order to move the transmission element (41) against the closing element (51), and therefore move the closing element (51) in the direction of the closed valve position. The metering system according to claim 5.

8. The transmission element (41) has two parts (42, 45) that can be connected to each other. The metering system according to claim 4.

9. The two components (42, 45) of the transmission element (41) that can be connected to each other are the rod portion (42) and the head sleeve portion (45). and / or, The head sleeve portion (45) has a flange (47) on which the transmission lever (20) is located on the valve side. The metering system according to claim 8.

10. The elongated rod portion (42) of the transmission element (41) is located on the valve side of the closing element (51) and extends from there to the head sleeve portion (45) on the other side of the transmission lever (20). The metering system according to claim 9.

11. The elongated rod portion (42) extends from the closing element (51) through the through-opening (28) in the transmission lever (20) to the head sleeve portion (45) on the other side of the transmission lever (20). The metering system according to claim 10.

12. The rod portion (42) of the transmission element (41) is guided axially within the first housing sleeve portion (7) of the housing sleeve (6) of the housing (2), parallel to the piezo actuator (10) on the valve side, with relatively narrow play around the radial direction. The head sleeve portion (45) of the transmission element (41), which faces away from the valve, is guided with relatively wide play around the radial direction. The metering system according to claim 9.

13. One of the closing springs (64b) of the spring arrangement (60) is located on the head sleeve portion (45) on the flange surface (47b) of the flange (47) facing away from the valve, The metering system according to claim 9.

14. The flange (47) of the head sleeve portion (45) has a spherical shell (49) that protrudes hemispherically on the valve side, and the spherical shell (49), together with the corresponding spherical cap (26), forms a bearing (26, 49), and the spherical cap (26) is formed for this purpose on the transmission lever (20). The metering system according to claim 9.

15. The first permanent magnet (81) is attached to the plunger device (40), Within the housing (2), the Hall sensor (82) is positioned opposite the permanent magnet (81) and separated by a gap (84). The metering system according to claim 1.

16. The first permanent magnet (81) is attached to the head sleeve portion (45) of the transmission element (41). The metering system according to claim 15.

17. A second permanent magnet (83) is positioned on the side of the Hall sensor (82) that faces away from the first permanent magnet (81), and the second permanent magnet (83) has a magnetic field opposite to that of the first permanent magnet (81), and / or The surrounding area around the Hall sensor (82) is magnetically protected by the shield (80) at least on the side facing away from the first permanent magnet (81). The metering system according to claim 15.

18. To adjust the distance between the valve (16) and the closing element (51), the housing sleeve (6) is mounted in an adjustable position relative to the housing (2) around the metering system (1). The metering system according to claim 12.

19. The transmission lever (20) is tiltably fitted onto an inclined shaft (R) in the form of a shaft (4) on the side facing the piezo actuator (10), and the shaft (4) is secured to the end side of the lever bearing (3). The piezo actuator (10) for opening the valve (16) is in the form of a roller bearing and is positioned at the actuator engagement point (24) perpendicular to the inclination axis (R) of the transmission lever (20) and close to the inclination axis. The metering system according to claim 1.

20. The transmission lever (20) is configured and positioned such that, at the de-energized start position of the piezo actuator (10), tension is applied to the plunger device (40) via the transmission lever (20) from the piezo actuator (10), such that the actuator engagement point (24) of the piezo actuator (10) on the transmission lever (20) lies on the line between the roller bearing surface of the shaft (4) on the inclined axis (R) relative to the transmission lever (20) and the spherical shell (49) on the flange (47) of the head sleeve portion (45) of the spherical cap (26) on the transmission lever (20). The metering system according to claim 19.

21. The closing element (51) is removablely installed in the metering system (1). The metering system according to claim 4.

22. The closing element (51), together with the fluid unit (15), is detachably installed in the metering system (1). The metering system according to claim 21.

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