Metering valve comprising a precision mechanism adjustment means

Abstract

The invention relates to a metering valve (1) for metering a metering material, comprising an actuator unit (2) and a fluidic unit (3). The actuator unit (2) has at least one controllable actuator (4) for dispensing metering material from the fluidic unit (3). The actuator unit (2) has an adjustment mechanism (5) associated with the actuator (4) and designed to adjust the metering valve (1). The adjustment mechanism (5) has a setting element (50) which is movably mounted in the actuator unit (2) by means of an external thread (51). The adjustment mechanism (5) has an adjusting element (55) which is movably mounted in an internal thread (53) of the setting element (50) by means of an external thread (54). Preferably, a pitch (S2) of the external thread (51) is different from a pitch (S1) of the internal thread (53) of the setting element (50).

Description

Metering valve with gear-based fine adjustment The invention relates to a metering valve for dispensing a dosing agent, comprising an actuator unit and a fluid unit, wherein the actuator unit has at least one controllable actuator for dispensing dosing agent from the fluid unit, and wherein the actuator unit has an adjustment mechanism associated with the actuator and configured for adjusting the metering valve. The invention further relates to an actuator unit for a metering valve for dispensing a dosing agent and a method for adjusting a metering valve. Metering valves are used in a wide variety of applications to precisely dispense a medium, typically a liquid to viscous dosing agent. In microdosing technology, it is often necessary to apply very small quantities of the dosing agent to a target surface with high precision – that is, at the right time, in the right place, and in a precisely measured amount. The dispensing agent from a metering valve can be applied contact-based or non-contact-based, meaning without direct contact between the metering valve and the target surface. The dosing agent can be applied to the target surface, for example, in a diffuse, linear, and / or spot manner. Metering valves typically have a movable element, such as a plunger, which can be moved by an actuator inside the valve to dispense a metering agent through a nozzle. In jet valves, the plunger is propelled forward at relatively high speed toward the nozzle opening, ejecting a single droplet of the metering agent. The plunger can then be retracted in the opposite direction. In most valves, the plunger can be moved into a closed position by pressing firmly against a sealing seat in the nozzle opening and remaining there to temporarily close the valve. Depending on the metering agent, it may be sufficient for the plunger to remain in a retracted position, i.e., away from the sealing seat of the nozzle, without any metering agent being dispensed. In other metering valves, the nozzle can be briefly opened by retracting the movable element from the nozzle's sealing seat, allowing a drop of the metering material to escape from the nozzle, for example, due to gravity and / or pressure within the nozzle. The nozzle is then closed again by moving the movable element back against the sealing seat. For high dosing accuracy, it is essential that the elements of the dosing valve involved in dispensing the metering material are positioned as precisely as possible within the valve. This applies particularly to the spatial position of the actuator and the moving element within the dosing valve, especially in relation to the nozzle. For example, in jet valves, the amount of metering material that is dispensed depends on... during each ejection process from the nozzle, in particular from a (hydraulically) effective stroke of the plunger and / or the nozzle, i.e. e.g. from a distance traveled by the plunger in relation to the nozzle during each ejection movement. Regardless of the dispensing principle, precise setup of the entire system, particularly adjusting the relative position between the actuator and / or plunger and / or nozzle, is crucial for accurate dosing. This adjustment of the metering valve can be performed at the factory. The metering valve is typically adjusted so that, following actuator activation, a specific relative movement of the plunger occurs relative to the nozzle, thus dispensing the desired quantity of metering material through the nozzle. Readjustment is frequently necessary to maintain consistently high dosing accuracy during continuous operation of the metering valve. Readjustment may be required, for example, due to temperature fluctuations in the metering valve's piezoelectric actuator, wear and tear on moving parts of the metering valve, or the replacement of worn components.These and other factors can lead to a discrepancy between the actual quantity of dosing material dispensed and the target quantity of dosing material in the operation. Metering valves are known in which the position of an actuator within the housing can be mechanically changed and adjusted. For example, the housing of the metering valve may have conventional screws that press down on a piezoelectric actuator from above, allowing the actuator to be moved within the valve by turning the screws. It is also possible to arrange one or more spacers of a specific thickness between the housing and the piezoelectric actuator inside. This allows the position of the piezoelectric actuator within the metering valve housing to be adjusted within certain limits. However, this only allows for a relatively coarse change in the actuator's position. Therefore, it can happen that a specific target position, e.g., of the actuator within the housing, particularly in the micrometer range, cannot be set precisely enough to achieve the desired dosing accuracy due to the mechanical limitations of the adjustment mechanism. Another disadvantage can be that readjusting the actuator, e.g., during operation or a short break, is not easily possible. This can be the case with an internal adjustment mechanism, for example, one with spacers, where, for instance, the dosing valve housing must first be opened. This can result in the dosing valve being unnecessarily taken out of service for a period of time. It is an object of the present invention to at least reduce the disadvantages described above and to provide an adjustment mechanism that is as compact and simple in design as possible. This problem is solved by a metering valve according to claim 1, by an actuator unit for a metering valve according to claim 14 and by a method for adjusting a metering valve according to claim 15. A metering valve according to the invention for dispensing a metering substance comprises an actuator unit and a fluid unit. The actuator unit and the fluid unit are connected to each other, preferably detachably, during operation of the metering valve. The actuator unit has at least one controllable actuator for dispensing metering substance from the fluid unit. The metering substance is preferably a liquid to viscous substance. The actuator can be controlled and / or is designed such that metering substance is dispensed from the metering valve as a result of actuation of the actuator. The actuator is preferably operatively connected to a movably mounted element of the metering valve, in particular a plunger, in order to move it to dispense metering substance from the metering valve in the fluid unit, particularly relative to a nozzle. The actuator unit preferably comprises a housing, wherein the actuator, and optionally further elements of the metering valve, are arranged in a cavity inside the housing. The actuator unit has an adjustment mechanism associated with the actuator. This means that the adjustment mechanism preferably acts specifically and / or directly on the actuator or a part of the actuator. Preferably, other elements of the metering valve that are not part of the actuator are not directly contacted by the adjustment mechanism. The adjustment mechanism is designed to adjust the metering valve. This adjustment can preferably be achieved by moving the actuator or parts thereof within the actuator unit housing using the adjustment mechanism, and / or by moving the actuator or parts thereof into a (target) position within the housing. In particular, the adjustment mechanism is designed to set a specific parameter of the actuator during operation of the metering valve. The adjustment mechanism can preferably be coupled to the actuator in an axial direction, e.g., corresponding to the actuator's longitudinal extension and / or stroke direction. Preferably, the adjustment mechanism and the actuator are arranged on the same axis within the actuator unit. The adjustment mechanism can be mechanically arranged in series with the actuator within the housing. The adjustment mechanism has at least one adjusting element that is movably, preferably rotatably or screwably, mounted in the actuator unit, particularly in the housing of the actuator unit, by means of an external thread. Preferably, the housing comprises and / or includes and / or encloses the at least one controllable actuator, in particular the entire actuator. Accordingly, the entire actuator can be arranged completely (only) within the housing of the actuator unit. The housing can have a housing block and / or can be such. Preferably, the (entire) adjustment mechanism penetrates the housing, in particular a wall, and The adjustment mechanism extends at least partially into the housing cavity (in the assembled state), particularly to make contact with the actuator. Part of the adjustment mechanism, especially the adjusting element, is preferably screwed into a wall of the housing. The adjusting element is preferably accessible from outside the housing (in the assembled state). The adjusting element may include a threaded sleeve. In particular, the adjusting element may be a threaded sleeve. The threaded sleeve may have an external thread, preferably formed in or on an outer surface of the threaded sleeve. The threaded sleeve may include a cavity inside. An inner wall or interior surface of the threaded sleeve facing the cavity may have an internal thread. The internal thread of the threaded sleeve or the adjusting element can therefore be formed (only) within the threaded sleeve. The adjustment mechanism comprises an adjusting element that is movably, in particular rotatably or screwably, mounted in the internal thread of the adjusting element or threaded sleeve by means of an external thread. The adjusting element may include a threaded stud. In particular, the adjusting element may be a threaded stud. The adjusting element or threaded stud is preferably the part of the adjustment mechanism that acts on the actuator (directly or indirectly). The threaded sleeve preferably does not contact the actuator directly. Preferably, the threaded sleeve only contacts the housing of the actuator unit and the threaded stud. The adjustment mechanism can be designed such that (in the assembled state) the threaded stud engages with its external thread into the internal thread of the threaded sleeve and / or is rotatably mounted within it. The threaded sleeve engages with its external thread into a thread in the actuator unit housing and / or is rotatably mounted within the housing. This also connects the threaded stud, at least indirectly, to the actuator unit housing. The free end of the threaded stud can be in operative contact with the actuator. The thread in the actuator unit housing, into which the threaded sleeve is screwed, can be part of the adjustment mechanism. Particularly preferred is a pitch of the external thread of the adjusting element that differs from a pitch of the internal thread of the adjusting element and / or from a pitch of the external thread of the adjusting element. The adjustment mechanism is designed to change at least one position of the adjusting element in the actuator unit and / or to set a (specific) position of the adjusting element in the actuator unit. Preferably, the adjustment mechanism is designed to change the position of the adjusting element relative to the housing of the actuator unit and / or to set a (specific) position of the adjusting element relative to the housing of the actuator unit. Preferably, the adjustment mechanism can be used to change and / or set the position of the adjusting element relative to a nozzle of the metering valve, in particular a distance. Advantageously, the adjusting element can be moved between different (two or more) positions in the actuator unit, particularly within the housing, by means of the adjustment mechanism, in particular by means of the setting element. Preferably, the adjustment mechanism is designed to move the adjusting element along a threaded axis of the adjustment mechanism in different (opposite) directions. Particularly preferably, the adjustment mechanism is designed to move the entire adjusting element within the actuator unit, especially within the housing. Alternatively or additionally, the adjustment mechanism can be designed to change and / or adjust the position of the entire adjusting element within the actuator unit, especially within the housing. Advantageously, the adjustment mechanism is designed to be particularly simple and robust. In its simplest form, the adjustment mechanism comprises only the threaded sleeve and the threaded pin, which interact with a thread in the actuator unit's housing, thus requiring only two parts, which are also inexpensive to procure. The adjusting element and the adjusting element can be provided as separate parts. Because the adjusting element and the adjusting element interlock, at least partially, the adjustment mechanism is advantageously particularly compact and space-saving. Another advantage is that the adjustment mechanism, especially due to its compact design, can be arranged on a (common) axis with the actuator in the housing. This allows the entire metering valve to be particularly space-saving, and especially as narrow as possible. This, in turn, enables the smallest possible pitch or...High-density dosing patterns are achieved when using multiple dosing valves. Due to the compact design and / or by relocating the adjustment mechanism to the actuator axis, space can be freed up in other areas of the dosing valve, e.g., in the plunger area. This allows, for example, the integration of sensors in the plunger area, such as position sensors. A further advantage is that the adjusting element or threaded sleeve is accessible from outside the metering valve when installed. To actuate the adjustment mechanism, particularly to adjust the metering valve, the threaded sleeve can be screwed (deeper) into the actuator unit housing, for example manually, or unscrewed (further) from the housing. This rotational movement of at least the adjusting element or threaded sleeve relative to the actuator unit housing is part of the metering valve adjustment. Depending on the design, this can also move the adjusting element or threaded pin in the same (rotational) direction relative to the actuator unit housing. This results (directly or indirectly) in a change of position of the actuator within the housing. It should be noted that any movement or change in position of the actuator can occur in the micrometer or submicrometer range.In other words, movement of the actuator can occur at a microscopic level. It is also possible that, as a result of the activation of the adjustment mechanism, only a part of it moves. The actuator is moved and / or repositioned, while another part of the same actuator remains stationary or maintains its previous position. By changing the position of the actuator, the position of other elements of the metering valve can be (indirectly) changed and adjusted, in particular the position of the plunger and / or a stroke stop of the actuator. Advantageously, stepless adjustment of the metering valve can be achieved using the threads. Advantageously, initial adjustment or (re-)adjustment of the metering valve can be carried out without prior disassembly of the metering valve. For example, the adjustment mechanism can fulfill a mechanical compensation function, e.g., to compensate for operational wear of components of the metering valve. Adjustment can be carried out directly at the metering point. In principle, adjustment can also be carried out during operation. However, it is preferred that the adjustment be carried out in an inactive state of the metering valve, i.e., outside of active metering operation.In the context of the invention, adjustment of the metering valve refers to setting the metering valve to reduce deviations in the metering agent dispensed from a target value during metering operation to the extent necessary for a specific application. The purpose of the adjustment is, in particular, to ensure that the metering valve dispenses a consistently defined (target) quantity of metering agent during metering operation. A further advantage can be achieved by using an adjustment element where the pitch of the external thread and the pitch of the internal thread differ. This allows for particularly fine adjustment of the metering valve. Depending on the design, it is possible to position the actuator, or parts thereof, very precisely within the actuator unit housing. In particular, the actuator, or parts thereof, can be moved in different directions within the actuator unit housing in the micrometer or submicrometer range. By positioning the actuator within the housing as precisely as possible, and indirectly other elements of the metering valve as well, the metering accuracy can be further improved. The adjustment mechanism can be designed and / or operated such that, as a result of actuation (rotational movement) of the adjusting element, both the adjusting element and the adjusting element are moved relative to the actuator unit, preferably relative to the housing of the actuator unit. Consequently, the adjusting element and the adjusting element can simultaneously perform a relative movement to the actuator unit and / or within the housing. Therefore, when the adjusting element is actuated, preferably both elements are always moved and / or repositioned within the actuator unit. However, the direction and / or extent of the movement can differ. The invention further relates to an actuator unit for a metering valve for dispensing a metering substance, in particular for a metering valve according to the invention. The actuator unit is preferably designed to be used or operated in a metering valve. In particular, the actuator unit can be connected or coupled to a fluidic unit, e.g. detachably, to form a ready-to-use system. to form a metering valve. The fluidic unit can be configured as described in the context of the invention. However, the actuator unit can also be coupled with other fluidic units, provided that the fluidic unit, in combination with the actuator unit, provides a ready-to-use metering valve. The actuator unit has at least one controllable actuator for dispensing metering fluid from the (coupled) fluid unit. In the assembled state, the actuator is operatively connected to a movable element of the metering valve, in particular a plunger, to move it to dispense metering fluid onto the metering valve. The actuator unit has an adjustment mechanism associated with the actuator. This means that the adjustment mechanism preferably acts selectively and / or directly on the actuator. Preferably, other elements of the metering valve that are not part of the actuator are not directly contacted by the adjustment mechanism. The adjustment mechanism is designed to adjust the metering valve (in the coupled state of the actuator unit and fluid unit). The adjustment can preferably be achieved by using the adjustment mechanism to move the actuator or parts thereof within a housing of the actuator unit and / or to move the actuator or parts thereof into a (target) position within the housing. In particular, the adjustment mechanism is designed to set a specific parameter of the actuator during operation of the metering valve. The adjustment mechanism comprises an adjusting element, in particular a threaded sleeve, which is movably, and in particular rotatably, mounted in a housing of the actuator unit by means of an external thread. The adjustment mechanism further comprises an adjusting element, in particular a threaded pin, which is movably mounted in an internal thread of the adjusting element by means of an external thread. Preferably, the pitch of the external thread differs from the pitch of the internal thread of the adjusting element and / or from the pitch of the external thread of the adjusting element. The adjustment mechanism is designed to change and / or set the position of the adjusting element in the actuator unit, in particular in the housing of the actuator unit. Advantageously, the same effects described for a metering valve can be achieved with the actuator unit. This applies particularly if the actuator unit is connected to a fluidics unit as intended. The advantageous further developments described using an actuator unit of the metering valve can equally be implemented in an actuator unit on its own, i.e., independently of the rest of the metering valve. The invention relates to a method for adjusting a metering valve for dispensing a metering substance, in particular for adjusting a metering valve according to the invention. The metering valve has an actuator unit and a fluid unit, wherein the actuator unit has at least one controllable actuator. for dispensing metering fluid from the fluidic unit. The actuator unit has an adjustment mechanism, which is associated with the actuator and designed for adjusting the metering valve. It is possible, in principle, for the adjustment mechanism to be associated with the actuator in this process and arranged in the actuator unit housing in such a way that the adjustment mechanism effects an adjustment of the metering valve. This is possible, for example, during the initial adjustment of the metering valve. In particular, the adjustment mechanism can be arranged, or configured, so that a specific parameter of the actuator is set and achieved during operation. The adjustment mechanism includes an adjusting element that is rotated at least once in the process by a specific angle via an external thread within a housing of the actuator unit. The adjusting element can be screwed (at least partially) into the housing or (at least partially) unscrewed from it. The screwing or rotating movement of at least the adjusting element is part of the adjustment of the metering valve. The adjustment mechanism includes an adjusting element that is movably mounted via an external thread within an internal thread of the adjusting element. Preferably, the pitch of the external thread differs from the pitch of the internal thread of the adjusting element. In the process, the position of the adjusting element within the actuator unit, particularly within a housing of the actuator unit, is changed at least once by means of the adjustment mechanism.Alternatively, preferably additionally, the method involves setting a specific position of the adjusting element in the actuator unit, in particular in a housing of the actuator unit, at least once. Preferably, in the methods, the adjusting element is rotated or turned at least once by means of its external thread in the internal thread of the adjusting element. This optional step can include the adjusting element being or being mounted in a rotationally secure manner in the actuator unit, while the adjusting element is (simultaneously) rotated in a thread in the housing of the actuator unit. This rotational movement of the adjusting element relative to the adjusting element is preferably part of the adjustment of the metering valve. The procedure may optionally include the option of rotating the adjusting element and the adjusting element simultaneously and by the same amount (in the same direction) at least once. This allows for simultaneous rotation of both elements without changing their relative distance. In other words, the relative position of the two elements remains constant. Such a rotation of the adjusting element and the adjusting element can be part of the metering valve adjustment process. The advantageous further developments described in the description using an actuator unit of the metering valve can be taken into account accordingly in the procedure for adjusting the metering valve. Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, wherein the claims of one claim category may also be further developed analogously to the claims and description parts of another claim category and, in particular, individual features of different embodiments or variants may be combined to form new embodiments or variants. The fluidic unit of the metering valve can have a housing in which at least one nozzle with a nozzle opening and a feed channel for supplying metering fluid to the nozzle are arranged. The metering fluid can also be referred to as the metering medium. The nozzle can have an internal sealing seat. The plunger is preferably part of the fluidic unit and, during operation, projects at least partially into the fluidic unit. The housing of the fluidic unit can, in principle, be designed separately from the housing of the actuator unit. In this case, the two housing parts can be connected, preferably detachably, to form a complete housing. It is also possible for the fluidic unit and the actuator unit to be arranged in the same housing. The invention is not limited to a specific connection between the actuator unit and the fluidic unit. The special adjustment mechanism can be used in combination with differently operating metering valves and various actuator types. For example, the adjustment mechanism can be used with the metering valves mentioned above. Accordingly, the adjustment mechanism is not limited to the actuator types and metering valves described in more detail below. The adjustment mechanism can also be referred to as an adjusting mechanism. The invention is described below, without limitation, with reference to an adjusting element in the form of a threaded sleeve and an adjusting element in the form of a threaded stud. The adjustment mechanism is preferably designed to set a specific parameter of the actuator, in particular to a setpoint. The parameter is preferably selected from a target position of a piezoelectric actuator relative to the housing of the actuator unit, particularly during operation, and / or an adjustment position of a movable element of the metering valve, and / or a target stroke of the actuator during operation. Preferably, the adjustment mechanism can be used to set a target position of the actuator relative to the movable element and / or the nozzle. The actuator is preferably designed to move a movable element (synonymously referred to as a plunger) of the metering valve towards a nozzle of the metering valve during operation and / or to bring it into operative contact with a nozzle of the metering valve, so that metering material is ejected from a nozzle opening of the nozzle by means of the movable element. Preferably, the metering valve is a jet valve. The jet valve is preferably designed such that the plunger can temporarily close the nozzle opening of the nozzle (in a deflected state of the actuator). The plunger can therefore be moved into a closed position. In a jet valve, the metering fluid is actively ejected from the nozzle by an ejection movement of the plunger, also known as the ejector element, relative to the nozzle. To eject the metering fluid, the ejector element inside the nozzle can be pushed forward at relatively high speed in the direction of the nozzle opening, ejecting a single droplet of the metering fluid from the nozzle. During the ejection process, a tip of the ejector element comes into contact with the metering fluid to be dispensed and, due to the ejection movement of the ejector element and / or the nozzle, forces the metering fluid out of the nozzle of the metering valve. Following this ejection process, the ejector element can be moved back in the opposite direction.It is possible that, in addition to dispensing the metering material, the nozzle of the metering valve itself is moved in an ejection or retraction direction. In this case, the nozzle and the ejection element located inside the nozzle can be moved relative to each other, towards or away from each other, to eject the metering material. The actuator preferably comprises at least one piezoelectric actuator (or piezo actuator for short). Preferably, the actuator is a piezo actuator. The piezo actuator can be a monolithic piezoceramic multilayer actuator. This can be the case, in particular, but not exclusively, with a jet valve. The adjustment mechanism can be configured to set the position of the piezoelectric actuator relative to the housing of the actuator unit and / or to adjust the piezoelectric actuator within the housing. The adjustment of the piezo actuator is preferably carried out such that, as a result of the (activation) of the piezo actuator during operation, a specific target quantity of metering fluid is ejected from the nozzle. Accordingly, the piezo actuator can be moved in different directions within the housing and / or relative to the housing by means of the adjustment mechanism, in particular in the longitudinal direction of the piezo actuator or along a piezo axis.The piezo actuator and the adjustment mechanism are preferably arranged on the same (piezo) axis. The piezo axis preferably runs along the longitudinal extent of the piezo actuator. Preferably, a specific force, in particular a compression force, can be exerted on the piezo actuator by means of the adjustment mechanism to adjust the metering valve. Preferably, the piezo actuator comprises a plurality of stacked layers of a piezoelectrically active material arranged in a housing of the piezo actuator. Preferably, the housing of the piezo actuator can be arranged in the cavity within the housing of the actuator unit. In particular, the piezo actuator of the actuator unit can be hermetically encapsulated in a housing. Preferably, a monolithic piezoceramic actuator, especially a multilayer piezoceramic actuator, can be arranged in a hermetically sealed enclosure. Hermetically sealed encapsulation means that the housing surrounding the piezoceramic actuator is sealed so tightly that no substances can penetrate the housing from the outside, and vice versa. Advantageously, the adjustment mechanism can be designed to adjust the position of the housing of the piezo actuator relative to the housing of the actuator unit. To adjust the actuator unit and / or to adjust the housing of the piezo actuator within the housing of the actuator unit. Advantageously, the adjustment mechanism allows for the setting of a target arrangement between the piezo actuator, the plunger, and the nozzle. This adjustment can be made so that, as a result of a specific deflection of the piezo actuator, a precisely measured amount of metering material is ejected from the nozzle. For example, the piezo actuator can be moved in opposite directions along its axis within the housing using the adjustment mechanism. This is achieved by screwing the adjustment element (deeper) into the housing or (further) out of it. Advantageously, the metering valve with the adjustment mechanism includes an additional actuator for pinpoint positioning of the piezo actuator within the housing. This allows the high dynamics of the piezo actuator to be utilized almost entirely for the actual metering function of the metering valve. The target arrangement, or...The target position of the piezo actuator can be kept largely constant even during operation of the metering valve. The adjustment mechanism can advantageously be used to fulfill thermal compensation functions, also known as thermal balancing, and / or to fulfill mechanical compensation functions. The latter, in particular, is not limited to piezo actuators but can be generally advantageous for jet valves. The adjustment mechanism is preferably designed to set the position of the movable element relative to the nozzle of the metering valve and / or to adjust the movable element of the metering valve within the metering valve. The adjustment of the plunger is preferably carried out such that, as a result of the actuator, preferably the piezoelectric actuator, a specific target quantity of metering material is ejected from the nozzle during operation. Accordingly, the plunger can be moved in different directions within the housing and / or relative to the housing by means of the adjustment mechanism. Preferably, a change in the position of the actuator, in particular the piezoelectric actuator, effected by the adjustment mechanism, can be transmitted to the plunger for adjustment purposes.In other words, the positioning of the plunger and / or the adjustment of the (target) plunger position can be (indirectly) achieved by positioning the actuator within the housing via the adjustment mechanism. The actuator is preferably a piezoelectric actuator. However, this embodiment of the invention is not limited to a specific type of actuator. The metering valve preferably has a movement mechanism with a lever to transmit, and in particular translate, a deflection of the actuator, preferably the piezoelectric actuator, to the movable element via the lever. Preferably, the movement mechanism can include a transmission element, e.g., a lever system with a tiltable lever or the like, to increase the deflection of the actuator by a specific factor. In particular, the transmission element can be configured to establish a specific transmission ratio between a deflection or stroke of the actuator and a resulting to generate the resulting movement or stroke of the plunger. Accordingly, the actuator on one side and the plunger on the other can be arranged at two opposite ends of the tiltable lever. The movement mechanism is preferably part of the actuator unit. Advantageously, the adjustment mechanism can be designed to set the position of the movable element relative to the nozzle of the metering valve by means of the movement mechanism, and / or to adjust the movable element of the metering valve within the metering valve. Accordingly, the adjustment of the plunger can be achieved indirectly via the movement mechanism. Specifically, to adjust the plunger, a change in the position of the actuator, in particular the piezoelectric actuator, effected by the adjustment mechanism, can first be transferred to the movement mechanism and then to the plunger. In other words, the positioning of the plunger and / or the setting of the (target) plunger position can be achieved by positioning the actuator within the housing using the adjustment mechanism and transferring the change in position to the plunger via the movement mechanism. Advantageously, the translation element can also be used to transmit a change in the actuator's position, caused by the adjustment mechanism, to the plunger to a greater extent. This means that a comparatively small change in the actuator's position due to the adjustment mechanism can result in a relatively large change in the plunger's position. The actuator is preferably a piezoelectric actuator and / or the metering valve is preferably a jet valve. However, this embodiment of the invention is not limited to a specific type of actuator or metering valve. The adjustment mechanism can be designed to adjust or set the movable element so that, in particular a tip of the plunger, the movable element, in a deflected operating state of the actuator, is pressed into the nozzle with a defined (sealing) force, especially into a sealing seat. The sealing seat can be provided by a nozzle insert. Preferably, the adjustment mechanism can be used to set an adjustment position of the plunger in the metering valve (as an adjustment). The adjustment position of the plunger is preferably reached at the maximum possible deflection of the actuator, particularly the piezo actuator, as provided for during operation. Accordingly, the adjustment position can be set during the adjustment process and subsequently reached during operation. Preferably, to reach the adjustment position, a change in the position of the actuator, particularly the piezo actuator, effected by the adjustment mechanism, can be transferred to the plunger. In other words, the actuator can be positioned in the housing by means of the adjustment mechanism, or it can be moved to a target position. The actuator is moved to a position such that the plunger reaches an adjustment position. Preferably, the change in position of the actuator can be transmitted to the plunger by means of a movement mechanism. The adjust position is preferably characterized or defined by the fact that the plunger, in particular an ejection tip of the plunger, is pressed into the nozzle with a specific force. The force exerted by the plunger on the nozzle in the adjust position is referred to as the indentation force or sealing force. In the adjust position, the plunger can be pressed into a sealing seat of the nozzle such that a sealing area of ​​the nozzle is preferably completely filled by the plunger. The sealing area is understood to be an area in the sealing seat of the nozzle that is directly adjacent to the nozzle opening inside the nozzle (nozzle chamber). In the sealing area, the plunger and the nozzle can interact to create a seal, in particular by the plunger being pressed against the sealing seat. Preferably, a specific sealing force is generated against the nozzle by the plunger in the adjust position.The sealing force of the plunger can be, for example, at least 1 mN, preferably at least 1 N, preferably at least 10 N. Advantageously, such an adjustment of the plunger (as a calibration) allows for particularly precise setting of a specific relative position of the plunger tip to the nozzle insert in the deflected actuator state. This further improves the metering accuracy, especially in jet valves, since the ejected droplet size depends, among other things, on the hydraulically effective stroke of the plunger during the ejection movement. Furthermore, the hydraulically effective stroke of the plunger is comparatively small, particularly in piezoelectrically operated metering valves, for example, compared to other actuator types. The smaller the effective stroke of the metering valve, the more important a precise arrangement of the plunger and nozzle relative to each other within the metering valve becomes. Advantageously, the plunger can be reliably and easily moved into the adjustment position using the calibration mechanism. The actuator is preferably a piezoelectric actuator.In principle, this further development of the invention is not limited to a specific actuator type. The metering valve can have an actuator, which includes a pneumatic actuator, or pneumatic actuator for short. In particular, the actuator can be a pneumatic actuator. This can be the case especially with a jet valve. Preferably, the adjustment mechanism can be configured to set the position of a stroke limiter (also referred to as a stroke stop) for the pneumatic actuator and / or for the plunger relative to the housing of the actuator unit and / or within the housing of the actuator unit. Alternatively or additionally, the adjustment mechanism can be configured to adjust the stroke limiter within the housing of the actuator unit. The adjustment or setting of the stroke limiter is preferably carried out such that, as a result of the pneumatic actuator being activated during operation, a specific target quantity of metering material is dispensed from the nozzle. As a result of actuation of the adjustment mechanism, the stroke stop can be moved along the actuator axis in opposite directions.The actuator axis preferably corresponds to a stroke direction of the pneumatic actuator and / or a longitudinal extension of the plunger (especially if the plunger itself is part of the pneumatic actuator). Advantageously, the stroke of the pneumatic actuator can be limited during operation using the adjustment mechanism. Preferably, a target stroke of the pneumatic actuator can be set and / or kept constant during operation. Preferably, a plunger stroke limiter of the metering valve can be used in combination with the adjustment mechanism. Specifically, the stroke volume of the pneumatic actuator can be changed and / or set by the (relative) position of the stroke stop in the housing. The stroke volume can preferably refer to a (respective) actuator chamber of the pneumatic actuator that is to be filled with a pressure medium. Advantageously, the dynamics of the plunger movement can be set to a target value during operation using the adjustment mechanism. This is particularly advantageous for jet valves.Preferably, the stroke stop can be positioned such that the plunger has a specific (target) acceleration and / or a specific (target) speed during operation, particularly upon contact with the nozzle or the nozzle's sealing seat. This can further improve metering accuracy, especially in jet valves with pneumatic actuators. According to one embodiment, the metering valve has at least two actuators which, in operation, exert a tilting moment at different points on a lever rotatably mounted about a tilting axis, wherein preferably the actuators are positioned at an angle to each other, and wherein the adjustment mechanism is designed to set a position of at least one actuator relative to the housing of the actuator unit and / or to adjust the at least one actuator in the housing. Such a metering valve can have a frame housing unit (e.g., as the housing of the actuator unit) and a lever bearing unit with a lever support mounted on the frame housing unit. The metering valve preferably comprises a lever, preferably asymmetrical, rotatably mounted about a tilting axis by means of the lever support, with a two-sided lever arm extending substantially in a longitudinal direction of the lever, wherein one side of the lever arm, preferably the longer side, has a first actuator engagement point near the tilting axis and is in contact with an ejection element, preferably a plunger, at an end section farther from the tilting axis, and wherein the other side of the lever arm, preferably the shorter side, has a second actuator engagement point near the tilting axis.The metering valve comprises two actuators, preferably piezoelectric actuators, which, during operation, exert a tilting moment on the lever at the first and second actuator points in opposite directions. The actuators are positioned at an angle to each other, particularly in a V-shape. The actuators can be positioned at a maximum angle of 150°, preferably at a maximum angle of 120°, more preferably at a maximum angle of 90°, particularly preferably at a maximum angle of 60°, and most preferably at a maximum angle of 30°. The lever bearing unit, the lever, and the two actuators can together form a... form a movement mechanism which is clamped to the frame housing unit by means of at least one spring element, preferably a disc spring assembly, wherein preferably the spring element is arranged such that it clamps the lever bearing unit against the frame housing unit via the lever and via the two actuators. The basic principle of such a metering valve is disclosed in DE 10 2021 102 657 A1, the contents of which are hereby incorporated into this application. Details of the construction of such a metering valve are given in particular in the paragraphs

[0013] until

[0036] described in DE 10 2021 102 657 A1, the construction described therein being combined with an adjustment mechanism according to the present application. Accordingly, at least one actuator or both actuators (each) can be assigned an adjustment mechanism according to the present application. Advantageously, this allows the special effects described in paragraph

[0035] and

[0036] described in DE 10 2021 102 657 A1, in combination with a further improved dosing accuracy. For the sake of completeness, it should be noted that the metering valve according to the invention can generally, and in particular regardless of the arrangement of the actuators relative to each other and / or any lever mechanism, have two or more actuators, each of which is involved in the dispensing of metering material. Preferably, the adjustment mechanism is designed to set a position of at least one actuator, or both, relative to the housing of the actuator unit and / or to adjust the at least one actuator, or both actuators, within the housing. The adjustment mechanism is preferably designed such that the threaded sleeve has a portion that protrudes from the housing of the actuator unit when assembled. This protruding portion can provide a point of engagement for a mechanical tool to rotate or screw the threaded sleeve in opposite directions within the housing. Preferably, the outer portion, also referred to as the head, of the threaded sleeve or the adjustment mechanism can have an external hexagon. For example, the outwardly facing head of the adjustment mechanism can have a hexagonal screw. The head of the threaded sleeve is preferably closed on the outward side (facing away from the housing). The head of the threaded sleeve preferably has no thread. The threaded sleeve preferably has a further part that, in the assembled state, is (partially or completely) located within the housing of the actuator unit. This sleeve-like part can comprise the external thread and / or the internal thread of the threaded sleeve. Preferably, the sleeve-like part and the external part (head) of the adjustment mechanism are firmly connected to each other, in particular formed as a single piece. The adjustment mechanism is preferably designed such that the pitch of the external thread of the adjusting element is greater than the pitch of the internal thread of the adjusting element. and / or greater than the pitch of the external thread of the adjusting element. Preferably, the internal thread of the adjusting element (generally) has the same pitch as the external thread of the adjusting element. Particularly in the case of metric threads, the pitch denotes the (linear) distance traveled in one revolution of the respective thread (e.g., the threaded sleeve relative to the housing of the actuator unit). This corresponds to the distance between two thread crests in millimeters (formerly also referred to as pitch). It is also optionally possible for the pitch of the external thread of the adjusting element to be smaller than the pitch of the internal thread of the adjusting element and / or smaller than the pitch of the external thread of the adjusting element. This can be used to change the preferred direction of rotation for the respective axial adjustment direction. Preferably, the pitch of the external thread of the adjusting element is less than the pitch of a standardized fine thread of the same nominal size, particularly according to DIN 13-2 or DIN 13-3 (e.g., DIN 13-2:1999-11 or DIN 13-3:1999-11). It is generally preferred that the external and internal threads of the adjusting element and the external thread of the adjusting element are each metric ISO threads. For example, the external thread of the adjusting element can be a metric thread with a nominal size of M4 or M5, with a pitch of less than 0.5 mm, preferably less than 0.4 mm. If the external thread of the adjusting element is a metric thread with a nominal size of M6 or M8, the pitch can be less than 0.75 mm, preferably less than 0.5 mm. It is generally preferred that the pitch of the external thread of the adjusting element is less than 0.3 mm, preferably less than 0.25 mm, and in particular less than 0.2 mm. It is also optionally possible for the pitch of the external thread of the adjusting element to be the same as the pitch of a standardized fine thread of the same nominal size, in particular according to DIN 13-2 or DIN 13-3 (e.g. DIN 13-2:1999-11 or DIN 13-3:1999-11). Preferably, the external thread of the adjusting element can be a metric thread of type M7, wherein the internal thread of the adjusting element and / or the external thread of the adjusting element is a thread of type M5. Alternatively, the external thread of the adjusting element can be a thread of type M6, wherein the internal thread of the adjusting element and / or the external thread of the adjusting element is a thread of type M4. In principle, the respective thread size and / or the combination of the thread sizes involved can be determined by the type and size of the actuator. Preferably, the external thread of the adjusting element is a metric thread M7, and the internal thread of the adjusting element is a metric thread M5. Preferably, the external thread has a pitch of 0.35 mm, and the internal thread has a pitch of 0.30 mm. The adjustment mechanism is preferably designed such that a pitch difference or pitch variation between the external thread of the adjusting element and the internal thread of the adjusting element and / or the external thread of the adjusting element, particularly regardless of the respective thread size, is 0.1 mm or less, preferably at most 0.05 mm, more preferably at most 0.04 mm, more preferably at most 0.03 mm, and in particular from 0.025 mm to 0.01 mm. The adjustment mechanism is preferably designed such that the adjusting element or threaded sleeve and the adjusting element or threaded stud are movable relative to each other in an axial direction. Preferably, the threaded sleeve and the threaded stud can be screwed together or (at least partially) unscrewed by rotating the threaded sleeve. The threaded stud can thus be recessed more or less far or deeply into the inside of the threaded sleeve (for adjustment). A direction of movement of the threaded sleeve and the threaded stud relative to each other is preferably parallel to an outlet or ejection direction of metering material from the nozzle of the metering valve. Preferably, the direction of movement is parallel to and / or along a threaded axis or actuator axis. The threaded axis preferably runs through the center point of the external thread and / or the internal thread of the adjusting element.Particularly preferred is the direction of movement parallel to and / or along the longitudinal extent of the piezoelectric actuator. In particular, the adjustment mechanism is designed such that during a relative movement between the adjusting element and the adjusting element in the axial direction, both the adjusting element and the adjusting element are moved or change their respective positions in the actuator unit and / or in the housing of the actuator unit. The adjustment mechanism preferably includes an anti-rotation device for the adjusting element or the threaded stud. The anti-rotation device comprises an elongated slot in the threaded stud into which an anti-rotation pin or locking bolt engages (in the assembled state), and in particular can engage temporarily. Advantageously, the rotational position of the threaded stud relative to the thread axis can be fixed by a locking bolt in the elongated slot. The elongated slot preferably extends along the axial direction of movement of the threaded sleeve and the threaded stud relative to each other. A longitudinal extension of the elongated slot parallel to the thread axis and / or the actuator axis is preferred. The anti-rotation pin can preferably be movably arranged in the elongated hole in the longitudinal direction of the elongated hole. Preferably, the anti-rotation pin can penetrate the housing of the actuator unit and / or be accessible from outside the housing. Preferably, a portion of the anti-rotation pin that is outside the elongated hole in the assembled state can be screwed to the housing of the actuator unit. Accordingly, the anti-rotation pin can have a screw-like portion, in particular with a thread, by means of which the anti-rotation pin is (removably) fixed in the housing. The anti-rotation pin can have a head at its end. The head engages in the elongated hole. The head is preferably unthreaded. Advantageously, this allows the threaded stud to be displaced along the thread axis when the threaded sleeve is rotated, with this movement being determined solely by the threaded sleeve. Preferably, the adjustment mechanism can be designed such that the threaded stud is temporarily secured against rotation, particularly during rotation of the threaded sleeve within the housing. In other words, the threaded stud can be locked or fixed within the housing during actuation of the adjustment mechanism. Consequently, the threaded sleeve rotates (actively) within the housing, and the threaded stud rotates (passively) relative to the threaded sleeve. This allows the position of the threaded stud relative to the housing and / or the threaded sleeve to be changed and / or adjusted. Alternatively or additionally, the anti-rotation device of the adjustment mechanism can include an anti-rotation pin that engages in an elongated hole in the threaded stud, at least temporarily, particularly when assembled. The anti-rotation pin is preferably movably arranged in the elongated hole in the longitudinal direction. The anti-rotation pin can be designed to limit an adjustment range of the adjustment mechanism (when assembled). In particular, an (upper) end position and a (lower) opposing end position of the threaded stud can be defined by means of the anti-rotation pin. The anti-rotation device can preferably be constructed as described above. Advantageously, the adjustment range of the adjustment mechanism can be limited by means of an anti-rotation device, in particular by means of the anti-rotation pin. This prevents the adjustment mechanism, especially the threaded stud, from being completely unscrewed from the threaded sleeve. Advantageously, this also prevents the plunger from achieving an excessively high sealing force, for example, due to incorrect positioning of the piezo actuator. Preferably, the adjustment range of the adjustment mechanism along the thread axis can also be defined by the design or longitudinal extent of the elongated hole. Advantageously, the anti-rotation pin simultaneously secures the threaded stud against rotation. In a preferred method for adjusting the metering valve, it can be provided that the adjusting element is at least temporarily secured or fixed against rotation, while simultaneously the adjusting element is turned or screwed into the housing via the external thread (for adjustment). The adjusting element can be screwed into the housing or unscrewed (section by section) from the housing. It is generally preferred that the external thread and the internal thread of the threaded sleeve are aligned. Accordingly, a (rotational) movement of the threaded sleeve in The actuator unit's housing is designed so that the (rotation-protected) threaded stud is moved upwards relative to the threaded sleeve, or into the threaded sleeve. This allows the actuator's position within the housing, and indirectly the position of the other elements of the metering valve, to be changed. If the threaded sleeve and stud are screwed together as a result of actuating the adjustment mechanism, additional space can be provided for the actuator within the housing. This allows at least a portion of the actuator, pointing towards the side of the housing containing the adjustment mechanism, to be moved or repositioned slightly. This can, for example, compensate for thermally induced expansion of a piezoelectric actuator. The adjustment of the metering valve, or the change in the actuator's position, can advantageously be stepless and as precise as possible, particularly in the (sub-)micrometer range. A (rotational) movement of the threaded sleeve out of the housing, in the case of synchronous threads, causes the (anti-rotation) threaded stud to move downwards relative to the threaded sleeve, or out of the threaded sleeve altogether. This reduces the space available for the actuator within the housing. The actuator can be (further) compressed using the adjustment mechanism. This allows at least part of the actuator to be moved slightly towards the nozzle and / or the movement mechanism. Alternatively, the external thread and the internal thread of the threaded sleeve may be opposite in direction. In this case, a (rotational) movement of the threaded sleeve into the housing causes the (anti-rotational) threaded stud to move downwards relative to the threaded sleeve, or out of the threaded sleeve altogether. The effects described above can also be achieved in reverse with this method. Advantageously, the adjustment mechanism with a temporarily (anti-)rotation threaded pin, utilizing the effects described above, allows not only the setting of a target position of a piezoelectric actuator relative to the housing, but also the setting of an adjustment position of a movable element of the metering valve and / or a target stroke of the actuator during operation. Advantageously, using threads with different pitches for the threaded sleeve and the threaded stud allows for particularly precise adjustment of the metering valve. This effect can be further enhanced by using an exceptionally low pitch on the external thread of the threaded sleeve, smaller than that of comparable standardized fine threads. This minimizes the distance the threaded sleeve moves relative to the housing per revolution, enabling very precise and stepless adjustment. A particular advantage arises from minimizing the difference in pitch between the external and internal threads of the threaded sleeve. This allows for a smaller distance the threaded stud moves along the thread axis per revolution of the threaded sleeve. The thread axis should be as small as possible. It is preferably coaxial with the (piezo) actuator axis. Each revolution of the threaded sleeve (around the thread axis) can displace the threaded stud, and thus the actuator and any other elements of the metering valve, by the difference in thread pitch. In other words, the forward (or retract) movement of the threaded stud relative to the housing is equal to the difference in the two thread pitches and proportional to the rotation angle of the threaded sleeve. This allows for particularly fine adjustment of the metering valve, also known as fine adjustment. Advantageously, this enables fine adjustment of the metering valve elements in the micrometer range, and possibly even in the nanometer range. Accordingly, the adjustment mechanism can be a fine adjustment or micrometer adjustment. These advantageous effects are particularly noticeable when combined with an anti-rotation device for the threaded stud.Since the relative movement of the threaded sleeve and the threaded stud is achieved by means of several threads that interlock, the adjustment mechanism provides a geared fine adjustment. It should be noted that the anti-rotation device can only be activated or active temporarily. In particular, it is possible, for example as part of the adjustment procedure, for the adjusting element and the adjusting element to be initially rotated simultaneously and to the same extent in the same direction. For instance, in a first step, the threaded sleeve can be screwed into the thread of the actuator unit housing together with the threaded stud until a certain depth is reached. Subsequently, in a further step, the threaded stud can be secured against rotation, whereby the threaded sleeve is rotated further by a specific angle (e.g., deeper into or out of the housing). This allows for fine-tuning of the metering valve. For example, the anti-rotation device can remain activated until the adjustment is complete.In principle, the anti-rotation device can also be active during operation of the metering valve, i.e., after adjustment has been made. It should be noted that the use of the anti-rotation device is optional. The adjustment mechanism can be designed and / or operated in such a way that the threaded sleeve and the threaded stud are rotated simultaneously and in the same direction (relative to the housing), and in particular by the same amount. The adjustment mechanism is preferably designed such that at least one of its threads has one or more of the following materials, in particular is formed from: stainless steel or stainless steels, electropolished stainless steel or electropolished stainless steels, hardened or surface-hardened stainless steel or hardened or surface-hardened stainless steels, electropolished and hardened or surface-hardened stainless steel or electropolished and hardened or surface-hardened stainless steels, cold-worked stainless steel or cold-worked stainless steels, stainless steel with a carbonitrided or nitrided surface or stainless steels with a carbonitrided or nitrided surface, hardened carbon steel (carbon steel or unalloyed quality steel) with or without a carbonitrided or nitrided surface or hardened carbon steels with or without a carbonitrided or nitrided surface, hardened tool steel or hardened tool steels, Carbide ceramics Coating(s) to increase surface hardness and / or to reduce the coefficient of friction. Preferably, a (respective) thread can also comprise a combination of the aforementioned materials (with or without surface treatment), and in particular, consist entirely of them. It is preferred that at least the internal thread of the adjusting element and the external thread of the adjusting element consist of one of the aforementioned materials (or a combination thereof). Preferably, the internal thread of the adjusting element and the external thread of the adjusting element are formed from the same material or from the same combination of materials. In principle, the internal thread of the adjusting element and the external thread of the adjusting element can consist of different materials and can then preferably have matched material pairings. Optionally, the external thread of the adjusting element and / or the thread in the housing of the actuator unit can also consist of one of the aforementioned materials (or a combination thereof).It is possible that the entire threaded sleeve and / or the entire threaded stud is made of one of the aforementioned materials (or a combination thereof). Advantageously, the aforementioned materials ensure that the threads of the adjustment mechanism remain dimensionally stable and do not deform, even under high preload and impulse forces. This can occur with excessively soft materials during operation. Pure stainless steel tends to cold weld threads, a phenomenon significantly reduced when the surfaces are hardened. It has been shown that the smoother and harder the thread surfaces, the lower the operating torque required to adjust the mechanism. If the threaded sleeve, in particular, is too hard, for example, even in the core material, it can easily break or shear off under torsion. The selected materials thus facilitate the operation of the adjustment mechanism and increase its reliability. The adjustment mechanism is preferably designed for manual operation. Preferably, the threaded sleeve, which is partially screwed into the housing, can be rotated manually or with a tool in one direction (or the opposite direction) to actuate the adjustment mechanism. Alternatively or additionally, the adjustment mechanism can be designed to be controlled or operated in an automated process. Accordingly, automatic adjustment of the metering valve is possible. For this purpose, the adjustment mechanism can have a controllable drive unit for the threaded sleeve and / or the anti-rotation device to rotate the threaded sleeve in different directions or to (de)activate the anti-rotation device. The threaded stud preferably comprises a (first) part with an external thread, which, in the assembled state, extends at least partially into or is screwed into the sleeve-like part of the threaded sleeve. The threaded stud preferably has a further (second) part, particularly without an external thread, which, in the assembled state, lies outside the sleeve-like part of the threaded sleeve and / or directly contacts at least a part of the actuator, preferably the piezoelectric actuator. This (second) part of the threaded stud is preferably round in cross-section. The (second) part of the threaded stud can be matched to the diameter of the cavity in the housing of the actuator unit. Consequently, the threaded stud can have a multi-part structure. For example, the threaded stud can have at least one piston (as a first part) that encompasses the external thread of the threaded stud. Additionally, the threaded stud can have an element, e.g., a connecting element (as a second part), through which the threaded stud is in contact with the actuator, in particular the piezo actuator, or the stroke stop. The connecting element, or second part, is preferably designed to transmit a specific force to the piezo actuator for adjustment. The connecting element preferably has no thread. Preferably, the elongated hole in this additional element, or in the second part, is also unthreaded. It is possible that the first part and the second part of the threaded stud, e.g., the piston and the connecting element, are rigidly connected to each other or formed as a single piece. Alternatively, it is possible that the first part and the second part of the threaded stud, e.g., the piston and the connecting element, are formed separately and loosely, i.e.,The actuators are unconnected and arranged within the housing. This is particularly possible if the actuator, e.g., the piezo actuator, is held under preload within the housing (relative to the actuator axis), and the adjustment mechanism is also under preload. The actuator, especially the piezo actuator with a housing, can be arranged in a precisely fitting bore within the housing, thus preventing lateral movement (perpendicular to the actuator axis). It should be noted that the described adjustment mechanism can also be used in direct-acting jet valves, i.e., without a lever-based movement mechanism. This applies particularly to direct-acting jet valves with piezo actuators. Due to the very fine adjustment capability (fine-tuning), e.g. in the sub-micrometer range, sufficiently precise adjustment, e.g. of the plunger, can be achieved even without the effect of the movement mechanism. The metering valve can include a control unit to regulate the intended dispensing of the metering substance. The control unit can be integrated into the metering valve and / or implemented externally or separately from the metering valve. The control unit can, at a minimum, control the operation of the actuator. If a motorized version of the adjustment mechanism is provided, the control unit can also control the operation of the adjustment mechanism, in particular the drive mechanism. Furthermore, the control unit can be connected to optional sensors of the metering valve to obtain (measured) values ​​and, optionally, process them for regulating the metering operation. Accordingly, the metering valve can have one or more temperature sensors, preferably for detecting the actuator temperature. Alternatively or additionally, the metering valve can have one or more (position) sensors to detect the position of the plunger, particularly during operation of the metering valve. The metering valve can include at least one force sensor to determine a force exerted on the actuator, particularly by means of the adjustment mechanism, and preferably to determine a sealing force of the plunger based thereon (by means of the control unit). The corresponding measured values ​​can be obtained by means of a force sensor in the plunger or in the nozzle, or alternatively by means of a force sensor to determine a contact force of the adjustment mechanism (with respect to the actuator). The force sensor is preferably configured to determine the force exerted on the (piezo) actuator by means of the adjustment mechanism. In particular, the force sensor can also be configured to determine the sealing force of the plunger against the nozzle based on the force sensor's measured values, using an evaluation unit (which can also be part of the control unit). Preferably, the force sensor can be arranged in the same line of force as the adjustment mechanism and the (piezo) actuator. For example, the force sensor can be arranged at a support point or contact point of the adjustment mechanism opposite the (piezo) actuator. Advantageously, the force sensor allows for direct control to maintain a constant force. In particular, the force sensor enables constant regulation of the plunger's sealing force. Since the overall system's spring stiffness should not change during operation, seamless control is possible in all operating modes, including hold mode. This is especially beneficial when combined with an automatically adjustable adjustment mechanism, as the control unit can independently regulate the mechanism based on the force sensor readings to achieve the desired sealing force. 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 show: Figure 1 shows a section through a metering valve according to the invention, Figure 2 shows an enlarged section of the metering valve from Figure 1 , Figure 3 shows part of a metering valve according to the invention. Figure 1 schematically shows a longitudinal section through a metering valve 1 according to one embodiment of the invention. The metering valve 1 is, by way of example, a jet valve. The metering valve 1 has an actuator unit 2 and an associated fluid unit 3, which are detachably connected to each other by means of two screws. The actuator unit 2 has a housing 20 with a cavity 21 therein, also referred to as the actuator chamber 21. A piezoelectric actuator 4 is arranged in this cavity 21 as the actuator 4 of the metering valve 1. The piezoelectric actuator 4 is connected to a control unit 6, also shown schematically, by means of actuator control connections 62 and control cables 61, which are shown schematically. The signal connection of the piezoelectric actuator 4 to the control unit 6 is shown here purely by way of example and schematically. The control unit 6 is configured, at least, to control the operation of the piezoelectric actuator 4 and thus the metering operation of the metering valve 1. The piezoelectric actuator 4 is arranged lengthwise in the cavity 21 and directly contacts an adjustment mechanism 5 of the metering valve 1 at its upper end. This is described in more detail with reference to Figure 2. At its opposite, lower end, the piezoelectric actuator 4 is supported by a pressure piece 4' on a lever 9 of a movement mechanism 7. Via the movement mechanism 7 with the lever 9, which projects from the actuator chamber 21 into an adjacent action chamber, a movable element 30 is actuated by the piezoelectric actuator 4 such that the metering substance to be dispensed from the fluidic unit 3 in the desired quantity at the desired time in an ejection direction R or exit direction R. The lever 9 of the movement mechanism 7, which serves to transmit the actuator movement to the movably mounted element 30, also referred to as plunger 30 or ejector element, rests on a lever bearing 8 at the lower end of the actuator chamber 21 and can be tilted about a tilting axis K via this lever bearing 8. A lever arm of the lever 9 projects into the action chamber through an opening. In the action chamber, the lever arm has a contact surface 10 facing towards the plunger 30, which presses against a contact surface 32 of a plunger head 31. Figure 1 clearly shows that the contact between the piezo actuator 4 and the lever 9 takes place in an area between the lever bearing 8 and the contact surface 10 of the lever 9 facing the plunger 30. The contact point is located closer to the lever bearing 8 than to the contact surface 10 in order to achieve a desired transmission ratio, where a small movement of the piezo actuator 4 causes a larger movement of the plunger 30. In the embodiment shown here, the contact surface 10 of the lever 9 is permanently in contact with the contact surface 32 of the plunger head 31, by means of a plunger spring 33 pressing the plunger head 31 from below against the lever 9. The plunger spring 33 is supported downwards on a plunger bearing 35, to which a plunger seal 34 is attached. The lever 9 rests on the plunger 30. However, there is no fixed connection between the two components 9 and 30. In principle, it would also be possible for there to be a gap between the plunger 30 and the lever 9 in the initial or rest position of the plunger spring 33. To enable a nearly constant preload of the drive system (lever-piezo actuator motion system), the lever 9 is pushed upwards at the end where it comes into contact with the plunger 30 by an actuator spring 36. The plunger spring 33 pushes the plunger head 31 away from the plunger bearing 35 in an axial direction upwards. This also pushes a tip 37 away from a sealing seat 40 of a nozzle 38. This means that, without external pressure from above on the contact surface 32 of the plunger head 31, the plunger tip 37 is located at a distance from the sealing seat 40 of the nozzle 38 when the plunger spring 33 is in its rest position. Thus, in the rest state (unexpanded state) of the piezo actuator 4, a nozzle opening 39 is also open. When the piezo actuator 4 is deflected or expanded, the plunger tip 37 is pressed into the sealing seat 40 of the nozzle 38 with a defined sealing force. The plunger 30 can be in an adjustment position during this process. The metering fluid is supplied to the nozzle 38 via a nozzle chamber 41, to which a supply channel 42 leads. The supply channel 42 opens at its other end into a fluid connection 43. During operation, the fluid connection 43 can be connected, for example, to a metering fluid cartridge (not shown) or to a permanent metering fluid supply (not shown). The fluid unit 3 can have further elements not shown here, such as a heating device for temperature control of the metering fluid within the fluid unit 3 and / or sensors to detect the position of the plunger 30. The metering valve 1 can also include several differently temperature-controlled heating zones for the metering fluid, where, for example, a first heating zone is assigned to the nozzle 38, a second heating zone to the fluid unit 3, e.g., the supply channel 42, and a third heating zone to the metering fluid cartridge (not shown). In Figure 2, the part of the metering valve 1, which is marked with dashed lines in Figure 1, is enlarged and also shown schematically. Figure 2 shows that the adjustment mechanism 5 has an adjusting element 50, here a threaded sleeve 50, and an adjusting element 55 screwed to it, here a threaded stud 55. The threaded sleeve 50 has a first part T1, which here points upwards and is (completely) located outside the housing 20 of the actuator unit 2. This part The externally accessible part T1 comprises a head 52' of the threaded sleeve 50 or of the adjustment mechanism 5. The head 52' includes an engagement point 52 for a mechanical tool, here in the form of an external hexagon 52. For example, the threaded sleeve 50 can be rotated in different directions by means of a hexagon key (not shown) as a tool that interacts with the external hexagon 52 to adjust the metering valve 1. The external part T1, in particular the head 52', is not threaded. The threaded sleeve 50 has a further sleeve-like part T2, which has an external thread 51 and an internal thread 53. The first part T1, or head 52', and the sleeve-like part T2 are formed as a single piece. The sleeve-like part T2 is at least partially screwed into the housing 20. The external thread 51 of the threaded sleeve 50, preferably a metric ISO thread, is screwed into an internal thread 22 of the housing 20 of the actuator unit 2. The external thread 51 has a thread size G2, or nominal size, which is complementary to the nominal size of the internal thread 22 of the housing 20 of the actuator unit 2. The threaded sleeve 50 can be screwed into or out of the housing 20 by means of its external thread 51, which interacts with the internal thread 22 of the housing 20, as a result of a rotary or screwing movement. The threaded stud 55 has an external thread 54, preferably a metric ISO thread, by means of which it is screwed to the internal thread 53 of the threaded sleeve 50. The internal thread 53 of the threaded sleeve 50 has a thread size G1 or nominal size that is complementary to the nominal size of the external thread 54 of the threaded stud 55. The threaded stud 55 comprises a piston 56 (as the first part of the threaded stud 55), which has the external thread 54, and a connecting element 57 (as the second part of the threaded stud 55). In the case shown here, the connecting element 57 is formed integrally with the piston 56. However, it is also possible for the piston 56 and the connecting element 57 to be formed separately. The connecting element 57 rests on one end of the piezo actuator 4 and makes direct contact with it there. The connecting element 57 is arranged and designed to transmit a specific force to the piezo actuator 4 for adjustment. Figure 2 further shows that the pitch S2 of the external thread 51 of the threaded sleeve 50 is larger than the pitch S1 of the internal thread 53 of the threaded sleeve 50 or of the external thread 54 of the threaded stud 55. The external thread 51 is, for example, a metric thread M7, while the internal thread 53 is, for example, a metric thread M5. For instance, the external thread 51 has a pitch of 0.35 mm, while the internal thread 53 has a pitch of 0.30 mm. In this example, the external thread 51 and the internal thread 53 of the threaded sleeve 50 are aligned. The adjustment mechanism 5 is designed to prevent rotation of the threaded stud 55 during a rotational movement of the threaded sleeve 51. The threaded stud 55 is mounted here, at least temporarily, in a rotationally secure manner. The adjustment mechanism 5 comprises an elongated anti-rotation pin 59 that penetrates the housing 20 of the actuator unit 2 and, in the assembled state, engages with one end in an elongated hole 58 in the threaded stud 55. The anti-rotation pin 59 has a portion 59" with an external thread for releasably screwing the anti-rotation pin 59 into the housing 20. The portion 59' that extends into the elongated hole 58 is unthreaded. This portion 59', also referred to as the head, is freely movable in the elongated hole 58 in the assembled state, with respect to the longitudinal extent of the elongated hole 58.Figure 3 shows that a longitudinal extension of the elongated hole 58 is parallel to a direction R' in which the threaded sleeve 50 and the threaded stud 55 can be moved relative to each other. Furthermore, the longitudinal extension of the elongated hole 58 is parallel to an axis X (Figure 2), which represents an actuator axis X and a thread axis X. Figure 2 shows that the adjustment mechanism 5 and the piezo actuator 4 are arranged on the same axis X in the actuator unit 2. Accordingly, the piezo actuator 4 can be moved in different directions along the axis X, i.e., along the piezo axis X and the thread axis X, by means of the adjustment mechanism 5 within the housing 20 or relative to the housing 20. The piezo axis X and the thread axis X pass through the center point of the threaded sleeve 50, which has a round cross-section (at least with respect to part T2), and the threaded stud 55, which also has a round cross-section. To actuate the adjustment mechanism 5, i.e., to adjust the metering valve 1, the threaded sleeve 50 can be rotated in one direction by means of the point of application 52. During the rotation, the threaded stud 55 is preferably secured against rotation by the anti-rotation pin 59 being located in the elongated hole 58. A complete rotation of the threaded sleeve 50 about the threaded axis X into the housing 20 results in the (anti-rotation) threaded stud 55 being moved upwards a short distance. As a result of the rotation of the threaded sleeve 50, the threaded sleeve 50 and the threaded stud 55 are moved relative to each other. This relative movement occurs in a direction R' that is parallel to the threaded axis X or actuator axis X.A displacement of the threaded stud 55, and thus also of the piezo actuator 4 and other elements of the metering valve 1, corresponds to a difference in the two pitches S2 and S1 (e.g., S2-S1 = 0.05 mm) per complete revolution of the threaded sleeve 50 around the thread axis X. A forward (or retract) movement of the threaded stud 55 relative to the housing 20 in the direction R' is equal to the difference in the two pitches S2 and S1 and proportional to the rotation angle of the threaded sleeve 50 around the thread axis X, provided the rotational position of the threaded stud 55 is fixed. In the case shown here, a rotation of the threaded sleeve 50 into the housing 20 causes the (rotationally secure) threaded stud 55 to be screwed away from the piezo actuator 4 and upwards. the cavity 21 is slightly enlarged. Depending on the design of the adjustment mechanism 5, this enlargement can be in the sub-micrometer range. Thus, as a result of actuation of the adjustment mechanism 5, the piezo actuator 4 can be slightly repositioned in the direction R' and, in this case, moved upwards. In this example, the piezo actuator 4 is also under preload due to the movement mechanism 7 (Figure 1) and is therefore held in direct contact with, or pressed against, the threaded stud 55, even when the adjustment mechanism 5 is actuated. A rotational movement of the threaded sleeve 50 in the opposite direction, i.e., out of the housing 20, results in the (rotationally secure) threaded stud 55 being screwed downwards in the direction R' towards the piezo actuator 4. This increases the force exerted on the piezo actuator 4 by the adjustment mechanism 5. Consequently, the piezo actuator 4 is slightly repositioned downwards in the direction R' (e.g., in the micrometer range). This change in position of the piezo actuator 4 is transmitted to the plunger 30 by means of the movement mechanism 7 (Figure 1). This allows, for example, the plunger tip 37 to be pressed into the sealing seat 40 of the nozzle 38 with a defined sealing force in an adjustment position, i.e., in the deflected state of the piezo actuator 4. This enables adjustment of the metering valve 1. Figure 3 shows a part of a metering valve 1 according to the invention, although some components, in particular parts of the actuator unit, are not shown. The adjustment mechanism 5 corresponds in design to that shown in Figure 2. Accordingly, the adjustment mechanism 5 has a threaded sleeve 50 as an adjusting element 50 with an external thread 51, which, in the assembled state, is screwed into a thread in the housing of the actuator unit. It can be seen that the unthreaded area of ​​the threaded sleeve 50 has a point of engagement 52 in the form of an external hexagon 52. The threaded stud 55 is at least partially screwed into the inside of the threaded sleeve 50 by means of its external thread 54. The adjusting element 57 of the threaded stud 56 does not include a thread and forms the elongated hole 58. In the assembled state, the anti-rotation pin 59 is located in the housing of the actuator unit and extends through it.The anti-rotation pin 59 is arranged (temporarily) immovably relative to the housing in the assembled state, e.g. by means of a screw connection, whereby the adjusting element 57, which engages with the anti-rotation pin 59 by means of the elongated hole 58, is secured against rotation. As a result of rotating the threaded sleeve 50 around the thread axis X in the direction R, e.g., clockwise or counterclockwise, the threaded stud 55 is moved upwards or downwards in the direction R'. The direction of movement of the threaded stud 55 and the threaded sleeve 50 relative to each other is along the thread axis X, i.e., along the piezo axis X. Since the longitudinal extent of the elongated hole 58 is parallel to the thread axis X, the anti-rotation pin 59 is movably mounted at its end (with its head) in the elongated hole 58. This allows relative movement between the threaded sleeve 50 and the threaded stud 55 during adjustment, provided the threaded stud 55 is secured against rotation. A movement of the threaded pin 55 in the direction R' is transmitted to the piezo actuator 4 by means of the adjusting element 57. Since the piezo actuator 4 is arranged under preload in the metering valve 1 in the assembled state, the change in position of the piezo actuator 4 is transmitted to the plunger in the fluidic unit 3 by means of the movement mechanism 7. The adjustment can preferably be carried out such that the plunger is moved into an adjust position as a result of the actuation of the adjustment mechanism 5. Finally, it should be noted once again that the metering valves described in detail above are merely exemplary embodiments which can be modified in various ways by a person skilled in the art without leaving the scope of the invention. The invention is not limited to jet valves or piezo actuators. 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 1 metering valve 2 actuator units 3 Fluidic Unit 4 Actuator / Piezo actuator 4' pressure piece 5 Adjustment mechanism 6 Control unit 7 Movement mechanism 8 lever bearings 9 levers 10 Contact surface lever 20 Housing actuator unit 21 Cavity / Actuator chamber 22 internal thread actuator unit 30 movable element / plunger 31 Piston head 32 Contact surface plunger 33 Pushrod spring 34 Tappet seal 35 tappet bearings 36 Actuator spring 37 Point / Pestle Point 38 nozzle 39 Nozzle opening 40 Sealing seat 41 Nozzle chamber 42 Feed channel 43 Fluidic connection 50 Adjustment element / Threaded sleeve 51 External thread adjusting element 52 Point of attack / External hexagon 52' head 53 internal threads 54 external threads 55 Adjustment element / threaded stud 56 pistons 57 Connecting element 58 Slotted hole 59 Anti-rotation pin 59', 59" part 61 control cables 62 actuator control connections G1, G2 thread size K tilting axle R Exit direction / Ejection direction R', R" Direction of movement / direction S1, S2 slope T1, T2 part X-axis / Threaded axis / Actuator axis / Piezo axis

Claims

Patent claims 1. Metering valve (1) for metering a metering substance with an actuator unit (2) and a fluid unit (3), wherein the actuator unit (2) has at least one controllable actuator (4) for dispensing metering substance from the fluid unit (3), and wherein the actuator unit (2) has an adjustment mechanism (5) associated with the actuator (4) and configured for adjusting the metering valve (1), wherein the adjustment mechanism (5) has an adjusting element (50) movably mounted in a housing (20) of the actuator unit (2) by means of an external thread (51), the housing (20) comprising the actuator (4), and wherein the adjustment mechanism (5) has an adjusting element (55) movably mounted in an internal thread (53) of the adjusting element (50) by means of an external thread (54), wherein preferably a pitch (S2) of the external thread (51) differs from a pitch (S1) of the internal thread (53) of the adjusting element (55),and wherein the adjustment mechanism (5) is designed to change the position of the adjusting element (55) in the actuator unit (2).

2. Metering valve according to claim 1, wherein the adjustment mechanism (5) is configured to adjust a parameter of the actuator (4), the parameter being selected from a target position of a piezoelectric actuator (4) relative to the housing (20) of the actuator unit (2) and / or an adjust position of a movable element (30) of the metering valve (1) and / or a target stroke of the actuator (4) in operation.

3. Metering valve according to claim 1 or 2, wherein the actuator (4) is configured to move a movably mounted element (30) of the metering valve (1) towards a nozzle (38) of the metering valve (1) and / or to bring it into operative contact with a nozzle (38) of the metering valve (1), so that metering material is ejected from a nozzle opening (39) of the nozzle (38) by means of the movably mounted element (30).

4. Metering valve according to one of the preceding claims, wherein the actuator (4) comprises a piezoelectric actuator (4), and / or wherein the adjustment mechanism (5) is configured to adjust a position of a piezoelectric actuator (4) relative to the housing (20) of the actuator unit (2) and / or to adjust a piezoelectric actuator (4) in the housing (20) of the actuator unit (2).

5. Metering valve according to one of the preceding claims, wherein the adjustment mechanism (5) is configured to adjust a position of a movable element (30) of the metering valve (1) relative to a nozzle (38) of the metering valve (1) and / or to adjust a movable element (30) of the metering valve (1) in the metering valve (1), and / or wherein the metering valve (1 ) has a movement mechanism (7) with a lever (9) to transmit, in particular translate, a deflection of the actuator (4), preferably a piezoelectric actuator (4), by means of the lever (9) to a movably mounted element (30) of the metering valve (1 ).

6. Metering valve according to one of the preceding claims, wherein the adjustment mechanism (5) is configured to adjust a movable element (30) of the metering valve (1) such that the movable element (30), in particular a tip (37), is pressed into a nozzle (38) of the metering valve (1) with a defined force in a deflected operating state of the actuator (4).

7. Metering valve according to one of the preceding claims, wherein the actuator (4) comprises a pneumatic actuator, and / or wherein the adjustment mechanism (5) is configured to set a position of a stroke limit for a pneumatic actuator and / or for a movable element (30) of the metering valve (1) relative to the housing (20) of the actuator unit (2), and / or to adjust a stroke limit for a pneumatic actuator and / or for a movable element (30) of the metering valve (1) in the housing (20) of the actuator unit (2).

8. Metering valve according to one of the preceding claims with at least two actuators (4) which, in operation, exert a tilting moment at different locations on a lever rotatably mounted about a tilting axis, wherein preferably the actuators (4) are positioned at an angle to each other, and wherein the adjustment mechanism (5) is designed to adjust a position of at least one actuator (4) relative to the housing (20) of the actuator unit (2) and / or to adjust the at least one actuator (4) in the housing (20) of the actuator unit (2).

9. Metering valve according to one of the preceding claims, wherein a pitch (S2) of the external thread (51) of the adjusting element (50) is greater than a pitch (S1) of the internal thread (53) of the adjusting element (50), or wherein optionally a pitch (S2) of the external thread (51) of the adjusting element (50) is less than a pitch (S1) of the internal thread (53) of the adjusting element (50), and / or wherein a pitch (S2) of the external thread (51) of the adjusting element (50) is less than a pitch of a standardized fine thread of the same nominal size, or wherein optionally a pitch (S2) of the external thread (51) of the adjusting element (50) is equal to a pitch of a standardized fine thread of the same nominal size.

10. Metering valve according to one of the preceding claims, wherein the pitch difference between the external thread (51) of the adjusting element (50) and the internal thread (53) of the adjusting element (50) is 0.1 mm or less, preferably at most 0.05 mm, more preferably at most 0.04 mm, more preferably at most 0.03 mm, in particular 0.025 mm to 0.01 mm.

11. Metering valve according to one of the preceding claims, wherein at least one thread (51, 53, 54) of the adjustment mechanism (5) comprises at least one of the following materials: stainless steel, electropolished stainless steel, hardened or surface-hardened stainless steel, electropolished and hardened or surface-hardened stainless steel, cold-worked stainless steel, stainless steel with a carbonitrided or nitrided surface, hardened carbon steel with or without a carbonitrided or nitrided surface, hardened tool steel, Hard metal ceramics Coating to increase surface hardness and / or reduce the coefficient of friction.

12. Metering valve according to one of the preceding claims, wherein the adjustment mechanism (5) is designed such that the adjusting element (50) and the adjusting element (55) are movable in an axial direction (R') relative to each other, wherein a direction of movement (R') is parallel to an outlet direction (R) of metering material and / or parallel to a threaded axis of the adjustment mechanism (5), wherein preferably the direction of movement (R') is along a longitudinal direction of a piezoelectric actuator (4).

13. Metering valve according to one of the preceding claims, wherein the adjustment mechanism (5) has an anti-rotation device (58, 59) for the adjusting element (55), wherein the anti-rotation device (58, 59) comprises an elongated hole (58) in the adjusting element (55) into which an anti-rotation pin (59) engages, wherein preferably the elongated hole (58) is along an axial direction of movement (R') of the adjusting element (50) and the adjusting element (55), and / or wherein an anti-rotation device (58, 59) of the adjustment mechanism (5) has an anti-rotation pin (59) which is designed to limit an adjustment range of the adjustment mechanism (5).

14. Actuator unit (2) for a metering valve (1) for metering a metering substance according to one of the preceding claims, which actuator unit (2) is coupleable with a fluidics unit (3), wherein the Actuator unit (2) has at least one controllable actuator (4) for dispensing metering material from the fluid unit (3), and wherein the actuator unit (2) has an adjustment mechanism (5) associated with the actuator (4) and designed for adjusting the metering valve (1), wherein the adjustment mechanism (5) has an adjusting element (50) movably mounted in a housing (20) of the actuator unit (2) by means of an external thread (51), the housing (20) comprising the actuator (4), and wherein the adjustment mechanism (5) has an adjusting element (55) movably mounted in an internal thread (53) of the adjusting element (50) by means of an external thread (54), wherein preferably a pitch (S2) of the external thread (51) differs from a pitch (S1) of the internal thread (53) of the adjusting element (50), and wherein the The adjustment mechanism (5) is designed to change the position of the adjusting element (55) in the actuator unit (2).

15. Method for adjusting a metering valve (1) for dispensing a metering substance with an actuator unit (2) and a fluid unit (3), wherein the actuator unit (2) has at least one controllable actuator (4) for dispensing metering substance from the fluid unit (3), and wherein the actuator unit (2) has an adjustment mechanism (5), wherein the adjustment mechanism (5) is associated with the actuator (4) and is configured for adjusting the metering valve (1), wherein the adjustment mechanism (5) has an adjusting element (50) which is rotated by means of an external thread (51) in a housing (20) of the actuator unit (2), the housing (20) comprising the actuator (4), and wherein the adjustment mechanism (5) has an adjusting element (55) which is movably mounted in an internal thread (53) of the adjusting element (50) by means of an external thread (54).wherein preferably a pitch (S2) of the external thread (51) differs from a pitch (S1) of the internal thread (53) of the adjusting element (50), wherein a position of the adjusting element (55) in the actuator unit (2) is changed by means of the adjustment mechanism (5), wherein optionally the adjusting element (50) and the adjusting element (55) are rotated simultaneously and by the same amount, or wherein optionally the adjusting element (55) is mounted in a rotationally secure manner while the adjusting element (50) is rotated in the actuator unit (2).

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