Fluid instrument

Abstract

The invention relates to a fluid device having at least one valve unit and at least one suction unit, each having a fluid chamber for receiving a fluid, which is fluidically connected to one another via at least one connecting channel, at least one supply channel leading into the fluid chamber of the valve unit, the valve unit and the back-suction unit each comprise an actuation device, and wherein the valve unit and the back-suction unit each comprise an actuation device, and wherein the valve unit and the back-suction unit each comprise an actuation device, the associated valve diaphragm or the suction diaphragm can be adjusted by the actuating device in the sense of a change in the volume of the associated fluid chamber, a fluid connection can be established between the supply channel and the connecting channel by the valve diaphragm, and the valve diaphragm or the suction diaphragm can be adjusted by the actuating device in the sense of a change in the volume of the associated fluid chamber. There is a permanent fluid connection between the connecting channel and the output channel via the fluid chamber of the back-suction unit.

Description

Technical Field

[0001] The present invention relates to a fluid device having at least one valve unit and at least one back-sucking unit, wherein the valve unit and the back-sucking unit each have a fluid chamber configured to receive a fluid. Background Art

[0002] Such fluid devices (also called suction / return units) have long been known, for example from JP H03-12917. Therein is described a fluid device which is used in the production of semiconductors and which offers the possibility of sucking back fluid located in a fluid channel in order to avoid undesired dripping at the outlet opening. The suck-back effect can be caused by a negative pressure which can be generated in a fluid chamber of the fluid device, to which the fluid channel is connected. The fluid chamber is delimited by an elastically deformable membrane.

[0003] A fluid device is also known from DE 10 2020 209 594 B3, in which a diaphragm can be actuated by means of a piezoelectric actuator. Summary of the invention

[0004] The object of the present invention is to provide a fluid device of the type mentioned at the outset which is of simple and compact construction and can be operated reliably.

[0005] This object is achieved by a fluid device having the features of independent claim 1. Developments of the invention are indicated in the dependent claims.

[0006] The fluid apparatus according to the present invention comprises at least one valve unit and at least one back-suction unit, wherein the valve unit and the back-suction unit respectively comprise a fluid chamber configured to receive a fluid, wherein the fluid chambers are fluidically connected to each other via at least one connecting channel, wherein at least one supply channel opens into the fluid chamber of the valve unit, and an output channel opens into the fluid chamber of the back-suction unit, and wherein the fluid chambers are respectively bounded by elastically deformable diaphragms, and wherein the valve unit and the back-suction unit respectively comprise an operating device, via which an associated valve diaphragm or back-suction diaphragm can be adjusted in the sense of a volume change of the associated fluid chamber, wherein a fluid connection can be established between the supply channel and the connecting channel via the valve diaphragm, and a permanent fluid connection exists between the connecting channel and the output channel via the fluid chamber of the back-suction unit.

[0007] Both the valve unit and the re-sucking unit each have an elastically deformable membrane and an actuating device for the membrane. The valve unit and the re-sucking unit are therefore constructed identically in terms of essential components, which minimizes production costs. The fluidic device is suitable for performing medium separations via the valve unit, whereby the fluidic device can be used as a suction / return unit in the case of dosing or liquid handling in the semiconductor industry or in the field of medical laboratories. For example, the fluidic device is suitable for use in fluid handling with microtiter plates.

[0008] In a further development of the present invention, the valve membrane and the back-sucking membrane are arranged in membrane planes parallel to each other. Suitably, the valve unit and the back-sucking unit are arranged one after the other in the arrangement direction, wherein the valve membrane and the back-sucking membrane are also arranged one after the other in the arrangement direction.

[0009] In a particularly preferred manner, the valve membrane and the suction return membrane are designed identically.

[0010] The material of the membrane is suitably determined depending on the medium with which the membrane comes into contact, for example thermoplastics such as polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer (PFA) or fluororubber (FKN).

[0011] In a development of the invention, the diaphragm centers of the valve diaphragm and of the return suction diaphragm lie on a common diaphragm axis.

[0012] In a particularly preferred manner, the fluid device has a base plate with a mounting surface, at which the valve unit and the back-sucking unit are arranged and fixed by means of fixing means. However, it is also conceivable in principle to use a fluid device without such a base plate.

[0013] In a particularly preferred manner, the membrane planes of the valve membrane and the back-sucking membrane are oriented perpendicularly to the mounting surface. It is therefore possible to arrange at least one valve unit and at least one back-sucking unit one after the other in the arrangement direction on the mounting surface, wherein the membrane planes of the respective valve unit or back-sucking unit are then also oriented perpendicularly to the mounting surface one after the other in the arrangement direction. This design is particularly space-saving.

[0014] In a development of the invention, the base plate has at least one feed opening for supplying the fluid and is provided with an outlet opening for discharging the fluid, wherein a fluid channel system extending between the feed opening and the outlet opening communicates with channels in the valve unit and the back-sucking unit.

[0015] In a development of the invention, the outlet opening is formed on an outlet nozzle which is arranged on the base plate and belongs to the fluid device.

[0016] It is possible for the supply channel opening of the supply channel of the valve unit and the connecting channel opening of the connecting channel to be arranged on the same side of the valve unit, preferably on the underside of the valve unit facing the mounting surface.

[0017] Furthermore, it is possible that the connecting channel opening of the communication channel of the back-sucking unit and the outlet channel opening of the outlet channel are arranged on the same side on the back-sucking unit, preferably on the lower side of the back-sucking unit facing the installation surface.

[0018] In a further development of the invention, the fluid chambers of the valve unit and of the back-sucking unit have the same diameter. In a particularly preferred manner, the actuating device of the valve unit and the actuating device of the back-sucking unit are constructed identically. This leads to a reduction in manufacturing costs, since the components of the actuating device can be manufactured independently of the type of unit in which the components of the actuating device are later used.

[0019] In a development of the invention, the actuating device has an actuating drive and an actuating mechanism connected to the diaphragm, so that an actuating movement transmitted from the actuating drive to the actuating mechanism causes the actuating mechanism to assume different positions in order to elastically deform the associated diaphragm in such a way that a volume change of the fluid chamber is caused.

[0020] In a development of the invention, the actuating mechanism is designed as an actuating lever, in particular of plate-like design, which is fixedly clamped on one side via a lever support, is coupled to an associated diaphragm via a driver element, and is coupled at its free lever end to an actuating drive in such a way that an actuating movement transmitted by the actuating drive causes a pivoting of the actuating lever. The actuating device is therefore designed overall to be relatively simple and therefore not susceptible to interference.

[0021] In a particularly preferred manner, the actuating drive is designed as an electric actuating drive, in particular as a stepper motor or a direct current motor.

[0022] In a particularly preferred manner, the longitudinal axis of the handling device is designed parallel to the installation surface. Thus, in the operating state, the handling device is oriented transversely, whereby the overall height of the fluid device can be kept relatively low.

[0023] In a development of the invention, the actuating drive has an output shaft which is rotationally driven about the rotation axis and is coupled to an eccentric element which is arranged eccentrically to the rotation axis and is coupled to the actuating lever, in particular to its free lever end.

[0024] In a development of the invention, a restoring element is assigned to the actuating member for restoring the actuating member and the coupled diaphragm in the sense of a reduction in the volume of the associated fluid chamber.

[0025] In a particularly preferred manner, the restoring element is configured as a spring, in particular a leaf spring. Suitably, the leaf spring is supported at its two ends on the cover.

[0026] In a development of the invention, the fluid chamber of the valve unit has a channel in the form of a raised peak, which forms a valve seat that can be closed by an associated valve membrane.

[0027] In a development of the invention, a travel sensor is provided for determining the travel of the actuating lever.

[0028] In a particularly preferred manner, the travel sensor is associated with the free lever end of the actuating lever and measures the travel of the lever end of the actuating lever.

[0029] It is possible to adjust the travel of the actuating lever via a travel sensor in the sense of adjusting to a sensor signal, wherein a specific voltage signal is associated with a specific opening position. If a predefined sensor signal or voltage signal is not reached, this indicates that the desired opening position has not been reached. It is then possible to adjust again until the desired opening position is reached.

[0030] In a development of the invention, the fluid device has a housing which carries all components.

[0031] It is possible for the fluid chambers of the valve unit and of the back-suction unit to be formed in a fluid body which is to be easily integrated into the housing so that, for example, the back-suction unit can be easily formed from the valve unit by exchanging the fluid body. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] A preferred embodiment of the present invention is shown in the drawings and is explained in more detail below. In the drawings:

[0033] Figure 1 A perspective view showing a preferred embodiment of the fluidic device according to the present invention when used at a microtiter plate,

[0034] Figure 2 Show Figure 1 A perspective view of a fluidic apparatus without a microtiter plate,

[0035] Figure 3 Shown in Figure 1 and Figure 2 A perspective view (partially as an exploded view) of a valve unit or a suck-back unit for use in a fluid apparatus of

[0036] Figure 4 Show Figure 3 Exploded view of a valve unit or a back-suction unit, wherein Figure 3 Compared to the view showing the other side of the housing,

[0037] Figure 5 Shown in Figure 1 and Figure 2 A partial cross-sectional view of a valve unit without a housing used in a fluid device,

[0038] Figure 6 Shown along Figure 5 The line VI-VI passes through Figure 5 The cross section of the valve unit,

[0039] Figure 7 Shown along Figure 6 The line VII-VII passes through Figure 6 Horizontal cross section of the valve unit,

[0040] Figure 8 Shown with Figure 6 The cross-section similarity in Figure 5 A cross section of a valve unit, wherein the actuating element occupies another position,

[0041] Fig. 9 Shown with Figure 6 A cross section similar to that in FIG. 1 , wherein a back-suction unit is shown here instead of a valve unit,

[0042] Fig.10 Shown through Fig. 9 The cross section of the suction unit, in which the actuating lever occupies Fig. 9 Compared to the different positions shown in

[0043] Fig.11 Shown along Fig.10 The line XI-XI in passes through the horizontal section of the suck-back unit, and

[0044] Fig.12 Shown through Fig. 9 and Fig.10 Longitudinal section through a suction back unit, wherein the actuation lever is in another position. DETAILED DESCRIPTION

[0045] Figures 1 to 12 FIG. 1 shows a preferred embodiment of a fluid device 11 according to the present invention. In the following, the fluid device 11 is used as a metering device for a liquid medium by way of example. Figure 1 As shown by way of example in FIG. 1 , the fluidic device can be used in the field of medical laboratories for fluid handling with microtiter plates 12 . This application is purely exemplary.

[0046] In the illustrated application, a microtiter plate 12 is therefore provided, which is illustrated by way of example in the form of a 96-well microtiter plate, which therefore has 96 cavities 13. The fluidic device 11 has the task of dispensing a certain amount of liquid into selected cavities of the cavities 13. Of course, microtiter plates 12 of completely different dimensions can also be used.

[0047] In any case, the task of the fluid device 11 is to meter a certain amount of liquid into the relevant cavity 13. Since this is usually a relatively small amount, especially in the microliter range, there is a need to meter the amount accurately. Undesired dripping at the outlet opening 22 of the fluid device 11 must be avoided.

[0048] For this purpose, the fluid device 11 has at least one valve unit 14 and at least one back-sucking unit 15. As described in more detail below, the valve unit 14 ensures that a fluid passage can be selectively opened or closed, in particular in the region of the valve seat, wherein, when the fluid passage is open, the fluid to be metered (thus, in the example, a liquid) can reach the outlet opening 22 and be dispensed there into the associated cavity 13. The associated back-sucking unit 15 generates a back-sucking effect by means of negative pressure when it is actuated, whereby the fluid still in the fluid passage is sucked back in order to prevent the negative effects of the undesired dripping described above.

[0049] In the exemplary case shown, the fluid device 11 consists of a single valve unit 14 and a single back-sucking unit 15, which are arranged in an arrangement direction 16 ( Figure 2 Of course, it is possible to use a plurality of valve units and a plurality of back-suction units, wherein in this case the corresponding valve unit is also assigned one of the back-suction units.

[0050] In the example shown, the fluid device 11 has, in addition to the valve unit 14 and the back-sucking unit 15 , a base plate 17 which has a mounting surface 18 on the top and an outlet connection 19 on the bottom.

[0051] As especially in Figure 1 and Figure 2 As shown in the figure, the valve unit 14 and the back-sucking unit 15 are fixed to the mounting surface 18 of the base plate 17 by means of a fixing device 20. In the example shown, a screw connection is selected between the valve unit 14 or the back-sucking unit 15 and the base plate 17, but it is also possible to use other types of fixing devices, such as a latch, snap or clip connection that can be operated without tools.

[0052] As especially in Figure 2As shown in FIG, the bottom plate 17 has at least one feed opening (not shown) for supplying a medium or fluid, in the example case a liquid. Figure 2 As shown in , a supply line 99 is arranged at the feed opening, and the supply line is exemplarily configured as a supply hose. For example, the supply hose can be connected to the feed opening by means of a hose connection.

[0053] It is possible that the arrangement direction 16 is not in Figure 2 Rather than running essentially parallel to the supply line 99 as shown in , they run perpendicularly thereto, for example if a minimum grid size parallel to the supply line 99 is required.

[0054] The base plate 17 also has an outlet opening (not shown) for the fluid at the lower outlet connection 19. Between the feed opening and the outlet opening, a fluid channel system (not shown) extending in the base plate communicates with channels in the valve unit 14 and the back-sucking unit 15.

[0055] So external Figure 2 As shown in FIG, an outlet nozzle 21 is arranged at the outlet opening at the outlet interface 19 on the lower side of the bottom plate 17, and the outlet nozzle is fluidically connected to the outlet opening. A fluid channel (not shown) extends through the outlet nozzle 21, which ends at an outlet opening 22 arranged at the free end of the outlet nozzle 21.

[0056] As especially Figure 4 , Figure 5 , Figure 6 and Fig.10 As can be seen from the overview, the valve unit 14 and the back-sucking unit 15 each have a fluid chamber 23 , 24 .

[0057] As especially in Figure 3 , Figure 4 and Figure 5 As shown in FIG. 1 , the fluid chambers 23 , 24 are each formed in a fluid body 25 , 26 , which in turn are each a component of a valve unit housing 27 or a back-suction unit housing 28 .

[0058] An important aspect of the invention is that the fluid chambers 23, 24 are each delimited by an elastically deformable membrane 29, 30. Thus, in the case of the valve unit 14, the valve membrane 29 delimits the fluid chamber 23 of the valve unit 14, and in the case of the back-sucking unit 15, the back-sucking membrane 30 delimits the fluid chamber 24 of the back-sucking unit 15.

[0059] Another essential aspect of the invention is that, apart from the design of the fluid chambers 24 , 25 , the valve unit 14 on the one hand and the back-sucking unit 15 on the other hand are designed identically.

[0060] Therefore, apart from the structure of the fluid chambers 23 , 24 , the structure of the valve unit 14 described below also applies to the suck-back unit 15 .

[0061] The valve unit 14 thus has the valve unit housing 27 already mentioned. In the present example, the valve unit housing 27 is of cuboid design. The valve unit housing has a front side 31 and a back side 32 lying opposite the front side 31. Furthermore, the valve unit housing has an upper side 33 and a lower side 34 lying opposite the upper side, which in the assembled state of use rests on the mounting surface 18 of the base plate 17. Finally, the valve unit housing 27 has two end sides 35, 36 arranged opposite one another.

[0062] For example, in order to fix the valve unit housing 27 to the equipment surface 18, a fixing flange 37 extending outward from the end side 35 can be provided, wherein a further fixing flange 38 is provided at the opposite end side 35, but the further fixing flange is not constructed as a protrusion, but is constructed as a cutout constructed at the front side 31 at the front edge of the valve unit housing 27.

[0063] As especially Figure 3 As shown in FIG, the fixing flanges 37, 38 each have a through-drilling (not shown), through which a fixing screw fastener 39 is passed, which in turn is screwed into a corresponding screw hole on the base plate 17. In this way, the valve unit 14 is fixed to the mounting surface 18 of the base plate 17.

[0064] An important aspect is that the already mentioned fluid body 25 is also fastened to the valve unit housing 27 as a separate component.

[0065] As already mentioned, the fluid chamber 24 of the valve unit 14 is formed in a fluid body 25 of the valve unit 14 .

[0066] As especially Figure 3 , Figure 6 and Figure 7 As can be seen from the overview of FIG, the fluid body 25 of the valve unit 14 is designed in an L-shape and has a base section 40 and an edge section 41 protruding at a right angle from the base section. The edge section 41 forms part of the underside 34 of the valve unit 14. The strip-shaped edge section 41 has two fixing flanges 37, 38 arranged on its left and right sides on the side.

[0067] The fluid chamber 23 formed in the fluid body 25 of the valve unit 14 has a substantially circular cross section, with a strip-shaped raised peak extending radially inwards into the center. 42 is interrupted, and a supply channel 43 extends in the raised peak. The supply channel 43 extends from a supply channel opening 44 configured at the strip-shaped edge section 41 into the center of the fluid chamber 23, wherein a base channel section 45 of the supply channel 43 is oriented substantially perpendicular to the installation surface 18. A seat channel section 46, which is configured relatively short in the embodiment, is placed substantially at a right angle to the base channel section 45 and leads to the fluid chamber 23 via a valve seat opening 47. As particularly Figure 6 As shown in FIG. 4 , the valve seat opening 47 is located on a valve seat 48 which is designed, in particular, in a conical manner and is part of an inwardly projecting raised peak 42 .

[0068] So external Figure 6 and Figure 8 As shown in the figure, the valve seat 48 is matched with the valve membrane 29, which can selectively open or close the valve seat opening 47 in a manner explained in more detail below. When the valve seat opening 47 is open, the fluid can flow into the fluid chamber 23 of the valve unit 14 via the supply channel 43. In contrast, when the valve seat opening 47 is closed, the supply of fluid to the fluid chamber 23 is blocked.

[0069] The supply of the fluid takes place via the already mentioned supply line 20 which is connected to the base plate 17. The fluid then reaches the supply channel opening 44 of the valve unit via the channel system in the base plate 17.

[0070] As especially in Figure 7 , another channel, namely the connecting channel 50, opens into the valve chamber 23 of the valve unit 14. However, unlike the supply channel 43 described above, the connecting channel 50 does not open into the fluid chamber 23 via the central raised peak 42, but at the peripheral surface 51 of the fluid chamber 23. The connecting channel 50 extends from a connecting channel opening 52 formed at the edge section 41 of the fluid body 25 in the direction toward the fluid chamber 23 and opens into the fluid chamber 23 via an opening 53 there.

[0071] It is of course possible to interchange the supply channel 43 and the connecting channel 50 , ie the fluid supply takes place via the connecting channel 50 , which then serves as the supply channel.

[0072] So external Figure 7As shown in , two of the previously described channels, namely the supply channel 43 and the connecting channel 50, both open at the strip-shaped edge section 41, that is, the channels open at the lower side 34 of the valve unit 14. As described above, the valve unit 14 is assembled so that the lower side 34 of the valve unit 14 and therefore the strip-shaped edge section 41 are in contact with the mounting surface of the base plate 17. Openings (not shown) that are connected to the supply channel 43 and the connecting channel 50, in particular to the supply channel opening 44 and the connecting channel opening 42, are constructed on the mounting surface of the base plate 17. There is a need for sealing at the interface between the valve unit 14 and the base plate 17, which is sealed by, for example, Figure 7 The sealing ring 54 shown by way of example is formed.

[0073] As especially Figure 3 As shown in FIG, the fluid body 25 of the valve unit 14 is a component separate from the valve unit housing 27 and is therefore fixed to the valve unit housing 27 via suitable fixing means 55. For example, a screw connection between the fluid body 25 and the valve unit housing 27 is suitable for this.

[0074] For example, it is possible to construct a plurality of fixing holes 56 , for example four fixing holes in number, at the base section 40 of the fluid body, through which corresponding fixing screw fasteners 57 are passed, which in turn are screwed into corresponding screw holes (not shown) at the valve unit housing 27 .

[0075] The fluid body 25 is generally a component in which the fluid chamber 23 is identically constructed during manufacture. The material of the fluid body depends on the type of fluid or medium used to be dosed via the fluid device 11. The fluid body is preferably a plastic component, wherein, in the case of laboratory applications, polyetheretherketone (PEEK) is used as the fluid body material, while in semiconductor applications, a fluid body composed of polytetrafluoroethylene or perfluoroalkoxy polymer (PFA) is more likely to be used.

[0076] As mentioned above and exemplarily in Figure 6 and Figure 8 As shown in FIG. 2 , the fluid chamber 23 of the valve unit 14 is delimited by a valve membrane 29 .

[0077] As especially Figure 6 In and also Figure 8 As shown in FIG, the valve membrane 29 is inserted into the valve unit housing 27, in which the annular membrane edge section 58 formed in a ridge-like manner is inserted into an annular groove 59 formed on the valve unit housing for this purpose. The valve membrane 29 is then tensioned by fixing the fluid body 25, and the membrane edge section 58 is thus clamped between the fluid body 25 and the valve unit housing.

[0078] Except Figure 6 As shown in FIG. , the valve membrane 29 has a membrane center 60 which is associated with the valve seat 58 and can close the valve seat opening 47 or open it in a manner described below. A fixing interface 61 is located at the membrane center 60 on the back side, that is, facing away from the fluid chamber 24, via which the valve membrane 29 is coupled to an associated actuation device 62. The actuation device 62 serves to actuate the valve membrane 29, thereby, in addition to opening and closing the valve opening 40, also resulting in a change in the volume of the associated fluid chamber 23.

[0079] The actuating device 62 has an actuating drive 63 and an actuating mechanism 64 connected to the valve diaphragm 29, so that an actuating movement transmitted from the actuating drive 62 to the actuating mechanism 64 causes the actuating mechanism 64 to assume different positions so as to elastically deform the corresponding valve diaphragm in a manner that causes a volume change in the fluid chamber 23.

[0080] As especially Figure 4 , Figure 5 and Figure 6 As can be seen from the overview of FIG. 6 , in the exemplary case shown, the actuating drive 63 is an electric actuating drive in the form of a stepper motor or a DC motor. The actuating drive 63 has a drive housing 65 in which components of the electric actuating drive (not shown in greater detail here) are accommodated. Figure 4 As shown in FIG. 2 , the drive housing 65 is fastened to one of the end faces 35 of the valve unit housing 27 . The actuating drive 63 further comprises an output shaft 67 rotatably driven about an axis of rotation 66 , which is coupled to an eccentric element 68 arranged eccentrically to the axis of rotation 66 .

[0081] As especially Figure 5 As shown in FIG. 6 , the eccentric element 68 is designed as an eccentric pin, which is arranged on the end side of the output shaft 67 .

[0082] So external Figure 6 As shown in , the driven shaft 67 is rotatably supported in the valve drive housing via a rolling bearing 69, wherein the rolling bearing 69 is arranged between a cover 70 described in more detail below and a bearing part of the valve unit housing 67, in particular pressed therein. A further rolling bearing 71 is arranged on the eccentric element 68, which has a significantly smaller diameter than the previously described drive shaft rolling bearing 69. This eccentric rolling bearing 71 is connected to the actuating mechanism 64. As in particular Figure 5, an output shaft 67 projects from a drive housing 65, wherein a bearing element 72 is arranged between the drive housing and the output shaft rolling bearing 69, via which the actuating drive is supported on the previously described end side 35 of the valve unit housing 27, such that the end side has a slot 73 open toward the upper side of the valve unit housing 67, so that the housing region is divided into two clamping fingers in the region of the end side 35, each of which has an arc-shaped recess (not shown) and thus accommodates the bearing element 72 associated with the output shaft between them. The clamping fingers can be moved toward each other by means of a clamping screw 74 (introduced from the front side or rear side of the valve unit housing 27 into a clamping bore formed in one of the clamping fingers and screwed to the other clamping finger), whereby clamping occurs at the bearing element 72 and thus the actuating drive is locked at the valve unit housing 27.

[0083] As already mentioned above, the actuating device 62 has an actuating mechanism 64, which in the example is configured as an actuating lever. The actuating lever is plate-shaped and has a relatively long lever base section 75, wherein an actuating surface 77 directed toward the fluid chamber is configured in the region of the free lever end 76 and contacts the eccentric rolling bearing 71.

[0084] As especially Figure 4 As shown in FIG, the free lever end 76 (which simultaneously forms the end of the lever base section 75 in which a lever strap 79 oriented transversely to the longitudinal axis 78 of the actuating lever is formed) forms an actuating surface 77 on its underside.

[0085] The actuating lever is also fixedly clamped at its other lever end 80, which is oriented opposite the free lever end 76, via a lever support 81. For this purpose, the actuating lever is bent at the other lever end 80 and engages in a groove-shaped recess on the valve unit housing 27, where the actuating lever is then fixedly clamped.

[0086] An important aspect is that the actuating mechanism 64, in this example the actuating lever, is coupled to the valve membrane 39. For this purpose, the actuating lever has a coupling interface 82 in the region of its lever base section, which has a through-hole 83 formed in the lever base section 75. The through-hole 83 is penetrated by a coupling pin 84, which in turn is designed in the shape of a hammer head on the underside and is therefore part of the fixing interface 61 between the coupling pin 84 and the valve membrane 29.

[0087] For example, in Figure 6 As shown in FIG. 1 , the valve diaphragm 29 has a pin-shaped portion 85 ( Figure 8 and 12), which has a central recess, in which the hammerhead-shaped section of the connecting pin 64 is arranged in the manner of a groove and key.

[0088] This ensures that an actuating movement acting on the actuating lever, which is exerted by the actuating drive 62 , is transmitted to the valve membrane 29 .

[0089] As especially Figure 4 As shown in FIG. 8 , a restoring element 86 is associated with the actuating member 64 for restoring the actuating member 64 and the coupled valve membrane 29 in the sense of a reduction in the volume of the associated fluid chamber 23 .

[0090] In this example, the restoring element is designed as a leaf spring. Figure 6 As shown in , the leaf spring is connected to the coupling pin 84 so that the leaf spring has a through hole 87 in the center and is placed with the through hole 87 on a support pin-shaped portion that protrudes upward at the upper side of the coupling pin 84. The leaf spring has an arched portion, wherein the region of the leaf spring with the through hole 87 is arranged closer to the fluid chamber than the two mutually opposite spring ends, which are respectively supported on the inner side of the cover 70 mentioned above. By this arrangement, the diaphragm is pressed into the normally closed position, in which the valve seat opening 87 is closed by the diaphragm. Therefore, in order to open the valve seat opening 47, work must be done against the spring force of the leaf spring.

[0091] The cover 70 already mentioned above has several tasks. On the one hand, it supports the leaf spring on the underside and on the other hand it closes the fluid body 25 at the end. As a type of fastening for the cover, a screw connection is also provided.

[0092] So external Figure 4 As shown in FIG. 8 , an electronic component 89 is arranged on the end side 35 , on which the actuation drive 63 is also formed.

[0093] An important aspect is that the actuating lever is assigned a travel sensor 90 for determining the travel of the actuating lever. The travel sensor 90 is assigned to the free lever end 76 of the actuating lever and measures the travel of the lever end of the actuating lever.

[0094] The lever strap 79 described above also serves to provide a relatively large measuring surface for the travel sensor 90. The travel sensor 90 is designed for contactless measurement of the travel of an actuating lever, for example an inductive travel sensor can be used.

[0095] As especially Figure 4In addition, a covering cap 91 is provided for covering the actuating drive 63 and the electronic components or elements 89 arranged at the end side 35. A voltage supply for the actuating drive 63 can be established via the covering cap 91, for example via a through-conducting opening arranged at the end side of the covering cap.

[0096] As already mentioned, the back-sucking unit 15 is constructed identically to the valve unit 14 except for the different designs of the fluid body 26 and the fluid chamber 24. Therefore, all components of the valve unit 14 are also accommodated in the back-sucking unit 15, so that they do not need to be explained again here.

[0097] As especially in Fig.10 As can be seen in the figure, the fluid chamber 24 of the back-suction unit is not penetrated by a strip-shaped raised peak. The cross-section of the fluid chamber 24 of the back-suction unit 15 is circular. The output channel 93 leads into the fluid chamber 25 of the back-suction unit 15. The output channel 93 extends between the output channel openings 94 at the edge section 41 of the fluid body 26 to a first access opening 95 in the area of ​​the peripheral wall 92 of the fluid chamber 24. As already mentioned, the valve unit 14 and the back-suction unit 15 are connected to each other via a connecting channel 50. The connecting channel in the back-suction unit 15 extends from the connecting channel opening 96 at the edge section 41 of the fluid body 26 to a second access opening 97. It is feasible that, as Fig.10 As shown in the figure, the channel oriented centrally in the direction of the center of the fluid chamber 24 serves as the output channel 93, and the other channel eccentric to this arrangement serves as the connecting channel, but it is also conceivable to set the central channel as the connecting channel and the channel eccentric to this arrangement as the output channel.

[0098] An important aspect is that in the back-sucking unit 15 there is a permanent fluid connection between the connecting channel 50 and the outlet channel 93. Therefore, the back-sucking membrane 30 associated with the fluid chamber 24 is only used to establish a volume increase or volume reduction. When the volume increases, a negative pressure is generated in the fluid chamber 24, which sucks the medium back into the fluid chamber 24 via the outlet channel, thereby preventing undesired dripping in the area of ​​the outlet opening 22 of the outlet nozzle 21.

[0099] The function of the fluidic device as a dosing device in combination with the microtiter plate 12 can be described as follows:

[0100] First, the fluid device is arranged with its outlet nozzle 21 over the cavity 13 to be filled. In this position, the valve membrane rests on the valve seat 28, so that the valve seat opening 47 is closed. For metering, the actuating drive is then subsequently activated, whereby the eccentric element 68 is moved in the clockwise direction via the rotational movement of the output shaft. This movement of the eccentric element 68 acts on the free lever end 76 of the actuating lever, which itself is pivoted to the left. Figure 8. In this case, the coupled valve membrane 29 is lifted from the valve seat 48, and the fluid or medium to be dispensed or metered reaches the fluid chamber 23 of the valve unit 14 via the supply channel. From there, the fluid to be metered returns to the base plate 17 via the connecting channel 50, and from there via the channel system in the base plate 17 through the connecting channel 50 in the back-sucking unit 15 to the fluid chamber 24 of the back-sucking unit 15. From there, the fluid to be dispensed reaches the base plate 17 again via the outlet channel 83 of the back-sucking unit 15 and from there via the channel arranged in the outlet nozzle to the outlet opening 22, and from there is dispensed into the associated cavity 13.

[0101] It is possible to control or even regulate the amount to be metered via the opening at the valve seat opening 47. One conceivable regulation is carried out via a travel sensor 90, which measures the free lever end. In a previously performed calibration run, different openings were associated with different voltage values ​​of the travel sensor. Thus, for example, a voltage value of 5 volts can be associated with an opening of 100%.

[0102] During the metering process, the distance between the travel sensor 90 and the free lever end is then changed by the actuation of the actuating drive 63, and a voltage value is generated. For example, as long as the voltage value is not yet at the 5 volts mentioned above, a 100% opening has not yet been reached. This means that the actuating drive continues to remain in operation until the voltage value mentioned above is reached. The actuating drive 63 is then switched off.

[0103] After the amount of fluid to be metered has been administered, the back-sucking unit 15 is activated. To this end, the actuating drive of the back-sucking unit 15 is activated, whereby the driven shaft is set in a rotational motion and the eccentric element 68 is entrained. As a result, the coupled actuating lever is moved from Fig. 9 The location shown in Fig.10 Move to the position shown in Fig.12 In the position shown in Fig.12 The position of the actuating lever shown in the figure causes the back-suction membrane 30 to be responsible for the maximum volume increase of the fluid chamber, thereby generating a negative pressure, so that the fluid present in the channel in the outlet nozzle is sucked back into the fluid chamber 24 of the back-suction unit 15 via the outlet channel 93, thereby preventing re-dripping in the area of ​​the outlet opening 22 of the outlet nozzle 21. This ensures that the previously preset target filling amount can also be accurately maintained.

Claims

1. A fluid device, comprising at least one valve unit (14) and at least one back-sucking unit (15), wherein the valve unit and the back-sucking unit each have a fluid chamber (23, 24) configured to receive a fluid, the fluid chambers being fluidically connected to each other via at least one connecting channel (50), wherein: At least one supply channel (43) opens into a fluid chamber (23) of the valve unit (14), and an output channel (93) opens into a fluid chamber (24) of the back-suction unit (15), wherein the fluid chambers (23, 24) are respectively limited by elastically deformable diaphragms (29, 30), and wherein the valve unit (14) and the back-suction unit (15) respectively include an operating device (62), by means of which the corresponding valve diaphragm (29) or back-suction diaphragm (30) can be adjusted in the sense of a volume change of the corresponding fluid chamber (23, 24), wherein a fluid connection can be established between the supply channel (43) and the connecting channel (50) via the valve diaphragm (29), and a permanent fluid connection exists between the connecting channel (50) and the output channel (93) via the fluid chamber (24) of the back-suction unit (15).

2. The fluid device according to claim 1, characterized in that: The valve membrane (29) and the suction return membrane (30) are arranged in membrane planes which are parallel to each other.

3. The fluid device according to claim 1 or 2, characterized in that: The valve membrane (29) and the suction return membrane (30) are designed identically.

4. A fluid device according to any one of the preceding claims, characterized in that The diaphragm centers (60) of the valve diaphragm (29) and the return suction diaphragm (30) are located on a common diaphragm axis.

5. A fluid device according to any one of the preceding claims, characterized in that A base plate (17) having a mounting surface (18) on which the valve unit (14) and the back-sucking unit (15) are arranged and fixed by means of fixing means.

6. The fluid device according to claim 5, characterized in that: The diaphragm planes of the valve diaphragm (29) and the return suction diaphragm (30) are oriented perpendicularly to the mounting surface (18).

7. The fluid device according to any one of claims 5 or 6, characterized in that: The base plate (17) has at least one feed opening for supplying fluid and is provided with a discharge opening for the fluid, and a fluid channel system extending between the feed opening and the discharge opening is connected to channels in the valve unit (14) and the back-sucking unit (15).

8. The fluid device according to any one of claims 5 to 7, characterized in that An outlet nozzle (21) is fluidically connected to the outlet opening on the bottom plate (17), and an outlet opening (22) for discharging fluid is arranged at the free end of the outlet nozzle.

9. The fluid device according to any one of claims 5 to 8, characterized in that: The supply channel opening (44) of the supply channel (43) of the valve unit (14) and the connecting channel opening (52) of the connecting channel (50) are arranged on the same side of the valve unit (14), preferably on the lower side (34) of the valve unit (14) facing the mounting surface (18).

10. The fluid device according to any one of claims 5 to 9, characterized in that: The connecting channel opening (96) of the connecting channel of the suction back unit (15) and the output channel opening (94) of the output channel (93) are arranged on the same side of the suction back unit (15), preferably on the lower side (34) of the suction back unit (15) facing the equipment surface (18).

11. A fluid device according to any one of the preceding claims, characterized in that The fluid chambers (23, 24) of the valve unit (14) and the suck-back unit (15) have the same diameter.

12. A fluid device according to any one of the preceding claims, characterized in that The actuating device (62) of the valve unit (14) and the actuating device (62) of the back-sucking unit (15) are designed identically.

13. A fluid device according to any one of the preceding claims, characterized in that The actuating device (62) comprises an actuating drive (63) and an actuating mechanism (64) connected to the diaphragm (29, 30), such that an actuating movement transmitted from the actuating drive (63) to the actuating mechanism (64) causes the actuating mechanism (64) to assume different positions so as to cause the associated diaphragm (29, 30) to deform elastically in such a way as to cause a change in the volume of the fluid chamber (23, 24).

14. The fluid device according to claim 13, characterized in that: The actuating mechanism (64) is designed as an actuating lever, in particular of plate-like construction, which is fixedly clamped on one side via a lever support (82), is connected to an associated diaphragm (29, 30) via a driver element, and is connected at its free lever end (76) to the actuating drive (62) in such a way that an actuating movement transmitted by the actuating drive (62) causes the actuating lever to pivot.

15. The fluid device according to claim 14, characterized in that: The actuating drive (63) is designed as an electric actuating drive, in particular as a stepper motor or a direct current motor.

16. The fluid device according to any one of claims 5 to 15, characterized in that: The longitudinal axis (78) of the handling device (62) is designed parallel to the installation surface (18).

17. The fluid device according to any one of claims 14 to 16, characterized in that: The actuating drive (63) has an output shaft (67) which is driven in rotation about an axis of rotation (66) and is coupled to an eccentric element (68) arranged eccentrically to the axis of rotation (66), which is coupled to the actuating lever, in particular to its free lever end (67).

18. The fluid device according to any one of claims 13 to 17, characterized in that: The actuating member (64) is assigned a restoring element (86) for restoring the actuating member (64) and the coupled diaphragm in the sense of a reduction in the volume of the associated fluid chamber (23, 24).

19. The fluid device according to claim 18, characterized in that: The restoring element (86) is designed as a spring, in particular as a leaf spring.

20. A fluid device according to any one of the preceding claims, characterized in that The fluid chamber (23) of the valve unit (14) has a channel (42) in the shape of a raised peak, which forms a valve seat (48) that can be closed by an associated valve membrane (29).

21. The fluid device according to any one of claims 14 to 20, characterized in that A travel sensor (90) is used to determine the travel of the actuating lever.

22. The fluid device according to claim 21, characterized in that: The travel sensor (90) is associated with the free lever end (76) of the actuating lever and measures the travel of the lever end (76) of the actuating lever.

Images