EP2738386A1 - Metering pump, pump element for the metering pump and method for producing a pump element for a metering pump - Google Patents

Abstract

The pump element (1) has a cover plate (15) and a base plate (12) which is arranged in a predefined distance to the cover plate, where a coupling bar (6) is arranged between the cover plate and the base plate. The coupling bar is coupled with an actuator unit and is movable between the base plate and the cover plate. A pump membrane film (10) is arranged between the cover plate and the base plate, where the pump membrane film is connected in a central portion with the coupling bar. Independent claims are included for the following: (1) a dosing pump with a piezoelectric bending transducer; and (2) a method for manufacturing a pump element.

Description

State of the art

The present invention relates to a method for producing a pump element for a metering pump, to a corresponding metering pump and to a corresponding pump element for a metering pump.

Microdosing pumps based on silicon, such as in WO 2010/046728 A1 described, are often complex and expensive to manufacture, if at the same time the high demands on their intrinsic safety functions must be met. For example, it must be guaranteed for insulin pumps that under no circumstances can an unwanted insulin delivery occur. In addition, the high-precision delivery of the requested dosing quantities must, for example, be guaranteed in the medical sector under all circumstances. The high manufacturing costs prevent economical use of these pumps as a disposable component. The trend to produce micropumps more cost-effectively in polymer technologies is reflected in the large number of publications such as DE 102011015184 A1 or WO 2009059664 A1 again. The metering capability of these pumps for medical applications is not given. In addition, in these solutions, the actuator (for example, a piezoelectric disk) is firmly connected to the pumping membrane, so that it significantly increases the running costs when used as a disposable product. The EP1966490 B1 and the DE102008056751A1 describe metered micropump concepts that separate an actuator / control unit from a disposable pump unit. However, the former requires, in principle, such a large actuator that this concept is not suitable for wearing on the body. Even with the latter, the degree of miniaturization is limited, since it involves a three-dimensional arrangement of 3D individual components, which also have to be structured, for example, on the sides in three dimensions. Manufacturing tolerances result in certain minimum dimensions, and the piston requires a minimum length for a functioning piston guide.

Disclosure of the invention

Against this background, the present invention provides a pump element for a metering pump, furthermore a metering pump which uses this pump element and finally a corresponding method for producing the pump element for the metering pump according to the main claims. Advantageous embodiments emerge from the respective subclaims and the following description.

In the area of safe dosing of small amounts of liquid in the range of 0.01 to 100 microliters per minute (μl / min), the size of the pump element or of the dosing pump connecting the pump element to an actuator is also important. In particular, such pump elements and metering pumps are used in the field of drug dosage, for example for insulin. In addition to the size and a favorable production price can be achieved in order to use the pump element as a disposable product can. A concept of a layered membrane pump allows a very flat and compact design. In this case, stiff, structured plates with flexible films can be combined to form a pump element.

• eine Deckelplatte;
• eine Bodenplatte, wobei die Bodenplatte in einem vordefinierten Abstand zur Deckelplatte angeordnet ist;
• ein zwischen der Deckelplatte und der Bodenplatte angeordneter Koppelungsbalken, wobei der Koppelungsbalken mit einem Aktorelement koppelbar ist und zwischen der Bodenplatte und der Deckelplatte bewegbar ist;
• eine Pumpmembranfolie, angeordnet zwischen der Deckelplatte und der Bodenplatte, wobei die Pumpmembranfolie in einem zentralen Abschnitt mit dem Koppelungsbalken verbunden ist und mittels des Koppelungsbalkens mit dem Aktorelement mechanisch koppelbar ist, wobei die Pumpmembranfolie einen lateral an den zentralen Abschnitt anschließenden flexiblen Abschnitt und einen lateral daran anschließenden mit der Bodenplatte verbundenen weiteren Abschnitt aufweist und die Pumpmembranfolie ausgebildet ist, zwischen der Pumpmembranfolie und der Bodenplatte eine Pumpkammer zu schaffen.

A pump element for a metering pump is presented, wherein the pump element has the following features:

• a cover plate;
• a bottom plate, wherein the bottom plate is arranged at a predefined distance to the cover plate;
• a coupling bar disposed between the top plate and the bottom plate, the coupling bar being coupleable to an actuator element and movable between the bottom plate and the top plate;
• a pumping membrane film, disposed between the cover plate and the bottom plate, wherein the pumping membrane film is connected in a central portion with the coupling bar and mechanically coupled by means of the coupling bar with the actuator element, wherein the pumping membrane film has a laterally adjacent to the central portion of the flexible portion and a laterally thereto has subsequent connected to the bottom plate further section and the pumping membrane is formed to provide a pumping chamber between the pumping membrane membrane and the bottom plate.

A metering pump may comprise a pump element. The pump element may also be referred to as a pump chip. In this case, the pump element can be constructed from a cover plate arranged at a predefined distance to a base plate, as well as a coupling bar and pump membrane film arranged therebetween. The cover plate can, at least in sections, be arranged in a tolerance range plane-parallel to the bottom plate. The tolerance range may be a departure from a plane-parallel orientation of 30 degrees. The pumping membrane film may be connected in a central portion to a portion of the coupling beam. A, in particular concentric, another portion of the pump membrane sheets may be connected to the bottom plate. The pumping membrane sheet may have a flexible portion laterally adjacent to the central portion between the central portion and the further portion. The flexible portion may receive a deformation of the pumping membrane film due to a deliberate deflection of the coupling beam in the direction of the cover plate. The flexible portion of the pumping membrane sheet may have a stiffness that minimizes deformation due to pumping pressure and, simultaneously or alternatively, backpressure. A connection of the pumping membrane foil to the bottom plate of the pumping element can define the lateral dimension of the pumping chamber formed by the pumping membrane foil and the bottom plate. The lateral dimension of the pumping chamber may be adjusted to define the stroke volume of the pumping element. In one embodiment For example, the coupling bar and the bottom plate may have plane-parallel surfaces in the region of the pumping chamber. In this case, the pump element may be formed by displacing or sucking liquid, in particular cyclically, deflecting the membrane. For this purpose, the central portion of the pumping membrane can be connected to the coupling bar in such a way that a deflection of the coupling bar between the bottom plate and the cover plate leads to a deflection of the pumping membrane film. The pump element is designed to displace a fluid located between the pumping membrane foil and the bottom plate when the pumping membrane foil is moved towards the bottom plate by means of the coupling bar. In a plane-parallel arrangement of the bottom plate to the coupling beam can be pressed flat on the bottom plate in a movement of the coupling beam in the direction of the bottom plate, the pumping membrane film. In a plane-parallel arrangement of the bottom plate to the coupling bar can be a coupling beam facing side of the bottom plate plane-parallel to a bottom plate facing side of the coupling beam. Advantageously, the pumping chamber has no harmful volume. The coupling bar can completely cover the lateral dimension of the pumping chamber. Advantageously, the delivery volume of the pump element can be determined by the number of pump strokes, since the pumping chamber is designed to provide a constant displacement when the coupling beam is moved to stop on the bottom plate and stop on the cover plate.

The pump element presented here can be a pump element acting on the principle of a diaphragm pump, which can be combined with an actuator to form a metering pump according to the principle of a diaphragm pump. In this case, a structure in layers allow a compact, in particular flat design. In this case, the cover plate, the coupling beam, the pumping membrane film and the bottom plate can each form a layer of the pump element. By means of the two-sided stop for the coupling bar and thus for the pumping diaphragm can advantageously be achieved a constant stroke. Advantageously, the pump element has a low backpressure sensitivity because flexible pumping membrane areas are expressed by the coupling bar in the ejection cycle.

Advantageously, an embodiment of a pump element for a safe dosing small amounts of liquid (0.01 - 100 ul / min) can be used, for example for drug dosage, especially in the diabetes market. A metering pump can consist of a pump element as a disposable product (disposable) and an actuator unit (Durable). Another advantage is the high degree of miniaturization, which is important, for example, as a driver in an insulin pump. Low production costs can be achieved and additional safety functions can be integrated.

Further, in one embodiment, the coupling beam having a spring member and / or a side wall may form a center plate disposed between the top plate and the bottom plate, the spring member being configured to move the center plate to move within a tolerance range perpendicular to the main extension plane of the bottom plate and / or cover plate restrict. In this case, the side wall and the coupling bar in a tolerance range, an equal thickness, that is, an equal extension of the bottom plate in the direction of the cover plate, have. The tolerance range perpendicular to the main extension plane of the bottom plate and simultaneously or alternatively cover plate may be less than 45 degrees, in particular ideally less than 30 degrees, in particular ideally less than 15 degrees, in particular ideally less than five degrees, in particular ideally less than three degrees, in particular ideally less than one degree.

It is also advantageous if, in one embodiment, the spring element and the side wall are integrally formed as a center plate, in particular wherein a thinned portion of the center plate forms the spring element between the coupling bar and the side wall. A one-piece center plate, which comprises the side wall and the coupling bar connected via a spring element, offers in particular manufacturing advantages. The spring element can be formed by a thinned region of the middle plate.

Furthermore, at least one joining foil can be arranged between the cover plate and the bottom plate, wherein the joining foil in the region of the coupling bar has a recess at least in the size of the coupling bar. The thickness of the joining foil can increase the lifting height of the Change coupling beam or the pumping membrane film. Advantageously, the joining foil can determine the lifting height of the coupling beam or of the pumping membrane foil. Then the lifting height can correspond to the thickness of the joining film.

The delivery volume can be determined based on a number of pumping strokes, if, as already described, the pumping chamber is designed to provide a constant displacement. When the coupling bar is deflected to the bottom plate during suction on abutment against the cover plate and when ejecting to stop, a constant displacement of the pumping chamber can be achieved. Advantageously, in one embodiment, a height of a pumping stroke does not depend on the thickness of the cover plate and the thickness of the bottom plate, because these only on the facing surfaces of the center plate, in particular the side wall, and the pumping membrane film and depending on the embodiment additionally the joining film at a distance being held. If one proceeds from a constant thickness of the middle plate and the pumping membrane film and a plane-parallel arrangement of the bottom plate to the cover plate, the stroke can be defined by a thickness of the joining film. The joining film can keep the bottom plate and the cover plate at a distance to each other. Furthermore, the joining film may have a recess in the region of the coupling beam. A tolerance range in the thickness of the joining film can lead to a tolerance range in the stroke and thus to a tolerance range in the size of the pump chamber. In response to an actual thickness of the bonding foil, the lateral connection of the pumping membrane foil and the bottom plate may be adjusted in size to accommodate the stroke volume of the pumping chamber.

Furthermore, the cover plate and at the same time or alternatively the middle plate and at the same time or alternatively the base plate can be made of a thermoplastic polymer. The cover plate, the center plate and the bottom plate may be formed as rigid, structured plates. From a production point of view, it may be useful to use the cover plate, the middle plate and the bottom plate made of a thermoplastic polymer such as polycarbonate (PC), polyethylene (PE), polymethyl methacrylate (PMMA), cyclic olefin polymer (COP) or cyclo-olefin copolymers (COC). to manufacture. In this case advantageously favorable production costs can be achieved. Furthermore, the cover plate and at the same time Alternatively, the center plate and at the same time or alternatively the bottom plate, for example by injection molding, injection compression, hot stamping, laser cutting, milling, punching and / or a combination thereof are produced. Ideally, the bottom plate and at the same time or alternatively the top plate may have a thickness between 0.6 mm and 10 mm.

Furthermore, the joining foil and simultaneously or alternatively the pumping membrane foil may be made of an elastomer and simultaneously or alternatively a thermoplastic elastomer and simultaneously or alternatively a thermoplastic as an elastic membrane. With the materials mentioned, the joining film and the pumping membrane film can be manufactured inexpensively as an elastic membrane.

Furthermore, the pump element may comprise at least one check valve, in particular two non-return valves for directing a flow of a fluid in the pumping chamber. It is also favorable if the at least two non-return valves are arranged in at least one of the base plate and simultaneously or alternatively the middle plate and simultaneously or alternatively the cover plate and simultaneously or alternatively the pump membrane foil and simultaneously or alternatively the joining foil.

• Pumpenelement; und
• Aktoreinheit für eine Dosierpumpe, die ausgebildet ist, den Koppelungsbalken in einem Toleranzbereich lotrecht zur Bodenplatte und/oder Deckelplatte zu bewegen, wobei die Aktoreinheit mittels mindestens einer Aktorgabel und gleichzeitig oder alternativ mindestens eines in einer Öffnung einrastenden Dorns und gleichzeitig oder alternativ Verschweißen und gleichzeitig oder alternativ Verkleben mit dem Koppelungsbalken des Pumpenelements verbunden ist.

A metering pump is presented, the metering pump having the following features:

• Pump element; and
• Actuator for a metering pump, which is designed to move the coupling bar in a tolerance range perpendicular to the bottom plate and / or cover plate, wherein the actuator unit by means of at least one Aktorgabel and simultaneously or alternatively at least one latching in an opening mandrel and simultaneously or alternatively welding and simultaneously or Alternatively, bonding is connected to the coupling bar of the pump element.

It is also advantageous if the actuator unit is designed as a piezo bending transducer and, simultaneously or alternatively, a reluctance actuator and simultaneously or alternatively at least one electroactive polymer and simultaneously or alternatively at least one shape memory actuator and at the same time or alternatively at least one linear magnet.

The, in particular miniaturized, metering pump consists of a reusable control unit or actuator unit (actuator) and a cost-effective disposable pump element. The proposed layer structure of this pump element includes an element for mechanically coupling the pumping membrane to the actuator (coupling bar), the coupling bar also serves as stiffening of the center of the pumping membrane film to achieve a stroke volume which, despite different pressures at the inlet or outlet of the metering pump constant remains. Corresponding coupling bar can also press the flexible areas of the pumping membrane film when ejecting completely to the pump chamber floor, that is, the bottom plate. This can lead to an excellent backpressure tolerance. The layer structure as well as the combination of materials allows easy adjustment or fine adjustment of the stroke volume of the metering pump, for example by laser welding the lateral dimensions of the pumping chamber or membrane can be defined. In particular, a readjustment, for example, by laser welding is even possible even on the finished pump element: With the presented pump element dosing accuracies better than 5% can be achieved. Another advantage of the proposed pump element is the achievable with the layer structure simple production process of the pump element. It still check valves are easy to integrate. Also, a pressure sensor that does not require electrical in the pump element and therefore is inexpensive, can be easily integrated. In addition, a safety valve is very easy to integrate, which prevents free (unwanted) forward flow of the fluid under pressure in the reservoir.

Compared with known polymeric micropumps, a simple separation of actuator and pump element is possible by the approach presented here, whereby the metering pump can be produced very inexpensively and used as a disposable part. In this case, the metering pump or the pump element has a smaller, in particular flatter design of the system as known for drug dosage suitable pumps, since the flat pump element, in particular designed as a flat diaphragm pump, can be controlled by a flat piezo bending transducer (electric motors and Gears, as used in known insulin pumps have a minimum thickness), and because the actuator can engage from the side into the pump chip. Also advantageous are low running costs, since a safety function such as "outlet clogged" can be implemented without using electrical components on the pump chip. In addition, the actuator can be housed in a reusable component. The proposed dosing pump can provide a reliable coupling of (reusable) actuator and pump element. Advantageously, dirt particles on the actuator can not change the stroke. Also, the pumping membrane film is disposed inside the pump element and therefore protected from damage and contamination. Only one actuator is required for the dosing pump. Overall, a small and especially flat design can be achieved. It is also advantageous that the pumping membrane film is moved back and forth between two fixed stops and thus achieves a defined counterpressure-independent displacement volume. Thus, by counting the strokes, a calculation of the delivered dose can be made possible. Furthermore, it is possible to dispense with flow sensors. It is a cheap mass production possible (eg injection molding), since the distance between the two-sided stop for the pumping membrane film is not dependent on injection molding tolerances, or tolerances can be compensated for by selectively changing the attachment of the pumping membrane film to the bottom plate. In addition, a drug reservoir can optionally be integrated on the pump element via a flexible membrane. In this case, any medication reservoir, in particular of the design and the deformability, possible, which may be accompanied by high wearing comfort, for example, in the medical field.

• Bereitstellen von zumindest einer Bodenplatte, einer Deckelplatte, eines Koppelungsbalken und einer Pumpmembranfolie;
• Anordnen des Koppelungsbalkens und der Pumpmembranfolie zwischen der Bodenplatte und der Deckelplatte, wobei die Bodenplatte in einem vordefinierten Abstand zur Deckelplatte angeordnet ist; und
• Fügen der Bodenplatte, der Pumpmembranfolie, des Koppelungsbalkens und der Deckelplatte, um ein Pumpenelement herzustellen.

A process for producing a pump element for a metering pump is presented, the method comprising the following steps:

• Providing at least a bottom plate, a top plate, a coupling bar, and a pumping membrane foil;
• Arranging the coupling beam and the pumping membrane film between the bottom plate and the cover plate, wherein the bottom plate is arranged at a predefined distance to the cover plate; and
• Add the bottom plate, the pumping membrane foil, the coupling bar and the top plate to make a pump element.

The cover plate and at the same time or alternatively the middle plate and simultaneously or alternatively the base plate may be made of a thermoplastic polymer such as polycarbonate (PC), polyethylene (PE), polymethyl methacrylate (PMMA), cyclic olefin polymer (COP) or cyclo-olefin copolymers (COC ) are produced for example by injection molding, injection compression, hot stamping, laser cutting, milling, punching or a combination thereof. The pumping membrane film can be made of an elastomer and, at the same time or alternatively, a thermoplastic elastomer and, at the same time or alternatively, a thermoplastic. The bottom plate and the cover plate can be arranged plane-parallel in a tolerance range at a predefined distance, wherein between the bottom plate and the cover plate of the coupling bar and the pumping membrane film are arranged. In this case, the coupling bar can be arranged in a tolerance range plane-parallel to the bottom plate. The pumping membrane foil can be placed between the coupling bar and the bottom plate. In the step of joining, the pumping membrane film is joined to the coupling bar. The pump membrane film is further joined to the bottom plate. As a joining method, in particular with the pumping membrane film, for example, laser welding can be used. The bottom plate can be connected to the cover plate, wherein further layers can be arranged between the bottom plate and the cover plate. A connection between the bottom plate and the top plate may be configured to set a predefined distance between the bottom plate and the top plate. Various joining methods can be used in the step of joining, such as assembly, pressing and pressing, joining by welding, in particular by means of laser welding, ultrasonic welding, solvent bonding and simultaneously or alternatively gluing. In particular, it may be advantageous to stick the cover plate. Also, additional fasteners can be used in the step of joining. In the joining step, hybrid joining, ie a combination of at least two joining methods, can also be carried out. In hybrid joining, the advantages of the respective joining methods can be combined with each other.

Fig. 1

eine schematische Schnittdarstellung eines Pumpenelementes gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 2a

eine schematische Schnittdarstellung eines Pumpenelements gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 2b

eine schematische Schnittdarstellung eines Pumpenelements gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 3a

eine Dosierpumpe in einer schematischen dreidimensionalen Explosionsdarstellung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 3b

eine Dosierpumpe in einer schematischen dreidimensionalen Darstellung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 4

ein Pumpenelement in einer schematischen dreidimensionalen Darstellung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 5a und 5b

eine schematische Darstellung einer Implementierung der Funktionalität von zwei Rückschlagventilen in den Schichten eines Pumpenelements gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 6a bis 6d

eine schematische Darstellung eines Querschnitts des Pumpenelements gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;

Fig. 7

ein Ablaufdiagramm eines Verfahrens zum Herstellen eines Pumpenelements für eine Dosierpumpe gemäß einem Ausführungsbeispiel der vorliegenden Erfindung; und

Fig. 8a bis 8f

einen schematischen Fertigungsablauf eines Pumpenelements gemäß einem Ausführungsbeispiel der vorliegenden Erfindung.

The invention will now be described by way of example with reference to the accompanying drawings. Show it:

Fig. 1

a schematic sectional view of a pump element according to an embodiment of the present invention;

Fig. 2a

a schematic sectional view of a pump element according to an embodiment of the present invention;

Fig. 2b

a schematic sectional view of a pump element according to an embodiment of the present invention;

Fig. 3a

a metering pump in a schematic three-dimensional exploded view according to an embodiment of the present invention;

Fig. 3b

a metering pump in a schematic three-dimensional representation according to an embodiment of the present invention;

Fig. 4

a pump element in a schematic three-dimensional representation according to an embodiment of the present invention;

Fig. 5a and 5b

a schematic representation of an implementation of the functionality of two check valves in the layers of a pump element according to an embodiment of the present invention;

Fig. 6a to 6d

a schematic representation of a cross section of the pump element according to an embodiment of the present invention;

Fig. 7

a flow diagram of a method of manufacturing a pump element for a metering pump according to an embodiment of the present invention; and

Fig. 8a to 8f

a schematic production sequence of a pump element according to an embodiment of the present invention.

In the following description of preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various figures and similarly acting, wherein a repeated description of these elements is omitted.

Fig. 1 shows a schematic sectional view of a pump element 1 according to an embodiment of the present invention. The pump element 1 has a coupling bar 6, a pump membrane film 10, a bottom plate 12 and a cover plate 15. The bottom plate 12 is arranged plane-parallel to the cover plate 15 at a predefined distance. Between the bottom plate 12 and the cover plate 15 of the coupling bar 6 is arranged. Between the coupling bar 6 and the bottom plate 12, the pumping membrane film 10 is arranged. The pumping membrane film 10 is connected in a central portion 9 with the coupling bar 6. In a laterally adjoining the central portion 9 of the pumping membrane film 10 section 13, the pumping membrane membrane 10 is flexible. Lateral to the flexible portion 13 subsequent further section 14, the pumping membrane film 10 is connected to the bottom plate 12. The coupling bar 6 is designed to be moved by an actuator connected to it in a tolerance range perpendicular to the main extension plane of the bottom plate 12 between the bottom plate 12 and the top plate 15. Upon movement of the coupling bar 6 between the bottom plate 12 and the cover plate 15, a stroke of the coupling bar 6 is limited by a stop on both sides. As a result, a constant stroke of the coupling bar 6 and connected to the coupling bar 6 pumping membrane film 10 is achieved. The bottom plate 12 and the pumping membrane film 10 form a boundary of the pump chamber 11.

The pumping membrane sheet 10 can be divided into three sections. In a central portion 9, the pumping membrane film 10 is connected to the coupling bar 6. A flexible section 13 adjoins the central section 9 laterally. With the bottom plate 12, a further portion 14 is connected, which laterally connects to the flexible portion 13.

Fig. 2a shows a schematic sectional view of a pump element 1 according to an embodiment of the present invention. The pump element 1 corresponds to the in Fig. 1 shown pump element, with the difference that the coupling bar 6 is moved in the direction of the bottom plate 12 to the stop of the pumping membrane membrane 10 on the bottom plate 12. It can be seen here that the pump chamber 11 advantageously has no damaged volume.

Fig. 2b shows a schematic sectional view of a pump element 1 according to an embodiment of the present invention. The pump element corresponds to the in Fig. 1 and Fig. 2a shown pump element 1, wherein the coupling bar was moved to stop in the direction of the cover plate 15. The pump chamber 11 has a maximum volume. Fig. 2b illustrates that the suction of a fluid into the pump chamber 11 is actively controlled by an actuator of the coupling bar 6, is controlled.

Fig. 3a shows a metering pump in a schematic three-dimensional exploded view according to an embodiment of the present invention. The metering pump has a pump element 1 and an actuator unit 2. The pump element 1 is a disposable pump element. An actuator 3 of the actuator unit 2 is designed as a piezo bending transducer 3 with an actuator fork 4, the actuator fork 4 having four tines 5. The pump element 1 is now formed by a bottom plate 12, a pump membrane foil 10, a middle plate 7, a joining foil 18 and a cover plate 15. The bottom plate 12, the pumping membrane film 10, the middle plate 7, the joining film 18 and the cover plate 15 are arranged in layers, in particular in a tolerance range plane-parallel. On a main extension plane of the pump element 1, two axes AA and BB are shown. Along the axis AA, the pump element 1 is shown cut in the following figures. The axis BB corresponds to a direction axis in which the tines. 5 the fork 4 mounted on the piezoelectric transducing element 3 can be pushed into the pump element 1. The piezo bending transducer 3 is connected to an actuator base 3b. In other words shows Fig. 3a a metering pump with pump chip of a polymeric layer system.

The metering pump consists of a pump element 1, which can be used as a disposable component, and a reusable control / actuator unit 2. In this case, the pump element 1 is based on the principle of a membrane pump: by cyclically deflecting the membrane, liquid is displaced or sucked in, whereby (at least) two check valves are used to direct the flow. These functions in the pump element 1 are realized by means of three rigid, structured plates, that is to say the cover plate 15, the middle plate 7 and the bottom plate 12, as well as in each case flexible foils, that is to say the pumping membrane foil 10 and the joining foil 18.

One embodiment shows a pump element (for example as a disposable pump chip) and an actuator 2 whose actuator fork 4 consists of four prongs 5 which engage in the pump element 1 in order to actuate the pump membrane film 10. For the sake of clarity, the representation of the (vertical and lateral) fixing of the pump element 1 relative to the actuator base 3b has been dispensed with.

Fig. 3b shows a metering pump in a schematic three-dimensional representation according to an embodiment of the present invention. The metering pump shown essentially corresponds to that already in Fig. 3a shown metering pump. In this case, the pump element 1 is pushed onto the tines 5 of connected to the piezo bending transducer 3 fork 4 of the actuator 2, wherein the pump element 1 is shown cut along the axis AA. A coupling bar 6 is disposed between a bottom plate 12 and a top plate 15. In a plane to the coupling bar 6, a side wall of the middle plate 7 is arranged in the side wall portion 19. The pump element 1 is shown in the following figure Fig. 4 described in more detail.

In the following, it will now be explained how the power transmission from the actuator 2 to the pumping membrane film 10 takes place. For this shows Fig. 3b the pump element 1 and the actuator 2. Fig. 4 reveals their interaction inside the Pump element 1, by this along the in Fig. 3a drawn axis AA is shown cut open. For clarity, a representation of the control unit and the (vertical and lateral) fixation of the pump element 1 was omitted relative to the actuator base 3b. The core of the actuator 2 is a piezoelectric bending transducer 3, at the movable end of an actuator fork 4 is fixed so that it can be moved vertically to the pump element 1. The four prongs 5 of the actuator fork 4 are aligned parallel to one another and in extension of the bending transducer. Along this axis (BB, see Fig. 3a ), the pump element 1 can be pushed onto the fork, so that their tines 5 protrude into the pump element 1 and there with two tines 5 from above and two tines 5 from below a coupling bar 6 securely embrace this relative to the (remaining) pump element 1 in the vertical can be moved. To illustrate the interaction of actuator 2 and pump element 1, the pump element 1 is shown cut open. The enlargement of the pump element 1 in Fig. 4 shows the coupling bar 6, via which the movement of the actuator 3, and the actuator tines 5, is transmitted to the pumping membrane 10. Under the pumping membrane 10 is the pumping chamber 11. The fluidic access channels 20 to the pumping chamber 11 are illustrative, but do not exist in the illustrated embodiment.

Fig. 4 shows a pump element 1 in a schematic three-dimensional representation according to an embodiment of the present invention. Between a bottom plate 12 and a cover plate 15, a pumping membrane film 10, a center plate and a joining film 18 are arranged in layers. The bottom plate 12, the pumping membrane film 10, the middle plate, the joining film 18 and the cover plate 15 are arranged in a tolerance range plane-parallel to each other. The center plate is formed from a side wall (portion of the middle plate 7 in the side wall portion 19), a spring element 8 and the coupling bar 6. The joining film 18 has a recess outside or within the side wall. The side wall region 19 between the bottom plate 12 and the cover plate 15 is composed of the pump membrane film 10, the middle plate 7 and the joining film 18 together. The joining film has a recess, so that it is arranged only in the side wall region 19. The pumping membrane sheet 10 can be divided into four sections. In a central portion 9, the joining film 10 is connected to the coupling bar 6. In a laterally adjoining section 13 is the Pump membrane film 10 connected to neither the coupling bar 6 still with the bottom plate 12. The laterally arranged around the central portion 9 of the pumping membrane film 10 section 13 is designed to be movable. In a subsequent section 14, the pumping membrane film 10 is connected to the bottom plate. In a manufacturing step, the pumping membrane film can be connected, for example by means of laser welding to the bottom plate. Another portion of the pumping membrane film 10 is disposed in the side wall portion 19 and thus also determines the predetermined distance between the bottom plate 12 and the cover plate 15 with. The middle plate 7 is formed by the side wall, the coupling bar 6 and a spring element 8 arranged therebetween. In one embodiment, the middle plate 7 may be made in one piece, wherein the portion of the spring element 8 may be made thinner to provide a partially flexible portion of the middle plate 7 as a spring element 8. The coupling bar 6 is connected via the spring element 8 with the side wall. As a result, movements of the coupling beam in a tolerance range perpendicular to a main extension plane of the bottom plate 12 are made possible, deviating movements, especially movements in a direction of movement in a tolerance range parallel to the main extension plane of the bottom plate 12 suppressed.

The cover plate 15 has recesses 16 for tines of the actuator fork. Likewise, the bottom plate has recesses 17 for receiving prongs of the actuator fork. In Fig. 3b the tines of the actuator fork are arranged in the recesses 16, 17. Between the bottom plate 12 and the pumping membrane film 10, a pump chamber 11 is formed. The pump chamber 11 is formed so that through holes 20 in the bottom plate 12, a fluid can flow in and out. In this case, the pumping membrane film 10 is designed to generate by means of strokes a suction pressure or to squeeze out the fluid. The fluidic through-holes 20 as access channels to the pumping chamber 11 serve in the figure for illustration. In the presented embodiments, these do not exist, but rather the access channels are formed with integrated check valves according to the following figures shown embodiments.

The coupling bar 6 is fixed via a spring element 8 on the side wall of the center plate 7, so that vertical movements are possible and lateral are suppressed. In a manufacturing advantageous embodiment, the coupling bar 6 and the side wall of an element, wherein z. B. a vertically thinned area 8, the spring element 8 forms.

On the underside of the coupling beam 6, the central, movable region 9 of the pumping membrane film 10 is fastened, so that a deflection of the actuator 3 leads to a deflection of this pumping membrane film 10. The latter cyclically displaces the volume of liquid in the pumping chamber 11, which is located between a bottom of the pumping membrane film 10 and the top of the bottom plate 12. Radially outwardly from the central, movable region 9, the pumping membrane film 10 has a flexible portion 13 which is attached neither to the coupling bar 6 nor to the bottom plate 12 of the pump element 1. Thus, on the one hand, it can absorb the deformation of the pumping membrane film 10 due to the intended deflection (pump stroke), on the other hand, it should be so stiff that an unwanted deformation due to pumping pressures and back pressures is minimized. In a region 14 around the flexible portion 13 around the pumping membrane film 10 is fixed to the bottom plate 12 of the pump element 1. As a result, the lateral dimension of the pumping chamber 11 is defined. When joining the pumping membrane film 10 and bottom plate 12 by laser welding, this lateral dimension can be very easily adjusted to finely adjust the stroke volume of the metering pump or the pump element 1. This arrangement can thus lead to a concentric pumping chamber.

As in Fig. 3b see coupling beam 6 and bottom plate 12 in the pump chamber 11 plane-parallel surfaces. If the coupling bar 6 is deflected in the direction of the bottom plate 12, the entire pump membrane film 10 (or sections 9 and 13 of the pump membrane film 10) is ultimately pressed flat onto the bottom plate 12. The bottom plate 12 may be referred to as a bottom stop for the pumping membrane film 10. Thus, the pumping chamber 11 no Schadvolumen (or called dead volume), which has an advantageous effect on the compression ratio and the bladder tolerance. In particular, will In this case, the flexible region 13 of the pumping membrane film 10 is also pressed flat, even if a counter-pressure applied to the outlet of the metering pump or of the pump element 1 should have bulged it out beforehand. As a result, a low backpressure dependence of the delivery rate is to be expected.

The delivery volume is counted on the basis of the pumping strokes. For this purpose, a constant displacement is necessary. This is achieved by the fact that the coupling bar 6 is deflected to the bottom plate 12 when it is suctioned onto the cover plate 15 and when it is ejected. Advantageously, in the in Fig. 4 shown embodiment, this distance does not depend on the thickness of the cover plate 15 and the bottom plate 12, because they are kept only at the facing surfaces of the central plate 7 and the joining film 18 and the pumping membrane film 10 at a distance. Since it can be assumed that the thickness of the pumping membrane film 10 (at least) does not fluctuate locally and is therefore uniformly thick in the side wall region 19 and in the pump membrane region, ie the sections 9, 13 and 14), it likewise has no influence on the stroke or the lifting height. With the same argument, the influence of the thickness of the center plate 7 can be neglected. The stroke is thus defined by the thickness of the joining film 18, which cover plate 15 and bottom plate 12 holds at a distance, but in the region of the coupling bar 6 has a recess. The production-related thickness tolerance of the joining film 18 finally leads to a tolerance in the stroke. By means of, for example, optical measurement of the actual thickness of the joining film 18, this tolerance can be compensated by way of the already mentioned lateral adaptation of the pump diaphragm dimension, that is to say the lateral extent along the main extension plane of the base plate 12, in order to set an exact displacement volume or volume of the pump chamber 11 ,

Furthermore, in Fig. 4 also provided in the cover plate 15 recesses 16, which provide space for the tines, shown. Corresponding recesses 17 in the bottom plate are not shown for the sake of clarity. Inflow and outflow to the pumping chamber 11 could be realized, for example, by means of perforations 20 through the bottom plate 12, but so could the valves not within the existing levels (12, 10, 7, 18, 15) applied become. In an embodiment, not shown, a function monitoring can be integrated into the metering pump with pump element of polymeric layer system.

Fig. 5a and 5b 2 shows a schematic representation of an implementation of the functionality of two non-return valves in the layers of a pump element 1 according to one exemplary embodiment of the present invention. The illustration of the pump element 1 is with respect to Fig. 3a a section along the axis BB through a pump element 1. By means of the check valves, the flow of a fluid in the pumping chamber 11 can be directed. Shown is a cross section through the pump element 1 to illustrate the valve integration. Fig. 5a shows a suction phase. The inlet check valve 25 is opened. Liquid is sucked from the inlet 27 to the pumping chamber 11. In this case, the outlet valve is closed: its valve diaphragm 30 seals the path from the connecting channel 29 to the outlet valve through-hole 32. Fig. 5b shows an ejection phase. The overpressure in the pumping chamber 11 on the one hand closes the inlet valve 25, on the other hand it opens the outlet valve.

How the valve functions within the existing layers can be realized is Fig. 5a refer to. This shows the cross section along the insertion direction BB through the pump element 1. Inflow 21 and outflow 22 from the pumping chamber 11 are designed as channels (21, 22) in the bottom plate 12, which are covered by the pumping membrane film 10. The inflow channel 21 leads to the inlet valve chamber 23. There, the pump membrane foil 10 is structured (or perforated) in such a way that a valve head 25 suspended on spring arm 24 forms. The latter seals against a through hole 26 in the middle plate 7 or against a through hole 26 in the coupling bar 6, so that a check valve is formed.

From the through hole 26, the fluidic path can be guided directly through another through hole 27 by joining film 18 and cover plate 15 to the outside of the pump element 1. Alternatively, further functionalities could be created in the joining film plane 18, z. B. a filter for cleaning the fluid. Alternatively, the fluidic path can also be returned to the pumping membrane plane 10 and the inlet connection at the bottom of the Bottom plate 12 or laterally in the middle plate 7 are applied. Fig. 5a shows the inlet valve in open and Fig. 5b in the closed state.

From the pumping chamber 11, the drainage channel 22 leads via a through hole 28 in the pumping membrane film through a connecting channel 29 in the middle plate 7 to the outlet valve. This consists for. B. from a reference pressure valve: a flexible, closed membrane 30, which is formed by the pumping membrane 10 can deflect away from the center plate 7 in a valve chamber 31 and thereby release the fluidic path from the connecting channel 29 to the outlet valve through hole 32, so that the liquid can flow out of the pumping chamber 11. It makes sense to apply to the back of the closed membrane 30, the inlet pressure of the pump as a reference pressure (the chamber 31 has, for example, a channel to the pump inlet). Thus, the membrane 30 releases the through hole only when the pressure in the pumping chamber 11 rises above the inlet pressure due to active deflection of the pump membrane film 10, or of the central portion 9 of the pump membrane film 10. From the outlet valve through-hole 32, the fluidic path can be guided via a further through hole in the joining film 18 and the cover plate 15 to the outside. Corresponding to the remark in the description of the inlet valve, attention should be drawn here to the simple possibility of integrating further fluidic functions, in particular to that of a (threshold) pressure sensor. Fig. 5a shows the exhaust valve in closed and Fig. 5b in the open state. By applying the valves in the axis perpendicular to the coupling beam axis (AA), the length of the channels between valves and pump chamber 11 remains small, so that fluidic resistances, capacitances and inductances remain minimal.

For the embodiments shown, other alternatives are conceivable. Instead of a piezo bending transducer other actuation mechanisms are conceivable such. B. reluctance, electric motors, electroactive polymers, shape memory actuators and linear magnets. The actuator can also be connected to the pumping membrane differently than via the fork described above, for example by locking a mandrel in an opening, welding or gluing. In addition, the fork can be divided into 2-4 subunits, each with an actuator, in particular so that the tines left and right of the axis BB can be controlled separately. In the control unit can a Power supply (eg battery, rechargeable battery), wireless or wireless communication interface (eg USB, WLAN), display, buttons (fields), alarm vibrators and / or loudspeakers. An alternative embodiment based on other check valves is shown in FIG Fig. 6a to 6d shown.

Fig. 6a to 6d show a schematic representation of a cross section of the pump element 1 according to an embodiment of the present invention. Clearly, an implementation of the functionality of two check valves in the layers of the pump element 1 is shown. The pump element 1 is constructed of a base plate 12, a pumping membrane film 10, a middle plate 7, a joining film 18 and a cover plate 15 in a layered manner. The center plate 7 has a coupling bar 6, which is designed to be moved by an actuator and thus to provide a pump stroke. Fig. 6a shows a resting state, both check valves 35, 36 are closed. Fig. 6b shows the pumping element in the state of liquid suction, the coupling bar 6 is driven up to the stop on the cover plate 15 "up", the pumping membrane 10 is deflected maximum and the pumping chamber 11 has the maximum volume. Due to the resulting negative pressure in the pumping chamber 11, the inlet valve 35 is opened. A fluid may flow through the opened inlet valve 35 until the pressure in the pressure chamber is equalized. It turns then the in Fig. 6c shown state in which the suction is completed and the check valves 35, 36 are both closed. In an intermediate step, not shown, the coupling bar 6 can be moved in the direction of the bottom plate. It turns the in Fig. 6d shown state. By the movement of the coupling bar 6 in the pumping chamber 11, the pressure increases, that is, the pumping diaphragm displaces liquid, and the outlet valve 36 is opened and the fluid flows out until the pressure is balanced again and the in Fig. 6a restores the displayed state. In the embodiment shown, the bottom plate 12, the middle plate 7 and the top plate 15 are rigid plates. The pump membrane film 10 and the joining film 18 are designed as elastic membrane. In other words, they show Fig. 6a to 6d a pumping cycle of an alternative embodiment. The valve function is here via through holes in the valve diaphragm, simultaneously the pumping membrane sheet 10 is ensured instead of perforations in the rigid middle plate 7.

Fig. 7 FIG. 12 shows a flow chart of a method 700 for manufacturing a pump element for a metering pump according to an embodiment of the present invention. The pump element may be an in Fig. 1 to Fig. 6 act shown pump element. The method 700 includes a provisioning step 710, an arranging step 720, and a joining step 730. As shown in Fig. 7 The steps are executed sequentially one after the other. In a further embodiment, the steps are subdivided and repeatedly executed in different order. In the providing step 710, at least a bottom plate, a top plate, a coupling bar, and a pumping membrane foil are provided. In the step of arranging 720, the coupling bar and the pumping membrane film are arranged between the bottom plate and the top plate, wherein the bottom plate is arranged at a predefined distance to the top plate. In the step of joining 730 the bottom plate, the pumping membrane foil, the coupling bar and the top plate, the described elements are joined so as to provide a pump element. In the step of joining 730, the pumping membrane film can be joined to a structured base plate, the pumping membrane film can be joined to the coupling plate, then a joining film can be joined to the middle plate, in particular in the sidewall region, and the pump element can be joined to the joining film by joining the cover plate to get finished. Between the steps of arranging 720 and joining 730, a structuring step may be added, in which the already arranged layer is further patterned prior to joining, for example to provide the functionality of a check valve in the pumping element.

In the method 700 for manufacturing a pump element for a metering pump, in one embodiment, not shown, a layer may be provided, then a layer in contact with the provided layer may be arranged therefor to join the two layers before the subsequent layer is placed , Before and at the same time or alternatively after the sub-step of the joining, a step of the Structuring be inserted. In Fig. 8a to 8f an embodiment of a method 700 for producing a pump element for a metering pump is shown.

The following material examples can be used depending on the embodiment. As solid polymer layers, the bottom plate, the middle plate and the cover plate may be made of thermoplastics (eg PC, PP, PE, PMMA, COP, COC). The pump membrane film and the joining film can be produced as an elastic membrane, for example, from an elastomer, a thermoplastic elastomer, or a thermoplastic. The thickness of the lid and base plate 0.6 mm to 10 mm, the thickness of the flexible valve film or pumping membrane film 30 microns to 300 microns and the depth of a valve chamber 5 microns to 150 microns. The dimensions for the diameter of the valve chamber 200 microns to 2000 microns, the perforation of the valve film 10 microns to 1000 microns, and the welding of the coupling beam to the pumping membrane 0.1 mm to 10 mm and the welding of the pumping membrane to the bottom plate 1 mm to 30 mm.
As a manufacturing method, for example, the solid layers by injection molding, injection compression, hot stamping, laser cutting, milling, punching or combinations thereof can be produced. All layers can be joined - in particular the pump membrane foil on the bottom plate and center plate by means of laser welding. Of course, other joining methods can be used such. B. ultrasonic welding or solvent bonding. The lid can also be glued on. Fig. 8a to 8f sketchy shows a possible production process.

Fig. 8a to 8f show a schematic production sequence of a pump element according to an embodiment of the present invention. The pump element may be an in Fig. 1 to Fig. 6 described pump element 1 act. In particular, it may be an embodiment of an in Fig. 6a to 6d shown embodiment of a pump element act. The production process can be an in Fig. 7 already illustrated method 700 for producing a pump element for a metering pump. In Fig. 8a a pumping membrane film 10 is arranged on a structured bottom plate 12. The pumping membrane film 10 and the Base plate 12 can be welded together in the joining step. Fig. 8b shows an intermediate step of structuring, are structured in the valve regions of the pumping membrane sheet 10. Fig. 8c shows the step of arranging the middle plate 7 on the structured pumping membrane sheet 10. In the step of joining, the pumping membrane sheet 10 and the center plate 7 arranged thereon can be welded. Fig. 8d shows a side view of the already in Fig. 8c shown layers of the pump element. Here, the partial areas of the side wall, the spring element 8 and the coupling bar 6 can be seen. In one embodiment, the side wall 7, the spring element 8 and the coupling bar 6 can be made in one piece. Fig. 8e shows the lid, that is, after arranging the joining film 18, at least in the sidewall area, the cover plate 15 is arranged and the joining film and the cover plate are welded and / or glued. Fig. 8f shows a page representation of the in Fig. 8e already completely arranged and assembled pump element.

In other words shows Fig. 8a to 8f a brief overview of an embodiment for the preparation of the pump element. In steps 1 and 2, the laser power is injected through the bottom - at steps 3 and 4 through the top.

The embodiments described and shown in the figures are chosen only by way of example. Different embodiments may be combined together or in relation to individual features. Also, an embodiment can be supplemented by features of another embodiment.

Furthermore, method steps according to the invention can be repeated as well as carried out in a sequence other than that described.

If an exemplary embodiment comprises a "and / or" link between a first feature and a second feature, then this is to be read so that the embodiment according to one embodiment, both the first feature and the second feature and according to another embodiment either only first feature or only the second feature.

Claims (10)

Pump element (1) for a metering pump, the pump element (1) having the following features: a lid plate (15); a bottom plate (12), wherein the bottom plate (12) is arranged at a predefined distance to the cover plate (15); a coupling bar (6) disposed between the lid plate (15) and the bottom plate (12), the coupling bar (6) being coupleable to an actuator unit (2) and movable between the bottom plate (12) and the lid plate (15); a pump membrane film (10) arranged between the cover plate (15) and the bottom plate (12), wherein the pump membrane film (10) in a central portion with the coupling bar (6) is connected and by means of the coupling bar (6) with the actuator unit (2 ), wherein the pump membrane film (10) has a laterally adjacent to the central portion (9) flexible portion (13) and a laterally adjoining connected to the bottom plate (12) further portion (14) and the pumping membrane membrane (10) is formed, between the pumping membrane membrane (10) and the bottom plate (12) to provide a pumping chamber (11). Pump element (1) according to claim 1, wherein the coupling bar (6) with a spring element (8) and / or a side wall forms a middle plate (7) which is arranged between the cover plate (15) and the bottom plate (12) the spring element (8) is formed, the movement of the center plate (7) on a movement within a tolerance range perpendicular to the main extension plane of the bottom plate (12) and / or cover plate (15) restrict. Pump element (1) according to claim 2, in which the coupling bar (6), the spring element (8) and the side wall are integrally formed as a central plate, in particular wherein a thinned portion of the middle plate (7) separates the spring element (8) between the coupling bar (8). 6) and the side wall forms. Pump element (1) according to one of the preceding claims, comprising at least one joining film (18) arranged between the cover plate (15) and the bottom plate (12), wherein the joining film (18) in the region of the coupling bar (6) has a recess at least in size of the coupling bar (6). Pump element (1) according to one of the preceding claims, wherein the cover plate (15) and / or the middle plate (7) and / or the bottom plate (12) is made of a thermoplastic polymer. Pump element (1) according to one of the preceding claims, wherein the joining film (18) and / or the pumping membrane membrane (10) is made of an elastomer, a thermoplastic elastomer and / or a thermoplastic as an elastic membrane. Pump element (1) according to one of the preceding claims, with at least one check valve, in particular at least two check valves for directing a flow of a fluid in the pumping chamber (11). Metering pump, wherein the metering pump has the following features: Pump element (1) according to one of claims 1 to 7; and Actuator unit (2) for a metering pump, which is designed to move the coupling bar (6) in a tolerance range perpendicular to the bottom plate (12) and / or cover plate (15), wherein the actuator unit (2) by means of at least one actuator fork (4) and / or at least one mandrel engaging in an opening and / or welding and / or gluing to the coupling bar (6) of the pump element (1). Dosing pump according to claim 8, wherein the actuator unit (2) is designed as at least one piezo bending transducer and / or at least one reluctance actuator and / or at least one electroactive polymer and / or at least one shape memory actuator and / or at least one linear magnet. Method (700) for producing a pump element (1) for a metering pump according to one of the preceding claims, the method (700) comprising the following steps: Providing (710) at least one bottom plate (12), a top plate (15), a coupling bar (6) and a pumping membrane film (10); Arranging (720) the coupling beam (6) and the pumping membrane film (10) between the bottom plate (12) and the cover plate (15), the bottom plate (12) being arranged at a predefined distance from the cover plate (15); and Joining (730) the bottom plate (12), the pumping membrane foil (10), the coupling bar (6) and the top plate (15) to produce a pump element (1) according to any one of claims 1 to 7.

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