EP0884475B1 - Multiple chamber pump - Google Patents

Description

The invention relates to a multi-chamber pump for metered Conveying small amounts of fluid according to the in the preamble of Claim 1 specified genus.

A pump of this type, in particular the delivery of Blood serum in the microliter range is from US-A-5 593 290 known. The chambers are in one Pump body designed as hemispherical depressions and are covered by a membrane on the top. The hemispherical chambers stand through overflow channels with each other and through further channels with the inlet or outlet in connection. The channels open inside the curved Chamber walls, and in the idle state all chambers stand together and in connection with inlet and outlet. By feeding overpressure can cause the membrane to the cavity walls be pressed, causing the volume of the chambers to open Bring to zero and the connections are blocked. At initiation the pumping process from the rest position of the membrane the volume of the chambers must first be brought to zero, by subjecting the membrane to excess pressure adapt to the internal shape of the chambers. Only then can you create a vacuum the pumping process by enlarging of the chamber volume can be initiated.

In a diaphragm pump according to US-A-4 265 601, a pump medium for the membrane causing the pumping process in one Heating chamber pulsed by an electrical heating resistor heated, causing the membrane to convey liquid pushes out of the pumping chamber during the suction process the volume of the pumping chamber is reduced. The pumping chamber and the diaphragm valves between the inlet and outlet are housed in a massive split block, the is provided with appropriate connecting holes. The Pumping process is effected here by a single diaphragm pump, which is operated depending on the temperature via the heating device becomes.

In a micropump described in US-A-5,096,388 the pump membrane is magnetic or electrical Field actuated, with inlet and outlet channels in a semiconductor material are provided and with a semiconductor membrane a pattern of channels under selective control of activation agents interacts to form a wavy on the membrane To induce movement that has a pumping action between Inlet and outlet causes. Instead, a piezoelectric can also be used or electrostrictive mechanism are used to bring about the membrane movement.

The connections are in a micropump according to EP-A-0 134 614 between two neighboring chambers, each via one circular membrane covered, the piezoelectrically raised can be and thereby causes suction, while the Pressurization occurs when the membrane is at rest returns in which the connecting lines again are cordoned off. An operational change for the Pumping the necessary volume is not possible, so that the delivery rate is only set by changing the switching frequency can be.

The invention has for its object a generic To create multi-chamber pump, which from the rest position responds instantaneously, a sensitive and accurate Setting the delivery rate guaranteed and with simple Construction works reliably.

The task is solved by the in the labeling part of claim 1 specified features.

The layer structure consisting of the individual silicon wafers is easy to manufacture with high precision. At rest, i.e. without pressure supply, the chamber volume equals zero, and the chambers are against and against each other Inlet and outlet blocked. The pumping process can be done from this Rest position immediately with the required precision be initiated.

Advantageous refinements and developments of the invention result from the subclaims.

In feed pumps allow actuators provided according to the invention within large areas a practically continuous adjustment or Changing the chamber volume, reducing the delivery rate can be adjusted accordingly.

By using the narrow overflow channels, the large ones Volume of connecting channels avoided and venting the Feed pump before commissioning can in most cases omitted.

At least when using a feed pump chamber as a valve partially blocking a media flow the valve can be opened practically anywhere or be closed by the valve inlet or outlet correspondingly strong due to the elastically deformable element or is covered to the appropriate extent, creating the desired Media (through) flow can be adjusted precisely. Of course is still (additionally) one only switching operating mode of the valve possible.

When the feed pump is operating, the medium to be delivered is the based on the conveying direction of the first chamber and overflow ducts connecting this via adjacent chambers up to the last in relation to the conveying direction Chamber forwarded in connection with the media outlet stands.

The transfer of the medium to be conveyed from chamber to chamber takes place by changing the chamber volume, or thereby that the fluidic resistance in the conveying direction is reduced and is enlarged in the opposite direction.

According to a preferred embodiment of the invention, the Delivery direction of the feed pump can be reversed as desired, whereby the functions of the media inlet and the media outlet change accordingly.

This reversal of the conveying direction is preferably carried out exclusively by changing the order in which the Volume adjusters change the volume of the chambers.

The volume adjusters and especially the order the volume changes of the chambers achieved with these are preferably from any suitable rule and / or Control device coordinates, preferably at least Periodic operation is provided for individual periods is.

Especially when the feed pump is in the form of a micro feed pump this should at least be realized partially made of silicon, which is made with the processes known from semiconductor technology are processed can.

The same naturally applies accordingly to the application a feed pump chamber as a valve.

The feed pump according to the invention is based on the Drawings explained in more detail.

Fig. 1

eine stark vereinfachte schematische Darstellung der erfindungsgemäßen Förderpumpe;

Fig. 2

eine Ausführungsform der erfindungsgemäßen Förderpumpe in Form einer Mikroförderpumpe.

The drawings show:

Fig. 1

a highly simplified schematic representation of the feed pump according to the invention;

Fig. 2

an embodiment of the feed pump according to the invention in the form of a micro feed pump.

In Fig. 1 is a highly simplified example of the structure a feed pump according to the invention. The illustrated Feed pump has three chambers 3, 4, 5 which are related the conveying direction R arranged essentially one behind the other are. The volume of the chambers 3, 4, 5 can be adjusted using volume adjustment devices 15,16,17 changed or set become what is shown schematically by the dashed lines in Fig. 1 is indicated.

The first chamber 3 with respect to the conveying direction R has one Media inlet 1 through which the medium to be conveyed is the first Chamber 3 is supplied. There are two adjacent chambers via also schematically shown overflow channels 6.7 connectable.

The medium to be pumped is from the first chamber 3 to last chamber 5 forwarded via the overflow channels 6,7 leaving the chamber 5 through a media outlet 2. The Forwarding of the medium to be conveyed from one chamber to next is achieved in that the volume of at least one of two adjacent chambers 3, 4, 5 using the volume adjustment device 15,16,17 is changed.

The volume adjustment devices 15, 16, 17 are electromagnetic Lifting elements and / or positive and / or negative pressure generating devices educated.

The change in chamber volume can occur in the chambers generate a positive or negative pressure, with the help of which to promoting medium ejected from the chamber or into the corresponding Chamber can be sucked.

Depending on whether it is as uniform or impulsive as possible Conveying the medium is desired, the volume changes of the chambers 3, 4, 5 in the most varied of orders and combinations, preferably one not illustrated regulation and / or control device the operation coordinates the volume adjustment device.

Furthermore, the delivery direction R is when the feed pump is operating preferably reversible as desired, this reversal of the conveying direction R and the associated change in the functions of the Media inlet 1 and the media outlet 2 thereby achieved will change the order in which the volumes the chambers 3, 4, 5 through the volume adjustment devices 15, 16, 17 can be changed.

For the simplest case, in which only two chambers 3, 4 are provided volume changes, for example in such a way that at the beginning both chamber volumes, for example are reduced to 0, after which the volume of the chamber 3 is enlarged until the desired amount of medium to be conveyed is located in chamber 3, after which at simultaneous increase in the volume of the chamber 4 that Volume of the chamber 3 is reduced again, so that the medium reaches the chamber 4 via the overflow channel 6, from the it by reducing the volume of the chamber 4 again is expelled again.

As already mentioned, and especially in the event that several Ejections can be arranged one behind the other the medium from a chamber are supported in that the volume of the adjacent chamber is increased by one To achieve suction.

In the embodiment of the feed pump shown in FIG. 2 the feed pump has a layered structure. How this from the exploded view in FIG. 2 is recognizable, the feed pump exists with regard to the representation from the top down from a silicon plate 21, (a second cover plate) one Media inlet 1 and a media outlet 2, a silicon wafer 14, (a second plate) to form the overflow channels 6,7 two Window 19.20 and regarding the media inlet and outlet has two other smaller openings, one elastic deformable membrane 13 in the form of a polymer film, a Silicon plate 18, (a first plate) which has openings 10, 11, 12 in which the membrane 13 may extend to between the Silicon plate 14 and the membrane 13, the chambers 3,4,5 to form, and an element 22, (a first cover plate) the actuators 15, 16, 17, each the volume of the chambers determine.

In the illustrated embodiment, the volume adjustment devices in the form of positive and / or negative pressure generating devices 15,16,17 formed in the recesses 10,11,12 can create a negative pressure, whereby the corresponding sections of the membrane 13 in these recesses 10,11,12 extend and thus between the silicon wafer 14 and the membrane 13 form the chambers 3,4,5.

The overflow channels 6,7 are through the arranged in the silicon wafer 14 Window 19.20 formed, of which each two adjacent breakthroughs 10,11,12 and thus overlaps two adjacent chambers 3, 4, 5.

Although this is not shown, the medium to be funded can supplied or discharged via flow diodes and / or flow restrictors to prevent undesired backflow of the medium prevent, in particular flow diodes preferably only be used in the event that any reversibility the conveying direction R is not desired or required.

LIST OF REFERENCE NUMBERS

1

inlet port

2

outlet

3

chamber

4

chamber

5

chamber

6

overflow

7

overflow

10

breakthrough

11

breakthrough

12

breakthrough

13

membrane

14

second tile

15

locking device

16

locking device

17

locking device

18

first tile

19

window

20

window

21

second cover plate

22

first cover tile

R

conveying direction

Claims (6)

1. A multi-chamber pump for the metered delivery of small amounts of fluid, in which

   the chambers (3, 4, 5) which are connected in succession in the delivery direction (R) by flow transfer passages (6, 7) are partially delimited by a flexible diaphragm (13), and

   to alter the volume of the chambers (3, 4, 5) the diaphragm (13) is deformed by adjusting devices (15, 16, 17) by means of an increased pressure and/or a reduced pressure, in order periodically to fill the chambers (3, 4, 5) and empty them towards the following chamber by way of the flow transfer passages (6, 7);

      characterised by the following features:

   arranged in a first plate portion (18) are through openings (10, 11, 12) which are covered on the one hand by the diaphragm (13);

   the chambers (3, 4, 5) are formed in the through openings (10, 11, 12) of the first plate portion (18) when the diaphragm (13) is extended thereinto by the adjusting devices (15, 16, 17);

   provided in a second plate portion (14) which lies on the diaphragm (13) are windows (19, 20) which respectively overlap two chambers (3, 4, 5) in the first plate portion (18) and form the flow transfer passages (6, 7);

   placed under the first plate portion (18) is a first cover plate portion (22) which in the region of the through openings (10, 11, 12) disposed thereabove is connected to the adjusting devices (15, 16, 17);

   placed over the second plate portion (14) is a second cover plate portion (21); and

   over the first chamber (3) and the last chamber (5) the second plate portion (14) has inlet openings (1) and outlet openings (2) respectively which align with openings in the second cover plate portion (21).
2. A multi-chamber pump according to claim 1 characterised in that the plate portions (14, 18, 21, 22) are silicon plate portions.
3. A multi-chamber pump according to claim 1 characterised in that the media inlet (1) and/or the media outlet (2) is connected to the chambers (3 and 5 respectively) by way of flow diodes and/or flow throttles.
4. A multi-chamber pump according to one of the preceding claims characterised in that the media inlet (1) and the media outlet (2) have the same flow resistance.
5. A multi-chamber pump according to claim 4 characterised in that the media inlet (1) and the media outlet (2) are of the same cross-section.
6. A multi-chamber pump according to claim 1 characterised in that the volume of the chambers (3, 4, 5) is reduced substantially to zero when the diaphragm (13) is in its rest position.

Images