DE102016218659A1 - check valve - Google Patents

Abstract

The invention relates to a check valve (1, 1a). In order to provide a check valve with integrated flow sensor which can be produced simply and inexpensively, it is provided according to the invention that the check valve has the following: a base body (2) with at least one through-opening (4, 5), an electrically conductive membrane (3) along one X-direction in succession a first, fixed to the base body portion (3.1) having a first electrical contact (7), and a second, movable portion (3.2), wherein the base body (2) at least one extending in the X direction electrode ( 6, 6a) which is connected to a second electrical contact (8), and wherein in a closed position, the membrane (3) covers the at least one passage opening (4, 5) and the second section (3.2) adjacent to the at least one electrode (6, 6a) is arranged.

Description

The invention relates to a check valve.

In the prior art, various methods are known for measuring the flow of a fluid, ie a gas or a liquid, through a conduit or the like. As a flow in this context, the volume flow (volume per unit time) or the mass flow (mass per unit time) are considered. Measuring devices used for this purpose are sometimes referred to as flow meters or flow meters. Apart from mechanical solutions, such as the oval gear meter or the turbine wheel meter, various other measuring methods (optical, electromagnetic, ultrasonic-based and others) enable the detection of the current flow of a fluid. The majority of available methods provide high quality results, but are usually very costly to implement. This means, in particular, a relevant limitation for the automotive industry, where the cost plays a major role.

There have also been proposed solutions in which a flow sensor is integrated into a check valve. Such a check valve, which prevents the flow of a fluid in one direction and allows in the other direction, can be used in a variety of areas. If a measurement of the flow is desired, the integration of a corresponding sensor in the check valve is advantageous because this can usually be saved in space. However, here is a structurally simple as possible, cost-effective solution desirable.

In the field of motor vehicle construction, such a check valve could be used with a flow sensor, for example. Within a system for brake booster, which would make it possible not only to control the direction of flow of air from a brake booster to a vacuum source (eg., A vacuum pump), but also to measure the flow.

The GB 954.048 A discloses a check valve having a valve body and an annular diaphragm inserted therein, which abuts in a closed position on a central insert element of the valve body. Here, the membrane closes a circumferentially formed around the insert element between this and the outer wall of the valve body opening. In an open position, the membrane is lifted off the insert element and thus releases the opening. The membrane cooperates with a slidably guided by the outer wall rod, which in turn can act on an external potentiometer, through the resistance of the flow rate through the check valve can be determined.

The US 3,587,326 A discloses a device for measuring acceleration. Here, a sample mass is connected to an elastic membrane which closes a fluid-filled chamber. The chamber communicates via a check valve with a tube in which a drop of liquid metal is arranged. On the opposite side of the drop, the tube passes into a closed chamber and is filled with a pressurized gas. Opposite conversion sections of the tube are covered with a conductor element or a resistance element, which each extend in the axial direction. The elements mentioned form together with the metal droplets parts of a circuit. The resistance of the same can determine the position of the metal drop, which in turn depends on the position of the sample mass under the influence of an acceleration.

The US 8,800,473 B1 describes a flow sensor with a base part, which can be used, for example. In a pipe system, and a pivotally mounted thereon, spring-loaded baffle element, which can at least partially fill a pipe cross-section in a rest position. Arranged on the baffle element is an arcuate display section, which moves from the rest position into a display chamber of the base part during the deflection of the baffle element. The display chamber may, for example, be designed to be transparent, so that the position of the damming element, which corresponds to a flow rate, can be read visually. Alternatively or additionally, the position can be registered electrically, for example via a Hall sensor on the display chamber and a magnetic element on the display section.

The US 3,914,994 A discloses a flow sensor having a tubular body and a valve flap pivotally mounted therein which contacts a switch in a fully closed position and contacts a resistance wire in different positions in a partially or fully opened position. The resistance wire acts in the manner of a potentiometer, so that the resistance of the opening state and thus the flow rate can be determined.

The US 4,926,903 A shows an arrangement with a butterfly valve, which is pivotable about an axis which is drivable via an actuator. The axle is coupled via a gear reducer to a potentiometer, with the help of the swing angle is measured. Furthermore, the torque is measured in the axis. About a z. B. empirically determined relationship can be determined from the measured values for swivel angle and torque, the flow rate along the butterfly valve.

The US 4,213,021 A discloses a check valve with a valve body in which a spring-loaded closing element is arranged, with which the valve body can be closed. The closing element has a magnet and in the wall of the valve body, a reed switch is arranged, which is closed depending on the position of the closing element by the magnet or opens. This can be used to close the condition of the reed switch on the flow rate within the valve. To avoid hysteresis causing effects to open or close at significantly different flow rates, the closure member has a special geometric configuration with a nose portion. This results in that the flow rate remains approximately the same over a certain displacement path of the closing element.

The US 2008/0053537 A1 discloses a check valve having a valve body having an opening and a flap which is pivotally mounted on the valve body and can release or close the opening. On the valve body first and second conductor elements are arranged, which are spaced from each other. A third conductor element is disposed on the flap and dimensioned to close the gap between the first and second conductor elements. Depending on the arrangement, it is possible to determine the closed or closed state of the flap by closing a circuit.

In view of the state of the art, the provision of a check valve which can be produced simply and inexpensively and which permits the most accurate flow measurement still offers room for improvement.

The invention has for its object to provide a simple and inexpensive to produce check valve with integrated flow sensor.

According to the invention the object is achieved by a check valve having the features of claim 1, wherein the dependent claims relate to advantageous embodiments of the invention.

It should be noted that the features listed in the following description as well as measures in any technically meaningful way can be combined with each other and show other embodiments of the invention. The description additionally characterizes and specifies the invention, in particular in connection with the figures.

The invention provides a check valve. As a check valve in this case each type of valve is considered, which allows in dependence on a pressure difference on the two sides of the valve, the passage of a fluid, ie a gas or a liquid in one direction and prevents in the opposite direction. In particular, the check valve according to the invention can be used to regulate the flow of a gas, for example air. The check valve has a base body with at least one passage opening. The base body may also be referred to as a valve body and corresponds to the stationary part of the check valve, which is installed, for example, on or in a fluid line. For this purpose, it may comprise connecting means such as threads or holes for receiving screws. The at least one passage opening is used in the operating state to allow passage of the fluid through the check valve. With regard to the geometry of the at least one passage opening, there are no restrictions within the scope of the invention. For example. For example, the passage opening may be elongated or short in the intended passage direction of the fluid.

Furthermore, the check valve has an electrically conductive membrane, which has along a X-direction successively a first, fixed to the base body portion having a first electrical contact, and a second, movable portion. The term "membrane" in this case implies that it is a flexible, at least partially planar body formed. The term "X-direction" in this context only serves as a reference and does not imply orientation in relation to the installation position within a fluid conduit, to the passage direction of the fluid or the like. Thus, along this X-direction one can distinguish two sections, the first of which is fixed to the base body, while the second is movable relative to the base body (and the first section). The mobility is of course accompanied by a deformation of the flexible membrane. In this case, the second section can in particular be lifted off the base body, that is, move perpendicularly to its surface. The first section may be fastened to the base body, for example, by material bonding by gluing or ultrasonic welding, but if necessary also by force-locking and / or positive locking, for example by clamping.

The membrane is electrically conductive, which includes both the possibility that it is made entirely of an electrically conductive material exists (for example, a polymer matrix, in which electrically conductive particles are incorporated) or even that it is only partially electrically conductive, z. B. has a conductive coating. In this case, a first electrical contact is arranged on the first section, which, for example, allows the connection to a current or voltage source. The electrical contact can be made very simple, for example. As a metallic pin to which a cable can be soldered, or as a connector. It is also possible that immediately adjoins the electrical contact an electrically connected to the check valve electrical line. Such a line can, for. B. may also be formed as a conductor on a circuit board, which forms at least a part of the base body. On such a circuit board further interconnects may be applied, whereby a layered arrangement of a plurality of mutually insulated interconnects is possible. It is understood that the first electrical contact with the membrane or with its electrically conductive part is conductively connected.

Furthermore, the base body has at least one extending in the X direction electrode, which is connected to a second electrical contact. The at least one electrode extends in the X direction, meaning that it has a non-negligible extent in the X direction. It is also possible that several electrodes are provided in succession in the X direction. Likewise, a plurality of electrodes may be provided, which are spaced apart transversely to the X direction. At least one electrode can be formed flat on or below the surface of the base body. In this case, the electrode or each electrode is connected to the second electrical contact, which includes the possibility that the second electrical contact is formed directly on an electrode. Apart from the connection to the second electrical contact, the at least one electrode can be electrically insulated toward the outside (for example, by a dielectric) or else it can be at least partially electrically contactable. The at least one electrode is electrically conductive in itself, so that at least within the same charges or currents can flow. The above statements regarding the design of the first contact also apply to the second contact. Of course, the second electrical contact is electrically connected to the at least one electrode and allows connection to a source of current or voltage. It can be arranged in particular on the base body.

In this case, in a closed position, the membrane covers the at least one passage opening and the second section is arranged adjacent to the at least one electrode. Of course, this is the closed position of the check valve, in which this prevents passage of a fluid against the intended direction. In this case, the membrane acts as a closing element which covers the at least one passage opening. It can also be said that the membrane completely closes the passage opening or closes completely covering it. In order to be able to act as a movable closing element, the membrane at least partially covers the passage opening with the second, that is to say movable section. Preferably, the passage opening is predominantly, ideally completely covered by the second section. Furthermore, in the closed position, the second section is arranged adjacent to the at least one electrode, which includes the possibility that the second section contacts the at least one electrode. Due to the proximity of the electrically conductive membrane to the at least one electrode, the closed position can be detected by measuring at least one electrical variable. For example. For example, the at least one electrode may be insulated by a dielectric, wherein the electrically conductive membrane acts as a counterelectrode. Depending on the position of the second section relative to the at least one electrode, the capacitance of the arrangement changes, wherein the closed position, a certain, often characteristic, capacity can be assigned. In this case, therefore, the first and the second electrical contact would be connected to those of a voltage source, resulting in a capacitance-dependent charging of the arrangement.

In a pass-through position, however, the second section is at least partially lifted from the base body, which means, on the one hand, that the at least one through-opening is at least partially released, and, on the other hand, that the second section moves away from at least one electrode. In any case, this leads to a change in the electrical properties, for example to a change in the capacitance, wherein there is a relationship between a changing electrical measured variable and the released area of the through opening. In the check valve according to the invention, it is thus possible to determine the opening state of the valve or the flow through the same via a measurement of an electrical variable. Depending on the geometric and material configuration of the various elements of the relationship between the measured variable and the flow can be complicated (especially non-linear), but it can be z. B. can be determined in tests by calibration.

The invention thus provides a check valve which can be used simultaneously as a flow sensor. The check valve can be relatively simple and thus be constructed inexpensively. Also, a very space-saving design is possible. It should also be noted that normally the second section of the diaphragm is the only moving part of the valve, which results in virtually no wear and also hardly blocks the valve. Normally, the only movement is lifting the second section off the base body, ie there is no friction between moving parts against each other.

During the transition from the closed position into the passage position, the part of the second section which is farthest from the first section preferably first dissolves, whereby further parts of the second section successively dissolve with increasing pressure difference, and the at least one through-opening gradually becomes smaller release. This in turn causes the second section to gradually move away from the at least one electrode, which is accompanied by a successive change of the measured variable.

Preferably, at least one resistance element extending in the X-direction is arranged on the base body as the electrode, wherein in the closed position the second portion bears against the resistance element. Of course, the term "resistive element" implies an electrical resistance, but is not to be construed as limiting the total resistance or resistivity. Thus, the resistance or the specific resistance of the resistance element may be less than that of the electrically conductive membrane. The resistance element may, for example, be formed in layer form as a carbon, metal or metal oxide sheet resistance.

In this case, the second section is located in the closed position on the resistance element. As a result, an electrical connection is made, which is why the membrane must be electrically conductive at least on the side facing the resistance element. In the closed position, therefore, an electrical connection results overall from the first electrical contact via the electrically conductive diaphragm and the resistance element to the second electrical contact. Thus, an electric current can flow and from the ratio of voltage and current, a total resistance can be determined, which is characteristic of the closed position.

In the passage position of the second portion is at least partially lifted from the base body, which means that the at least one through hole is at least partially released, on the other hand, but that the second portion may only partly or not at the resistance element. As a result, the total resistance that can be measured between the first and second electrical contacts changes, with a relationship between the measured resistance and the released area of the through opening. In this embodiment, it is thus possible to determine the opening state of the valve or the flow through the same via a resistance measurement. The relationship between the resistance and the flow can be complicated (especially non-linear), but it can be z. B. can be determined in tests by calibration.

During the transition from the closed position into the passage position, the part of the second section which is farthest from the first section preferably first dissolves, whereby further parts of the second section successively dissolve with increasing pressure difference, and the at least one through-opening gradually becomes smaller release. This in turn causes the second section to gradually separate from the resistance element, which is accompanied by a successive change in the total resistance. In this regard, the check valve acts much like a potentiometer, with the diaphragm or second portion acting as an actuator.

The resistance element is preferably arranged in a Y-direction extending transversely to the X-direction next to a passage opening. In the above-described process of successively releasing the base body along the X-direction, the release of parts of the through-hole is, as it were, parallel to release from the resistance element. Ie. the increase in the flow rate and the change in the total resistance also run in parallel, which can better determine a relationship.

Also preferably, the resistance element is arranged adjacent to a passage opening. That is, either the resistance element directly adjoins the passage opening, or there is a gap which, however, is significantly smaller than an extension of the resistance element or the passage opening in the corresponding direction, ie, for example, at most 20% or 30%. On the one hand there is a closer relationship between the release of the resistance element and the release of the passage opening, on the other hand, the membrane can be optimized in terms of their area, since they cover at least the passage opening and must touch the resistance element. In this context, it is advantageous if there is no larger gap between the passage opening and the resistance element.

Advantageously, an end of the resistance element facing away from the first section in the X direction extends at least as far as the at least one passage opening. In other words, the end of the resistive element farthest from the first portion in the X direction is at least as far away as the farthest end of each through hole. The advantage with this arrangement is that even if only the farthest end of the through-hole is released by lifting off the second portion of the membrane, this will in any case lead to a detachment of the second portion from a part of the resistance element. This in turn brings about a change in the total resistance, so that even a minimum release of a part of a passage opening is electrically detectable.

It is likewise advantageous if an end of the resistance element facing the first section of the membrane extends in the X direction at least as far as the first section. That is, the resistance element extends in this direction at least to the end of the second portion. As a result, even if the second portion is almost completely detached from the base body, slight changes in position of the second portion are still electrically detectable.

In principle, the invention can be realized with exactly one passage opening and exactly one resistance element. In a preferred embodiment of the invention, the base body has at least two passage openings, between which the resistance element is arranged. It is preferred that the resistance element is arranged along the Y-direction between the two passage openings. In such an arrangement, the membrane can, for example, be flown symmetrically, which usually also leads to a symmetrical or uniform lifting of the through holes. The two passage openings and the resistance element can in this case extend strip-like adjacent to each other in the X direction.

In the case of exactly one passage opening, it may be advantageous to provide two resistance elements, between which the passage opening is arranged. Otherwise, in the case of only one resistance element, it could happen, for example, in the case of a slight, asymmetrical lifting of the membrane, that this can not be detected because it takes place on the side of the membrane opposite the resistance element.

Basically, it is sufficient for the function of the check valve that the membrane is flexible, where they can possibly be easily guided by the flowing fluid or the pressure difference in the closed position or can be held in this. In order to enable a reliable closing of the passage opening, however, it is preferred that the second section is elastically deflectable from the closed position. That is, due to a pressure difference across a fluid, the second portion may be deflected to release the through-hole, but this deflection is elastic, which means that a restoring force occurs, by which the second portion is returned to the closed position. as soon as no external pressure difference or external force is applied. The closed position may in this case correspond to a relaxed position of the second section or the second section may be biased in the closed position against the base body. In order to realize the elastic deflectability, in particular the membrane itself may be formed elastically. Alternatively, an additional return element could be provided that acts on the membrane.

Advantageously, the second electrical contact is arranged on an end of the resistance element opposite the first electrical contact. One could therefore say that the second electrical contact is arranged at the outermost end of the resistance element. This maximizes the spatial distance between the two electrical contacts. Normally, those parts of the resistance element which are farther away from the first electrical contact than the second electrical contact are not or only to a small extent flowed through by current or have little influence on the total resistance. Thus, the embodiment described here corresponds to an optimal utilization of the entire resistance element.

As already indicated above, the check valve can act as a kind of potentiometer, through the resistance of which the flow can be measured. It is advantageous in terms of sensitivity, if the smallest possible change in the flow leads to the largest possible change in the resistance. On the one hand, this can be influenced by the choice of specific resistances of the resistive element and the conductive membrane. On the other hand, the geometry of the at least one passage opening can also play a role here. Thus, it is advantageous if at least one passage opening in the X direction has a greater extent than in the Y direction. In particular, the corresponding extent, for example, be at least twice or at least five times. It could also be said that the cross section of the passage opening is elongated in the X direction or narrow in the Y direction. It is also advantageous here that in the event that the second section separates asymmetrically (ie on one side of the through-hole further detaches than on the other side), thus an associated measurement error thus less. It is also often the case that such an asymmetrical detachment occurs less frequently or is less pronounced in the case of a plurality of through openings.

From the aspect of a possible asymmetrical detachment of the second section, it may also be advantageous if at least one resistance element has a greater extent in the X direction than in the Y direction. Again, the corresponding extent, for example, be at least twice or at least five times.

As already mentioned above, with regard to the specific resistances of the membrane and of the resistance element, there are basically no particular restrictions. Advantageously, however, the membrane has a smaller specific resistance than the resistance element. In particular, the specific resistance can be significantly smaller, for example, ten times or one hundred times. In such an embodiment, the total resistance is determined predominantly by the proportion of the resistance element to which the second portion of the membrane is not applied. The remaining parts of the resistor element are effectively bridged by the membrane.

The way in which the total resistance changes upon detachment of the second section can be influenced by the geometry of the resistance element. Thus, for example, in the case of a parallelepiped-shaped resistance element whose specific resistance is significantly greater than that of the membrane, a substantially linear relationship would result. According to an alternative embodiment, at least one resistance element has an extension in the Y direction and / or in the Z direction, which changes along the X direction. If one looks at the extension in the X direction as the length of the resistance element, its width (in the Y direction) and / or its thickness (in the Z direction) can thus change. The corresponding extent may, for example, change linearly or else non-linearly as a function of the X coordinate.

The check valve according to the invention can be integrated in a variety of systems in which the actual valve function is to be combined in a space-saving and cost-effective manner with a measurement of the flow. For example. For example, in a brake booster system, the check valve may be inserted in a communication line between a brake booster and a vacuum source (a mechanically or electrically operated vacuum pump or the intake manifold of the engine). This makes it possible to determine the flow in a simple manner. This opens up various possibilities, for example a detection of leaks in the system, without making an immediate pressure measurement within the brake booster. Thus, the expected pressure in the brake booster can be indirectly determined or estimated. From the expected pressure in the brake booster and the pressure in the vacuum source, an expected flow can be derived. If this expected flow does not match the measured flow, it can be concluded that there is a leak. This is advantageous over systems in the prior art, which rely on an immediate pressure measurement in the brake booster for such a fault diagnosis, which is complicated and costly due to the pressure sensor to be integrated there. In contrast, the check valve according to the invention is inexpensive and can be easily integrated.

Further advantageous details and effects of the invention are explained in more detail below with reference to exemplary embodiments illustrated in the figures. Show it:

1 a schematic representation of a first embodiment of a check valve according to the invention in a closed position;

2 a schematic representation of a portion of the check valve 1 ;

3 a schematic representation of the check valve 1 in a first passage position;

4 a schematic representation of the check valve 1 in a second passage position; such as

5 a schematic representation of part of a second embodiment of a check valve according to the invention;

In the different figures, the same parts are always provided with the same reference numerals, which is why these are usually described only once.

1 schematically shows a perspective view of a first embodiment of a check valve according to the invention 1 , The check valve 1 has a base body 2 on top of which an electrically conductive membrane 3 is attached. More precisely, this is a first section 3.1 the membrane, for example, by gluing on the base body 2 attached, while in the present example, in terms of area considerably larger second section 3.2 opposite the base body 2 is mobile. It can the second section 3.2 be bent and so on a surface 2.1 be lifted off the base body. The two sections 3.1 . 3.2 are arranged successively in an X direction. The first paragraph 3.1 has a first electrical contact 7 on that with a circuit 9 connected is.

The base body 2 is shown here with rectangular cross-section, which is to understand, however, purely schematic. It may, for example, also have a round cross section and be provided with threaded elements or holes for screws, by means of which it can be fastened within a fluid line.

The further structure of the check valve 1 is related to the partial view in 2 explains in which the membrane 3 was omitted. The base body 2 has two passage openings 4 . 5 each having a rectangular cross section, which are elongated in the X direction, which means in this case that their extension in the X direction is approximately five times an extension in transverse Y direction. The two passage openings 4 . 5 serve to a fluid, eg. Air, through the base body 2 let through. The intended flow direction of the fluid corresponds to a direction perpendicular to the X direction and the Y direction Z direction. However, the fluid is on the side of the membrane 3 a higher pressure on, the through holes 4 . 5 through the membrane 3 closed, ie the check valve 1 located in one of the 1 illustrated closed position.

Between the passage openings 4 . 5 a web is formed on which a resistance element 6 is arranged. The resistance element 6 has the shape of a rectangular, comparatively thin layer (for example, a metal oxide layer) applied to the surface of the ridge. The resistivity of the resistive element 6 may in this case, for example, at least by a factor of 10 be greater than the specific resistance of the membrane 3 , The resistance element 6 extends in the X direction over the entire length of the through holes 4 . 5 , It extends from the first section 3.1 opposite end 6.2 of the resistance element 6 as far in the X-direction as the through holes 4 . 5 while one the first section 3.1 facing end 6.1 up to the first section 3.1 extends. The resistance element 6 fills almost the entire width of the web and is thus to both through holes 4 . 5 adjacent. At the end 6.2 is a second electrical contact 8th arranged, which is also connected to the circuit 9 connected is.

The circuit 9 is between the first electrical contact 7 and the second electrical contact 8th through the conductive membrane 3 and the resistance element 6 closed, on which the membrane 3 is applied. As the resistivity of the resistive element 6 is significantly larger than that of the membrane 3 , will be in the in 1 shown closed position the resistance element 6 in a sense through the membrane 3 bridged. Thus, the total resistance between the two electrical contacts determined 7 . 8th mainly due to the resistance of the membrane 3 , The resistance can be measured by a measuring device 10 be determined, for example, includes a voltage source and the current in the circuit 9 measures.

The membrane 3 consists of an elastic material, the second section 3.2 in the in 1 shown closed position against the base body 2 is biased. He is, however, through one of the passageways 4 . 5 acting fluid pressure elastically deflected from the closed position, so that it is completely or partially from the surface 2.1 of the base body 2 and the resistance element 6 takes off. Such a condition is in 3 shown the the check valve 1 in a first passage position shows. Here is the second section 3.2 to a small extent elastically bent, leaving it from the surface 2.1 is lifted off. This is part of the passage openings 4 . 5 released, which can lead to a flow of the fluid. For example, a (generally non-linear) relationship between the released area and the flow may be determined experimentally. This makes the second section 3.2 from the surface 2.1 takes off, there is also a partial detachment from the resistance element 6 , This in turn leads to that part of the resistance element 6 who is no longer in contact with the membrane 3 is no longer bridged and thus contributes significantly to the overall resistance. A corresponding increase in resistance may be provided by the measuring device 10 be registered.

In 4 is shown a further passage position, where the flow is opposite 3 is increased, resulting in a further replacement of the second section 3.2 from the surface 2.1 and the resistance element 6 accompanied. On the one hand, this results in a larger proportion of the passage openings 4 . 5 released, on the other hand is the membrane 3 on an even smaller part of the resistance element 6 at. Only this smaller part is thus bridged in the sense described above, which leads to a further increase in the total resistance.

For the case described that the resistivity of the resistive element 6 is much larger than that of the membrane 3 , the total resistance at the in 1 - 4 shown check valve 1 nearly proportional to the released area of the passage openings 4 . 5 , 5 shows a further embodiment of a check valve 1a in which this is not so. Here again is like in 2 the membrane 3 omitted. This check valve 1a is largely the same as in 1 - 4 shown and will not be described again. However, in this case has a resistance element 6a an extension in the Y direction that changes along the X direction. This has the resistance element 6a a substantially trapezoidal, triangular shape, wherein it is in the direction of the first section 3.1 rejuvenated. Since the resistance contribution of the tapered parts is greater due to the smaller cross section, the total resistance changes overall non-linearly with the released area of the through holes 4 . 5 ,

LIST OF REFERENCE NUMBERS

1, 1a

 check valve

2

 base body

2.1

surface

3

 membrane

3.1

first section

3.2

second part

4, 5

 Through opening

6, 6a

 resistive element

6.1, 6.2

The End

7, 8

 electric contact

9

 circuit

10

 measuring device

X

 X-direction

Y

 Y-direction

Z

 Z-direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• GB 954048 A [0005]
• US 3587326 A [0006]
• US 8800473 B1 [0007]
• US 3914994A [0008]
• US 4926903 A [0009]
• US Pat. No. 4,213,021 A [0010]
• US 2008/0053537 A1 [0011]

Claims (10)

Check valve ( 1 . 1a ) with - a base body ( 2 ) with at least one passage opening ( 4 . 5 ), - an electrically conductive membrane ( 3 ), which successively along a X-direction a first, attached to the base body portion ( 3.1 ) with a first electrical contact ( 7 ), and a second, movable section ( 3.2 ), wherein the base body ( 2 ) at least one extending in the X direction electrode ( 6 . 6a ) which is connected to a second electrical contact ( 8th ), and wherein in a closed position the membrane ( 3 ) the at least one passage opening ( 4 . 5 ) and the second section ( 3.2 ) adjacent to the at least one electrode ( 6 . 6a ) is arranged. Check valve according to claim 1, characterized in that (as an electrode, at least one extending in the X-direction resistive element 6 . 6a ) on the base body ( 2 ) is arranged, wherein in the closed position of the second section ( 3.2 ) on the resistance element ( 6 . 6a ) is present. Check valve according to claim 2, characterized in that the resistance element ( 6 . 6a ) in a transverse to the X direction Y-direction next to a through hole ( 4 . 5 ) is arranged. Check valve according to one of the preceding claims, characterized in that one of the first section ( 3.1 ) opposite end ( 6.2 ) of the resistive element ( 6 . 6a ) extends in the X direction at least as far as the at least one passage opening ( 4 . 5 ). Check valve according to one of the preceding claims, characterized in that a first section ( 3.1 ) facing end ( 6.1 ) of the resistive element ( 6 . 6a ) in the X direction at least until the first section ( 3.1 ). Check valve according to one of the preceding claims, characterized in that the base body ( 2 ) at least two through holes ( 4 . 5 ), between which the resistance element ( 6 . 6a ) is arranged. Check valve according to one of the preceding claims, characterized in that the second section ( 3.2 ) is elastically deflectable from the closed position. Check valve according to one of the preceding claims, characterized in that the second electrical contact ( 8th ) at a first electrical contact ( 7 ) opposite end ( 6.2 ) of the resistive element ( 6 . 6a ) is arranged. Check valve according to one of the preceding claims, characterized in that at least one passage opening ( 4 . 5 ) has a greater extent in the X direction than in the Y direction. Check valve according to one of the preceding claims, characterized in that at least one resistance element ( 6 . 6a ) has an extension in the Y direction and / or in the Z direction, which changes along the X direction.

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