US20170198687A1

US20170198687A1 - Pump apparatus and particle detector having a pump apparatus

Info

Publication number: US20170198687A1
Application number: US15/399,219
Authority: US
Inventors: Dick Scholten; Ricardo Ehrenpfordt; Tjalf Pirk
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2016-01-13
Filing date: 2017-01-05
Publication date: 2017-07-13
Also published as: DE102016200256A1; CN107023470A

Abstract

A pump apparatus for gaseous media. A film is provided on a substrate and is connected to the substrate in the edge region of the film. By interaction between a magnetic device on the substrate and a magnetic device on the film, the film can be raised or lowered on the substrate. A pumping motion is thereby produced.

Description

CROSS REFERENCE

The present application claims the benefit of German Patent Application No. DE 102016200256.2 filed on Jan. 13, 2016, which is expressly incorporated herein by reference in its entirety.

FIELD

The present invention relates to a pump apparatus, in particular to a pump apparatus for gaseous media, and to a particle detector having a pump apparatus.

BACKGROUND INFORMATION

Sensors for measuring air quality are becoming increasingly important. Particle sensors that analyze a particle content in the air are used in that context, for example, to analyze air quality. Certain gas sensors make possible a qualitative or quantitative analysis of gases.
European Patent No. EP 1 530 717 A1 describes an apparatus for electronic measurement of air-related variables, for example air quality or gas concentration. One or more sensors for detecting air-related variables are accommodated for that purpose in a housing, the housing being ventilated by a fan.
In many cases, sensors for monitoring air quality require a defined air flow. This air flow must as a rule be produced actively. Components of very small dimensions are used for applications in portable consumer electronic devices, for example mobile telephones, smartphones, etc. To generate air flows in such devices, for example, a fan wheel or a membrane pump is coupled to a miniaturized electric motor.

SUMMARY

The present invention relates to a pump apparatus for gaseous media, and a particle detector.
The following is provided in accordance therewith:
A pump apparatus for gaseous media, having a substrate, a film, and a first magnetic device and a second magnetic device. The film is disposed on one side of the substrate. The edge region of the film is connected to the substrate. A volume is enclosed between the substrate and film. At least one opening is disposed between an inner space and an outer space of the volume enclosed by the substrate and film. The first magnetic device is coupled to the substrate. The first magnetic device is designed to furnish a first magnetic field. The second magnetic device is coupled to the film. The second magnetic device is designed to furnish a second magnetic field that enters into interaction with the first magnetic field of the first magnetic device. The first magnetic device or the second magnetic device furthermore encompasses an electric coil. The electric coil can generate a magnetic field, in particular the first magnetic field or the second magnetic field, when an electric current flows through the corresponding coil.
The following is also provided:
A particle detector having a particle sensor and a pump apparatus according to the present invention.
In accordance with the present invention, a controlled volume flow is used for the analysis of gaseous substances. The generation of suitable volume flows represents a challenge in particular for miniaturized applications. In accordance with the present invention, this is taken into account and an efficient pump apparatus for gaseous media is furnished. The present invention provides, for example, an electrodynamically driven pump apparatus. A space having a variable volume is formed by attaching a robust, flexible film to a rigid substrate. For this purpose, the edge region of the film is connected in maximally airtight fashion to the substrate. When a magnetic element, for example a magnetic device, which furnishes a magnetic field is disposed on the flexible film, that magnetic field can enter into interaction with a further magnetic field so as thereby to raise or lower the film that is disposed on the substrate. This motion causes the volume of the space that is formed between substrate and film to change. As a result of a (minimal) pressure difference that then occurs, air will flow through an opening between the inner space and outer space of the volume formed by the film and substrate.
If the magnetic field of the magnetic device disposed on the film, and/or the further magnetic field with which the magnetic field of the magnetic device on the film enters into interaction, is generated by the flow of current through an electric coil, deflection of the film can then be controlled in very simple fashion.
The configuration of the pump apparatus according to the present invention, having the substrate, film, and the necessary magnetic devices, can be implemented very simply and at low cost. The pump apparatus according to the present invention can thus be inexpensively manufactured specifically in high production volumes. The pump apparatus according to the present invention is also very suitable in particular for direct utilization on a circuit board of a printed circuit.
Advantageous embodiments and refinements are described herein with reference to the Figures.
In an embodiment, either the first magnetic device or the second magnetic device encompasses a permanent magnet. The permanent magnet can encompass, for example, a neodymium magnet. Thanks to the use of a permanent magnet as a first or second magnetic device, the corresponding magnetic device can furnish a constant magnetic field without requiring electrical energy for that purpose.
In an alternative embodiment, both the first magnetic device and the second magnetic device respectively encompass an electric coil. In this case both the magnetic field of the first magnetic device on the substrate, and the magnetic field of the second magnetic device on the film, are furnished by an electric coil through which current flows. This makes possible very precise control of the magnetic fields that are generated.
In an embodiment, the opening between the inner space and the outer space of the volume enclosed between the substrate and film encompasses a first valve. The use of a valve at the opening allows a flow direction of the medium delivered by the pump apparatus to be predefined.
In a further embodiment, the pump apparatus encompasses a second valve device that is disposed between the inner space and the outer space of the volume enclosed between the substrate and film. The medium delivered by the pump apparatus preferably flows through one of the two valve devices into the inner space, and through the respective other valve device from the inner space into the outer space.
In an embodiment, the first valve device and/or the second valve device is disposed at a transition region between the substrate and the film. At this transition region, which can correspond in particular to the edge region of the film, a valve structure can be formed particularly simply and efficiently by appropriate placement of the film.
In an embodiment, the first valve device and/or the second valve device encompasses a further electric coil. The further electric coil is designed to furnish a magnetic field when an electric current flows through it. The placement of a further electric coil on a valve device allows active control to be applied to the corresponding valve device. The respective valve device can thus be opened and closed in controlled fashion by application of an electric current to the electric coil. This allows reliable opening and closing of the corresponding valve device even with only very small pressure differences between the inner space and the outer space.
In an embodiment, the film encompasses a biaxially oriented polyester (boPET) film. The film can in particular encompass polyethylene terephthalate. Such films have a low weight per unit area and low stiffness, and are nevertheless highly tear-resistant. These films are therefore well suited for the pump apparatus.
In a further embodiment, the substrate of the pump apparatus encompasses a circuit board. A circuit board made of polyimide is, in particular, very well suited. In particular, a circuit board having further conductor path structures, for example in the form of printed circuits, is also well suited as a circuit board. The circuit board can furthermore also encompass further electronic components.
The embodiments and refinements above can be combined with one another if appropriate. Further possible embodiments, refinements, and implementations of the present invention also encompass combinations, not explicitly recited, of features of the invention which are described above or hereinafter with reference to the exemplifying embodiments. In particular, one skilled in the art will also add individual aspects as improvements or additions to the respective basic forms of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in further detail below based on the exemplifying embodiments shown in the Figures.

FIG. 1 schematically depicts a cross section through a pump apparatus according to an embodiment.

FIG. 2 schematically depicts a cross section through a pump apparatus according to a further embodiment.

FIG. 3 schematically depicts a cross section through a pump device according to yet another embodiment.

FIG. 4 schematically depicts a cross section through a pump apparatus having valve devices to which active control is applied, according to an embodiment.

FIG. 5 schematically depicts a particle detector having a pump apparatus according to an embodiment.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In all the Figures, identical or functionally identical elements and apparatuses are labeled with identical reference characters unless otherwise indicated.
FIG. 1 schematically depicts a pump apparatus according to an embodiment. The pump apparatus encompasses a substrate 10 and a film 20. Film 20 can be a flexible film having little stiffness. The selected film 20 has the lowest possible weight per unit area. Film 20 should in particular be as impermeable as possible to the medium being delivered. Gas-tight films are therefore particularly suitable. Biaxially oriented polyester (boPET) films have proven particularly suitable as a material for such films. Such films are produced from polyethylene terephthalate using a particular orienting process. Films of this kind are known, for example, by the commercial names Hostaphan, Mylar, or Melinex. The weight per unit area of film 20 can be in the range between 1 and 20 g/m². In particular, values from approximately 10 to 11 g/m²are possible. Values in the range around 2 g/m²or 2 to 5 g/m²are, however, also possible.
Substrate 10 is preferably a planar substrate that is less flexible as compared with film 20. Substrate 10 can be, for example, the substrate of an electrical circuit board, for example the circuit board of a printed circuit. Such circuit boards are produced, for example, from materials of the polyimide group. Such polyimides are known, for example, by the commercial name Kapton. Any other materials are, however, also suitable in principle as substrate 10. In particular, any materials that are used for the manufacture of circuit boards for printed circuits or the like are possible as substrate 10.
For pump apparatus 1, film 20 is disposed on one side of substrate 10. The extent of film 20 is as a rule smaller than the extent of substrate 10 on which film 20 is disposed. The edge of film 20 is connected to substrate 10, while the remaining region of film 20 merely rests loosely on substrate 10. For example, film 20 can be adhesively bonded to substrate 10. It is also possible, however, for film 20 to be clamped onto substrate 10 by way of a frame (not depicted) or the like. Further possibilities for fastening film 20 on substrate 10 are also possible. Film 10 is connected to substrate 10 in the edge region over the entire surface if possible. If applicable, however, individual sub-regions of the edge of film 20 can not be connected to substrate 10 so as thereby to form an opening or a valve device, as will be further explained below.
Pump apparatus 1 furthermore encompasses a first magnetic device 30. This first magnetic device 30 is disposed on substrate 10. First magnetic device 30 can be disposed, for example, as depicted in FIG. 1, on a side of substrate 10 which is located opposite the side having film 20. It is also possible, however, to dispose magnetic device 30 on the same side of substrate 10 on which film 20 is also disposed. It is furthermore also possible to embed first magnetic device 30 in substrate 10. First magnetic device 30 is disposed as centeredly as possible in that region of substrate 10 which is covered by film 20. In the embodiment according to FIG. 1, first magnetic device 30 encompasses a permanent magnet 31. Permanent magnet 31 can be, for example, a neodymium magnet or the like.
A second magnetic device 40 is also disposed on film 20 of pump apparatus 10. Second magnetic device 40 can be disposed, for example, in a side of film 20 which faces away from substrate 10. It is also equally possible, however, for second magnetic device 40 to be disposed on a side of film 20 which faces toward substrate 10. For example, second magnetic device 40 can be adhesively bonded onto film 20. In the embodiment depicted here, second magnetic device 40 encompasses an electric coil 42. When an electric current flows through this electric coil 42, that current flow brings about a magnetic field. The magnetic field of second magnetic device 40 can thus enter into interaction with the magnetic field of first magnetic device 30. Electric coil 42 of second magnetic device 40 can be connected for that purpose to a control device that is designed to feed an electric current into electric coil 42.
If the magnetic fields of first magnetic device 30 and of second magnetic device 40 are in the same direction, first magnetic device 30 and second magnetic device 40 then attract one another. In this case film 20 having second magnetic device 40 moves toward substrate 10 having first magnetic device 30. The pressure in inner space I of the volume that is formed by substrate 10 and film 20 rises as a result. The result of this pressure rise is that the medium in inner space I will flow through opening 50 in substrate 10 into outer space A.
Conversely, if the magnetic field lines of first magnetic device 30 and of second magnetic device 40 are opposite, first magnetic device 30 and second magnetic device 40 will then repel one another. The result of this is that film 20 having second magnetic device 40 will move away from substrate 10 having first magnetic device 30. The volume of inner space I increases as a result. A gaseous medium will thus flow from outer space A into inner space I.
By changing the current direction in electric coil 42 of second magnetic device 40, it is thus possible to alternatingly move film 20 away from substrate 10 and then toward substrate 10. It is thereby possible to generate a pumping motion that alternatingly generates a volume flow from outer space A into the inner space and then from inner space I into outer space A.
FIG. 2 schematically depicts a cross section through a pump apparatus 1 according to a further embodiment. Pump apparatus 1 in this embodiment corresponds substantially to pump apparatus 1 of the embodiment previously described. The embodiment depicted here differs from the embodiment previously described in that first magnetic device 30 encompasses an electric coil 32 instead of a permanent magnet. First magnetic device 30 thus constitutes an electromagnet. When an electric current flows through electric coil 32, the result thereof is a magnetic field that can enter into interaction with the magnetic field of second magnetic device 40. In this embodiment, second magnetic device 40 encompasses a permanent magnet 41. Permanent magnet 41 of second magnetic device 40 can preferably be embodied as a very thin sheet. Strong magnets in particular, for example neodymium magnets, are very well suited. Electric coil 32 of first magnetic device 30 can be implemented, for example, as a printed conductor path on substrate 10.
If a voltage is applied to electric coil 32 of first magnetic device 30, an electric current then occurs in electric coil 30 and brings about a magnetic field. By interaction between this magnetic field and the magnetic field of second magnetic device 40, film 20 can then be moved away from substrate 10 or toward substrate 10. A pumping motion can thus be generated, analogously to the embodiment previously described.
In addition, instead of a single opening 50 in substrate 10 it is also possible to provide two or more openings, so that a volume flow of the medium to be delivered flows through respective separate openings into inner space I, and from inner space I out into the outer space. Opening 50 can encompass for this purpose, for example, a first valve device 51. This first valve device 51 makes possible a unidirectional volume flow through opening 50.
For example, first valve device 50 can enable a volume flow from outer space A into inner space I, while a reverse volume flow from inner space I into outer space A is prevented by first valve device 51. Pump device 1 encompasses a further valve device 55 for the opposite flow direction. This further valve device 55 can likewise be disposed, for example, in substrate 10. Further valve device 55 enables a volume flow from inner space I into outer space A, while a reverse volume flow from outer space A into inner space I is prevented. It is also possible in principle, however, not to integrate both first valve device 51 and second valve device 55 into substrate 10, but instead to provide them at a position deviating therefrom. For example, valve devices 51, 55 can be provided at a transition region between substrate 10 and film 20. This will be further explained below.
FIG. 3 schematically depicts a cross section through a further embodiment of a pump apparatus 1. In this embodiment, both first magnetic device 30 and second magnetic device 40 each encompass a respective electric coil 32, 42. Injection of a respective electric current into electric coil 32 of first magnetic device 30 and into magnetic coil 42 of second magnetic device 40 causes a magnetic field to be respectively generated in each of the two magnetic devices 30 and 40. These two magnetic fields enter into interaction with one another so that, depending on the polarity of the two magnetic fields, first magnetic device 30 and second magnetic device 40 either attract or repel one another. Film 20 can correspondingly be moved toward substrate 10 or moved away from substrate 10.
As is also further shown in FIG. 3, first valve device 51 and/or second valve device 55 can also be disposed in an edge region of film 20. As depicted, for example, for valve device 55, it is possible for film 20 not to be fixedly connected to substrate 10 in a sub-region of the edge of film 20. Film 20 thus merely rests loosely on substrate 10 in this region. If the pressure in inner space I of pump apparatus 1 rises above the pressure in outer space A, film 20 can then lift off from substrate 10 and enable a volume flow from inner space I into outer space A. Conversely, if the pressure in outer space A is greater than the pressure in inner space I, film 20 will then drop onto substrate 10 and thus prevent a volume flow from outer space A into inner space I. As depicted, for example, for valve device 51, further configurations between film 20 and substrate 10, which conversely prevent a volume flow from inner space I into outer space A and enable a volume flow from outer space A into inner space I, are also possible. For this, for example, a portion of film 20 can be disposed over opening 50 in substrate 10.
FIG. 4 schematically depicts a cross section through a pump apparatus 1 according to a further embodiment. This embodiment differs from the embodiment previously described substantially in that valve devices 51 and 55 likewise encompass an electric coil 33 and 34. Injection of an electric current into further coils 33 and 34 of valve devices 51 and 55 likewise causes a magnetic field to be generated by those electric coils 33 and 34. These magnetic fields of further coils 33 and 34 can then enter into interaction, for example, with the magnetic field of first magnetic device 30. It is furthermore also possible for valve devices 51, 55 also to encompass, besides electric coils 33 and 34, a further magnetic device 43, 44 with which the magnetic field of coils 33, 34 of valve devices 51, 55 can enter into interaction. These further magnetic devices 43, 44 can be magnetic devices having either a permanent magnet or a further electric coil.
Active control can be applied to the respective valve devices 51, 55 as a result of interaction of the magnetic field of further coils 33, 34 with a further magnetic field, for example the magnetic field of first magnetic device 30 or of further magnetic devices 43, 44. It is thereby possible to ensure that the respective valve devices 51, 55 reliably enable or prevent a desired volume flow even in a context of only very small pressure differences between inner space I and outer space A.
For active application of control to valve devices 51, 55, it is possible in this context for the respective electric coils 33, 34 to be impinged upon by a control device (not depicted) with an electrical voltage, so that an electric current is established in the respective electric coils 33, 34 and produces a magnetic field. It is also possible, however, to couple electric coils 33, 34 of valve devices 51, 55 electrically to an electric coil 32, 42 of first or second magnetic device 30, 40. The result is that only one current source is necessary, so that the same electric current flows through electric coils 33, 34 of valve devices 51, 55 and through the electric coil of first or second magnetic device 30, 40. This on the one hand allows circuit complexity to be minimized. It also ensures that the electric current for moving film 20 up or down is synchronized with the control application to valve devices 51, 55.
By suitably selecting the orientation of the electric coils of first and second magnetic devices 30, 40 and of valve devices 51, 55, it is possible to select in controlled fashion how the corresponding valve devices 51, 55 are correspondingly opened or closed upon a motion of film 20. Depending on the direction in which electric coils 33, 34 on valve devices 51, 55 are wound, it is thus possible to establish whether the corresponding valve device 51, 55 enables or prevents a volume flow when film 20 moves toward substrate 10.
FIG. 5 schematically depicts a particle detector 2 having a pump apparatus 1 according to an embodiment. Particle detector 2 can encompass, for example, a housing 100 having a first opening 110 and a second opening 120. A flow channel 130 is disposed between first opening 110 and second opening 120. A volume flow between first opening 110 and second opening 120 can be generated in this flow channel 130 by way of a pump apparatus 1 according to the present invention. The volume flow of the medium thereby delivered flows past a sensor device 140. Sensor device 140 is designed to detect a particle concentration, or the like, in the medium flowing past. Additionally or alternatively, a gas sensor can also be provided in order to detect one or more gaseous substances in flow channel 130.
In summary, the present invention relates to a pump apparatus, in particular to a pump apparatus for gaseous media. For that purpose, a film is provided on a substrate and is connected to the substrate in the edge region of the film. By interaction between a magnetic device on the substrate and a magnetic device on the film, the film can be raised or lowered on the substrate. A pumping motion is thereby produced.

Claims

What is claimed is:

1. A pump apparatus for gaseous media, comprising:

a substrate;

a film disposed on the substrate, an edge region of the film being connected to the substrate and a volume being enclosed between the substrate and the film;

an opening disposed between an inner space and an outer space of the volume enclosed by the substrate and film;

a first magnetic device coupled to the substrate and designed to furnish a first magnetic field; and

a second magnetic device coupled to the film and designed to furnish a second magnetic field that enters into interaction with the first magnetic field;

wherein at least one of the first magnetic device and the second magnetic device includes an electric coil.

2. The pump apparatus as recited in claim 1, wherein at least one of the first magnetic device and the second magnetic device includes a permanent magnet.

3. The pump apparatus (1) as recited in claim 1, the first magnetic device (30) and the second magnetic device (40) respectively encompassing an electric coil (32, 42).

4. The pump apparatus as recited in claim 1, wherein the opening includes a first valve device.

5. The pump apparatus as recited in claim 4, further comprising:

a second valve device disposed between the inner space and the outer space of the volume enclosed between the substrate and film.

6. The pump apparatus as recited in claim 5, wherein at least one of the first valve device and the second valve device is disposed at a transition region between the substrate and the film.

7. The pump apparatus as recited in claim 5, wherein at least one of the first valve device and the second valve device includes a further electric coil designed to furnish a magnetic field when an electric current flows through the further coil.

8. The pump apparatus as recited in claim 1, wherein the film is a biaxially oriented polyester film.

9. The pump apparatus as recited in claim 1, wherein the substrate includes polyimide.

10. A particle detector, comprising:

a particle sensor; and

a pump apparatus for gaseous media, the pump apparatus including a substrate, a film disposed on the substrate, an edge region of the film being connected to the substrate and a volume being enclosed between the substrate and the film, an opening disposed between an inner space and an outer space of the volume enclosed by the substrate and film, a first magnetic device coupled to the substrate and designed to furnish a first magnetic field, and a second magnetic device coupled to the film and designed to furnish a second magnetic field that enters into interaction with the first magnetic field, wherein at least one of the first magnetic device and the second magnetic device includes an electric coil