EP3669167A1

EP3669167A1 - Particle sensor and method for producing same

Info

Publication number: EP3669167A1
Application number: EP18749765.6A
Authority: EP
Inventors: Radoslav Rusanov
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-08-15
Filing date: 2018-07-31
Publication date: 2020-06-24
Also published as: WO2019034408A1; DE102017214194A1; CN110998283A; KR20200039692A

Abstract

The invention relates to a particle sensor (100; 100a) having a particle charging device (110), which has a high-voltage electrode (112) and is intended to charge particles (P) in a fluid flow (A1), and having at least one sensor electrode (120) for capturing information relating to an electrical charge current caused by particles from the fluid flow (A1), characterized in that the sensor electrode (120) is arranged on a first electrically insulating body (102), and in that the high-voltage electrode (112) is arranged on a second electrically insulating body (104; 104') which differs from the first electrically insulating body (102).

Description

Description title

Particle sensor and manufacturing method for this state of the art

The invention relates to a particle sensor with a one

High-voltage electrode having particle charging device for charging particles in a fluid stream, and at least one sensor electrode for detecting information about an electric charge flow caused by particles, in particular charged particles, from the fluid flow, and a method for producing such a particle sensor.

WO 2013/125181 A1 discloses a particle sensor for use in

Cars known. The known particle sensor has a complex layer structure with a multiplicity of individual layers of comparatively complex geometry.

Disclosure of the invention

Accordingly, it is an object of the present invention to improve a particle sensor of the type mentioned and a manufacturing method thereof to the effect that the particle sensor has increased precision and a comparatively simple structure and is inexpensive to manufacture.

This object is achieved by the particle sensor according to claim 1 and the method according to claim 10. The particle sensor according to the invention has a particle charging device with a high-voltage electrode for charging particles in a fluid flow, and at least one sensor electrode for detecting information about an electric charge flow, which is caused by charged particles from the fluid flow. According to the invention Sensor electrode disposed on a first electrically insulating body, and the high voltage electrode is disposed on a second electrically insulating body, which is different from the first electrically insulating body. The arrangement of the sensor electrode and the high voltage electrode on the two different electrically insulating bodies results in a particularly low-noise operation, in particular interference from the high voltage electrode to the sensor electrode or possibly their electrical supply to the known systems are reduced. As a result, a particularly sensitive and accurate particle sensor can be provided. Next, a particularly simple structure and a cost

Production. The bodies may also be considered as carriers for the relevant electrode (s).

For example, the said fluid flow may be around a

Exhaust flow of an internal combustion engine of a motor vehicle act.

For example, the particles may be soot particles, such as those produced as part of combustion of fuel by an internal combustion engine. In a preferred embodiment, the first and / or second body is a

Ceramic body, which can be advantageously prepared for example by means of ceramic injection molding (CIM). In further preferred embodiments, in-mold labeling methods for producing the first and / or second body can also be used, wherein advantageously, for example, the high-voltage electrode or the sensor electrode and / or further electrodes or electrical electrodes

Connecting lines and the like can be applied to the body or bodies. This also comparatively complex structures can be provided with relatively low production costs.

In preferred embodiments, the particle charging device is designed to generate a corona discharge. In particular, the

High voltage electrode and at least one counter electrode

The corona discharge allows electrical charging of particles or particles in general, including gases, from the fluid flow or exhaust gas flow in a space around the High voltage electrode. This will be on the one hand particles directly at

Flowing through the region of the corona discharge electrically charged. On the other hand, particles are charged via charged particles of the gas or exhaust gas stream, with the gas or exhaust gas stream being charged directly as the space flows through in the area of the high-voltage electrode. This overall improves the efficiency of charging. In a preferred embodiment, the high voltage electrode has at least one needle-shaped electrode or tip.

In preferred embodiments, the first body is formed substantially hollow cylindrical, thus preferably a cylinder-like body with cavity (the cavity may also be shaped like a cylinder), also along the height of the body. In particular, in further embodiments, the base surfaces of the body and the cavity i.w. be arbitrary and different from one another, and in particular also change over the height (i.e., along a height coordinate of the body).

In preferred embodiments, the first body has a substantially circular cross-sectional shape.

In further preferred embodiments, the second body is substantially cylindrical ("cylinder-like"), and thus may preferably be a cylinder-like body

Embodiments The base of the second body i.w. be arbitrary and in particular also change over the height (i.e., along a height coordinate of the second body).

In a particularly preferred embodiment, both bodies (first and second bodies) are substantially cylindrically shaped, and optionally at least one of them has a radius varying over the height.

In further preferred embodiments, the high-voltage electrode is arranged at least partially within an inner space of the first body, and in particular a counterelectrode for the high-voltage electrode is arranged on an inner surface or inner wall of the first body, in particular on the inner surface or inner wall, resulting in a particularly efficient and uniform charging of particles.

In further preferred embodiments, the at least one

Sensor electrode on one or the inner surface or inner wall of the first

Body arranged, in particular on the inner surface or inner wall. For example, the sensor electrode can be arranged flat on the inner surface. In further preferred embodiments, in a first axial end region, the second body has a maximum radial outer dimension that is less than a minimum radial dimension of an interior of the first body. This advantageously makes it possible to insert the second body at least partially, in particular with a first axial end region, axially into the first body. For example, at a substantially

circular cylindrical formed basic shape of the second body, the maximum radial outer dimension correspond to an outer diameter, wherein optionally the minimum radial dimension of the first body corresponds to an inner diameter. In this configuration, by the at least partial arrangement of the two bodies, a functional space between a radially outer surface of the second body and a radially opposite inner surface of the first body is defined which can receive, for example, electrodes of the particle charging device. Optionally, one or more trap electrodes can be provided for deflecting comparatively lightly charged particles in this area.

In further embodiments, which do not provide an arrangement with one another or a different arrangement of the two bodies than described above by way of example, optionally at least one trap electrode may also be provided.

In further preferred embodiments, the second electrically insulating body is arranged substantially coaxially to the first body, protrudes in particular at least partially into the first body. In addition to the above-described definition of the functional areas for the electrodes, this advantageously defines a channel for guiding a fluid, for example exhaust gas. In further preferred embodiments, the

High voltage electrode at least one of the following structures: substantially planar needle electrode structures, which are preferably arranged on at least one outer surface of the second body,

Needle electrode structures, which are preferably arranged on at least one outer surface of the second body and protrude from the outer surface, that protrude from the outer surface. Combination of both variants are also conceivable. These embodiments enable efficient generation of a corona discharge, with the respective electrode structures being easy to manufacture at the same time.

In further preferred embodiments, the second body is arranged completely in one or the interior of the first body, preferably held by the latter, resulting in a particularly small-sized configuration.

In further preferred embodiments, the first body has at least one opening in a wall of the hollow cylindrical basic shape, whereby advantageously fluid, in particular particles to be detected containing exhaust gas or the like, can pass from a radially outer environment of the particle sensor into the interior of the first body.

Another aspect of the present invention has a method of manufacturing a particulate sensor having a high voltage electrode

Particle charging device for charging particles in a fluid flow to the object. The particle sensor has at least one sensor electrode for detecting information about an electric charge flow caused by particles from the fluid flow. The method comprises the following steps: providing a first electrically insulating body,

Disposing the sensor electrode on the first electrically insulating body; providing a second electrically insulating body different from the first electrically insulating body;

High voltage electrode on the second electrically insulating body.

Other features, applications and advantages of the invention will become apparent from the following description of embodiments of the invention, which are illustrated in the figures of the drawing. All described or illustrated features alone or in any combination form the subject matter of the invention, regardless of their

Summary in the claims or their dependency and regardless of their formulation or representation in the description or in the drawing.

In the drawing shows:

FIG. 1 schematically shows a cross section of a first embodiment of the particle sensor according to the invention,

FIGS. 2A, 2B schematically each show a plan view of details of a

Particle sensors according to further embodiments,

FIG. 3 schematically shows a cross section of a further embodiment of the particle sensor,

FIG. 4 schematically shows a simplified flowchart of a

Embodiment of the method according to the invention, and

FIG. 5 schematically shows the arrangement of the particle sensor according to FIG. 1 in a target system.

FIG. 1 schematically shows a cross section of a first embodiment of a particle sensor 100 according to the invention. The particle sensor 100 has a particle charging device 110 for charging particles P in a fluid flow A1. The particle charging device 110 has at least one

High voltage electrode 1 12, which with a comparatively large electric potential, for example a few 100 volts or a few kilovolts, can be acted upon to produce a corona discharge 1 13. The

High voltage electrode 1 12 is associated with a high voltage counter electrode 1 14, which is connectable to a reference potential, for example, the ground potential GND. The corona discharge 1 13 forms advantageous in particular in a space between the high voltage electrode 1 12 and the high voltage counter electrode 1 14 from.

The corona discharge 13 allows charging of particles P or generally particles, e.g. also of gases, from the fluid flow or exhaust gas flow

A1, A1 'in a space around the high voltage electrode 1 12. Thus, on the one hand, particles P directly when flowing through the

High voltage electrode 1 12 surrounding room area area loaded. On the other hand, particles are charged via charged particles of the gas or exhaust gas flow A1, A1 ', wherein the gas or exhaust gas flow directly as it flows through the

Space region of the high voltage electrode 1 12 has been loaded. This overall improves the efficiency of charging. In a preferred embodiment, the high voltage electrode 1 12 has at least one needle-shaped electrode or tip.

Further according to the invention, the particle sensor 100 has at least one

Sensor electrode 120 for detecting information about an electric charge flow, which is caused by particles P from the exhaust gas stream, which were charged by means of the particle charging device 1 10.

According to the invention, the sensor electrode 120 is disposed on a first electrically insulating body 102, and the high voltage electrode 1 12 is disposed on a second electrically insulating body 104 different from the first electrically insulating body 102. In other words, the particle sensor 100 has the first electrically insulating body 102 and a second electrically insulating body 104 different therefrom, and the electrodes 1 12, 120 are respectively assigned to or arranged on different bodies 104, 102. This advantageously results in a particularly low influence of the sensor electrode 120 by the operation of the high voltage electrode 1 12, whereby precision and sensitivity of the particle sensor according to the invention over conventional configurations are significantly increased.

In preferred embodiments, the first body 102 is substantially hollow cylindrical, preferably substantially circular

Cross-sectional shape, formed, thus has a sleeve shape, which is advantageous Possibilities for arranging one or more electrodes on an inner surface 102a of the first body 102.

In further preferred embodiments, the high voltage electrode 1 12 is at least partially disposed within an inner space I of the first body 102, and in particular the high voltage counter electrode 1 14 is disposed on the inner surface 102a or inner wall of the first body 102, thereby providing a particularly efficient and uniform charging of the Particles results. It may therefore be a comparatively homogeneous corona discharge in the radial direction to the preferred at least approximately

rotationally symmetric (possibly with the exception of individual

Tip structures) formed high-voltage electrode 1 12 train.

Particularly preferred is the high voltage counter electrode 1 14 as

Ring electrode formed, that is substantially corresponds to a portion of a lateral surface of the circular cylinder, through the interior I and the

Inner surface 102a of the first body 102 is defined.

In further preferred embodiments, the at least one

Sensor electrode 120 disposed on the inner surface 102 a of the first body 102. For example, the sensor electrode 120 can be directly on the surface

Be arranged inside surface 102 a, substantially similar to the high voltage counter electrode 1 14th

In further preferred embodiments, the second body 104 has a maximum radial outer dimension in a first axial end region B1 which is smaller than a minimum radial dimension of the inner space I of the first body 102. This advantageously makes it possible for the second body 104 to be at least partially, in particular with its first axial end region B1, to insert axially into the first body 102. For example, in the case of a substantially circular-cylindrical basic shape of the second body 104, the maximum radial outer dimension corresponds to the outer diameter D1

where appropriate, where appropriate, the minimum radial dimension of the inner space I of the first body 102 corresponds to the inner diameter D2. In this configuration, as a result of the at least partial arrangement of the two bodies 102, 104, a functional space FR between a radial space is obtained

Outer surface 104a of the second body 104 and this Defines the opposite radial inner surface 102a of the first body 102, which, for example, the electrodes 1 12, 1 14 of the

Particle charger 1 10 can record. Optionally, one or more trap electrodes may be provided for deflecting comparatively lightly charged particles (ions of a gas contained in the fluid flow A1, A1 ') in this region. This causes charged particles, which do not adhere to the particles to be detected, to be trapped before reaching the sensor electrode 120 and thus can not contribute to the charge measurement. In the present case is an optional in Figure 1

Trap electrode 130 indicated by a dashed line, which is arranged on the outer surface 104a of the second body 104. In some embodiments, the optional trap electrode 130 may be subjected to the same electrical potential as the high voltage electrode 1 12, advantageously providing only a single electrical lead for

Loading the trap electrode and the high voltage electrode is required with a corresponding to the high voltage electrical potential. A counter electrode 132 for the trap electrode 130 is advantageous on

Inner surface 102 a of the first body 102 disposed, with respect to a flow direction of the fluid flow between the A1 further

upstream particle charging device 110 and the downstream sensor electrode 120.

In other embodiments (not shown in FIG. 1), it may also be provided to functionally combine the high-voltage electrode 1 12 and a trap electrode 130, for example by means of a single electrode surface, which in turn is preferably arranged on the outer surface 104 a of the second body 104. Here too, the invention remains

proposed separation of high voltage applied to be acted upon or acted upon electrodes 1 12,130 of the sensor electrode 120, realized by the arrangement on separate electrically insulating bodies 102, 104, advantageously obtained.

In further embodiments (also not shown), which no

Assembly or other than the above exemplified described arrangement of the two bodies 102, 104 provide, may also optionally be provided at least one trap electrode.

In further preferred embodiments, the second electrically insulating body 104 is disposed substantially coaxially with the first body, projects in particular at least partially into the first body 102, as shown by way of example in FIG. In the present case, the first axial end region B1 of the second body 104 protrudes into the inner space I of the first body 102, whereas the second axial end region B2 of the second body 104 does not project into the inner space I and possibly a larger one

Outside diameter than the first outer diameter D1 has. In addition to the above-described definition of the functional areas or the functional space FR for the electrodes 1 12, 1 14, 130, this advantageously defines a channel K for guiding a fluid, for example exhaust gas. Fluid exiting from the particle sensor 100 is indicated by the reference A2.

In further embodiments, an optional shielding electrode 140 is provided, for example in the form of a grid electrode, which is preferably arranged between the particle charging device 110 and the sensor electrode 120. If an optional trap electrode 130 is provided, the likewise optional shield electrode 140 is preferably arranged between the optional trap electrode 130 and the sensor electrode 120, as is indicated schematically in FIG. The shield electrode 140 may advantageously serve to shield the sensor electrode 120 from electric fields resulting from further upstream components (eg, electric fields generated by the corona discharge 13).

Particularly preferably, the particle sensor is formed in some embodiments substantially rotationally symmetrical, so that sensitivity is reduced with respect to a mounting angle in a target system.

In further preferred embodiments, corresponding to those

Detailed plan views will be described below with reference to Figures 2A, 2B, the high voltage electrode 12 (Figure 1) having at least one of the following structures: substantially planar Needle electrode structures 1 120 (FIG. 2A), which are preferably located on the

Outer surface 104a of the second body 104 are arranged,

Needle electrode structures 1 122 (FIG. 2B), which are preferably located on the

Outer surface 104a of the second body 104 are arranged and protrude from the outer surface 104a, so protrude from the outer surface, in particular perpendicular (in the present case also perpendicular to the plane of FIG. 2B). Combinations of both variants are also conceivable. These

Embodiments enable an efficient generation of a corona discharge, wherein the respective electrode structures are simultaneously easy to manufacture. The plan views according to FIGS. 2A, 2B are shown with a viewing direction in a radially inner direction of the particle sensor 100, in particular on the outer surface 104a of the second body 104, wherein additionally a part of the respective high-voltage counterelectrode 14 is additionally indicated. FIG. 2B additionally shows schematically an electrical

Connecting cable 1 10 'for the high-voltage electrode with their

Needle electrode structures 1 122.

In one embodiment, the needle electrode structures 1 120 according to FIG. 2A can be produced for example by means of screen printing, in particular platinum screen printing, that is to say by printing on the second body 104

Embodiments may be provided that the needle electrode structures 1 120 are produced alternatively or additionally by means of an in-mold labeling process, which further simplifies the production and cheaper. Particularly preferred are the needle electrode structures 1 120 in some

Embodiments shaped so that the needle tips (areas of the

Needle electrode structures having the lowest radius of curvature), in particular with respect to a longitudinal axis of the particle sensor, substantially,

preferably as closely as possible, in the region of the high voltage counter electrode 1 14 ends, causing the corona discharges 1 13 arise exactly at this point.

In one embodiment, the needle electrode structures 1 122 of FIG. 2B may be formed, for example, by a corresponding 3D (three-dimensional) shaping of "needle shapes" on the second body 104, e.g.

Molded electrode regions produced by mold labeling processes, and / or by subsequent attachment of the "needles" on otherwise flat

Electrode areas are generated. Also the attachment of e.g.

annular electrically conductive (e.g., metallic) pin-pointed member on the inner body 104 and its electrical connection to a high voltage supply lead

corresponding potential is conceivable.

FIG. 3 schematically shows a cross section of a further embodiment 100a of the particle sensor, in which the second body 104 'is designed differently than in the configuration 100 according to FIG. 1, wherein the second body 104' in the embodiment 100a according to FIG. 3 is in particular completely in the interior I of the first body 102 is arranged, resulting in a particularly small-sized configuration. Preferably, the second body 104 'is also held by the first body 102, resulting in a particularly simple construction. So here is the outer e.g. ceramic carrier formed by the first body 102, in Fig. 3 i.w. horizontally "continuous" (e.g., to a mounting frame, not shown, which may be installed in a target system, and which could be presently provided, for example, at the left end of the first body 102 in Figure 3).

In further preferred embodiments, the first body 102 has at least one opening 1022 in a wall 102 'of the hollow cylindrical one

Basic form, which advantageously fluid, in particular to detect particles P 'containing exhaust gas or the like, from an environment U of

Particle sensor 100a can get into the interior I of the first body 102.

Optionally, a substantially tubular guide element 1020, in particular guide plate, can be arranged radially outside of the first body 102, which guides the fluid or the fluid flow A1, A1 'from the environment U into the interior I, through the openings 1022. causes.

In the configuration 100a depicted in FIG. 3, a further difference from the configuration 100 according to FIG. 1 is a combined high-voltage and trap electrode 1 12a, which in turn can be acted upon by a comparatively large electrical potential, and which can be supplied, for example, via needle structures 1 120, 1 122 may require the training of a Corona discharge between the combined high voltage and trap electrode 1 12a and a corresponding counter electrode 1 140 cause. The counter electrode 1 140 is preferably arranged on the inner surface 102 a of the first body 102.

In some embodiments, the combined high voltage and trap electrode 1 12a may also be used as a discrete device, for example.

In particular, metallic conductive element or element with a metallically conductive surface, be formed, which, for example, in a radially inner opening of the second body 104 'can be inserted. In further embodiments, a plurality of electrodes for realizing at least one

High-voltage electrode and at least one trap electrode may be provided. In this case, for example, another electrically insulating element may be provided or arranged in the second body 104 '.

An electrical connection line 120 'for the sensor electrode 120 is advantageously arranged on the inner surface 102a of the first body 102 and thus spatially separated from the "high-voltage components" 1 12a, 1 120, 1 122. The electrical connection line 1 140' for the counter electrode 1 140 can be arranged in a comparable manner on the inner surface 102a.

In particular, the supply line of the sensor electrode can run in isolation below the counterelectrode 1 140 (for example produced by means of multilayer electrodes)

Screen printing structures) and is then shielded by these disturbances by the corona discharge.

Another significant advantage of the configuration 100a according to FIG. 3 is that no electrical contact between the two bodies 102, 104 'is necessary for the continuation of electrical connection lines or feed lines to a holder or mounting frame, which further simplifies the structure.

A further aspect of the present invention relates to a method for producing a particle sensor 100, 100a, for example according to the embodiments described above, which is described below with reference to the simplified flow chart according to FIG. The method includes the following steps: providing 200 of a first one electrically insulating body 102 (FIG. 1, for example, using ceramic injection molding), disposing 202 (FIG. 4) the sensor electrode 120 on the first electrically insulating body 102, providing 204 a second electrically insulating body 104 electrically remote from the first insulating body 102, arranging 206 the high voltage electrode 1 12 on the second electrically insulating body 104.

FIG. 5 shows schematically the arrangement of the particle sensor 100 according to FIG. 1 in a target system, which in the present case is an exhaust pipe R of an internal combustion engine of a motor vehicle. The particle sensor 100 is arranged in a protective tube arrangement which comprises a radially outer first tube R1 and a radially inner second tube R2 which, as shown in FIG. 5, is arranged radially offset inside the first tube R1 and possibly partially offset axially relative to the first tube R1. Due to the different lengths and the arrangement of the tubes R1, R2 relative to each other results from the

Venturi effect a suction in which the exhaust gas flow A in the exhaust pipe R causes a fluid flow P1 or A1 (Fig. 1) out of the inner tube R1 in Figure 5 in a vertical upward direction. The further arrows P2, P3, P4 indicate the continuation of this caused by the Venturi effect fluid flow through a gap between the two tubes R1, R2 through to the environment IT of the protective tube assembly towards. Overall, a comparatively uniform flow of the particle sensor 100 is effected by the arrangement shown in Figure 5, which enables efficient detection of particles contained in the fluid flow P1. In addition, the particulate sensor 100 is protected from direct contact with the main exhaust flow A. Thus, by the elements 100, R1, R2 advantageously a sensor device 1000 for

Determination of a particle concentration in the exhaust gas A specified.

In further preferred embodiments, the function of the radially outer tube R2, for example, by the tubular guide member

1020 can be realized according to Figure 3, wherein the first body 102 of the

Particle sensor 100a according to Figure 3 can advantageously take over the function of the inner tube R1, which further simplifies the construction. In such embodiments, it is further advantageous if one or more openings 1022 are annular in the first body 102

are provided to introduce a particulate-containing fluid (eg exhaust gas) in allow the interior I (Figure 3) of the particle sensor, where the particles are first charged and their charge is then measured.

The working principle of the particle sensor 100, 100a according to the

Embodiments are based on an electrical charge of the to be measured

Particle P (FIG. 1), in particular soot particles, and the subsequent detection of this charge by the sensor electrode 120. The particle sensor can advantageously be used for example for monitoring a diesel particulate filter of a self-igniting internal combustion engine. With the help of

Particle sensors, for example, the mass concentration (mg / m ³ or mg / mi) and / or the number concentration (particle / m ³ or particle / mi) of the soot particles P can be determined. Just the ability to measure the

Number concentration according to some embodiments is particularly advantageous because this is insufficiently possible with conventional systems for some applications.

In further embodiments, the particle sensor can also be used, for example, in vehicles with spark-ignited internal combustion engines, for example "gasoline vehicles", in order to detect particle emissions there, for example, it is important to be able to measure rapidly after the vehicle or internal combustion engine has started Due to the fine particles (low mass, high number), particulate matter measurement capability is also particularly important for gasoline vehicles.

From this point of view, the particle sensor according to the

Embodiments are also particularly advantageous since conventional automotive sensors currently available on the market (on-board) are not able to reliably measure the number of particles.

As already described above, preferred embodiments of the particle sensor according to the invention are based on the detection of the electric charge (or of the corresponding electric current) from previously

charged soot particles P (FIG. 1). The charge is preferably carried out by means of a corona discharge in the air or containing the particles

Fluid flow A1, the measurement of the charge, for example by the "escaping currenf principle or by charge influence (detection of a charge of the particles or the corresponding current characterizing measurement signal by the sensor electrode 120). According to some embodiments, the particle sensor may be used particularly advantageously for a legally prescribed ODB (Onboard Diagnosis) monitoring of the state of a diesel particulate filter.

Also other applications, such. the use in an exhaust system before a diesel particulate filter (ie upstream of the diesel particulate filter) for optimizing the engine control, are conceivable. Due to the novel measuring principle, a much higher sensitivity (minimum measurable particle or soot concentration) is achieved, which was not possible with the previous resistive principles (measurement of current flowing through soot). The inventively much higher measurement speed (at least 1 measurement per second compared to several minutes per measurement) and possibility of particle number measurement provide a great advantage of

Particle sensors 100, 100a dar. This is also the use in

Gasoline vehicles for GPF (particle filter for gasoline vehicles) monitoring possible. In particular, the higher measurement speed also allows a correlation of a raw measurement signal with engine operating points, which is a

Improvement of the data evaluation and thus an increase of the

Sensor accuracy results.

The principle of the present embodiments 100, 100a addresses in particular the problem of reducing a disturbing influence of

High voltage electrodes and leads to the sensor electrode 120 and its supply line. For this purpose, the design described above with the two separate bodies 102, 104 is proposed, in which e.g. is about body of a ceramic material. Advantageously, the bodies 102, 104 can be produced by means of Ceramic Injection Molding (CIM), in particular with in-mold labeling, which also has comparatively complex geometric properties

Molds allowed at low cost.

The concept proposed here also has some further advantages over other types of construction. The separation or distribution of high and

Low-voltage elements on the two different body or carrier

102, 104 brings advantages for the sensitivity and accuracy of the

Particle sensor. The ring-shaped corona discharges made possible in preferred embodiments increase the amount of charged soot particles (cross-section becomes larger) and thus the sensitivity of the sensor. The annular arrangement additionally massively reduces the sensitivity of the particle sensor 100, 100a with respect to the installation angle (cf., Fig. 5), which simplifies assembly in a target system 1000. The same holds true for the trap shaped electrodes 130, 132 in the preferred embodiments and their electric field, whereby the homogeneity of the trapping (capturing of comparatively light charged

Particles) is improved.

The particulate sensor according to the embodiments may be used, for example, as a sensor for on-board monitoring of a state of a

Diesel particulate filter of a passenger car or commercial vehicle are used. The concept allows both the determination of

Mass concentration (mg / m ³ or mg / mi) and the number concentration (particles / m ³ or particles / mi) of the emitted particles. The particulate sensor according to the embodiments may also be used for monitoring the condition of the particulate filter in gasoline vehicles. Also the

Use of the sensor for the determination of the particle concentration at other applications (indoor air quality, emissions from incinerators (private, industrial)) is conceivable.

Claims

claims

1 . Particle sensor (100, 100a) having a particle charging device (1 10) having a high-voltage electrode (1 12) for charging particles (P) in a fluid flow (A1), and at least one sensor electrode (120) for detecting information about an electric charge current, which is caused by particles (P), in particular charged particles, from the fluid flow (A1), characterized in that the sensor electrode (120) is arranged on a first electrically insulating body (102), and in that the high-voltage electrode (1 12) a second electrically insulating body (104; 104 ') which is different from the first electrically insulating body (102).

2. Particle sensor (100, 100a) according to claim 1, wherein the first body (102) is formed substantially hollow cylindrical.

The particle sensor (100; 100a) of claim 2, wherein the first body (102) has a substantially annular cross-sectional shape.

The particle sensor (100; 100a) according to claim 2 or 3, wherein the

High voltage electrode (1 12) at least partially within one

Interior space (I) of the first body (102) is arranged, and wherein in particular a counter electrode (1 14) for the high voltage electrode (1 12) on an inner surface (102 a) of the first body (102) is arranged, in particular on the inner surface (102 a ).

5. Particle sensor (100, 100a) according to claim 2, wherein the at least one sensor electrode (120) adjoins one or more of the sensor electrodes

Inner surface (102a) of the first body (102) is arranged, in particular on the inner surface (102a).

The particle sensor (100; 100a) according to at least one of claims 2 to 5, wherein the second body (104) has a maximum radial outer dimension (D1) smaller than a first axial end portion (B1) minimum radial dimension (D2) of the interior (I) of the first body (102).

A particle sensor (100; 100a) according to at least one of the preceding claims, wherein the second electrically insulating body (104; 104 ') is disposed substantially coaxially with the first body (102), in particular at least partially protruding into the first body (102).

A particle sensor (100; 100a) according to at least one of the preceding claims, wherein the high voltage electrode (1 12) has at least one of the following structures: substantially planar

Needle electrode structures (1 120) preferably disposed on at least one outer surface (104a) of the second body (104), needle electrode structures (122 2) preferably disposed on at least one outer surface (104a) of the second body (104) and of the Protrude outer surface (104 a).

The particle sensor (100; 100a) according to at least one of the preceding claims 2 to 7, wherein the second body (104 ') is completely disposed in, preferably held by, the interior space (I) of the first body (102).

0. Particle sensor (100, 100a) according to at least one of the preceding

Claims 2 to 8, wherein the first body (102) has at least one opening (1022) in a wall (102 ') of the hollow cylindrical basic shape. 1 . Method for producing a particle sensor (100; 100a) having a particle charging device (1 10) having a high voltage electrode (1 12) for charging particles (P) in a fluid flow (A1), and at least one sensor electrode (120) for detecting information about an electric charge flow caused by particles from the fluid flow (A1), characterized by the following steps: providing (200) a first electrically insulating body (102), arranging (202) the sensor electrode (120) on the first electrically insulating body (102), providing (204) a second electrically insulating body (104; 104 ') different from the first electrically insulating body (102), arranging (206) the high voltage electrode (1 12) on the second electrically insulating body ( 104, 104 ').