Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N15/06—Investigating concentration of particle suspensions
  • G01N15/0656—Investigating concentration of particle suspensions using electric, e.g. electrostatic methods or magnetic methods
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
  • F01N2560/05—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being a particulate sensor

Definitions

• 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
• the known particle sensor has a complex layer structure with a multiplicity of individual layers of comparatively complex geometry.
• 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.
• Sensor electrode disposed on a first electrically insulating body
• 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.
• the bodies may also be considered as carriers for the relevant electrode (s).
• the said fluid flow may be around a
• the particles may be soot particles, such as those produced as part of combustion of fuel by an internal combustion engine.
• the first and / or second body is a
• Ceramic body which can be advantageously prepared for example by means of ceramic injection molding (CIM).
• CIM ceramic injection molding
• 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.
• the particle charging device is designed to generate a corona discharge.
• the particle charging device is designed to generate a corona discharge.
• High voltage electrode and at least one counter electrode are provided.
• 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
• the high voltage electrode has at least one needle-shaped electrode or tip.
• 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.
• 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).
• the first body has a substantially circular cross-sectional shape.
• the second body is substantially cylindrical ("cylinder-like"), and thus may preferably be a cylinder-like body
• 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).
• both bodies are substantially cylindrically shaped, and optionally at least one of them has a radius varying over the height.
• 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.
• the second body in a first axial end region, 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
• 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.
• 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.
• one or more trap electrodes can be provided for deflecting comparatively lightly charged particles in this area.
• At least one trap electrode may also be provided.
• the second electrically insulating body is arranged substantially coaxially to the first body, protrudes in particular at least partially into the first body.
• this advantageously defines a channel for guiding a fluid, for example exhaust gas.
• 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.
• 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.
• 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
• the 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,
• 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
• FIG. 3 schematically shows a cross section of a further embodiment of the particle sensor
• FIG. 4 schematically shows a simplified flowchart of a
• 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.
• 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
• 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
• the high voltage electrode 1 12 has at least one needle-shaped electrode or tip.
• 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.
• 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.
• 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.
• 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.
• 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
• Tip structures formed high-voltage electrode 1 12 train.
• the high voltage counter electrode 1 14 is particularly preferred.
• 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.
• Sensor electrode 120 disposed on the inner surface 102 a of the first body 102.
• the sensor electrode 120 can be directly on the surface
• 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.
• the maximum radial outer dimension corresponds to the outer diameter D1
• the minimum radial dimension of the inner space I of the first body 102 corresponds to the inner diameter D2.
• Particle charger 1 10 can record.
• 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.
• comparatively lightly charged particles ions of a gas contained in the fluid flow A1, A1 '
• Trap electrode 130 indicated by a dashed line, which is arranged on the outer surface 104a of the second body 104.
• 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
• 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 are upstream particle charging devices 110 and the downstream sensor electrode 120.
• the invention 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.
• 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.
• 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.
• 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.
• 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
• 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).
• 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.
• 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 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 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.
• 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
• Needle electrode structures 1 122 Needle electrode structures 1 122.
• 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
• 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
• 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.
• Electrode areas are generated. Also the attachment of e.g.
• 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.
• the second body 104 ' is also held by the first body 102, resulting in a particularly simple construction.
• 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).
• the first body 102 has at least one opening 1022 in a wall 102 'of the hollow cylindrical one
• Particle sensor 100a can get into the interior I of the first body 102.
• 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.
• 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.
• the combined high voltage and trap electrode 1 12a may also be used as a discrete device, for example.
• 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.
• High-voltage electrode and at least one trap electrode may be provided.
• 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.
• the supply line of the sensor electrode can run in isolation below the counterelectrode 1 140 (for example produced by means of multilayer electrodes)
• 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.
• 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.
• the particulate sensor 100 is protected from direct contact with the main exhaust flow A.
• the function of the radially outer tube R2 for example, by the tubular guide member
• 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
• a particulate-containing fluid eg exhaust gas
• a particulate-containing fluid eg exhaust gas
• the particle sensor can advantageously be used for example for monitoring a diesel particulate filter of a self-igniting internal combustion engine.
• 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.
• 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.
• spark-ignited internal combustion engines for example "gasoline vehicles”
• particulate matter measurement capability is also particularly important for gasoline vehicles.
• 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.
• 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
• 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).
• the particle sensor may be used particularly advantageously for a legally prescribed ODB (Onboard Diagnosis) monitoring of the state of a diesel particulate filter.
• ODB Onboard Diagnosis
• Particle sensors 100, 100a dar This is also the use in
• Gasoline vehicles for GPF particle filter for gasoline vehicles monitoring possible.
• the higher measurement speed also allows a correlation of a raw measurement signal with engine operating points, which is a
• the principle of the present embodiments 100, 100a addresses in particular the problem of reducing a disturbing influence of
• the design described above with the two separate bodies 102, 104 is proposed, in which e.g. is about body of a ceramic material.
• 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
• 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 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

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• 2017
  • 2017-08-15 DE DE102017214194.8A patent/DE102017214194A1/de not_active Withdrawn
• 2018
  • 2018-07-31 CN CN201880052795.7A patent/CN110998283A/zh active Pending
  • 2018-07-31 WO PCT/EP2018/070693 patent/WO2019034408A1/de unknown
  • 2018-07-31 EP EP18749765.6A patent/EP3669167A1/de not_active Withdrawn
  • 2018-07-31 KR KR1020207004464A patent/KR20200039692A/ko not_active Application Discontinuation

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