WO2019107257A1 - Dispositif de type capteur - Google Patents

Dispositif de type capteur Download PDF

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Publication number
WO2019107257A1
WO2019107257A1 PCT/JP2018/043091 JP2018043091W WO2019107257A1 WO 2019107257 A1 WO2019107257 A1 WO 2019107257A1 JP 2018043091 W JP2018043091 W JP 2018043091W WO 2019107257 A1 WO2019107257 A1 WO 2019107257A1
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WIPO (PCT)
Prior art keywords
cover
hole
sensor
tip
flow
Prior art date
Application number
PCT/JP2018/043091
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English (en)
Japanese (ja)
Inventor
悠男 為井
貴司 荒木
浩史 野田
岳人 木全
康一 吉田
Original Assignee
株式会社デンソー
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2018180508A external-priority patent/JP6984572B2/ja
Application filed by 株式会社デンソー filed Critical 株式会社デンソー
Priority to CN201880076886.4A priority Critical patent/CN111417849B/zh
Priority to DE112018006083.7T priority patent/DE112018006083T5/de
Publication of WO2019107257A1 publication Critical patent/WO2019107257A1/fr
Priority to US16/885,648 priority patent/US11422069B2/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance

Definitions

  • the present disclosure relates to a sensor device for detecting a specific component contained in a measured gas.
  • the exhaust gas passage of the internal combustion engine is provided with an exhaust gas purification system provided with a sensor device for detecting a specific component in the exhaust gas and a purification device such as a filter device or a catalyst device.
  • the sensor device is, for example, a PM sensor for detecting particulate matter (that is, Particulate Matter; hereinafter, referred to as PM as appropriate), and is disposed at a downstream position of the filter device for PM collection and has a filter failure It is used to determine the Further, an exhaust gas sensor such as an oxygen sensor is disposed at the upstream or downstream position of the catalyst device.
  • Such sensor devices generally comprise a sensor element housed in a housing and an element cover surrounding the outer periphery of the sensor element projecting from the housing.
  • the sensor element is provided with a detection unit at the tip end (projected side end) protected by the element cover, and detects a specific component contained in the exhaust gas taken into the element cover.
  • the element cover is usually configured in the form of a single or double container.
  • the sensor cover has a dual structure of an inner cover and an outer cover, and a gas flow hole formed on the side surface of the inner cover is a sensor element having a detection portion disposed on the tip surface. Also, it is arranged on the tip side so that the assembly direction is not restricted.
  • the gas flow hole on the side surface of the outer cover is provided at a position facing the side surface of the inner cover, and the exhaust gas is introduced into the sensor element from the gas flow hole on the side surface of the inner cover through the space between both covers. The exhaust gas in contact with the sensor element flows out to the outside from a gas flow hole coaxially arranged with the sensor element on the front end surface of the inner cover and the outer cover.
  • Patent Document 1 Although the assemblability of the sensor device is improved, it has been found that the securing of the detection sensitivity or output responsiveness of the sensor element is insufficient. In particular, since the particulate matter is easily discharged at the time of startup of the internal combustion engine, for example, when the internal combustion engine starts up, etc., at which the exhaust gas has a low flow velocity, improvement in detection sensitivity of the PM sensor is desired. Due to the slowing of the gas flow, the feed flow rate of the exhaust gas containing particulate matter is reduced. Although patent document 1 also illustrates providing a flow straightening member in a gas flow hole, sufficient effect is not necessarily acquired. Similarly, when applied to an exhaust gas sensor, the output response deteriorates due to the decrease in the flow velocity of the exhaust gas.
  • the gas flow holes are arranged coaxially with the gas sensor elements on the tip surfaces of the inner cover and the outer cover, and condensed water intrudes into the inner cover from the tip end and adheres to the sensor elements.
  • water breakage there is a possibility that it may become the cause of element breakage due to water (hereinafter referred to as water breakage).
  • An object of the present disclosure is to improve the flow rate of the gas to be measured toward the detection unit of the sensor element and improve the detection performance of a specific component in the detection unit in a configuration in which the sensor element is accommodated in the element cover of double structure. It is an object of the present invention to provide a highly reliable sensor device capable of suppressing water cracking.
  • a sensor element including a detection unit that detects a specific component in a gas to be measured; A housing for inserting the sensor element inside and holding the detection unit so as to be positioned on the tip side in the axial direction; An element cover disposed on the front end side of the housing;
  • the element cover is a sensor device having an inner cover disposed so as to cover the tip side of the sensor element, and an outer cover disposed with a space outside the inner cover,
  • the inner cover is provided with an inner side hole and an inner end surface hole through which the gas to be measured flows on the side surface and the tip surface, respectively.
  • the outer cover is provided with a plurality of outer side holes through which the gas to be measured flows on the side surface, and the tip position of the outer side hole is on the tip side of the tip position of the inner cover, and the tip surface of the outer cover Form a first flow path in which the gas flow direction is the direction orthogonal to the axial direction,
  • the inner side hole opens in a second flow path provided between the outer side surface of the inner cover and the inner side surface of the outer cover, and inclines inward of the inner cover from the tip edge portion of the inner side hole
  • a guide body is provided, and a detection surface on which the detection unit is disposed is located on an extension of the extension direction of the guide body.
  • the gas to be measured flows into the inside of the element cover from the outer side surface hole of the outer cover, passes through the first flow path between the end surface of the inner cover and in the opposing direction of the gas flow. While going to the located outer side hole, a part of it flows into the second flow passage between the outer cover and the side of the inner cover.
  • the gas flow that has reached the inner side hole opened in the second flow path is a jet flow along the guide body, and is directed to the detection surface on the extension line thereof, so that the decrease in the flow velocity is suppressed.
  • the inner side hole is opened to the second flow passage, so that gas exchange is efficiently performed.
  • the gas to be measured whose flow rate is increased can be introduced from the inner side hole toward the detection unit, so that the supply flow rate to the detection unit can be increased to improve the detection sensitivity or output responsiveness.
  • the gas flow holes are not required on the front end surface of the outer cover, direct flow of the gas to be measured into the inner front end surface holes of the inner cover can be suppressed, and the water break of the sensor element can be prevented.
  • the flow velocity of the gas to be measured toward the detection portion of the sensor element is improved to detect the specific component in the detection portion It is possible to provide a sensor device excellent in reliability by improving performance and suppressing water-drops.
  • FIG. 1 is an enlarged sectional view of an essential part in the axial direction of the PM sensor in the first embodiment
  • FIG. 2 is a schematic view showing a positional relationship between a guide body provided on an inner cover of a particulate matter detection sensor and a detection surface of a sensor element in Embodiment 1
  • FIG. 3 is an axial cross-sectional view showing a schematic configuration of the PM sensor in the first embodiment
  • FIG. 4 is a diagram showing an example of a schematic configuration of an exhaust gas purification system including a PM sensor in the first embodiment
  • FIG. 5 is an overall perspective view showing an example of a sensor element of a PM sensor according to Embodiment 1.
  • 6 is an overall perspective view showing another example of the sensor element of the PM sensor in the first embodiment
  • FIG. 7 is an enlarged sectional view of an essential part in the radial direction, including an example of the sensor element of the PM sensor in the first embodiment
  • FIG. 8 is an enlarged sectional view of an essential part in the radial direction, including another example of the sensor element of the PM sensor in the first embodiment
  • FIG. 9 is an enlarged sectional view of an essential part for explaining the gas flow in the element cover of the PM sensor in the first embodiment
  • FIG. 10 shows the effect of the gas flow (a) due to the arrangement of the outer side surface holes of the element cover in Embodiment 1 in comparison with the gas flow (b) when the arrangement of the outer side surface holes is changed
  • FIG. 11 is a schematic view of the gas flow inside the element cover having the guide body in the first embodiment, based on the result of CAE analysis, as compared with the gas flow inside the conventional element cover having no guide body.
  • Fig. 7 is an enlarged cross-sectional view of the main part of the particulate matter detection sensor shown in FIG. 12 is a diagram comparing and showing the relationship between the pipe flow velocity and the directivity in the presence or absence of a guide body in the evaluation test of directivity, FIG.
  • FIG. 13 is a diagram showing the relationship between the rise time of the output and the detected current in the directivity evaluation test
  • FIG. 14 is a schematic view of an evaluation device for explaining a test method in the evaluation test of water permeability
  • FIG. 15 is an enlarged sectional view of an essential part of a PM sensor provided with a conventional element cover in the evaluation test of water permeability
  • FIG. 16 is a view comparing the maximum water coverage of the PM sensor of Embodiment 1 and a PM sensor having a conventional element cover in a water resistance evaluation test
  • FIG. 17 is a view showing the positional relationship between the extension direction of the guide body of Test Example 1 and the sensor element in the evaluation test of the guide body in comparison with the positional relationships of Comparative Examples 1 and 2;
  • FIG. 18 is a cross-sectional view showing a schematic configuration of an evaluation device for flow rate measurement in an evaluation test of a guide body
  • FIG. 19 is a view comparing the flow rate of Test Example 1 with the flow rates of Comparative Examples 1 and 2 in the evaluation test of the guide body
  • FIG. 20 is an enlarged sectional view of an essential part of the PM sensor in which the ratio of the length in the extension direction of the guide body to the length to the detection surface in the evaluation test of the guide body is 0.05 or 0.4.
  • FIG. 21 is a diagram showing the relationship between directivity and the ratio of the length in the extension direction of the guide body to the length to the detection surface in the evaluation test of the guide body
  • FIG. 21 is a diagram showing the relationship between directivity and the ratio of the length in the extension direction of the guide body to the length to the detection surface in the evaluation test of the guide body
  • FIG. 22 is an enlarged sectional view of an essential part of the PM sensor for explaining the clearance ratio d1 / d2 of the element cover in the first embodiment in the evaluation test of the guide body
  • FIG. 23 is a diagram showing the relationship between the clearance ratio d1 / d2 and the output rise time in the evaluation test of the clearance ratio
  • FIG. 24 schematically shows the results of CAE analysis of the gas flow inside the element cover in Embodiment 1
  • FIG. 24 is an enlarged sectional view of an essential part of the PM sensor in the axial direction and the radial direction;
  • FIG. 8 is a view schematically showing a gas flow, comparing an enlarged cross sectional view of the PM sensor in the axial direction and the radial direction
  • 25 is an enlarged sectional view of an essential part in the axial direction of the PM sensor in the second embodiment
  • FIG. 26 is an overall perspective view of a sensor element of the PM sensor in the second embodiment
  • FIG. 27 is an enlarged sectional view of an essential part in the axial direction of the PM sensor in the third embodiment
  • FIG. 28 is an enlarged sectional view of an essential part in the radial direction of the PM sensor in the third embodiment
  • FIG. 29 is an enlarged sectional view of an essential part in the axial direction of the PM sensor in the fourth embodiment
  • FIG. 30 is an enlarged sectional view of an essential part in the radial direction of the PM sensor in the fourth embodiment
  • FIG. 31 is a view schematically showing, in comparison with a modified example of the fourth embodiment, a principal part enlarged cross-sectional view of a PM sensor schematically showing the results of CAE analysis of the gas flow inside the element cover in the fourth embodiment.
  • 32 is an enlarged sectional view of an essential part in the axial direction and the radial direction of a PM sensor according to a fifth embodiment
  • FIG. 33 schematically illustrates an essential part of a PM sensor according to the fifth embodiment, schematically illustrating the assembly angle (mounting direction 0 °) of the PM sensor and the gas flow in the element cover in comparison with the configuration of the fourth embodiment.
  • FIG. 34 is a main part enlarged sectional view of a PM sensor, showing the assembly angle (mounting direction 0 °) of the PM sensor and the pressure distribution in the element cover in comparison with the configuration of the fourth embodiment.
  • FIG. 35 shows an enlarged cross section of a PM sensor according to the fifth embodiment, in which the assembling angle (mounting direction 22.5 °) of the PM sensor and the gas flow in the element cover are compared with the configuration of the fourth embodiment.
  • FIG. 36 shows an enlarged cross section of a PM sensor according to the fifth embodiment, in which the assembly angle (mounting direction 22.5 °) of the PM sensor and the pressure distribution in the element cover are compared with the configuration of the fourth embodiment.
  • FIG. 37 is a view showing the improvement effect (ultra-low flow velocity region) of the assembly angle of the PM sensor and the detection sensitivity in the fifth embodiment in comparison with the configuration of the fourth embodiment
  • 38 is a diagram showing the improvement effect (low flow velocity area to high flow velocity area) of the assembly angle of the PM sensor and the detection sensitivity in the fifth embodiment in comparison with the configuration of the fourth embodiment
  • 39 schematically shows the assembly angle (mounting direction 0 °, 22.5 °) of the PM sensor and the gas flow in the element cover in the fifth embodiment in comparison with the configuration of the fourth embodiment.
  • FIG. 40 is an enlarged sectional view of an essential part of a PM sensor, showing a gas flow (a high flow velocity area) in an element cover of the PM sensor in the fifth embodiment in comparison with the configuration of the fourth embodiment.
  • the sensor device in the present embodiment is a PM sensor S for detecting particulate matter, and is applied to, for example, an exhaust gas purification device of an internal combustion engine E shown in FIG.
  • the PM sensor S includes a sensor element 2 including a detection unit 21, and a housing H in which the sensor element 2 is inserted inside and held so that the detection unit 21 is positioned on the tip side in the axial direction X; And an element cover 1 disposed on the front end side of the housing H.
  • the internal combustion engine E is, for example, an automobile diesel engine or a gasoline engine, and the detection unit 21 of the sensor element 2 detects particulate matter as a specific component contained in the exhaust gas as the gas to be measured.
  • the vertical direction in FIGS. 1 and 3 is the axial direction X
  • the lower end side is the distal end side
  • the upper end side is the proximal end side.
  • the flow direction of waste gas G shown in FIG. 3 be the left-right direction of a figure, let the left of a figure be an upstream, and let a right be a downstream.
  • the element cover 1 has an inner cover 11 disposed so as to cover the tip end side in the axial direction X of the sensor element 2, and an outer cover provided with a space outside the inner cover 11. And 12).
  • the inner cover 11 is provided with an inner side hole 11a and an inner end surface hole 11b through which the gas to be measured flows on the side surface 111 and the end surface 112, respectively.
  • the outer cover 12 is provided with a plurality of outer side holes 12a through which the gas to be measured flows in the side surface 121, and the tip position of the outer side hole 12a is on the tip side of the tip position of the inner cover 11,
  • a first flow passage F1 is formed inside the tip end surface 122, with the direction orthogonal to the axial direction X as the gas flow direction.
  • the inner side hole 11 a opens in a second flow path F 2 provided between the outer side surface of the inner cover 11 and the inner side surface of the outer cover 12. Further, a guide body 13 is provided, which extends incliningly inward of the inner cover 11 from the tip end portion of the inner side surface hole 11a, and as shown in FIG.
  • the detection surface 20 on which the detection unit 21 is disposed is located. The detailed configuration of the element cover 1 will be described later.
  • the PM sensor S coaxially accommodates the sensor element 2 in a cylindrical housing H, and is attached to the tip opening H1 of the housing H so as to cover the tip opening H1 from the tip opening H1
  • the detection part 21 of the sensor element 2 which protrudes is protected.
  • the PM sensor S is, for example, screwed to the exhaust gas pipe wall of the internal combustion engine E shown in FIG. 4 by a screw member H2 provided on the outer periphery of the housing H, and the tip end thereof protrudes into the exhaust gas passage EX.
  • a diesel particulate filter (hereinafter referred to as DPF) 10 is installed in the middle of the exhaust gas passage EX, and the PM sensor S is disposed downstream of the DPF 10 and the exhaust gas after passing through the DPF 10 Particulate matter contained in G (ie, PM shown in the figure) is detected.
  • the particulate matter slipping through the DPF 10 can be detected, and, for example, a part of the abnormality diagnosis system of the DPF 10 can be configured.
  • the flow direction of the exhaust gas G is orthogonal to the axial direction X of the PM sensor S.
  • the sensor element 2 is a laminated element having a laminated structure, and the front surface of the flat rectangular parallelepiped insulating substrate 22 is a detection surface 20, and the detection surface 20 is an electrode 23. , 24 are exposed.
  • the insulating substrate 22 is formed, for example, by firing a laminate in which electrode films to be the electrodes 23 and 24 are alternately disposed between a plurality of insulating sheets to be the insulating substrate 22. At this time, the edge portions of the electrodes 23, 24 embedded at least in part in the insulating base 22 are linearly exposed on the tip end face of the insulating base 22, and alternately from the linear electrodes having different polarities. Constitute a plurality of electrode pairs.
  • Linear electrodes forming a plurality of electrode pairs are arranged in parallel at intervals on the surface excluding the outer peripheral edge on the rectangular tip end surface of the insulating substrate 22 to form the detection portion 21.
  • the detection unit 21 is, for example, a region surrounded by a dotted line in the drawing, and includes a plurality of electrode pairs facing each other with the insulating sheet interposed therebetween and a part of the insulating sheet positioned on the outer peripheral side of the plurality of electrode pairs. Including.
  • the lead portions 23a and 24a connected to the electrode films to be the electrodes 23 and 24 are disposed inside the insulating base 22, and the lead portions 23a and 24a are formed on the surface of the base end side of the insulating base 22.
  • the terminal electrodes 25 and 26 are connected.
  • the detection unit 21 electrostatically collects the particulate matter in the exhaust gas G that reaches the surface of the detection unit 21 by applying a predetermined detection voltage to the electrodes 23 and 24.
  • the detection surface 20 is a region that is slightly larger than the detection unit 21.
  • the entire front end surface of the insulating base 22 including the outer peripheral edge outside the detection unit 21 is used as the detection surface 20. This is because if the exhaust gas G reaches the outer peripheral edge of the detection surface 20, it can easily reach the detection unit 21 along the surface of the detection unit 21, and the region to be the detection surface 20 is appropriately set. be able to.
  • the sensor element 2 may have a rectangular parallelepiped shape in which the tip end surface of the insulating base 22 is substantially square. Also in this case, the entire front end face of the square is the detection surface 20, and the detection unit 21 is disposed in the area excluding the outer peripheral edge portion. More linear electrodes than the sensor element 2 shown in FIG. 5 are arranged in parallel at intervals on the surface of the square detection unit 21 to form a predetermined number of electrode pairs.
  • the insulating substrate 22 can be made of, for example, an insulating ceramic material such as alumina.
  • the electrodes 23 and 24, the lead portions 23a and 24a, and the terminal electrodes 25 and 26 can be made of, for example, a conductive material such as a noble metal.
  • the element cover 1 is in the form of a double container in which the housing H side is open, and includes an inner cover 11 and an outer cover 12 coaxially arranged.
  • the outer cover 12 has a side surface 121 formed of a cylindrical body having a substantially constant diameter, and a tip end surface 122 closing the cylindrical body, and the inner cover 11 is disposed with a space between the outer cover 12 and the inner cover 11. It has the side surface 111 which consists of cylindrical bodies, and the front end surface 112 which closes a cylindrical body.
  • the proximal end portion of the inner cover 11 is an enlarged diameter portion closely contacting the proximal end portion of the outer cover 12 and is integrally fixed to the distal end portion of the housing H.
  • the outer cover 12 is provided with a plurality of outer side surface holes 12 a on the side surface 121 in the vicinity of the distal end surface 122.
  • the outer side surface hole 12a is at a position not overlapping with the inner end surface hole 11b in the axial direction X.
  • the tip end position of the inner end surface hole 11b and the base end position of the outer side surface hole 12a are at the same position.
  • a first flow path F1 is formed inside the distal end surface 122 of the outer cover 12 with the distal end surface 112 of the inner cover 11, and the exhaust gas G flows with the direction orthogonal to the axial direction X as the flow direction.
  • the outer side surface hole 12a is at least the tip end position of the outer side surface hole 12a on the tip end side than the inner tip surface hole 11b which is the tip position of the inner cover 11, and the exhaust gas G may flow through the first flow path F1.
  • the hole center of the outer side surface hole 12a is disposed on the tip side of the inner tip surface hole 11b, the flow rate of the exhaust gas G flowing through the first flow passage F1 increases to the second flow passage F2. Easy to form a gas flow.
  • the outer side surface hole 12a is, for example, a circular through hole and opens in the first flow passage F1.
  • the number and the arrangement of the outer side surface holes 12a are not necessarily limited, but it is desirable that the outer side surface holes 12a be equally arranged over the entire circumference of the side surface 121. For example, they are arranged at equal intervals at eight locations in the circumferential direction. With this configuration, there is no directivity to the gas flow, and not only the assemblability is improved, but also the flow rate of the gas flow formed in the second flow path F2 is stabilized, and the detection accuracy is improved.
  • a plurality of water drainage holes 14 are provided on the distal end surface 122 of the outer cover 12 at an outer peripheral portion not facing the inner distal end surface hole 11 b.
  • the water drain hole 14 is a small hole for discharging the condensed water in the element cover 1 to the outside, and is sufficiently smaller than the outer side surface hole 12 a through which the exhaust gas mainly flows.
  • a second flow path F2 is provided between the outer surface of the inner cover 11 and the inner surface of the outer cover 12.
  • the second flow path F2 has a large clearance portion 31 which is the largest clearance on the outer peripheral side of the tip end surface 112 of the inner cover 11.
  • the small clearance portion 32 which is the minimum clearance is provided, and the large clearance portion 31 and the small clearance portion 32 have a flow path shape connected without steps.
  • the cylindrical body to be the side surface 111 of the inner cover 11 is continuous with the distal end surface 112 and is continuous with the tapered first cylindrical portion 113 whose diameter increases toward the proximal end, and from the first cylindrical portion 113 toward the proximal end And a second cylindrical portion 114 having a substantially constant diameter.
  • the first cylindrical portion 113 is a tapered surface having a constant taper angle, and a large clearance portion 31 is formed between the first cylindrical portion 113 and the outer cover 12 at the end on the tip end side.
  • the second cylindrical portion 114 forms a small clearance 32 with the outer cover 12.
  • the large clearance portion 31 is a portion where the clearance in the direction orthogonal to the axial direction X, that is, the distance between the outer surface of the inner cover 11 and the inner surface of the outer cover 12 is the maximum clearance.
  • the clearance becomes smaller as it goes from the large clearance portion 31 on the distal end side to the proximal end side.
  • the small clearance portion 32 is a portion where the clearance in the direction orthogonal to the axial direction X, that is, the distance between the outer surface of the inner cover 11 and the inner surface of the outer cover 12 is the minimum clearance.
  • the clearance is constant from the distal end side to the proximal end side, and becomes the small clearance portion 32 of the minimum clearance.
  • the inner cover 11 is provided with a plurality of inner side surface holes 11 a at an intermediate portion in the axial direction X of the second cylindrical portion 114 which is the side surface 111 on the base end side.
  • the inner side hole 11a is, for example, a through hole having a long hole shape elongated in the axial direction X, and opens in the second flow path F2.
  • an elongated plate-like guide body 13 is provided integrally with the leading edge.
  • the base end edge portion of the inner side surface hole 11a and the extension end portion of the guide body 13 both have round shapes in which both end corner portions in the width direction are chamfered.
  • the inner end surface hole 11 b is provided at the center of the end surface 112.
  • the inner front end surface hole 11b is, for example, a circular through hole and opens in the first flow passage F1.
  • the inner side holes 11 a are not necessarily limited, it is desirable that the inner side holes 11 a be uniformly arranged on the entire circumference of the side 111.
  • the inner side surface holes 11 a can be arranged at eight positions in the circumferential direction of the side surface 111 at equal intervals.
  • the guide bodies 13 provided in the inner side surface holes 11 a are radially arranged so as to surround the detection surface 20 of the sensor element 2. In this way, there is no directivity to the gas flow, and the assemblability is improved, and the exhaust gas G flowing from the second flow path F2 through the guide body 13 is detected without reducing the speed. It can be led to the surface 20 and the detection accuracy is improved.
  • the exhaust gas G flows from the inner side surface hole 11 a located in the long side direction with respect to the rectangular detection surface 20 and closer to the tip of the guide body 13.
  • the inflow of the exhaust gas G to the detection surface 20 is further increased.
  • FIG. 8 when using the sensor element 2 having the square detection surface 20 (see, for example, FIG. 6), the inner side hole 11a having a large inflow of exhaust gas G regardless of the assembly angle. Since the detection surface 20 is positioned at a substantially constant distance, the mounting directivity can be improved.
  • the guide body 13 is provided integrally with the tip end portion of the inner side surface hole 11 a.
  • the guide body 13 is formed by a cutout portion in which the second cylindrical portion 114 is cut out so as to be integrated with the distal end edge of the inner side surface hole 11a, and the distal end edge of the inner side surface hole 11a is a bending position.
  • the inner cover 11 has an inclined surface 131 extending toward the sensor element 2.
  • the detection surface 20 of the sensor element 2 is on the base end side of the inner side surface hole 11a, and the guide body 13 is a position where the extension line L of the inclined surface 131 and the detection surface 20 intersect.
  • the extension line L is a line obtained by extending the tip of the inclined surface 131 in the extending direction, and may intersect the detection surface 20 at any position.
  • the detection unit 21 be located on the extension line L.
  • the exhaust gas G is directly introduced toward the detection unit 21 located inside the outer peripheral edge of the detection surface 20, so the guide effect can be enhanced and the detection sensitivity can be improved.
  • the position where the extension L intersects the detection surface 20 changes depending on the size of the detection surface 20, the length and position of the guide body 13, the inclination angle, etc., and they are appropriately adjusted to intersect at an arbitrary position. can do.
  • the guide effect is small when the guide body 13 is short, it is desirable to have a sufficient length to obtain the guide effect.
  • the length from the base end of the inner side surface hole 11a, that is, the base end of the inclined surface 131 to the extension end is L1
  • the length to the detection surface 20 is L2
  • the ratio L1 / L2 may be greater than 0.25 (ie, L1 / L2> 0.25). Details of this relationship will be described later.
  • the exhaust gas G flows from the side of the PM sensor S toward the element cover 1 and is introduced into the outer side hole 12 a opened in the side 121 of the outer cover 12. Since the outer side surface hole 12 a is located on the tip side of the tip position of the inner cover 11, in the element cover 1, the exhaust gas G is generated between the tip surface 112 of the inner cover 11 and the tip surface 122 of the outer cover 12.
  • the first flow path F1 flows as it is at a sufficient flow velocity and travels to the outer side surface holes 12a located in the opposite direction (for example, see the dotted arrow in FIG. 9).
  • a part of the exhaust gas G changes its direction toward the base end in the large clearance portion 31 on the downstream side in the flow direction, and the second flow path between the side surface 111 of the inner cover 11 and the side surface 121 of the outer cover 12 It flows into F2 (see, for example, thick arrows in FIG. 9).
  • the exhaust gas G has a small clearance portion 32 while improving the flow velocity by the venturi effect. Head toward the opening inner side hole 11a.
  • the inner cover 11 has a tapered shape in which the first cylindrical portion 113 on the tip end side of the second cylindrical portion 114 forming the small clearance portion 32 reduces in diameter toward the tip end, and the small clearance from the large clearance portion 31 Since the flow passage area is gradually narrowed to the portion 32, the exhaust gas G flows along the side surface 111 of the inner cover 11 and is less likely to cause an eddy flow.
  • the flow velocity of the exhaust gas G is further improved by the effect of suppressing the eddy current, and reaches the inner side surface hole 11a at a sufficient flow velocity. Furthermore, it flows into the inside of the inner cover 11 along the inclined surface 131 of the guide body 13 provided integrally with the inner side surface hole 11a. And, the guide body 13 is provided so that the detection surface 20 of the sensor element 2 is positioned in the extending direction of the inclined surface 131, so the exhaust gas G has a sufficient flow velocity and the tip end of the sensor element 2 The plane detection unit 21 is reached.
  • Such flow of exhaust gas G increases the supply flow rate per unit time to the detection unit 21. Therefore, the time required to detect particulate matter PM is shortened when the DPF 10 breaks down, etc. It can be improved.
  • the exhaust gas G travels to the inner end surface hole 11b opened in the end surface 112 of the inner cover 11 (see, for example, thick arrows in FIG. 3).
  • the exhaust gas G since the exhaust gas G has a sufficient flow velocity, it is in the vicinity of the inner end surface hole 11b. Negative pressure occurs.
  • the exhaust gas G is a side surface of the inner cover 11 in a configuration where the outer side surface hole 12 a is positioned more proximal than the distal end surface 112 of the inner cover 11 for reference. Since the flux does not pass around the portion 111 and below the inner end surface hole 11b, no negative pressure is generated.
  • a hole serving as a gas flow hole is not formed at the end surface 122 of the outer cover 12, particularly at a position facing the inner end surface hole 11b, so the flow direction of the exhaust gas G is orthogonal to the axial direction X. .
  • the inner front end surface hole 11b is not opened in the flow direction of the exhaust gas G, and a flow in the direction to join the exhaust gas G from the inner front end surface hole 11b is formed by the suction effect described above.
  • the exhaust gas G is prevented from flowing directly into the inner cover 11 from the inner front end surface hole 11b.
  • FIG. 11 schematically compares the gas flow in the element cover 1 with and without the guide body 13 based on the analysis result of CAE (that is, Computer aided Engineering) at a low flow rate (for example, 10 m / s). It is shown.
  • CAE Computer aided Engineering
  • the influence of the eddy current inside the inner cover 11 may be suppressed. it can. That is, the exhaust gas G flowing into the outer cover 12 flows in the opposite direction, and a part thereof smoothly flows into the large clearance portion 31 before flowing out from the outer side surface hole 12 a.
  • This flow rises along the second flow passage F2, and the flow velocity increases near the small clearance portion 32 on the proximal end side and flows into the inner side hole 11a. Furthermore, it becomes a jet flow along the inclined surface 131 of the guide body 13 and travels to the sensor element 2.
  • a flow toward the sensor element 2 along the guide body 13 is generated. That is, by being divided by the guide body 13, the flow in the same direction is formed on both sides thereof.
  • the jets along the inclined surface 131 reach the detection surface 20 without being disturbed. Further, a gas flow is formed which is directed to the inner front end surface hole 11b and joined with the exhaust gas G flowing in the first flow path F1 between the both front end surfaces 112 and 122.
  • PM sensor S which has element cover 1 of composition of this form was evaluated about a fall of detection sensitivity by an installation angle at the time of mounting.
  • a PM model gas bench simulating the exhaust gas purification apparatus shown in FIG. 4 is used, PM sensor S is assembled to a pipe through which model gas containing particulate matter flows, and the assembling angle is relative to the central axis The variation of the detection sensitivity when rotating was measured. Further, for comparison, the configuration in which the guide body 13 is not provided in the element cover 1 was similarly evaluated, and the results are shown in comparison with FIG.
  • the sensor element 2 Prior to the evaluation test, the sensor element 2 performs regeneration of the detection unit 21 to heat and remove PM on the surface, and then applies a predetermined collection voltage between the electrodes 23 and 24 to perform electrostatic collection.
  • the rise time of the output i.e., the detection sensitivity
  • the rise time of the output is the time when the particulate matter is collected by electrostatic force and the electrodes 23, 24 are conducted, and the detection current of the detection unit 21 exceeds the preset threshold value. is there.
  • the mounting direction of the element cover 1 is changed by changing the assembly angle of the PM sensor S, the smaller the variation in the rise time (that is, the directivity) due to the mounting direction, the better the detection accuracy.
  • the directivity is represented by the variation (unit: ⁇ %) with respect to the median of the measured rise time.
  • the directivity is large, and when the flow velocity of the exhaust gas G introduced into the element cover 1 (i.e., the piping flow velocity) is 10 m / s, ⁇ 25% is exceeded. There is. When the pipe flow velocity decreases to 5 m / s, the directivity further increases, exceeding ⁇ 40%.
  • the element cover 1 having the guide body 13 the directivity becomes smaller, and the pipe flow velocity is about ⁇ 15% at 10 m / s, or ⁇ 25% at 5 m / s, Reduce significantly. This is presumed to be an increase in the flow rate reaching the detection surface 20 by the effect of the jet flow along the guide body 13 described above, and the effect of improving the detection accuracy by reducing the influence of the mounting direction of the element cover 1 can get.
  • the water resistance of the PM sensor S having the element cover 1 of the configuration of the present embodiment was evaluated using the evaluation device 200 shown in FIG.
  • the evaluation apparatus 200 has a flow path 201 through which air flows, and is configured by disposing a liquid transfer pump 202 for water injection on a pipe wall forming the flow path 201 and disposing a PM sensor S downstream thereof.
  • the PM sensor S is diagonally mounted so that the tip end side faces the upstream side, and when the water droplet W delivered from the liquid feed pump 202 is jetted into the element cover 1 under the following conditions, The maximum amount of water reaching the detection unit 21 was measured.
  • the water amelioration was similarly evaluated, and the results are shown in comparison with FIG. Air flow velocity: 12 m / s Air temperature: 280 ⁇ 20 ° C
  • the element cover 100 of the conventional configuration does not have the first flow path F1, and the tip end face hole 101 of the inner cover 11 and the tip end face hole 102 of the outer cover 12 are coaxially arranged close to each other.
  • the exhaust gas G is configured to travel from the gas flow holes 103 of the side surface 121 of the outer cover 12 to the gas flow holes 104 of the side surface 111 of the inner cover 11 located on the base end side thereof.
  • a small piece of flow straightening member 105 that inclines inward is provided so as to face the side of the sensor element 2.
  • the maximum amount of water coverage when using the element cover 100 of the conventional configuration exceeds 1.7 ⁇ L
  • the maximum amount of water coverage is And a significant reduction of about 88%.
  • only the outer cover 12 has the water draining hole 14 on the outer peripheral portion of the tip end surface 122, and does not have a hole facing the tip end surface hole 11b of the inner cover 11, and air flows directly from the tip end side. do not do. With such a configuration, it is possible to suppress water penetration of the sensor element 2 and to prevent water penetration cracking.
  • FIG. 17 Evaluation of the extension direction of the guide body 13
  • the relative position of the sensor element 2 with respect to the inclined surface 131 of the guide body 13 is changed by changing the axial position.
  • the flow rate of the exhaust gas G introduced to the detection surface 20 was evaluated.
  • the right view of FIG. 17 is a test example 1 of the configuration of the present embodiment at a position where the extension line L of the inclined surface 131 and the detection surface 20 of the sensor element 2 intersect.
  • a configuration in which the side surface slightly proximal to the tip of the sensor element 2 is located on the extension line L of the inclined surface 131 is referred to as a comparative example 1.
  • a configuration in which the tip side surface of the sensor element 2 is positioned on the extension line L of the inclined surface 131 is referred to as a comparative example 2 as shown in the middle view of FIG.
  • the anemometer 4 is disposed inside the element cover 1 at the position of the detection surface 20 instead of the sensor element 2.
  • An evaluation device was prepared, and the flow rate was measured when a constant pipe flow rate (for example, 10 m / s) was given.
  • a constant pipe flow rate for example, 10 m / s
  • the flow velocity measured by the anemometer 4 increases in the order of the comparative examples 1 and 2 as the anemometer 4 increases, but each of about 0.2 m / s and about 0. Both 7 m / s and much less than 1 m / s.
  • Test Example 1 in which the inclined surface 131 extends toward the position of the detection surface 20, the flow velocity is greatly increased to about 8.2 m / s.
  • the exhaust gas G having a sufficient flow rate can be introduced to the detection surface 20 by configuring the detection surface 20 of the sensor element 2 to be located on the extension line L of the inclined surface 131.
  • the left side of FIG. 20 shows the case where the guide body 13 with a length ratio L1 / L2 of 0.05 is provided and gas inflow to the detection surface 20 of the sensor element 2 is recognized, but the directivity is ⁇ 32 It is a little big with%.
  • the gas inflow to the detection surface 20 increases and the directivity decreases to about ⁇ 25%.
  • the directivity hardly changes when L1 / L2 is in the range of 0.05 to 0.25, and when L1 / L2 exceeds 0.25, the directivity is low. It has fallen sharply. Therefore, preferably, the directivity can be reduced by setting the length L1 of the inclined surface 131 of the guide body 13 such that L1 / L2 is in the range exceeding 0.25.
  • the element cover 1 in which the clearance ratio d1 / d2 is 2.45 or more, and the detection sensitivity can be greatly improved.
  • the shape of the second channel F2 gradually narrows the channel area Therefore, the generation of the eddy current is suppressed. That is, in the upper left figure, the exhaust gas G flowing into the outer cover 12 flows in the opposite direction, and part of the exhaust gas G smoothly flows into the large clearance portion 31 before flowing out from the outer side surface hole 12a. This flow rises along the second flow path F2, and the flow velocity increases in the vicinity of the small clearance portion 32 on the proximal end side, and travels from the inner side surface hole 11a to the sensor element 2.
  • the gas flow rate Decelerating is small and the turbulence component due to the vortex is also small. Therefore, in any case, the flow toward the detection surface 20 of the sensor element 2 occurs, and the directivity with respect to the assembly angle decreases.
  • the inner side hole 11a is located on the axial line on the downstream side of the gas flow, the inner side hole 11a is not located on the axial line at an assembly angle of 0 °. That's the case.
  • the distal half side of inner cover 11 is made to be a constant small diameter portion 115, and a tapered shape is formed between it and proximal half portion 116 with a large diameter.
  • a large eddy current is easily formed. That is, in the lower left figure, although the exhaust gas G flowing into the outer cover 12 flows into the outer peripheral space 5 of the tip half portion 116 before flowing out from the outer side hole 12a, it is blocked by the step surface 117 and swirls It is difficult to improve the flow velocity.
  • the gas flow largely changes depending on the position of the inner cover 11 in the rotational direction, as shown in the middle view of the lower portion and the BB cross section shown to the right. That is, at an assembly angle of 0 °, relatively good gas flow is exhibited, but at an assembly angle of 22.5 °, not only the gas flow velocity decelerates, but also the influence of turbulence causes the sensor to The gas flow is away from the detection surface 20 of the element 2. Further, part of the gas leaks from the inner side surface hole 11a to the outer cover 12 side.
  • the gas supply amount at 22.5 ° is approximately 0.5 times and is greatly reduced.
  • Second Embodiment Embodiment 2 of the PM sensor S as a sensor device will be described with reference to FIG. 25 and FIG.
  • the detection unit 21 is provided on the tip end surface of the sensor element 2 in the first embodiment, as shown in FIG. 25, the detection unit 21 may be provided on the side surface of the sensor element 2.
  • the configuration of the PM sensor S other than the sensor element 2 is the same as that of the first embodiment, and thus the description thereof will be omitted, and hereinafter, differences will be mainly described.
  • symbol used in Embodiment 2 or subsequent ones represents the component similar to the thing in already-appeared embodiment, etc., unless shown.
  • the sensor element 2 is a laminated element having a laminated structure, and has a detection unit 21 to which the electrodes 23 and 24 are exposed on one side of the front end side of the rectangular insulating substrate 22.
  • a rather large side surface surrounding the outer periphery of the detection unit 21 is a detection surface 20.
  • the configuration in which the electrodes 23 and 24 are connected to the terminal electrodes 25 and 26 via the lead portions 23a and 24a is the same as that in the above embodiment.
  • the sensor element 2 is arranged such that the side surface having the detection surface 20 provided with the detection unit 21 faces the inner side surface hole 11 a that allows the exhaust gas G to flow into the inner cover 11.
  • the guide body 13 is disposed such that the extension line L of the inclined surface 131 intersects the detection surface 20.
  • the exhaust gas G flowing into the inner cover 11 from the inner side surface hole 11a can easily reach the detection portion 21 located on the detection surface 20 of the opposite side surface without direct diffusion. Therefore, good detection performance can be maintained without lowering the detection sensitivity of the PM sensor S even at low flow rates.
  • the first cylindrical portion 113 of the inner cover 11 may have a shape that gradually reduces in diameter from the large clearance portion 31 on the distal end side to the small clearance portion 32 on the proximal end side, and the whole is necessarily tapered It does not have to be.
  • the tip end portion to be the large clearance portion 31 has a shape having a cylindrical portion 113 a with a substantially constant diameter.
  • the first cylindrical portion 113 excluding the cylindrical portion 113a is formed in a tapered shape having a constant taper angle.
  • the basic configuration of the present embodiment other than that is the same as that of the first embodiment, and the description will be omitted.
  • the flow velocity of the exhaust gas G flowing into the second flow passage F2 and traveling to the small clearance portion 32 can be improved, and the effect of suppressing the vortex flow can be obtained.
  • the clearance d1 of the large clearance portion 31 to be the maximum clearance can be easily set, the second flow path F2 having the predetermined clearance ratio d1 / d2 can be easily formed, and a desired effect can be obtained.
  • the flow rate of the exhaust gas G in the outer cover 12 changes depending on the assembly angle of the element cover 1.
  • the left side of FIG. 28 shows the case where the assembly angle is 0 °, and the outer side surface hole is parallel to the flow direction of the exhaust gas G and on a line passing through the center of the sensor element 2 12a is located.
  • the assembling angles are 11.25 ° and 22.5 °, respectively, and the outer side hole 12a is slightly offset from the axis.
  • the exhaust gas G flows into the inside from the outer side surface hole 12a close to the axis, but there is a portion where the flow velocity decreases in the outer cover 12 as compared with the case where the assembly angle is 0 °. This disturbs the gas flow in the first flow passage F1 and causes a variation due to the assembly angle. Therefore, it is desirable to arrange the outer side surface holes 12a so as to make the gas flow in the first flow path F1 uniform regardless of the assembly angle. Such an arrangement example will be described next.
  • FIG. 29 As shown in FIG. 29, in the present embodiment, the outer cover holes 12a are arranged in two rows in the axial direction X on the side surface 121 close to the tip end surface 122 in the present embodiment. In each row, the outer side surface holes 12a are equally disposed at eight positions in the circumferential direction at equal intervals, and the outer side surface holes 12a belonging to the first row on the distal end side and the outer side surface holes 12a belonging to the second row on the proximal side Are alternately positioned such that the hole centers do not overlap in the axial direction X.
  • the whole of the outer side surface holes 12a in the first row is located between the inner end surface hole 11b and the end surface 122 of the outer cover 12, and the base end position substantially coincides with the end position of the inner end surface hole 11b. As they are located adjacent to each other.
  • the outer side surface holes 12a in the second row are disposed so as to surround the front end portion of the inner cover 11, and the front end positions of the inner side surface holes 11b substantially coincide with each other.
  • the outer side holes 12a are configured to be opened uniformly over the entire circumference, and are less susceptible to the influence of the assembly angle.
  • the outer side surface holes 12a in the first and second rows are formed as circular holes having the same diameter from the tip end side, they may not necessarily have the same shape, and may not be equally disposed. . That is, in the outer side surface holes 12a of the outer cover 12, the hole centers of the outer side surface holes 12a belonging to two adjacent rows in the axial direction may not be located on the same line, but may be located mutually offset.
  • the number of rows of the outer side surface holes 12a, the number of the outer side surface holes 12a of each row, the positional relationship with the inner tip end surface holes 11b, and the like can be changed as appropriate.
  • the tip position of the outer side surface hole 12a in the second row may be on the tip side with respect to the inner tip surface hole 11b
  • the base end position of the outer side surface hole 12a in the first row is based on the inner tip surface hole 11b. It may be an end side.
  • FIG. 30 shows a cross section (that is, a CC cross section) at the position of the outer side hole 12a in the second row of FIG. 29, and in the case where the assembly angle in the left of FIG. , The outer side hole 12a is located.
  • the right side of FIG. 30 shows the case where the assembling angle is 11.25 ° and 22.5 °, respectively, and the outer side hole 12a is slightly offset from the axis, but the outer of the first row not shown is shown.
  • the exhaust gas G can be taken in also from the side holes 12a, and the gas flow rate does not decrease significantly.
  • the shape of the inner cover 11 may be a shape in which the clearance of the second flow path F2 is gradually reduced and the step surface 117 is not provided.
  • the tapered surfaces constituting the first cylindrical portion 113 need not have a constant taper angle, and for example, a shape in which a plurality of tapered surfaces having different taper angles are connected in the axial direction X It can also be done. Also in this case, the same effect can be obtained by connecting the entire first cylindrical portion 113 smoothly and forming a substantially tapered shape in which the diameter decreases from the proximal end side to the distal end side.
  • the effect of improving the flow velocity of the exhaust gas G can be obtained, and the shape of the inner cover 11 or the outer cover 12 forming the second flow path F2 can be appropriately changed within a range that does not significantly affect the gas flow. .
  • the inner cover 11 has a tapered surface
  • a second row of outer side surface holes 12a on the proximal end side may be formed at positions facing the tapered surface (see the left view in FIG. 31).
  • the two rows of outer side surface holes 12a sandwich the inner end surface hole 11b of the inner cover 11, and the first row of outer side surface holes 12a and the second row of outer side surface holes from the tip side. 12a are arranged axially adjacent to each other and circumferentially alternately.
  • the exhaust gas G flowing in from the outer side surface holes 12a constitutes the first cylindrical portion 113. Flow toward the tip side along the tapered surface.
  • This flow flows into the first flow path F1 to increase the gas flow rate in the first flow path F1, thereby generating a negative pressure in the vicinity of the inner front end surface hole 11b, and further, a suction flow effect by the negative pressure Can be improved to form a good gas flow toward the second flow path F2.
  • the outer side surface holes 12 a in the second row face the second cylindrical portion 114 on the proximal side with respect to the first cylindrical portion 113.
  • the formation of the flow toward the first flow path F1 along the tapered surface is sufficiently promoted I will not.
  • forming the second row of outer side surface holes 12a does not provide a sufficient effect of increasing the gas flow rate in the vicinity of the inner front end surface holes 11b.
  • the inner cover 11 has a constant diameter, and the two outer side surface holes 12a are close to each other with the inner end surface hole 11b interposed therebetween. Also in this case, since the flow passing through the outer side of the inner cover 11 is formed together with the flow joining the outer side surface hole 12a to the first flow path F1, the effect of increasing the gas flow rate in the vicinity of the inner tip end surface hole 11b is obtained. descend.
  • the tip position of at least the second row of outer side surface holes 12a is higher than the connection portion between the first cylindrical portion 113 and the second cylindrical portion 114. It should be on the tip side.
  • the hole center of the outer side surface hole 12a is on the tip side of the connection portion between the first cylindrical portion 113 and the second cylindrical portion 114, so that the gas flow along the tapered surface of the first cylindrical portion 113 is more It forms well.
  • Embodiment 5 of the PM sensor S as a sensor device will be described with reference to FIGS.
  • a plurality of outer side surface holes 12a are arranged in two rows in the axial direction X on the side surface 121 close to the tip end surface 122.
  • the 12a are equally disposed at equal intervals at eight locations in the circumferential direction.
  • the outer side surface holes 12a of the first row from the front end side (see the drawing in FIG. 32) and the outer side surface holes 12a of the second row (see the right view of FIG. 32) do not have to have the same shape.
  • the detection sensitivity and the mounting directivity can be further improved by changing the penetration direction of the through hole forming the outer side surface hole 12a.
  • the outer side surface holes 12a in the first row are formed as through holes penetrating the side surface 121 of the outer cover 12 in the direction toward the axial center. That is, eight outer side surface holes 12a are equally arranged, with eight directions extending radially from the axial center as the penetrating direction.
  • the inner side surface holes 11a of the inner cover 11 and the outer side surface holes 12a of the outer cover 12 become such radially formed through holes (hereinafter appropriately referred to as radial holes). ing.
  • the outer side surface holes 12a of the second row are formed as through holes penetrating the side surface 121 of the outer cover 12 in a direction outward from the axial center.
  • the second row of outer side surface holes 12a are respectively paired with one of the first row of outer side surface holes 12a adjacent in the circumferential direction, and the pair of outer side surface holes of the first row is formed.
  • a through hole (hereinafter, referred to as a parallel hole as appropriate) in which the through direction is inclined with respect to the direction toward the axial center is parallel to the through direction of 12 a.
  • T1 of the first row of outer side surface holes 12a and the penetrating direction (T2) of the second row of outer side surface holes 12a is shown in the drawing.
  • sub-flow G2 The flow (hereinafter referred to as sub-flow G2) that flows in from the second row of outer side surface holes 12a and flows to the first flow path F1 merges, as described above, the gas flow rate according to the mounting angle at mounting Fluctuation can be suppressed.
  • the generation sensitivity of the vortex has a large influence on the detection sensitivity, and the improvement effect of the mounting directivity is caused.
  • the effect of the shape of the outer side hole 12a of the second row in this case will be described next.
  • the influence on the gas flow by the arrangement of the guide body 13 in the element cover 1 and the shape of the second flow path F2 was mainly evaluated in the low flow velocity region of about 5 m / s and 10 m / s.
  • the super flow velocity region for example, 3 m / s or less
  • mounting direction the direction of the outer side surface hole 12a corresponding to the mounting angle at the time of mounting
  • one of the two subflows G2 flowing from the second row outer side surface holes 12a is It becomes parallel to the main flow G1 flowing in from the outer side surface holes 12a in the first row. Since this side flow G2 goes to the downstream of the inner cover 11 without colliding with the main flow G1, the flow velocity decrease of the main flow G1 is suppressed, and the generation of the eddy flow on the upstream side is suppressed. Therefore, as shown in the upper part of the right drawing of FIG. 34, the pressure drop is alleviated in the vicinity of the outer side surface hole 12a where the subflow G2 parallel to the main flow G1 is formed. Also, the influence of the pressure drop on the mainstream G1 is reduced. As a result, the generation of negative pressure in the vicinity of the inner front end surface hole 11b is promoted, and the detection sensitivity is improved.
  • the side stream G2 flowing from the second row outer side surface holes 12a is the first row. It becomes parallel to one of the two mainstreams G1 flowing from the outer side hole 12a. Therefore, the reduction in the flow velocity due to the collision with the main flow G1 is avoided, and the generation of the vortex flow is suppressed. Therefore, as shown in the upper and lower parts of the right side of FIG. 36, the pressure drop due to the eddy current loss is reduced, or a pressure drop is observed in the vicinity of the outer side hole 12a where the substream G2 parallel to the main stream G1 is formed. It will not be possible. As a result, a negative pressure is stably generated in the vicinity of the inner front end surface hole 11b, and the detection sensitivity is improved.
  • the flow rate at the time of reaching the detection unit 21 (that is, the reached flow rate shown in the figure) and the assembly angle in an extremely low flow velocity area of 3 m / s or less
  • the ultimate flow rate at an assembly angle of 0 ° is relatively improved. This is mainly because the generation of negative pressure mainly contributes to the detection sensitivity in the very low flow velocity region of 3 m / s or less, and the detection sensitivity is degraded in the very low flow velocity region where the influence of eddy currents due to collision becomes large. It is guessed to be easier. Therefore, the ultimate flow rate at a flow velocity of 1 m / s and 2 m / s is higher at an assembly angle of 22.5 ° than at an assembly angle of 0 °.
  • the outer side surface holes 12a in the second row are formed to be parallel holes, it is possible to suppress a collision and improve detection sensitivity.
  • the improvement effect of this detection sensitivity is seen at both the assembly angle 0 ° and 22.5 °, and at the assembly angle 0 °, the lower the flow velocity, the larger the improvement effect, and the assembly angle 22.5 ° In the case of (1), the higher the flow velocity, the greater the improvement effect.
  • the difference in detection sensitivity between the assembly angles 0 ° and 22.5 ° is reduced, and the mounting directivity is also improved.
  • the second side outer side holes 12a are configured to be parallel holes, thereby reducing the influence of the collision of the side flow G2. be able to.
  • the vortex flow due to the collision of the side flow G2 is suppressed, and two parallel flows join in the vicinity of the inner front end surface hole 11b, thereby the vicinity of the inner front end surface hole 11b.
  • the gas flow rate is increased, and the achievable flow rate can be improved.
  • the ultimate flow rate decreases at an assembly angle of 0 °, while the ultimate flow rate increases at an assembly angle of 22.5 °. That is, the mounting directivity is improved by reducing the difference in detection sensitivity. As described above, with the configuration of the present embodiment, good mounting directivity can be obtained from the very low flow velocity area to the low flow velocity area and further to the high flow velocity area regardless of the flow velocity of the exhaust gas G.
  • the PM sensor S having the stacked sensor element 2 is described as an example, but in the sensor element 2, the print type element in which the electrodes 23 and 24 are printed on the surface to be the detection unit 21 It may be In this case, the electrodes 23 and 24 are printed in a comb shape on the surface of the insulating substrate 22 formed in a flat plate shape, and lead portions 23 a and 24 a similarly printed on the surface of the insulating substrate 22. And the terminal electrodes 25 and 26.
  • PM sensor S as a sensor apparatus was mainly demonstrated in said each embodiment, not only PM sensor S but a sensor apparatus is a gas sensor which detects the specific gas component contained in waste gas G. Good.
  • an exhaust gas sensor such as an oxygen sensor that detects oxygen in the exhaust gas G, an air-fuel ratio sensor that detects an air-fuel ratio, and an NOx sensor that detects NOx can be mentioned.
  • the sensor element 2 used for these gas sensors can have a known configuration, and for example, can have a configuration in which a detection unit 21 having an electrode for detection is provided on the tip side of a cup-type or stacked-type element. .
  • the element cover 1 can protect the outside by inserting and holding the inside of the housing H so that the detection unit 21 is on the tip side in the axial direction X. Then, the exhaust gas G introduced inside the element cover 1 can be guided from the second flow path F1 to the second flow path F2, and can be guided to the detection surface 20 through the guide body 13, and the detection portion of the sensor element 2 21 to improve the responsiveness of the output.
  • the exhaust gas purification performance can be improved by grasping
  • the present disclosure is not limited to the above embodiments, and can be applied to various embodiments without departing from the scope of the invention.
  • the internal combustion engine is not limited to an automobile engine, and exhaust gases from various devices may be measured gas. it can.
  • the gas to be measured is not limited to the exhaust gas from the internal combustion engine, and can be applied to a sensor device for detecting a specific component contained in various gases.

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Abstract

La présente invention concerne un dispositif de type capteur (S) qui comprend un couvercle d'élément (1) disposé sur le côté extrémité distale d'un boîtier (H) qui renferme un élément capteur (2). Un couvercle externe (12) est pourvu d'une pluralité de trous de surfaces latérales externes (12a) dans les surfaces latérales (121), la position d'extrémité distale des trous de surfaces latérales externes (12) est située plus près de l'extrémité distale que la position d'extrémité distale d'un couvercle interne (11), et un premier canal (F1) dans une direction d'écoulement de gaz orthogonale à une direction axiale (X) est formé sur le côté interne d'une surface d'extrémité distale (122). Un trou de surface latérale interne (11a) du couvercle interne (11) s'ouvre dans un second canal (F2) disposé entre la surface latérale du couvercle interne (11) et la surface latérale du couvercle externe (12). Une surface de détection (20) de l'élément capteur (2) est située sur une ligne étendue (L) dans la direction d'extension d'un corps de guidage (13) qui s'étend à partir de la partie bord d'extrémité distale du trou de surface latérale interne (11a) vers le côté interne du couvercle interne (11) tout en étant incliné.
PCT/JP2018/043091 2017-11-29 2018-11-22 Dispositif de type capteur WO2019107257A1 (fr)

Priority Applications (3)

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CN201880076886.4A CN111417849B (zh) 2017-11-29 2018-11-22 传感器装置
DE112018006083.7T DE112018006083T5 (de) 2017-11-29 2018-11-22 Sensorvorrichtung
US16/885,648 US11422069B2 (en) 2017-11-29 2020-05-28 Sensor device

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JP2017229646 2017-11-29
JP2017-229646 2017-11-29
JP2018-180508 2018-09-26
JP2018180508A JP6984572B2 (ja) 2017-11-29 2018-09-26 センサ装置

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3691242B2 (ja) * 1998-02-26 2005-09-07 日本特殊陶業株式会社 ガスセンサ
JP3829026B2 (ja) * 1999-04-19 2006-10-04 日本碍子株式会社 ガスセンサ
JP4131242B2 (ja) * 2003-01-20 2008-08-13 株式会社デンソー ガスセンサ
US20150192509A1 (en) * 2012-06-27 2015-07-09 Robert Bosch Gmbh Gas sensor
JP2016003927A (ja) * 2014-06-16 2016-01-12 株式会社日本自動車部品総合研究所 粒子状物質検出センサ
JP2017058358A (ja) * 2015-09-17 2017-03-23 株式会社デンソー ガスセンサ
WO2017097491A1 (fr) * 2015-12-07 2017-06-15 Robert Bosch Gmbh Capteur de gaz

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3691242B2 (ja) * 1998-02-26 2005-09-07 日本特殊陶業株式会社 ガスセンサ
JP3829026B2 (ja) * 1999-04-19 2006-10-04 日本碍子株式会社 ガスセンサ
JP4131242B2 (ja) * 2003-01-20 2008-08-13 株式会社デンソー ガスセンサ
US20150192509A1 (en) * 2012-06-27 2015-07-09 Robert Bosch Gmbh Gas sensor
JP2016003927A (ja) * 2014-06-16 2016-01-12 株式会社日本自動車部品総合研究所 粒子状物質検出センサ
JP2017058358A (ja) * 2015-09-17 2017-03-23 株式会社デンソー ガスセンサ
WO2017097491A1 (fr) * 2015-12-07 2017-06-15 Robert Bosch Gmbh Capteur de gaz

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