JP2012068148A - Particulate material detection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a particulate material detection sensor provided with a cover body capable of effectively collecting PM on a detector.SOLUTION: A cover body 20 includes: a measurement object gas inlet hole Hfor introducing a measurement object gas to a detector 11; a side face outlet hole Hfor deriving the gas in the side direction; and an underside outlet hole Hfor deriving the gas in the downward direction. The measurement object gas inlet hole H, the side face outlet hole H, and the underside outlet hole Hare regulated in a prescribed range, and at least a distance Lfrom the base end of the cover body 20 to the opening position of the measurement object gas inlet hole Hand a distance Lfrom the base end of the cover body 20 to the front end of the cover body 20 are regulated. The flow of the measurement object gas colliding against the detector 11 is separated in horizontal and vertical directions and the flow rate of the measurement object gas introduced into the cover body 20 is suppressed by an eddy current generated upstream of the detector 11 in the cover body 20, while deriving the measurement object gas from the side face outlet hole Hand the underside outlet hole Hto the outside of the cover body 20.

Description

  The present invention relates to an electric resistance type particulate matter detection sensor that is suitably used in, for example, an exhaust purification system of an internal combustion engine for a vehicle and detects the amount of particulate matter present in exhaust gas.

  Collects environmental pollutants contained in exhaust gas, especially particulate matter (Particulate Matter; hereinafter referred to as PM as appropriate) mainly composed of soot particles and soluble organic components (SOF) in automobile diesel engines, etc. In order to do this, a diesel particulate filter (hereinafter referred to as DPF as appropriate) is installed in the exhaust passage. The DPF is made of porous ceramics having excellent heat resistance, and traps PM by passing exhaust gas through a partition wall having a large number of pores.

If the amount of collected PM exceeds the allowable amount, DPF may cause clogging and increase pressure loss or increase of PM slipping. It is recovering.
The regeneration timing of the DPF is generally determined by utilizing the fact that the differential pressure across the front increases as the amount of collected PM increases. For this reason, a differential pressure sensor for detecting the pressure difference between the upstream and downstream of the DPF is installed. The regeneration process is performed by introducing high-temperature combustion exhaust gas into the DPF by heater heating or post-injection, and burning off PM.

On the other hand, various types of particulate matter detection sensors that can directly detect PM in combustion exhaust (hereinafter referred to as PM sensors as appropriate) have been proposed. This PM sensor is installed downstream of the DPF, for example, and the amount of PM passing through the DPF is measured. In an on-board diagnosis (OBD), monitoring of the operating state of the DPF, for example, abnormalities such as cracks and breakage It can be used for detection.
Alternatively, it is also considered to install upstream of the DPF, measure the amount of PM flowing into the DPF, and use it to determine the regeneration time instead of the differential pressure sensor.

As a basic configuration of such a PM sensor, Patent Document 1 discloses an electric resistance type in which a pair of conductive electrodes are formed on the surface of an insulating substrate and a heating element is formed on the back surface or inside of the substrate. A smoke sensor is disclosed. This sensor utilizes the fact that smoke (fine carbon) has electrical conductivity, and detects a change in resistance value caused by the deposition of smoke between electrodes serving as a detection unit.
The heating element heats the detection unit to a desired temperature (for example, 400 ° C. to 600 ° C.), measures the interelectrode resistance, burns off the attached smoke, and recovers the detection capability.
In addition, in this type of PM sensor, the front and back surfaces of the substrate excluding the detection unit are covered with an airtight insulating material in order to prevent a malfunction due to the formation of a conductive path due to PM deposition on the surface other than the detection unit. Insulation protection.
Furthermore, in this kind of PM sensor, the detection part is covered with the cylindrical cover body, and it is protected from damage to the sensor element due to water or flying stones.

  Conventionally, gas sensors that detect specific components in a gas to be measured, such as an oxygen sensor, a NOx sensor, an air-fuel ratio sensor, and the like, as disclosed in Patent Document 2, are used to protect the sensor element from being exposed to water and to cover the inside and outside of the cover. Various structures for improving the response of the gas sensor by improving the exchange of the gas to be measured have been studied.

However, in a gas sensor that detects the concentration of a specific component in a gas to be measured, such as an oxygen sensor, the measurement target is a gas. Therefore, the gas to be measured is quickly exchanged inside and outside the cover to improve responsiveness. However, in the PM sensor, the PM contained in the gas to be measured is deposited on the detection unit of the sensor element at an early stage, and the PM once deposited on the detection unit is removed from the detection unit. It is important not to leave them apart.
For this reason, in the same manner as in the conventional gas sensor disclosed in Patent Document 2, if the cover body in which the flow path direction is changed in a complicated manner is used in order to improve the response while protecting from moisture, the detection unit is reached. There is a possibility that PM adheres to the cover body and PM cannot be deposited on the detection part at an early stage.
However, the cover body that can reliably collect and deposit PM in the detection unit while protecting the detection element of the PM sensor that detects PM in the gas to be measured has not been sufficiently studied.

  Accordingly, in view of such circumstances, the present invention is a particulate matter detection sensor for detecting PM contained in a gas to be measured, and is capable of efficiently collecting PM in a detection unit while protecting the detection element. An object of the present invention is to provide a particulate matter detection sensor provided with a cover body that can be used.

In the first invention, the front end of the detection element formed in a substantially flat plate shape having a predetermined lateral width, length, and thickness is placed in the measured gas flow path, and the predetermined lateral width provided on the front end side of the detection element. And a particulate matter detection sensor for detecting particulate matter contained in the gas to be measured by detecting a physical quantity that varies depending on the amount of particulate matter deposited on the detection unit having a vertical width,
The detection unit is made to face the upstream side of the gas flow path to be measured, and a substantially cylindrical cover body having a predetermined inner diameter and length covering the tip of the detection element including the detection unit is provided,
The cover body is at least
While facing the detection unit, it opens toward the upstream side of the gas to be measured and introduces the gas to be measured into the cover body, or a circular gas to be measured introduction hole,
A rectangle that opens toward both sides of the detection unit and leads the measurement gas introduced into the cover body in a side surface direction, or a circular side surface lead-out hole;
A rectangular opening for opening the gas to be measured introduced into the cover body to the lower side of the distal end, or a circular lower surface outlet hole, which opens toward the lower side of the distal end of the detection unit,
The opening width and opening length of each of the measured gas introduction hole, the side surface outlet hole, and the lower surface outlet hole, or the opening diameter is defined in a range from a predetermined lower limit value to an upper limit value, and
Defining at least the distance from the base end of the cover body to the opening position of the gas inlet hole to be measured and the distance from the opening position of the gas inlet hole to be measured to the tip of the cover body;
The flow of the gas to be measured that collides with the detection unit is distributed to the top, bottom, left, and right, and is generated outside the cover body from the side surface extraction hole and the bottom surface extraction hole, and is generated upstream of the detection unit in the cover body. The flow velocity of the gas to be measured introduced into the cover body is suppressed by the eddy current that flows (claim 1).

  According to the first invention, since the flow velocity of the gas to be measured introduced into the cover body is suppressed by the generation of the eddy current, when the gas to be measured collides with the detection unit, After the contained particulate matter is adsorbed and deposited on the surface of the detection unit, it becomes difficult to desorb by the subsequent flow of the gas to be measured. For this reason, the amount of particulate matter deposited on the detection unit can be increased.

  In the second invention, the upper limit value of the opening width of the measured gas introduction hole is smaller than the width defined by the intersection with the straight line projected from the side edge of the detection element onto the cover body. The lower limit value of the opening width of the gas introduction hole is larger than ½ of the width defined by the intersection with the straight line projected from the side edge of the detection element onto the cover (claim 2).

If the opening lateral width of the measured gas introduction hole is formed within the range of the second invention, a flow is formed in which the measured gas introduced into the cover body is distributed to the left and right after colliding with the detection element. In addition, a vortex flowing toward the upstream side with respect to the detection element is generated in a part of the detection element, and the flow rate of the measurement gas introduced into the cover body from the measurement gas introduction hole is suppressed, and the detection unit The amount of particulate matter deposited on the substrate can be increased.
On the other hand, outside the scope of the second invention, when the opening width of the measurement gas introduction hole is equal to or greater than the width of the detection element, the flow rate of the measurement gas introduced into the cover body is not suppressed, As a flow is formed directly from the measurement gas introduction hole toward the side surface outlet hole, and the detection element is not covered with the cover body, there is a possibility that the particulate matter is difficult to deposit on the detection unit.
Further, outside the scope of the second invention, the opening width of the gas introduction hole to be measured is not more than ½ of the width defined by the intersection with the straight line projected from the side edge of the detection element onto the cover body. In some cases, the amount of gas to be measured introduced into the cover body is excessively suppressed, and it may be difficult for particulate matter to accumulate on the detection unit.

  In the third aspect of the invention, the upper limit value of the opening vertical width of the measurement gas introduction hole is smaller than the vertical width of the detection unit, and the lower limit value of the opening vertical width of the measurement gas introduction hole is the vertical value of the detection unit. It is larger than 1/2 of the width (claim 3).

If the opening length of the gas to be measured introduction hole is formed within the range of the third invention, the gas to be measured introduced into the cover body is flowed up and down after colliding with the detection element. Is formed, a vortex flowing toward the upstream side with respect to the detection element is generated in part, and the flow rate of the measurement gas introduced into the cover body from the measurement gas introduction hole is suppressed, The amount of particulate matter deposited on the detection unit can be increased.
On the other hand, if it is outside the scope of the third invention and the opening vertical width of the measurement gas introduction hole is equal to or greater than the vertical width of the detection section, the flow velocity of the measurement gas introduced into the cover body is sufficiently suppressed. Instead, a flow is formed directly from the measured gas introduction hole to the lower surface outlet hole, and the particulate matter is less likely to be deposited on the detection portion, as in the case where the detection element is not covered by the cover body. There is a fear.
Further, if it is outside the scope of the third invention and the opening vertical width of the measurement gas introduction hole is ½ or less of the vertical width of the detection section, the amount of the measurement gas introduced into the cover body May be excessively suppressed, and particulate matter may not easily accumulate on the detection unit.

  In the fourth invention, the upper limit value of the lateral width of the side surface outlet hole is smaller than the lateral width defined by the intersection with the straight line projected from the side edge of the detection element on the cover body, The lower limit of the lateral width of the opening is larger than ½ of the lateral width defined by the intersection with the straight line obtained by projecting the side edge of the detection element onto the cover body.

If the lateral width of the side lead-out hole is formed within the range of the fourth invention, the object to be measured that flows outside the cover body along the outer peripheral surface of the cover body after colliding with the front surface of the cover body The flow velocity of the gas to be measured led out from the side lead-out hole is adjusted to a range in which a vortex can be generated on the upstream side of the detection unit by the gas drawing force, and is introduced into the cover body from the gas to be measured introduction hole. The flow rate of the gas to be measured can be suppressed, and the amount of particulate matter deposited on the detection unit can be increased.
On the other hand, outside the scope of the fourth invention, when the lateral width of the side lead-out hole is equal to or greater than the lateral width defined by the intersection with the straight line projected on the cover body at the side edge of the detection element, As in the case where a flow is formed directly from the measurement gas introduction hole toward the side lead-out hole, and the detection element is not covered by the cover body, there is a possibility that the particulate matter is difficult to deposit on the detection unit. is there.
Further, outside the scope of the fourth invention, the lower limit of the opening lateral width of the side surface lead-out hole is not more than ½ of the lateral width defined by the intersection with the straight line projected from the side edge of the detection element onto the cover body. In some cases, the measurement gas once introduced into the cover body is difficult to be led out of the cover body, and as a result, the measurement gas introduced into the cover body from the measurement gas introduction hole There is a possibility that the flow rate decreases and it becomes difficult to deposit particulate matter on the detection unit.

  In the fifth invention, the lower limit value of the opening vertical width of the side surface outlet hole is larger than ½ of the vertical width of the detection section.

If the opening vertical width of the side surface lead-out hole is formed within the range of the fifth invention, a flow in which the gas to be measured introduced into the cover body is distributed to the left and right after colliding with the detection element is formed, A vortex flowing toward the upstream side with respect to the detection element is generated in a part of the detection element, and the flow rate of the measurement gas introduced into the cover body from the measurement gas introduction hole is suppressed to the detection unit. The amount of particulate matter deposited can be increased.
On the other hand, when it is outside the scope of the fifth invention and the opening width of the side surface outlet hole is ½ or less of the vertical width of the detection portion, the measurement gas introduced into the cover body cannot be derived. Since it is excessively suppressed and stays in the cover body, the introduction of the gas to be measured is excessively suppressed, and it may be difficult to deposit particulate matter on the detection unit.

  In the sixth invention, the upper limit value of the opening diameter of the lower surface lead-out hole is equal to or smaller than the inner diameter of the cover body, and the lower limit value of the opening diameter of the lower surface lead-out hole projects the side edge of the detection element onto the cover body. It is larger than 1/2 of the lateral width defined by the intersection with the straight line.

If the opening diameter of the lower surface lead-out hole is formed within the range of the sixth invention, the lower surface lead-out is performed after the gas to be measured introduced into the cover body from the measured gas introduction hole collides with the detection unit. When derived from the hole, the flow velocity of the measurement gas derived from the lower surface extraction hole can generate a vortex on the upstream side of the detection unit due to the drawing force of the measurement gas flowing around the lower end of the cover body. The amount of particulate matter deposited on the detection unit can be increased by adjusting the flow rate and suppressing the flow rate of the measurement gas introduced into the cover body from the measurement gas introduction hole.
On the other hand, outside the range of the sixth invention, the opening diameter of the lower surface lead-out hole is ½ or less of the lateral width defined by the intersection with the straight line projected on the side edge of the detection element on the cover body. In this case, the gas to be measured is difficult to be led out from the lower surface lead-out hole and stays in the cover body, so that the introduction of the gas to be assumed is excessively suppressed and the particulate matter may not be easily deposited on the detection unit. is there.

  Further, as in the seventh invention, a plurality of the side surface lead-out holes may be formed side by side with respect to the axial direction of the cover body.

  Further, as in the eighth invention, the side surface lead-out hole may be formed in a long hole shape extending in the axial direction of the cover body.

  According to the seventh invention or the eighth invention, when the gas to be measured introduced into the cover body collides with the detection unit and then is distributed vertically and horizontally, the flow toward the side lead-out hole is generated. The flow is relatively increased, and the flow toward the lower surface outlet hole is relatively suppressed. As a result, it is expected that the amount of particulate matter deposited on the detection unit can be increased by relatively increasing the upward vortex flow of the detection unit.

  In the ninth invention, the inner diameter of the cover body is not more than twice the lateral width of the detection element.

According to the ninth aspect of the present invention, by suppressing the flow velocity in the cover body, the detachment of the particulate matter deposited on the detection unit is made difficult to occur, and the responsiveness is increased by increasing the deposition amount on the detection unit. A good particulate matter detection sensor can be realized.
On the other hand, when the inner diameter of the cover body is out of the range of the eighth invention and exceeds twice the lateral width of the detection element, it approaches the flow velocity when the cover body is not provided. There is a risk that the particulate matter will be difficult to deposit.

  In a tenth aspect of the invention, a predetermined eddy current formation distance is provided from the base end of the cover body to the opening position of the measurement gas introduction hole.

  In an eleventh aspect of the invention, a predetermined eddy current forming distance is provided from the opening position of the measurement target gas introduction hole to the tip of the cover body.

  According to the tenth invention or the eleventh invention, by suppressing the flow rate in the cover body, it is difficult for the particulate matter deposited on the detection unit to be detached, and the deposition on the detection unit is performed. A responsive particulate matter detection sensor with an increased amount can be realized.

More specifically, as in the twelfth aspect, when the horizontal width of the detection section is 2 mm or more and 10 mm or less and the vertical width is 2 mm or more and 10 mm or less, the opening horizontal width of the measured gas introduction hole is 1 mm or more and 10 mm or less. (Claim 12).

  As in the thirteenth invention, when the horizontal width of the detection unit is 2 mm or more and 10 mm or less and the vertical width is 2 mm or more and 10 mm or less, the opening vertical width of the measured gas introduction hole is desirably 1 mm or more and 10 mm or less. (Claim 13).

  As in the fourteenth aspect, when the lateral width of the detection element is 10 mm, it is desirable that the lateral lateral opening opening has an opening lateral width of 5 mm to 10 mm.

  As in the fifteenth aspect of the invention, when the lateral width of the side lead-out hole is 10 mm, the vertical width of the side lead-out hole is preferably 5 mm or more and 10 mm or less.

  As in the sixteenth aspect of the invention, when the width of the detection element is 10 mm, it is desirable that the opening diameter of the lower surface outlet hole is 5 mm or more.

  As in the seventeenth aspect of the invention, it is desirable that the distance from the base end of the cover body to the opening position of the measured gas introduction hole is 10 mm or more and 30 mm or less.

  As in the eighteenth aspect of the invention, it is desirable that the distance from the opening position of the measured gas introduction hole to the tip of the cover body is 5 mm or more and 15 mm or less.

  According to the twelfth to eighteenth inventions, by suppressing the flow velocity in the cover body, it is difficult for the particulate matter deposited on the detection unit to be detached, and the amount deposited on the detection unit is increased. A responsive particulate matter detection sensor can be realized.

  In a nineteenth aspect, the physical quantity is any one of a resistance value, capacitance, impedance, oxidation-reduction potential, or a combination of physical quantities selected from these, which varies depending on the amount of particulate matter deposited on the detection unit. (Claim 19).

  In any of the nineteenth inventions, the physical quantity obtained as a result can be reduced because the particulate matter deposited on the detection part is less likely to be detached by suppressing the flow rate in the cover body. Becomes stable and the reliability as a particulate matter detection sensor is increased.

BRIEF DESCRIPTION OF THE DRAWINGS The outline | summary of the particulate-material detection apparatus in the 1st Embodiment of this invention is shown, (a) is a longitudinal cross-sectional view, (b) The half cross-sectional view along 10-10 in this figure (a), (c). (A) is a cross-sectional view along CC in the figure (a), (d) is a bottom view in DD in the figure (a). FIG. 3 is a developed perspective view illustrating an example of a detection element used in the particulate matter detection device according to the first embodiment of the present invention. The cross-sectional view for demonstrating the effect of the particulate matter detection apparatus in the 1st Embodiment of this invention. The longitudinal cross-sectional view for demonstrating the effect of the particulate matter detection apparatus in the 1st Embodiment of this invention. It is explanatory drawing for demonstrating the structure which cannot exhibit the effect of this invention, Comprising: (a) is a cross-sectional view which concerns on the comparative example 1, (b) is a cross-sectional view which concerns on the comparative example 2. FIG. It is explanatory drawing for demonstrating the structure which cannot exhibit the effect of this invention, Comprising: (a) is a longitudinal cross-sectional view concerning the comparative example 3, (b) is a longitudinal cross-sectional view concerning the comparative example 4. FIG. It is explanatory drawing for demonstrating the structure which cannot exhibit the effect of this invention, Comprising: (a) is a cross-sectional view concerning the comparative example 5, (b) is a cross-sectional view concerning the comparative example 6. FIG. It is explanatory drawing for demonstrating the structure which cannot demonstrate the effect of this invention, Comprising: (a) is a cross-sectional view which concerns on the comparative example 7, (b) is a longitudinal cross-sectional view which concerns on the comparative example 8. FIG. It is explanatory drawing for demonstrating the structure which cannot exhibit the effect of this invention, Comprising: (a) is a longitudinal cross-sectional view which concerns on the comparative example 9, (b) is a longitudinal cross-sectional view which concerns on the comparative example 10. FIG. The effect of this invention is shown, (a) is drawing substitute photograph which shows the collection state of PM in a detection part, (b) is the collection state of PM when the cover body shown as a comparative example is not provided. Drawing substitute photo shown. The perspective view which shows the modification of the cover body which is the principal part of this invention to (a)-(f). The modification in the 1st Embodiment of this invention is shown, (a) is a cross-sectional view concerning Example 2, (b) is a longitudinal cross-sectional view concerning Example 3. FIG. The cross-sectional view which concerns on Example 4 of this invention. The effect of this invention is shown, (a) is the characteristic view which concerns on introduction hole opening lateral width, (b) is the characteristic view which concerns on introduction hole opening vertical width. The effect figure of this invention is shown, (a) is the characteristic view which concerns on the side surface lead-out hole opening width, (b) is the characteristic view which concerns on the side surface lead-out hole opening width. The effect of this invention is shown, (a) is a characteristic view which concerns on a lower surface outlet hole opening diameter, (b) is a characteristic view which concerns on a pressure adjustment hole.

  With reference to FIG. 1, the outline | summary of the particulate matter detection sensor 1 in the 1st Embodiment of this invention is demonstrated. The particulate matter detection sensor 1 is provided in the exhaust passage of the internal combustion engine, detects particulate matter (PM) contained in the gas to be measured, and is used for combustion control of the internal combustion engine, DPF failure diagnosis, and the like. Is.

The particulate matter detection sensor 1 is fixed to a measurement gas flow path by a housing 40 via an insulator 30, and has a detection element 10 disposed with the detection unit 11 facing the upstream side of the measurement gas. It is a main part, and is constituted by a substantially cylindrical cover body 20 that is fixed to the housing 40 and covers the tip of the detection element 10.
The cover body 20 is formed in a substantially cylindrical shape so as to cover the outer periphery of the detection element 10, and a flange portion 21 that protrudes toward the outer diameter direction is provided on the proximal end side, and is provided at the distal end of the housing 40. It is fixed by caulking by the caulking portion 41.
In the peripheral wall portion 22 of the cover body 20, an introduction hole H that opens toward the upstream side of the gas to be measured at a position facing the detection portion 11 of the detection element 10 and introduces the gas to be measured inside the cover body 20. ₁ and at positions opposite to both side surfaces of the detection element 10, perpendicular to the flow direction of the gas to be measured, open toward both side surfaces of the cover body 20, and into the cover body 20 in the side surface direction of the detection element 10. The side surface outlet hole H _{2 for} leading the introduced measurement gas and the pressure of the measurement gas that opens toward the downstream side of the measurement gas and that is introduced into the cover body 20 and exists on the back side of the detection element 10 are balanced. And a pressure adjusting hole H ₄ for introducing or deriving the gas to be measured, and the bottom 22 of the cover body 20 opens toward the longitudinal axis of the detection element 10. Lower the tip of the introduced gas to be measured Bottom out hole H ₃ which headed derived is bored.
Note that the inner diameter φD ₂₀ of the cover body 20 is formed to be not more than twice the lateral width W ₁₀ of the detection element 10.

In the present invention, the measured gas introduction hole H ₁ , the side surface outlet hole H _2, and the lower surface outlet hole H ₃ are each of the opening lateral width W ₁ , W ₂ , and / or the opening diameter W ₃ , or the opening longitudinal width T. ₁ , T ₂ is a predetermined opening width upper limit value W _1HL , W _2HL and / or opening diameter upper limit value W _3HL , opening width lower limit value W _1LL , W _2LL , and / or opening diameter lower limit value W _{3LL and} opening length The upper limit value T _1HL , the opening vertical width lower limit value T _1LL , and T _2LL are formed so as to be within a range from a predetermined lower limit value to an upper limit value, and at least from the base end of the cover body 20. and the distance L to the open position of the measurement gas introducing hole H _1, a distance L ₁ from the open position of the measurement gas introducing hole to the tip of the cover member to define a measurement gas impinging on the detection unit 11 The flow is divided into up, down, left and right sides While derived from the outlet hole H ₂ and the lower surface outlet hole H ₃ to the outside of the cover body 20, the flow rate of the measurement gas introduced into the upstream-side cover body 20 by a vortex generated in the detecting section 11 in the cover body 20 This is characterized in that the particulate matter deposited on the detection unit 11 is prevented from being detached.

Here, an example of a specific configuration of the detection element 10 used in the particulate matter detection sensor 1 of the present invention will be described with reference to FIG.
In the present embodiment, the detecting element 10 has a substantially flat plate shape the size of the portion exposed to the cover body 20 has a predetermined width W ₁₀ and the length L ₁₀ and the thickness t _10, the distal end The detector 11 is provided, and the detector 11 is placed in the measured gas flow path so as to face the upstream side of the measured gas flow path.
The resistance value of the conduction path formed by the PM deposited between the pair of electrodes is detected as a physical quantity that varies depending on the amount of PM deposited on the detection unit 11 of the detection element 10.
The detection unit 11 includes an insulating heat-resistant substrate 100 and a pair of detection electrodes 110 and a detection electrode 120 provided on the surface of the insulating heat-resistant substrate 100 exposed to the gas to be measured at a predetermined distance. Yes.

In this embodiment, the detection electrode 110 and the detection electrode 120 are connected to lead portions 111 and 121 that are connected to a resistance measurement unit (not shown) provided outside, and the plurality of detection electrodes 110 and the detection electrodes 120 are connected. Are formed in a comb shape so as to alternately face each other.
Furthermore, in order to ensure the insulation of the lead portions 111 and 121, an insulating heat-resistant protective layer is formed using an insulating heat-resistant material so as to cover the surface of the insulating heat-resistant substrate 100 excluding the detection portion 11 and the lead portions 111 and 121. 103 is formed.
A pair which is laminated on the back side of the insulating heat-resistant substrate 100 and is sandwiched between the insulating heat-resistant substrates 101 and 102 and generates heat when energized, and connects the heater 130 and an energization control device (not shown) provided outside. Heater lead portions 131 and 132 are formed.
The insulative heat resistant substrates 100, 101, 102 are formed in a flat plate shape by using an electrically insulative heat resistant material such as alumina by a known method such as a doctor blade method, a press molding method, CIP, or HIP. Depending on the thickness of the insulating heat-resistant substrate 100, the insulating substrate 101 provided in the middle may be discarded.
The detection electrodes 110 and 120, the lead portions 111 and 121, the heater 130, and the heater lead portions 131 and 132 are formed by a known method such as thick film printing, plating, vapor deposition, and the like, and these are integrally laminated and baked to detect elements. 10 is formed.
By measuring the electrical resistance between the detection electrodes 110 and 120 that varies depending on the amount of conductive PM deposited between the pair of detection electrodes 110 and 120, the PM contained in the gas to be measured can be detected.

In the particulate matter detection sensor 1 of the present invention, the position and size of the introduction hole H ₁ , the lead-out holes H ₂ and H ₃ , and the pressure adjustment hole H ₄ formed in the cover body 20 are defined, and the detection unit 11 is characterized by maximizing the amount of PM deposited on the sensor 11, and the detection element 10 used for this is provided with the detection part 11 of the detection element 10 formed in a substantially flat plate shape in the gas to be measured. If a physical quantity that changes depending on the amount of PM collected by the detection unit 11 is detected, a resistance value that changes according to the amount of PM deposited on the detection unit 11 as in this embodiment is measured as the physical quantity. However, the detection unit 11 may measure the capacitance that varies depending on the amount of PM deposited on the detection unit 11 or the impedance that varies depending on the amount of PM deposited on the detection unit 11. Accumulated Any of redox potentials generated when PM is oxidized and removed, or a combination of those that measure physical quantities selected from these may be used.
Further, not only the pair of detection electrodes 110 and 120 are formed in a comb-like shape and the resistance value is measured as in the present embodiment, but a porous electrode is formed in the detection portion, and resistance caused by PM deposition It may be one that detects a change in value.

Width W ₁ horizontal measurement gas introducing hole H ₁ is less than 1/2 of the predetermined introduction of width W ₁₀ that is defined by the intersection of the projection of the side edges of the detection element 10 to the cover body 20 linearly The hole width lower limit W _1LL is set to be equal to or greater than a predetermined introduction hole width upper limit W _1HL equal to or less than the width W ₁₀ defined by the intersection with the straight line projected on the cover body 20 at the side edge of the detection element 10. Has been.
Longitudinal width _{T 1} of the axial direction of the measuring gas introducing hole _{H 1} is set to 1/2 or more than a predetermined inlet hole vertical width lower limit _{T 1LL} of longitudinal width _{T 11} of the detection unit 11, the detector 11 It is set to a predetermined introduction hole vertical width upper limit value T _1HL or less which is a vertical width T ₁₁ or less.
Also, the measurement gas introducing hole H _1, after the measurement gas impinging on the detection unit 11 between the center to the base end of the cover member 20 of the detection unit 11 is upward, in the upstream side to the lower side In order to form a space for generating a circulating vortex, it is drilled at a position separated by a vortex formation distance L ₁ from the base end of the cover body 20.
Further, between the center of the detection unit 11 and the tip of the cover body 20, after a part of the gas to be measured colliding with the detection unit 11 heads downward, a space for generating a vortex that circulates upstream is generated. to form, the swirl distance L ₂ from the center of the detector 11 to the tip of the cover member 20 is provided.

Width W ₂ horizontal side outlet hole H ₂ is the horizontal width W smaller side outlet hole opening width upper limit W than _E which is defined by the intersection of the straight line obtained by projecting the side edge on the cover member 20 of the detection element 10 _2HL set below, set over larger side outlet hole opening width lower limit W _2LL than 1/2 of the width W _E which is defined by the intersection of the straight line obtained by projecting the side edge on the cover member 20 of the detection element 10 Has been.
Opening height of side outlet holes H ₂ T ₂ is set to 1/2 larger side outlet hole vertical width than the lower limit value T _2LL than the vertical width of the detection unit 11.

The opening diameter φD ₃ of the lower surface outlet hole H ₃ is equal to or lower than the lower surface outlet hole opening lateral width upper limit value H _3HL of the inner diameter φD ₂₀ of the cover body 20 and is larger than the thickness t ₁₀ of the detecting element 10. H _3LL or more is set.
The lower surface outlet hole H ₃ is, as shown in this embodiment, may be formed by a single hole, but may be constituted by a plurality holes.

Specifically, for example, the width _{W 11} of the detector 11 2mm 10mm or more or less, when the longitudinal width _{T 11} is 2mm or more 10mm or less, the opening width _{W 1} of the measurement gas introducing hole _{H 1} is 1mm or more 10mm hereinafter, the opening longitudinal width _{T 1} of the measurement gas introducing hole _{H 1} is 1mm or more 10mm or less, a side outlet opening width _{W 2} of the hole _{H 2} is 5mm or more 10mm or less, an opening longitudinal width T2 of the side outlet hole _{H 2} is 10mm or more opening diameter φD3 the lower surface lead-out hole and H3 5mm or more, a distance _{L 1} from the proximal end of the cover body 20 to the opening position of the measurement gas introducing hole _{H 1} is 10mm or more 30mm or less, the measurement gas introducing hole _{H 1} opening distance _{L 2} to the tip of the cover body 20 is set to 5mm or more 15mm or less from the position.

The effects of the present invention will be described with reference to FIGS.
The measured gas introduced into the cover body 20 from the measured gas introduction hole H ₁ collides with the detection unit 11 and deposits PM contained in the measured gas on the surface of the detection unit 11.
In this case, the measurement gas introduced into the cover body 20 is distributed vertically and horizontally, but is derived from the side outlet hole H ₂ and the lower surface outlet hole H ₃ Metropolitan out of the cover body 20, the cover body 20 It collides with the gas to be measured flowing around or drawn into the gas to be measured, and the flow direction changes to the downstream side.
Furthermore, some of the measurement gas flowing cover body 20, cover the flow rate and the side lead-out hole H ₂ and the lower surface outlet hole H ₃ Metropolitan when introduced into the cover body 20 from the gas introduction hole H ₁ to be measured A vortex that circulates toward the upstream side of the detection unit 11 is generated due to a difference from the flow velocity when being led out of the body 20 or a pressure distribution generated in the cover body 20. The flow rate of the gas to be measured introduced is suppressed.
For this reason, it is possible to keep the PM deposited on the surface of the detection unit 11 from being deposited on the detection unit 11 without being caused to flow by the gas to be measured introduced into the cover body 20.

With reference to FIG. 5 to FIG. 9, a configuration in which the effect of the present invention cannot be exhibited will be described.
Like the cover body 20 _Z shown in FIG. 5A as the comparative example 1, the opening lateral width W _1Z of the gas introduction hole H _{1Z to} be measured is a straight line obtained by projecting the side edge of the detection element 10 onto the cover body 20. If it is the width W ₁₀ or more which is defined by intersection, the cover member 20 the flow velocity of the measurement gas introduced into the _Z is not suppressed, directly side derived from the measurement gas introducing hole H _1Z hole H ₂ As in the case where the detection element 10 is not covered with the cover body, the particulate matter may not easily accumulate on the detection unit 11.
Further, the horizontal width _defined by the intersection of the opening horizontal width W _1Y of the measured gas introduction hole H _1Y and the straight line projected from the side edge of the detection unit 11 on the cover body 20 shown as Comparative Example 2 in FIG. when W is ₁₀ less than half the predetermined introduction hole opening width lower limit W _1LL following is on the absolute amount of the amount of the measurement gas introduced into the cover body 20 in _Y is reduced, the measured There is a possibility that the gas flow rate is excessively suppressed and PM is difficult to deposit on the detection unit 11.

The opening vertical width T _1X of the measured gas introduction hole H _1X shown in FIG. _6A as Comparative Example 3 is _{equal to} or larger than a predetermined introduction hole opening vertical width upper limit T _1HL larger than the vertical width T ₁₁ of the detection unit 11. in this case, the flow velocity of the measurement gas introduced into the cover body is not sufficiently suppressed, the flow directed directly to the lower surface outlet hole H ₃ from the measurement gas introducing hole is formed, the cover body detection element 10 As in the case where it is not covered by 20, there is a risk that PM will not easily accumulate on the detection unit 11.
In addition, an introduction hole longitudinal width lower limit T _{1L in which} the opening longitudinal width T _1W of the measured gas introduction hole H _1W is smaller than ½ of the longitudinal width T ₁₁ of the detection unit 11 shown as Comparative Example 4 in FIG. the case is less, on the absolute amount of the measurement gas introduced into the cover body 20 _W is reduced, a possibility that the flow rate of the measurement gas is excessively suppressed, and it becomes difficult PM is deposited in the detection unit 11 There is.

As a comparative example 5 in FIG. 7 (a), the width W _2V aspect lead hole H _2V is than the width W _E which is defined by the intersection of the projection of the side edges of the detection element 10 to the cover body 20 _V linear When the large predetermined side surface outlet hole width upper limit W _{2HL is} exceeded, a flow is formed directly from the measured gas introduction hole H ₁ toward the side surface outlet hole H _{2 V} , and the detection element 10 is covered by the cover body 20. Similarly to the case where the PM is not present, there is a possibility that PM is difficult to deposit on the detection unit 11.
Further, the width W which is defined by the intersection of the straight line as a comparative example 6, the opening width W _2U side outlet hole H _2U obtained by projecting the side edge of the detection element 10 to the cover body 20 _V in FIG. 7 (b) If _E is less than 1/2 of the once from the cover body 20 _U the measurement gas introduced into the not easily derived to the outside of the cover body 20 _U, resulting in the measurement gas introducing hole H ₁ the flow rate of the measurement gas is reduced to be introduced into the cover member 20 within _U, not formed the flow of the measurement gas impinging on the detection unit 11, there is a possibility that PM is hardly deposited.

If 8 opening longitudinal width T ₂ of the side outlet holes H ₂ as a comparative example 7 (a) is less than half the height of detector 11, the introduced into the cover body 20 _T is derived is excessively suppressed measurement gas, for staying in the cover body 20 _T, the introduction of the assumed gas is excessively suppressed, there is a possibility that PM in the detection unit 11 is less likely to deposit.

As a comparative example 8 in FIG. 8 (b), the opening diameter [phi] D _3S lower surface lead-out hole _{H 3S} is equal to or less than the thickness _{T 10} of the detecting element 10, the measurement gas derived from the lower surface outlet hole _{H 3S} are less likely, since the staying in the cover body 20 in the _S, introduction of the assumed gas is excessively suppressed, there is a possibility that the particulate matter hardly deposits on the detector 11.

As a comparative example 9 in FIG. 9 (a), without the position opposite to the detection portion 11 of the opening position detecting element 10 of the measurement gas introducing hole H _1R, the distance L _1R from the proximal end of the cover body 20 _R , is shorter than 10mm, the vortex is not generated in the cover member 20R, a strong flow of unilaterally directed is formed on the lower surface outlet hole H _3, is a possibility that PM accumulated in the detecting section 11 is easily desorbed is there.
As a comparative example 10 in FIG. 9 (b), the opening position of the measurement gas introducing hole _{H 1Q} is not in a position facing the detecting unit 11 of the detecting element 10, the distance from the proximal end of the cover body 20 _{Q L 1Q} However, if it is longer than 30 mm, a flow directed directly from the measured gas introduction hole H _1Q to the lower surface outlet hole H ₃ is formed, and PM does not reach the surface of the detection unit 11 and may not be easily deposited. is there.

FIG. 10 shows an example of the effect of the present invention together with a comparative example.
This figure (a) is a photograph which shows a mode that PM deposited on the detection part 11 of the particulate matter detection sensor 1 in the 1st Embodiment of this invention, and this figure (b) is a cover body as a comparative example. 20 is a photograph showing a PM deposition state when the detection element 10 is not covered by the sensor 20.
As shown in FIG. 4A, when the detection element 10 is covered with the cover body 20 that is the main part of the present invention, PM is concentrated in a specific range on the surface of the detection unit 11. I understand that.
On the other hand, as shown in this figure (b), when the cover body 20 which is the principal part of this invention is not provided, PM accumulates slightly on the whole surface of the detection element 10.

With reference to FIG. 11, the modification of the cover body 20 which is the principal part of this invention is demonstrated.
This figure (a) is a perspective view which shows the cover body 20 in the 1st Embodiment of this invention.
As shown in this figure (b), a plurality of side surface outlet holes H ₂ may be formed side by side in the axial direction of the cover body 20. Further, as shown in the above embodiment, a side outlet hole H ₂ may be formed in a circular shape, as shown in the figure (c), may be formed side outlet hole H _2b rectangular. Furthermore, as shown the figure (d), it may be formed in a long hole shape extending side outlet hole H _2c in the axial direction of the cover body 20c. In this case, if the lateral width W ₂ of the side surface outlet holes H ₂ , H _2b , H _2c is set in the above range, the flow velocity of the gas to be measured introduced into the cover bodies 20, 20a, 20b, 20c is It is suppressed moderately, and PM is easily deposited on the detection unit 11.
Furthermore, as shown in FIG. 4E, the lower surface outlet hole H _3d may be configured by a plurality of openings. In this case, the lower surface lead-out hole H _3d located upstream of the detection element 10 functions as a lead-out hole for leading the gas to be measured from the cover body 20d in the distal direction, and the lower surface lead-out located downstream of the detection element 10 is derived. The hole H _3d functions as an introduction hole that balances the pressure inside and outside the cover body 20d on the back side of the detection element 10 in the cover body 20d.
Moreover, as shown in this figure (f), you may form the lower half part of the front end side of the cover body 20e in a taper shape.

Another embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 12A as Example 2, even when the lateral width W _4g of the back side pressure adjustment hole H _4g is drilled larger than the lateral width W 10 in the detection element 10, the measurement target derived from the side surface outlet hole H ₂ Although some of the gas vortex to reflux on the back side of the detecting element 10 is formed, any not affect the flow of the measurement gas towards the detection unit 11 is introduced from the gas introduction hole H ₁ to be measured, above The same effect as that of the particulate matter detection sensor according to the first embodiment can be exhibited. Further, as shown in the figure (b) Example 3, backside pressure adjusting hole in the detecting unit 11 a longitudinal width T _4h of H _4h even when the larger bored than the vertical width T _11, the lower surface outlet hole H ₃ A vortex flow is formed in which part of the measured gas derived from circulates to the back side of the detection element 10, but has no effect on the flow of the measured gas introduced from the measured gas introduction hole H ₁ toward the detection unit 11. The same effects as those of the particulate matter detection sensor in the first embodiment described above can be exhibited.

Further, as shown in FIG. 13, the opening diameter φD _3i of the lower surface outlet hole H _3i may be formed equal to the inner diameter φD ₂₀ of the cover body 20 _i .
If the lower surface outlet holes H ₃ and H _3i have an opening diameter equal to or larger than the plate thickness t ₁₀ of the detection element 10, the flow of the gas to be measured and the cover body 20 derived from the lower surface outlet holes H ₃ and H _3i. , and balance the flow of the measurement gas flowing beneath the tip of the 20i, regardless of the opening diameter of the lower surface outlet hole H _3, the relationship between the gas introduction hole H ₁ and side outlet hole H ₂ to be measured The determined flow is maintained.

About the effect of this invention, FIGS. 14-16 shows the PM collection amount of the above-mentioned Example 1, 2, 3 and Comparative Examples 1-10.
As shown in FIG. 14 (a), the opening width W ₁ of the measurement gas introducing hole H ₁ is the width W ₁₀ that is defined by the intersection of the projection of the side edges of the detection element 10 to the cover body 20 linearly Predetermined introduction hole having a lateral width W ₁₀ or less, which is set to be equal to or more than a predetermined introduction hole lateral width lower limit W _{1LL of} ½ or more and defined by the intersection with the straight line projected on the cover body 20 at the side edge of the detection element 10 When the lateral width upper limit value W is set to 1 _HHL or less, the amount of collected PM is larger than that of the case without the cover body shown as the comparative example.
As shown in FIG. 14B, the opening vertical width T ₁ of the measured gas introduction hole H ₁ is equal to or greater than a predetermined introduction hole vertical width lower limit T _{1LL that} is 1/2 or more of the vertical width T ₁₁ of the detection unit 11. is set to, the amount of the trapped PM than without the cover member shown as a comparative example when the vertical width T ₁₁ is set to be less than the following predetermined introduction hole vertical width upper limit T _1HL detection unit 11 more It has become.

As shown in FIG. 15 (a), the width W ₂ horizontal side outlet hole H ₂ is than the width W _E which is defined by the intersection of the projection of the side edges of the detection element 10 to the cover body 20 linearly is set in the following also small side outlet hole opening width upper limit W _2HL, larger side value than 1/2 of the width W _E which is defined by the intersection of the straight line obtained by projecting the side edge of the detection element 10 to the cover body 20 When the hole opening lateral width lower limit value W _2LL is set, the amount of PM trapped is larger than that in the case of no cover body shown as a comparative example.
As shown in FIG. 15B, the opening length T ₂ of the side surface outlet hole H ₂ is set to be _{equal to} or larger than the side surface outlet hole vertical width lower limit value T _2LL which is larger than ½ of the vertical width of the detection unit 11. In this case, the amount of collected PM is larger than the case without the cover body shown as the comparative example.
As shown in FIG. 16A, the opening diameter φD ₃ of the lower surface outlet hole H ₃ is equal to or lower than the lower surface outlet hole opening lateral width upper limit value H _3HL of the inner diameter φD ₂₀ of the cover body 20, and the thickness t of the detection element 10 _{When the} lower surface outlet hole opening lateral width lower limit H _3LL is larger than _{10, the} amount of collected PM is larger than that in the case of no cover body shown as a comparative example.
As shown in FIG. 16 (b), the size of the pressure adjusting hole H ₄ does not particularly affect the amount of PM trapped, and the gas to be measured is introduced or led out by the pressure balance in the cover body 20.

The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention.
For example, in the above embodiment, the particulate matter detection sensor mounted on an internal combustion engine such as an automobile engine has been described as an example, but the particulate matter detection sensor of the present invention is not limited to being mounted on a vehicle, It can also be used for particulate matter detection in large-scale plants such as thermal power plants.

DESCRIPTION OF SYMBOLS 1 Particulate matter detection apparatus 10 Detection element 11 Detection part 20 Cover body 21 Flange part 22 Perimeter wall part 23 Bottom part H ₁ Gas introduction hole H ₂ Side surface extraction hole H ₃ Bottom surface extraction hole H ₄ Back side pressure adjustment hole L ₁ detection Cover body base end distance L ₂ detection unit cover end distance L ₁ + L ₂ cover body length W ₁ introduction hole lateral width W _1LL introduction hole lateral width lower limit value W _1HL introduction hole lateral width upper limit value W ₂ side surface outlet hole lateral width T ₁ Introduction hole vertical width T _1LL Introduction hole vertical width lower limit T _1HL introduction hole vertical width upper limit 30 Insulator 40 Housing 41 Screw part 42 Clamping part

JP 59-197847 A JP 2009-97868 A

Claims (19)

A front end of a detection element formed in a substantially flat plate shape having a predetermined horizontal width, length, and thickness is placed in a gas flow path to be measured, and has a predetermined horizontal width and vertical width provided on the front end side of the detection element. A particulate matter detection sensor for detecting a particulate matter contained in a gas to be measured by detecting a physical quantity that varies depending on the amount of particulate matter deposited on a detection unit,
The detection unit is made to face the upstream side of the gas flow path to be measured, and a substantially cylindrical cover body having a predetermined inner diameter and length covering the tip of the detection element including the detection unit is provided,
The cover body is at least
While facing the detection unit, it opens toward the upstream side of the gas to be measured and introduces the gas to be measured into the cover body, or a circular gas to be measured introduction hole,
A rectangle that opens toward both sides of the detection unit and leads the measurement gas introduced into the cover body in a side surface direction, or a circular side surface lead-out hole;
A rectangular opening for opening the gas to be measured introduced into the cover body to the lower side of the distal end, or a circular lower surface outlet hole, which opens toward the lower side of the distal end of the detection unit,
The opening width and opening length of each of the measured gas introduction hole, the side surface outlet hole, and the lower surface outlet hole, or the opening diameter is defined in a range from a predetermined lower limit value to an upper limit value, and
Defining at least the distance from the base end of the cover body to the opening position of the gas inlet hole to be measured and the distance from the opening position of the gas inlet hole to be measured to the tip of the cover body;
The flow of the gas to be measured that collides with the detection unit is distributed to the top, bottom, left, and right, and is generated outside the cover body from the side surface extraction hole and the bottom surface extraction hole, and is generated upstream of the detection unit in the cover body. A particulate matter detection sensor, characterized in that the flow velocity of the gas to be measured introduced into the cover body is suppressed by eddy currents.   The upper limit value of the opening width of the measured gas introduction hole is smaller than the width defined by the intersection with the straight line obtained by projecting the side edge of the detection element onto the cover body, and the opening width of the measured gas introduction hole 2. The particulate matter detection sensor according to claim 1, wherein a lower limit value of the particulate matter is larger than ½ of a lateral width defined by an intersection with a straight line obtained by projecting a side edge of the detection element onto the cover body.   The upper limit of the opening vertical width of the measurement gas introduction hole is smaller than the vertical width of the detection part, and the lower limit of the opening vertical width of the measurement gas introduction hole is less than 1/2 of the vertical width of the detection part. The particulate matter detection sensor according to claim 1 or 2, wherein the particulate matter detection sensor is larger.   The upper limit value of the lateral width of the side surface outlet hole is smaller than the lateral width defined by the intersection with the straight line obtained by projecting the side edge of the detection element onto the cover body, and the lower limit value of the lateral width of the side surface outlet hole is The particulate matter detection sensor according to any one of claims 1 to 3, wherein a side edge of the detection element is larger than ½ of a lateral width defined by an intersection with a straight line projected onto the cover body.   The particulate matter detection sensor according to any one of claims 1 to 4, wherein a lower limit value of an opening vertical width of the side surface lead-out hole is larger than ½ of a vertical width of the detection unit.   An upper limit value of the opening diameter of the lower surface outlet hole is equal to or smaller than an inner diameter of the cover body, and a lower limit value of the opening diameter of the lower surface outlet hole is defined by an intersection with a straight line projected on the side edge of the detection element on the cover body. The particulate matter detection sensor according to any one of claims 1 to 5, wherein the particulate matter detection sensor is larger than ½ of a lateral width of the particulate matter.   The particulate matter detection sensor according to any one of claims 1 to 6, wherein a plurality of the side lead-out holes are formed side by side in the axial direction of the cover body.   The particulate matter detection sensor according to any one of claims 1 to 6, wherein the side surface outlet hole is formed in a long hole shape extending in the axial direction of the cover body.   The particulate matter detection sensor according to any one of claims 1 to 8, wherein an inner diameter of the cover body is not more than twice a lateral width of the detection element.   The particulate matter detection sensor according to any one of claims 1 to 9, wherein a predetermined vortex formation distance is provided from a base end of the cover body to an opening position of the measurement gas introduction hole.   The particulate matter detection sensor according to any one of claims 1 to 10, wherein a predetermined vortex forming distance is provided from an opening position of the measurement gas introduction hole to a tip of the cover body.   The particle according to any one of claims 1 to 11, wherein when the horizontal width of the detection section is 2 mm or more and 10 mm or less and the vertical width is 2 mm or more and 10 mm or less, the opening horizontal width of the measurement gas introduction hole is 1 mm or more and 10 mm or less. A substance detection sensor.   The opening vertical width of the measurement gas introduction hole is 1 mm or more and 10 mm or less when the horizontal width of the detection unit is 2 mm or more and 10 mm or less and the vertical width is 2 mm or more and 10 mm or less. Particulate matter detection sensor.   The particulate matter detection sensor according to any one of claims 1 to 13, wherein when the lateral width of the detection element is 10 mm or less, the lateral width of the side lead-out hole is 5 mm or more and 10 mm or less.   The particulate matter detection sensor according to any one of claims 1 to 14, wherein when the lateral width of the side surface outlet hole is 10 mm or less, the vertical width of the side surface outlet hole is 5 mm or more and 10 mm or less.   The particulate matter detection sensor according to any one of claims 1 to 15, wherein when the lateral width of the detection element is 10 mm or less, the opening diameter of the lower surface lead-out hole is 5 mm or more.   The particulate matter detection sensor according to any one of claims 1 to 16, wherein a distance from a base end of the cover body to an opening position of the measurement gas introduction hole is 10 mm or more and 30 mm or less.   The particulate matter detection sensor according to any one of claims 1 to 17, wherein a distance from an opening position of the measurement gas introduction hole to a tip of the cover body is 5 mm or more and 15 mm or less.   The physical quantity is any one of a resistance value, capacitance, impedance, oxidation-reduction potential, or a combination of physical quantities selected from these, which varies depending on the amount of particulate matter deposited on the detection unit. The particulate matter detection sensor according to any one of 18.