JP4315656B2 - Gas sensor mounting structure and mounting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a protector that is used in a state exposed to a gas to be measured, such as an oxygen sensor and a NO _x sensor, and that protects a gas detection element housed in the gas from moisture contained in the gas to be measured. The present invention relates to a gas sensor and a structure for mounting the gas sensor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, gas sensors that are attached to an internal combustion engine such as an automobile engine and detect a specific gas component in exhaust gas (a gas to be measured) have been developed. As one of them, a gas sensor (oxygen sensor) that detects a gas concentration using a solid electrolyte such as zirconia, for example, and an NO _x sensor that detects a nitrogen oxide gas concentration are known. .
[0003]
In general, this type of gas sensor has a structure in which a gas contact portion formed on the gas detection element is exposed to exhaust gas, and the gas detection element is heated to a high temperature (about 300 ° C.) using a heater. It activates and detects specific gas components in the exhaust gas.
By the way, since the gas detection element is made of ceramic and is fragile to thermal shock, if moisture in the exhaust gas adheres to the gas detection element heated to a high temperature, the gas detection element breaks due to a crack or the like. There is a fear.
[0004]
For this reason, a protector that covers the gas contact portion of the gas detection element is attached to the gas sensor to protect the gas detection element from water droplets.
This protector has an inlet and an outlet for the gas to be measured on the side wall and bottom wall, introduces the gas to be measured from the inlet of the protector, leads it to the gas contact portion of the gas detection element, and discharges it from the outlet. Introduce and discharge the gas to be measured.
[0005]
As such a protector, a gas sensor having a double structure composed of an inner cylindrical portion (first cylindrical portion) and an outer cylindrical portion (second cylindrical portion) is disclosed in Japanese Patent Laid-Open No. 2001-099807. Yes.
In the gas sensor disclosed in Japanese Patent Application Laid-Open No. 2001-099807, the side wall of the inner cylindrical portion and the side wall of the outer cylindrical portion are arranged coaxially with a gap between them, and a gas inlet to be measured ( A first side gas inlet and a second side gas inlet) are formed. Moreover, the guide body for generating the swirl | flow which surrounds the side wall outer surface of an inner side cylindrical part is arrange | positioned at the inlet of an outer side cylindrical part. Then, the specific gas component in the measurement gas is detected by causing the measurement gas to flow into the inner cylindrical portion from the inlet of the inner cylindrical portion and contact the gas detection element. Thereafter, the gas to be measured is passed through the discharge port (first gas outlet) provided on the bottom wall of the inner cylindrical part, and discharged from the discharge port (second gas outlet) provided on the bottom wall of the outer cylindrical part. I am letting.
[0006]
[Problems to be solved by the invention]
By the way, the exhaust pipe to which the gas sensor is attached is not necessarily formed in a straight line and may be meandered.
An example of attachment of the gas sensor and the exhaust pipe will be described with reference to FIG.
[0007]
FIG. 1B is a diagram showing an example in which the gas sensor protector 4 is attached to the meandering exhaust pipe P1, and FIG. 1C shows the sensor center of the gas sensor protruding from the linear exhaust pipe P2. It is a figure showing the example which inclined and attached the axis | shaft U (henceforth the sensor axis | shaft U).
[0008]
As shown in FIG. 1B, when the protector 4 of the gas sensor is attached to the meandering exhaust pipe P1, if the attachment positions are different as shown in S1 and S2, the gas to be measured is measured with respect to the sensor axis U of the gas sensor. The flowing direction Q is different.
In addition, as shown in FIG. 1C, even when a straight exhaust pipe P2 is used, the sensor shaft U of the gas sensor may be attached with an inclination due to restrictions on the structure around the exhaust pipe. When the inclination angle is different, the direction Q of the gas to be measured flows with respect to the sensor axis U of the gas sensor.
[0009]
Therefore, even if the direction Q of the measurement gas flows with respect to the sensor axis U of the gas sensor, the measurement gas in the protector can be satisfactorily replaced, and a response for detecting a specific gas component of the measurement gas. There is a need for a gas sensor mounting structure that is excellent in performance and detection accuracy.
[0010]
However, according to the gas sensor disclosed in Japanese Patent Laid-Open No. 2001-099807, the bottom wall having the discharge port exposed to the outside and the side wall having the introduction port in the protector are formed substantially at right angles. If the gas sensor is attached to the exhaust pipe so that the direction Q of the gas to be measured flows obtusely with respect to the sensor axis U of the gas sensor, the gas to be measured in the protector becomes insufficiently replaced. There has been a problem that the detection accuracy for detecting the component depends on the direction of attachment to the exhaust pipe.
[0011]
That is, the gas sensor in which the bottom wall of the outer cylindrical portion having the discharge port and the side wall of the outer cylindrical portion are formed in a substantially right angle is like S1 in FIG. 1 (b) or S3 in FIG. 1 (c). When the sensor axis U of the gas sensor is inclined at an obtuse angle with respect to the flow direction Q of the gas to be measured, the bottom wall is inclined so as to face the gas to be measured flowing in the exhaust pipe P1, and the gas to be measured Will flow in a direction that hits the bottom wall with the measured gas discharge port, so that the measured gas discharged from the inside of the protector through the discharge port is prevented from being discharged, and further, the measured gas is discharged from the discharge port. May flow in.
[0012]
On the other hand, as shown in S2 of (b), when the sensor axis of the gas sensor is inclined at an acute angle with respect to the flow direction Q of the gas to be measured, a negative pressure is generated on the bottom surface of the discharge port, and from the inside of the protector. The discharge of measured gas is promoted.
As a result, as shown in S1 of FIG. 1B and S3 of FIG. 1C, when the inclination angle between the flow direction Q of the gas to be measured and the sensor axis U of the gas sensor becomes an obtuse angle, the gas of the gas to be measured There has been a problem that the response speed for detecting the component is delayed or the detection accuracy is impaired.
[0013]
The present invention has been made in view of such problems. Even when the gas sensor is attached to the exhaust pipe, even if the gas sensor is attached so that the direction in which the gas to be measured flows is obtuse with respect to the sensor axis of the gas sensor, the object in the protector is not provided. An object of the present invention is to provide a gas sensor mounting structure capable of satisfactorily replacing a measurement gas and having excellent responsiveness and detection accuracy for detecting a gas component of the gas to be measured.
[0014]
[Means for Solving the Problems and Effects of the Invention]
In order to achieve this object, the invention according to claim 1 covers the gas contact portion that contacts the gas to be measured formed on the tip side of the gas detection element, and forms an inlet for the gas to be measured on the side wall. In addition, an outlet for a gas to be measured is formed in the bottom wall, and at least a portion of the side wall connected to the bottom wall and exposed to the outside has a small outer diameter toward the bottom wall. A gas sensor mounting structure in which a gas sensor provided with a protector having a taper portion with a taper is attached and protrudes into the exhaust pipe, and the outside angle at which the taper portion intersects the bottom wall is β °, and the axial direction of the gas sensor is When the axial inclination angle of the gas sensor to be inclined with respect to the flow direction of the gas to be measured is α °, α ° is an obtuse angle, 135 ° or less, and β ° is 45 ° or less, β ° ≦ (180 ° − α °) A mounting structure of a gas sensor and wherein the mounting so as to satisfy the equation.
[0015]
According to the gas sensor mounting structure of claim 1, when the gas sensor is mounted on the exhaust pipe, the protector may be mounted even if the sensor axis of the gas sensor is mounted at an obtuse angle with respect to the direction in which the gas to be measured flows. The effect of being able to satisfactorily replace the gas to be measured and to improve the responsiveness and detection accuracy of detecting the gas component of the gas to be measured was obtained through experiments.
[0016]
That is, as shown in FIG. 1 (a), the direction Q of the gas to be measured flows with an obtuse angle with respect to the sensor axis U of the gas sensor (in other words, the axis tilt angle α ° of the gas sensor becomes an obtuse angle). When the gas sensor is attached to the exhaust pipe, a tapered portion having an outer angle of β ° intersecting with the bottom wall is formed on the side wall of the protector of the gas sensor as described above, and the relational expression of β ° ≦ (180 ° −α °) is satisfied. When the gas sensor is attached as described above, the gas to be measured flowing around the outer periphery of the protector 4 comes into contact with the tapered portion 22, and a gas flow Q <b> 2 flowing in the direction of the bottom wall 17 of the protector 4 is generated along the tapered portion 22. The gas flow Q2 and the flow Q of the gas to be measured merge in the vicinity of the bottom wall 17, so that the flow pressure received by the bottom wall 17 of the protector 4 due to the flow direction Q of the gas to be measured is reduced. Since a negative pressure is generated in the vicinity of the discharge port 15 of the wall 17, the discharge of the measurement gas from the inside of the protector 4 is not hindered by the flow Q of the measurement gas, so that it can be quickly discharged from the discharge port 15 in the measurement gas. The response speed and the detection accuracy for detecting the gas component can be improved.
[0017]
The axial inclination angle α ° of the gas sensor is preferably 135 ° or less. The reason is that if the axial inclination angle α ° of the gas sensor exceeds 135 °, the response speed for detecting the gas component of the gas to be measured increases.
Moreover, it is preferable that the axial inclination angle α ° of the gas sensor is 135 ° and the outer angle β ° at which the taper of the protector intersects the bottom wall is 45 ° or less. The reason is that when the axial inclination angle α ° of the gas sensor exceeds 135 °, the response speed for detecting the gas component of the gas to be measured increases, and the outer angle β ° at which the taper portion of the protector intersects the bottom wall is 45 °. This is because the flow pressure received by the bottom wall of the protector due to the flow direction Q of the measured gas is further reduced, and the response speed for detecting the gas component in the measured gas is improved.
[0018]
Next, the invention according to claim 2 covers the gas contact portion that is in contact with the gas to be measured formed on the front end side of the gas detection element, forms an inlet for the gas to be measured on the side wall, and A discharge port for the gas to be measured is formed, and at least a tip of the side wall connected to the bottom wall and exposed to the outside is tapered so that the outer diameter becomes smaller toward the bottom wall. A gas sensor mounting method in which a gas sensor including a protector formed with a taper portion is protruded into the exhaust pipe and attached to the exhaust pipe, the outer angle at which the taper portion intersects the bottom wall is β °, and the axial direction of the gas sensor is When the axial inclination angle of the gas sensor to be inclined with respect to the flow direction is α °, α ° is an obtuse angle, 135 ° or less, and β ° is 45 ° or less, β ° ≦ (180 ° −α °) To satisfy the relational expression A method of mounting a gas sensor characterized in that it delivers.
[0019]
According to the gas sensor mounting method of the second aspect, as in the first aspect of the invention, when the gas sensor is mounted on the exhaust pipe, the sensor axis of the gas sensor is obtuse with respect to the direction in which the gas to be measured flows. Even if it is attached so as to be inclined, it is possible to satisfactorily replace the gas to be measured in the protector, and to improve the response and detection accuracy for detecting the gas component of the gas to be measured.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
2 is a cross-sectional view showing a configuration of a gas sensor according to an embodiment to which the present invention is applied, FIG. 3 is a half cross-sectional view showing an inner cylindrical portion in the gas sensor of the embodiment, and FIG. 4 is an outer cylindrical shape in the gas sensor of the embodiment. They are a half sectional view showing a section and a BB sectional view in a figure.
[0026]
2 to 4, reference numeral 1 denotes a gas sensor. The gas sensor 1 includes a gas detection element 2 having a gas contact portion that is brought into contact with a gas to be measured on the tip side (lower side in the figure), and a gas contact portion from the tip. A cylindrical case 3 that holds the gas detection element 2 in a protruding state, and a bottomed cylindrical protector that is fixed to the outer periphery on the front end side of the case 3 so as to cover the periphery of the gas contact portion of the gas detection element 2 4 is provided.
[0027]
As shown in FIG. 2, the gas detection element 2 is fixed to the case 3 via a ceramic holder 52, talc powder 53, and a ceramic sleeve 54 arranged from the front end side of the case 3. An outer cylinder 55 is fixed to the outer periphery of the rear end side of the case 3 by welding or the like. Further, on the inner side of the rear end side of the outer cylinder 55, a ceramic separator 57 and a grommet 59 through which a lead wire 56 for making an electrical connection with the gas detection element 2 to the outside through the lead frame 51 is inserted, Is arranged. The ceramic separator 57 is formed with a flange portion 58 projecting outward on the outer peripheral surface of the substantially center in the axial direction, and the outer support portion formed in a form in which the flange portion 58 projects inwardly in the outer cylinder 55. 60. The grommet 59 is elastically fitted inside the outer cylinder 55.
[0028]
The protector 4 includes an inner cylindrical portion 6 and an outer cylindrical portion 7 that is coaxially disposed outside the inner cylindrical portion 6 with a gap 8 therebetween, and is formed in a double structure.
On the side wall 12 of the outer cylindrical portion 7, an outer wall gas introduction port 13 provided with a guide body 10 extending inward to introduce a gas to be measured into the gap 8 is provided at 45 ° intervals on the circumference. A plurality are formed (see FIG. 4B). The guide body 10 is formed by bending the tangent line on the outer periphery of the outer cylindrical portion 7 inward at approximately 45 degrees. Further, the guide body 10 is formed by cutting the side wall 12 of the outer cylindrical portion 7 into a U-shape as shown in FIG. 4 and bending the cut piece. The guide body 10 has a function of generating a swirling flow in a state in which the gas to be measured surrounds the outer peripheral surface of the inner cylindrical portion 6, and the inertial force generated by the swirling flow causes relative to a relatively heavy water droplet. Thus, the light gas component is separated.
[0029]
In the side wall 9 of the inner cylindrical portion 6, in order to introduce the gas to be measured around the gas detection element 2, the inner wall gas introduction port 11 is located closer to the case 3 than the outer wall gas introduction port 13. It is formed so as to face the element 2. Further, the inner wall gas introduction ports 11 are arranged to be shifted by 22.5 ° in the circumferential direction with respect to the outer wall gas introduction ports 13, and a plurality of inner wall gas introduction ports 11 are formed at intervals of 45 ° in the circumference. The outer peripheral surface of the side wall 9 of the inner cylindrical portion 6 at a position facing the outer wall gas inlet 13 is formed in parallel with the outer peripheral surface of the side wall 12 of the outer cylindrical portion 7.
[0030]
In the gas sensor 1, the inner cylindrical portion 6 is formed in a bottomed cylindrical shape, and the outer cylindrical portion 7 is formed in a bottomed cylindrical shape. The gas sensor 1 is inserted in the bottom wall 16 of the outer cylindrical portion 7. The inner cylindrical portion 6 is inserted into the hole 25 (see FIG. 4A), and the bottom wall 17 of the inner cylindrical portion 6 protrudes from the bottom wall 16 of the outer cylindrical portion 7 to the front end side. A discharge port 15 is formed in the bottom wall 17 of the shaped part 6. That is, the bottom wall 17 of the inner cylindrical portion 6 becomes a bottom wall located on the most distal side of the protector 4.
[0031]
Further, a tapered portion 22 that is tapered on the side wall 9 of the inner cylindrical portion 6 that protrudes toward the distal end side from the bottom wall 16 of the outer cylindrical portion 7 so that the outer diameter becomes smaller toward the distal end side is provided. Is formed.
The taper portion 22 is formed such that β ° is 60 ° or less when the outer angle intersecting the bottom wall 10 is β ° (β ° in FIG. 2).
[0032]
When the gas sensor 1 is attached to the exhaust pipe, the gas sensor attachment structure and method may be performed as follows.
A gas sensor mounting structure and method will be described with reference to FIG.
FIG. 1A is an explanatory diagram of a gas sensor mounting structure and a mounting method. In the configuration of the gas sensor 1 shown in FIG. 2, the protector 4 part that appears on the exhaust pipe is shown, and the other constituent parts are shown. Omitting.
[0033]
In FIG. 1A, the protector 4 is formed with a sloped tapered portion 22 whose outer diameter decreases in the axial direction toward the tip, and a discharge port 15 is formed in the most advanced bottom wall 17. In FIG. 1A, illustration of the outer cylindrical portion 7 is omitted, and only the inner cylindrical portion 6 is shown.
[0034]
And the protector 4 is attached so that it may protrude in the exhaust pipe into which to-be-measured gas flows.
At this time, the outside angle at which the taper portion 22 intersects the bottom wall 17 is β °, the gas sensor axis U direction is inclined with respect to the gas flow direction Q, the gas sensor axis inclination angle is α °, and α ° is an obtuse angle. At this time, the gas sensor may be mounted in the exhaust pipe through which the gas to be measured flows so as to satisfy the relational expression of β ° ≦ (180 ° −α °).
[0035]
Below, the result of having performed the response speed test which detects the gas component in to-be-measured gas is demonstrated.
The gas sensor 1 used here has an outer diameter of the outer cylindrical portion 7 of the protector 4 of about 15 mm, an outer diameter of the side wall of the inner cylindrical portion 6 in which the inner wall gas inlet 11 is formed, about 9 mm, The protruding dimension from the bottom wall 16 of the outer cylindrical part 7 to the bottom wall 17 of the inner cylindrical part 6 is 2.8 mm, the diameter of the discharge port 15 is approximately 2 mm, and the diameter of the inner wall gas inlet 11 is approximately 3. The diameter of the outer wall gas inlet 13 was about 4 mm, and the size of the gap 8 between the outer cylindrical portion 7 and the inner cylindrical portion 6 was about 5 mm.
[0036]
Moreover, in order to confirm the effect of this embodiment, the gas sensor which does not form the taper part 22 in the side wall 9 of the inner side cylindrical part 6 was prepared as a comparative example, and the test was done with Examples 1-3 of this embodiment. .
In the response speed test, the protector 4 was mounted so as to protrude into the exhaust pipe having an inner diameter of 50 mm, and then propane gas was burned using a gas burner, and 2.5 m / sec. The combustion gas was injected at a flow rate of. At this time, the excess air ratio λ was set to 0.95 for 0 to 2 seconds after the start of gas burner injection, and after 2 seconds, the excess air ratio λ was switched to 1.05.
[0037]
The results of the response speed test are shown in FIGS. 5 to 8, the horizontal axis represents the combustion gas injection time by the gas burner, and the vertical axis represents the output value obtained by detecting the gas component. Here, the average output value from 0 to 2 seconds is represented as 0%, and the average output value from 18 seconds to 20 seconds is represented as 100%. And the transition to the output value of 100% is represented by a graph.
[0038]
FIG. 5 shows the response speed test result of Example 1, in which a taper portion 22 is formed by tapering the side wall of the inner cylindrical portion of the protector toward the bottom wall so that the outer diameter becomes smaller. When the outer angle at which the portion 22 intersects the bottom wall 17 is β °, and the axial tilt angle of the sensor for tilting the axial direction of the gas sensor with respect to the flow direction of the gas to be measured is α °, β ° is 60 °, the sensor axis Are tested for both 110 ° and 90 ° satisfying the relational expression of β ° ≦ (180 ° −α °).
[0039]
FIG. 6 shows the response speed test results of Example 2, where β ° is 60 °, and the installation angle α of the sensor shaft is both 120 ° and 90 ° satisfying the relational expression of β ° ≦ (180 ° −α °). This is a test.
FIG. 7 shows the response speed test results of Example 3, where β ° is 45 ° and the sensor shaft installation angle α is 120 ° and 90 ° satisfying the relational expression of β ° ≦ (180 ° −α °). This is a test.
[0040]
FIG. 8 shows the response speed test result of the comparative example. The side angle of the inner cylindrical portion of the protector is not tapered toward the bottom wall, and the sensor shaft installation angle α is 110 ° and 90 °. Both were tested.
In Examples 1 to 3, compared with the comparative example, the output value of the gas component with respect to the change in the combustion gas injection time by the gas burner is small and the response speed is good even if the installation angle α of the sensor shaft is changed. Results were obtained.
[0041]
Compared with the comparative example, in Example 1, when the installation angle α of the sensor shaft is both 90 ° and 110 °, the difference in the response speed for detecting the gas component of the gas to be measured is small and the detection accuracy is good. I understand.
Further, in the third embodiment, compared with the second embodiment, the difference in the response speed for detecting the gas component of the gas to be measured is small when the installation angle α of the sensor shaft is 90 ° and 120 °, and β ° is 60 It can be seen that 45 ° is preferable to °.
[0042]
Further, in order to confirm the operational effects of the present embodiment, the gas sensors having β ° of 60 ° and 45 ° used in Example 2 and Example 3 were used, and the gas was measured while sequentially changing the sensor shaft installation angle α °. The time until the output value of 50% of the components was detected was measured, and the result was shown as Example 4 and shown in FIG.
[0043]
As shown in FIG. 10, the time until the 50% gas component output value is detected is the output value when the horizontal axis represents the combustion gas injection time by the gas burner and the vertical axis represents the gas component detected output value. Is the response time ΔT when reaches 50%.
As shown in FIG. 9, when the protector has a taper angle β ° of 60 °, α ° is an obtuse angle, and in a range of 120 ° or less that satisfies the relational expression β ° ≦ (180 ° −α °). The 50% response time was 0.26 seconds or less, and it was found that a stable response speed was obtained with little change in the 50% response time with respect to the change in the sensor shaft installation angle α °.
[0044]
Further, when the protector has a taper angle β ° of 45 °, 50% response time is obtained when α ° is an obtuse angle and is 135 ° or less that satisfies the relational expression β ° ≦ (180 ° −α °). It was found that a stable response speed can be obtained with less change of 50% response time with respect to the change of the sensor shaft installation angle α ° in 0.26 seconds or less.
[0045]
Further, it was found that a protector having a taper angle β ° of 45 ° is more preferable because it is stable with less change in response time of 50% with respect to a change in sensor shaft installation angle than 60 °. .
The gas sensor mounting structure and method according to the embodiment having the above-described configuration, and the operation and effect of the gas sensor will be described below.
[0046]
According to the embodiment of the present invention, when the gas sensor is attached to the exhaust pipe, even if the sensor axis of the gas sensor is attached at an obtuse angle with respect to the flow direction of the gas to be measured, the measurement in the protector is performed. Gas replacement can be performed satisfactorily, and the responsiveness and detection accuracy for detecting the gas component of the gas to be measured can be improved.
[0047]
Further, according to the embodiment of the present invention, the gas to be measured introduced from the outer wall gas inlet and the gas to be measured which are detected and discharged from the outlet are not mixed in the protector. Therefore, it is possible to improve the response speed and the detection accuracy for detecting the gas component in the measured gas.
[0048]
Further, according to the embodiment of the present invention, the gas to be measured can be stably introduced into the inner cylindrical portion, the variation in the output value of the gas component is small, and the substitution of the gas to be measured in the protector is good. Thus, the response speed and the detection accuracy for detecting the gas component in the gas to be measured can be improved.
[0049]
According to the embodiment of the present invention, the shape of the discharge port 15 is a hole shape corresponding to the thickness of the bottom wall 17, but the discharge port 15 may be protruded outward by burring or the like. good.
Further, according to the embodiment of the present invention, the side wall 9 of the inner cylindrical portion 6 and the side wall 12 of the outer cylindrical portion 7 are formed in a substantially parallel shape, but the sensor shaft installation angle α ° and the taper β of the protector It may be formed in an inclined shape according to the installation conditions of °.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a gas sensor mounting structure to which the present invention is applied.
FIG. 2 is a cross-sectional view illustrating a configuration of a gas sensor according to an embodiment to which the invention is applied.
FIG. 3 is a half sectional view of an inner cylindrical portion in the gas sensor of the embodiment.
FIG. 4 is a half sectional view of an outer cylindrical portion in the gas sensor of the embodiment and a sectional view taken along the line BB in the drawing.
5 is a graph showing the response speed test results of Example 1. FIG.
6 is a diagram illustrating a response speed test result of Example 2. FIG.
7 is a diagram illustrating a response speed test result of Example 3. FIG.
FIG. 8 is a diagram illustrating a response speed test result of a comparative example.
FIG. 9 is a diagram illustrating a change in response time of 50% due to a change in sensor axis setting angle in the gas sensor mounting structure of the embodiment.
FIG. 10 is a diagram illustrating a change in 50% response time due to a change in sensor axis setting angle.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gas sensor, 2 ... Gas detection element, 3 ... Case, 4 ... Protector, 6 ... Inner cylindrical part, 7 ... Outer cylindrical part, 8 ... Air gap, 9, 12 ... Side wall, 10 ... Guide body, 11 ... Inner wall Gas inlet, 13 ... Outer wall gas inlet, 15 ... Discharge port, 16 ... Bottom wall of outer cylindrical part, 17 ... Bottom wall of inner cylindrical part, 22 ... Taper, 25 ... Insertion hole, 51 ... Lead frame, 52 ... Ceramic holder, 53 ... Talc powder, 54 ... Ceramic sleeve, 55 ... Outer tube, 56 ... Lead wire, 57 ... Ceramic separator, 58 ... Flange, 59 ... Grommet.

Claims (2)

Covering the gas contact portion that is in contact with the gas to be measured formed on the front end side of the gas detection element, forming an inlet for the gas to be measured on the side wall, and forming an outlet for the gas to be measured on the bottom wall. A gas sensor including a protector that is tapered at least on the tip side that is connected to the bottom wall and exposed to the outside so that the outer diameter becomes smaller toward the bottom wall. A gas sensor mounting structure that protrudes into the exhaust pipe and is attached to the gas sensor, wherein an outer angle at which the taper portion intersects the bottom wall is β °, and an axial inclination angle of the gas sensor that inclines the axial direction of the gas sensor with respect to the flow direction of the measured gas And α ° is an obtuse angle, 135 ° or less, and β ° is 45 ° or less, and is attached so as to satisfy the relational expression of β ° ≦ (180 ° −α °). Gassen Mounting structure Covering the gas contact portion that is in contact with the gas to be measured formed on the front end side of the gas detection element, forming an inlet for the gas to be measured on the side wall, and forming an outlet for the gas to be measured on the bottom wall. A gas sensor including a protector having a taper portion with a tapered outer diameter that is connected to at least the bottom wall and exposed to the outside, toward the bottom wall. A gas sensor mounting method for protruding and mounting in a pipe, wherein an outer angle at which the tapered portion intersects the bottom wall is β °, and an axial tilt angle of the gas sensor is tilted with respect to a flow direction of the gas to be measured. The gas sensor is mounted so as to satisfy a relational expression of β ° ≦ (180 ° −α °) when α ° is an obtuse angle, 135 ° or less, and β ° is 45 ° or less. Take Pasting method.

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