JP2012063165A - Method for confirming water penetration into protector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of confirming water penetration into a protector for surely grasping from which part of a protector has condensed water penetrated or the state of the condensed water which has penetrated into the protector.SOLUTION: Disclosed is a method of confirming water penetration into a protector 1 for scattering condensed water in an exhaust tube 55 by operating an engine 53, and for checking the state of the condensed water which penetrates into the protector 1. This method uses an observation device 59 in which an annular mending tool 67 for visualization device and an annular mending tool 69 for protector are connected so as to be attachable/detachable with their axial directions matched. This observation device 59 includes the protector 1, and a fiber scope 73 is inserted into the central hole of the observation device 59 so that the inside of the protector 1 can be observed. Then, the observation device 59 is arranged at the mounting position of a gas sensor 2 of the exhaust tube 55, and the state of the condensed water which penetrates into the protector 1 is observed by the fiber scope 73 by operating the engine 53.

Description

The present invention relates to a method for confirming water intrusion into a protector used for a sensor such as an O ₂ sensor or a NOx sensor, which is disposed in an exhaust pipe of a four-wheel or two-wheel vehicle.

  Conventionally, there has been provided a detecting element that generates electromotive force of different magnitude or changes its resistance value according to the concentration of a specific gas, such as oxygen or NOx (nitrogen oxide), in an exhaust gas such as an automobile. Gas sensors are known.

  In this type of gas sensor, a protector (which allows passage of exhaust gas) is attached so as to cover the periphery of the detection element in order to prevent water, poisonous substances and the like from directly hitting the detection element.

  By the way, when the engine is stopped or cold start, moisture contained in the exhaust gas is condensed (hereinafter referred to as condensed water), and the condensed water may adhere to the inner wall surface of the exhaust pipe. When the engine is normally started in this state, the condensed water adhering to the inner wall surface of the exhaust pipe is scattered by the vibration of the engine and the flow of exhaust gas. If the condensed water that has scattered struck the protector and then adhered to the heated detection element, the detection element may be cracked by thermal shock.

  As a countermeasure against this, a method for evaluating in advance whether or not the detection element is cracked by moisture before the gas sensor is attached to the exhaust pipe and used has been developed. As a test method for performing this evaluation, for example, there is a method in which a carbon element equipped with a protector is disposed at the mounting position of the gas sensor, and the wet state of the detection element is estimated based on the state of condensed water adhering to the carbon element. Known (see Patent Documents 1 and 2).

  In addition to this, in order to design a gas sensor that is not easily affected by condensed water, a device has been proposed in which a visualization device is attached at the gas sensor mounting position in the exhaust pipe to check the state of condensation water scattering. This apparatus uses a cylindrical transparent housing instead of a protector, inserts a fiberscope into the housing, and actually observes the state of the condensed water scattered with respect to the housing (Patent Document 3). reference).

JP 2006-234757 A JP 2008-28183A JP 2009-53128 A

  However, all of the condensed water that has entered the protector does not adhere to the carbon element, and the techniques of Patent Documents 1 and 2 described above have a problem that the state of intrusion of condensed water into the protector cannot be accurately grasped. It was. In particular, there is a problem that the state of the condensed water in the protector cannot be accurately grasped, such as where the condensed water has entered from the protector and how the condensed water that has entered the protector behaves.

  Further, in the technique of Patent Document 3 described above, the amount of condensed water flying to the gas sensor can be grasped, but since the actual protector is not attached to the exhaust pipe, the technique of Patent Documents 1 and 2 described above. As with, there is a problem that the state of the condensed water in the protector cannot be accurately grasped, such as where the condensed water enters from the protector and how the condensed water that has entered the protector behaves. there were.

For this reason, there has been a problem that it is difficult to take effective measures against condensed water entering the protector.
The present invention has been made in order to solve the above-mentioned problems, and into the protector that can reliably grasp where the condensed water has entered from the protector and the behavior of the condensed water that has entered the protector. The purpose is to provide a water intrusion confirmation method.

  (1) According to the present invention, as described in claim 1, the protector of the gas sensor is disposed in the exhaust pipe of the engine (for example, the mounting position of the gas sensor), the engine is operated to scatter water in the exhaust pipe, A method for confirming water intrusion into a protector for examining a state of water invading into the protector using a visualization device, the first through hole being axially inserted and inserted into the first through hole Using the annular visualization device jig for holding the visualization device, and an annular protector jig having a second through hole in the axial direction and to which the protector can be attached on the tip side, The protector is attached to the jig to prepare a jig with a protector, and the front end side of the visualization device is inserted into the second through hole so that the rear end side of the jig with the protector and the visualization device are used. Healing Assembly of a front end side to fit the axial direction, then, the protector is characterized in that attached to the exhaust pipe so as to be in contact with the exhaust gas in the exhaust pipe.

  In the present invention, the jig for the visualization device that holds the visualization device is assembled to the jig for the protector to which the protector can be attached, and the tip side of the visualization device is inserted into the second through hole of the jig for the protector. The protector is attached to the exhaust pipe. Thereby, when the engine is operated, it is possible to reliably grasp the state of the condensed water that enters the protector.

  In other words, in the present invention, an actual protector can be attached to the exhaust pipe, and the inside of the exhaust pipe can be confirmed with a visualization device. Therefore, it is possible to reliably capture the intrusion of condensed water into the protector, thereby reducing the risk of being exposed to water. It is possible to extract without leakage. In addition, the path of condensed water entering the protector and the behavior of the condensed water in the protector can be reliably detected, so that it becomes possible to develop a new and more preferable protector, and more preferable attachment of the gas sensor to the exhaust pipe. A layout can be obtained.

That is, according to the present invention, the intrusion state of the condensed water into the actual protector can be surely grasped, so that it is easy to take an effective measure against the condensed water.
(2) In the present invention, as described in claim 2, the protector jig is attached to a plurality of protectors of the same type or different types, and a plurality of jigs with protectors are produced. A specific number of jigs for a visualization device, which are fewer than the plurality of protectors, can be configured to be detachable from any protector-equipped jig.

  The method for confirming water intrusion into a protector of the present invention is often performed for the development of a new and more preferable protector. For this reason, a plurality of protectors of the same type or a plurality of different types (different types) of protectors are used. Often done. Then, it is necessary to prepare the number of the visualization device and the visualization device jig corresponding to the protector and the protector jig (the jig with the protector), respectively. If a plurality of devices are prepared, the apparatus becomes complicated and the cost increases.

  Therefore, in the present invention, when investigating (testing) the ingress state of condensed water with respect to a plurality of protectors of the same type or different types of protectors, respectively, with respect to a plurality of jigs with protectors, respectively. A specific number of jigs for a visualization device that are detachable and less than a plurality of protectors are prepared. In this way, for example, by changing a jig with a protector to a jig for a visualization apparatus that holds a single visualization apparatus, a test for a plurality of protectors can be performed with a single visualization apparatus and visualization. This can be performed using a device jig. Therefore, the apparatus used for the test can be simplified, which is advantageous in terms of cost.

  Note that “a specific number of jigs for a visualization device smaller than a plurality of protectors” means that, for example, when there are three protectors, there are one or two visualization device jigs. This means that the number of jigs is less than the number of protectors.

  (3) In the present invention, as described in claim 3, a first airtight member for preventing gas leakage between the jigs for the visualization device and the jig for the protector is disposed. Is preferred.

Thereby, the leak of the gas between the jig | tool for visualization apparatuses and the jig | tool for protectors can be prevented.
(4) In the present invention, as described in claim 4, between the visualization device and at least the visualization device jig and the protector jig, the second hermetic member prevents gas leakage between the two members. Is preferably arranged.

Thereby, the gas leakage between the visualization device and the visualization device jig or the protector jig can be prevented.
(5) In this invention, it is preferable that the front-end | tip of a visualization apparatus does not protrude from the attachment position of the protector in the jig | tool for protectors like Claim 5.

  As a result, the inside of the protector can be confirmed in a wide range (for example, viewing and photographing), and when the visualization device is inserted into the protector, the visualization device has an effect on the behavior of the condensed water in the protector. Can be resolved. Therefore, it is possible to accurately grasp the intrusion state of the condensed water into the protector.

  (6) In the present invention, as described in claim 6, as the protector, the inner cylindrical internal protector and the cylindrical external protector that covers the outer peripheral side of the internal protector are arranged concentrically. Heavy protector.

  If the protector has a double structure, the state of the condensate that enters the internal protector from the outside of the protector (the condensate intrusion path into the protector and the behavior of the condensate in the protector) is a single protector. Different. Therefore, it is difficult to confirm the state of the condensed water that enters the internal protector only by confirming the condensed water flying toward the external protector.

  However, in the present invention, by arranging the visualization device at a position where the inside of the internal protector can be confirmed, the state of the condensed water that enters the internal protector can be reliably grasped even with a double protector.

It is a fragmentary sectional view of the gas sensor provided with the protector of the observation object of an embodiment. It is explanatory drawing which shows the test apparatus used for the water penetration | invasion confirmation method in a protector. It is explanatory drawing which expands the AA cross section of FIG. 2, and shows the state which attached the observation apparatus to the exhaust pipe. It is explanatory drawing which shows the state which fractured | ruptured the observation apparatus along the axial direction. (A) is a plan view showing a protector jig, (b) is a front view showing a protector jig and a protector, (c) is a plan view showing a visualization device jig, and (d) is a visualization device treatment. The front view which shows a jig | tool with a tool and a protector, (e) is a front view which shows an observation apparatus main body. 6 is an explanatory diagram illustrating an experimental method of Experimental Example 1. FIG. It is explanatory drawing which shows another observation apparatus. (A) is a front view showing another jig for protector and protector, (b) is a front view showing another jig for visualization device and jig with protector, and (c) is a front view showing another observation device main body. FIG.

Hereinafter, an embodiment of a method for confirming water intrusion into a protector to which the present invention is applied will be described with reference to the drawings.
[Embodiment]
a) First, a brief description will be given of a gas sensor including a protector that is an object of the method for confirming water intrusion into the protector according to the present embodiment.

  As shown in FIG. 1, in this embodiment, a gas sensor 2 including a protector 1 that is a target of a method for confirming water intrusion into a protector is, for example, a so-called full-range air-fuel ratio sensor that detects an air-fuel ratio of automobile exhaust gas. It is.

  The gas sensor 2 includes a cylindrical metal shell 5 formed with a screw portion 3 for fixing to an exhaust pipe, a plate-shaped detection element 7 extending in the axial direction (vertical direction in the drawing), A cylindrical ceramic sleeve 9 disposed so as to surround the periphery in the radial direction, an insulating contact member 11 disposed so as to surround the rear end portion of the detection element 7, and the detection element 7 and the insulating contact member 11. And a plurality of connection terminals 13 disposed therebetween.

  Among these elements, the detection element 7 is formed by laminating a plate-shaped element portion 15 extending in the axial direction and a plate-shaped heater 17 that also extends in the axial direction, and is a tip directed toward the gas to be measured. On the side, a detection unit 21 covered with the porous layer 19 is formed.

  The metal shell 5 has a substantially cylindrical shape, and includes a through hole 23 that penetrates in the axial direction and a shelf portion 25 that projects inward in the radial direction of the through hole 23. The metal shell 5 is configured to hold the detection element 7 in a state where the detection portion 21 is disposed outside the front end side of the through hole 23 and the plurality of electrode terminal portions 27 are disposed outside the rear end side of the through hole 23. ing. A ceramic holder 29, powder filling layers 31 and 33, and a ceramic sleeve 9 are disposed inside the through hole 23 of the metal shell 5.

  Further, on the outer periphery of the distal end portion 35 of the metal shell 5, the metal double protector 1 covering the protruding portion of the detection element 7, that is, a cylindrical outer protector 39 and an inner protector 41 arranged concentrically. The protector 1 which consists of is attached by welding etc.

  Furthermore, an outer cylinder 43 is fixed to the outer periphery of the rear end side of the metal shell 5, and a holding member 45 that holds the insulating contact member 11 is fixed to the inner side of the outer cylinder 43. A grommet 47 is disposed in the opening on the rear end side of the outer cylinder 43, and a plurality of lead wires 49 connected to the electrode terminal portions 27 of the detection element 7 are inserted into the grommet 47.

b) Next, the overall configuration of the apparatus used in the method for confirming water intrusion into the protector according to the present embodiment will be described with reference to FIGS.
As shown in FIG. 2, the test apparatus 51 used in the method for confirming water intrusion into the protector is a regular port 57 of an exhaust pipe 55 of an engine 53 used in an automobile or the like, that is, normally empty during operation of the engine 53. An observation device 59 is attached to a port to which the gas sensor 2 for detecting the fuel ratio is attached.

  As shown in FIG. 3, the regular port 57 surrounds a circular through hole 61 formed on one end side in the radial direction of the cylindrical exhaust pipe 55 (upward in FIG. 3) and the periphery of the through hole 61. And an annular observation device mounting portion 63 joined to the outer peripheral side of the exhaust pipe 55.

  A screw portion 65 is formed on the inner peripheral surface of the observation device mounting portion 63. As will be described in detail later, the protector 1 is attached to the exhaust pipe 55 by screwing the observation device 59 to the screw portion 65. The observation device 59 can be attached vertically to the exhaust pipe 55 in a state of protruding inward.

c) Next, the observation device 59 which is a main part of the present embodiment will be described in detail.
(1) Configuration of Observation Device 59 As shown in FIG. 4, the observation device 59 is configured by coaxially coupling a cylindrical visualization device jig 67, a cylindrical protector jig 69, and the cylindrical protector 1. The observation device main body 71 is provided, and a fiberscope 73 (corresponding to the visualization device in the claims) is attached to the axial center of the observation device main body 71.

  Among them, the visualization device jig 67 is formed by, for example, connecting a cylindrical front end fitting 75 made of stainless steel and a cylindrical rear end fitting 77 made of stainless steel, for example, coaxially, and this. Between the front end fitting 75 and the rear end fitting 77, for example, an annular elastic packing 79 (corresponding to a second hermetic member in claims) made of fluororubber is disposed.

  The front end fitting 75 includes a front end portion 80 and a rear end portion 81 having a larger outer diameter (on the rear end side), and the rear end side of the outer periphery of the rear end portion 81 has a hexagonal shape. . A threaded portion 83 for coupling with the protector jig 69 is formed on the outer peripheral surface of the distal end portion 80.

  A center hole 85 is formed at the axial center of the tip fitting 75, and the center hole 85 has a center hole tip 87 having an inner diameter slightly larger than the outer diameter of the fiber scope 73 and an inner diameter larger than that ( And a rear end 89 of the center hole (on the rear end side).

  On the inner peripheral surface of the rear end side of the center hole rear end portion 89, a screw portion 91 for connecting the front end fitting 75 and the rear end fitting 77 is formed. The packing 79 is disposed on the front end side of the center hole rear end portion 89.

  On the other hand, the rear end metal fitting 77 is also composed of a front end portion 93 and a rear end portion 95 having a larger outer diameter (on the rear end side), and the outer periphery of the rear end portion 95 has a hexagonal shape. A central hole 97 having an inner diameter slightly larger than the outer diameter of the fiber scope 73 is formed at the axial center of the rear end fitting 77. Further, on the outer peripheral surface of the front end portion 93, a screw portion 99 for connecting the front end metal fitting 75 and the rear end metal fitting 77 is formed.

The center hole 85 of the front end fitting 75 and the center hole 97 of the rear end fitting 77 constitute the first through hole 100 of the visualization device jig 67.
Further, the protector jig 69 has a distal end portion 101 to which the protector 1 is externally fitted and joined from the distal end side, an outer diameter larger than the distal end portion 101, and an exhaust pipe 55 on the outer periphery thereof (with the observation device 59). And a rear end 107 having a larger outer diameter than that of the central portion 105.

  Further, a center hole (second through hole) 109 is formed at the axial center of the protector jig 69, and the center hole 109 has a center hole tip 111 having an inner diameter slightly smaller than the outer diameter of the fiber scope 73. And a center hole central part 113 having a larger inner diameter (on the rear end side) than the center hole front end part 111 and a center hole rear end part 115 having a larger inner diameter than the center hole central part 113 (on the rear end side). Yes. The inner diameters of the center hole central portion 113 and the center hole rear end portion 115 are larger than the outer diameter of the fiber scope 73.

On the inner peripheral surface of the central hole rear end portion 115, a screw portion 117 for connecting the photographing jig 67 and the protector jig 69 is formed.
The first through hole 100 and the second through hole 109 constitute a coupling through hole 118 into which the fiberscope 73 is inserted, and the protector jig 69 and the protector 1 constitute a protector-equipped jig 120. Yes.

  Further, between the visualization device jig 67 and the protector jig 69, more specifically, between the rear end surface of the rear end portion 107 of the protector jig 69 and the front end surface of the rear end portion 81 of the photographing jig 67. In the meantime, an annular packing 119 (corresponding to the first hermetic member in the claims) made of, for example, stainless steel is disposed so as to be externally fitted to the tip 79 of the photographing jig 67.

  The fiberscope 73 is inserted into the coupling through hole 118 at the axial center of the observation apparatus main body 71, that is, the center hole 97 of the rear end metal fitting 77, the center hole front end portion 87 of the front end metal fitting 45, and the protector. It arrange | positions so that the center hole center part 113 of the jig | tool 69 may be penetrated.

  The distal end of the fiberscope 73 is positioned in contact with the stepped portion 121 between the central hole distal end portion 111 and the central hole central portion 113 of the protector jig 69, and the distal end is a joining portion of the protector 1. It is arranged on the rear end side.

Therefore, an image inside the protector 1 (specifically, inside the internal protector 41) can be obtained from the fiberscope 73.
The protector 1 has a double structure similar to that attached to the gas sensor 2, and the side walls of the external protector 39 and the internal protector 41 can pass exhaust gas. A plurality of vent holes 40 and 42 are formed. A tip hole 44 for exhaust and drainage is formed at the tip of the internal protector 41.

(2) Assembling method of the observation device 59 When assembling the observation device 59, first, as shown in FIG. 5 (b), the protector 1 is externally fitted on the tip 101 of the protector jig 69, and the periphery thereof is It joins by welding (for example, laser welding). Thereby, the jig | tool 120 with a protector is produced.

  Specifically, since the protector 1 has a double structure of the external protector 39 and the internal protector 41, the internal protector 41 is first fitted on the tip 101 of the protector jig 69, and then the external protector is placed outside the internal protector 41. 39 is fitted and the external protector 39 and the internal protector 41 are joined to the front-end | tip part 101 by welding.

  Next, as shown in FIG. 4, the packing 79 is disposed at the center hole rear end portion 89 of the front end fitting 75, and the screw portion 99 of the rear end fitting 77 is partially screwed to the screw portion 91 of the front end fitting 75. Thus, the visualization device jig 67 is produced.

  Next, as shown in FIG. 5 (d), the tip portion of the tip fitting 75 of the visualization device jig 67 with the packing 119 sandwiched between the visualization device jig 67 and the protector-equipped jig 120. The screw portion 83 of 79 and the screw portion 117 of the rear end portion 107 of the jig 120 with protector are screwed together, and the visualization device jig 67 and the jig 120 with protector are fixed together. As a result, an observation apparatus main body 71 as shown in FIG.

Next, as shown in FIG. 4, the fiberscope 73 is inserted into the coupling through hole 118 at the axial center from the rear end side of the observation apparatus main body 71 and brought into contact with the stepped portion 121 described above.
Thereafter, the rear end fitting 77 is strongly screwed into the front end fitting 75, thereby fixing the visualization device jig 67 (therefore, the observation device main body 71) and the fiberscope 73 together.

  That is, as the rear end fitting 77 is screwed into the front end fitting 75, the packing 79 is crushed and spreads in the plane direction, and the fiberscope 73 is pressed from the outer peripheral side, whereby the fiberscope 73 is made into the visualization device jig 67. Fix it.

(3) Attachment method of the observation device 59 When the observation device 59 is attached to the exhaust pipe 55, the observation device 59 is screwed to the regular port 57 as shown in FIG.

  Specifically, an annular packing 125 made of, for example, stainless steel is fitted into the central portion 105 of the tip fitting 69 of the observation device 59, and the screw portion 103 of the central portion 105 is screwed into the screw portion 65 of the observation device attachment portion 63. .

As a result, the observation device 59 can be attached vertically to the exhaust pipe 55 with the protector 1 protruding into the exhaust pipe 55.
At the rear end of the fiberscope 73 of the observation device 59, although not shown, a CCD camera that captures light information from the fiberscope 73, a monitor that displays the captured information (image), and a video that records information (image). Connect the device.

Further, although not shown, the observation device 59 may be provided with a heater that prevents the tip surface of the fiberscope 73 from condensing, a light that illuminates the inside of the protector 1, and the like.
d) Next, an experimental procedure of a method for confirming water intrusion into the protector will be described.

(1) Experimental example 1 (Confirmation method using one type of protector)
As shown in FIG. 6, with the observation device 59 attached to the regular port 57 of the exhaust pipe 55, the engine 53, the cooling water of the engine 53, and the exhaust pipe 55 are exposed to a temperature lower than the dew point, for example. The gas sensor 2 used for controlling the engine 53 may be attached to a location different from the regular port 57 (for example, downstream of the regular port 57).

Thereafter, the engine 53 is operated at least once (here, a plurality of times) for a predetermined time (for example, a total of 2 minutes) to generate condensed water in the exhaust pipe 55.
Thereafter, the generated condensed water is blown downstream by exhaust gas scavenging (racing), and the state of the condensed water entering the protector 1 at that time is confirmed by the observation device 59.

  Since the field of view of the fiberscope 73 is a range that extends from the tip of the fiberscope 73 in a conical shape (axis center: 60 ° angle from the optical axis), the image obtained by the fiberscope 73 contains the inside of the protector 1. The entire image (specifically, the entire interior of the internal protector 41) is included.

(2) Experiment 2 (Confirmation method using other types of protectors)
After examining the intrusion state of the condensed water in the protector 1 according to the experimental example 1, as shown in FIGS. 7 and 8, another observation device 133 including the protector 131 having another structure is used according to the experimental example 2. Repeat the same experiment.

  In the observation device 133 of this experimental example 2, the structure of the protector 131 (and hence the jig 135 with the protector) is different from that of the observation device 59 of the experimental example 2, but other components (the visualization device jig 67, The fiberscope 73 and the like are the same as the observation device 59 of the experimental example 1.

  The shape of the protector jig 137 is the same as that of Experimental Example 1, but the product itself is different because the protector 131 having another structure is joined thereto. Accordingly, the protector jig 137 can be used for the experiment example 1 and can be coupled to the visualization apparatus jig 67 by screws.

In Experimental Example 2, a protector 131 having another structure is joined in advance to a protector jig 137 having a structure similar to that in Experimental Example 1 to prepare a protector-equipped jig 135.
Then, after the experimental example 1, the observation device 59 is removed from the exhaust pipe 55, and in the observation device 59, the screw connection between the visualization device jig 67 and the protector jig 69 (and hence the jig 135 with the protector) is performed. The visualization device jig 67 and the protector-equipped jig 135 are separated by loosening. At this time, the fiberscope 73 remains fixed to the visualization device jig 67.

Thereafter, a new observation device 133 is configured by screwing the protector-equipped jig 135 with the other structure onto the visualization device jig 67.
Therefore, the new observation device 133 can be attached to the exhaust pipe 55, and the intrusion confirmation of the condensed water into the protector 131 can be performed in the same manner as in Experimental Example 1 described above.

  e) As described above, in this embodiment, the visualization device jig 67 for holding the visualization device (fiberscope 73) is assembled to the protector jig 69 to which the protector 1 can be attached, and the distal end side of the fiberscope 73 is attached. Is inserted into the second through-hole 109 of the protector jig 69 to attach the protector 1 to the exhaust pipe 55. Thereby, when the engine 53 is operated, the state of the condensed water that enters the protector 1 can be reliably grasped.

  In other words, since the actual protector 1 can be attached to the exhaust pipe 55 and the inside thereof can be confirmed with the fiberscope 73, it is possible to reliably capture the intrusion of condensed water into the protector 1, thereby reducing the risk of being exposed to water. It is possible to extract without leakage. Further, since the intrusion path of the condensed water into the protector 1 and the behavior of the condensed water within the protector 1 can be reliably detected, a new and more preferable protector 1 can be developed, and the exhaust pipe 55 of the gas sensor 2 can be developed. A more preferable mounting layout can be obtained.

  Moreover, in this embodiment, when examining the invasion state of condensed water with respect to a plurality of protectors 1 of the same type or different types of protectors 131, respectively, with respect to a plurality of jigs 120 and 135 with protectors, respectively. A specific number of visualization device jigs 67 that are detachable and less than the plurality of protectors 1 are prepared. In this way, the test for a plurality of protectors 1 and 131 can be performed by changing the jigs 120 and 135 with protectors to a single visualization device jig 67 (with the fiberscope 73 attached). A single fiberscope 73 and a visualization device jig 67 can be used. Therefore, the apparatus used for the test can be simplified, which is advantageous in terms of cost.

  Furthermore, in the present embodiment, a packing 119 for preventing gas leakage between the jigs 67 for the visualization device and the jig 69 for the protector is disposed. Thereby, the leak of the gas between the jig | tool 67 for visualization apparatuses and the jig | tool 69 for protectors can be prevented.

  In addition, in the present embodiment, a packing 79 that prevents gas leakage between the two members is disposed between the fiberscope 73 and the observation apparatus main body 71. Thereby, the gas leak between the fiberscope 73 and the observation apparatus main body 71 can be prevented.

  In this embodiment, the attachment position of the fiberscope 73 is set so that the tip of the fiberscope 73 does not protrude from the attachment position of the protector 1 in the protector jig 69. As a result, the inside of the protector 1 can be confirmed in a wide range (for example, photographing), and when the fiberscope 73 is inserted into the protector 1, the fiberscope 73 affects the behavior of the condensed water in the protector 1. Can solve the problem. Therefore, the intrusion state of the condensed water into the protector 1 can be accurately grasped.

  Furthermore, in the present embodiment, a double protector arranged concentrically is used as the protector 1. When the protector 1 has a double structure, the state of condensed water entering the internal protector 41 from the outside of the protector 1 is different from that of the single protector. Therefore, it is difficult to confirm the state of the condensed water that enters the internal protector 41 only by confirming the condensed water flying toward the external protector 39. However, in this embodiment, by arranging the fiberscope 73 at a position where the inside of the internal protector 41 can be confirmed, the state of the condensed water that enters the internal protector 41 can be reliably grasped.

As mentioned above, although embodiment etc. of this invention were described, this invention is not limited to the said embodiment etc., A various aspect can be taken.
(1) For example, the present invention can be applied not only to a full-range air-fuel ratio sensor but also to other oxygen sensors, NOx sensors, HC sensors, or the like.

  (2) In the above embodiment, the plate-shaped detection element integrated with the heater has been described. However, the present invention can be applied to a case of a bottomed cylindrical detection element separately provided with a heater. Applicable.

DESCRIPTION OF SYMBOLS 1,131 ... Protector 2 ... Gas sensor 51 ... Test device 53 ... Engine 55 ... Exhaust pipe 57 ... Regular port 59, 133 ... Observation device 71 ... Observation device main body 73 ... Fiberscope 67 ... Visualization device jig 69, 137 ... Protector Jig 79 ... Packing (second airtight member)
DESCRIPTION OF SYMBOLS 100 ... 1st through-hole 109 ... 2nd through-hole 118 ... Coupling through-hole 119 ... Packing (1st airtight member)
120, 135 ... Jig with protector

Claims (6)

A gas sensor protector is arranged in the exhaust pipe of the engine, the engine is operated to scatter water in the exhaust pipe, and the state of the water entering the protector is examined using a visualization device. Water intrusion into the protector Check method,
An annular visualization device jig having a first through hole in the axial direction and holding the visualization device inserted through the first through hole;
An annular protector jig that has a second through hole in the axial direction and can be attached to the protector on the tip side,
The protector is attached to the protector jig to produce a protector-attached jig, and the rear end side of the protector-attached jig is inserted into the second through hole so that the tip side of the visualization device is inserted. And the tip side of the jig for the visualization device are assembled with the axial direction aligned,
Thereafter, the protector is attached to the exhaust pipe so as to be in contact with the exhaust gas in the exhaust pipe.   The protector jig is attached to each of the plurality of protectors of the same type or different types to produce a plurality of jigs with protectors, and a smaller number of jigs for the visualization device than the plurality of protectors. The method for confirming water intrusion into a protector according to claim 1, wherein a tool can be attached to and detached from any of the jigs with protectors.   The inside of the protector according to claim 1 or 2, wherein a first airtight member for preventing gas leakage between the two jigs is disposed between the visualization device jig and the protector jig. To confirm water intrusion into the water.   A second airtight member for preventing gas leakage between the two members is disposed between the visualization device and at least the visualization device jig and the protector jig. The method for confirming water intrusion into the protector according to any one of the above.   The method for confirming water intrusion into a protector according to any one of claims 1 to 4, wherein a tip of the visualization device does not protrude from an attachment position of the protector in the protector jig.   The said protector is a double protector which arrange | positioned the cylindrical internal protector inside and the cylindrical external protector which covers the outer peripheral side of this protector concentrically. The method for confirming water intrusion into the protector according to claim 1.