JP5545451B2 - Exhaust gas measuring device - Google Patents

Description

  The present invention relates to an exhaust gas measuring device that detects the concentration of carbon monoxide or the like contained in exhaust gas from combustion equipment.

  A combustion device such as a boiler or a water heater may be provided with a CO sensor that monitors the concentration of carbon monoxide in exhaust gas. In this case, a catalytic combustion type CO sensor is often used from the viewpoint of cost.

  However, this type of CO sensor is susceptible to dew condensation in addition to the exhaust gas flow velocity and temperature. Specifically, if the flow rate of exhaust gas is high, it may cause failure or error. Moreover, even if the temperature of the exhaust gas is high, it may cause failure or error. Furthermore, even if moisture adheres to the sensor, it may cause a failure or an error.

  Among these, in order to prevent the influence of the flow velocity, as disclosed in Patent Document 1 below, a CO detection mechanism (3) is conventionally disposed in a cover (35) that opens in a direction perpendicular to the flow of exhaust gas. In addition, it has been proposed to provide a flow rate reducing member (40) such as a mesh at the opening of the cover (35), decelerate the exhaust gas and introduce it into the cover (35) to detect the CO concentration.

  However, even if the influence of the flow velocity can be removed to some extent, it does not solve the influence of the exhaust gas temperature or the influence of condensation.

Japanese Patent Laid-Open No. 9-5278 (paragraph numbers 0024-0025, FIG. 1)

  The problem to be solved by the present invention is that the concentration of carbon monoxide or the like can be detected more accurately by preventing the sensor from malfunctioning or measuring errors due to the flow rate or temperature of the exhaust gas or condensation. The object is to provide an exhaust gas measuring device.

  In addition, the influence of failure and measurement error due to flow velocity, temperature, condensation can occur not only in catalytic combustion type CO sensors, but also in other types of CO sensors, and is not limited to carbon monoxide, It can also occur in sensors that measure other components. Therefore, not only the contact combustion type CO sensor but also various types of sensors have similar problems to be solved.

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is provided to extend obliquely upward on the wall of the exhaust gas passage from the combustion equipment, and for the exhaust gas passing through the exhaust gas passage. A part is taken out through the take-out path, folded at the end of the take-out path, and installed in an extraction pipe returning to the exhaust gas path through the return path, and an upward recess provided in the return path, An exhaust gas sensor that detects the concentration of carbon monoxide, carbon dioxide, oxygen, or nitrogen oxide in the exhaust gas, and the extraction pipe is an outer pipe having a rectangular cross section and a rectangular cross section that is fitted into the lower half of the cross section of the outer pipe The outer pipe is provided such that one end is closed by an end wall and the other end is opened to the exhaust gas path, and the inner pipe has one end connected to the end wall. By being spaced apart A return opening is formed, or one end is closed and a folded opening is formed on the upper wall on the one end side, while the other end extends beyond the outer pipe and opens to the exhaust gas passage. The outer pipe is provided with a concave portion on the upper wall on the downstream side of the folding opening, the upper portion of the concave portion is closed, and the exhaust gas sensor is provided in the concave portion. Is an exhaust gas measuring device characterized by

According to the first aspect of the present invention, the exhaust gas sensor is disposed in the upward recess provided in the exhaust gas return path, not the flow path (extraction path, return path) of the extraction pipe through which the exhaust gas passes. By preventing the exhaust gas flow from directly hitting the exhaust gas sensor, it is possible to prevent failure due to the flow velocity and measurement errors. Moreover, since the extraction pipe provided with the exhaust gas sensor is provided so as to extend outward from the wall of the exhaust gas passage, the influence of the temperature on the exhaust gas sensor can be prevented. Further, the extraction pipe provided with the exhaust gas sensor is provided so as to extend obliquely upward from the wall of the exhaust gas path, and the exhaust gas sensor is disposed in the upward recess provided in the return path of the extraction pipe. It is possible to prevent the dew condensation water from staying inside, prevent the exhaust gas flow path from being blocked, and prevent the exhaust gas sensor from being flooded.

According to the first aspect of the present invention, the exhaust gas measuring device can be manufactured with a simple, inexpensive and stable quality by adopting a double tube structure of the outer pipe and the inner pipe.

The invention according to claim 2 is the exhaust gas measuring device according to claim 1 , wherein the inner pipe is provided with a tip portion thereof penetrating into the exhaust gas passage.

According to the invention described in claim 2 , by providing the tip of the inner pipe so as to enter the exhaust gas path, the influence of the boundary layer generated on the wall surface of the exhaust gas path is prevented, and the exhaust gas is stably measured. Can be passed through the device.

The invention according to claim 3 is characterized in that the inner pipe and the outer pipe are provided at an angle of 30 degrees or more with respect to a horizontal state and inclined upward as they are separated from the wall of the exhaust gas passage. An exhaust gas measuring device according to claim 1 or claim 2 .

According to invention of Claim 3 , it can prevent reliably that a water drop remains in a pipe by surface tension by hold | maintaining an extraction pipe at an angle of 30 degree | times or more with respect to a horizontal state.

Invention of claim 4, against the exhaust gas passing through the exhaust gas channel, switching port for guiding a part of exhaust gas into said pipe, characterized in that provided on the other end of the pipe according The exhaust gas measuring device according to any one of Items 1 to 3 .

According to the invention described in claim 4 , by providing the switching port at the end of the inner pipe, it is possible to smoothly introduce the exhaust gas from the exhaust gas passage to the inner pipe.

Furthermore, the invention according to claim 5 is the exhaust gas measuring device according to claim 4 , wherein the switching port has a shape in which the exhaust gas path corresponds to both a vertical direction and a horizontal direction.

According to the fifth aspect of the present invention, a common exhaust gas measuring device can be used regardless of whether the exhaust gas passage is in the vertical direction or in the horizontal direction.

  According to the present invention, it is possible to prevent a sensor from malfunctioning or causing a measurement error due to the flow rate or temperature of exhaust gas or condensation.

It is the schematic which shows one Example of the exhaust gas measuring apparatus of this invention, and is a longitudinal cross-sectional view which shows a use condition. It is a perspective view of the exhaust gas measuring device of FIG. It is a perspective sectional view of the exhaust gas measuring device of FIG. It is a schematic front view which shows the state which installed the exhaust gas measuring apparatus of FIG. 1 in the horizontal exhaust pipe. It is VV sectional drawing in FIG.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
1 to 3 are schematic views showing an embodiment of the exhaust gas measuring apparatus of the present invention. FIG. 1 is a longitudinal sectional view showing a use state, FIG. 2 is a perspective view, and FIG. 3 is a perspective sectional view.

  The exhaust gas measuring device 1 of the present embodiment is attached to the exhaust gas passage (exhaust tube 2) from the combustion equipment in an inclined state. Combustion equipment is equipment which burns fuels, such as oil and gas, and the kind in particular is not ask | required, but is typically boiler 3 (Drawing 4) or a water heater. Exhaust gas from the combustion equipment is discharged to the outside through the exhaust gas passage. The exhaust gas path is typically constituted by an exhaust pipe 2 having a circular cross section or a rectangular cross section, that is, a flue or chimney. In order to detect the concentration of carbon monoxide, carbon dioxide, oxygen or nitrogen oxide in the exhaust gas, the exhaust gas measuring device 1 is attached to the exhaust pipe 2.

  The exhaust gas measuring device 1 includes an extraction pipe 4 provided to extend outward from a peripheral side wall of the exhaust tube 2 and an exhaust gas sensor 5 provided on the extraction pipe 4. The extraction pipe 4 is provided so as to be inclined upward as it is separated from the peripheral side wall of the exhaust pipe 2. In FIG. 1, the extraction pipe 4 is usually arranged in the radial direction of the exhaust pipe 2 in a plan view of the exhaust pipe 2 extending vertically. In the extraction pipe 4, one end portion on the side that extends obliquely upward from the peripheral side wall of the exhaust tube 2 is referred to as a base end portion, and the other end portion on the side opened in the exhaust tube 2 is referred to as a tip portion. To do.

  The extraction pipe 4 is configured such that a part of the exhaust gas passing through the exhaust pipe 2 is taken out via the take-out path 6, folded back at the end of the take-out path 6, and returned to the exhaust pipe 2 through the return path 7. . Further, the exhaust gas sensor 5 is installed in an upward recess 8 provided in the return path 7 and detects the concentration of carbon monoxide, carbon dioxide, oxygen or nitrogen oxide in the exhaust gas. Of course, the exhaust gas sensor 5 may be capable of detecting a plurality of carbon monoxide, carbon dioxide, oxygen, and nitrogen oxide, or may be installed in the recess 8. Good.

  The extraction pipe 4 will be described in more detail. The extraction pipe 4 according to the present embodiment includes an outer pipe 9 having a rectangular cross section and an inner pipe 10 having a rectangular cross section that is fitted into the lower half of the cross section of the outer pipe 9. . The outer pipe 9 is closed at the base end portion by the end wall 11, while the distal end portion is opened. On the other hand, the inner pipe 10 has a base end portion that is spaced apart from the end wall 11, thereby forming a folded opening 12 between the base end portion of the inner pipe 10 and the end wall 11 of the outer pipe 9. Alternatively, instead of the base end being closed by an end wall (which may be the end wall 11 of the outer pipe 9), a folded opening is formed in the upper wall 13 (the wall on the return path 7 side) on the base end side. The Further, the inner pipe 10 is provided so as to extend sufficiently more than the front end portion of the outer pipe 9, and the front end portion is opened. The extent to which the inner pipe 10 is extended should be determined in consideration of the influence of the boundary layer of the exhaust gas flowing in the exhaust tube 2 as will be described later.

  The size of the folding opening 12 is appropriately set. In the case of the present embodiment, the flow path cross-sectional area of the take-out path 6 (cross-sectional area perpendicular to the axis of the inner pipe 10) and the flow path cross-sectional area of the return path 7 are set. Smaller than (the cross-sectional area of the upper half of the cross section perpendicular to the axis of the outer pipe 9 that is not fitted in the inner pipe 10), for example, about 1/2 to 1/4 of the flow path cross-sectional area. The size is set. More specifically, in this embodiment, the outer pipe 9 is a rectangular cross-section pipe having an outer dimension of 22 mm wide × 22 mm high and an inner dimension of 20 mm wide × 20 mm high. Is a pipe having a rectangular cross section with a width of 19 mm × height of 10 mm and an inner size of 17 mm × height of 8 mm. The gap between the base end surface of the inner pipe 10 and the end wall 11 of the outer pipe 9 is 2.5 mm to 3 mm. is there. However, these dimensions are merely examples, and needless to say, they can be changed as appropriate.

  With such a configuration, if the tip ends of the outer pipe 9 and the inner pipe 10 are opened into the exhaust tube 2, the inside of the inner pipe 10 is inside the take-out path 6, the outer pipe 9 and outside the inner pipe 10. Functions as the return path 7. That is, the exhaust gas in the exhaust pipe 2 is introduced from the distal end portion of the inner pipe 10, moves from the distal end portion of the inner pipe 10 to the proximal end portion, and is led out from the folding opening 12 to the outer pipe 9 outside the inner pipe 10, The outer pipe 9 moves from the proximal end portion to the distal end portion, and is returned from the distal end portion of the outer pipe 9 into the exhaust pipe 2.

  By the way, the upper wall 14 of the outer pipe 9 is provided with an upward concave portion 8 on the downstream side of the folding opening 12. How much downstream the recessed opening 8 is provided from the folding opening 12 is appropriately set. For example, the recessed part 8 is provided at or immediately after the pressure recovery point after rapid contraction and rapid expansion of the flow path by the folding opening 12. .

  In order to form the recess 8 in the extraction pipe 4, a sensor mounting cylinder 15 is used in this embodiment. The sensor mounting cylinder 15 has a cylindrical shape or a rectangular tube shape, and includes flanges (a lower flange 16 and an upper flange 17) at both axial ends. In the sensor mounting cylinder 15, the lower flange 16 is fixed to the upper wall 14 of the outer pipe 9 in an airtight state. The upper wall 14 of the outer pipe 9 is previously drilled at a position corresponding to the hollow hole of the sensor mounting cylinder 15. In this manner, an upward recess 8 is provided in the exhaust gas return path 7. The recess 8 is usually provided perpendicular to the upper wall 14 of the outer pipe 9. That is, the axis of the sensor mounting cylinder 15 is normally arranged perpendicular to the axis of the outer pipe 9. As will be described later, the upper opening of the hollow hole of the concave portion 8 is closed, and the exhaust gas sensor 5 is provided downward in the upper portion of the closed space (the concave portion 8) configured as described above.

  An exhaust gas sensor 5 (for example, a contact combustion type CO sensor) is provided in the concave portion 8 formed by a hollow hole of the sensor mounting cylinder 15. In the present embodiment, the exhaust gas sensor 5 is formed by providing a flange 19 at the upper end of the cylindrical main body 18. Therefore, in the exhaust gas sensor 5, the main body 18 is inserted into the hollow hole of the sensor mounting cylinder 15 from above, and the flange 19 is overlapped with the upper flange 17 of the sensor mounting cylinder 15 via the packing 20 and fixed with the screws 21. Is done. By sandwiching the packing 20 between both the flanges 17 and 19, the gap between both the flanges 17 and 19 is sealed, and the exhaust gas is prevented from escaping to the outside via the sensor mounting cylinder 15. When the exhaust gas sensor 5 is attached to the sensor mounting cylinder 15, the main body 18 of the exhaust gas sensor 5 is accommodated in the recess 8 without protruding into the outer pipe 9.

  As shown in FIG. 2, a substrate case 23 is provided at the base end portion of the extraction pipe 4 via an appropriate plate member 22, and a detection circuit (not shown) is accommodated in the substrate case 23. . The detection circuit is electrically connected to the exhaust gas sensor 5 and detects the concentration of carbon monoxide or the like. The plate 22 also functions as a heat shield that prevents heat from the extraction pipe 4 from being transmitted to the detection circuit.

  In FIG. 1, the state which attached the exhaust gas measuring apparatus 1 to the exhaust pipe 2 with the measurement port 24 as an exhaust gas path is shown. Specifically, the exhaust pipe 2 formed of a cylindrical body along the vertical direction is provided with a cylinder 25 protruding in the radial direction on the peripheral side wall in advance, and a flange 26 is provided at an end of the cylinder 25. A lid plate 27 is attached to the flange 26 in an airtight manner. The measuring port 24 thus configured is conventionally used for attaching a dust sensor or the like, but can also be used for attaching the exhaust gas measuring device 1 of the present embodiment. However, the exhaust gas measurement device 1 does not necessarily have to be attached to the measurement port 24 of the exhaust tube 2. Even if the measurement port 24 is not provided, an appropriate bracket is installed on the peripheral side wall of the exhaust tube 2, and the exhaust gas measurement device is similarly provided. 1 can be installed.

  The installation of the exhaust gas measuring device 1 on the lid plate 27 of the measurement port 24 will be described. The exhaust gas measuring device 1 is provided with a mounting plate 28 in advance. The mounting plate 28 is fixed to the distal end portion of the outer pipe 9 with the distal end portion of the outer pipe 9 being passed therethrough. At this time, the attachment plate 28 is provided so as to be vertically arranged in a state where the longitudinal axis of the extraction pipe 4 is inclined from the horizontal by the set angle α. As a result, as shown in FIG. 1, in the state where the attachment plate 28 is attached to the lid plate 27 of the measurement port 24 in an overlapping manner, the extraction pipe 4 is disposed in a state inclined by the set angle α from the horizontal. The inclination angle α is not particularly limited, but is preferably several tens of degrees and is preferably set to 30 degrees or more. In this embodiment, it is set to 30 degrees. When the exhaust gas measuring device 1 is used, the water droplets remain in the pipes 9 and 10 due to surface tension when the exhaust gas measuring device 1 is used by tilting upward as it is separated from the wall of the exhaust pipe 2 at an angle of 30 degrees or more with respect to the horizontal state Can be surely prevented. A packing 29 is interposed between the mounting plate 28 and the lid plate 27. Further, the mounting plate 28 has strength by bending the lower end portion.

  Thus, in a state where the exhaust gas measuring device 1 is installed in the measurement port 24 of the exhaust pipe 2, both the outer pipe 9 and the inner pipe 10 communicate with the exhaust pipe 2. In the illustrated example, the outer pipe 9 enters the exhaust cylinder 2 and is opened, and the inner pipe 10 is opened in the cylinder 25 of the measurement port 24.

  The outer pipe 9 and the inner pipe 10 are only required to communicate with the inside of the exhaust tube 2 and may be simply opened near the wall surface of the exhaust tube 2 or the measurement port 24. At least the inner pipe 10 It is preferable to provide the tip portion so as to enter the exhaust tube 2. This is for avoiding the influence of the boundary layer of the exhaust gas flowing in the exhaust tube 2. Therefore, the inner pipe 10 has only to enter deeper than the thickness of the boundary layer. For example, the inner pipe 10 is opened at the center of the exhaust pipe 2 or at a position 30 mm or more away from the inner surface of the exhaust pipe 2 and to the center of the exhaust pipe 2. The tip of the inner pipe 10 is preferably opened. In the case of the exhaust pipe 2 of a small once-through boiler, the diameter of the exhaust pipe 2 is typically about 90 to 400 mm.

  An appropriate switching port 30 may be provided at the tip of the inner pipe 10. The switching port 30 is for directing a part of the exhaust gas to the inner pipe 10 by hitting the exhaust gas passing through the exhaust pipe 2. The shape of the switching port 30 is not particularly limited. In the present embodiment, as shown in FIG. 2, the switching port 30 includes a first plate 31 and a second plate 32. In FIG. 2, the first plate 31 is a rectangular plate that is provided at the front end portion of the front wall 33 of the inner pipe 10 and that is inclined toward the front end side as it goes rearward. The second plate 32 is a trapezoidal plate provided so as to close the upper edge of the first plate 31 and the tip of the upper wall 13 of the inner pipe 10. Thereby, in FIG. 2, the front-end | tip part of the inner pipe 10 opens only back and downward.

  Because of such a configuration, as shown in FIG. 3, a part of the exhaust gas flowing upward through the exhaust tube 2 hits the second plate 32 of the switching port 30, so that the inside of the inner pipe 10 (the extraction path 6). Led to. Then, it is led to the outer pipe 9 (return path 7) through the folding opening 12 at the end of the inner pipe 10, and is returned to the exhaust pipe 2 from the tip of the outer pipe 9. During this time, the concentration of carbon monoxide or the like is accurately detected by the exhaust gas sensor 5 provided in the recess 8 of the return path 7.

  According to the exhaust gas measuring apparatus 1 of the present embodiment, not the flow path (extraction path 6 and return path 7) itself of the extraction pipe 4 through which the exhaust gas passes but the upward recess 8 provided in the exhaust gas return path 7. Since the exhaust gas sensor 5 is installed upside down, it is possible to prevent the exhaust gas flow from directly hitting the exhaust gas sensor 5 and to prevent failure due to the flow velocity and measurement errors.

  Further, since the extraction pipe 4 provided with the exhaust gas sensor 5 is provided to extend outward from the wall of the exhaust cylinder 2, the influence of the temperature on the exhaust gas sensor 5 can be prevented. Moreover, the influence of the temperature on the exhaust gas sensor 5 can also be prevented by adjusting the size of the folding opening 12 to prevent excessive exhaust gas from flowing through the return path 7.

Further, the extraction pipe 4 provided with the exhaust gas sensor 5 is provided to extend obliquely upward from the wall of the exhaust pipe 2, and the exhaust sensor 5 is turned upside down in the upward recess 8 provided in the return path 7 of the extraction pipe 4. Therefore, it is possible to prevent the condensation water from staying in the extraction pipe 4 and the recess 8, prevent the exhaust gas flow path from being blocked, and prevent the exhaust gas sensor 5 from being flooded.

  Moreover, the exhaust pipe measuring device 1 can be manufactured with a simple, inexpensive and stable quality by making the extraction pipe 4 a double pipe structure of the outer pipe 9 and the inner pipe 10.

  The configuration for preventing the influence of the flow velocity will be described in more detail just in case. First, in order to reliably introduce exhaust gas into the extraction pipe 4 even when the flow rate of exhaust gas in the exhaust cylinder 2 is slow, the inlet to the extraction pipe 4 is configured to receive the dynamic pressure of the exhaust gas. That is, typically, the inlet to the extraction pipe 4 may be directed to the upstream side of the exhaust gas flowing through the exhaust pipe 2. On the other hand, the outlet from the extraction pipe 4 is directed in a direction that is less susceptible to the dynamic pressure of the exhaust gas. Typically, the outlet from the extraction pipe 4 may be directed in a direction orthogonal to the flow of exhaust gas flowing through the exhaust pipe 2. In this way, it is possible to reliably generate a flow of exhaust gas in the extraction pipe even at a low flow rate. On the contrary, in order to prevent the influence when the flow velocity of the exhaust gas in the exhaust pipe 2 is high, the sensor installation position is made not in the return path 7 but in the concave portion 8 that is an upward concave portion 8 that becomes a closed space. An exhaust gas sensor 5 is arranged. Therefore, compared with the case where the exhaust gas sensor 5 is directly installed in the flow path of the extraction pipe 4, it can be made less susceptible to the influence of the flow velocity. In this way, a wide range of flow rates (for example, 1 to 15 m / s in the case of the boiler 3) can be handled.

  As described above, for example, even when a contact combustion type CO sensor is used as the exhaust gas sensor 5, it is possible to reliably detect incomplete combustion of a combustion device by preventing the influence of flow velocity, temperature, and condensation. it can. Moreover, for example, in the case of the boiler 3, the flow rate and temperature of the exhaust gas and the generation state of the dew condensation water are different for each model, but according to the exhaust gas measuring device 1 of this embodiment, the same configuration is used for various boilers 3. It becomes possible to respond. Note that if the output of the exhaust gas sensor 5 (for example, the concentration of carbon monoxide in the case of a CO sensor) exceeds a set value, an alarm may be issued or the combustion of the combustion device (boiler 3) may be stopped.

  4 and 5 are schematic views showing a state in which the exhaust gas measuring device 1 of the above-described embodiment is installed in a sideways exhaust pipe 2 called lateral pulling, FIG. 4 is a front view, and FIG. It is sectional drawing.

  The exhaust gas measuring device 1 is provided in the exhaust pipe 2 along the vertical direction in FIG. 1, but is provided in the exhaust pipe 2 along the horizontal direction in FIG. 4. In other words, as shown in the example, the exhaust pipe 2 from the combustion equipment such as the boiler 3 may be provided sideways along the ceiling of the building, and the exhaust gas measuring device 1 is also provided in the same configuration at that location. Can be installed.

  Specifically, as shown in FIG. 5, a measurement port 24 similar to FIG. 1 or an appropriate bracket is provided on a part of the peripheral side wall of the sideways exhaust pipe 2. As in the case of FIG. 1, the exhaust gas measuring device 1 can be installed. At this time, the opening of the switching port 30 is arranged toward the upstream side of the exhaust gas. In this case, the exhaust gas passing through the horizontal exhaust cylinder 2 can be applied to the first plate 31 of the switching port 30 and guided to the inner pipe 10. As described above, the switching port 30 of the present embodiment can cope with the exhaust pipe 2 in a vertical configuration and a horizontal configuration with a common configuration.

  The exhaust gas measuring device 1 of the present invention is not limited to the configuration of the above embodiment, and can be changed as appropriate. In the above embodiment, the inner pipe 10 is inserted into the outer pipe 9, but the configuration method is not particularly limited as long as the shape is substantially the same. Moreover, the cross-sectional shape of the outer pipe 9 and the inner pipe 10 is not necessarily limited to a rectangular shape. Furthermore, the switching port 30 provided at the tip of the inner pipe 10 can be changed as appropriate.

1 Exhaust gas measuring device 2 Exhaust tube (exhaust gas passage)
3 Boiler (combustion equipment)
4 Extraction pipe 5 Exhaust gas sensor 6 Take-out path 7 Return path 8 Recess 9 Outer pipe 10 Inner pipe 11 End wall 12 Turn-back opening 30 Switching port

Claims (5)

Provided obliquely upward on the wall of the exhaust gas path from the combustion equipment, take out a part of the exhaust gas passing through the exhaust gas path through the take-out path, fold back at the end of the take-out path, and via the return path An extraction pipe that returns to the exhaust gas path,
An exhaust gas sensor that is installed in an upward recess provided in the return path and detects the concentration of carbon monoxide, carbon dioxide, oxygen, or nitrogen oxides in the exhaust gas ;
The extraction pipe is composed of an outer pipe having a rectangular section and an inner pipe having a rectangular section that is fitted into the lower half of the section of the outer pipe,
The outer pipe is provided so that one end is closed by an end wall and the other end is opened to the exhaust gas path,
The inner pipe has a folded opening formed by disposing one end portion away from the end wall, or a folded opening is formed on the upper wall on the one end side while the one end portion is closed, The other end is provided to extend from the outer pipe and open to the exhaust gas path,
The outer pipe is provided with a concave portion on the upper wall on the downstream side from the folding opening,
An upper portion of the concave portion is closed , and the exhaust gas sensor is provided in the concave portion. The exhaust pipe measuring apparatus according to claim 1 , wherein the inner pipe is provided with a tip portion thereof penetrating into the exhaust gas passage. The inner pipe and the outer pipe, with an angle of more than 30 degrees to the horizontal state, according to claim 1 or claim 2, characterized in that it is provided obliquely upward accordingly spaced from the walls of the exhaust gas channel Exhaust gas measuring device. Against the exhaust gas passing through the exhaust gas channel, switching port for guiding a part of exhaust gas into said pipe, any one of claims 1 to 3, characterized in that provided on the other end of the pipe The exhaust gas measuring device according to 1. The exhaust gas measuring device according to claim 4 , wherein the switching port has a shape in which the exhaust gas path corresponds to both a vertical direction and a horizontal direction.

Images