JP4878981B2 - Gas analyzer - Google Patents

Description

  The present invention relates to a gas analyzer, and more specifically, to an exhaust path for exhausting exhaust gas from an internal combustion engine, irradiating the exhaust gas in the exhaust path with laser light and detecting the laser light transmitted through the exhaust gas Thus, the present invention relates to a gas analyzer in which a measuring unit for measuring the component concentration and temperature of exhaust gas is arranged.

Conventionally, the gas flowing through the exhaust path is irradiated with laser light having a specific absorption wavelength, transmitted through the gas, and the reflected light reflected by the inner wall of the exhaust path or the reflecting mirror is detected. A configuration of a gas analyzer that measures and analyzes the concentration and temperature of a specific component is known.
For example, a gas analyzer disclosed in Patent Document 1 includes a gas cell equivalent unit capable of multiple reflection of laser light, a light source unit that emits laser light so that the focal position can be changed, and a detector unit that detects reflected light. Are arranged at predetermined locations in the exhaust path to measure the concentration of a specific component in the gas (see Patent Document 1).

Further, regarding such a gas analyzer, a configuration of a gas analyzer that measures and analyzes a component concentration contained in exhaust gas of an internal combustion engine such as an automobile is known.
For example, in the gas analyzer disclosed in Patent Document 2, a measurement unit that continuously measures the concentration of components in exhaust gas is provided in one of the exhaust paths through which the exhaust gas passes. The exhaust gas discharged from an internal combustion engine such as an engine is taken out from the middle of the exhaust path, and the concentration of THC (Total Hydro Carbon) in the exhaust gas is measured using an analysis method such as infrared absorption ( Patent Document 2).
JP 2004-53405 A JP 2004-117259 A

By the way, in the gas analyzer disclosed in Patent Document 2 described above, when measuring the component concentration of exhaust gas, etc., it is necessary to take the exhaust gas from the exhaust path and measure it once. It is not possible to measure the state of the exhaust gas flowing through the wall in real time.
Therefore, as a gas analyzer for measuring the concentration of exhaust gas components in an internal combustion engine in real time, for example, as disclosed in Patent Document 1 described above, a light source, a detector unit, etc. It is preferable that the measuring device is directly arranged to measure the component concentration or the like in the exhaust gas by detecting laser light transmitted through the exhaust gas flowing through the exhaust path.

  However, since the temperature of the exhaust gas from the internal combustion engine decreases as it goes from the engine upstream of the exhaust path to the exhaust pipe downstream, the temperature of the exhaust gas is particularly low in the exhaust pipe at the end of the exhaust path. Water vapor in the exhaust gas is liquefied. For this reason, when a measuring unit is provided at the end of such an exhaust path, the laser light is scattered or refracted by droplets scattered on the exhaust path or droplets attached to the inner wall of the exhaust path or the sensor unit of the measuring unit. -Loss due to absorption or the like, there is a problem that the laser beam cannot be detected with high accuracy and the measurement accuracy of exhaust gas is inferior.

  In particular, in automobiles, silencers and mufflers are provided at the end of the exhaust path, so water accumulated in the silencer etc. is scattered in the exhaust path due to the flow of exhaust gas, and the inner wall of the exhaust path and measurement There has been a problem that the scattered droplets adhere to the sensor unit of the apparatus.

  Therefore, the present invention relates to a gas analyzer that solves the above-described conventional problems, and provides a gas analyzer that can accurately measure the concentration of exhaust gas components in real time even at the end of the exhaust path. It is intended to do.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

That is, in claim 1, the exhaust gas exhaust gas discharged from the internal combustion engine is irradiated with laser light on the exhaust gas in the exhaust gas path, and the laser light transmitted through the exhaust gas is detected, whereby the exhaust gas component concentration Or a gas analyzer having a measuring unit for measuring temperature, wherein the measuring unit is arranged at a terminal part of the exhaust path via a connection part formed by an internal hollow cylindrical member, The connection portion is formed such that one end portion is connected to the end portion of the exhaust path, the other end portion is bent substantially vertically upward, and a drain hole penetrating the internal space and the external space is formed. drain portion is provided with said measuring unit is shall be attached to the other end portion of the connecting portion.

  According to a second aspect of the present invention, the connecting portion is formed with a bent portion bent substantially at a right angle between the one end portion and the other end portion.

  According to a third aspect of the present invention, the drain portion is provided between the one end portion and the bent portion of the connecting portion and in the vicinity of the bent portion, and the drain hole is opened substantially vertically downward. is there.

  According to a fourth aspect of the present invention, the measurement part, the connection part, and the drain part are assembled together and are detachable from the end part of the exhaust path.

  According to a fifth aspect of the present invention, the measurement section has an inner diameter smaller than the inner diameter of the connection section formed through the exhaust gas.

  According to a sixth aspect of the present invention, the measurement unit is provided with an extension unit that discharges the exhaust gas sent from the connection unit while guiding the exhaust gas.

  As effects of the present invention, the following effects can be obtained.

  Since it is set as the structure shown in Claim 1, the component density | concentration etc. of waste gas can be measured in real time and accurately, without being influenced by the water | moisture content in an exhaust path in a measurement part.

  Since it was set as the structure shown in Claim 2, it can comprise simply and can reduce manufacturing cost.

  Since it was set as the structure shown in Claim 3, the internal water collected in the vicinity of the bending part can be discharged | emitted effectively outside the apparatus.

  Since the configuration shown in claim 4 is adopted, the connecting portion can be easily attached to and detached from the end portion of the exhaust passage, and the concentration analysis of the exhaust gas of the internal combustion engine can be easily performed.

  With the configuration shown in claim 5, even when the flow rate of the exhaust gas flowing through the exhaust path is fast and the droplet in the exhaust gas reaches the other end of the connection portion, the droplet does not pass through the through hole. It can prevent reaching the inside.

  Since it is the structure shown in Claim 6, even if it is a case where the inside of an exhaust path and the inside of a connection part becomes a negative pressure temporarily, it prevents that external air mixes into a measurement part and a connection part, Measurement accuracy can be further improved.

Next, the best mode for carrying out the invention will be described.
1 is a side view showing a state in which a gas analyzer according to an embodiment of the present invention is mounted on a vehicle, FIG. 2 is a side view of a measurement unit, and FIG. 3 is a perspective view showing a state in which a sensor body is disassembled, 4 is a side view showing the arrangement of the measurement unit, the connection unit, and the drain unit provided at the end of the exhaust path, FIG. 5 is a side sectional view of FIG. 4, and FIG. 6 is a connection unit of FIG. FIG. 7 is a side view showing an arrangement configuration of the measurement part, the connection part, and the drain part provided at the end part of the exhaust path of another embodiment.

First, the overall configuration of the gas analyzer 1 of this embodiment will be outlined below.
As shown in FIG. 1, the gas analyzer 1 of this embodiment measures and analyzes the component concentration and temperature in the exhaust gas discharged from the engine 20 disposed in the automobile 2. Specifically, the gas analyzer 1 includes a plurality of measuring units 5, 5... Disposed at a plurality of locations in the exhaust path 3 described above, and a laser oscillation / light receiving controller connected to the measuring unit 5. 6 and a computer device 7 connected to the controller 6.

  The automobile 2 is provided with an exhaust path 3 for discharging exhaust gas from the engine 20 to the outside of the machine. The exhaust path 3 includes an exhaust manifold 30, an exhaust pipe 31, a first catalyst device 32, a second catalyst device 33, a muffler 34, It consists of an exhaust pipe 35 and the like. And each component apparatus of the exhaust path 3 is connected by the piping 3a with a circular cross section.

  In the exhaust path 3, the exhaust gas of the engine 20 is first merged in the exhaust manifold 30, introduced into the first catalyst device 32 and the second catalyst device 33 through the exhaust pipe 31, and then into the atmosphere from the exhaust pipe 35 through the muffler 34. Released. By forming such an exhaust path 3, the exhaust gas from the engine 20 is purified by the two catalytic devices 32 and 33, muffled and decompressed by the muffler 34, and released into the atmosphere.

The measurement units 5, 5... Of the present embodiment are arranged at four locations in the exhaust path 3, specifically, between the engine 20 and the exhaust pipe 31 on the upstream side of the first catalyst device 32, They are disposed between the first catalyst device 32 and the second catalyst device 33, between the second catalyst device 33 and the muffler 34, and at the end of the exhaust pipe 35 on the downstream side of the muffler 34, respectively.
Note that the measurement unit 5 (terminal measurement unit 5) disposed at the end of the exhaust pipe 35 is disposed via the connection unit 8. Details of the end measurement unit 5 will be described later (see FIGS. 1 and 4).

  In the gas analyzer 1, the exhaust gas flowing through the exhaust path 3 is received by the controller 6 in each measuring unit 5 arranged in this manner, and the laser light after passing through the exhaust gas is received by the controller 6. The component concentration of is continuously measured in real time. Then, the obtained data is sent from the controller 6 to the computer device 7 to analyze the components in the exhaust gas.

Here, the configuration of the measurement unit 5 will be outlined below.
In the gas analyzer 1 of the present embodiment, the measurement units 5, 5... Arranged in the exhaust path 3 are configured substantially the same. Hereinafter, as an example, the measurement unit 5 disposed between the first catalyst device 32 and the second catalyst device 33 will be described.
As shown in FIGS. 2 and 3, the measuring unit 5 is formed of a rectangular thin plate material, and is fixed with the sensor main body 50 sandwiched between the sensor main body 50 having a circular through hole 50 a penetrating substantially at the center. It consists of a pair of flange portions 51, 51 and the like, and is connected to a pipe 3a connected to the first catalyst device 32 and the second catalyst device 33.

  The flange portions 51 and 51 are formed by a main body portion 51a having a circular cross section and a circular through hole 51c formed in a substantially central portion, and a cylindrical portion 51b protruding from one side surface of the main body portion 51a. ing. The flange portion 51 is fastened by a bolt 52 with the other side surface of the main body portion 51 a facing each other and the sensor main body 50 sandwiched between the flange portions 51. The through hole 51c of the main body 51a is formed in a circular shape having the same diameter as the through hole 50a of the sensor main body 50. The cylindrical part 51b is fixed to the main body part 51a by welding or the like.

  The measurement unit 5 is connected to each pipe 3a of the exhaust path 3 by a cylindrical part 51b, and exhaust gas flowing through the exhaust path 3 is sent from the cylindrical part 51b of one flange part 51 to the sensor body 50 through the through hole 51c. Then, it passes through the through hole 50a of the sensor body 50 and is sent to the downstream side of the exhaust path 3 from the through hole 51c of the other flange portion 51 and the cylindrical portion 51b.

  In addition to the above-described through hole 50 a, the sensor body 50 has an infrared transmission optical fiber 53 as an irradiation unit for irradiating laser light, and a heat-resistant reflection that multi-reflects the laser light emitted from the optical fiber 53. Mirrors 54, 54, a detector 55 as a light receiving unit for detecting laser light transmitted through the exhaust gas, and heaters 56, 56 for preventing condensation in the exhaust path in the measurement unit 5 are provided.

  The optical fiber 53 and the detector 55 are installed such that the light projecting surface and the light receiving surface are directed toward the center of the through hole 50a. The optical fiber 53 and the detector 55 are connected to the controller 6 described above, and the infrared laser light emitted from the controller 6 is irradiated to the through-hole 50a through the optical fiber 53 and transmitted through the exhaust gas. Is received by the detector 55 and a light reception signal is input to the controller 6.

  The reflecting mirrors 54 and 54 are arranged in parallel so as to face the through hole 50a so as to face each other vertically, and the laser light irradiated from the optical fiber 53 is orthogonal to the exhaust path 3 in the through hole 50a. And are fixed in parallel so as to cross. The laser light emitted from the optical fiber 53 is reflected by one (lower in FIG. 3) reflecting mirror 54 toward the other (upper in FIG. 3) reflecting mirror 54, and the two reflecting mirrors 54 and 54 are reflected. Are alternately reflected and reach the detector 55 on the light receiving side. In other words, the laser light irradiated by the optical fiber 53 is reflected by the detector 55 after being reflected a plurality of times in one cross section orthogonal to the exhaust path 3.

  The controller 6 is an irradiation device that irradiates infrared laser light having a plurality of wavelengths, and the wavelength of the laser light is set according to the component of the exhaust gas to be detected. The controller 6 is provided with a differential photodetector (not shown) connected to the detector 55, and the signal light received by the detector 55 is guided and attenuated through the exhaust gas. The signal light of the laser light and the laser light not passing through the exhaust gas is detected and output to the connected computer device 7.

  In the computer device 7, the exhaust gas is analyzed by analyzing the output signal from the controller 6 and calculating the component concentration of the exhaust gas and the temperature of the exhaust gas.

  As described above, in the gas analyzer 1 of the present embodiment, the laser beam is irradiated along the cross section orthogonal to the exhaust path 3 in the measuring unit 5 and the laser beam transmitted through the exhaust gas across the exhaust path 3 is detected. Therefore, measurement with spot exhaust gas in one cross section of the exhaust path 3 is possible. In particular, as in this embodiment, by providing the measurement units 5 at a plurality of locations in the exhaust path 3, it is possible to instantaneously measure how the exhaust gas changes in a predetermined section of the exhaust path 3, and The state can be continuously measured in real time.

Next, the measurement unit 5 arranged at the end of the exhaust path 3 will be described in detail below.
As shown in FIGS. 4 to 6, in the gas analyzer 1 of the present embodiment, one measuring unit 5 is disposed at the end of the exhaust path 3, that is, the opening 35 a of the exhaust pipe 35 (hereinafter, referred to as “the gas analyzer 1”) The measurement unit 5 arranged at the end of the exhaust path 3 is abbreviated as “end measurement unit 5”), and the end measurement unit 5 has a connection portion 8 formed of an internal hollow cylindrical member in the opening 35a. The component concentration of the exhaust gas passing through the other end 8b of the connecting portion 8 is measured.

  As shown in FIGS. 4 and 5, the connecting portion 8 has one end 8 a connected to the opening 35 a of the exhaust pipe 35 and the other end 8 b connected to the exhaust pipe 35. It is configured to be bent substantially vertically upward. Specifically, in the connection portion 8 of the present embodiment, one bent portion 8c that is bent substantially at a right angle is formed between the one end portion 8a and the other end portion 8b. The portion between the one end portion 8a and the bent portion 8c and the portion between the bent portion 8c and the other end portion 8b are formed in a substantially linear shape, and the one end portion 8a (or the other end portion 8b) is the other end of the other end portion. The portion 8b (or one end portion 8a) is bent at a substantially right angle in the radial direction so as to be substantially L-shaped in a side view.

  The connection portion 8 is connected so that the opening portion 35a of the exhaust pipe 35 and the internal space are continuous at the one end portion 8a. In this embodiment, the one end 8a and the opening 35a are connected via the heat-resistant tube 80 and the fixing band 81, and the connecting portion 8 is connected and fixed to the exhaust pipe 35 so that the relative position cannot be changed. .

  The connecting portion 8 is fixed to the exhaust pipe 35 with the other end portion 8b facing substantially vertically upward in a state of being attached to the exhaust pipe 35 (the opening 35a thereof). In the present embodiment, since the exhaust pipe 35 has the opening 35a arranged in a substantially horizontal direction, the other end 8b of the connection part 8 attached to the exhaust pipe 35 (opening 35a) is in the horizontal direction. It is fixed so as to be directed substantially vertically upward.

  Further, the connecting portion 8 of the present embodiment is provided with a drain portion 9 in which a drain hole 90a penetrating the internal space and the external space is formed. The drain portion 9 includes a connector member 90 in which a drain hole 90a is formed, a hose 91 and the like attached to the connector member 90, and a connector member in the attachment hole 8e formed in the connection portion 8. 90 is fitted so that it fits.

  The connector member 90 is provided with a drain hole 90 a extending along the axial direction. One of the drain holes 90 a is opened toward the internal space of the connection portion 8, and the other is directed toward the external space of the connection portion 8. Opened. In the present embodiment, the drain hole 90a is always open, that is, the internal space of the connecting portion 8 and the external space are always in communication. Further, the hose 91 is formed of a cylindrical member having both ends opened.

  The drain portion 9 of the present embodiment is provided between the one end portion 8a of the connection portion 8 and the bent portion 8c so that the drain hole 90a is opened substantially vertically downward with respect to the horizontal direction. . Specifically, the drain part 9 has a connector member 90 attached to the lower surface in the vicinity of the bent part 8c of the connecting part 8 so that the drain hole 90a faces substantially vertically downward.

  As shown in FIG. 6, the configuration of the end measurement unit 5 is substantially the same as the configuration of the other measurement units 5 described above, but the configuration is partially different. That is, the end measurement unit 5 includes a sensor body 50 and a pair of flange portions 57 and 57, and the flange portion 57 is not provided with the above-described cylindrical portion (see FIG. 2). In the end measurement part 5, the main body part 57b of one flange part 57 is fixed to the other end part 8b of the connection part 8 by welding or the like. Specifically, the through hole 50a drilled in the sensor main body 50 is substantially vertical. It is fixed in an open state toward the direction.

  In particular, in the end measurement unit 5 of the present embodiment, the through hole 50a of the sensor body 50 is formed in a circular shape having the same diameter as the through hole 57c of the flange portion 57, and is attached to the other end portion 8b of the connection portion 8. In this state, the inner diameter d of the through hole 50 a of the sensor body 50 and the through hole 57 c of the flange portion 57 is formed to be smaller than the inner diameter D of the other end portion 8 b of the connection portion 8.

  However, the configuration of the flange portions 57 and 57 in the end measurement unit 5 is not particularly limited to this (for example, see FIG. 7).

  The above-described end measurement unit 5, connection unit 8, and drain unit 9 are configured as unit bodies that are assembled together. That is, as a unit body, the end measurement part 5 and the drain part 9 are fixed to the connection part 8, and the connection part 8 is detachable from the exhaust pipe 35. With this configuration, the end connection portion 5 can be easily attached to and detached from the end portion of the exhaust path 3, and the exhaust gas concentration analysis of the internal combustion engine in the automobile 2 can be easily performed.

  As described above, in the gas analyzer 1 of the present embodiment, the end measurement unit 5 disposed at the end of the exhaust path 3 is disposed via the connection portion 8 formed of an internal hollow cylindrical member. The connecting portion 8 is formed such that one end portion 8a is connected to the opening portion 35a of the exhaust pipe 35 and the other end portion 8b is bent substantially vertically upward. Since the drain portion 9 having a drain hole 90a penetrating the exhaust passage 3 is provided, the concentration of the exhaust gas component can be measured in real time without being affected by moisture in the exhaust passage 3 in the end measurement portion 5. It can be measured with high accuracy.

  That is, the exhaust gas discharged from the engine 20 is sent to the downstream side of the exhaust path 3 through the manifold 30 and the like, reaches the opening 35a of the exhaust pipe 35 which is the end, and the end is measured through the connection portion 8. Sent to part 5. Then, after the terminal concentration unit 5 measures the component concentration in the exhaust gas and the like, it is discharged outside the apparatus (arrow A in FIG. 6).

  By the way, as the exhaust gas in the exhaust path 3 is sent to the downstream side of the exhaust path 3, the temperature thereof decreases, and particularly when reaching the opening 35 a of the exhaust pipe 35, it decreases to about 100 ° C. is doing. Therefore, in the exhaust pipe 35 and the connection portion 8, the water vapor contained in the exhaust gas is liquefied, and the droplets are scattered in the internal space (see arrow B1 in FIG. 6). Further, such droplets accumulate as internal water 10 in the space below the exhaust pipe 35 and the connecting portion 8, and a part of the internal water 10 scatters as droplets in the internal space.

In the present embodiment, the other end portion 8b of the connecting portion 8 is formed to be bent substantially vertically upward, so that the liquid droplets scattered inside the connecting portion 8 collide with the inner wall at the bent portion 8c. It is attached (see arrow B2 in FIG. 6). Therefore, it is possible to prevent the liquid droplet from reaching the end measurement unit 5 provided at the other end 8b of the connection unit 8.
Moreover, since the drain part 9 is provided in the connection part 8, the internal water 10 collected in the space under the connection part 8 is discharged | emitted outside the machine through the drain hole 90a of the drain part 9 (arrow B3 in FIG. 6). Reference) and the internal water 10 can be prevented from being scattered as droplets in the internal space.
In this way, by preventing the droplets from reaching the end measurement unit 5, the component concentration of the exhaust gas is not affected by the droplets in the exhaust path 3 even at the end of the exhaust path 3. Can be measured with high accuracy. Therefore, for example, the component concentration of the exhaust gas from the engine 20 can be measured while the automobile 2 is running.

  Further, in the gas analyzer 1 of the present embodiment, the connection portion 8 is formed with a bent portion 8c bent substantially at a right angle between the one end portion 8a and the other end portion 8c, and thus the configuration is easy. Manufacturing cost can be reduced. That is, the configuration of the connecting portion 8 may be a configuration in which droplets in the exhaust gas collide with and adhere to the inner wall at the bent portion 8c, and a bent portion 8c bent substantially at a right angle is provided as such a configuration. It's enough.

  Further, the drain portion 9 is provided between the one end portion 8a and the bent portion 8c of the connecting portion 8 and in the vicinity of the bent portion 8c, and the drain hole 90a is opened substantially vertically downward. The internal water 10 accumulated in 8 can be effectively discharged outside the apparatus. That is, since the adhering liquid droplets are likely to accumulate in the vicinity of the bent portion 8c, the internal water 10 in the connecting portion 8 can be effectively discharged outside the apparatus by providing the drain portion 9 at such a position.

  In particular, in the gas analyzer 1 of the present embodiment, the measurement unit 5 is configured so that the inner diameter d of the through hole 50a drilled for the passage of exhaust gas is smaller than the inner diameter D of the other end 8b of the connection unit 8. Is formed. As described above, in this embodiment, the through hole 50a formed in the sensor main body 50 of the measurement unit 5 is formed so that the inner diameter thereof is the same as the through hole 57c of the flange portion 57. Therefore, even when the flow rate of the exhaust gas flowing through the exhaust path 3 is fast and the droplets in the exhaust gas reach the other end portion 8b of the connection portion 8, the outer peripheral edge portion of the through hole 57c of the flange portion 57 is formed. Since the droplets collide and adhere (see arrow B4 in FIG. 6), it is possible to prevent the droplets from reaching the inside of the through hole 50a of the sensor body 50.

  In addition, the structure of the gas analyzer 1 of a present Example is not limited to the above-mentioned structure.

  For example, as shown in FIG. 7, in the gas analyzer 1 of another embodiment, the end measurement unit 5 is provided with an extension 58 for discharging the exhaust gas sent from the connection unit 8 to the outside while guiding it. Yes. Specifically, the extension portion 58 is formed of an internal hollow cylindrical member, and is connected to the other end portion 8 b of the connection portion 8 among the pair of flange portions 57 and 57 constituting the end measurement portion 5. The exhaust gas passing through the end measurement unit 5 is discharged to the outside while being guided by the extension part 58, disposed on the flange part 57 opposite to that of the other end part 8 b. The extension portion 58 is fixed to one side surface of the flange portion 57 by welding or the like.

  And the extension part 58 of a present Example is the protrusion (extension) length from the flange part 57, and when the inside of the exhaust path 3 and the inside of the connection part 8 become a negative pressure, external air will enter into the extension part 58. The length is configured so as not to be mixed. That is, when the engine 20 is suddenly decelerated, the inside of the exhaust path 3 and the inside of the connection portion 8 temporarily become negative pressure, but even in such a case, outside air is mixed into the end measurement portion 5 and the connection portion 8 Thus, the exhaust gas measurement accuracy is further improved (see arrow C in FIG. 7). The extension length of the extension portion 58 from the flange portion 57 is appropriately changed depending on the output of the engine 20, the inner diameter of the other end portion 8b of the connection portion 8, the inner diameter of the through hole 50a of the end measurement portion 5, and the like. The

  Further, in the gas analyzer 1 described above, the plurality of measuring units 5 are provided in the exhaust path 3, but the arrangement and the number of the measuring units 5 are not particularly limited, for example, at the end of the exhaust path 3. Only the measurement unit 5 may be provided. In such a case, only the component concentration of the exhaust gas when discharged from the exhaust path 3 to the outside of the machine is measured.

The configuration of the measurement unit 5 is not limited to the configuration in which the sensor main body 50 is fixed by the flange portion 51 (57), and any configuration that can fix the position of the sensor main body 50 to the exhaust path 3 may be used. Further, the configuration of the sensor main body 50 is limited as long as at least an irradiation unit that irradiates the exhaust gas passing through the through hole 50a with a laser beam and a light receiving unit that receives transmitted light that has passed through the exhaust gas are provided. Not.
In particular, in the above-described embodiment, in the measurement unit 5, the inner diameter d of the through hole 50 a is configured to be smaller than the inner diameter D of the other end portion 8 b of the connection portion 8. For example, a rib is provided in the other end portion 8b toward the center so that the flow of the exhaust gas reaching the through hole 50a of the sensor body 50 is blocked, so that the droplets in the exhaust gas enter the through hole 50a. You may comprise so that it may not reach.

  Further, as the configuration of the connecting portion 8, the inner diameter, the length from the one end portion 8a to the bent portion 8c, the length from the bent portion 8c to the other end portion 8b, the bent angle of the bent portion 8c, etc. And the length and inner diameter of the exhaust passage 3 are appropriately changed.

  The drain portion 9 may be configured to discharge the internal water 10 in the connection portion 8 from the drain hole 90a to the outside of the machine. For example, a control valve (cock) for opening and closing the drain hole 90a or a discharge A tank or the like for storing the generated internal water 10 may be separately provided.

The side view which showed the state which mounted the gas analyzer which concerns on one Example of this invention in the vehicle. The side view of a measurement part. The perspective view which showed the state which decomposed | disassembled the sensor main body. The side view which showed the arrangement configuration of the measurement part, the connection part, and drain part which were provided in the terminal part of the exhaust path. The side sectional view of FIG. 4 similarly. Similarly the expanded sectional view of the connection part and measurement part of FIG. The side view which showed the arrangement configuration of the measurement part, the connection part, and drain part which were provided in the terminal part of the exhaust route of another Example.

DESCRIPTION OF SYMBOLS 1 Gas analyzer 3 Exhaust path 5 Measuring part 8 Connection part 8a One end part 8b Other end part 8c Bending part 9 Drain part 35 Exhaust pipe (terminal part)
50 Sensor Body 50a Through Hole 57 Flange 57a Through Hole 90a Drain Hole

Claims (6)

In the exhaust path for exhausting exhaust gas from internal combustion engines,
A gas analyzer in which a measurement unit that measures the component concentration and temperature of exhaust gas by irradiating the exhaust gas in the exhaust path with laser light and detecting the laser light transmitted through the exhaust gas,
The measurement unit is arranged at a terminal portion of the exhaust path via a connection unit formed by an internal hollow cylindrical member,
The connecting portion is formed so that one end is connected to the end of the exhaust path and the other end is bent substantially vertically upward, and a drain hole penetrating the internal space and the external space is formed. The drain part is provided ,
The measuring unit, the gas analyzer according to claim Rukoto attached to the other end of the connecting portion.   2. The gas analyzer according to claim 1, wherein the connection portion is formed with a bent portion that is bent at a substantially right angle between the one end portion and the other end portion.   The drain portion is provided between one end portion of the connection portion and a bent portion and in the vicinity of the bent portion, and the drain hole is opened substantially vertically downward. The gas analyzer described in 1.   The said measurement part, a connection part, and a drain part are assembled | attached integrally, and are detachable with respect to the terminal part of the said exhaust path, The Claim 1 thru | or 3 characterized by the above-mentioned. The gas analyzer as described.   5. The gas analyzer according to claim 1, wherein the measurement unit has an inner diameter of a through hole formed for passage of exhaust gas smaller than an inner diameter of the connection unit. .   The gas analyzer according to any one of claims 1 to 5, wherein the measurement unit is provided with an extension unit that discharges the exhaust gas sent from the connection unit while guiding the exhaust gas.

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