JP2010139340A - Exhaust gas measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas measuring device capable of acquiring reliability of high mass emission measurement even during low emission measurement. <P>SOLUTION: The exhaust gas measuring device 1 determines whether an internal combustion engine is in an operation state or not by a dilution gas concentration measuring means, an operation state detection means, an operation decision means, a diluted exhaust gas collection means, a diluted exhaust gas concentration calculation means, and an exhaust gas concentration calculation means, and when determined to be in the operation state, collects part of the diluted exhaust gas in a dilution tunnel 21 and measures its concentration, and executing control for calculating mass emission based on measurement results of a B/G (background) concentration and a diluted exhaust gas concentration, to thereby suppress excessive dilution of the exhaust gas for concentration measurement. Consequently, the reliability of high mass emission measurement can be acquired even during low emission measurement. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust gas measuring device.

Conventionally, in order to quantitatively analyze the components contained in the exhaust gas of an internal combustion engine of a vehicle, a continuous mass using CVS (Constant Volume Sampling) that measures the components after the exhaust gas is diluted to a predetermined ratio with a diluent gas Emission measurement is widely performed (see, for example, Patent Document 1).
In the continuous mass emission measurement by CVS, the dilution rate of the exhaust gas changes according to the amount of exhaust gas taken into the CVS from the internal combustion engine on the principle of the measurement. Therefore, when the amount of exhaust gas discharged from the internal combustion engine is small, such as during idle operation or low load operation, the small amount of exhaust gas taken into the CVS is greatly diluted in the dilution tunnel and stored in the sample bag. . As described above, when the exhaust gas for concentration measurement is diluted to a large extent, the sensitivity of the measurement is lowered, so that the reliability of continuous mass emission measurement may be lowered.

As a means to improve the reliability of continuous mass emission measurement by CVS, open air valve and collect exhaust gas in a spherical tank at any time, automatic analysis of highly adsorbable exhaust gas with reproducibility The technique to do is disclosed by patent document 2. FIG.
In addition, it is equipped with a variable venturi type constant flow control device that automatically controls the cross-sectional area of the throat section, and sample gas for bag sample is collected at a constant flow rate through the sample line and valve under the conditions specified for each mode operation. Thus, Patent Document 3 discloses a technique for controlling the gas mass flow rate to be constant even when the exhaust gas condition changes greatly.

Japanese Patent No. 3004751 Japanese Patent No. 2590385 Japanese Patent No. 2945499

  However, in the techniques of Patent Documents 2 and 3, it is difficult to prevent the exhaust gas for concentration measurement from being excessively diluted when the amount of exhaust gas discharged from the internal combustion engine is small. In particular, in the case of low emission measurement in HEV (Hybrid Electric Vehicle) or the like, in order to store the gas in the dilution tunnel in the sample bag even when the internal combustion engine is stopped, that is, when the exhaust gas amount is zero, Exhaust gas is diluted excessively. Therefore, there is a problem that the reliability of continuous mass emission measurement is greatly lowered because the sensitivity of measurement is lowered.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an exhaust gas measuring device capable of obtaining high mass emission measurement reliability even during low emission measurement.

  In order to achieve the above object, the exhaust gas measuring device of the present invention is configured to dilute the exhaust gas discharged from the internal combustion engine to a predetermined ratio with a dilution gas and supply the diluted exhaust gas to the analysis unit. An exhaust gas measuring device configured, wherein the dilution gas concentration measuring means for measuring the concentration of the dilution gas, the operating state detecting means for detecting the operating state of the internal combustion engine, and the detection of the operating state detecting means Based on the result, an operation determining means for determining whether or not the internal combustion engine is in an operating state; and when the operation determining means determines that the internal combustion engine is operating, the diluted exhaust gas Diluted exhaust gas sampling means, diluted exhaust gas concentration measuring means for measuring the concentration of diluted exhaust gas collected by the diluted exhaust gas sampling means, and dilution gas concentration measuring means And on the basis of the measurement result of the dilution exhaust gas concentration measuring device, characterized in that it comprises an exhaust gas concentration calculating means for calculating the concentration of exhaust gas discharged from the internal combustion engine.

  According to the exhaust gas measuring apparatus of the present invention, it is determined whether or not the internal combustion engine is in an operating state, and when it is determined that the internal combustion engine is in an operating state, a part of the exhaust gas in the dilution tunnel is sampled and continuous mass emission is performed. Since the measurement can be executed, it is possible to prevent the exhaust gas for concentration measurement from being excessively diluted. Therefore, high reliability of mass emission measurement can be obtained even at the time of low emission measurement.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of an exhaust gas measuring device 1 of the present invention.

An exhaust gas measuring apparatus 1 shown in FIG. 1 includes an ECU (Electronic Control Unit) 10 and operates by receiving power supplied through a power supply line, and comprehensively controls the operation of the apparatus. Further, the exhaust gas measuring device 1 includes a dilution tunnel 21 and dilutes the exhaust gas of the internal combustion engine introduced from the exhaust gas introduction pipe 23 to a predetermined concentration. The exhaust gas measuring device 1 includes a CFV (Critical Flow Venturi) 24 and controls the flow rate of the diluted exhaust gas through the dilution tunnel 21 to be constant. Further, the exhaust gas measuring device 1 includes a background bag (hereinafter abbreviated as (B / G)) bag 25 and a sample bag 26, and a dilution tunnel through a dilution gas sampling passage 61 and a diluted exhaust gas sampling passage 62, respectively. The gas for dilution in 21 and a part of the diluted exhaust gas are collected. In addition, the exhaust gas measuring device 1 includes line switching valves 31 and 32 in the dilution gas sampling passage 61 and the diluted exhaust gas sampling passage 62, respectively, so that the gas flow rate taken into the B / G bag 25 and the sample bag 26 can be adjusted. Control. The exhaust gas measuring device 1 includes a continuous analyzer 27, and analyzes the component concentration of the gas collected in the B / G bag 25 and the sample bag 26 to perform quantitative analysis of the diluted exhaust gas. Execute. Further, the exhaust gas measuring device 1 includes a CO ₂ sensor 51 in the diluted exhaust gas collection passage 62, and detects the CO ₂ concentration of the gas passing through the diluted exhaust gas collection passage 62.

  The dilution tunnel 21 is provided with an exhaust gas introduction pipe 23 in the vicinity of the bottom thereof, and introduces exhaust gas discharged from the vehicle engine into the dilution tunnel 21. In addition, the dilution tunnel 21 is provided with an air filter 22 provided with activated carbon at the inlet of the dilution gas. The air in the laboratory passes through the air filter 22 and enters the dilution tunnel 21, and is mixed with the exhaust gas introduced from the exhaust gas introduction pipe 23, thereby diluting the exhaust gas to a predetermined concentration. The dilution ratio of the exhaust gas is determined by the components contained in the exhaust gas, and is diluted at a ratio that does not cause condensation by adjusting the opening area of the air filter 22. In this case, it is also possible to provide a separate gas cylinder and supply the dilution gas used for dilution of the exhaust gas from the gas cylinder.

  The CFV 24 is provided on the downstream side of the air filter 22 and the exhaust gas introduction pipe 23, and the exhaust gas diluted in the dilution tunnel 21 can be passed by providing a gas passage therein. The CFV 24 is configured such that a partial cross-sectional area of the gas passage is reduced to be smaller than a cross-sectional area of the other part. The exhaust gas diluted in the dilution tunnel 21 is directed to the CFV 24 by driving a blower (not shown) provided downstream of the CFV 24. The flow rate of the gas is controlled to be constant as the gas flow velocity reaches the sea flow velocity (sound velocity at the temperature) by narrowing the flow when passing through the CFV 24. In this case, a venturi flow meter (VFM) capable of continuously changing the flow rate may be provided instead of the CFV 24. The CFV 24 detects the gas volume passing through the CFV 24 and transmits the detection result to the ECU 10.

The B / G bag 25 and the sample bag 26 store gas in the inside thereof by an extendable configuration. The B / G bag 25 is provided on the downstream side of the air filter 22 and on the upstream side of the exhaust gas introduction pipe 23, and is used for dilution gas through a dilution gas collection passage 61 communicated with the dilution tunnel 21 by the driving force of the pump 41. A part of is collected. The sample bag 26 is provided on the downstream side of the air filter 22 and the exhaust gas introduction pipe 23 and on the upstream side of the CFV 24, and is connected to the dilution tunnel 21 through the diluted exhaust gas collection passage 62 communicated with the dilution tunnel 21 by the driving force of the pump 41. A part of the exhaust gas diluted in is collected. When the gas collection is completed, the B / G bag 25 and the sample bag 26 supply the collected gas to a continuous analyzer 27 described later.
The sample bag 26 and the diluted exhaust gas collection passage 62 correspond to the diluted exhaust gas collection means of the present invention.

The line switching valve 31 is a three-way valve in which one is in communication with the dilution tunnel 21, the other is in communication with the B / G bag 25, and the other is in communication with a bypass part opened to the atmosphere. The line switching valve 31 switches the communication between the dilution tunnel 21 and the B / G bag 25 or the bypass unit according to an instruction from the ECU 10 to control the collection and stop of the dilution gas.
The line switching valve 32 is a three-way valve in which one is in communication with the dilution tunnel 21, the other is in communication with the sample bag 26, and the other is in communication with a bypass part opened to the atmosphere. The line switching valve 32 controls the collection and stop of the diluted exhaust gas by switching the communication between the dilution tunnel 21 and the sample bag 26 or the bypass unit in accordance with an instruction from the ECU 10. In this case, an electromagnetic valve or an actuator can be applied as the line switching valves 31 and 32. Further, the line switching valves 31 and 32 replace the control valve of the type that controls the sampling and stopping of the gas by controlling the communication and blocking of the dilution gas sampling passage 61 and the diluted exhaust gas sampling passage 62 with a three-way valve. It can also be applied.
The line switching valve 32 corresponds to the diluted exhaust gas collecting means of the present invention.

The continuous analyzer 27 quantitatively analyzes the gas collected by the B / G bag 25 and the sample bag 26 and transmits the analysis result to the ECU 10. The continuous analyzer 27 is, for example, a non-dispersive infrared absorption meter (NDIR) as a quantitative analysis of CO and CO _2, a hydrogen flame ion detector (HFID) as a quantitative analysis of HC, and a chemiluminescence detector (as a quantitative analysis of NOx). CLD) is applied, but a Fourier transform infrared spectrometer (FTIR) or an automatic gas chromatograph can also be applied.
The continuous analyzer 27 corresponds to the dilution gas concentration measuring means and the diluted exhaust gas concentration measuring means of the present invention.

The CO ₂ sensor 51 is provided in the diluted exhaust gas collection passage 62 between the dilution tunnel 21 and the line switching valve 32, detects the CO ₂ concentration of the gas passing through the diluted exhaust gas collection passage 62, and the detection result is sent to the ECU 10. Send to. As the CO ₂ sensor 51, a general sensor such as an infrared absorption method or an electromotive force detection method can be used. In this case, instead of the CO ₂ sensor 51, the gas passing through the diluted exhaust gas collection passage 62 between the dilution tunnel 21 and the line switching valve 32 is supplied to the continuous analyzer 27 to detect the CO ₂ concentration of the gas. You can also
Note that the CO ₂ sensor 51 corresponds to the operating state detecting means of the present invention.

  The ECU 10 reads the detection result of the CFV 24 and the like and the analysis result of the continuous analyzer 27, and supplies the gas to the B / G bag 25 and the sample bag 26, the switching operation of the line switching valves 31 and 32, the operation of the pump 41, the air The operation of the exhaust gas measuring device 1 such as opening / closing operation of the filter 22 and purging inside the device is controlled in an integrated manner.

  Further, the ECU 10 instructs the B / G bag 25 to turn on the pump 41 and to switch the line switching valve 31 to sample collection ON, that is, to switch the dilution tunnel 21 and the B / G bag 25 to communicate with each other. Store the dilution gas. Subsequently, the ECU 10 performs dilution gas concentration measurement control for supplying the dilution gas stored in the B / G bag 25 to the continuous analyzer 27 and measuring the dilution gas concentration, that is, the B / G concentration. In this case, the measurement of the B / G concentration can be executed at an arbitrary timing that does not overlap with the measurement timing of the diluted exhaust gas concentration described later.

Then, the ECU 10 executes driving determination control for determining whether or not the vehicle engine is in a driving state based on the detection result of the CO ₂ sensor 51. When the CO ₂ concentration detected by the CO ₂ sensor 51 exceeds a predetermined threshold, the ECU 10 determines that the vehicle engine is in an operating state. Here, as the threshold value of the CO ₂ concentration, a sufficiently small CO ₂ concentration at which it can be determined that the engine is stopped can be applied, and can be set to, for example, 600 [ppm].
In this case, the ECU 10 operates the engine of the vehicle based on the result of analyzing the CO ₂ concentration of the gas passing through the diluted exhaust gas collection passage 62 between the dilution tunnel 21 and the line switching valve 32 by the continuous analyzer 27. It can also be determined whether or not.

Further, when the ECU 10 determines that the vehicle engine is in an operating state by the driving determination control, the ECU 10 turns on the pump 41 and turns on the line switching valve 32, that is, turns the dilution tunnel 21 and the sample bag 26 on. A command to switch to communicate is commanded, and the diluted exhaust gas is stored in the sample bag 26. Subsequently, the ECU 10 executes diluted exhaust gas concentration measurement control for measuring the diluted exhaust gas concentration by supplying the diluted exhaust gas stored in the sample bag 26 to the continuous analyzer 27.
By performing the above-described control, it is possible to suppress the exhaust gas for concentration measurement from being excessively diluted particularly during low emission measurement. Therefore, the diluted exhaust gas concentration C used in the expression (1) described later is used. It is possible to greatly improve the reliability of the measured value of t.

Then, the ECU 10 executes exhaust gas concentration calculation control for calculating the mass emission Mt from the following equations (1) and (2) based on the measurement results of the B / G concentration and the diluted exhaust gas concentration, and the detection results of the CFV 24. .
[Mass emission formula]
Ct = C′t− (1-1 / DFt) × C _BG (1)
Mt = Ct × Vt × component density (2)
(C't: diluting the exhaust gas concentration, DFt: exhaust gas _{dilution, C} BG: B / G concentration, Vt: gas volume)

  FIG. 2 shows a trial calculation for improving the CVS analysis concentration according to the present invention. According to the present invention, since the exhaust gas concentration can be calculated based on the measured value of the diluted exhaust gas concentration C′t with high reliability, the analysis concentration of mass emission can be improved more than twice as compared with the prior art. Can do. As described above, since it is possible to suppress a decrease in measurement sensitivity due to excessive dilution of exhaust gas, high reliability of mass emission measurement can be obtained even during low emission measurement such as HEV.

FIG. 3 shows a hardware configuration of the microcomputer 70 of the ECU 10. The microcomputer 70 includes a CPU 71, ROM 72, RAM 73, NVRAM (Non Volatile RAM) 74, an input / output unit 75, and the like. The CPU 71 reads a program stored in the ROM 72 and performs a calculation according to this program. That is, the CPU 71 reads the program stored in the ROM 72 to control the operation of the apparatus in an integrated manner or to execute exhaust gas concentration calculation control. Further, the RAM 73 is written with data of calculation results such as mass emission calculation, and the NVRAM 74 is the data that has been written in the RAM 73 and data that needs to be saved when the apparatus is turned off. The input / output unit 75 includes a gas volume signal passing through the CFV 24, a gas concentration signal measured by the continuous analyzer 27, a gas storage signal of the B / G bag 25 and the sample bag 26, a CO ₂ concentration signal of the CO ₂ sensor 51, and air. Signals from various devices such as a dilution gas flow rate signal passing through the filter 22 are input or output.
The ECU 10 corresponds to an operation determination unit and an exhaust gas concentration calculation unit of the present invention.

  Next, the operation of the exhaust gas measuring device 1 will be described along the control flow of the ECU 10. FIG. 4 is a flowchart showing an example of processing of the ECU 10. The exhaust gas measuring apparatus 1 of the present embodiment includes a dilution gas concentration measuring means, an operation state detecting means, an operation determining means, a diluted exhaust gas collecting means, a diluted exhaust gas concentration measuring means, and an exhaust gas concentration calculating means. To determine whether or not the internal combustion engine is in an operating state, and if it is determined to be in an operating state, collect a portion of the diluted exhaust gas in the dilution tunnel and measure its concentration. Then, control is performed to calculate mass emission based on the measurement results of the B / G concentration and the diluted exhaust gas concentration.

  First, the flow for measuring the B / G concentration will be described. The control of the ECU 10 starts when a request for starting the apparatus is made, that is, when the power is turned on. In step S <b> 1, the ECU 10 instructs the line switching valve 31 to turn on sampling, and stores the dilution gas passing through the dilution tunnel 21 in the B / G bag 25. After finishing the process of step S1, the ECU 10 proceeds to the next step S2.

In step S2, the ECU 10 supplies the dilution gas stored in step S1 to the continuous analyzer 27 and measures the B / G concentration _CBG . When the ECU 10 finishes the process of step S2, the ECU 10 ends the control process.
Note that the control processing in steps S1 and S2 can be executed at an arbitrary processing timing that does not overlap with step S7, but before step S8 described later.

  Next, a flow for calculating the exhaust gas concentration will be described. FIG. 5 is a flowchart showing an example of processing of the ECU 10. The control of the ECU 10 starts when a request for starting the apparatus is made, that is, when the power is turned on. First, in step S3, the ECU 10 instructs the line switching valve 32 to turn off sample collection, and shuts off the dilution tunnel 21 and the sample bag 26. By executing this process, the gas passing through the dilution tunnel 21 can be prevented from entering the sample bag 26. After finishing the process of step S3, the ECU 10 proceeds to the next step S4.

In step S < _b > 4, the ECU 10 detects the CO ₂ concentration of the gas passing through the diluted exhaust gas collection passage 62 based on the detection result of the CO ₂ sensor 51. After finishing the process of step S4, the ECU 10 proceeds to the next step S5.

In step S5, the ECU 10 determines whether or not the CO ₂ concentration of the gas passing through the diluted exhaust gas collection passage 62 detected in step S4 exceeds a predetermined threshold value. Here, since the threshold value of the CO ₂ concentration has been described above, a detailed description thereof will be omitted. If the CO ₂ concentration does not exceed the predetermined threshold value (step S5 / NO), the ECU 10 determines that the operation of the vehicle engine is stopped, returns to step S3, and the CO ₂ concentration is a predetermined threshold value. The above processing is repeated until the value is exceeded. If the CO ₂ concentration exceeds the predetermined threshold value (step S5 / YES), the ECU 10 proceeds to the next step S6.

  In step S6, the ECU 10 determines that the engine of the vehicle is in an operating state, instructs the line switching valve 32 to turn on sampling, and supplies the diluted exhaust gas passing through the dilution tunnel 21 to the sample bag. 26 to store. By performing this process, it is possible to suppress the exhaust gas for concentration measurement from being excessively diluted, particularly during low emission measurement, so that the reliability of the measured value of the diluted exhaust gas concentration C′t can be improved. It can be greatly improved. When the ECU 10 finishes step S6, the ECU 10 proceeds to next step S7.

  In step S7, the ECU 10 supplies the diluted exhaust gas stored in step S6 to the continuous analyzer 27 and measures the diluted exhaust gas concentration C't. After finishing the process of step S7, the ECU 10 proceeds to the next step S8.

In step S8, ECU 10, based a B / G concentration _{C BG} measured in step S2, the dilute exhaust gas concentration C't measured in step S7, the gas volume Vt of CFV24 has detected, the above-described (1 ) The exhaust gas concentration of the vehicle is calculated from the equation (2). In this way, by suppressing the decrease in measurement sensitivity due to excessive dilution of exhaust gas, high mass emission measurement reliability can be obtained even during low emission measurement such as HEV (see FIG. 2). ECU10 complete | finishes the process of control, after finishing the process of step S8.

  As described above, the exhaust gas measuring device of the present embodiment includes the dilution gas concentration measuring means, the operation state detecting means, the operation determining means, the diluted exhaust gas collecting means, the diluted exhaust gas concentration measuring means, and the exhaust gas. The gas concentration calculation means determines whether the internal combustion engine is in an operating state, and if it is determined to be in an operating state, collects a part of the diluted exhaust gas in the dilution tunnel and measures its concentration In addition, by executing the control for calculating the mass emission based on the measurement result of the B / G concentration and the diluted exhaust gas concentration, it is possible to suppress the exhaust gas for concentration measurement from being excessively diluted. . Therefore, high reliability of mass emission measurement can be obtained even at the time of low emission measurement.

  Next, a second embodiment of the present invention will be described. The exhaust gas measuring device 2 of the present embodiment has substantially the same configuration as the exhaust gas measuring device 1 of the first embodiment, but the exhaust gas measuring device 2 detects information from an engine ECU mounted on the vehicle. This is different from the vehicle control system 1 in that the operating state of the internal combustion engine is detected.

  FIG. 6 is a configuration diagram showing a schematic configuration of the exhaust gas measuring device 2 of the present invention. In addition, about the component similar to Example 1, the same reference number is attached | subjected in drawing and the detailed description is abbreviate | omitted.

The exhaust gas measuring device 2 of the present embodiment includes an ECU 10 inside the device as in the first embodiment. The exhaust gas measurement device 2 includes a communication unit 52 that allows the ECU 10 and an engine ECU mounted on the vehicle to communicate with each other. The ECU 10 and the communication unit 52 detect information related to the operating state of the engine from the engine ECU mounted on the vehicle, and determine whether or not the engine of the vehicle is in the operating state based on the detection result. In this case, the engine ECU is not limited to detecting information related to the operating state, and other engine operating state detecting means may be employed. As the communication unit 52, a communication protocol such as CAN (Controller Area Network) can be used.
In addition, ECU10 and the communication part 52 are corresponded to the driving | running state detection means of this invention.

Subsequently, the operation of the exhaust gas measuring device 2 will be described along the flow of control of the ECU 10. FIG. 7 is a flowchart showing an example of processing of the ECU 10. The ECU 10 of the exhaust gas measurement device 2 performs the following control from step S9 to step S14 while performing the control processing of step S1 and step S2 of the exhaust gas measurement device 1 of the first embodiment. Therefore, since the control of step S1 and step S2 is the same as that of the exhaust gas measuring apparatus 1 of the first embodiment, detailed description thereof is omitted.
The exhaust gas measuring device 2 of the present embodiment determines whether or not the internal combustion engine is in an operating state based on information from an engine ECU mounted on the vehicle, and when it is determined that the internal combustion engine is in an operating state, the dilution in the dilution tunnel A part of the exhaust gas thus collected is collected, its concentration is measured, and control for calculating mass emission based on the measurement results of the B / G concentration and the diluted exhaust gas concentration is executed.

  The control of the ECU 10 starts when a request for starting the apparatus is made, that is, when the power is turned on. First, in step S9, the ECU 10 instructs the line switching valve 32 to turn off sample collection, and shuts off the dilution tunnel 21 and the sample bag 26. By executing this process, the gas passing through the dilution tunnel 21 can be prevented from entering the sample bag 26. After finishing the process of step S9, the ECU 10 proceeds to the next step S10.

  In step S <b> 10, the ECU 10 detects information related to the engine operating state from the engine ECU mounted on the vehicle through the communication unit 52. When the ECU 10 finishes the process of step S10, the ECU 10 proceeds to next step S11.

  In step S11, the ECU 10 determines whether or not the vehicle engine is in an operating state based on the information related to the engine operating state detected in step S10. When the engine is not in the operating state, that is, in the stopped state (step S11 / NO), the ECU 10 returns to step S9 and repeats the above processing until the engine is in the operating state. If the engine is in an operating state (step S11 / YES), the ECU 10 proceeds to the next step S12.

  In step S <b> 12, the ECU 10 instructs the line switching valve 32 to turn on sampling, and stores the diluted exhaust gas passing through the dilution tunnel 21 in the sample bag 26. By performing this process, it is possible to suppress the exhaust gas for concentration measurement from being excessively diluted, particularly during low emission measurement, so that the reliability of the measured value of the diluted exhaust gas concentration C′t can be improved. It can be greatly improved. After finishing the process of step S12, the ECU 10 proceeds to the next step S13.

  In step S13, the ECU 10 supplies the diluted exhaust gas stored in step S12 to the continuous analyzer 27 and measures the diluted exhaust gas concentration C't. After finishing the process of step S13, the ECU 10 proceeds to the next step S14.

In step S14, ECU 10, based a B / G concentration _{C BG} measured in step S2, the dilute exhaust gas concentration C't measured in step S13, to the gas volume Vt of CFV24 has detected, the above-described (1 ) The exhaust gas concentration of the vehicle is calculated from the equation (2). Thus, by suppressing the decrease in measurement sensitivity due to excessive dilution of exhaust gas, high mass emission measurement reliability can be obtained even during low emission measurement such as HEV. ECU10 complete | finishes the process of control, after finishing the process of step S14.

  As described above, the exhaust gas measuring device according to the present embodiment determines whether or not the internal combustion engine is in an operating state based on information from an engine ECU mounted on the vehicle, and dilutes when it is determined that the internal combustion engine is in an operating state. By collecting a part of the diluted exhaust gas in the tunnel, measuring its concentration, and executing control to calculate mass emission based on the measurement results of the B / G concentration and the diluted exhaust gas concentration, It is possible to prevent the exhaust gas for concentration measurement from being excessively diluted. Therefore, high reliability of mass emission measurement can be obtained even at the time of low emission measurement.

Next, Embodiment 3 of the present invention will be described. The exhaust gas measuring device 3 of the present embodiment has substantially the same configuration as that of the exhaust gas measuring device 1 of the first embodiment, but the exhaust gas measuring device 3 includes the detection result of the CO ₂ sensor 51 and the communication unit 52. This is different from the exhaust gas measuring device 1 in that it is determined whether or not the internal combustion engine is in an operating state based on both of the information of the engine ECU mounted on the vehicle detected by the ECU 10.

  By adopting such a configuration, it is possible to more accurately determine the driving state of the vehicle, and therefore it is possible to execute exhaust gas sampling control based on a highly reliable determination result. Accordingly, since it is possible to further suppress the exhaust gas for concentration measurement from being excessively diluted, higher reliability of mass emission measurement can be obtained at the time of low emission measurement.

  The above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to these, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

1 is a configuration diagram illustrating a schematic configuration of an exhaust gas measurement device according to Embodiment 1. FIG. The calculation effect of the improvement effect of the CVS analysis density | concentration by this invention is shown. It is the block diagram which showed the hardware constitutions of the microcomputer of ECU. The flow of the control which ECU of Example 1 performs is shown. The flow of the control which ECU of Example 1 performs is shown. FIG. 3 is a configuration diagram illustrating a schematic configuration of an exhaust gas measurement device according to a second embodiment. The flow of control which ECU of Example 2 performs is shown.

Explanation of symbols

1 Exhaust gas measuring device 10 ECU (operation judging means, exhaust gas concentration calculating means)
21 Dilution tunnel 22 Air filter 23 Exhaust gas introduction pipe 24 CFV
25 B / G bag 26 Sample bag (diluted exhaust gas sampling means)
27 Continuous analyzer (dilution gas concentration measuring means, diluted exhaust gas concentration measuring means)
31 line switching valve 32 line switching valve (diluted exhaust gas sampling means)
41 pump 51 CO ₂ sensor (operation state detection means)
61 Gas sampling passage for dilution 62 Diluted exhaust gas sampling passage (diluted exhaust gas sampling means)
71 CPU
72 ROM
73 RAM
74 NVRAM
75 I / O section

Claims (1)

An exhaust gas measuring apparatus configured to dilute exhaust gas discharged from an internal combustion engine to a predetermined ratio with a dilution gas and supply the diluted exhaust gas to an analysis unit,
A dilution gas concentration measuring means for measuring the concentration of the dilution gas;
An operating state detecting means for detecting an operating state of the internal combustion engine;
Driving determination means for determining whether or not the internal combustion engine is in an operating state based on a detection result of the operating state detection means;
Diluted exhaust gas collecting means for collecting the diluted exhaust gas when the operation determining means determines that the internal combustion engine is operating;
Diluted exhaust gas concentration measuring means for measuring the concentration of the diluted exhaust gas collected by the diluted exhaust gas collecting means;
Exhaust gas concentration calculating means for calculating the concentration of exhaust gas discharged from the internal combustion engine based on the measurement results of the dilution gas concentration measuring means and the diluted exhaust gas concentration measuring means;
An exhaust gas measuring device comprising:

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