JPH0143460Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an exhaust gas sample extraction device for exhaust gas analysis of an engine body.

2. Description of the Related Art Generally, a device having a configuration as shown in FIG. 1 is known as an apparatus for analyzing the components of exhaust gas discharged from an engine body. In this Figure 1,
1 is the engine body, and 2 is the exhaust pipe. Also, 3
is a flow pipe (dilution tunnel) for diluting exhaust gas, and a blower 4 is connected to this flow pipe 3. Air is sucked into the flow pipe 3 by the blower 4 through the air filter 5. In addition, an orifice 6 and a bench lily 7 are provided in the flow pipe 3, and a discharge port 8 of the exhaust pipe 2 is provided near the orifice 6, and the exhaust gas discharged from the discharge port 8 is provided. is mixed with air in the flow pipe 3 and diluted. Furthermore, this flow pipe 3
One end of an intake pipe 9 is inserted near the bench lily 7. The other end of the intake pipe 9 is connected to an exhaust gas analyzer 11 via a bag 10 containing a certain amount of gas. The exhaust gas analyzer 11 performs component analysis of the exhaust gas.

However, in the case of the above structure, the entire exhaust gas discharged from the engine body 1 is introduced into the flow pipe 3, which has the disadvantage of increasing the size of the entire device.

Therefore, as shown in FIG.
One end of the intake pipe 23 formed by a thin tube is inserted into the exhaust pipe 22 of the intake pipe 2.
A system has been developed in which the other end of 3 is inserted into a flow pipe 24 for diluting exhaust gas and a part of the exhaust gas discharged from the engine body 21 is used, thereby reducing the size of the entire device. ing. In this case, air is introduced into the flow pipe 24 from an air compressor 25 via an air filter 26, and a small diameter ejector 27 forming a bench lily is provided in the middle of the flow pipe 24. The discharge end of the intake pipe 23 is disposed inside the ejector 27, and the exhaust gas in the exhaust pipe 22 is sucked in through the intake pipe 23 by utilizing the pressure drop of the air flowing inside the ejector 27. ing. Air and exhaust gas are mixed in the flow pipe 24, and the diluted exhaust gas is sent to the exhaust gas analyzer 29 via the intake pipe 28, where the exhaust gas is analyzed.

By the way, in the case of the above structure, the flow pipe 2
Since a part of the exhaust gas in the exhaust pipe 22 is sucked by utilizing the phenomenon of air pressure reduction caused by the ejector 27 formed in the Regardless of changes in the flow rate of exhaust gas flowing therein, the flow rate of exhaust gas introduced into the flow pipe 24 via the intake pipe 23 was always kept constant. Therefore, even if the rotational speed of the engine body 21 changes, the exhaust gas concentration in the flow pipe 24 does not change, so the exhaust gas is analyzed in response to the change in the rotational speed of the engine body 21. There was a problem that I couldn't do.

This idea was devised in consideration of the above circumstances, and its purpose was to reduce the overall size of the device, and to enable exhaust gas analysis to be performed in response to changes in the engine speed. The object of the present invention is to provide a sample extraction device.

An embodiment of this invention will be described below with reference to FIGS. 3 to 7. Figure 3 shows the schematic configuration of the entire exhaust gas sample extraction device.
3 is an engine body, and 32 is an exhaust pipe of this engine body 31. The exhaust pipe 32 is connected to the suction end of a dynamic pressure regulating pipe 33 for exhaust gas. The flow path area of this dynamic pressure adjustment pipe 33 can be adjusted as appropriate in proportion to the total displacement (exhaust gas flow rate) of the engine body 31 of the test engine. Furthermore, an exhaust gas suction section 35 is provided in a spaced-apart manner facing the discharge port 34 of the dynamic pressure adjustment pipe 33. This exhaust gas suction section 35 is formed by a suction reducer 36 and a suction blower 37, and is connected to the engine main body 31.
Most of the exhaust gas discharged from the exhaust pipe 32 and the dynamic pressure adjustment pipe 33 is transferred to the suction reducer 36.
The air is sucked into the suction blower 37 through the suction blower 37. Further, a suction end 39 of a sample probe 38 is disposed within the exhaust gas flow path between the dynamic pressure adjustment pipe 33 and the suction reducer 36 . The discharge end 40 of this sample probe 38 is a flow pipe (dilution tunnel) for diluting exhaust gas, which will be described later.
It is inserted in 41. Furthermore, the sample probe 38 has a large diameter cladding tube 4 as shown in FIG.
2 and a plurality of pipes 43a, 43b, and 43c disposed within the cladding tube 42, respectively. In this case, each pipe 43a, 43b, 43c
are formed by relatively long thin tubes, and each pipe 43a, 43b, 43c has a flow path resistance in the exhaust gas flow path between the dynamic pressure adjustment tube 33 and the suction blower 37. In comparison, extremely large flow path resistance occurs, so the exhaust gas flow rate in each pipe 43a, 43b, 43c is always maintained at a constant value regardless of changes in the rotational speed of the engine body 31. Further, this sample probe 38 consists of a first component 44 on the suction end 39 side shown in FIG. 5 and a second component 45 on the discharge end 40 side fixed to the flow pipe 41 as shown in FIG. The first and second components 4 are connected to each other via connecting members 46 and 47.
4 and 45 are connected. Furthermore, an opening/closing mechanism section 48 for opening and closing each of the pipes 43a, 43b, and 43c of the sample probe 38 is provided at an intermediate portion of the first component 44. This opening/closing mechanism section 48 is connected to each pipe 43 of the sample probe 38.
First, second and third solenoid valves 49a, 49b, 4 are respectively attached to the pipes 43a, 43b, 43c and open and close the respective pipes 43a, 43b, 43c.
9c. The opening and closing operations of these first, second, and third solenoid valves 49a, 49b, and 49c are controlled by a controller 50. This controller 50 includes a rotation speed detector 5 for detecting the rotation speed of the engine body 31.
1 is connected. Based on the detection signal from this rotation speed detector 51, the controller 5
0, the first, second, third solenoid valves 49a, 49b,
The opening/closing operation of 49c is performed. That is, for example, when the engine body 31 is held at a low rotation speed and the exhaust gas flow rate is relatively small, only the first solenoid valve 49a is operated to open, and when the engine body 31 is maintained at a medium rotation speed. If the range is reached, both the first and second solenoid valves 49a,
49b is opened and the engine main body 31 reaches a high rotation speed range, the first, second, and third solenoid valves 49a, 49b, and 49c are all switched to an open state. There is. Therefore, the number of pipes to be opened is controlled according to the rotational speed of the engine body 31, so that an exhaust gas sample with a flow rate approximately proportional to the exhaust gas flow rate of the engine body 31 is guided to the discharge end 40 of the sample probe 38. It's getting old. On the other hand, the flow pipe 41 is provided with a diffusion ejector 52 and a critical flow bench lily 53, and a suction blower 54 is connected to the bench lily 53 side. Air is drawn into the tube 41. Further, as shown in FIG. 7, the diffusion ejector 52 is formed with a small diameter constriction part 56, and the discharge end 40 of the sample probe 38 is inserted into this constriction part 56. In this case, each pipe 43a, 43b, 4 of the sample probe 38 is
The exhaust gas sample is rapidly diffused through any open piping of ejector 52 of 3c.
It is designed to be inhaled internally. Then, the air and the exhaust gas sample are mixed in the flow pipe 41, and the diluted exhaust gas sample is transferred to the bench lily 5.
It is now possible for the water to flow to the third side. Further, one end of an intake pipe 57 is inserted into the flow pipe 41 near the bench lily 53. The other end of the intake pipe 57 is connected to an exhaust gas analyzer 59 via a bag 58, and the exhaust gas analyzer 59 analyzes the components of the exhaust gas. Note that 60 is a particulate collection filter holder, and 61 is a constant sample flow rate controller and a gas analyzer.

Therefore, in the above configuration, most of the exhaust gas discharged from the engine body 31 through the exhaust pipe 32 and the dynamic pressure adjustment pipe 33 is sucked into the suction blower 37 via the suction reducer 36.
In this case, the dynamic pressure adjustment pipe 33 and the suction reducer 36
Sample probe 3 is located in the exhaust gas flow path between
8 suction ends are arranged, and a part of the exhaust gas flows through each pipe 43a, 43b,
43c. Each of these piping 43a,
43b and 43c are formed by relatively long thin tubes, and each pipe 43a, 43b has a relatively long length compared to the flow path resistance in the exhaust gas flow path between the dynamic pressure adjustment tube 33 and the suction blower 37. , 43c has become extremely large, so each pipe 43a, 4
The exhaust gas flow rate in 3b and 43c is the same as that of the engine body 3.
The first, second, and third solenoid valves 49a, 49a, 49a, 49a, 49b, 49a, 49a, 49a, 49a, 49a, 43b, 43c, 43c, 43c, 43c, 43c, and 43c are always kept at a constant value regardless of changes in the number of rotations of the piping 43a, 43b, 43c. 49b and 49c are provided, respectively, and the controller 50 controls the first, first and second ones in accordance with the rotational speed of the engine body 31.
The opening and closing operations of the second and third solenoid valves 49a, 49b, and 49c are controlled. Therefore, the number of pipes that are opened among the pipes 43a, 43b, and 43c in the sample probe 38 is controlled according to the rotation speed of the engine main body 31, and approximately
An exhaust gas sample having a flow rate proportional to the exhaust gas flow rate of is introduced to the discharge end of the sample probe 38. Furthermore, since the discharge end of the sample probe 38 is disposed within the diffusion ejector 52 of the flow tube 41, the air pressure generated when the air sucked into the flow tube 41 passes through the constricted portion 56 of the diffusion ejector 52 Due to the drop phenomenon, exhaust gas rapidly flows from the discharge end of the sample probe 38 into the flow pipe 4.
1. Therefore,
Each pipe 43a, 43b of the sample probe 38,
The flow rate of exhaust gas in 43c can be increased,
It is possible to quickly respond to changes in the rotational speed of the engine body 31, that is, changes in the exhaust gas flow rate. Furthermore, by changing the flow path area of the dynamic pressure adjustment pipe 33 in proportion to the total displacement of the engine body 31 of the test engine, the exhaust gas flow rate in each pipe 43a, 43b, 43c of the sample probe 38 can be adjusted. It is possible to maintain the same condition regardless of the difference in displacement between the test engines, and the air in the flow pipe 41 and the exhaust gas can be mixed under the same conditions. Therefore, it is advantageous in comparing data from a plurality of test engines having different total displacements, and control errors by the controller 50 can be reduced.

It should be noted that this invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of this invention.

As explained above, according to this invention, the sample probe is formed by a plurality of pipes, and the suction end of each of these pipes is disposed within the exhaust gas flow path of the engine body, and each pipe of the sample probe is An opening/closing mechanism is provided to open and close each of the sample probes, and the number of pipes to be opened in the sample probe is controlled according to changes in the rotational speed of the engine body 31, so that the exhaust gas sample proportional to the rotational speed of the engine body is transferred to the sample probe. Since it is taken out from the discharge end, it is possible to take out a part of the exhaust gas from the engine body, making the entire device more compact and allowing exhaust gas analysis to be performed in response to changes in the rotational speed of the engine body. be able to.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic configuration diagrams showing different conventional examples, FIGS. 3 to 7 show an embodiment of this invention, FIG. 3 is a schematic configuration diagram of the entire device, and FIG. The figure is a sectional view taken along the - line in Figure 3.
The figure is a schematic configuration diagram showing the opening and closing mechanism, FIG. 6 is a side view showing the second component of the sample probe, and FIG. 7 is a longitudinal sectional view showing the diffusion ejector. 31...Engine body, 32...Exhaust pipe (exhaust passage), 33...Dynamic pressure adjustment pipe (exhaust passage), 34...
...Discharge port, 35...Exhaust gas suction section, 38...Sample probe, 43a, 43b, 43c...Piping, 48...Opening/closing mechanism section, 50...Controller.

Claims (1)

[Scope of utility model registration request] It is formed by an exhaust passage that guides exhaust gas discharged from the engine body, an exhaust gas suction part provided in a spaced-apart manner opposite to the discharge port of this exhaust passage, and a plurality of pipes, each of which has a suction end connected to the A sample probe disposed in the exhaust gas flow path that is sent from the exhaust passage to the exhaust gas suction section, an opening/closing mechanism that opens and closes each pipe of the sample probe, and a mechanism that responds to changes in the rotational speed of the engine body. and a controller for controlling the number of pipes opened by the opening/closing mechanism and extracting an exhaust gas sample proportional to the rotational speed of the engine body from the discharge end of the sample probe. Sample extraction device.