JPH04194309A - Exhaust gas remover apparatus for engine - Google Patents

Abstract

PURPOSE:To prevent generation of bad odor in specific operations and burn the adsorbed unburnt fire particles, by causing a controller to control a first opening/closing valve, a second opening/closing valve, and a flow control valve in response to the sensor signals from a first and a second temperature sensor. CONSTITUTION:A bypass pipe passage 17 is connected to exhaust pipe passage 13 positioning at the front and rear sides of a converter 16, and a filter chamber 19, which is filled with fibrous active carbon 18, is provided to the bypass passage 17. Further, a recovering pipe passage 24, which is intended to guide an exhaust gas, having flown out from the filter chamber 19, to an inlet of the converter 16, is provided in a manner that the passage 24 branches from the passage 17. The sensor outputs of first and second temperature sensors 31, 32 are connected to control inputs of a controller 33, the control outputs of which are connected to stepping motors 27 to 30. The exhaust gas is guided to the bypass passage 17 and has unburnt fire particles therein adsorbed by the active carbon 18 in the filter chamber 19. This prevents the generation of bad odor and causes burning of the unburnt fire particles adsorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for removing unburned particulates from exhaust gas of an engine, particularly a diesel engine.

[Prior Art] A catalytic converter is conventionally known as this type of device. This catalytic converter oxidizes carbon monoxide and hydrocarbons, which are unburned particulates such as fuel and oil in exhaust gas, and converts them into harmless carbon dioxide and water vapor, respectively.The oxidation catalyst is housed in a container and pipes into the exhaust pipe. It is located in the middle of the road. In addition, this catalytic converter uses a noble metal such as platinum or rhodium as an oxidation catalyst, and activates the reaction by spraying exhaust gas onto the noble metal to burn off unburned particulates that give off a bad odor.

[Problems to be Solved by the Invention] However, the above-mentioned catalytic converter has a low exhaust gas temperature when the engine speed is low and the load is low, such as during warm-up or during special work using an on-board crane. There was a problem in that the temperature did not rise and it was difficult for the catalyst to sufficiently burn unburned particulates such as hydrocarbons. As a result, unburned particulates were released into the atmosphere, potentially emitting a bad odor to the surrounding area.

An object of the present invention is to provide an exhaust gas removal device for an engine that can prevent the occurrence of bad odors during warm-up or during special work featuring a vehicle engine, and can burn off adsorbed unburned particulates. It's about doing.

[Means for Solving the Problems] The present invention provides an exhaust pipe line 1 connected to an exhaust manifold 12.
This is an improvement of an exhaust gas removal device for an engine, which is equipped with a catalytic converter 16 filled with a catalyst 14 for purifying exhaust gas.

Its characteristic configuration includes a bypass pipe 17 that bypasses the converter 16 and is connected to the exhaust pipe 13, and a filter chamber 19 provided in the bypass pipe 17 and filled with activated carbon 18.
, a recovery pipe 24 that branches the exhaust gas flowing out from the filter chamber 19 from the bypass pipe 17 and leads it to the inlet of the converter 16 , and an exhaust pipe 1 that leads the exhaust gas to the converter 16 .
3, a second on-off valve 22 provided in the recovery pipe 24, and a bypass pipe 17 provided in the bypass pipe 17 that guides the exhaust gas to the filter chamber 19. A flow rate adjustment valve 26 that adjusts the inflow amount, a first temperature sensor 31 that detects the temperature of the exhaust gas before it flows into the bypass pipe 17, and a second temperature sensor that detects the temperature of the exhaust gas that flows into the bypass pipe 17. 32, and a controller 33 that controls the first on-off valve 21, the second on-off valve 22, and the flow rate adjustment valve 26 based on detection signals from the first and second temperature sensors 31 and 32.

[Function] During warm-up operation or during special work featuring a vehicle engine, the controller 33 controls the multi-valves 21, 22, and 26 to guide the exhaust gas from the engine 11 to the bypass pipe 17, and exhaust gas by the activated carbon 18. Adsorbs unburned particulates in gas. In addition, the unburned particulates adsorbed on the activated carbon 18 are removed from the flow rate regulating valve 2.
6 is adjusted to maintain the inside of the filter chamber 19 at a predetermined temperature and allow the exhaust gas to pass through, thereby being desorbed from the activated carbon 18. This exhaust gas passes through the recovery pipe 24 and is combusted in the catalytic converter 16. It is processed.

[Example] Next, an example of the present invention will be described in detail based on the drawings.

As shown in FIGS. 1 and 2, a diesel engine 1
An exhaust manifold 12 is connected to the exhaust port 1, and an exhaust pipe line 13 is connected to the exhaust manifold 12. A catalytic converter 16 filled with a catalyst 14 for purifying exhaust gas is provided in the middle of the exhaust pipe 13. Exhaust pipe line 13 before and after converter 16 bypassing converter 16
A bypass conduit 17 is connected to the bypass conduit 17, and a filter chamber 19 filled with fibrous activated carbon 18 is provided in the bypass conduit 17. Further, a recovery pipe 24 is provided branching from the bypass pipe 17 to guide the exhaust gas flowing out from the filter chamber 19 to the inlet of the converter 16 .

The exhaust pipe line 13 that guides the exhaust gas to the converter 16 has a first
An on-off valve 21 is provided, and a second on-off valve 2 is provided in the recovery pipe 24.
2 is provided. Further, a flow rate regulating valve 26 is provided in the bypass pipe line 17 that guides the exhaust gas to the filter chamber 19, and a third on-off valve 23 is provided at the outlet of the bypass pipe line 17.

The regulating valve 26 is configured to regulate the amount of exhaust gas flowing into the filter chamber 19 . These valves are also driven by stepping motors 27-30.

The exhaust gas temperature before flowing into the bypass line 17 is detected by a first temperature sensor 31, and the temperature of the exhaust gas flowing into the bypass line 17 is detected by a second temperature sensor 32. Each detection output of the first and second temperature sensors 31 and 32 is connected to a control input of a controller 33, and the control output of the controller 33 is connected to the stepping motors 27-30.

The operation of the engine exhaust gas removal device configured as described above will be explained.

During warm-up or during special work featuring a vehicle engine, the first temperature sensor 31 detects a temperature of 200°C or less, and the second
The temperature sensor 32 detects a temperature below 150°C, and the controller 33 closes the first and second on-off valves 21 and 22 via the stepping motors 26 to 30 based on these detection signals as shown by the solid line in FIG. , the flow rate adjustment valve 26 is fully opened as shown by the solid line in FIG. 2, and the third on-off valve 23 is further opened. Exhaust gas containing unburned particulates at a temperature of 100° C. or lower is guided to a bypass pipe 17 as shown by the solid arrow in FIG.

Further, when the warm-up operation and the special work featuring the vehicle engine are completed and the vehicle is driven normally, the controller 33 operates the stepping motors 27 to 30 based on the detection signals of the first and second temperature sensors 31 and 32. The first and second on-off valves 21 and 22 are opened as shown by the broken lines in FIG. 1, the flow rate adjustment valve 26 is adjusted to the opening degree shown as the two-dot chain line in FIG. 2, and the third on-off valve 23 is closed. . Most of the exhaust gas from the engine 1'1 is guided to the catalytic converter 16 through the first on-off valve 21 as shown by the dashed arrow in FIG. 1, but some exhaust gas is guided to the bypass pipe 17. .

Since this exhaust gas is maintained at a temperature of about 150° C., unburned particulates adsorbed on the activated carbon 18 are desorbed and guided along with the exhaust gas through the recovery pipe 24 to the catalytic converter 16 where it is burned.

In the examples, fibrous activated carbon was used, but this is just an example, and honeycomb-shaped activated carbon may also be used.

Further, although the opening/closing valve and the flow rate regulating valve are driven by a stepping motor, the present invention is not limited to this, and a fluid actuator, a near solenoid, or the like may be used.

In addition, the numerical values of the exhaust gas temperature in the examples are just examples, and
It is not limited to this value.

Further, although the outlet of the bypass pipe is connected to the exhaust pipe, the exhaust gas may be directly released to the atmosphere without being connected to the exhaust pipe. In this case, the third on-off valve becomes unnecessary.

[Effects of the Invention] As described above, according to the present invention, a filter chamber filled with activated carbon is provided in the bypass line that bypasses the exhaust muffler, and the bypass line at the outlet of the filter chamber is connected to the inlet of the catalytic converter. A recovery pipe is provided branching off from the exhaust pipe, and the controller controls the first on-off valve, the second on-off valve, and the flow rate adjustment valve based on the detection signals of the first and second temperature sensors. During warm-up or during special work featuring a vehicle engine, the controller guides engine exhaust gas to the bypass pipe, and the activated carbon in the filter chamber adsorbs unburned particulates in the exhaust gas.

In addition, during normal driving, the controller adjusts the opening degree of the flow rate adjustment valve to maintain the filter chamber at a predetermined high temperature and allows the exhaust gas to pass through, thereby desorbing unburned particulates from the activated carbon. It is then burned in a catalytic converter.

As a result, it is possible to prevent the generation of bad odors during warm-up or during special operations that feature a vehicle engine, and to burn off adsorbed unburned particulates.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of main parts including an exhaust gas removal device for an engine according to an embodiment of the present invention. Figure 2 is an enlarged view of section A in Figure 1. 12: exhaust manifold, 13: exhaust pipe line, 14: catalyst, 16: catalytic converter, 17: bypass line, 18: activated carbon, 19: filter chamber, 21: first on-off valve, 22: second on-off valve, 24 : recovery pipe, 26 two flow rate adjustment valves, 31: first temperature sensor, 32: second temperature sensor, 33: controller. Figure 2

Claims (1)

[Claims] Exhaust pipe line (13) connected to exhaust manifold (12)
In an exhaust gas removal device for an engine, the engine exhaust gas removal device is equipped with a catalytic converter (16) filled with a catalyst (14) for purifying exhaust gas in the middle of the exhaust pipe (13), bypassing the converter (16).
); a filter chamber (19) provided in the bypass conduit (17) and filled with activated carbon (18); The converter (16) is branched from the bypass line (17).
) and a recovery pipe (24) leading to the inlet of the converter (
16), a first on-off valve (21) provided in the exhaust pipe line (13), a second on-off valve (22) provided in the recovery pipe line (24), and the filter chamber. (19) provided in the bypass pipe (17) for guiding exhaust gas to the exhaust gas filter chamber (19);
a first temperature sensor (31) that detects the temperature of the exhaust gas before it flows into the bypass pipe (17);
17), a second temperature sensor (32) that detects the temperature of the exhaust gas flowing into the exhaust gas, and a second temperature sensor (32) that detects the temperature of the exhaust gas flowing into the first on-off valve (21), 2 on-off valve (2
2) and a controller (
33) An exhaust gas removal device for an engine, characterized by comprising: