TWI831330B - Exhaust system with catalytic converter - Google Patents

Abstract

An exhaust device with a catalytic converter, which includes an exhaust pipe group and a front catalytic converter. The exhaust pipe group includes an exhaust pipe with a smaller diameter, and a larger exhaust pipe located at the rear end of the exhaust pipe. For exhaust tail barrels with a diameter of After the front end of the air pipe is connected to the exhaust outlet of the engine cylinder head, the pre-catalytic converter is located closer to the engine exhaust outlet, so that the exhaust gas discharged from the exhaust outlet passes through the pre-catalyst at a higher temperature. The catalytic converter can quickly cause a thermal catalytic reaction by passing the higher temperature exhaust gas through the catalyst in the pre-catalytic converter, resulting in higher catalytic conversion efficiency, and a small pre-catalytic converter can be selected. to reduce costs.

Description

Exhaust system with catalytic converter

The present invention relates to an exhaust device for a fuel-powered motor vehicle, and in particular, to an exhaust device that can improve exhaust gas conversion efficiency.

At present, in order to make the exhaust gas emitted by the fuel engine of fuel-powered motorcycles, all-terrain vehicles (ATV), and automobiles comply with environmental regulations, an external exhaust pipe is connected to the exhaust outlet of the engine's cylinder head. The device is to install a catalytic converter in the exhaust tail barrel at the end of the exhaust pipe. Through the catalytic conversion effect of the catalyst in the catalytic converter on the exhaust gas, it can reduce the harmful exhaust gas emitted by the engine and benefit the environment. .

Although the aforementioned existing exhaust device can use the catalytic converter in the exhaust tail barrel of the exhaust pipe to provide a catalytic conversion mechanism for the exhaust gas emitted by the engine, the catalytic converter of the existing exhaust device has poor conversion efficiency. problem. Because the catalyst in the catalytic converter needs to be in a predetermined operating temperature environment to produce a catalytic reaction, and as the temperature increases, the catalytic conversion efficiency of the exhaust gas increases. The catalytic converter in the existing exhaust device is installed in the exhaust tail barrel at the end of the exhaust pipe. The front end of the exhaust tail barrel is connected to a section of the exhaust pipe body with a smaller diameter. Therefore, in the exhaust The position of the catalytic converter in the tail barrel is far from the exhaust outlet of the cylinder head of the engine. When the temperature of the exhaust gas discharged from the exhaust outlet of the cylinder head reaches the catalytic converter in the exhaust tail barrel, the temperature of the exhaust gas The lower temperature results in a slower catalytic reaction rate of the catalyst to the exhaust gas and poor catalytic conversion efficiency. Therefore, the catalytic converter installed in the exhaust tail barrel of the existing exhaust device usually uses a larger size. product, that is, the diameter of the catalytic converter is larger than the diameter of the trachea body of the exhaust pipe, in order to use a larger volume, high catalyst hole density catalytic converter to increase the internal catalyst coating amount to a predetermined level Reduce the emission of harmful substances in exhaust gas.

However, the structure of the aforementioned existing exhaust device in which a larger-sized catalytic converter is installed in the exhaust tail barrel of the exhaust pipe is still due to the distance between the catalytic converter in the exhaust tail barrel and the cylinder head of the engine. The exhaust outlet is located far away, the temperature of the exhaust gas received is low, and the catalytic reaction efficiency of the catalyst is relatively small, so the effect of reducing the emission of harmful substances in the exhaust gas is still not good. Moreover, the catalytic converter located in the exhaust tail barrel uses a product with a larger size and a high catalytic hole density. The catalyst contains precious metals such as platinum (Pt), palladium (Pd), and rhodium (Rh). The coating amount is also relatively large, so the overall cost of the catalytic converter installed in the exhaust tail barrel is relatively high.

The object of the present invention is to provide an exhaust device with a catalytic converter to solve the problem of poor exhaust gas conversion efficiency of the existing structure of installing a catalytic converter in the silencer tail section of the exhaust pipe of a fuel-powered locomotive.

In order to achieve the aforementioned objects, the present invention proposes an exhaust device with a catalytic converter, which is used to connect the exhaust outlet of the cylinder head of a fuel-type engine. The exhaust device includes: An exhaust pipe group, which includes an exhaust pipe and an exhaust tail barrel located at the rear end of the exhaust pipe. The diameter of the exhaust pipe is smaller than the barrel diameter of the exhaust tail barrel. The exhaust pipe includes A front pipe section and an extended pipe section located behind the front pipe section, and the front end of the front pipe section can be connected to the exhaust outlet; and A front catalytic converter is connected between the rear end of the front pipe section and the front end of the extended pipe section, and the diameter of the front catalytic converter is close to the pipe diameter of the front pipe section and adjacent to the exhaust outlet.

Through the creation of the overall structure of the exhaust device with a catalytic converter, when applied to fuel-powered motorcycles, it at least has the following functions: 1. Shorten the catalytic thermal catalysis time: This invention uses a pre-catalytic converter to be installed at the exhaust outlet adjacent to the engine cylinder head. Because the pre-catalytic converter is closer to the exhaust outlet, the input exhaust gas temperature It is relatively high, so the high-temperature exhaust gas input from the exhaust outlet into the pre-catalytic converter can cause the catalyst to quickly initiate a thermal catalytic reaction and shorten the thermal catalytic time of the catalyst. 2. Improve the catalytic conversion efficiency of the catalyst: Following the above, the present invention arranges the pre-catalytic converter at the exhaust outlet adjacent to the engine cylinder head, so that the catalyst can generate better heat in a high-temperature environment. Catalytic conversion effect. 3. Small-sized catalytic converter can be selected: Following the above, the present invention installs the pre-catalytic converter in the smaller-diameter exhaust pipe in the exhaust pipe group. Because the pre-catalytic converter The converter is close to the exhaust outlet of the cylinder head of the engine, and can allow higher temperature exhaust gas to pass through to produce better catalytic conversion effect. Therefore, a smaller size pre-catalytic converter that is equivalent to the diameter of the exhaust pipe can be selected. Excellent catalytic conversion effect can be achieved by using a smaller catalyst with a sparse catalytic hole density and a small amount of precious metal coating. A single front catalytic converter is combined with the existing one installed in the exhaust tail barrel. Compared with large-size catalytic converters, the present invention can replace the large-size catalytic converter in the existing exhaust tail barrel with a lower-cost pre-catalytic converter, thereby reducing costs.

The exhaust device with a catalytic converter of the present invention can further add a middle-stage catalytic converter between the extended pipe section of the exhaust pipe and the exhaust tail barrel, or add a rear-stage catalytic converter in the exhaust tail barrel. , or add a mid-stage catalytic converter and a rear-stage catalytic converter to the exhaust pipe group. The mid-stage catalytic converter and the rear-stage catalytic converter are both the same as the front-stage catalytic converter, which is a smaller catalytic converter. Converter, in this way, through the mid-stage catalytic converter or the rear-stage catalytic converter after the front-stage catalytic converter, it provides multi-stage catalytic conversion for the exhaust gas discharged from the cylinder head of the engine to achieve better catalytic conversion. efficacy.

As shown in FIGS. 1 to 6 , several preferred embodiments of the exhaust device with a catalytic converter of the present invention are disclosed. As can be seen from these drawings, the exhaust device includes an exhaust pipe. Group 1 and a front-stage catalytic converter 2 may further include a mid-stage catalytic converter 3 , or further include a rear-stage catalytic converter 4 .

As shown in Figures 1 to 6, the exhaust pipe group 1 includes an exhaust pipe 10 and an exhaust tail barrel 20. The exhaust pipe 10 includes a front pipe section 11 and an extension pipe section 12 located behind the front pipe section 11. The pipe diameter of the extension pipe section 12 is equivalent to the pipe diameter of the front pipe section 11. The exhaust pipe 10 can be connected to the exhaust port of the engine of the fuel-fired locomotive with the front end of the front pipe section 11. The exhaust tail barrel 20 is located on the exhaust pipe. At the rear end of the air pipe 10, the barrel diameter of the exhaust tail barrel 20 is larger than the pipe diameter of the exhaust pipe 10. The diameter and size of the exhaust pipe 10 and the exhaust tail barrel 20 are based on actual product requirements or with reference to existing exhaust. Set according to the product of tube group 1. The exhaust tail barrel 20 includes an air inlet end 201 and an exhaust end 202 respectively located at the front and rear ends. The rear end of the extended pipe section 12 of the exhaust pipe 10 can be directly or indirectly connected to the exhaust tail barrel 20 . Inlet end 201.

As shown in FIGS. 2 and 4 , the exhaust tail barrel 20 includes a barrel shell 21 , a partition 22 , an inner tube 23 , a back pressure pipe 24 and an air outlet pipe 25 . There is an inner barrel space in the barrel shell 21. The partition 22 is provided in the barrel shell 21 and divides the inner barrel space of the barrel shell 21 into a first space 211 and a second space 212 arranged in sequence from front to back. The inner pipe 23 is disposed in the barrel shell 21 and passes from the air inlet end 201 backward through the first space 211 to communicate with the second space 212. The back pressure pipe 24 is disposed in the partition 22 and communicates with the first space. 211 and the second space 212. The air outlet pipe 25 connects the first space 211 and the exhaust end 202 through the partition 22 and the second space 212.

As shown in the first preferred embodiment shown in Figures 1 and 2, the pre-catalytic converter 2 is connected between the rear end of the front pipe section 11 and the front end of the extended pipe section 12. The pre-catalytic converter 2 The diameter of the pre-catalytic converter 2 is close to the diameter of the front pipe section 11. The structure of the pre-catalytic converter 2 is known. For example, the pre-catalytic converter 2 includes a hollow shell and a hollow shell. The interior of the body is equipped with a porous component with many holes. The surface of the porous component is coated with catalysts made of precious metals such as platinum (Pt), palladium (Pd), rhodium (Rh), etc., and its specific structure is not mentioned here. Repeat.

The second preferred embodiment shown in Figures 3 and 4 is based on the first preferred embodiment shown in Figures 1 and 2. The extension pipe section 12 of the exhaust pipe 10 and the exhaust tail A mid-section catalytic converter 3 is added between the air inlet ends 201 of the barrel 20 . The front and rear ends of the mid-section catalytic converter 3 are respectively connected to the rear end of the extension pipe section 12 and the front end of the air inlet end 201 of the exhaust tail barrel 20 .

The exhaust pipe 10 of the exhaust pipe group 1 further includes a rear pipe section 13. The rear pipe section 13 is located behind the extended pipe section 12 and connected to the air inlet end 201 of the exhaust tail barrel 20, and at the rear end of the extended pipe section 12. A mid-section catalytic converter 3 is installed between the front end of the rear pipe section 13 and the extended pipe section 12 is indirectly connected to the exhaust tail barrel 20 through the mid-section catalytic converter 3 and the rear pipe section 13. The pipe diameter of the rear pipe section 13 is equal to The diameter of the extension pipe section 12 is similar. The diameter of the middle section catalytic converter 3 is close to the pipe diameter of the extension pipe section 12. The middle section catalytic converter 3 is substantially the same as the front catalytic converter 2 and has the same size. For a small catalytic converter, the specific structure of the middle catalytic converter 3 will not be described again here.

As shown in the third preferred embodiment shown in Figure 5, which is based on the first preferred embodiment shown in Figures 1 and 2, the rear end of the extended pipe section 12 of the exhaust pipe group 1 is connected to the exhaust pipe The air inlet end 201 of the tail barrel 20 is connected to a rear-stage catalytic converter 4 on the inner pipe 23 of the exhaust tail barrel 20, so that the inner pipe 23 connected to the air inlet end 201 is connected to the second stage through the rear-stage catalytic converter 4. In the space 212, the rear-stage catalytic converter 4 is substantially the same as the front-stage catalytic converter 2 and has the same size. The specific structure of the rear-stage catalytic converter 4 will not be described again here.

The fourth preferred embodiment shown in Figure 6 is based on the first preferred embodiment shown in Figures 1 and 2, and further makes the exhaust pipe group 1 further include a rear pipe section 13. The pipe section 13 is located behind the extended pipe section 12 and connected to the air inlet end 201 of the exhaust tail barrel 20, and a mid-section catalytic converter 3 is installed between the rear end of the extended pipe section 12 and the front end of the rear pipe section 13. The extended pipe section 12 The air inlet end 201 of the exhaust tail barrel 20 is indirectly connected through the middle catalytic converter 3 and the rear pipe section. The pipe diameter of the rear pipe section 13 is equivalent to the pipe diameter of the front pipe section 11 or the extended pipe section 12. The middle catalytic converter 3 The diameter of the catalytic converter is close to the diameter of the rear pipe section 13 and the extended pipe section 12. The middle catalytic converter 3 is substantially the same as the front catalytic converter 2 and has the same size; in addition, the inner pipe 23 of the exhaust tail barrel 20 is connected A rear-stage catalytic converter 4 is connected to the inner tube 23 of the air inlet end 201 and communicates with the second space 212 through the rear-stage catalytic converter 4. The rear-stage catalytic converter 4 is essentially the same as the front-stage catalytic converter 2. And the sizes are similar, that is, the front catalytic converter 2, the middle catalytic converter 3 and the rear catalytic converter 4 are all small catalytic converters. The middle catalytic converter 3 and the rear catalytic converter The specific structure of 4 will not be described again here.

The present invention is based on the aforementioned invention of the exhaust device with a catalytic converter. The front pipe section 11 of the exhaust pipe 10 is connected to the exhaust outlet of the cylinder head of the engine. During the engine starting process, a pre-catalyst is used. The converter 2 is installed at the exhaust outlet adjacent to the engine cylinder head. The pre-catalytic converter 2 is close to the exhaust outlet. The temperature of the exhaust gas passing through the pre-catalytic converter 2 is relatively high. The pre-catalytic converter 2 The high-temperature exhaust gas in 2 can cause the catalyst to quickly undergo a thermal catalytic reaction, shorten the thermal catalysis time of the catalyst, and allow the catalyst to achieve better thermal catalytic conversion effect in a high-temperature environment.

On the other hand, the present invention disposes the pre-catalytic converter 2 in the smaller diameter exhaust pipe 10 in the exhaust pipe group 1, because the pre-catalytic converter 2 is adjacent to the exhaust gas of the cylinder head of the engine. outlet, and can allow higher temperature exhaust gas to pass through to produce a better catalytic conversion effect, and then a smaller size pre-catalytic converter 2 equivalent to the diameter of the exhaust pipe 10 can be selected. Therefore, with a smaller size and Catalysts with sparser pore density and less precious metal coating can achieve excellent catalyst conversion effects.

As shown in the preferred embodiments shown in Figures 3 to 6, the present invention can further add a mid-section catalytic converter 3 between the extended pipe section of the exhaust pipe 10 and the exhaust tail barrel 20, or in the exhaust tail barrel 20, add a rear-stage catalytic converter 4, or add a middle-stage catalytic converter 3 and a rear-stage catalytic converter 4 to the exhaust pipe group 1, a middle-stage catalytic converter 3, a rear-stage catalytic converter 4, and a front-stage catalytic converter. The catalytic converter 2 can use a small catalytic converter with a smaller size. In this way, the mid-stage catalytic converter 3 or/and the rear-stage catalytic converter 4 are used after the front catalytic converter 2 to relay the engine. The exhaust gas discharged from the cylinder head provides multi-stage catalytic conversion to achieve better catalytic conversion efficiency.

1:Exhaust pipe group 10:Exhaust pipe 11: Front pipe section 12:Extended pipe section 13:Rear pipe section 20:Exhaust tail barrel 201:Inlet end 202:Exhaust end 21: barrel shell 211:First Space 212:Second Space 22:Partition 23:Inner tube 24: Back pressure pipe 25:Exit pipe 2: Pre-catalytic converter 3: Mid-section catalytic converter 4: Rear stage catalytic converter

Figure 1 is a schematic perspective view of an exhaust device with a catalytic converter according to a first preferred embodiment of the present invention. FIG. 2 is a schematic top plan view of the first preferred embodiment of the exhaust device with a catalytic converter shown in FIG. 1 . Figure 3 is a schematic perspective view of an exhaust device with a catalytic converter according to a second preferred embodiment of the present invention. FIG. 4 is a schematic top plan view of the second preferred embodiment of the exhaust device with a catalytic converter shown in FIG. 3 . Figure 5 is a schematic top plan view of an exhaust device with a catalytic converter according to a third preferred embodiment of the present invention. FIG. 6 is a schematic top plan view of the fourth preferred embodiment of the exhaust device with a catalytic converter shown in FIG. 1 .

1:Exhaust pipe group

10:Exhaust pipe

11: Front pipe section

12:Extended pipe section

20:Exhaust tail barrel

201:Inlet end

202:Exhaust end

2: Pre-catalytic converter

Claims (2)

An exhaust device with a catalytic converter, which is used to connect the exhaust outlet of the cylinder head of a fuel-type engine. The exhaust device includes: an exhaust pipe group, which includes an exhaust pipe and is located on the exhaust pipe. There is an exhaust tail barrel at the rear end of the pipe. The pipe diameter of the exhaust pipe is smaller than the barrel diameter of the exhaust tail barrel. The exhaust pipe includes a front pipe section, an extended pipe section located behind the front pipe section, and a pipe section located behind the front pipe section. There is a rear pipe section behind the extended pipe section. The pipe diameter of the rear pipe section is equal to the pipe diameter of the extended pipe section, and the front end of the front pipe section can be connected to the exhaust outlet. The front and rear ends of the exhaust tail barrel are respectively It is an air inlet end and an exhaust end, and the air inlet end of the exhaust tail barrel is connected to the rear end of the rear pipe section; a front catalytic converter is connected between the rear end of the front pipe section and the extended pipe section. between the front ends, and the diameter of the front catalytic converter is close to the pipe diameter of the front pipe section and adjacent to the exhaust outlet; a mid-section catalytic converter is installed between the rear end of the extended pipe section and the rear pipe section Between the front ends, the diameter of the middle catalytic converter is close to the diameter of the extended pipe section, and the middle catalytic converter is substantially the same as the front catalytic converter; and a rear catalytic converter is installed In the exhaust tail barrel and connected to the air intake end and the exhaust end, the rear catalytic converter is substantially the same as the front catalytic converter and has the same size. The exhaust device with a catalytic converter as described in claim 1, wherein the exhaust tail barrel includes a barrel shell, a partition, an inner pipe, a back pressure pipe and an air outlet pipe. There is an inner barrel space. The partition is located in the barrel shell and divides the inner barrel space into a first space and a second space arranged in sequence from front to back. The inner tube is located in the barrel shell and can The air inlet end passes backward through the first space and communicates with the second space. The back pressure pipe penetrates the partition and communicates the first space and the second space. The air outlet pipe passes through the partition and The second space connects the first space and the exhaust end; the rear catalytic converter is installed in the first space of the exhaust tail barrel and connected to the rear end of the inner pipe, and is connected to the air intake The inner tube at the end is connected to the second space through the rear-stage catalytic converter.

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