KR20040042177A - Catalystic Converter - Google Patents

Abstract

PURPOSE: A catalytic device for purifying the exhaust gas is provided to reduce air pollution caused by the exhaust gas of a vehicle by collecting harmful elements like hydrocarbon discharged concentratedly in starting the vehicle with an HC(Hydrocarbon)-absorber and then purifying and discharging the hydrocarbon with a catalyst reaching activation temperature after constant time. CONSTITUTION: A catalytic device for purifying the exhaust gas is composed of an HC-absorber(2) for collecting hydrocarbon and a catalyst(3) for reducing harmful elements mounted to the upper and lower parts in a case(1); a bypass tube(4) for forming a bypass exhaust passage bypassing the HC-absorber; an opening and closing plate(60) installed in the bypass exhaust passage to open and close the bypass exhaust passage; and an opening and closing device for discharging the exhaust gas through the bypass exhaust passage by opening the opening and closing plate if the temperature of the exhaust gas is over a constant value.

Description

Catalytic device for exhaust gas purification {Catalystic Converter}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purification catalyst device installed in an exhaust device of a vehicle in order to remove harmful components contained in exhaust gases emitted from the combustion engine and released into the atmosphere. It relates to an exhaust gas purification catalyst device configured to effectively purify harmful components.

In order to cope with the tougher regulations on automobile emissions, the exhaust gas purification catalyst installed in automobile exhaust system has been improved to remove more harmful components from the exhaust gas through precise electronic control and various exhaust gas aftertreatment. And as a result, emissions have been significantly reduced.

In the case of the catalyst which removes harmful constituents in the exhaust gas purification catalyst device, it is required to reach a certain level (activation temperature: about 350 C light-off temperature) for smooth purification. When the temperature of the catalyst unit exceeds the activation temperature and proper air-fuel ratio control, almost all harmful substances emitted from the engine are purified. However, since the temperature of the catalyst at the beginning of startup must receive heat from the exhaust gas in order to reach the activation temperature at the same level as the atmospheric temperature, from the start until the activation temperature is reached (20 ~ 30 seconds after the start of LA-4 mode) ) Hazardous gases are emitted as they are. The time is not too long, but the emissions emitted during this period exceed 80% of the total emissions. Therefore, many studies have been conducted to reduce the exhaust gas during cold start, and representative technologies include an electrically heated catalyst (EHC) method for heating a catalyst using an electric device, a method using a hydrocarbon-absorber, and the like. There is this.

In the case of the electric heating catalyst device (EHC), a heating wire is inserted into the catalyst device to heat the temperature of the catalyst by using the battery power, and it has a significant effect on reducing the emission gas during cold start. In addition to exceeding the capacity of the existing battery, as well as reducing the durability of the battery and significant factors that can not be applied to the actual situation. In the case of using the HC-Adsorber, the hydrocarbon discharged at the initial stage of cold start is collected in the hydrocarbon collecting device, and when the catalyst reaches a certain level, the collected hydrocarbons are flown to purify the catalyst at the rear. As a technique, this method is perfect for hydrocarbon capture in the early stage of cold start, but when the temperature of capture device is above 250 ℃, it starts to release the stored hydrocarbon. Since maintaining a much lower temperature than there was a problem that the hydrocarbon emitted from the collector is released without purification. Therefore, the method using the hydrocarbon absorber (HC-Adsorber) had a significant decrease in the utility value compared to the cost increase of about 20% compared to the existing technology. In order to alleviate this drawback, a method of purifying the hydrocarbons discharged from the collecting device by using a branch pipe to an upstream catalytic device has been proposed. However, this method has a problem that the exhaust system is complicated, and the risk of exhaust gas leakage is inevitable due to the valve controlling the flow in the branch pipe.

The present invention has been made in order to improve the problems of the conventional catalyst for purification of exhaust gas as described above, an object of the present invention is to provide a catalyst for purification of exhaust gas is configured to effectively reduce the hydrocarbon mainly generated at the beginning.

1 is a cross-sectional view of the initial starting operation of the catalyst for purification of exhaust gas according to an embodiment of the present invention.

Figure 2 is an enlarged cross-sectional view showing the bypass pipe and its opening and closing structure of the catalyst for purification of exhaust gas according to an embodiment of the present invention.

3 is a cross-sectional view of a normal operation of the catalyst for purifying exhaust gas according to an embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

1: Case 2: Hydrocarbon collector

3: catalyst 4: bypass tube

5: perforated plate 6: torsion spring

60: opening and closing plate 60a: rotation axis

61 cylinder 62 piston

63: torsion spring 64: wire

Exhaust gas purification catalyst device according to the present invention is a catalyst for exhaust gas purification equipped with a catalyst for reducing hydrocarbons (HC-Absorber) and other harmful components that can collect hydrocarbons on the inside and downstream of the case, respectively. And a bypass pipe forming a bypass exhaust path bypassing the hydrocarbon collector; An opening / closing plate installed in the bypass exhaust path to open and close the bypass exhaust path; And an opening / closing device which opens the opening / closing plate when the exhaust gas temperature is higher than a predetermined temperature so that the exhaust gas is exhausted through the bypass exhaust.

In the above configuration, the opening and closing device includes a cylinder for forming a thermal expansion chamber to fill the thermal expansion fluid expanded by the exhaust gas heat; And a piston for advancing by the thermal expansion chamber pressure of the cylinder to open the opening and closing plate connected to the front end thereof.

The opening and closing device may further include: a wire for closing the opening and closing plate by rotating the rotating shaft while being pulled by the piston when the piston is retracted by the negative pressure of the thermal expansion chamber while being wound around the rotating shaft of the opening and closing plate; It is preferable to include a; torsion spring for elastically supporting the opening and closing plate in the opening direction.

Hereinafter, the configuration and operation of the catalyst for purifying exhaust gas according to the present invention will be described in more detail with reference to preferred embodiments.

1 is a cross-sectional view illustrating an initial operation of an exhaust gas purification catalyst device according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view showing a bypass tube and an opening / closing structure of the catalyst device for exhaust gas purification according to an embodiment of the present invention. to be. 3 is a cross-sectional view of the normal operation of the catalyst for purification of exhaust gas according to one embodiment of the present invention.

As illustrated in FIG. 1, the catalyst for purifying exhaust gas according to an exemplary embodiment of the present invention collects hydrocarbons contained in exhaust gas on an upstream side of a case 1 and an inside of the case 1 to form an exhaust gas passage. A hydrocarbon collector 2, which is installed so that it can be installed, a catalyst for purifying harmful components other than hydrocarbons on the downstream side of the case 1, and an exhaust path which does not pass the hydrocarbon collector 2 in the hydrocarbon collector 2, is formed. Bypass pipe (3), hemispherical perforated plate (5) coupled to the rear end of the bypass pipe (3), opening and closing plate for opening and closing the exhaust passage in the bypass pipe (3) while rotating in the bypass pipe (3) 60) and a thermal expansion chamber 61a filled with a thermal expansion fluid as shown in FIGS. 1 and 2 as an opening / closing device 6 for opening the opening / closing plate 60 when the exhaust gas temperature is above a predetermined temperature. Cylinder 61, the thermal expansion Piston 62 forward and backward according to the pressure change, the wire 64 wound on the opening and closing plate rotation shaft 60a in a state connected to the piston 62 and both ends of the locking jaw of the opening and closing plate 60 It is composed of a torsion spring 63 and the like fixed to 60b and the locking jaw 4a of the case 1 to elastically support the opening and closing plate 60 in the opening direction.

In the above configuration, the opening and closing device 6 for opening and closing the bypass pipe 3 is contracted in the thermal expansion chamber 61a as shown in FIG. 1 at the start of the start of the exhaust gas temperature not yet reaching the normal temperature. As the wire 64 is pulled by the piston 62 backed by the negative pressure of the thermal expansion fluid, the opening and closing plate 60 is rotated by rotating the rotation shaft 60a of the opening and closing plate 60, thereby bypassing the bypass pipe 3. To close. When the temperature of the exhaust gas rises after a predetermined time after the start, as shown in FIG. 3, the thermal expansion fluid of the thermal expansion chamber 61a expands due to the heat of the exhaust gas to push the piston 62 out of the wire 64. ), The opening and closing plate 60, which was restrained by the wire 64 pulled by the piston 62, is rotated by the elastic force of the torsion spring 63 to open the bypass pipe 3. Then, when the engine is stopped and the temperature of the exhaust gas drops, the temperature of the catalyst decreases and the piston 62 and the wire 64 are pulled by the negative pressure generated while the thermal expansion fluid of the thermal expansion chamber 61a contracts, and the opening and closing plate rotation shaft is rotated. By rotating 60a, the bypass tube 3 is closed by the opening and closing plate 60.

By the operation of the opening and closing device 6 as described above, the exhaust gas purifying catalyst device according to an embodiment of the present invention, when the temperature of the exhaust gas does not reach the normal temperature, the contracted thermal expansion fluid causes negative pressure to the piston 62. As it acts, the piston 62 retracts to pull the wire 64 and the bypass tube 3 is closed by the opening and closing plate 60 rotated by the wire 64. Accordingly, the exhaust gas which has not reached the normal temperature passes through the hydrocarbon collector 2 and is discharged through the catalyst. In the process, the hydrocarbon contained in the exhaust gas is collected in the hydrocarbon collector 2 and other harmful components are purified by the catalyst. . Therefore, the start-up exhaust gas is discharged while most of the harmful components are removed while passing through the hydrocarbon collector 2 and the catalyst.

Subsequently, when the temperature of the exhaust gas rises for a predetermined time after the start-up, the hydrocarbon collector 2 is heated to reach a temperature (about 250 ° C.) at which the hydrocarbon is released, and the thermal expansion fluid of the thermal expansion chamber 61a is exhaust gas. The opening and closing plate 60, which was restrained by the wire 64 pulled by the piston 62 by inflating by the heat of swelling, pushes the piston 62 to the restoring force of the torsion spring 63 as the wire 64 loosens. It rotates to open the bypass pipe 3. Therefore, most of the exhaust gas is passed through the exhaust passage in the bypass pipe (3) without flow resistance, dispersed in the porous plate (5) and discharged through the entire surface of the catalyst, in the process, the exhaust gas is already exhausted in advance. Most of the harmful components and the hydrocarbon component released from the hydrocarbon collector 2 are discharged in a purified state by the catalyst heated sufficiently by the heat of the gas and raised above the activation temperature.

As described in detail above, the catalyst for purifying exhaust gas according to the present invention collects harmful components such as hydrocarbons intensively discharged at the beginning of a startup with a hydrocarbon collector and purifies with a catalyst that reaches an activation temperature after a certain time. This can greatly contribute to reducing air pollution caused by automobile emissions.

In addition, the catalyst device for purifying exhaust gas according to the present invention does not require a separate control device such as a branch pipe or a control valve, and can reduce the volume and precious metal content of the catalyst by improving the purification performance. Since the size of is reduced to reduce the back pressure has the effect of improving the power performance.

Claims (4)

In the catalyst device for purifying exhaust gas provided with a hydrocarbon collector and a catalyst for reducing other harmful components on the inside and downstream of the case, respectively, A bypass pipe forming a bypass exhaust path bypassing the hydrocarbon collector; An opening / closing plate installed in the bypass exhaust path to open and close the bypass exhaust path; And And an opening / closing device which opens the opening / closing plate when the exhaust gas temperature is higher than a predetermined temperature so that the exhaust gas is exhausted through the bypass exhaust passage. The method of claim 1, And a porous plate coupled to the rear end of the bypass pipe to disperse and permeate exhaust gas discharged from the bypass pipe in all directions toward the downstream side. The method according to claim 1 or 2, The opening and closing device includes a cylinder for forming a thermal expansion chamber to fill a thermal expansion fluid that is expanded by exhaust gas heat; And a piston for advancing by the thermal expansion chamber pressure of the cylinder to open the opening / closing plate connected to the front end thereof. The method of claim 3, wherein A wire for closing the opening and closing plate by rotating the rotating shaft while being pulled by the piston when the piston is retracted by the negative pressure of the thermal expansion chamber while being wound around the rotating shaft of the opening and closing plate; And A torsion spring for elastically supporting the opening and closing plate in the direction of opening; Catalyst for purification of exhaust gas comprising a.