JPH04105925U - Automotive engine exhaust gas purification device - Google Patents

Abstract

(57) [Summary] [Purpose] To further improve engine emissions at low temperatures by effectively using an adsorption device that can adsorb unburned gas in exhaust gas. [Configuration] Exhaust pipe 3 extending from the exhaust port of the engine body 1
At least a heater-equipped catalyst 5 is interposed therein, and an adsorption device 4 capable of adsorbing unburned gas in the exhaust gas is interposed in the exhaust pipe 3 upstream of the heater-equipped catalyst 5.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to an exhaust gas purification device for an automobile engine.

0002

[Conventional technology]

In the exhaust system of automobile engines, underfloor catalysts such as three-way catalysts are used to purify harmful components such as unburned gas (HC), carbon monoxide (CO), and nitrogen oxides (NO _x ) in the exhaust gas. It has become common to be equipped with By the way, in order to efficiently and sufficiently purify exhaust gas with a catalyst, it is necessary to maintain the catalyst at a certain temperature or higher. Therefore, it has been difficult to purify exhaust gas, especially when the engine is at a low temperature, because it takes a certain amount of time for the catalyst to reach its activation temperature immediately after the engine is started. Therefore, in recent years, various methods have been developed to preheat the catalyst when the engine is at low temperature, such as by assembling a heater to the underfloor catalyst or adding a new catalyst with a heater separately from the underfloor catalyst.

0003

[Problem that the idea aims to solve]

However, even with exhaust gas purification equipment that uses a method that preheats the catalyst, Naturally, harmful components cannot be purified during the preheating time, and therefore the engine temperature decreases. Exhaust gas countermeasures at the time were still insufficient. Therefore, the purpose of this invention is to develop an adsorption device that can effectively adsorb unburned gas in exhaust gas. By using exhaust gas purification technology, you can further improve emissions when the engine is at low temperature. The objective is to provide a device for converting

0004

[Means to solve the problem]

In order to achieve the above object, the configuration of the present invention is to extend from the exhaust port of the engine body. A heated catalyst is installed in the exhaust passage, and the exhaust gas is placed in the exhaust passage upstream of the heated catalyst. An adsorption device capable of adsorbing unburned gas was installed, and the exhaust port of the engine body was An underfloor catalyst is interposed in the extending exhaust passage, and unused substances in the exhaust are passed through the exhaust passage upstream of the underfloor catalyst. It is characterized by having an adsorption device capable of adsorbing fuel gas and a catalyst with a heater installed in series. Ru.

[0005]

[Effect]

According to the above configuration, when the engine temperature is low, the heater-equipped catalyst and the underfloor catalyst reach the activation temperature. Until this point has reached the limit, unburned gas (HC) is adsorbed and held by the adsorption device. On the other hand, the engine warmed up and the heater catalyst and underfloor catalyst reached their activation temperature. At the same time, the adsorption equipment also becomes hot and releases the adsorbed unburned gas, but this is carried out downstream. It is purified using a heated catalyst or an underfloor catalyst.

[0006]

【Example】

An embodiment of the present invention will be described below based on the accompanying drawings. FIG. 1 shows the first embodiment of the present invention, in which an exhaust pipe is installed at the exhaust port of the engine body 1. An exhaust pipe 3 is connected through the exhaust pipe 2, and the exhaust pipe 3 is connected to the exhaust pipe 3 sequentially from the upstream side. This is an example in which an adsorption device 4 and a catalyst with a heater 5 are provided. The adsorption device 4 uses unburned gas (HC) in the exhaust gas as an adsorbent when the temperature is low. It is adsorbed and held with granular activated carbon, etc., and when the temperature exceeds a certain level (approximately 150℃ or higher), the It releases unburned gas. In addition, the heater-equipped catalyst 5 is This is a conventional method that pre-heats the catalyst. Therefore, according to this embodiment, when the engine temperature is low, the heater-equipped catalyst 5 has a sufficient activation temperature. Unburnt gas discharged before the temperature reaches the maximum temperature is retained in the adsorption device 4. engine When the temperature of the heater-equipped catalyst 5 reaches the activation temperature, the adsorption device 4 whose temperature has risen at the same time Unburned gas is released from the gas, but this is purified by the heated catalyst 5 on the downstream side. . As a result, unburned gas emissions are reduced when the engine is cold, resulting in better emissions. becomes. In addition, since the heating time of the heater-equipped catalyst 5 can be obtained, the preheating time can be obtained. It is possible to shorten the time required to load the battery and reduce the amount of battery discharge.

[0007] FIG. 2 shows a second embodiment of the present invention. This is an example in which an underfloor catalyst 6 such as a three-way catalyst is interposed in the exhaust pipe 3 located downstream of the catalyst 5. . According to this, emissions after warm-up are further improved by adding the underfloor catalyst 6. Become good. In this embodiment, if the conditions are met, the heater-equipped catalyst 5 is transferred to the adsorption device 4. It may be placed on the upstream side.

[0008] FIG. 3 shows a third embodiment of the present invention, in which the adsorption device in the embodiment of FIG. 2 is shown. 4 is provided, and a branch part on the upstream side of this bypass passage 7 is provided. This is an example in which a flow path switching valve 8 is provided. The flow path switching valve 8 controls the exhaust gas when the temperature of the adsorption device 4 reaches a predetermined temperature. Switching control is performed by the control unit 9 so as to guide it to the bypass passage 7. 10 in the diagram This is a temperature sensor that detects the temperature of the adsorption device 4. The control unit 9 also has a suction device. It is determined that the release of unburned gas has been completed based on the temperature of the station 4. According to this, while it is possible to purify exhaust gas at low temperatures, the adsorption device 4 is exposed to high-temperature gas, reducing its durability and preventing the adsorbent from burning. can be prevented. In addition, in this example, the determination of the release of unburned gas in the adsorption device 4 is based on the adsorption It goes without saying that a timer type or other means may be used instead of temperature detection in device 4. do not have. Furthermore, the underfloor catalyst 6 may be omitted.

[0009] FIG. 4 shows a fourth embodiment of the present invention, in which the bypass passage in the embodiment of FIG. 3 is shown. This is an example in which not only the adsorption device 4 but also the heater-equipped catalyst 5 is bypassed by the passage 7. According to this, in addition to protecting the suction device 4 after warm-up is completed, the suction device 4 The increase in exhaust resistance due to the intervention of the catalyst 5 with a motor is avoided, resulting in improved output during acceleration, etc. can be achieved.

0010 Note that the present invention is not limited to the above-mentioned embodiments, and may be applied without departing from the gist of the present invention. Various changes are possible.

[0011]

[Effect of the idea]

As explained above, according to the present invention, in addition to a catalyst with a heater, etc. in the exhaust passage, a low-temperature Since we have installed an adsorption device that can adsorb and hold unburned gas in the exhaust gas, This has the effect of further improving emissions at low temperatures.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 Engine body 3 Exhaust pipe 4 Adsorption device 5 Catalyst with heater 6 Underfloor catalyst

Claims (6)

[Scope of utility model registration request] Claim 1: A catalyst with a heater is interposed in the exhaust passage extending from the exhaust port of the engine body, and an adsorption device capable of adsorbing unburned gas in the exhaust is interposed in the exhaust passage upstream of the catalyst with the heater. Features: Exhaust gas purification device for automobile engines. Claim 2: An underfloor catalyst is interposed in the exhaust passage extending from the exhaust port of the engine body, and an adsorption device capable of adsorbing unburned gas in the exhaust gas and a catalyst with a heater are connected in series in the exhaust passage upstream of the underfloor catalyst. An exhaust gas purification device for an automobile engine, characterized in that an exhaust gas purification device is provided for an automobile engine. 3. The exhaust passage is provided with a passage that bypasses the adsorption device, and the upstream branch of the bypass passage is provided with a flow path switching valve that operates according to the engine operating state. 2. The exhaust gas purification device for an automobile engine described in 2. 4. The exhaust passage is provided with a passage that bypasses the adsorption device and the heater-equipped catalyst, and the upstream branch of this bypass passage is provided with a flow passage switching valve that operates according to the engine operating state. The exhaust gas purification device for an automobile engine according to claim 2. 5. The exhaust gas purification device for an automobile engine according to claim 2, wherein a catalyst with a heater is disposed in the exhaust passage upstream of the adsorption device. 6. The exhaust gas purification device for an automobile engine according to claim 1, wherein an underfloor catalyst is disposed in the exhaust passage downstream of the heater-equipped catalyst.