KR100398226B1 - An exhaust manifold structure of engine - Google Patents

Abstract

The present invention relates to a structure of an exhaust manifold provided for exhausting exhaust gas generated from an automobile engine. In a four-cylinder engine, the first runner 11 and the second runner 12 form a shared section. The third runner 13 and the fourth runner 14 are joined to each other to form a shared end surface, and the downstream end portions of the first runner 11 and the second runner 12 and the third runner are joined to each other. The downstream ends of the 13 and fourth runners 14 are respectively joined to the upper central portion of the joint 15 of the cavity and connected to the exhaust pipe so that the exhaust gas is supplied to the catalyst with the heat loss of the exhaust gas minimized. By shortening the light off time of the catalyst and by enabling the catalytic converter to exhibit an efficient purification performance as soon as possible, the exhaust gas purification of the initial engine start can be more efficiently performed.

Description

Engine exhaust manifold structure {AN EXHAUST MANIFOLD STRUCTURE OF ENGINE}

The present invention relates to a structure of an exhaust manifold provided to exhaust exhaust gas generated from an automobile engine. More particularly, the light off time of the catalyst is greatly shortened by the improvement of the exhaust flow. It is about making it possible to significantly reduce the amount.

In general, an engine generates thermal energy by rotating a crankshaft through a connecting rod connected to the piston to explode force generated by burning fuel in a combustion chamber formed between a cylinder and a cylinder head and a piston reciprocating in the cylinder. It is a device that converts torque.

The engine requires an exhaust device for exhausting the combusted mixer. The exhaust device includes an exhaust pipe 50 connected to an exhaust manifold connected to the combustion chamber as shown in FIG. 1, and the exhaust pipe 50. It is composed of a catalytic converter 51 and a silencer 52 and the like connected.

Here, the exhaust gas passing through the exhaust device includes harmful substances such as hydrocarbons (HC), carbon monoxide (CO), nitrogen compounds (NOx), and sulfurous acid gas, and these harmful substances become the main causes of air pollution. As a result, the catalytic converter 51 is used as a device for purifying the harmful substances contained in the exhaust gas as described above, and the catalytic converter 51 is shown in FIG. As shown in FIG. 1, a mixture of platinum (Pt) and a small amount of rhodium (Rh) is attached to a catalyst carrier 53 installed inside the case to purify exhaust gas. Used for the oxidation of hydrocarbons, the rhodium is mainly used for the reduction of nitrogen compounds.

On the other hand, the catalytic converter 51 as described above generally does not exhibit sufficient performance until the temperature reaches a certain level, because in the actual engine, the light off time (LIGHT OFF TIME) is discharged so long This is because the gas is not purified properly and is discharged. Here, LIGHT OFF TIME refers to the time until the engine is initially started and the catalyst is fully functioning. It is also influenced by the flow of exhaust gas into the catalytic converter, i.e. the flow of exhaust gas depends on the shape of the exhaust manifold, and the difference in the initial heat loss of the exhaust gas varies according to the difference of the flow. Therefore, the light off time of the catalyst is affected. Meanwhile, FIGS. 3 to 5 show conventional general exhaust manifolds. 60 shows a conventional exhaust manifold 60, in which the first, second, third, and fourth runners 61, 62, 63, and 64 are spaced apart from each other, and the end portions of the conventional exhaust manifolds 60 are spaced apart from each other. The first and fourth runners 61 and 64 of the conventional exhaust manifold 60 are joined to the side portions of the joint 65, respectively. The second and third runners 62 and 63 are joined to the upper central portion of the junction 65. However, as described above, the first, second, third and fourth runners 61, 62, 63, The structure in which the 64 are spaced apart from each other and bonded to the joint 65 of the cavity has a large heat loss of the exhaust gas passing through the runners 61, 62, 63, and 64 at the initial start-up. Is not formed quickly, which leads to a long light off time, there is a problem that the purification of the exhaust gas is not efficient. In the conventional exhaust manifold 60, the runners 61, 62, 63, and 64 have a shape in which the ends of the runners 61, 62, 63, and 64 are joined while being widely distributed in the joint 65 of the cavity. (61, 62, 63, 64) is a structure in which the total connection surface area where the junction 65 is connected to each other is excessively large, and the amount of heat emitted from the surface of the junction 65 becomes large due to this structure. There was also a problem that the heat loss of the exhaust gas was increased. On the other hand, the first and fourth runners 61 and 64 of the runners 61, 62, 63 and 64 described above have the side surface of the junction 65 as described above. In order to be bonded toward the site, the curved portions 61a and 64a are inevitably formed in the middle. When the conventional curved portions 61a and 64a are formed in a substantially right angle as shown in FIG. As the gas passes through the bends 61a and 64a, the main flow of the runners 61 and 64 The wall or the inner wall surface of the junction 65 is severely hit, which causes a large heat loss through which the heat of the exhaust gas is not transferred to the catalyst smoothly, and in the end, the temperature of the catalyst is not increased rapidly. There was also a problem that the overall purification efficiency is lowered by not being able to.

Accordingly, the present invention has been made to solve all the above problems, and improves the structure of the exhaust manifold to shorten the light off time of the catalyst and at the initial start of the engine, the catalytic converter can exhibit efficient purification performance as soon as possible. It is an object of the present invention to provide an exhaust manifold structure of an engine so that exhaust gas purification can be more efficiently performed at the initial start of the engine.

1 is a structural diagram showing an exhaust device of a general engine,

2 is a structural diagram of a typical catalytic converter,

3 is a front view of the exhaust manifold according to the prior art,

4 is a plan view of FIG.

5 is a left side view of FIG. 3;

6 is a front view of the exhaust manifold according to the present invention;

7 is a plan view of FIG. 6;

8 is a left side view of FIG. 6.

<Description of Symbols for Main Parts of Drawings>

10-Exhaust manifold 11-1st runner 11a, 14a-Bend part 12-2nd runner 13-3rd runner 14-4th runner 15-Joint part of cavity

The exhaust manifold structure of the engine of the present invention for achieving the above object is joined to each other such that the first runner and the second runner form a shared section, and the third runner and the fourth runner form a shared section. And a downstream end portion of the first runner and the second runner and a downstream end portion of the third runner and the fourth runner are respectively joined to the upper central portion of the joint portion of the cavity and connected to the exhaust pipe. do.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

6 to 8 illustrate the exhaust manifold structure of the engine according to the present invention, and shows an exhaust manifold 10 that is configured to discharge exhaust gas discharged from a four-cylinder engine into one exhaust pipe and discharged. .

Exhaust manifold 10 of the present invention shown here to discharge the exhaust gas from the exhaust valves provided in each of the four combustion chambers through the first, second, third and fourth runners (11, 12, 13, 14), respectively. Here, among the runners 11, 12, 13, and 14, the first runner 11 and the second runner 12 are joined to each other to form a shared section, and the third runner is formed. 13 and the fourth runner 14 are also joined to each other so as to form a shared cross section to form the remaining pair. Further, downstream of the first runner 11 and the second runner 12 joined to each other. The side end portion and the downstream end portions of the third runner 13 and the fourth runner 14 are joined to each other at the center portion of the upper side of the surface of the joint portion 15 of the cavity. Predetermined portions of the first runner 11 and the second runner 12 are joined to each other to form a shared section, and predetermined portions of the third runner 13 and the fourth runner 14 are formed. When bonded to each other to form a shared cross-section, the total cross-sectional area of the runners (11, 12, 13, 14) according to the present invention is greatly reduced than the total cross-sectional area of the conventional individual runners (61, 62, 63, 64) This reduction in cross-sectional area not only makes it possible to significantly reduce the total heat loss of the exhaust gas passing through the runners 11, 12, 13 and 14 at the initial start-up, but also to activate the catalyst's activation temperature. By being able to form quickly, there is an effect that the light off time is shortened and the purification efficiency of the exhaust gas can be improved. Further, as described above, the exhaust manifold 10 according to the present invention has the respective runners. The ends of (11, 12, 13, 14) are gathered and joined to the upper central portion of the joint 15 of the cavity, and such a structure is a joint rather than the conventional structure described above with reference to Figs. Connection surface area of (15) is greatly reduced As a result, the amount of heat emitted from the surface of the junction 15 is greatly reduced, thereby reducing the overall heat loss of the exhaust gas, and the heat contained in the exhaust gas is transferred to the catalyst as much as possible, thereby activating the temperature of the catalyst. The first runner 11 and the fourth runner 11 located at the outermost of the runners 11, 12, 13 and 14 of the exhaust manifold 10 according to the present invention can be formed more quickly. 14, the bent portions 11a and 14a are formed, respectively, wherein the bent portions 11a and 14a have the first runner 11 and the fourth runner 14 at the upper central portion of the surface of the joint 15 of the cavity. Since the structure is bonded, it is not formed in a rectangular shape as shown in FIG. 4 but is formed in an arc-shaped curve as shown in FIG. 7. Thus, the first runner 11 and the fourth runner ( Curved portions 11a and 14a respectively formed in 14 are arc-shaped curves according to the present invention. When the exhaust gas passes through the bent portions 11a and 14a, the main flow thereof can be prevented from severely hitting the inner wall of the runners 11 and 14 or the inner wall surface of the junction 15. The heat loss through this can be minimized, so that the overall purification efficiency can be improved. In the engine to which the exhaust manifold 10 of the engine of the present invention configured as described above is applied, the exhaust gas discharged through the exhaust valve is provided. Moves through the runners 11, 12, 13, and 14 as described above, and transfers the heat to the runners 11, 12, 13, 14 and the junction 15 to a minimum, and these joints 15 Since the heat loss is minimized in comparison with the conventional method, the exhaust gas flowing into the catalytic converter via the exhaust pipe flows in the state containing as much heat as it had when discharged from the combustion chamber, thereby rapidly increasing the temperature of the catalyst. It can be raised.

Therefore, since the temperature of the catalyst reaches a state capable of normal catalytic activity within the shortest possible time from the start of the engine, there is an advantage that the purification efficiency of harmful components in the exhaust gas is greatly improved.

As described above, the present invention adopts a method of changing the shape of the exhaust manifold among various methods for delivering to the catalyst while minimizing heat loss of the exhaust gas. Unlike high-cost solutions such as SUS, for example, the catalyst converter is improved by shortening the catalyst's light off-time by improving the shape structure of the exhaust manifold at a cost that is almost the same as that of the conventional exhaust manifold manufacturing cost. By enabling efficient purification performance immediately, there is an effect that the exhaust gas purification in the initial stage of engine start can be more efficiently performed.

Claims (3)

In a four-cylinder engine, The first runner 11 and the second runner 12 are joined to each other to form a shared section, and the third runner 13 and the fourth runner 14 are joined to each other to form a shared section, and the first runner (11) and the downstream end of the second runner 12 and the downstream end of the third runner 13 and the fourth runner 14 are joined to the upper central part of the joint 15 of the cavity, respectively. Exhaust manifold structure of the engine, characterized in that configured to be connected to. delete According to claim 1, wherein the first runner 11 and the fourth runner 14 is formed with bent portions (11a, 14a), respectively, the bent portion (11a, 14a) is characterized in that formed in an arc-shaped curve Engine exhaust manifold structure.