KR20030018711A - cooler of exhaust gas recirculation - Google Patents

Abstract

PURPOSE: A cooler of an exhaust gas recirculation system is provided to improve an endurance of an EGR control valve and an engine by cooling recirculated exhaust gas. CONSTITUTION: A part of exhaust gas, which is discharged from an engine through an exhaust manifold, is recirculated into an intake manifold through an EGR pipe. An EGR control valve is mounted on a predetermined portion of the EGR pipe. An air cleaner is provided to purify air introduced into the intake manifold. A catalyst converter is provided to reduce harmful material contained in exhaust gas discharged from the exhaust manifold. A part of exhaust gas discharged from the exhaust manifold is recirculated into the intake manifold through the EGR pipe. The temperature of a mixer is lowered due to recirculated exhaust gas, thereby reducing an amount of NOx. A cooler(30) is mounted on the EGR pipe in order to lower the temperature of recirculated exhaust gas. The cooler(30) includes a housing(31) and a passage assembly(33) installed in the housing(31). An exhaust gas inlet pipe is installed at one side of the housing(31) and an exhaust gas outlet pipe(22) is installed at the other side of the housing(31).

Description

Cooler of exhaust gas recirculation

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooler of an exhaust gas recirculation apparatus, and more particularly, to a cooler of an exhaust gas recirculation apparatus capable of simultaneously increasing the thermal efficiency of the exhaust gas and the cooling efficiency of the exhaust gas.

In general, the exhaust gas of an automobile includes blow-by gas, in which a combustion chamber mixer or unburned gas leaks from an engine crankcase, fuel evaporation gas which is released into the atmosphere by evaporation of fuel in a fuel tank, Exhaust gas discharged to the exhaust system;

The vehicle exhaust gas contains harmful substances such as carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC), and the like, and nitrogen oxides are always opposed to carbon monoxide and hydrocarbons among the three elements generated during the combustion process. Has a causal relationship with

In other words, nitrogen oxides are most generated at the point where carbon monoxide and hydrocarbons are most reduced in the practical power range, and the nitrogen oxides are increased as fuel is completely burned, that is, the engine is hot.

The exhaust gas recirculation apparatus (hereinafter referred to as EGR) is a device that suppresses the generation of nitrogen oxides (NOx) by lowering the combustion temperature in the cylinder by recycling the exhaust gas of the exhaust gas to the intake system.

In other words, a part of the exhaust gas is returned to the intake cylinder as a means for reducing the nitrogen oxides (NOx) in the exhaust gas, so that the maximum temperature is lowered and the amount of nitrogen oxides (NOx) is reduced when the mixer burns.

This general configuration of the EGR, as shown in Figure 1, is a part of the exhaust gas discharged from the engine 1 through the exhaust manifold (2) is recycled to the intake manifold (4) through the EGR pipe (3). The EGR control valve 5 which adjusts an EGR amount is attached to the predetermined part of the said EGR pipe 3, and is comprised.

Here, reference numeral 6 shown in FIG. 1 denotes an air cleaner for purifying the air flowing into the intake manifold 4, and reference numeral 7 reduces the harmful substances of the exhaust gas discharged from the exhaust manifold 2. It shows a catalytic converter.

Accordingly, some of the exhaust gas of the exhaust gas discharged from the exhaust manifold 2 is recycled to the intake manifold 4 through the EGR pipe 3, and the recycled exhaust gas is burned by the mixer. At the same time, the maximum temperature is lowered to reduce the amount of NOx produced.

On the other hand, the EGR pipe 3 is equipped with a cooler 10 (hereinafter referred to as EGR cooler) for lowering the temperature of the exhaust gas recycled, the conventional configuration of the EGR cooler 10 is shown in Figs. As mentioned above, the both ends are comprised from the cylindrical housing 11 connected with the said EGR pipe 3, and the several pipe member 12 provided in the inside of this housing 11 is carried out.

Here, the inner space of the housing 11 is divided into three chambers 11a, 11b, and 11c by the plurality of diaphragm members 13 and 14, and the first plate member 13 and the second plate member 14 is installed in both sides of the housing 11 in the height direction, so that the inner space of the housing 11 is formed of the first, second, third chambers 11a, 11b, 11c.

Meanwhile, both ends of the pipe member 12 installed in the second chamber 11b of the housing 11 pass through the first and second plate members 13 and 14, respectively, to allow the first and third chambers 11a and 11c. In this case, the exhaust gas introduced into the first chamber 11a and collected therein is moved to the third chamber 11c through the pipe member 12 to be collected again, and the third chamber The exhaust gas collected in 11c) is recycled to the intake manifold 4 again through the EGR pipe 3.

In addition, the second chamber 11b is filled with cooling water for lowering the temperature of the exhaust gas moved through the pipe member 12, and the cooling water is supplied through the cooling water supply pipe 15 connected to the second chamber 11b. It is supplied and then discharged through the cooling water discharge pipe 16.

Accordingly, the exhaust gas recycled from the exhaust manifold 2 to the EGR pipe 3 is lowered as much as possible by the coolant in the course of passing through the housing 11 of the EGR cooler 10. The lowered exhaust gas is again supplied to the intake manifold 4 through the EGR pipe 3.

However, the conventional EGR cooler 10 is formed with a relatively small space of the size of the second chamber 11b in which the coolant exists compared to the number of the pipe members 12 through which the exhaust gas passes. Exhaust gas passes through the pipe member 12 in a state in which the exhaust gas is not sufficiently cooled, which adversely affects durability of the EGR control valve 5 and the engine 1.

Accordingly, the present invention has been devised to solve the above problems, and it is possible to extend the contact time while increasing the area where the exhaust gas recycled through the EGR pipe is in contact with the cooling water, thereby sufficiently increasing the temperature of the exhaust gas being recycled. In addition to cooling, the object of the present invention is to provide a cooler of the exhaust gas recirculation device that can improve the durability of the EGR control valve and the engine.

The present cooler for achieving the above object, the exhaust gas inlet pipe is installed on one side so that the exhaust gas is recycled through the EGR pipe in the exhaust manifold and the exhaust gas discharge for exhausting the exhaust gas to the EGR pipe on the other side As the pipe is installed, a coolant supply pipe for supplying coolant is installed on one surface in a direction orthogonal to the exhaust gas inlet / exhaust pipe, and a housing on which a coolant discharge pipe for discharging the supplied coolant is installed, and exhaust gas The exhaust gas passage hole passing through and the cooling water passage hole passing through the coolant are integrally provided in a direction perpendicular to each other, and a passage assembly installed in the housing such that each chamber is formed inside the housing connected to the pipes. It is characterized in that the configuration.

1 is a schematic configuration diagram of a general exhaust gas recirculation device (EGR),

2 and 3 are a perspective view and a partial longitudinal cross-sectional view for explaining a conventional cooler,

4 is a perspective view for explaining a cooler according to the present invention;

5 is a partial cross-sectional view taken along line II of FIG. 4;

6 is an enlarged view illustrating main parts of FIG. 5 for describing an exhaust gas passage;

FIG. 7 is a partial cross-sectional view taken along line II-II of FIG. 4.

<Description of Symbols for Main Parts of Drawings>

1-Engine 2-Exhaust Manifold

3-EGR Pipe 4-Intake Manifold

21-exhaust gas inlet pipe 22-exhaust gas outlet pipe

23-Cooling water supply pipe 24-Cooling water discharge pipe

30-Cooler (EGR cooler) 31-Housing

31a, 31b, 31c, 31d-Chamber 33-Passage Assembly

33a-exhaust gas passage hole 33b-projection

33c-coolant through hole

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

Figure 4 is a perspective view for explaining the cooler according to the present invention, will be described with the same reference numerals to the same parts as the conventional structure.

The cooler, or EGR cooler, according to the present invention has a structure provided on an EGR pipe constituting an exhaust gas recirculation apparatus (EGR).

That is, in the general configuration of the EGR, as described above with reference to FIG. 1, a part of the exhaust gas discharged from the engine 1 through the exhaust manifold 2 is transferred to the intake manifold 4 through the EGR pipe 3. ), And a predetermined portion of the EGR pipe 3 is equipped with an EGR control valve 5 for adjusting the EGR amount.

Here, reference numeral 6 shown in FIG. 1 denotes an air cleaner for purifying the air flowing into the intake manifold 4, and reference numeral 7 reduces the harmful substances of the exhaust gas discharged from the exhaust manifold 2. It shows a catalytic converter.

Accordingly, some of the exhaust gas of the exhaust gas discharged from the exhaust manifold 2 is recycled to the intake manifold 4 through the EGR pipe 3, and the recycled exhaust gas is burned by the mixer. At the same time, the maximum temperature is lowered to reduce the amount of NOx produced.

On the other hand, the EGR pipe 3 is equipped with a cooler 30 according to the present invention for reducing the temperature of the exhaust gas recycled (hereinafter referred to as EGR cooler), the EGR cooler 30 is shown in FIGS. As shown in the figure, the housing 31 and the passage assembly 33 installed in the housing 31 are large.

Here, an exhaust gas inflow pipe 21 is installed on one surface of the housing 31 so that the exhaust gas recycled through the EGR pipe 3 from the exhaust manifold 2 is introduced, and this exhaust gas inflow pipe 21 is provided. The other side of the housing 31 opposite to the structure is provided with an exhaust gas exhaust pipe 22 for discharging the exhaust gas from the housing 31 to the EGR pipe 3.

In addition, one surface of the housing 31 having a direction orthogonal to the exhaust gas inlet / outlet pipes 21 and 22 is provided with a cooling water supply pipe 23 through which cooling water is supplied, and the cooling water supply pipe 23 and The other surface of the opposite housing 31 is provided with a cooling water discharge pipe 24 for discharging the cooling water supplied to the housing 31 to reduce the temperature of the exhaust gas.

In addition, the passage assembly 33 installed inside the housing 31 is generally formed in the shape of a hexahedron, which faces one side toward the exhaust gas inflow pipe 21 and toward the exhaust gas exhaust pipe 22. The other surface is connected to each other through the exhaust gas passage hole 33a passing through the inside.

Here, the exhaust gas passage hole (33a) is formed in a plurality of stacking structure according to the height of the passage assembly 33.

In addition, the passage assembly 33 has a structure in which not only the exhaust gas passage hole 33a is formed but also the cooling water passage hole 33c.

That is, one surface facing the cooling water supply pipe 23 and the other surface facing the cooling water discharge pipe 24 are connected to each other through the cooling water passage hole 33c passing through the inside.

Here, the coolant passage hole 33c is formed to pass through the surface between the exhaust gas passage hole 33a.

On the other hand, when the passage assembly 33 is installed in the housing 31, four chambers 31a, 31b, 31c, 31d are usually formed inside the housing 31, and the exhaust gas inlet pipe 21 The chamber 31a formed at the side is a chamber 31a for collecting the exhaust gas flowing into the housing 31, and the chamber 31b formed at the exhaust gas discharge pipe 22 is the EGR through the housing 31. A chamber 31b for collecting the exhaust gas discharged toward the pipe 3, and a chamber 31c formed on the cooling water supply pipe 23 is a chamber 31c for collecting the coolant flowing into the housing 31. The chamber 31d formed at the cooling water discharge pipe 24 is a chamber 31d for collecting the cooling water discharged to the outside through the housing 31.

In addition, a plurality of protrusions 33b are formed in the exhaust gas passage hole 33a to increase the thermal area of the exhaust gas by increasing the contact area with the passage hole 33a when the exhaust gas passes. 33b) is formed in the shape of a comb pattern that does not disturb the flow of the exhaust gas, and is formed at portions spaced at regular intervals along the entire length of the exhaust gas passage hole 33a.

In addition, the coolant passage hole 33c is formed in the shape of a zigzag fin to increase the contact area between the exhaust gas and the coolant and to extend the contact time.

Therefore, when the EGR cooler 30 according to the present invention is installed on the EGR pipe 3, the exhaust gas introduced into the housing 31 through the exhaust gas inflow pipe 21 is exhausted from the passage assembly 33. While passing through the gas passage hole 33a, the contact area is increased by the comb-shaped protrusion 33b, and thus, the exhaust gas passes through the state where the contact area with the exhaust gas passage hole 33a is increased. When it is possible to increase the thermal efficiency of the overall exhaust gas by that much, it is possible to promote the performance improvement of the engine (1).

In addition, when the EGR cooler 30 according to the present invention is installed on the EGR pipe 3, the cooling water introduced into the housing 31 through the cooling water supply pipe 23 is formed in the passage assembly 33 formed in a pin shape. The coolant passage hole 33c of the coolant passes longer than the conventional pipe member 12 described above with reference to FIG. 3.

As such, when the passage time of the cooling water becomes longer, the contact time between the exhaust gas passing through the exhaust gas passage hole 33a and the cooling water passing through the cooling water passage hole 33c can be increased, and the contact area is also increased. Since it is possible to increase, the temperature of all the exhaust gas passing through the EGR cooler 30 according to the present invention is lowered to the optimum temperature and then discharged to the EGR pipe 3, which causes the EGR control valve 5 Not only can the durability of the engine be improved, but the performance of the overall engine 1 can be improved by that much.

As described above, according to the present invention, since the exhaust gas introduced into the housing through the exhaust gas inlet pipe passes through the exhaust gas passage hole of which the contact area is increased, the overall thermal efficiency of the exhaust gas is improved, and the passage time of the cooling water. This extended cooling water passage hole increases the contact time between the exhaust gas and the cooling water, thereby reducing the temperature of the exhaust gas to an optimal state, thereby improving the durability of the EGR control valve and improving the overall engine performance. Become effective.

Claims (5)

An exhaust gas inlet pipe 21 is installed on one surface to allow the exhaust gas recycled through the EGR pipe 3 to the exhaust manifold 2, and an exhaust gas discharge for exhausting the exhaust gas to the EGR pipe 3 on the other side. While the pipe 22 is installed, a coolant supply pipe 23 through which coolant is supplied is installed on one surface in a direction orthogonal to the exhaust gas inlet / outlet pipes 21 and 22, and the other surface is configured to discharge the supplied coolant. The housing 31 in which the cooling water discharge pipe 24 is installed, the exhaust gas passage hole 33a through which the exhaust gas passes, and the cooling water passage hole 33c through which the coolant passes, are integrally provided to have a direction perpendicular to each other. The passage assembly 33 is installed in the housing 31 so that the respective chambers 31a, 31b, 31c, and 31d are formed inside the housing 31 connected to the pipes 21, 22, 23, and 24. Cooler of exhaust gas recirculation system constituted. The cooler of claim 1, wherein the passage assembly (33) is formed in the shape of a cube. The exhaust gas passage hole 33a is formed in plural and has a structure stacked in the height direction of the passage assembly 33, and the cooling water passage hole 33c is formed in the exhaust gas passage hole 33a. Cooler of the exhaust gas recirculation device characterized in that the direction perpendicular to and penetrates the surface between the exhaust gas passage hole (33a). The exhaust gas passage hole (33a) has a shape of a comb pattern so that the plurality of protrusions (33b) for increasing the thermal efficiency by increasing the contact area of the exhaust gas so as not to disturb the flow of the exhaust gas Cooler of the exhaust gas recirculation device characterized in that the spaced apart at regular intervals along the length of the hole. The exhaust gas recirculation according to claim 1, wherein the coolant passage hole (33c) is formed in the shape of a zigzag fin to increase the contact time while increasing the contact area between the exhaust gas and the cooling water. Cooler of the device.