KR20090103405A - EGR cooler for automobile - Google Patents

Abstract

PURPOSE: An EGR cooler for a car is provided to increase thermal transfer efficiency of the EGR cooler. CONSTITUTION: An EGR cooler for a car comprises inlet ports(11a,11b), an inlet channel part(10), a gas channel part(20), a gas tube part(30) and an external housing part(40). The exhaust gas is flowed in into the inlet ports. An outlet port is formed on the top of the inlet channel part. The gas channel part is comprised of the form of a hollow. A gas passage is included inside the gas channel part. The gas passes through the gas passage. A cooling fluid passage is formed between the gas passages of the gas channel part. The cooling water passes through the cooling fluid passage. A cooling fluid entrance(42) and a cooling fluid exit(43) are formed outside of a housing.

Description

EBR cooler for automobile {EGR cooler for automobile}

The present invention relates to an automotive EGR cooler for cooling high-temperature exhaust gas using an engine cooling water as a refrigerant, and more particularly, to an automobile including a flow path structure of a gas and a cooling fluid capable of increasing the heat transfer efficiency of the EGR cooler. It's about the EGR cooler.

In general, the exhaust gas of automobiles contains harmful substances such as carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC), and the like. There is always a reverse causal relationship.

That is, nitrogen oxides are most generated when carbon monoxide and hydrocarbons are most decreased in the practical output range. The nitrogen oxides are increased as the fuel is completely burned, that is, the engine is hot.

Accordingly, as the allowable amount of the exhaust gas such as nitrogen oxide is regulated as a related law, various technologies for reducing the exhaust gas have been developed, and one of them is an exhaust gas recirculation (EGR).

The exhaust gas recirculation apparatus (EGR) supplies a portion of the combustion gas (EGR gas) to the mixer sucked into the combustion chamber while maintaining the mixing ratio at the theoretical air-fuel ratio in order to reduce the generation amount of nitrogen oxides without surging other harmful substances. It is a device used to reduce the temperature of flame by reducing the heat capacity of combustion gas at the same time.

More specifically, the exhaust gas recirculation apparatus is a device for reducing the combustion temperature in the cylinder to suppress the generation of nitrogen oxides by recycling the exhaust gas in the exhaust gas to the intake machine, and reduces the nitrogen oxides (NOx) in the exhaust gas. By means of returning a part of the exhaust gas to the intake cylinder, the maximum temperature is lowered when the mixer is burned to reduce the amount of nitrogen oxides (NOx) produced.

The exhaust gas recirculation apparatus includes an EGR pipe which allows a part of the exhaust gas discharged from the exhaust manifold to be recycled to the intake manifold, and a control valve for controlling the amount of exhaust gas circulated at a predetermined position of the EGR pipe. In particular, it includes an EGR cooler for cooling the exhaust gas flowing through the control valve to the intake manifold.

In the configuration of such an exhaust gas recirculation apparatus (EGR), the EGR cooler is a type of heat exchanger that cools exhaust gas of high temperature using engine cooling water as a refrigerant.

However, the conventional EGR cooler forms an exhaust gas passage using a SUS series pipe or plate product for cooling the exhaust gas.

In addition, in order to combine the plurality of exhaust gas passages and the cooling water passages, a shape is implemented by using a brazing method.

The bonding method using such brazing has poor appearance quality, and thus, there is a possibility of cooling water and exhaust gas leakage when assembling the EGR cooler, and the manufacturing process is complicated.

In addition, since the pipe and the plate mainly made of SUS material should be configured as the exhaust gas passage has a limitation in the shape implementation.

Therefore, the present invention has been invented to solve the above problems, while precisely casting the gas passage and the cooling fluid passage using an aluminum die casting method, the gas passage and the cooling fluid passage integrally formed in the gas channel portion and the gas EGR cooler for automobile that can increase the heat capacity of exhaust gas by forming a fin to increase the contact area with exhaust gas inside the passage, and at the same time, reduce the product weight, improve the degree of freedom of shape and appearance quality. To provide.

In order to achieve the above object, the present invention provides an inlet channel portion having two inlets 11a and 11b through which exhaust gas is introduced into a side surface of an EGR cooler for automobiles, and a single outlet 13a on an upper side thereof. 10); The gas channel part is formed in a hollow form, and a gas passage 23 through which gas can pass, and a cooling fluid passage 24 through which cooling water can pass between the gas passage 23 are integrally formed with each other ( 20); A gas tube part 30 having a rounded inner surface of a 'U' shape that is bent from bottom to top; The gas channel part 20 and the gas tube part 30 are accommodated and mounted therein, and include an outer housing part 40 having a cooling fluid inlet 42 and a cooling fluid outlet 43 formed therein. It is characterized by being configured to enable precision casting through the aluminum die casting method.

In a preferred embodiment, the inlet (11b) provided on one side of the inlet (11a, 11b) is recycled through the gas channel portion 20, gas tube portion 30 to the outside through the outlet (13a) It is provided with a recirculation route that is discharged, the inlet 11a provided on the other side is characterized in that it has a route that is discharged directly through the discharge port (13a).

The gas passage 23 is characterized in that a plurality of fins (23c) is provided to increase the contact area of the exhaust gas therein.

In addition, the cooling fluid passage 24 is characterized in that partitions 22a and 22b for changing the moving direction of the cooling fluid are installed in the inner space thereof.

The gas tube part 30 is characterized in that a plurality of guide members 31 are arranged on the surface of the inner surface of the rounding at regular intervals in parallel in the exhaust gas traveling direction.

In addition, each of the first to third flanges 12, 21, and 41 formed at one side of the inlet channel part 10, the gas channel part 20, and the outer housing part 40 is provided with a fastening means. It is characterized in that the fastening fixed by the media.

As described above, according to the automotive EGR cooler according to the present invention, the gas passage in the gas channel unit is implemented integrally with the cooling fluid passage, the gas flowing in the gas passage and the cooling fluid outside the gas passage Sufficient thermal contact is made between the cooling fluid flowing through the passage, thereby increasing the heat transfer efficiency, thereby improving the performance of the EGR cooler as a whole.

1 is an exploded perspective view showing an EGR cooler for an automobile according to the present invention;

2 is a cross-sectional view showing an EGR cooler for automobiles according to the present invention;

3 is a perspective view showing a gas channel portion of an EGR cooler for automobiles according to the present invention;

4 and 5 are a plan view and a bottom view showing a gas channel portion of the EGR cooler for automobiles according to the present invention,

6 is a cross-sectional view showing a gas channel portion of an EGR cooler for automobiles according to the present invention;

7 is a perspective view showing the inner surface of the gas tube portion of the EGR cooler for automobiles according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: inlet channel portion 11a, 11b: inlet

12: first flange 13a: outlet

20: gas channel portion 21: second flange

22a, 22b: bulkhead 23: gas passage

23a: gas inflow passage 23b: gas discharge passage

23c: pin 24: cooling fluid passage

30 gas tube part 31 guide member

32: projection member 40: outer housing portion

41: third flange 42: cooling fluid inlet

43: cooling fluid outlet 44: groove

Hereinafter, the configuration of the present invention with reference to the accompanying drawings in detail.

1 is an exploded perspective view showing an EGR cooler for an automobile according to the present invention, FIG. 2 is a sectional view showing an EGR cooler for an automobile according to the present invention, and FIG. 3 is a gas channel part of the EGR cooler for an automobile according to the present invention. It is a perspective view showing.

4 to 6 are a plan view, a bottom view, and a cross-sectional view showing a gas channel portion of an EGR cooler for automobiles according to the present invention.

The automotive EGR cooler according to the present invention is composed of an inlet channel part 10 having an exhaust gas inlet and an outlet, a gas channel part 20, a gas tube part 30, and an outer housing part 40, respectively. It is precision cast using aluminum die casting method.

The inlet channel part 10 has two inlets 11a and 11b through which exhaust gas flows into a side surface, and a single outlet 13a is formed on an upper side of the inlet channel part 10. Exhaust gas introduced into the inlet (11b) provided in the recirculated through the gas channel unit 20, gas tube unit 30 for heat exchange to secure a route discharged to the outside through the discharge port (13a), Exhaust gas introduced into the inlet (11a) provided on the side is secured a route discharged directly to the outlet (13a) without heat exchange.

That is, the exhaust gas flowing into the inlet port 11b located at the bottom is connected to the route for heat exchange, while the exhaust gas flowing into the inlet port 11a located at the top is connected to the route immediately discharged without heat exchange.

If the exhaust gas is discharged through the outlet 13a immediately without passing through the inside of the EGR cooler, the recycle exhaust gas does not pass through the EGR cooler (by-pass), so the engine is warmed up in a short time in the initial cold start state. (warm-up)

Therefore, there is an effect that can be reached within a short time as a temperature condition for optimizing the engine output characteristics.

The gas channel part 20 is formed in a hollow shape, and a gas passage 23 through which gas can pass is formed therein, and a cooling fluid passage through which the coolant passes through the gas passage 23. 24) is formed.

As shown in FIG. 6, a plurality of fins 23c are preferably applied to the inside of the gas passage 23 to increase the heat capacity by increasing the contact area of the exhaust gas.

At this time, since the pressure loss of the exhaust gas passing through the EGR cooler is changed depending on the number and shape of the fins 23c, the design ability to select the number and shape of the fins 23c that can increase the heat capacity while minimizing the pressure loss. need.

Therefore, the exhaust gas passing through the gas passage 23 is cooled while being in contact with the cooling fluid passage 24 cooled by the cooling fluid.

As shown in FIG. 3, the gas passages 23 are horizontally partitioned on one side of the gas channel unit 20, and a plurality of the gas passages 23 are arranged at regular intervals and are formed in a slot-hole shape in the longitudinal direction. The bar is divided into a lower gas inflow passage 23a and an upper gas discharge passage 23b.

More specifically, as shown in Figs. 4 and 5, a plurality of gas passages 23 of the gas channel portion 20 are arranged in a straight line through the gas, the gas in the traveling direction of the exhaust gas The diameter of the passage 23 decreases and then increases.

At this time, the smallest diameter in the diameter of the gas passage 23 is the central portion of the gas passage 23, the diameter gradually increases toward both ends of the gas passage 23.

To explain the above reasons, when the shape of the gas passage 20 of the gas channel portion 20, the die is inserted in the aluminum die casting method, the shape of the core is implemented to improve the extractability when extracting the core In order to have a subtractive gradient (gradient angle) for this, a change in the cross-sectional diameter occurs, and if the gas passage 23 is formed using a single core in the case of the same length and gradient angle, Therefore, since the passage length is doubled compared to using two cores, the minimum cross-sectional area of the gas passage 23 is relatively small, which causes a problem that the pressure loss of the exhaust gas is further increased.

Therefore, when two cores are used, the minimum cross-sectional area of the gas passage 23 can be increased than using a single core, and the exhaust gas pressure loss can be reduced, thereby improving engine efficiency. have.

Here, a cooling fluid passage 24 is formed between one gas passage 23 and the other gas passage 23 adjacent thereto, and flows in from the upper end of the gas channel part 20 and discharges to the lower end thereof. In the inner space of the cooling fluid passage 24, partition walls 22a and 22b are provided for switching the moving direction of the cooling fluid flowing from the cooling fluid inlet 42 to the cooling fluid outlet 43.

The partitions 22a and 22b are formed to partition the cooling fluid passage 24 through which the cooling fluid is moved in the inner space of the gas channel portion 20, and are formed vertically on the cooling fluid passage 24 so that the flow path is formed. As shown in FIG. 3, a pair of partitions 22a and 22b are provided at regular intervals so that the cooling fluid passage 24 of the gas channel part 20 is divided into three parts. have.

In this case, the number of partitions 22a and 22b and the number of partitions are preferably limited to the number and the number of partitions so as to realize the optimum heat transfer efficiency in the gas channel unit 20.

The barrier ribs 22a and 22b are formed to face each other toward the upper and lower ends of the gas channel part 20, and a predetermined portion extends from the upper and lower ends toward the center direction so that the cooling fluid passage 24 is provided. Cooling fluid for moving the zigzag can be moved.

As a result, an effect of extending the cooling fluid passage 24 through which the cooling fluid is moved can be obtained.

That is, in the case of the conventional EGR cooler, the linear housing in which the gas is moved is in contact with the cooling fluid flowing in one direction for a short time to exchange heat, but in the case of the EGR cooler for automobiles according to the present invention, a gas having a 'U' shape Since the housing in which the flow is made is in contact with the cooling fluid flowing in a zigzag shape for a sufficient time, the heat exchange is performed, thereby increasing the heat exchange efficiency between them.

7 is a perspective view showing the inner surface of the gas tube portion of the EGR cooler for automobiles according to the present invention.

The gas tube unit 30 is preferably configured to have a 'U' shaped rounding inner surface that is bent from the bottom to the upper side, through which the gas introduced from the lower side of the gas channel unit 20 is a gas tube unit ( After moving upward along the inner surface of 30, it may be discharged to the outside through the outlet 13a of the upper side of the inlet channel portion 10 via the gas channel portion 20.

In addition, the surface of the rounded inner surface of the gas tube part 30 is provided with a plurality of guide members 31 arranged at regular intervals in parallel in the exhaust gas traveling direction to increase heat transfer and smooth the flow of the exhaust gas. have.

The outer housing part 40 has the gas channel part 20 and the gas tube part 30 accommodated therein and mounted therein, and is fixed through the flanges 12, 21, and 41, and a cooling fluid inlet formed therein. The cooling fluid flows through the 42 and the cooling fluid outlet 43.

The cooling fluid inlet 42 is formed at the upper left of the outer housing part 40, and the cooling fluid outlet 43 is formed at the lower right of the outer housing part 40.

The positions of the cooling fluid inlet 42 and the outlet 43 can be changed in the up, down, front and rear directions, and can be in either a parallel flow or countercurrent heat exchanger.

In this case, the protrusion member 32 protruding to one side of the gas tube part 30 to the outside in order to improve the assemblability and the seismic resistance when the parts between the gas tube part 30 and the outer housing part 40 are coupled to each other. It is inserted into the groove 44 formed in the inner surface of the outer housing portion 40 so as to be firmly fixed.

As such, each of the components may include a first flange 12 formed at the right end of the inlet channel part 10 and a second flange 21 formed at the left end of the gas channel part 20 and the outer housing part 40. The third flange 41 formed at the left end of the) is fastened and fixed through a fastening means such as a rivet or a screw.

In this case, a gasket 50 is provided between the flanges 12, 21, and 41 to seal the gas and the cooling fluid from leaking.

Hereinafter, the flow of cooling water and exhaust gas will be described with reference to FIG. 2.

Cooling fluid (cooling water) flows into the cooling fluid passage 24 of the gas channel part 20 through the cooling fluid inlet 42 and exhausts the gas channel part 20 while changing the moving direction by the flow path between the partition walls. The gas is cooled and discharged from the EGR cooler through the cooling fluid outlet 43.

 Exhaust gas is used as the exhaust gas of the exhaust manifold of the engine, is introduced through the inlet (11a, 11b) and partly discharged through the outlet (13a), part of the gas inlet path ( 23a) is exchanged with the cooling fluid flowing into the cooling fluid passage 24 while passing through the gas passage 23, and then discharged to the outlet 13a and finally flows into the intake manifold.

Therefore, the present invention precisely casts through the aluminum die casting method so that the gas passage 23 and the cooling fluid passage 24 can be integrally formed in the gas channel portion 20, and the gas passage 23 and the cooling within the limited space. By extending the flow path of the fluid passage 24 to improve the heat exchange performance of the exhaust gas, it is possible to improve the weight of the product, the freedom of shape and appearance quality, and two inlets (11a, 11b) ), One inlet (11a) is a technology that is discharged through the outlet (13a) directly without passing through the EGR cooler to meet the warm-up (warm-up) conditions of the engine.

Although the above has been shown and described with respect to the preferred embodiments of the present invention, the present invention is not limited to the above-described embodiment, in the technical field to which the present invention pertains without departing from the spirit of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes will fall within the scope of the claims set forth.

Claims (12)

In the car EGR cooler, An inlet channel part 10 having two inlets 11a and 11b through which exhaust gas flows into a side surface, and a single outlet 13a on an upper side thereof; The gas channel part is formed in a hollow form, and a gas passage 23 through which gas can pass, and a cooling fluid passage 24 through which cooling water can pass between the gas passage 23 are integrally formed with each other ( 20); A gas tube part 30 having a rounded inner surface of a 'U' shape that is bent from bottom to top; The gas channel part 20 and the gas tube part 30 are accommodated and mounted therein, and include an outer housing part 40 having a cooling fluid inlet 42 and a cooling fluid outlet 43 formed therein. An EGR cooler for automobiles, which is configured to be precisely cast through an aluminum die casting process. The method of claim 1, Among the inlets 11a and 11b, an inlet 11b provided on one side of the inlets 11a and 11b is recirculated through the gas channel unit 20 and the gas tube unit 30 to discharge a recirculation route discharged to the outside through the outlet port 13a. And an inlet (11a) provided on the other side is provided with a route directly discharged through the outlet (13a). The method of claim 1, The gas passage (23) is a vehicle EGR cooler, characterized in that a plurality of fins (23c) to increase the contact area of the exhaust gas therein. The method according to claim 1 or 3, The gas passage 23 is partitioned horizontally on one side of the gas channel portion 20 is arranged in a plurality at regular intervals, and at the same time is formed in a slot-hole shape in the longitudinal direction EGR cooler. The method of claim 4, wherein The gas passage (23) is a vehicle EGR cooler, characterized in that the gas inlet passage (23a) of the lower side, and the gas discharge passage (23b) of the upper side. The method of claim 5, The gas passage (23) is the EGR cooler for automobiles, characterized in that the diameter of the center is the smallest, configured to increase toward both ends. The method of claim 1, The cooling fluid passage (24) is an EGR cooler for automobiles, characterized in that partitions (22a, 22b) for changing the direction of movement of the cooling fluid is installed in the inner space. The method of claim 7, wherein The partitions 22a and 22b are formed to vertically partition the cooling fluid passage 24 through which the cooling fluid is moved in the inner space of the gas channel part 20, and each of the partitions 22a and 22b is formed on the gas channel part 20. It is formed to face each other toward the lower end, EGR cooler for automobiles, characterized in that a predetermined portion extends toward the center direction from the upper and lower ends. The method of claim 1, The gas tube part 30 is an EGR cooler for automobiles, characterized in that a plurality of guide members 31 are arranged on the surface of the inner surface of the rounding at a predetermined interval in parallel in the exhaust gas traveling direction. The method according to claim 1 or 9, The gas tube part 30 has a protruding member 32 formed on one side thereof to improve the assemblability and the seismic resistance with the outer housing part 40, and the groove 44 on the inner side of the outer housing part 30. EGR cooler for cars characterized in that formed so as to be fixed to each other. The method of claim 1, Each of the first to third flanges 12, 21, and 41 formed at one side of the inlet channel part 10, the gas channel part 20, and the outer housing part 40 is provided through a fastening means. Automotive EGR cooler characterized in that the fastening is fixed. The method of claim 11, The first to third flanges (12, 21, 41) EGR cooler for cars, characterized in that provided with a gasket (50) for sealing the gas and cooling fluid to prevent leakage between.