KR100814071B1 - Egr cooler - Google Patents

Abstract

An EGR cooler is provided to reduce fouling and manufacturing cost by embedding a wave pin in an exhaust gas tube. An EGR cooler(15) comprises a body cell(20), cooling water inlet and outlet(70,71), a plurality of exhaust gas tubes(80), a cover plate(40), a wave pin(90), a left flat plate(30) having a plurality of slot type through holes(31), a first right flat plate(50) having a through hole(51) and a plurality of combining holes(52) at an edge, and a second right flat plate(60) having a plurality of slot type through holes(61) and a plurality of combining holes(62) at an edge. The plural exhaust gas tubes are embedded in the body cell, and have a slot type section. The cover plate is located at left side of the body cell to seal left ends of the exhaust gas tubes and contacted with the exhaust gas tubes respectively. The wave pin formed in a wave shape is inserted to the exhaust gas tube and extended from a right end of the body cell, which divides an exhaust gas path vertically.

Description

EZR Cooler {EGR cooler}

1 is a schematic diagram showing the principle of an Exhaust Gas Reciculation (EGR) device.

2A is a perspective view of an EG cooler conventionally used.

FIG. 2B is a cross-sectional view of the A-A direction in FIG. 2A.

3 is a perspective view of an EG cooler according to the present invention.

4 is an exploded perspective view of an EG cooler according to the present invention.

5A and 5B are front and right side views of the EZC cooler according to the present invention.

6A and 6B are perspective views each showing a wave fin according to the present invention.

7 is a perspective view showing an exhaust gas tube having a wave fin embedded therein according to the present invention.

* Brief Description of Drawings *

15 ... EZR Cooler

20 ... body 21 ... left 22 ... right

23 ... Horizontal bulkhead 24 ... Upper space 25 ... Lower space

30 ... Left flat plate 31 ... Slot through hole

40.Cover plate 41 ... Bottom 42 ... Side

50 Right first flat plate 51 ... Through hole 52 ... Tightening hole

60 ... Right second flat plate 61 ... Slot through hole 62 ... Tightening hole

70 ... cooling water inlet 71 ... cooling water outlet

80 Exhaust gas tube 81 Left 82 Right

83 ... space

90 ... wave pin 91 ... type 92 ... channel

93 ... plate 94 ...

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in an automobile exhaust gas recirculation device (EGR) for supplying exhaust gas from an exhaust manifold to an intake manifold, and relates to an EG cooler for cooling and supplying the exhaust gas by cooling water.

In general, the EZR unit recycles a part of the exhaust gas back to the intake system, so that CO _{2 in} the intake air is It is a technique of increasing the concentration to lower the temperature of the combustion chamber and thereby reducing the NOx.

Specifically, we first look at the mechanism of NOx generation. Air consists of about 79% nitrogen, 21% oxygen and other trace elements. At room temperature, nitrogen and oxygen do not react with each other, but at high temperatures (above about 1450 ° C) they react with each other to form nitrogen oxides (thermal NOx). In particular, diesel engines generate combustion by compression ignition method, and the compression ratio is getting higher due to the development of the material of the cylinder, thereby increasing the temperature of the combustion chamber. Increasing the combustion chamber temperature increases the efficiency of the thermodynamic engine, but a large amount of nitrogen oxides are generated due to the high temperature. These nitrogen oxides are the main harmful substances that destroy the global environment, causing acid rain, optical smog, respiratory disorders, and the like.

The principle of NOx reduction by EZR is to lower the maximum temperature of the combustion chamber by recirculating inert gas (steam, carbon dioxide, etc.), and second, to prevent the atmosphere of nitrogen oxides produced by lean combustion, and To reduce the ignition delay and lower the local maximum temperature and pressure in the combustion chamber.

On the other hand, in the diesel engine, unlike the gasoline, the NOx reduction mechanism by EGR has been reported that the reduction of the oxygen concentration is the root cause and the study that the flame temperature decrease is the cause. At this time, no conclusion about which is right is given, but the contribution of NOx reduction in oxygen concentration and flame temperature has recently been reported to be at the same level.

EZR Cooler equipped with EZCooler is a method that reduces NOx without increasing fuel economy and PM due to stricter exhaust emission control of diesel engines. It is a device that can be obtained.

In this case, the EZR cooler should be cooled to 700 ℃ to 200 ℃, so it must be heat-resistant, and must be compactly designed for installation inside the car. Should be minimized, and condensation is generated from exhaust gas during heat exchange, and sulfuric acid in fuel is susceptible to corrosion because sulfuric acid is included in condensate, and it must be corrosion-resistant material, and mechanical load acts due to pulsation effect of exhaust gas. Since particulate matter (PM) of the exhaust gas can block the inside of the pipe, countermeasures against fouling are required.

In the related art, as shown in FIG. 1, the exhaust gas recirculation apparatus 1 recycles a part of the exhaust gas exhausted through the exhaust manifold 3 to the intake manifold 2 to reduce the generation of NOx. It is.

As shown in Fig. 1, a shell & tube type cooler 4 is installed in the exhaust gas recirculation path so that the exhaust gas can be supplied in a cooled state. The coolant of the engine 10 is used as the cell fluid, and the coolant flows in from the coolant inlet 7in and flows out to the coolant outlet 7out. Exhaust gas is used as the tube fluid, and the exhaust gas flows through the right conduit 6in extending from the exhaust manifold 3 and flows out to the left conduit 6out extending to the intake manifold 2. Reference numeral 11 in the drawings shows a combustion chamber.

The conventional easy cooler 4 used in Figs. 2A and 2B is shown. The EG cooler shown in FIG. 1 is a double tube type and the EG cooler shown in FIGS. 2A and 2B is a cell 1 pass and tube 2 pass type heat exchanger. The former and latter EZR coolers share the same reference numbers because they are roughly the same. However, the cover portion on the right side where the inlet and outlet of the exhaust gas is installed is not shown.

Cooling water flows in through the inlet 7in and flows out through the outlet 7out. Exhaust gas is introduced through the exhaust gas inlet (not shown), and the exhaust gas flowing out through the partition 12 extending into the cover (not shown) and the outgoing exhaust gas are distinguished, and the incoming exhaust gas is the exhaust gas. Passing through the tube (5in), the U-Flow Cap (13, U-Flow Cap) is turned up and down to pass through the exhaust gas tube (5out), and is discharged through the exhaust gas outlet (not shown). The discharged exhaust gas flows into the right conduit 6out connected to the intake manifold 2 of FIG.

By the way, the U-flow cap of the conventional EZC cooler is made of steel and manufactured by a process such as deep drawing (a kind of plastic processing for relatively deep processing of a product's depth), and the deep drawing molding is a multi-stage press. There is a problem that the manufacturing cost is increased to go through six to seven steps. In addition, since the coolant does not flow inside the yuflow cap, an unnecessary portion is generated in which the exhaust gas is not cooled, and there is a problem of occupying only an internal installation space of the vehicle.

The present invention has been made to solve the above problems and the like, the object of the present invention is to remove blind spots in which the exhaust gas is not cooled in the easy cooler.

It is also an object of the present invention to provide an easy-to-use cooler which improves the performance of the cooler, has a compact size, simplifies parts, is inexpensive to manufacture and reduces fouling.

The present invention is used in an automobile exhaust gas recirculation device (EGR: Exhaust Gas Reciculation) for supplying the exhaust gas from the exhaust manifold to the intake manifold, the exhaust gas is cooled and supplied by the cooling water, the exhaust gas inlet, outlet An EZ cooler comprising an installed cover and a partition for partitioning an inner space of the cover, comprising: a body cell; A cooling water inlet and an outlet formed in the body cell; A plurality of exhaust gas tubes embedded in the body cell and having a slotted cross section; A cover plate positioned on the left side of the body cell and in contact with each of the exhaust gas tubes to seal the left end of each of the exhaust gas tubes; The exhaust gas passage is partitioned in the vertical direction in order to extend in the left and right longitudinal directions so that the exhaust gas is inserted into the exhaust gas tube and has a wave shape, and starts at the right end of the body cell and extends from the left end to the right side of the exhaust gas. Wave pins spaced apart from each other; Include.

In addition, in a specific method of sealing the left end and the right end of the body cell and a specific fastening structure with a cover provided with an exhaust gas inlet and an outlet, the left flat plate is a flat plate to seal the left end of the body cell in the present invention. Each of the exhaust gas tubes has a plurality of slotted through holes inserted therebetween, and is located between the cover plate and the left end of the body cell; The right first flat plate is a flat plate and has one through hole into which the entire exhaust gas tube is inserted, and a plurality of fastening holes are provided at an outer side thereof and are assembled while wrapping the outside of the right end of the body cell; In order to seal the right end of the body cell, the right second flat plate is a flat plate and has a plurality of slot-type through holes into which each of the exhaust gas tubes is inserted. It is located on the right side of.

On the other hand, in order to simplify the parts of the cover plate and the like, the bottom portion of the cover plate is in contact with the left side of the left flat plate.

The body cell, the cooling water inlet, the cooling water outlet, the exhaust gas tube, the wave fin, the cover plate, the left flat plate, and the right first and second plates are made of SUS material.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

3 and 4 show a perspective view and an exploded perspective view of the EG cooler 15 according to the present invention. Preferably, the EZC cooler 15 is a cell 1 pass and tube 2 pass type heat exchanger.

The EG cooler 15 is composed of a body cell 20, a coolant inlet and an outlet 70, 71, a cover plate 40, an exhaust gas tube 80, and a wave fin 90.

A right cover (not shown) is assembled on the right side of the body cell 20, and a horizontal bulkhead 23 is installed inside the right cover so as to partition up and down inside thereof, and an exhaust gas inlet (not shown) is installed in the upper space. And an exhaust gas outlet (not shown) is installed in the lower space.

The body cell 20 is preferably a rectangular parallelepiped, rectangular pipe or rectangular duct, and the left end 21 and the right end 22 are open.

The cooling water inlets and outlets 70 and 71 are preferably spaced diagonally above the body cell 20. Either cocurrent or countercurrent heat exchangers are possible.

The cooling water inlets and outlets 70 and 71 are preferably made of SUS material, and beads 72 and beads are formed at upper and lower portions thereof, and lower ends thereof are brazed and fixed to the body cell 20. Such brazing is a kind of welding in which the base metal is not damaged by adding a filler material below the melting point of the wool material to be joined at 450 ° C. or higher.

The cover plate 40 is preferably in the form of a rectangular lid and is wrapped around the outer end of the left end 21 of the body cell and fixed by brazing to seal the left end 21 of the body cell.

The cover plate 40 is preferably made of SUS material and consists of a bottom portion 41 and a side surface 42, and has a low depth from an upper opening portion to a bottom portion 41, so that the exhaust gas is discharged from the body cell ( 20) and flows out U-turn in a manner described later without departing from. As a result, the cover plate 40 can be easily manufactured, and a blind spot where the occupied space is small and the exhaust gas is not cooled during installation is removed.

The exhaust gas tube 80 preferably has a slot-shaped cross section, and is preferably made of a single piece of SUS material or the like, and the left and right ends (Figs. 7, 81 and 82) are open.

As shown in FIGS. 5A and 5B, the exhaust gas tube 80 begins at the right end of the body cell (FIGS. 4 and 22) and extends beyond the left end of the body cell (FIGS. 5A and 21) and the exhaust gas tube. The left end 81 of is in contact with the right side of the bottom portion 41 of the cover plate, so that the left end 81 of the exhaust gas tube is sealed. As a specific sealing method, assembly of a method of applying a compressive force to the exhaust gas tube 80 may be used, and an adhesive applied to the left end 81 of the exhaust gas tube may be used.

The exhaust gas tube 80 is a number of, for example, five is inserted into the interior of the body cell 20, the slot-shaped cross-section upper part is an exhaust gas inlet (or inlet passage) by the method described later and the slot The lower part of the die cross section becomes an exhaust gas outlet (or outlet passage). The exhaust gas tube 80 and the wave fins 90, which will be described later, reduce the number of single components constituting the EZC cooler, simplify the assembly process, and reduce the cost and manufacturing cost of the product. In addition, due to the simplification of the shape, the workability is improved and the quality is improved. In addition, turbulence is easily formed, and countermeasure against fouling due to PM is easy.

The wave fin 90 is a plate on which a waveform 91 is formed, as shown in FIGS. 6A and 6B. A round type wave fin with rounded waveform 91 is shown in FIG. 6A and a square type wave fin with waveform 91 squared is shown in FIG. 6B. The period or pitch of the waveform is preferably 4.0 mm to 6.0 mm, and recesses or convex portions 94 are formed in the diaphragm 93 of the wave fins to enlarge the heat transfer area of the exhaust gas and to improve turbulence. Easily formed. Each valley of the wave fin 90 is used as a channel 92 through which exhaust gas flows by a method described below.

The wave fin 90 is embedded in the exhaust tube 80 as shown in FIGS. 5A, 5B, and 7. In the built-in direction, preferably each of the diaphragm 93 is divided into the vertical space of the exhaust gas tube (80). As a result, a plurality of channels 92 formed by the diaphragm 93 and the exhaust gas tube 80 are formed in the longitudinal direction. In the up-and-down sealing of the channel 92, the wave fin 90 and the exhaust gas tube 80 are preferably assembled in a force-fitting manner, or an adhesive or a sealing material is attached to the acid portion of the wave fin 90. Can be. Even if it is somewhat less sealed, it is not a big problem since only mixing between exhaust gases occurs.

The wave fin 90 extends starting from the right end 82 of the exhaust gas tube 80 and extending from the left end 81 of the exhaust gas tube 80 to the right side in the left and right longitudinal direction. Spaced apart spaces 83, which are spaced apart from each other, are formed inside the exhaust gas tube 80 as illustrated in FIGS. 5A and 7. The exhaust gas is u-turned in the separation space 83 and flows out.

The inflow and outflow of exhaust gas will now be described.

First, a right cover (not shown) is assembled on the right side of the body cell 20, and horizontal partitions (FIGS. 3, 5A and 23) are installed to partition the inside of the right cover up and down. The exhaust gas tube 80 is divided into upper and lower spaces 24 and 25 by the horizontal partition 23. The channel 92 of the wave fin located in the upper space 24 is preferably used as an inlet (or inlet passage) of the exhaust gas, and the channel 92 of the wave fin located in the lower space 25 is preferable. Preferably as an outlet (or outlet passage) of the exhaust gas.

In this way, the exhaust gas is introduced through the channel 92 of the wave fin located in the upper space 24, is cooled by the coolant inside the body cell 20, and the left end of the exhaust gas tube 80. U-turn up and down in the space 83, which is located nearby, flows into the channel 92 of the wave fin located in the lower space 25, is cooled by the coolant in the body cell 20, Outflow from the channel 92 of the wave fin located in the space, the exhaust gas finally flows into the intake manifold (not shown).

The preferred embodiment of the specific method of sealing the left end, the right end of the body cell 20 and the specific fastening structure with the cover in which the exhaust gas inlet and outlet are installed will be described.

As shown in FIGS. 4 and 5A, the EZR cooler 15 preferably includes a left flat plate 30 and a right first and second flat plates 50 and 60, and a left flat plate 30. The right and the second plate 60 fixedly supports and seals the exhaust gas tube 20, and separates the passage of the cell from the passage of the tube. The right first flat plate 50 serves as a flange for assembling with the right cover of the body cell in which the bypass valve and the like are mounted.

The right first flat plate 50 is a flat plate and has one large through hole 51 in the center thereof, so that the entire exhaust gas tube is inserted. In addition, a plurality of fastening holes 52 are provided at an outer side of the right first flat plate 50, and screwed with the right cover of the body cell.

The right first flat plate 50 is assembled to the body cell 20 while surrounding the right end 22 of the body cell, and the body cell 20 and the right first flat plate 50 are brazed. In addition, leakage of cooling water or leakage of exhaust gas is prevented.

The left flat plate 30 is a flat plate and has a plurality of slot-type through holes 31 so that each of the exhaust gas tubes 80 is inserted to fix the exhaust gas tubes 80. The part where the left flat plate 30 and the exhaust gas tube 80 contact each other is sealed by brazing, and the part where the left flat plate 30 and the body cell 20 contact each other is also sealed by brazing. Do not allow the coolant to mix with the exhaust gases.

The left flat plate 30 is preferably located between the left side of the left end 21 of the body cell and the cover plate 40 as shown in FIG. 5A.

The right second flat plate 60 is a flat plate and has a plurality of slot-type through holes 61 so that each of the exhaust gas tubes 80 is inserted to fix the exhaust gas tubes 80. The part where the right second flat plate 60 and the exhaust gas tube 80 contact each other is sealed by brazing, and the part where the right second flat plate 60 and the body cell 20 contact each other is brazing, etc. Sealed to prevent cooling water from mixing with the exhaust gases.

In addition, a plurality of fastening holes 62 are provided outside the right second flat plate 60 to screw the right first flat plate 60 and the right cover of the body cell.

The right second flat plate 60 is preferably located on the right side of the right end 22 and the right first flat plate 50 of the body cell, as shown in FIG. 5A.

In this way, the through hole 31 of the left flat plate and the through hole 61 of the right second flat plate are provided, and the left and right ends 81 and 82 of the exhaust gas tube 80 are inserted and supported. .

Hereinafter, the flow of the cooling water and the exhaust gas will be described.

The coolant is a cell fluid and the engine coolant is used and flows into the EG cooler 15 through the coolant inlet 70, cools the exhaust gas inside the body cell 20, and the EZR through the coolant outlet 71. It flows out of the cooler 15.

The exhaust gas is exhaust gas of the exhaust manifold of the engine, and flows in through the channel 92 of the wave fin located in the upper space 24 partitioned by the horizontal partition wall 23 in the right cover (not shown). The inside of the body cell 20 is cooled by a coolant, the upper and lower U-turn in the separation space 83 located at the left end of the exhaust gas tube 80 of the wave fin located in the lower space 25 Flows into the channels 92, is cooled by the coolant in the body cell 20, and flows out of the channel 92 of the wave fin located in the lower space, and the exhaust gas is finally intake manifold ( (Not shown).

The present invention has the effect of reducing the number of parts constituting the EG cooler, the assembly process is simplified, and the unit cost and manufacturing cost of the product by the exhaust tube and the wave fin having a built-in spaced space. In addition, due to the simplification of the shape, the workability is improved and the quality is improved. In addition, there is an effect that fouling (fouling) is reduced.

The present invention is a fastening structure between the cover plate and the body cell, the exhaust gas flows out u-turn without leaving the body of the body cell and facilitates the manufacture of the cover plate, less occupied space during installation, exhaust gas is cooled There is an effect that blind spots are not removed. Overall, the performance of the cooler is improved.

Claims (4)

delete Used for automobile exhaust gas recirculation (EGR) that supplies exhaust gas from the exhaust manifold to the intake manifold, the exhaust gas is cooled and supplied by cooling water, and a cover provided with an exhaust gas inlet and an outlet. It relates to an EG cooler comprising a partition for partitioning the inner space of the cover, Body cells; A cooling water inlet and an outlet formed in the body cell; A plurality of exhaust gas tubes embedded in the body cell and having a slotted cross section; A cover plate positioned on the left side of the body cell and in contact with each of the exhaust gas tubes to seal the left end of each of the exhaust gas tubes; The exhaust gas passage is partitioned in the vertical direction in order to extend in the left and right longitudinal directions so that the exhaust gas is inserted into the exhaust gas tube and has a wave shape, and starts at the right end of the body cell and extends from the left end to the right side of the exhaust gas. Wave pins spaced apart from each other; In the EG cooler to include, A left flat plate positioned between the cover plate and the left end of the body cell, the flat plate having a plurality of slotted through holes into which each of the exhaust gas tubes is inserted; A right first flat plate which is assembled while covering the outside of the right end of the body cell, is a flat plate, has one through hole into which the entire exhaust gas tube is inserted, and has a plurality of fastening holes at the outside thereof; And Located on the right side of the right first flat plate, a flat plate, having a plurality of slot-type through-holes each of the exhaust gas tube is inserted, the outer right second flat plate with a plurality of fastening holes; Easy cooler characterized in that. The easy cooler of claim 2, wherein a bottom portion of the cover plate is in contact with a left side of the left flat plate. The easy body according to claim 3, wherein the body cell, the cooling water inlet, the cooling water outlet, the exhaust gas tube, the wave fin, the cover plate, the left flat plate and the right first and second plates are made of SUS. Al cooler.

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