KR102011754B1 - EGR cooler having improved durability - Google Patents

Abstract

According to the present invention, an exhaust gas recirculation (EGR) cooler comprises: a body cell having a hollow tube shape having both ends of a longitudinal direction open, and having a coolant inlet pipe and a coolant outlet pipe provided therein; a plurality of gas tubes arranged in a stacked structure in a thickness direction and introduced into the body cell; a cup plate on which one end of the plurality of gas tubes is inserted and fixed; a cover coupled to cover one end of the body cell and having a through hole formed in a center portion thereof; a stepped connector pipe having one side inserted into the through hole and the other side coupled to surround an edge of the cup plate, and capable of expanding and contracting in a longitudinal direction of the gas tube by bending a side wall stepwise in a direction in which an inner diameter thereof becomes narrower toward one side; an inlet flange coupled to the outside of the cover to guide inflow of gas to one side of the stepped connector pipe; and an outlet flange coupled to the other side of the longitudinal direction of the body cell to guide discharge of the gas passing through the gas tube.

Description

EZR Cooler having improved durability {EGR cooler having improved durability}

The present invention relates to an EZR cooler with improved durability, and more particularly, even if the gas tube expands during inflow of hot gas, it is possible to prevent the connection between the cup plate and the gas tube to be damaged, and to prevent noise and vibration caused by the gas inflow. It's about easy cooler that can be reduced.

In general, Exhaust Gas Recirculation (EGR) is a system in which a part of the exhaust gas is recycled back to the intake system to increase the concentration of CO 2 in the intake air, thereby lowering the temperature of the combustion chamber and thereby reducing the NOx.

On the other hand, the mechanism of NOx generation, in detail, 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 temperature (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 is reported to be the same level recently.

EZR is equipped with EZR cooler, which reduces NOx without increasing fuel economy and PM due to stricter diesel emission control, and installs a cooler (cooler) using coolant from the engine. 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 to be installed inside the car. Should be minimized, and condensation is generated from exhaust gas during heat exchange and sulfuric acid is included in the condensate because it is susceptible to corrosion. Since particulate matter (PM) of the exhaust gas can block the inside of the passage, countermeasure against fouling is required.

With reference to the accompanying drawings will be described in detail with respect to the conventional EZR cooler.

1 is a cross-sectional view of a conventional RG cooler.

In general, an EZR cooler includes a body cell 10 having an inner space, a plurality of gas tubes 20 installed in the body cell 10 through which exhaust gas flows, and ends of the gas tubes 20. A cup plate 30 for fixing to the body cell 10 and an inlet flange 40 for guiding gas inflow into the gas tube 20 are provided as basic components.

The space between the plurality of gas tubes 20 is secured to allow the cooling water to flow, and the body cell 10 and the gas tube 20 to allow the cooling water to flow between the body cell 10 and the gas tube 20. ) Is configured to maintain a distance apart.

In addition, the distance between the two neighboring gas tube 20, and the distance between the body cell 10 and the gas tube 20 can be kept constant, the width direction both sides of the gas tube 20 A plurality of baffles (not shown) are mounted in a zigzag pattern. Therefore, the coolant introduced into the body cell 10 flows along the periphery of the gas tube 20, exchanges heat with the exhaust gas in the gas tube 20, and is discharged to the outside of the body cell 10.

In this case, the gas introduced through the inlet flange 40 hits the front surface (left side in FIG. 1) of the cup plate 30 first and then flows into the gas tube 20, and the gas flows into the cup plate ( In the process of hitting 30), there is a disadvantage in that noise or vibration may occur greatly. In addition, in the conventional EZC cooler, since the cup plate 30 is fixedly coupled to the body cell 10, when the hot gas is introduced and the gas tube 20 is expanded in the longitudinal direction, the cup plate 30 and the gas Stress is concentrated in the connection between the tube 20 has a problem that cracks occur or break.

KR 10-0777105 B1

The present invention has been proposed to solve the above problems, it is possible to prevent the breakage of the connection between the cup plate and the gas tube when hot gas inlet, EZ R cooler that can reduce the vibration and noise generated during gas inlet The purpose is to provide.

Easy R cooler according to the present invention for achieving the above object, a hollow body having both ends in the longitudinal direction, the body cell provided with a cooling water inlet pipe and a cooling water outlet pipe; A plurality of gas tubes arranged in a stacked structure in a thickness direction and introduced into the body cells; A cup plate on which one end of the plurality of gas tubes is inserted and fixed; A cover coupled to cover one end of the body cell and having a through hole formed in a center portion thereof; One side is inserted into the through hole and the other side is coupled to surround the edge of the cup plate, and the side wall is bent stepwise in a direction that narrows the inner diameter toward one side stepped to expand and contract in the longitudinal direction of the gas tube Connector; Inlet flange coupled to the outside of the cover for guiding the inflow of gas to one side of the stepped connector; And an outlet flange coupled to cover the other side of the body cell in the longitudinal direction to discharge the gas passing through the gas tube.

The edge of the cup plate is spaced apart from the inner surface of the body cell.

The stepped connecting tube may include a first horizontal portion whose front end side is inserted into a through hole of the cover, a first vertical portion extending in a direction perpendicular to a rear end side of the first horizontal portion, and an end portion of the first vertical portion. A second horizontal portion extending rearward, a third vertical portion extending at right angles from a rear end side of the second horizontal portion, and a third extending rearward from an end of the third vertical portion to surround the cup plate with an edge; It is configured to include a horizontal portion.

The front end side of the first horizontal portion protrudes from one surface of the cover through a through hole of the cover, and the inlet flange is mounted to surround and fix a portion protruding from one surface of the cover.

The distance between the rear end of the first horizontal part and the front end of the second horizontal part and the distance between the rear end of the second horizontal part and the front end of the third horizontal part are each set to 1/10 or more of the overall height of the stepped connecting pipe. do.

The total length of the stepped connecting pipe is set to 1/12 or more of the total length of the EG cooler.

The stepped tube is made of a metal plate, it is manufactured to have a longitudinal recovery elasticity.

The EG cooler according to the present invention is configured such that the cup plate is movable when the gas tube is expanded in the longitudinal direction during the hot gas inflow process, thereby preventing the connection part between the cup plate and the gas tube from being damaged, and during gas inflow. The noise or vibration generated is significantly reduced, and the physical stresses generated during gas inflow are dispersed to improve durability of each component.

1 is a cross-sectional view of a conventional RG cooler.
Figure 2 is a perspective view of an EZ cooler with improved durability according to the present invention.
Figure 3 is an exploded perspective view of an EZ cooler with improved durability according to the present invention.
Figure 4 is a cross-sectional view of the EZR cooler with improved durability according to the present invention.
5 and 6 are a front view and a side cross-sectional view of the stepped connector included in the EZR cooler with improved durability according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the EZR cooler with improved durability according to the present invention.

Figure 2 is a perspective view of the easy-to-use EZR cooler with improved durability according to the present invention, Figure 3 is an exploded perspective view of the EZR cooler with improved durability according to the present invention, Figure 4 is a zigzag improved durability according to the present invention Sectional view of the cooler.

EZR cooler according to the present invention is a type of cooling device for cooling gas through heat exchange between cooling water and exhaust gas (hereinafter, abbreviated as 'gas'). The biggest feature is that it is not distributed.

That is, the EG cooler according to the present invention forms a hollow tube shape in which both ends in the longitudinal direction are opened, and is laminated in the thickness direction with the body cell 100 provided with the coolant inlet pipe 110 and the coolant outlet pipe 120. A plurality of gas tubes 200 which are arranged in a structure to be introduced into the body cell 100, a cup plate 300 to which one end of the plurality of gas tubes 200 is inserted and fixed, and the body cell ( Cover 400 is coupled to cover one end of the 100 and the through hole 410 is formed in the center portion, one side is inserted into the through hole 410 and the other side is coupled to surround the edge of the cup plate 300 And the side wall is bent stepwise in the direction that narrows the inner diameter toward one side and the stepped connecting pipe 500 and the expansion and contraction in the longitudinal direction of the gas tube 200 and coupled to the outside of the cover 400 Gas to one side of the stepped connector (500) The inlet flange 610 for guiding the mouth and the outlet of the gas coupled to cover the other longitudinal side of the body cell 100 and passed through the gas tube 200 is configured to include a guide flange 620. .

The coolant flows into the body cell 100 through the coolant inlet pipe 110, flows through the outer surface of the gas tube 200, and then is discharged through the coolant discharge pipe, and the gas flows through the inlet flange 610. After the heat exchange with the cooling water while flowing into and flowing into the tube 200, it is discharged to the outside through the outlet flange 620.

The gas tubes 200 are arranged in a structure in which a plurality of gas tubes 200 are stacked at regular intervals in a thickness direction (up and down direction in this embodiment) to be mounted in a plurality of body cells 100. The number of the gas tubes 200 mounted on the can be changed in various ways according to various conditions. When a plurality of gas tubes 200 are arranged in a stacked structure, a plurality of baffles 210 may be provided on both sides of the gas tube 200 so that a spaced distance between two neighboring gas tubes 200 is uniformly ensured. Is mounted. On the other hand, the shape and function of the body cell 100 and the gas tube 200 included in the present invention is applied to the conventional EZ cooler substantially the same bar, a detailed description thereof will be omitted.

At this time, the EG cooler according to the present invention, the cup plate 300 coupled to the front end (left end in Figure 4) of the plurality of gas tubes 200 is gas is directly fixed to the body cell 100 is coupled. Rather, the biggest feature of the configuration is that it is connected to the cover 400 through the stepped connector (500). The stepped connecting pipe 500 is manufactured to have a plurality of single layers along the inflow direction of the gas (in the direction of the arrow in FIG. 4), and is made of a metal plate having a predetermined range of ductility, that is, the inflow direction of the gas, It is provided with a function that can be extended to some extent along the longitudinal direction and restored.

As such, when the stepped connecting pipe 500 is manufactured to have a resilient elastic force in the longitudinal direction, hot gas is introduced into the gas tube 200 through the inlet flange 610 so that the gas tube 200 is in the longitudinal direction. When expanded to, the cup plate 300 coupled to the longitudinal end of the gas tube 200 is moved by the expansion distance of the gas tube 200, between the cup plate 300 and the gas tube 200 The connection part can be prevented from being broken. As such, when the cup plate 300 is moved in the expansion direction of the gas tube 200, the stepped connecting pipe 500 is compressed in the longitudinal direction, and when the gas tube 200 is cooled and contracted to its original state, the stairs The cup plate 300 is returned to its original position by the restoring force of the connection pipe 500.

As shown in FIG. 1, when the cup plate 30 having the plurality of gas tubes 20 coupled thereto is directly coupled to the body cell 10, the gas pressure is the front surface of the cup plate 20 (the left side in FIG. 1). When the stress is concentrated in the coupling portion between the cup plate 20 and the body cell 10 when applied to), the coupling portion between the cup plate 20 and the body cell 10 may be broken. In addition, when a large pressure is applied to the cup plate 30 fixedly coupled to the body cell 10, there is also a problem that vibration occurs in the cup plate 30, thereby causing noise.

The EZ cooler according to the present invention is another configuration in that the edge of the cup plate 300 is spaced apart from the inner surface of the body cell 100, as shown in Figure 4 to solve the above problems There are features of the award.

As such, when the edge of the cup plate 300 is spaced apart from the inner surface of the body cell 100, a large impact force is applied to the cup plate 300 in the process of gas inflow, so that the cup plate 300 is rearward (see In the embodiment, when pushed in the right direction), the stepped connecting pipe 500 absorbs the impact force applied to the cup plate 300 while expanding in the longitudinal direction, thereby generating vibration and noise generated in the gas inflow process. There is an advantage that can be significantly reduced.

 On the other hand, the gas introduced through the inlet flange 610 is introduced into the gas tube 200 passing through the interior of the stepped connecting pipe 500, the gas is introduced in a very high temperature state the stepped connecting pipe 500 It must be made of a material with a high melting point, such as silver metal. However, if the thickness of the stepped pipe 500 is not feared to be deformed or melted by the heat of the gas, but easily stretched or restored by the external force, that is, the longitudinal elastic recovery force is very low, noise and vibration reduction There is a problem in that it is difficult to obtain an effect or a component damage prevention effect due to stress concentration.

Therefore, it is preferable that the stepped pipe 500 is made of a metal plate having a predetermined thickness or less, and is formed to have high heat resistance and longitudinally resilient elasticity. For example, the stepped connecting pipe 500 may be manufactured by a process of pressing a metal plate having a thickness of 0.5 mm to 2.0 mm, and more preferably press working a metal plate having a thickness of 0.8 mm. It can be produced by the process. At this time, in the present embodiment, only the case of the stepped connector pipe 500 is a three-stage structure, the number of steps of the stepped connector pipe 500 may be applied in various ways, such as four or five stages.

FIG. 5 is a front view of a stepped connector 500 included in an EZC cooler having improved durability according to the present invention, and FIG. 6 is improved durability according to the present invention cut along line AA shown in FIG. 5. A side cross-sectional view of the cup plate 300 included in the EG cooler.

The stepped connecting pipe 500 is extended by the thermal expansion of the gas tube 200, the gas tube 200 is contracted to restore the original state to have a buffer function, that is to have a damping function at least It should be made to have three or more bends. That is, as shown in FIGS. 5 and 6, the stepped connector pipe 500 includes a first horizontal portion 510 inserted into a through hole 410 of the cover 400, and the first horizontal portion 510. A first vertical portion 520 extending in a direction perpendicular to the rear end side of the horizontal portion 510, a second horizontal portion 530 extending rearward from an end of the first vertical portion 520, and the second A third vertical portion extending perpendicularly from a rear end side of the horizontal portion 530 and a third horizontal portion 550 extending rearward from an end of the third vertical portion to surround the cup plate 300 with an edge; It can be configured to include.

The stepped connector 500 is the first horizontal portion 510 is coupled to the inlet flange 610, so that the coupling force of the stepped connector 500 and the inlet flange 610 can be ensured high, 1, the front end side of the horizontal part 510 penetrates the through hole 410 of the cover 400, protrudes from one surface of the cover 400, and the inlet flange 610 protrudes from one surface of the cover 400. It is preferred to be combined to surround the site. As such, when the inlet flange 610 is coupled to surround the protrusion of the first horizontal portion 510, the coupling area between the inlet flange 610 and the first horizontal portion 510 becomes very wide, so that the mutual coupling force is very high. You will get the effect. In this embodiment, only the case where the first horizontal portion 510 protrudes long enough to closely contact the entire inner circumferential surface of the inlet flange 610, but the protruding distance of the first horizontal portion 510 varies according to various design conditions. Can be changed.

When the stepped connector 500 is expanded and contracted in the longitudinal direction (left and right in FIG. 6), the first vertical portion 520 and the second vertical portion 540 are bent sideways, so that the first vertical portion It is preferable that the vertical length of the 520 and the second vertical portion 540 is sufficiently long. At this time, the vertical length of the first vertical portion 520 is a separation distance between the rear end of the first horizontal portion 510 (the right end in FIG. 6) and the front end of the second horizontal portion 530 (the left end in FIG. 6). Since the second vertical portion 540 is the separation distance between the rear end of the second horizontal portion 530 and the front end of the third horizontal portion 550, the rear end of the first horizontal portion 510 and the second horizontal portion The distance between the front end of the 530 and the rear end of the second horizontal part 530 and the front end of the third horizontal part 550 are set to 1/10 or more of the entire height of the stepped connecting pipe 500. This is preferred.

In addition, since the longitudinal extension rate increases as the overall length increases, the damping capacity for absorbing gas pressure increases, so that the overall length of the stepped connection pipe 500 is equal to the total length of the EG cooler. It is preferably set to 1/12 or more.

On the other hand, when the connection portion, that is, the corners are formed at right angles to the horizontal portion and the vertical portion, there is a fear that the stress is concentrated at the edge portion in the process of expanding and contracting the stepped connecting pipe 500, thereby being damaged. Therefore, the corner portion of the stepped pipe 500 is preferably rounded to have an R value. At this time, the greater the R value has the advantage of less damage to the corner portion, but if the R value is excessively large, the area of the side bent side of the first vertical portion 520 and the second vertical portion 540 is reduced The problem that the longitudinal expansion rate of the stepped connector 500 is reduced. Therefore, the corner portion of the stepped pipe 500 is preferably rounded to have an R value of 0.5 mm to 3.0 mm.

As mentioned above, although this invention was demonstrated in detail using the preferable Example, the scope of the present invention is not limited to a specific Example and should be interpreted by the attached Claim. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

100: body cell 110: cooling water inlet pipe
120: cooling water outflow pipe 200: gas tube
210: baffle 300: cup plate
400: cover 410: through hole
500: stepped connector 510: first horizontal portion
520: first vertical portion 530: second horizontal portion
540: second vertical portion 550: third horizontal portion
610: inlet flange 620: outlet flange

Claims (7)

A body cell having a hollow tube shape having both ends of the longitudinal direction open, and having a coolant inlet tube and a coolant outlet tube;
A plurality of gas tubes arranged in a stacked structure in a thickness direction and introduced into the body cells;
One end of the plurality of gas tube is inserted and fixed, the edge of the cup plate is spaced apart from the inner surface of the body cell;
A cover coupled to cover one end of the body cell and having a through hole formed in a center portion thereof;
One side is inserted into the through hole and the other side is coupled to surround the edge of the cup plate, and the side wall is bent stepwise in a direction that narrows the inner diameter toward one side stepped to expand and contract in the longitudinal direction of the gas tube Connector;
Inlet flange coupled to the outside of the cover for guiding the inflow of gas to one side of the stepped connector;
An outlet flange coupled to cover the other side of the body cell in the longitudinal direction to guide the discharge of the gas passing through the gas tube;
Including;
The stepped connecting pipe may include a first horizontal portion protruding from one surface of the cover through a through hole of the cover, a first vertical portion extending in a direction perpendicular to a rear end side of the first horizontal portion, A second horizontal portion extending rearward from an end of the first vertical portion, a third vertical portion extending perpendicularly from a rear end side of the second horizontal portion, and extending backward from an end of the third vertical portion to the cup plate; A third horizontal portion surrounding the edge,
The inlet flange is mounted to surround and secure the portion protruding from one surface of the cover,
The stepped connector tube is made of a metal plate, characterized in that it has a longitudinal resilient elastic force. delete delete delete The method according to claim 1,
The distance between the rear end of the first horizontal portion and the front end of the second horizontal portion, and the distance between the rear end of the second horizontal portion and the front end of the third horizontal portion are each 1/10 or more of the total height of the stepped connecting pipe. Easy cooler made with. The method according to claim 1,
The total length of the stepped connector is an ezr cooler, characterized in that more than 1/12 of the ezr cooler. delete

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