JP2006083709A - Bleeding structure of cooling water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bleeding structure of cooling water, decreasing the number of parts, and simplifying the structure to improve productivity. <P>SOLUTION: This air bleeding structure of cooling water includes: a cooling water feed line 12 connected to a cooling water outlet 21 of an EGR cooler body 11 to guide the cooling water whose temperature is elevated in an EGR cooler 2 to the feeding destination; an EGR side bleeding line 13 for bleeding the cooling water whose temperature is elevated in the EGR cooler 2; and an engine side bleeding line 14 for bleeding the cooling water whose temperature is elevated in an engine. The cooling water feed line 12, the EGR side bleeding line 13 and the engine side bleeding line 14 are integrated with the EGR cooler body 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an air vent structure for cooling water that draws air from an EGR cooler and cooling water from an engine.

  Conventionally, in an engine of a large vehicle such as a large truck, a part of exhaust gas is extracted from the exhaust side and returned to the intake side, and the exhaust gas returned to the intake side suppresses combustion of fuel in the engine. So-called exhaust gas recirculation (EGR) is performed in which the generation of NOx (nitrogen oxide) is reduced by lowering the combustion temperature.

  In general, when this type of exhaust gas recirculation is performed, an EGR pipe is provided between an appropriate position of the exhaust passage from the exhaust manifold to the exhaust pipe and an appropriate position of the intake passage from the intake pipe to the intake manifold. Connected to recirculate exhaust gas through EGR piping.

In addition, if the exhaust gas recirculated to the engine is cooled in the middle of the EGR pipe, the temperature of the exhaust gas is reduced and the volume of the exhaust gas is reduced, thereby effectively reducing the combustion temperature without significantly reducing the output of the engine. Since the generation of NOx can be reduced, a water-cooled EGR cooler is also provided in the middle of the EGR pipe for recirculating exhaust gas to the engine (see, for example, Patent Document 1 and Patent Document 2 below) ).
JP 2003-184658 A Japanese Patent Laid-Open No. 2001-3816

  Further, some of such EGR coolers are provided with a structure for extracting air from the cooling water so as to prevent local heating from being generated by the air remaining in the cooling water.

  FIG. 4 shows an example of a conventional cooling water bleed structure. In the figure, reference numeral 1 denotes an engine, 2 denotes an EGR cooler mounted on the upper side of the engine 1, and the EGR cooler 2 has just been introduced into the engine 1. A part of the cooling water 3 having a relatively low temperature is guided by the cooling water introduction pipe 4 and used for cooling, and the cooling water 3 heated by the heat exchange with the exhaust gas in the EGR cooler 2 is used as the cooling water supply pipe. 5 through the engine 1 to a radiator or the like (not shown).

  Further, the EGR cooler 2 is provided with an EGR-side air vent pipe 6 so that air can be vented from the heated coolant, and the engine-side air can be vented from the engine-cooled coolant similarly. A vent pipe 7 is provided, and the EGR side air vent pipe 6 and the engine side air vent pipe 7 are gathered into a collecting portion 9 via a joint 8 so that air is appropriately vented from the collecting portion 9 by the collecting pipe 10. It has become. Moreover, the air-cooled cooling water is supplied from the collecting pipe 10 to a header tank (not shown) or a radiator (not shown).

  However, if the EGR side air vent pipe 6 and the engine side air vent pipe 7 are provided independently and combined by the collecting portion 9 or the like, the number of parts increases and the structure becomes complicated, so that productivity can be improved. There was no problem. Further, since the reliability with respect to leakage of cooling water decreases with the increase in the number of parts and the complexity of the structure, it has been demanded to improve the reliability.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an air vent structure for cooling water that reduces the number of parts and simplifies the structure to improve productivity.

The present invention provides a cooling water supply line connected to the cooling water outlet of the EGR cooler main body so as to guide the cooling water heated by the EGR cooler to the supply destination, and EGR for extracting air from the cooling water heated by the EGR cooler. A cooling water bleed structure comprising a side air bleed line and an engine side air bleed line that draws air from the coolant heated by the engine,
The present invention relates to an air vent structure for cooling water, wherein the cooling water supply line, the EGR side air vent line, and the engine side air vent line are integrated with the EGR cooler body.

  According to the present invention, a part of the engine side air vent line is arranged at a position adjacent to the cooling water outlet, and the EGR side air vent line is configured to communicate from the coolant outlet to the adjacent position of the engine side air vent line. Is preferred.

  In the present invention, it is preferable that a part of the engine-side air vent line adjacent to the coolant outlet and an EGR-side air vent line are formed in the outlet portion that forms the coolant outlet.

  In the present invention, it is preferable that the cooling water supply line is arranged along the longitudinal direction of the EGR cooler body, and the engine-side air vent line is arranged substantially parallel to the cooling water supply line.

  As described above, the cooling water supply line, the EGR side air vent line, and the engine side air vent line are integrated into the EGR cooler body, so that the number of parts is reduced and the structure is simplified to improve the productivity. Can do. Moreover, since the number of parts can be reduced and the structure can be simplified, the reliability against leakage of cooling water can be improved.

  When a part of the engine side air vent line is arranged adjacent to the cooling water outlet and the EGR side air vent line is connected from the cooling water outlet to the adjacent position of the engine side air vent line, the EGR side air vent is formed. Since the line is simply configured at a short distance, the number of parts can be reduced, the structure can be simplified, and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  If you configure a part of the engine side air bleeding line adjacent to the cooling water outlet and the EGR side air bleeding line at the outlet part that forms the cooling water outlet, the EGR side air bleeding line can be configured very easily. The number of points can be reduced, the structure can be simplified, and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  When the cooling water supply line is arranged along the longitudinal direction of the EGR cooler main body and the engine side air vent line is arranged substantially parallel to the cooling water supply line, the cooling water supply line and the engine side air vent line are arranged. Since it is configured simply, the entire structure can be simplified and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  According to the cooling water air vent structure of the present invention described above, it is possible to achieve an excellent effect that the number of parts can be reduced and the structure can be simplified to improve productivity.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 to 3 show an embodiment for carrying out the present invention.

  The cooling water air venting structure of the present invention is a cooling water supply system that guides the cooling water heated by the EGR cooler 2 to the EGR cooler body 11 that can exchange heat between the exhaust gas of the engine 1 and the cooling water. A line 12, an EGR side air vent line 13 for extracting air from the cooling water heated by the EGR cooler 2, and an engine side air vent line 14 for extracting air from the cooling water heated by the engine 1 are integrated. ing.

  Specifically, the EGR cooler body 11 has a cooling water inlet 16 for introducing cooling water into the shell 15 on one side of a cylindrical shell 15 in which a heat exchange tube (not shown) is arranged. A first outer peripheral body 17 is formed, and a second outer peripheral body 19 having a cooling water connection port 18 for discharging cooling water from the inside of the shell 15 is formed on the other side. 17 is formed with a convex support portion 20 projecting outward, and the second outer peripheral body 19 is formed with a convex outlet portion 22 projecting outward and extending the cooling water outlet 21. ing. Here, on both sides of the shell 15, a bowl-shaped inflow bonnet 23 that allows the exhaust gas of the engine 1 to flow into the tube and a bowl-shaped discharge-side bonnet 24 that discharges the exhaust gas from the tube may be integrated. It may be attached later. Further, the cooling water inlet pipe 25 or its connecting portion may be integrated with the cooling water inlet 16 of the first outer peripheral body 17 or may be attached later.

  The cooling water supply line 12 is a cooling water supply pipe 26 that is connected to the cooling water outlet 21 of the outlet portion 22 and supported by the support portion 20 of the first outer peripheral body 17, and is an EGR cooler main body as a whole. 11 are arranged along the longitudinal direction.

  The engine-side air vent line 14 is supported by the support portion 20 of the first outer peripheral body 17 and is arranged to be substantially parallel to the cooling water supply pipe 26 of the cooling water supply line 12 and the second outer peripheral body. 19 is provided with an engine-side air vent line 27 connected to the outlet part 22 of the engine. The outlet part 22 is connected to the engine-side air vent line 14 at a position adjacent to the cooling water outlet 21 so as to communicate with the engine-side air vent line 27. Forming part. Here, a part of the engine side air vent line 14 of the outlet portion 22 extends in the coaxial direction from the engine side air vent pipe 27 and bends to the anti-cooling water supply line side at a midway position and penetrates to the side. is doing. Further, the discharge pipe 30 of the discharge line 29 or its connecting portion may be integrated with the through-hole 28 of the outlet portion 22 or may be attached later.

The EGR side air vent line 13 communicates at the outlet portion 22 from the vicinity of the cooling water outlet 21 to a part (adjacent position) of the engine side air vent line 14. Here, the diameter of the EGR side air vent line 13 is configured such that the cooling water pressure P1 of the EGR side air vent line 13 is substantially the same as the cooling water pressure P2 of the engine side air vent line 14, Further, the pressure P1 of the EGR side air vent line 13 becomes higher than the pressure P3 of the discharge line 29 due to the diameter of the cooling water feed line 12, the engine side air vent line 14, the discharge line 29, and the like. The pressure is lower than the pressure P4 in the line 12. Moreover, these relationships are expressed by the following equations.
[Equation 1]
P4> P1 (≈P2)> P3

  The operation of the embodiment of the present invention will be described below.

  When the cooling water is vented by the EGR side air vent line 13 and the engine side air vent line 14, the cooling water heated up by heat exchange and discharged from the shell 15 of the EGR main body is cooled by the outlet 22. From the vicinity of the water outlet 21, the EGR side air vent line 13 and part of the engine side air vent line 14 are sent to the discharge line 29. Then, the air is discharged from the engine side air vent line 14 to the discharge line 29, and the air is appropriately vented from the cooling water, and is supplied to a header tank (not shown) or a radiator (not shown).

  Here, since the pressure P1 of the EGR side air vent line 13 is substantially the same as the pressure P2 of the engine side air vent line 14 and is higher than the pressure P3 of the discharge line 29, the EGR side air vent line 13 and the engine side Cooling water can be supplied to the discharge line 29 from the air vent line 14. In addition, when the pressure P1 of the EGR side air vent line 13 and the pressure P2 of the engine side air vent line 14 are not substantially the same, there is a problem that the cooling water flows backward to a low pressure line.

  Thus, according to the embodiment, the cooling water supply line 12, the EGR side air vent line 13, and the engine side air vent line 14 are integrated with the EGR cooler body 11, so that the number of parts is reduced. At the same time, the structure can be simplified to improve productivity. Moreover, since the number of parts can be reduced and the structure can be simplified, the reliability against leakage of cooling water can be improved.

  A part of the engine side air vent line 14 is arranged at an adjacent position in the vicinity of the cooling water outlet 21, and the EGR side air vent line 13 is connected from the cooling water outlet 21 to an adjacent position of the engine side air vent line 14. Then, since the EGR side air vent line 13 is simply configured with a short distance, the number of parts can be reduced, the structure can be simplified, and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  When a part of the engine side air vent line 14 adjacent to the coolant outlet 21 and the EGR side air vent line 13 are formed in the outlet portion 22 that forms the coolant outlet 21, the engine side air vent line is formed in the outlet portion 22. Since the EGR side air vent line 13 is provided with a part of 14 and is very simply configured, the number of parts can be reduced, the structure can be simplified, and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  When the cooling water supply line 12 is arranged along the longitudinal direction of the EGR cooler main body 11 and the engine-side air bleeding line 14 is arranged substantially parallel to the cooling water supply line 12, the cooling water supply line 12 and the engine Since the side air vent line 14 is simply configured, the entire structure can be simplified and the productivity can be further improved. Further, the reliability against leakage of cooling water can be further improved.

  In addition, the air bleeding structure of the cooling water of the present invention is not limited only to the above-described embodiment, but the EGR cooler body, the cooling water supply line, the EGR side air bleeding line, the engine side air bleeding line, and the outlet portion. Of course, the shape may be changed, and various changes may be made without departing from the scope of the present invention.

It is a top view which shows the example of an embodiment which implements this invention. It is an arrow view of the II-II direction of FIG. It is an arrow view of the III-III direction of FIG. It is a conceptual diagram which shows the conventional air bleeding structure of cooling water.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 EGR cooler 11 EGR cooler main body 12 Cooling water supply line 13 EGR side air vent line 14 Engine side air vent line 21 Cooling water outlet 22 Outlet part

Claims (4)

A cooling water supply line connected to the cooling water outlet of the EGR cooler main body so as to guide the cooling water heated by the EGR cooler to the supply destination, and an EGR side air bleeding line for extracting air from the cooling water heated by the EGR cooler And an air vent structure for cooling water with an air vent line on the engine side for extracting air from the cooling water heated by the engine,
An air vent structure for cooling water, wherein the cooling water supply line, the EGR side air vent line, and the engine side air vent line are integrated with the EGR cooler body.   A part of the engine side air vent line is arranged adjacent to the cooling water outlet, and the EGR side air vent line is configured to communicate from the coolant outlet to the adjacent position of the engine side air vent line. The air vent structure for cooling water according to claim 1.   The cooling water according to claim 1 or 2, wherein a part of the engine-side air vent line adjacent to the coolant outlet and an EGR-side air vent line are formed in the outlet portion forming the coolant outlet. Air vent structure.   The cooling water supply line is disposed along the longitudinal direction of the EGR cooler body, and the engine-side air vent line is disposed substantially parallel to the cooling water supply line. The cooling water air vent structure described in 1.

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