JP4477990B2 - EGR cooler water circuit connection method - Google Patents

Description

  The present invention relates to a water circuit connection method of an EGR cooler for cooling exhaust gas for recirculation.

  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 used between an appropriate position of the exhaust passage extending from the exhaust manifold to the exhaust pipe and an appropriate position of the intake passage extending from the intake pipe to the intake manifold. The exhaust gas is recirculated through an EGR pipe having an EGR valve connected thereto.

  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, so that the combustion temperature is effectively reduced without significantly reducing the output of the engine. Since the generation of NOx can be reduced, a water-cooled EGR cooler water circuit connection method is also provided in the middle of the EGR pipe for recirculating exhaust gas to the engine (for example, see Patent Document 1 below). reference).

  Here, as an example of the EGR cooler, as shown in FIGS. 7 and 8, the EGR cooler 1 includes a large number of tubes 2 that guide exhaust gas from a diesel engine, and a cylindrical shell that surrounds the large number of tubes 2. 3, an inlet 5 for guiding cooling water from the water supply pipe 4 to the outer periphery of the tube 2 is provided in the vicinity of one end of the shell 3, and in the vicinity of the other end of the shell 3. Is provided with an outlet 7 for guiding the cooled cooling water to the drain pipe 6. Then, the cooling water in the drain pipe 6 is guided to a water reservoir 8 where air is vented from the water reservoir 8 and the air that has been vented is recirculated from the water reservoir 8 into the engine or a radiator (not shown). To be sent to. In the figure, reference numeral 9 denotes an inlet bonnet serving as an exhaust gas inlet, and 10 denotes an outlet bonnet serving as an exhaust gas outlet.

In the EGR cooler 1 of FIG. 7, when the cooling water from the water supply pipe 4 is introduced into the shell 3 through the inlet 5, the cooling water exchanges heat with the exhaust gas introduced into the tube 2 from the diesel engine, and the exhaust gas is discharged. The cooling water after cooling and cooling the exhaust gas is discharged from the outlet 7 to the drain pipe 6.
JP 2003-184658 A

  On the other hand, in recent years, a configuration in which a plurality of EGR coolers are provided has been proposed. When a plurality of EGR coolers are provided in this way, for example, a configuration as shown in FIG. 9 is generally considered. That is, in FIG. 9, two cooler bodies 1A and 1B having the same configuration as the EGR cooler 1 of FIG. 7 are juxtaposed, and the water supply from the branch portion 16 is branched to each of the cooler bodies 1A and 1B. The water circuit is composed of a water supply pipe 4 to be supplied and a drain pipe 6 that guides the waste water to a water reservoir 8.

  However, in the configuration of FIG. 9, since the cooler main bodies 1A and 1B are each provided with the water supply pipe 4 and the drain pipe 6, there is a problem that the configuration of the water circuit becomes complicated. In such a narrow space, there is a problem in arrangement configuration.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an EGR cooler water circuit connection method capable of simplifying the configuration of a water circuit when a plurality of cooler bodies are provided.

  The present invention includes a tube that guides exhaust gas from a diesel engine, an inlet that surrounds the tube and guides cooling water from a water supply pipe to an outer periphery of the tube, and an outlet that guides cooling water after cooling to a drain pipe. A method for connecting a water circuit of an EGR cooler comprising a plurality of cooler bodies comprising a shell provided with a branch flow path for branching and supplying cooling water from the water supply pipe to the inlet of each cooler body A collecting channel that collects cooling water from the outlet of each cooler body and guides it to a drain pipe, wherein one of the branch channel and the collecting channel is a fixed pipe, and the other is a flexible hose. It relates to the water circuit connection method of the EGR cooler.

  In the EGR cooler water circuit connection method, it is preferable that the flexible pipes are connected in a substantially L shape.

  Further, in the water circuit connecting method of the EGR cooler, it is possible to connect using a substantially L-shaped pipe with a flange having a mounting hole having a diameter larger than that of the tightening bolt instead of the flexible pipe.

  According to the above means, the branch flow path for supplying the cooling water from the water supply pipe to the inlet of each cooler body, and the collective flow for collecting the cooling water from the outlet of each cooler body and leading to the drain pipe Since it connected with the path | route, the structure of a water circuit can be simplified. Furthermore, since one of the branch flow path and the collective flow path is a fixed pipe and the other is a flexible hose, it can be connected by absorbing a positional shift or the like when each cooler body is installed.

  Further, since the flexible pipes are connected so as to have a substantially L-shape, they can be easily connected even if there is a positional deviation between the inlets or the outlets when each cooler body is installed. Since the flexible tube is substantially L-shaped, it can be easily connected even in a narrow space.

  Further, instead of the flexible tube, by connecting using a substantially L-shaped pipe with a flange having a mounting hole larger in diameter than the tightening bolt, both the branch flow channel and the collective flow channel have rigidity strength. Can be connected with a pipe.

  According to the water circuit connection method for an EGR cooler of the present invention described above, the branch flow path for supplying the cooling water from the water supply pipe to the inlet of each cooler body, and the cooling water from the outlet of each cooler body Are connected by a collecting flow path that leads to the drain pipe, so that the configuration of the water circuit can be simplified, and therefore, there is an effect that it can be suitably applied to a narrow space around the engine, and further, a branch flow Since one of the path and the collective flow path is a fixed pipe and the other is a flexible hose, there is an effect that it is possible to easily absorb and connect misalignment when each cooler body is installed.

  Further, by connecting the flexible pipes having a substantially L shape, even if there is a positional deviation between the inlets or the outlets when installing each cooler body, the flexible pipes can be easily connected. Since the tube is substantially L-shaped, there is an effect that it can be easily connected even in a narrow space.

  Further, instead of the flexible tube, by connecting using a substantially L-shaped pipe with a flange having a mounting hole larger in diameter than the tightening bolt, both the branch flow channel and the collective flow channel have rigidity strength. There is an effect that can be connected with a pipe.

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

  1 to 3 show an example of an embodiment of the present invention. FIG. 1 is a plan view of a water circuit, FIG. 2 is a view taken in the direction of arrows II-II in FIG. 1, and FIG. It is a III direction arrow view, and attaches | subjects the same code | symbol to the same part as the structure shown to the said FIGS.

  In FIG. 1, as in FIG. 9, in the configuration provided with two cooler bodies 1 </ b> A and 1 </ b> B, the cooling water of the water supply pipe 4 is supplied to the inlet 5 b of the cooler body 1 </ b> B and via the branch channel 11. The cooler main body 1A is supplied to the inlet 5a. Further, the cooling water from the outlet 7 b of the cooler body 1 B is gathered together with the cooling water from the outlet 7 a of the cooler body 1 A by the collecting flow path 12 and led to the drain pipe 6. Although FIG. 1 shows a case where two cooler bodies 1A and 1B are provided, the present invention can also be applied to a case where three or more cooler bodies are provided.

  One of the branch channel 11 and the collecting channel 12 can be connected by a fixed pipe, and the other can be connected by a flexible tube such as a flexible hose or a flexible pipe. In the illustrated example, the branch channel 11 is connected by a flexible tube 13 as shown in FIGS. 1 and 2, and the collecting channel 12 is a straight fixed pipe having normal strength as shown in FIGS. 14 are connected. The branch channel 11 may be connected as a fixed pipe 14, and the collecting channel 12 may be connected as a flexible tube 13.

  The flexible tube 13 shown in FIG. 2 has a substantially L-shape, and both ends of the substantially L-shaped flexible tube 13 are connected to the inflow ports 5a and 5b by fastening nuts 15. Yes.

  Hereinafter, the operation of the embodiment of the present invention will be described.

  A part of the cooling water supplied from the water supply pipe 4 in FIGS. 1 and 2 is supplied to the cooler body 1B from the inlet 5b, and the rest is supplied to the cooler body 1A from the inlet 5a. The exhaust gas flowing in the tube 2 of 1B is cooled. On the other hand, the cooling water that has cooled the exhaust gas in the cooler body 1B flows out from the outlet 7b to the collecting channel 12, and the cooling water that cools the exhaust gas in the cooler body 1A and flows out from the outlet 7a. It joins and is led to the water reservoir 8 through the drain pipe 6.

  At this time, the cooling water from the water supply pipe 4 is branched and supplied to the inlets 5a and 5b of the respective cooler bodies 1A and 1B, and the cooling from the outlets 7a and 7b of the respective cooler bodies 1A and 1B. Since the collecting flow path 12 that collects water and guides it to the drain pipe 6 is connected, the configuration of the water circuit can be simplified. Further, as shown in FIG. 2, the branch flow path 11 is a flexible tube 13 and the collective flow path 12 is a fixed pipe 14 as shown in FIG. 3, so that the position shift at the time of installation of each cooler body 1A, 1B. Etc. can be absorbed and connected.

  That is, the cooler bodies 1 </ b> A and 1 </ b> B first connect the outlets 7 a and 7 b with the fixed pipe 14. At this time, the positions of the inlets 5a and 5b may deviate from errors such as manufacturing accuracy and assembly accuracy. However, since the inflow ports 5a and 5b are connected by a flexible tube 13 made of a flexible hose having a substantially L shape or a flexible pipe, they can be easily connected even if there is an error as described above. . That is, as shown in FIG. 4, when it is attempted to connect a narrow interval provided in a straight portion of the pipe with the flexible tube 13 ', it cannot be connected because it is difficult to bend due to the strength of the flexible tube 13' itself. In some cases, as described above, the flexible tube 13 formed in a substantially L shape increases the degree of freedom for connection, and can be easily connected even in a narrow space. On the other hand, since the cooler bodies 1A and 1B are connected by the fixed pipe 14 as described above, they can also maintain strength against vibration and the like.

  Further, in the branch flow path 11 having an L-shaped shape as described above, a substantially L-shaped pipe 17 having a configuration as shown in FIGS. 5 and 6 may be used in place of the flexible tube 13. it can. As shown in FIG. 5, the substantially L-shaped pipe 17 is provided with flanges 20 having attachment holes 19 having a diameter larger than that of the tightening bolts 18 at both ends. 21 is a seal ring.

  When the inflow ports 5 a and 5 b are connected using the substantially L-shaped pipe 17 shown in FIGS. 4 and 5 instead of the flexible tube 13, the mounting hole having a substantially L-shaped shape and a diameter larger than the tightening bolt 18. Since the mounting position of the substantially L-shaped pipe 17 can be adjusted in the direction of the arrow by the configuration with the flange 20 having 19, there are errors in the manufacturing accuracy and assembly accuracy of the positions of the inlets 5 a and 5 b. Even in a narrow space, it can be easily connected.

  Further, as described above, when the collective flow path 12 is connected by the fixed pipe 14 and then the branch flow path 11 is connected by the substantially L-shaped pipe 17, both are connected with rigidity strength. The assembly strength of 1A and 1B can be increased.

  In addition, the water circuit connection method of the EGR cooler of the present invention is not limited only to the above-described embodiment, and the circumferential position and the like of the inlet and outlet provided in the cooler body can be variously changed, Of course, various modifications can be made without departing from the scope of the present invention.

It is a top view of the water circuit which shows an example of the form 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 explanatory drawing at the time of connecting the narrow space | interval provided in the linear part of piping with a flexible tube. It is explanatory drawing which shows the state connected using a substantially L-shaped pipe. It is explanatory drawing of the flange with which a substantially L-shaped pipe is equipped. It is a schematic plan view which shows an example of an EGR cooler. It is an arrow directional view of the VIII-VIII direction of FIG. It is explanatory drawing in the case of providing multiple conventional EGR coolers.

Explanation of symbols

1A, 1B Cooler body 2 Tube 3 Shell 4 Water supply pipe 5a, 5b Inlet 6 Drainage pipe 7a, 7b Outlet 11 Branch flow path 12 Collecting flow path 13 Flexible pipe 14 Fixed pipe 17 Almost L-shaped pipe 18 Tightening bolt 19 Installation Hole 20 flange

Claims (3)

  A tube that guides exhaust gas from the diesel engine, a shell that surrounds the tube and that has an inlet that guides cooling water from the water supply pipe to the outer periphery of the tube, and an outlet that guides the cooled cooling water to the drain pipe A water circuit connecting method for an EGR cooler comprising a plurality of cooler bodies comprising: a branch passage for branching and supplying cooling water from the water supply pipe to the inlet of each cooler body; and each cooler body An EGR cooler characterized in that a collecting flow path for collecting cooling water from the outlet of the pipe and leading it to a drain pipe is provided, one of the branch flow path and the collecting flow path is a fixed pipe, and the other is a flexible pipe. Water circuit connection method.   The water circuit connecting method for an EGR cooler according to claim 1, wherein the flexible pipes are connected to each other having a substantially L shape.   The water circuit connecting method for an EGR cooler according to claim 1 or 2, wherein the flexible pipe is connected using a substantially L-shaped pipe with a flange having a mounting hole having a diameter larger than that of the tightening bolt. .

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