JP6582848B2 - Engine cooling system - Google Patents

Description

  The present invention relates to an engine cooling system that cools cooling water using two radiators.

In recent years, as a measure to comply with engine downsizing and exhaust gas regulations, an engine having a sub-radiator and an intercooler that cools cooling water to near atmospheric temperature to cool intake air that is compressed by a turbocharger and sucked into the engine A cooling system has been developed.
For example, Patent Document 1 below discloses a cooling system in which a part of cooling water cooled by a main radiator is further cooled by a sub radiator and then introduced into an intercooler to exchange heat with intake air flowing through the intercooler. Has been.

JP 2008-38891 A

  However, in the above cooling system, the cooling water is branched from the first cooling path provided with the main radiator as the first radiator to the second cooling path provided with the sub-radiator as the second radiator. The cooling water is returned from the cooling path to the first cooling path. In such a case, since the flow rate of the cooling water flowing through the second cooling path depends on the flow rate of the cooling water in the first cooling path, it is difficult to stabilize the flow rate of the cooling water flowing through the second cooling path. It was. As a result, it is difficult to control the temperature of the cooling water in the second cooling path.

  Therefore, the present invention has been made in view of these points, and an object thereof is to stabilize the flow rate of cooling water flowing through the second cooling path.

In the first aspect of the present invention, a first cooling path through which cooling water for the engine circulates, a first radiator provided in the first cooling path for cooling the cooling water that has passed through the engine, and the first A first pump that is provided in one cooling path and circulates the cooling water, and branches from the first cooling path at a branch point upstream of the first pump in the circulation direction of the first cooling path, and the circulation A second cooling path that merges with the first cooling path at a confluence on the upstream side of the first pump in a direction, and a part of the cooling water that is provided in the second cooling path and is cooled by the first radiator An engine cooling system comprising: a second radiator that further cools the second cooling path; and a second pump that is provided in the second cooling path and controls a flow rate of the cooling water in the second cooling path.
According to such an engine cooling system, since the cooling water is branched and merged at the branch point and the merge point on the upstream side of the first pump, the branch point and the merge point are provided on the upstream side and the downstream side of the first pump, respectively. Compared to the case, the influence on the flow of the cooling water by the rotation of the first pump can be suppressed. Further, since the second pump can perform intermittent operation, continuous operation, variable operation, and the like, for example, it becomes easy to adjust the flow rate of the cooling water in the second cooling path, so the flow rate of the cooling water in the second cooling path is stabilized. it can.

  Further, the first cooling path may be provided with a branching / merging portion branched so as to be orthogonal to four directions so that the branching point and the joining point are at the same position.

  Further, a partition wall along the axial direction is provided in the branch / merging portion in order to restrict the cooling water flowing through the second cooling path and reaching the merging point to the second radiator side. It is good to be.

  In addition, the branching / merging portion may be a double pipe in order to restrict the cooling water flowing through the second cooling path and reaching the confluence to the second radiator side. .

  The engine cooling system may further include a check valve that is provided downstream of the branch point in the circulation direction of the second cooling path and prevents the cooling water from flowing backward.

  The engine cooling system is provided between the branch point and the junction point located downstream of the branch point in the circulation direction of the first cooling path, and flows through the second cooling path. In addition, a check valve may be further provided to prevent the cooling water reaching the junction from flowing back to the branch point.

  According to the present invention, there is an effect that the flow rate of the cooling water flowing through the second cooling path can be stabilized.

It is a mimetic diagram showing composition of engine cooling system S concerning a 1st embodiment. FIG. 4 is a diagram for explaining a configuration of a branching / merging unit 30. FIG. 6 is a schematic diagram for explaining a configuration of a first modified example of the branch junction unit 30. FIG. 6 is a schematic diagram for explaining a configuration of a second modified example of the branch junction unit 30. It is a schematic diagram which shows the structure of the engine cooling system S which concerns on 2nd Embodiment. 3 is a schematic diagram showing a configuration of a check valve 60. FIG. It is a schematic diagram which shows the structure of the engine cooling system S which concerns on 3rd Embodiment. FIG. 3 is a schematic diagram showing the configuration of a branch point 34, a junction point 35, and a check valve 70.

<First Embodiment>
The configuration of the engine cooling system S according to the first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a schematic diagram showing a configuration of an engine cooling system S according to the first embodiment.

  The engine cooling system S is mounted on a vehicle having an engine that is an internal combustion engine. For example, the engine cooling system S cools the engine using cooling water circulated between the engine and the main radiator. Further, the engine cooling system S cools the intake air taken into the engine by the cooling water cooled to a low temperature by the sub radiator.

  As shown in FIG. 1, the engine cooling system S includes an engine 10, a main cooling path 20, a main radiator 22, a main pump 24, a flow rate adjusting valve 26, a heater core 28, a sub cooling path 40, It has a radiator 42, a sub pump 44, an intercooler 46, another water-cooled heat exchanger 48, and a control unit 90. In the present embodiment, the main cooling path 20 corresponds to the first cooling path, the sub cooling path 40 corresponds to the second cooling path, the main radiator 22 corresponds to the first radiator, and the sub radiator 42 corresponds to the second cooling path. The main pump 24 corresponds to the first pump, and the sub pump 44 corresponds to the second pump.

  The engine 10 is a diesel engine, for example, and includes a plurality of cylinders. The engine 10 generates power by burning and expanding a mixture of fuel and intake air (air) in a cylinder. The intake air is drawn into the cylinders of the engine 10 through an intake passage (not shown). The intake air is compressed by a compressor of a supercharger provided in the intake passage. Further, the engine 10 discharges the exhaust (exhaust gas) after combustion through the exhaust passage.

  The main cooling path 20 is a path for circulating the cooling water of the engine 10 between the engine 10 and the main radiator 22. The main cooling path 20 is indicated by a bold line in FIG. The main cooling path 20 is provided so that the cooling water passes through the engine 10, and the cooling water takes the heat of the engine 10 to lower the temperature of the engine 10.

  The main radiator 22 is provided on the downstream side of the engine 10 in the circulating direction of the cooling water in the main cooling path 20, and cools the cooling water that has passed through the engine 10. The main radiator 22 has a fan that cools cooling water, for example. Further, the main radiator 22 may cool the cooling water with wind from the front of the vehicle.

  The main pump 24 is provided on the downstream side of the main radiator 22 in the circulating direction of the cooling water in the main cooling path 20, and circulates the cooling water in the main cooling path 20. As the main pump 24 rotates, the cooling water circulates through the main cooling path 20.

  The flow rate adjustment valve 26 is provided so as to branch the main cooling path 20 between the engine 10 and the main radiator 22, and adjusts the flow rate of the cooling water that has passed through the engine 10 to the main radiator 22. Thereby, since the flow volume of the cooling water cooled with the main radiator 22 can be adjusted, the temperature of the cooling water in the main cooling path | route 20 can also be adjusted.

  The heater core 28 exchanges heat between the cooling water that has passed through the engine 10 and the air. Thereby, the air which exchanged heat with the high-temperature cooling water that has passed through the engine 10 is warmed, and the interior of the vehicle can be heated. The heater core 28 has a tube inside, for example, and heat-exchanges the cooling water and air which flow through the tube.

  The sub-cooling path 40 is a path that branches from the main cooling path 20 at a branch point and joins the main cooling path 20 at the junction point, and circulates a part of the cooling water in the main cooling path 20. In the present embodiment, the sub-cooling path 40 branches from the main cooling path 20 at the branch / merging section 30 where the branch point and the merge point are at the same position, and also joins the main cooling path 20 at the branch / merging section 30. The branch junction 30 is located on the upstream side of the main pump 24 in the main cooling path 20. The sub cooling path 40 has a small diameter so that a smaller amount of cooling water flows than the main cooling path 20.

  FIG. 2 is a diagram for explaining the configuration of the branching / merging unit 30. The arrows shown in FIG. 2 indicate the flow of cooling water. As shown in FIG. 2, the branching / merging portion 30 branches so as to be orthogonal to all four directions. Specifically, the branch merging portion 30 is a portion where the connecting pipe 21a and the connecting pipe 21b of the main cooling path 20 and the connecting pipe 41a and the connecting pipe 41b of the sub cooling path 40 are connected. The connecting pipe 41a and the connecting pipe 41b are orthogonal to the connecting pipe 21a and the connecting pipe 21b. For convenience of drawing, the orientations of the connecting pipes 21a, 21b, 41a, 41b in FIG. 1, which are schematic diagrams, are different from the orientations of the connecting pipes 21a, 21b, 41a, 41b in FIG.

  As shown in FIG. 2, the cooling water that has passed through the main radiator 22 and reached the branching / merging portion 30 via the connecting pipe 21a branches off at the branching / merging portion 30 and is sent to the engine 10 via the connecting pipe 21b. Or, it is sent to the sub-radiator 42 via the connecting pipe 41b. Further, as shown in FIG. 2, the cooling water that has reached the branch merging section 30 from the connection pipe 41a of the sub cooling path 40 merges with the cooling water that has flowed from the connection pipe 21a in the branch merging section 30, and the connection pipe It is sent to the engine 10 via 21b.

  When the branch point and the merge point are at the same position as in this embodiment, no pressure loss due to resistance between the branch point and the merge point that occurs when the branch point and the merge point are separated, Since fluctuations in the pump load can also be suppressed, the branching and merging of the cooling water in the merging / merging portion 30 are appropriately performed. Further, since the connecting pipe 21b provided with the main pump 24 is orthogonal to the connecting pipes 41a and 41b of the sub cooling path 40, the flow of the cooling water in the connecting pipes 41a and 41b is caused by the rotation of the main pump 24. Fluctuation can be suppressed.

  Returning to FIG. 1, the sub-radiator 42 is provided in the sub-cooling path 40 and cools the cooling water to a low temperature. For example, the sub radiator 42 further cools a part of the cooling water cooled by the main radiator 22.

  The sub pump 44 is provided on the downstream side of the sub radiator 42 in the sub cooling path 40, and circulates the cooling water in the sub cooling path 40. In the present embodiment, the sub pump 44 has a function of controlling the flow rate of the cooling water in the sub cooling path 40. For example, the sub pump 44 controls the flow rate of the cooling water by changing the rotation speed. The sub pump 44 is, for example, an electric pump. For this reason, the sub pump 44 can finely control the flow rate of the cooling water by performing stop, intermittent operation, continuous operation, variable operation, and the like. As a result, it becomes easy to stabilize the flow rate of the cooling water flowing through the sub cooling path 40.

  In order to adjust the flow rate of the cooling water, there may be a measure of providing a sub-cooling path 40 with a thermostat that adjusts the flow rate according to the temperature of the cooling water, but the cooling water flows even if the thermostat is closed. Further, in the case of a thermostat, it is difficult to stabilize the flow rate of the cooling water because the flow rate of the cooling water cannot be controlled more finely than the electric pump.

  The intercooler 46 is provided on the downstream side of the sub pump 44, and cools the intake air flowing through the intake passage (not shown) with the cooling water that has passed through the sub radiator 42. As a result, the intake air compressed to a high temperature by the compressor of the supercharger in the intake passage can be cooled and supplied to the engine 10. A thermostat 47 is provided on the downstream side of the intercooler 46, and the flow rate of the cooling water that passes through the intercooler 46 is controlled according to the temperature of the cooling water that has passed through the intercooler 46.

  The other water-cooled heat exchanger 48 is a condenser (condenser) of a car air conditioner that cools the inside of the vehicle with a refrigerant, for example, and condenses the refrigerant with the cooling water that has passed through the sub-radiator 42. In the present embodiment, the other water-cooled heat exchanger 48 is provided in the sub-cooling path 40. However, the present invention is not limited to this, and the other water-cooled heat exchanger 48 may not be provided.

  The control unit 90 is configured by a CPU, for example, and controls the operation of the engine cooling system S. For example, the control unit 90 controls the operation of the main pump 24 and the sub pump 44 to control the flow rate of the cooling water flowing through the main cooling path 20 and the sub cooling path 40.

(Modification of branch junction 30)
In the engine cooling system S described above, because the branch / merging portion 30 is close to the main pump 24, the cooling water reaching the branch / merging portion 30 from the connection pipe 41a of the sub-cooling path 40 due to pressure fluctuation or pulsation of the flow rate. There is a risk of flowing to the connecting pipe 41b without flowing to the connecting pipe 21b. In the present embodiment, in order to prevent the cooling water from flowing to the connecting pipe 41b, the branching / merging portion 30 may have the configuration shown in FIG. 3 or FIG.

  FIG. 3 is a schematic diagram for explaining the configuration of the first modification of the branching / merging unit 30. As shown in FIG. 3, in the first modification, a partition wall 32 is provided along the axial direction inside the connection pipes 21 a and 21 b constituting the branch and merge section 30. The partition wall 32 is orthogonal to the piping direction of the connection pipes 41 a and 41 b of the sub cooling path 40. The partition wall 32 restricts the flow of the cooling water that has flowed through the connection pipe 41a and reached the branching junction 30 to the connection pipe 41b. Thereby, it is possible to prevent the cooling water from flowing from the connecting pipe 41a to the connecting pipe 41b.

  FIG. 4 is a schematic diagram for explaining the configuration of the second modified example of the branching / merging unit 30. As shown in FIG. 4, in the 2nd modification, the connecting pipes 21a and 21b which comprise the branch merge part 30 are double pipes. Specifically, the connecting pipes 21a and 21b are outer pipes, and an inner pipe 33 is provided inside the connecting pipes 21a and 21b. The connecting pipe 41a of the sub cooling path 40 is connected to the inner pipe 33, and the connecting pipe 41b is connected to the connecting pipes 21a and 21b which are outer pipes. Thereby, it can control that the cooling water which flowed through the connection pipe 41a and reached the branch merge part 30 flows into the connection pipe 41b.

(Effect in the first embodiment)
In the engine cooling system S of the first embodiment described above, the branch point and the merge point of the sub cooling path 40 from the main cooling path 20 are located in the branch merge section 30 on the upstream side of the main pump 24. The sub cooling path 40 is provided with a sub pump 44 that controls the flow rate of the cooling water in the sub cooling path 40.
In such a case, since the cooling water is branched and merged in the branch / merging section 30, the branching and merging points are provided on the upstream side and the downstream side of the main pump 24, respectively. The influence on the flow of cooling water can be suppressed. In addition, since the sub pump 44 can perform, for example, intermittent operation, continuous operation, variable operation, and the like, it becomes easy to adjust the flow rate of the cooling water in the sub cooling path 40, so the flow rate of the cooling water in the sub cooling path 40 can be stabilized. .

<Second Embodiment>
The configuration of the engine cooling system S according to the second embodiment will be described with reference to FIGS. 5 and 6.

  FIG. 5 is a schematic diagram showing the configuration of the engine cooling system S according to the second embodiment. The second embodiment differs from the first embodiment in that a check valve 60 is provided in the connection pipe 41b of the sub cooling path 40 as shown in FIG. Other configurations are the same as those of the first embodiment. When the branching / merging portion 30 is close to the main pump 24, a flow opposite to the flow from the original branching / merging portion 30 to the connecting pipe 41b may occur due to pressure fluctuation or flow pulsation. Therefore, in the second embodiment, a check valve 60 is provided in order to prevent the backflow of the cooling water.

  FIG. 6 is a schematic diagram showing the configuration of the check valve 60. The check valve 60 has a sphere 62 and a locking portion 64 inside. When the cooling water flows from the branching / merging portion 30 toward the sub-radiator 42 in the connecting pipe 41b, the sphere 62 is locked to the locking portion 64 as shown in FIG. Does not block the flow of On the other hand, when a back flow from the sub-radiator 42 to the branching / merging portion occurs in the connecting pipe 41b, the sphere 62 moves to the opposite side of the locking portion 64 as shown in FIG. By closing the inner flow path, it is possible to prevent the subsequent reverse flow of the cooling water.

<Third Embodiment>
The configuration of the engine cooling system S according to the third embodiment will be described with reference to FIGS. 7 and 8.

  FIG. 7 is a schematic diagram showing a configuration of an engine cooling system S according to the third embodiment. In the third embodiment, unlike the first embodiment in which the branch point and the junction point on the upstream side of the main pump 24 are located in the branch junction unit 30, as shown in FIG. 7, the junction point 35 is a branch point 34. A check valve 70 is provided between the branch point 34 and the junction point 35, which is located further downstream. As with the check valve 60 of the second embodiment, the check valve 70 also prevents a backflow of cooling water. Specifically, the check valve 70 allows the cooling water flowing through the connecting pipe 41a to the junction 35 to flow back to the branch point 34 when the main pump 24 is stopped and the sub pump 44 is rotating. To prevent.

  FIG. 8 is a schematic diagram showing the configuration of the branch point 34, the junction point 35, and the check valve 70. As shown in FIG. 8, the check valve 70 is provided in the connection pipe 21 c between the connection pipe 21 a and the connection pipe 21 b, and has a spherical body 62 and a locking portion 64, similar to the check valve 60 of FIG. 6. . When the cooling water flows from the branch point 34 to the merge point 35, the flow of the cooling water is not blocked because the sphere 62 is locked to the locking portion 64 as shown in FIG. . On the other hand, when a backflow from the junction 35 to the branch point 34 occurs, the sphere 62 moves to the opposite side of the locking portion 64 as shown in FIG. Then, the back flow of the cooling water can be prevented.

  Further, according to the third embodiment, even when the main pump 24 is stopped and the cooling water is not circulated, the cooling water flows from the sub cooling path 40 to the main cooling path 20 by the rotation of the sub pump 44. The heat generated by the feeder can be taken away.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Engine 20 Main cooling path 22 Main radiator 24 Main pump 30 Branch and junction part 32 Bulkhead 40 Sub cooling path 42 Sub radiator 44 Sub pump 60,70 Check valve S Engine cooling system

Claims (4)

A first cooling path through which engine cooling water circulates;
A first radiator provided in the first cooling path for cooling the cooling water that has passed through the engine;
A first pump provided in the first cooling path for circulating the cooling water;
The first cooling path branches from the first cooling path at a branch point upstream of the first pump in the circulation direction of the first cooling path, and the first cooling path at a junction point upstream of the first pump in the circulation direction. A second cooling path that merges with
A second radiator that is provided in the second cooling path and further cools a part of the cooling water cooled by the first radiator;
A second pump that is provided in the second cooling path and controls a flow rate of the cooling water in the second cooling path;
Equipped with a,
The first cooling path is provided with a branch merging portion branched so as to be orthogonal to four directions so that the branch point and the merging point are at the same position.
A partition along the axial direction is provided in the branching / merging portion in order to restrict the cooling water flowing through the second cooling path and reaching the joining point from flowing to the second radiator side.
Engine cooling system. A first cooling path through which engine cooling water circulates;
A first radiator provided in the first cooling path for cooling the cooling water that has passed through the engine;
A first pump provided in the first cooling path for circulating the cooling water;
The first cooling path branches from the first cooling path at a branch point upstream of the first pump in the circulation direction of the first cooling path, and the first cooling path at a junction point upstream of the first pump in the circulation direction. A second cooling path that merges with
A second radiator that is provided in the second cooling path and further cools a part of the cooling water cooled by the first radiator;
A second pump that is provided in the second cooling path and controls a flow rate of the cooling water in the second cooling path;
With
The first cooling path is provided with a branch merging portion branched so as to be orthogonal to four directions so that the branch point and the merging point are at the same position.
The branching / merging portion is a double pipe in order to restrict the cooling water that has flowed through the second cooling path and reached the merging point from flowing to the second radiator side,
Engine cooling system. A first cooling path through which engine cooling water circulates;
A first radiator provided in the first cooling path for cooling the cooling water that has passed through the engine;
A first pump provided in the first cooling path for circulating the cooling water;
The first cooling path branches from the first cooling path at a branch point upstream of the first pump in the circulation direction of the first cooling path, and the first cooling path at a junction point upstream of the first pump in the circulation direction. A second cooling path that merges with
A second radiator that is provided in the second cooling path and further cools a part of the cooling water cooled by the first radiator;
A second pump that is provided in the second cooling path and controls a flow rate of the cooling water in the second cooling path;
With
The first cooling path is provided with a branch merging portion branched so as to be orthogonal to four directions so that the branch point and the merging point are at the same position.
Further provided with a check valve provided downstream of the branch point in the circulation direction of the second cooling path to prevent the cooling water from flowing backward.
Engine cooling system. A first cooling path through which engine cooling water circulates;
A first radiator provided in the first cooling path for cooling the cooling water that has passed through the engine;
A first pump provided in the first cooling path for circulating the cooling water;
The first cooling path branches from the first cooling path at a branch point upstream of the first pump in the circulation direction of the first cooling path, and the first cooling path at a junction point upstream of the first pump in the circulation direction. A second cooling path that merges with
A second radiator that is provided in the second cooling path and further cools a part of the cooling water cooled by the first radiator;
A second pump that is provided in the second cooling path and controls a flow rate of the cooling water in the second cooling path;
Cooling provided in the circulation direction of the first cooling path between the branch point and the junction point located downstream of the branch point and flowing through the second cooling path to the junction point A check valve for preventing water from flowing back to the branch point;
Comprising
Engine cooling system.

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