JP2013199853A - Cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool an engine and a transaxle in a hybrid vehicle, and to achieve a miniaturization of a device.SOLUTION: A cooling device is provided with a communication flow path 50 connecting a point P1 of a cooling water circulation flow path 36 of an engine cooling system 30 between an engine 22 and a radiator 32 with a point P2 between a heat exchanger 34 and the engine 22. flow path switch valves 52, 54 are mounted at the points P1, P2. An electric pump 38 capable of performing normal rotation and reverse rotation is mounted between the heat exchanger 34 and the point P2. When the engine 22 is stopped and the temperature of oil of a transaxle cooling system 60 is higher than the temperature of cooling water of the engine cooling system 30, the flow path switch valves 52, 54 are driven and the electric pump 38 is reversely driven so that the cooling water flows in the order of the electric pump 38, the heat exchanger 34, the radiator 32, the point P1, the communication flow path 50, the point P2, and the electric pump 38.

Description

  The present invention relates to a cooling device, and more specifically, the engine is mounted on a hybrid vehicle having an engine and a transaxle including a motor, and a first cooling medium is circulated through a first circulation passage that circulates between the engine and the radiator. A second cooling medium is circulated in a second circulation path that circulates between an engine cooling system that cools the engine, a heat exchanger for exchanging heat with the first cooling medium in the first circulation path, and a transaxle. The present invention relates to a cooling device including a transaxle cooling system for cooling an axle.

  Conventionally, as this type of cooling device, in a device that pumps cooling water by an electric pump to a circulation passage that circulates a motor, an inverter, and a radiator, a first bypass passage that bypasses the motor and the inverter are bypassed. Providing a second bypass flow path and a third bypass flow path for bypassing the radiator has been proposed (see, for example, Patent Document 1). In this apparatus, when the temperature of the inverter is lower than the threshold value, the valve is switched so that the cooling water flows into the second bypass flow path, so that the cooling water does not flow through the inverter.

JP 2007-202244 A

  A hybrid vehicle equipped with an engine and a transaxle including a motor needs to be equipped with an engine cooling system and a transaxle cooling system. It becomes difficult to install. To solve this problem, it is conceivable that the oil is cooled by cooling water by heat exchange between the oil as the heat exchange medium of the transaxle cooling system and the cooling water as the heat exchange medium of the engine cooling system, but the engine is stopped. When the motor travels using the power from the motor in this state, the engine is stopped, so that the cooling water in the engine cooling system does not flow and the oil cannot be sufficiently cooled. Further, in so-called plug-in hybrid vehicles, the frequency of motor travel increases, so that it is necessary to enhance the cooling performance and reduce the weight during motor travel.

  The cooling device of the present invention is mainly intended to efficiently cool an engine and a transaxle in a hybrid vehicle and to reduce the size of the device.

  The cooling device of the present invention employs the following means in order to achieve the main object described above.

The cooling device of the present invention comprises:
An engine cooling system that is mounted on a hybrid vehicle having an engine and a transaxle including a motor, and that cools the engine by circulating a first cooling medium in a first circulation passage that circulates between the engine and the radiator; A second circulation passage that is attached to the vicinity of the radiator in the passage from the radiator to the engine in the first circulation passage and circulates through the heat exchanger that exchanges heat with the first cooling medium, and the transaxle. A transaxle cooling system for cooling the transaxle by circulating two cooling media,
The first circulation flow path has a communication flow path for connecting a first point provided between the engine and the radiator and a second point provided between the heat exchanger and the engine. And
The cooling device is
Forward rotation and the first cooling medium, which are attached between the heat exchanger and the second point of the first circulation flow path, and which pump the first cooling medium from the heat exchanger side to the second point side An electric pump capable of reversing to pump from the second point side to the heat exchanger side,
A first flow path switching valve attached to the first point;
A second flow path switching valve attached to the second point;
When the engine is shut down and the temperature of the second coolant is higher than the temperature of the first coolant, the first coolant is the electric pump, the heat exchanger, the radiator, the first The first flow path switching valve and the second flow path switching valve are driven and controlled so as to circulate in the order of 1 point, the communication flow path, the second point, and the electric pump. Control means for driving and controlling the electric pump;
It is a summary to provide.

  In the cooling device of the present invention, the first point provided between the engine and the radiator and the second point provided between the heat exchanger and the engine are connected to the first circulation flow path of the engine cooling system. And a first flow path switching valve and a second flow path switching valve are attached to the first point and the second point, and the first cooling medium is moved from the heat exchanger side to the second point side. An electric pump capable of normal rotation for pumping and reverse rotation for pumping the first cooling medium from the second point side to the heat exchanger side is attached between the heat exchanger of the first circulation flow path and the second point. When the engine is stopped and the temperature of the second cooling medium is higher than the temperature of the first cooling medium, the first cooling medium is an electric pump, a heat exchanger, a radiator, a first point, a communication channel. The first flow path switching valve and the second flow path switching valve are driven and controlled so as to circulate in the order of the second point and the electric pump, and the electric pump is reversely driven. As a result, even when the engine is shut down and cooling of the engine is not required, the first cooling medium of the engine cooling system is circulated through the heat exchanger, the radiator, and the communication flow path so that the transaxle cooling system is used in the heat exchanger. The second cooling medium can be cooled. As a result, it is possible to improve the cooling performance of the transaxle when the engine is stopped. Further, since the electric pump is reversed when the temperature of the second cooling medium is higher than the temperature of the first cooling medium, the temperature of the second cooling medium becomes equal to or lower than the temperature of the first cooling medium, and the second cooling medium is cooled to the first cooling medium. It is possible to prevent wasteful reversal of the electric pump when the medium cannot be cooled. Of course, since the second cooling system of the transaxle cooling system is cooled by the first cooling medium of the engine cooling system, the apparatus can be reduced in size and weight.

  In the cooling device of the present invention, when the engine is operating, the control means is configured such that the first cooling medium is the electric pump, the second point, the engine, the first point, the radiator, and the heat. A means for driving and controlling the first flow path switching valve and the second flow path switching valve so as to circulate in the order of the exchanger and the electric pump, and for driving and controlling the electric pump so that the electric pump rotates forward. Can also be.

  In the cooling device of the present invention, the first circulation flow path is provided between a third point provided between the first point and the engine, the electric pump, and the heat exchanger. A bypass flow path communicating with the fourth point, and the flow of the first cooling medium in the bypass flow path from the third point to the fourth point is allowed but from the fourth point to the third point And a reverse flow prevention valve for prohibiting the flow to the first point, and the first cooling from the engine when the temperature of the first cooling medium flowing through the third point is lower than a predetermined threshold temperature. When the medium flows through the bypass flow path and the temperature of the first cooling medium flowing through the third point is equal to or higher than the threshold temperature, the first cooling medium from the engine is A third flow path switching valve for switching the flow path to flow to the other side, can also be made with a. In this way, the engine can be warmed up quickly and the engine can be efficiently cooled.

It is a block diagram which shows the outline of a structure of the cooling device 20 as one Example of this invention. It is explanatory drawing which shows an example of the engine cooling flow path which does not use the bypass flow path. 4 is an explanatory diagram showing an example of an engine cooling channel using a bypass channel 40. FIG. It is explanatory drawing which shows an example of the flow path for engine detours. 3 is a flowchart showing an example of a flow control routine executed by a control device 70.

  Next, the form for implementing this invention is demonstrated using an Example.

FIG. 1 is a configuration diagram showing an outline of a configuration of a cooling device 20 as an embodiment of the present invention.
The cooling device 20 according to the embodiment is mounted on a hybrid vehicle including an engine 22 and a transaxle 24 including a travel motor (not shown). The engine cooling system 30 that cools the engine 22 and the transaxle 24 are cooled. A transaxle cooling system 60 that controls the flow of cooling water in the engine cooling system 30.

  The engine cooling system 30 includes a radiator 32 that cools cooling water as a cooling medium by outside air, a cooling water circulation passage 36 that circulates through the engine 22, a downstream side of the radiator 32 in the cooling water circulation passage 36, and the radiator 32. A heat exchanger 34 disposed in the lower portion for cooling oil as a cooling medium of the transaxle cooling system 60; a point P1 between the engine 22 and the radiator 32 in the cooling water circulation passage 36; and a heat exchanger 34 Attached to points P1 and P2 to switch between the communication flow path 50 communicating with the point P2 between the engine 22 and the flow of cooling water in the cooling water circulation flow path 36 and the flow of cooling water to the communication flow path 50. Are installed between the heat exchanger 34 and the point P2 of the flow path switching valves 52, 54 and the cooling water circulation flow path 36, and the cooling water is supplied to the heat exchanger 34 side. It comprises a forward pumping to Luo point P2 side and the cooling water heat exchanger 34 reversed and capable electric pump for pumping the side 38 from the point P2 side. Further, in order to bypass the radiator 32, the engine cooling system 30 includes a point P3 between the engine 22 and the point P1 in the cooling water circulation passage 36 and a point P4 between the heat exchanger 34 and the electric pump 38. When the temperature of the cooling water to be communicated with the bypass flow path 40 is lower than a predetermined threshold temperature, the cooling water from the engine 22 is caused to flow into the bypass flow path 40, and when the temperature of the cooling water is equal to or higher than the threshold temperature, The thermostat switching valve 42 attached to the point P3 for flowing the cooling water to the radiator 32 side and the flow of the cooling water from the point P3 side to the point P4 side of the bypass passage 40 are permitted, but the point from the point P4 side is permitted. A backflow prevention valve 44 that prohibits the flow to the P3 side is provided.

  In the engine cooling system 30, the thermostat type switching based on the temperature of the cooling water is performed by switching the flow path switching valves 52 and 54 so that the cooling water does not flow into the communication flow path 50 and driving the electric pump 38 to rotate forward. By switching by the valve 42, the cooling water flows in the cooling water circulation passage 36 in the order of the electric pump 38, the engine 22, the radiator 32, the heat exchanger 34, and the electric pump 38 as shown in FIG. 2, or as shown in FIG. The cooling water flows in the order of the electric pump 38, the engine 22, the point P3, the bypass flow path 40, the point P4, the heat exchanger 34, and the electric pump 38, and forms a flow path for engine cooling. By switching the valves 52 and 54 so that the cooling water flows into the communication flow path 50 and driving the electric pump 38 in the reverse direction. Cooling water electric pump 38 as shown in FIG. 4, the heat exchanger 34, a radiator 32, point P1, communication channel 50, point P2, to form the engine bypass flow path that flows in the order of the electric pump 38.

  The transaxle cooling system 60 includes an oil circulation passage 62 through which oil as a cooling medium cooled by heat exchange with the cooling water of the engine cooling system 30 circulates between the transaxle 24 and the heat exchanger 34. The motor that constitutes the transaxle 24 and the inverter as the motor drive circuit are cooled.

  Although not shown, the control device 70 is configured as a microcomputer centered on a CPU, and includes a ROM for storing processing programs, a RAM for temporarily storing data, an input / output port, a communication port, and the like. The control device 70 is attached to, for example, the cooling water temperature Tw from the temperature sensor 72 attached to the cooling water flow path of the engine 22 or the oil flow path into which oil that has cooled the motor of the transaxle 24 flows into the oil pan, for example. The oil temperature Toil from the temperature sensor 74 is input, and the control device 70 outputs a drive signal to the electric pump 38, a drive signal to the flow path switching valves 52 and 54, and the like.

  Next, the operation of the cooling device 20 configured as described above, particularly the operation during the running of the motor that stops the operation of the engine 22 and runs by the power from the running motor will be described. FIG. 5 is a flowchart illustrating an example of a flow control routine executed by the control device 70.

  When the flow control routine is executed, the control device 70 first controls the flow of the cooling water flowing through the cooling water circulation passage 36 such as the cooling water temperature Tw from the temperature sensor 72 and the oil temperature Toil from the temperature sensor 74. A process of inputting necessary data is executed (step S100). Subsequently, it is determined whether or not the operation of the engine 22 is stopped (step S110) and whether or not the input oil temperature Toil is higher than the coolant temperature Tw (step S120).

  As shown in FIG. 2, when the oil temperature Toil is equal to or lower than the cooling water temperature Tw even when the engine 22 is operated or the engine 22 is stopped, switching is performed by the thermostat switching valve 42 based on the cooling water temperature. Cooling water flows through the cooling water circulation passage 36 in the order of the electric pump 38, the engine 22, the radiator 32, the heat exchanger 34, and the electric pump 38, or as shown in FIG. 3, the cooling water flows through the electric pump 38, the engine 22, and the point P3. , Bypass flow path 40, point P4, heat exchanger 34, and electric pump 38 are flowed in this order, or flow path switching valves 52, 54 are driven so that any engine cooling flow path is formed (step S130). Then, the electric pump 38 is driven forward so that the cooling water flows from the heat exchanger 34 side to the point P2 side (step S140). To end the present routine. The electric pump 38 is normally driven as an engine cooling flow path that does not use the bypass flow path 40 shown in FIG. 2, thereby cooling the cooling water for cooling the engine 22 using the outside air by the radiator 24 and the transaxle cooling system. The oil as 60 cooling medium can be cooled by cooling water. In addition, the engine 22 can be warmed up quickly by driving the electric pump 38 to rotate forward as an engine cooling channel using the bypass channel 40 shown in FIG.

  On the other hand, when the operation of the engine 22 is stopped in steps S110 and S120 and the oil temperature Toil is higher than the cooling water temperature Tw, the cooling water is supplied to the electric pump 38, the heat exchanger 34, and the radiator 32 as shown in FIG. , Point P1, communication flow path 50, point P2, and the flow path switching valves 52 and 54 are driven so as to form an engine bypass flow path that flows in the order of the electric pump 38 (step S150). The electric pump 38 is reversely driven so as to flow to the heat exchanger side (step S160), and this routine is terminated. By controlling in this way, even when the engine 22 is not operating, the oil as the cooling medium of the transaxle cooling system 60 can be cooled by the cooling water.

  According to the cooling device 20 of the embodiment described above, the radiator 32 of the cooling water circulation passage 36 that circulates the radiator 32 of the engine cooling system 30 and the radiator 32 of the engine cooling system 30 through the heat exchanger 34 in which the oil as the cooling medium of the transaxle 24 circulates. The communication flow path 50 is provided immediately after the point 32 to connect the point P1 between the engine 22 and the radiator 32 and the point P2 between the heat exchanger 34 and the engine 22 in the cooling water circulation path 36. The flow path switching valves 52 and 54 are attached to P1 and P2, the electric pump 38 capable of normal rotation and reverse rotation is attached between the heat exchanger 34 and the point P2, the engine 22 is stopped, and When the oil temperature Toil is higher than the cooling water temperature Tw, the cooling water is the electric pump 38, the heat exchanger 34, the radiator 32, the point P1, The flow path switching valves 52 and 54 are driven and controlled so that an engine bypass flow path that flows in the order of the tangled flow path 50, the point P2, and the electric pump 38, and cooling water flows from the heat point P2 side to the heat exchanger side. By driving the electric pump 38 in the reverse direction, the oil as the cooling medium of the transaxle cooling system 60 can be cooled by the cooling water even when the engine 22 is not operating. As a result, the cooling performance of the transaxle 24 when the engine 22 is stopped can be improved. Further, since the electric pump 38 is reversed when the oil temperature Toil is higher than the cooling water temperature Tw, the electric pump 38 is reversed when the oil temperature Toil becomes equal to or lower than the cooling water temperature Tw and the oil cannot be cooled by the cooling water. It is possible to prevent waste. Of course, since the oil of the transaxle cooling system 60 is cooled by the cooling water of the engine cooling system 30, the apparatus can be reduced in size and weight.

  In the cooling device 20 of the embodiment, cooling water is used as the cooling medium of the engine cooling system 30 and oil is used as the cooling medium of the transaxle cooling system. However, any cooling medium may be used as long as it can flow. Any cooling medium may be used.

  In the cooling device 20 of the embodiment, the temperature sensor 72 that detects the cooling water temperature Tw is attached to the cooling water flow path of the engine 22, but the attachment position of the temperature sensor 72 is not limited to this, and the engine 22 is not limited thereto. It may be attached to any position as long as the temperature of the cooling water can be detected, such as the inlet position and the outlet position of the cooling water flow path, or an intermediate position thereof, and the vicinity of the engine 22 of the cooling water circulation flow path 36. . Further, in the cooling device 20 of the embodiment, the temperature sensor 74 for detecting the oil temperature Toil is attached to the oil passage through which the oil that has cooled the motor flows into the oil pan, but the attachment position of the temperature sensor 74 is limited to this. However, the oil pan or a cooling oil may be attached to the transmission when the cooling oil also serves as the lubricating oil of the transmission. Alternatively, the oil temperature Toil may be estimated from the motor temperature, and the estimated oil temperature Toil may be used.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “engine”, the transaxle 24 corresponds to the “transaxle”, the radiator 32 corresponds to the “radiator”, and the cooling water circulation passage 36 becomes the “first circulation passage”. The cooling water corresponds to the “first cooling medium”, the engine cooling system 30 corresponds to the “engine cooling system”, the heat exchanger 34 corresponds to the “heat exchanger”, and the oil circulation channel 62 Corresponds to “second circulation flow path”, oil corresponds to “second cooling medium”, transaxle cooling system 60 corresponds to “transaxle cooling system”, and point P1 corresponds to “first point”. The point P2 corresponds to the “second point”, the communication channel 50 corresponds to the “connection channel”, the electric pump 38 corresponds to the “electric pump”, and the channel switching valve 52 corresponds to the “first channel”. Corresponding to `` switching valve '', flow path switching valve 4 corresponds to a "second channel switching valve", the control unit 70 to perform the flow control routine of FIG. 5 corresponds to the "control means".

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of a cooling device for a hybrid vehicle.

  20 Cooling device, 22 Engine, 24 Transaxle, 30 Engine cooling system, 32 Radiator, 34 Heat exchanger, 36 Cooling water circulation flow path, 40 Bypass flow path, 42 Thermostat switching valve, 44 Backflow prevention valve, 50 Connection flow path , 52, 54 Channel switching valve, 60 Transaxle cooling system, 62 Oil circulation channel, 70 Control device, 72, 74 Temperature sensor.

Claims (1)

An engine cooling system that is mounted on a hybrid vehicle having an engine and a transaxle including a motor, and that cools the engine by circulating a first cooling medium in a first circulation passage that circulates between the engine and the radiator; A second circulation passage that is attached to the vicinity of the radiator in the passage from the radiator to the engine in the first circulation passage and circulates through the heat exchanger that exchanges heat with the first cooling medium, and the transaxle. A transaxle cooling system for cooling the transaxle by circulating two cooling media,
The first circulation flow path has a communication flow path for connecting a first point provided between the engine and the radiator and a second point provided between the heat exchanger and the engine. And
The cooling device is
Forward rotation and the first cooling medium, which are attached between the heat exchanger and the second point of the first circulation flow path, and which pump the first cooling medium from the heat exchanger side to the second point side An electric pump capable of reversing to pump from the second point side to the heat exchanger side,
A first flow path switching valve attached to the first point;
A second flow path switching valve attached to the second point;
When the engine is shut down and the temperature of the second coolant is higher than the temperature of the first coolant, the first coolant is the electric pump, the heat exchanger, the radiator, the first The first flow path switching valve and the second flow path switching valve are driven and controlled so as to circulate in the order of 1 point, the communication flow path, the second point, and the electric pump. Control means for driving and controlling the electric pump;
A cooling device comprising:

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