JP5278294B2 - Vehicle oil circulation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently transmit the heat of a transaxle to oil lubricating an internal combustion engine without increasing the number of components. <P>SOLUTION: A first oil circuit circulating the oil lubricating the transaxle 2 and a second oil circuit circulating the oil lubricating the internal combustion engine 1 are partially shared by an oil pan 7, and common oil is used as the oil circulating in these oil circuits. Then, the heat of the transaxle 2 is efficiently transmitted to the oil lubricating the internal combustion engine 1. That is, the heat of the transaxle 2 is directly transferred to the common oil lubricating not only the transaxle 2 but also the internal combustion engine 1, efficiently transferring the heat of the transaxle 2 to the oil lubricating the internal combustion engine 1. Also, a heat exchanger or the like is not needed, when the heat is transferred from the transaxle 2 to the oil, dispensing with a new heat exchanger for transferring the heat. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an oil circulation device for a vehicle.

  Conventionally, a hybrid vehicle in which an internal combustion engine and a motor provided in a transaxle are mounted as a prime mover is known. In such a hybrid vehicle, with the intention of improving the fuel efficiency of the internal combustion engine, the traveling state is switched based on the driving state, for example, between traveling by the internal combustion engine alone, traveling by both the internal combustion engine and the motor, and traveling by the motor alone. I am doing so. The hybrid vehicle is also provided with a first oil circuit for circulating oil for lubricating the transaxle and a second oil circuit for circulating oil for lubricating the internal combustion engine.

  By the way, in a hybrid vehicle, there are many situations in which the internal combustion engine stops during operation due to the switching of the running state as described above, and heat generation in the engine is reduced, while the motor is driven during operation. There is a tendency to generate more heat in the same motor. Therefore, although the oil in the first oil circuit that lubricates the transaxle provided with the motor is likely to increase in temperature, the oil in the second oil circuit that lubricates the internal combustion engine is less likely to increase in temperature, and the viscosity of the oil is reduced. The engine is maintained at a high state and causes an increase in rotational resistance of the internal combustion engine, which hinders improvement of fuel consumption in the engine.

  Therefore, in the hybrid vehicle, there is a demand for transferring the heat generated in the transaxle to the internal combustion engine and its oil. As shown in Patent Document 1, heat exchange is performed between the transaxle and the internal combustion engine. Can be considered. In Patent Document 1, heat exchange is performed through a heat exchanger between cooling water that circulates through an internal combustion engine and oil that lubricates the engine, and between the cooling water and oil that lubricates the transaxle. It is disclosed to exchange heat through a heat exchanger.

  When such a technique of Patent Document 1 is applied to the hybrid vehicle, heat exchange is performed between the cooling water circulating through the internal combustion engine and the oil circulating through the second oil circuit through the heat exchanger, and Heat exchange is performed through the heat exchanger between the cooling water and the oil circulating in the first oil circuit. In this case, when the temperature of the oil circulating through the first oil circuit rises due to heat generated by the transaxle, the heat of the oil is transmitted to the cooling water circulating through the internal combustion engine through the heat exchanger, thereby Is heated up. Then, the heat of the raised cooling water is transmitted to the internal combustion engine and is also transmitted to the oil in the second oil circuit through the heat exchanger, whereby the temperature of the oil is increased.

JP 2001-280133 A (paragraph [0003])

  As described above, by using the technique of Patent Document 1, the heat of the transaxle can be transmitted to the internal combustion engine and its oil. However, in order to transfer the heat of the transaxle to the internal combustion engine and its oil in this way, a heat exchanger that performs heat exchange between the cooling water circulating through the internal combustion engine and the oil of the first oil circuit, and Two heat exchangers such as a heat exchanger for exchanging heat between the cooling water and the oil in the second oil circuit must be provided, and the number of parts is inevitable. In addition, the heat transfer must be performed through cooling water that circulates through the internal combustion engine, and the heat transfer efficiency is reduced by that amount, so that the oil (the second oil circuit of the second oil circuit) is lubricated. It takes a long time to raise the temperature of the oil and reduce the viscosity of the oil. And since the time until it lowers the viscosity of the oil which lubricates an internal combustion engine becomes long, the fuel consumption improvement of the engine is prevented.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hybrid capable of efficiently transmitting the heat of the transaxle to the oil for lubricating the internal combustion engine without increasing the number of parts. An object of the present invention is to provide an oil circulation device for a vehicle.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, according to the first aspect of the present invention, there is provided an oil circulation device for a hybrid vehicle equipped with an internal combustion engine and a motor provided in a transaxle as a prime mover, and circulates oil for lubricating the transaxle. A first oil circuit that circulates oil and a second oil circuit that circulates oil that lubricates the internal combustion engine, and a part of the first oil circuit and the second oil circuit is shared, A common oil is used as the circulating oil, and the circulation of oil in the first oil circuit and the circulation of oil in the second oil circuit are performed by at least one oil pump. The oil after lubricating the transaxle through the circulation of oil and the internal combustion through the circulation of oil in the second oil circuit The oil after lubricating the oil flows down to the common oil pan, and the oil after lubricating the transaxle through the oil circulation in the first oil circuit flows inside the oil pan. Oil level rise of oil accumulated in the second oil pool portion is partitioned into a pool portion and a second oil pool portion in which oil flows after lubricating the internal combustion engine through oil circulation in the second oil circuit. The oil can flow down to the first oil reservoir, and the oil pump sucks up the oil accumulated in the first oil reservoir and sends it to the internal combustion engine and the transaxle. It was.

  In a vehicle equipped with only an internal combustion engine as a prime mover, the internal combustion engine generates a large amount of heat, and the temperature of oil that lubricates the engine tends to be higher than the temperature of oil that lubricates the transaxle. For this reason, the oil that lubricates the internal combustion engine and the oil that lubricates the transaxle are separated, and the oil that lubricates the internal combustion engine is oil that lubricates the transaxle in order to ensure the viscosity of the oil necessary for the lubrication during normal use. More viscous. However, in a hybrid vehicle, since the heat generated from the internal combustion engine is small and the heat generated from the transaxle provided with the motor is large, the temperature of the oil that lubricates the engine and the temperature of the oil that lubricates the transaxle are approximately the same. Value, making it possible for the oils to be the same. According to the above configuration, a part of the first oil circuit that circulates the oil that lubricates the transaxle and the second oil circuit that circulates the oil that lubricates the internal combustion engine are shared, and the oil that circulates in the oil circuit is shared. Since the common oil is used, the heat of the transaxle is efficiently transmitted to the oil that lubricates the internal combustion engine. That is, since the heat of the transaxle is directly transmitted to the common oil that lubricates not only the transaxle but also the internal combustion engine, the heat of the transaxle can be efficiently transmitted to the oil that lubricates the internal combustion engine. . In addition, since it is not necessary to use a heat exchanger or the like when transferring heat from the transaxle to the oil, it is not necessary to provide a new heat exchanger to transfer the heat. In order to realize the above, the number of parts is not increased.

According to the above configuration, the oil accumulated in the oil pan is sucked up by the oil pump, discharged from the oil pump, lubricates the transaxle and the internal combustion engine, and then flows down from the transaxle and the internal combustion engine to the oil pan. . As can be seen from this, the oil circulating in the first oil circuit returns to the oil pan through the oil pan, the oil pump, and the transaxle. The oil circulating in the second oil circuit returns to the oil pan through the oil pan, the oil pump, and the internal combustion engine. Therefore, a part of the first oil circuit and the second oil circuit can be shared by the oil pan. Further, according to the above configuration, when the oil pump is driven, the oil accumulated in the first oil pool is sucked up and discharged toward the transaxle and the internal combustion engine. The oil sent to the transaxle flows down to the first oil pool after lubricating the transaxle, and the oil sent to the internal combustion engine flows down to the second oil pool after lubricating the engine. When the oil level of the oil accumulated in the second oil pool rises, the oil flows down to the first oil pool. Accordingly, the oil circulating in the first oil circuit returns to the first oil pool through the first oil pool, the oil pump, and the transaxle. The oil circulating in the second oil circuit returns to the first oil pool through the first oil pool, the oil pump, the internal combustion engine, and the second oil pool.

In the second aspect of the present invention, the oil circulation system for a hybrid vehicle according to claim 1, one of the oil to both the circulation of the oil in the circulation and the second oil circuit for oil in the first oil circuit a pump, a control valve for opening and closing operation to adjust the flow rate of the oil fed to the internal combustion engine from the oil pump disposed between the oil pump and the internal combustion engine in the second oil circuit, the control during stop of the internal combustion engine by driving the control valves were summarized in that to obtain further Bei and a valve control means for reducing the opening degree of the control valve than during driving of the engine.

According to the above configuration, since the oil is sent to both the internal combustion engine and the transaxle by the common oil pump, two pumps are used as in the case where the oil pump is separately sent to the internal combustion engine and the transaxle. The number of oil pumps can be reduced to one and the number of parts can be reduced.

  Here, while the internal combustion engine is stopped, traveling is performed by driving the motor, and heat is generated from the transaxle provided with the motor. At this time, the opening degree of the control valve is made smaller than that during driving of the internal combustion engine, and the flow rate of the oil circulating through the second oil circuit is reduced. Therefore, the oil is mainly circulated in the first oil circuit. The oil is preferentially and effectively heated by the heat of the transaxle. More specifically, a large amount of the oil circulates in the second oil circuit and the heat of the oil is prevented from being taken away by the internal combustion engine, whereby the oil is preferentially and effectively heated by the heat of the transaxle. Is done. Further, during the operation of the internal combustion engine, the opening degree of the control valve is made larger than that during the stop of the internal combustion engine, and the oil in the first oil circuit heated up as described above (more precisely, the first oil pool portion). A large amount of oil collected in the second oil circuit flows into the second oil circuit and is sent to the internal combustion engine. When this is done, the oil that lubricates the internal combustion engine is efficiently heated, and the heat of the transaxle is efficiently transferred to the oil that lubricates the internal combustion engine.

  Therefore, when the internal combustion engine and the transaxle are both started to cool from the state where they are cooled, and the vehicle is shifted from traveling only by driving the motor to traveling using the drive of the internal combustion engine, the following effects can be obtained. In other words, when the vehicle is traveling only by driving the motor immediately after the start of traveling, the oil in the first oil circuit is preferentially and efficiently heated by the heat generated from the motor, and the viscosity of the oil is quickly reduced to an appropriate value. Axle lubrication is suitably performed, and frictional resistance in the transaxle can be reduced. Thereafter, when shifting to driving using the drive of the internal combustion engine, a large amount of the oil in the first oil circuit heated as described above flows into the second oil circuit and is sent to the internal combustion engine. The internal combustion engine is lubricated by the oil whose value has decreased to an appropriate value. As a result, the rotational resistance of the internal combustion engine by the oil can be reduced at an early stage after the driving of the internal combustion engine is started, and appropriate lubrication of the internal combustion engine by the oil can be performed. .

According to a third aspect of the invention, in the first aspect of the invention, a first oil pump that circulates oil in the first oil circuit while the internal combustion engine is being driven or a hybrid vehicle is running, and the internal combustion engine is connected is driven by the rotation of the engine and a second oil pump for circulating the oil in the second oil circuit, before Symbol first oil pump has accumulated in the first oil reservoir section The oil is sucked up and sent to the transaxle to circulate the oil in the first oil circuit, and the second oil pump sucks up the oil accumulated in the first oil pool and sends it to the internal combustion engine. Thus, the gist is to circulate the oil in the second oil circuit.

  According to the above configuration, when the first oil pump is driven, the oil accumulated in the first oil pool is sucked up and discharged toward the transaxle, and after lubricating the transaxle, the oil is collected in the first oil pool. run down. When the second oil pump is driven, the oil accumulated in the first oil pool is sucked up and discharged toward the internal combustion engine, and flows down to the second oil pool after lubricating the engine. When the oil level of the oil accumulated in the second oil pool rises above the protrusion, the oil passes over the protrusion and flows down to the first oil pool. Therefore, the oil circulating in the first oil circuit returns to the first oil pool through the first oil pool, the first oil pump, and the transaxle. The oil circulating in the second oil circuit returns to the first oil pool through the first oil pool, the second oil pump, the internal combustion engine, and the second oil pool.

Here, while the internal combustion engine is stopped, traveling is performed by driving the motor, and heat is generated from the transaxle provided with the motor. At this time, the oil discharge amount of the second oil pump becomes “0”, which is smaller than that during driving of the internal combustion engine, and the flow rate of oil circulating through the second oil circuit is reduced to “0”. Only the oil is circulated in the first oil circuit by driving the oil pump, and the oil is preferentially and effectively heated by the heat of the transaxle. More specifically, a large amount of the oil circulates in the second oil circuit and the heat of the oil is prevented from being taken away by the internal combustion engine, whereby the oil is preferentially and effectively heated by the heat of the transaxle. Is done. Further, since the first oil circuit does not include the entire oil pan but includes only the first oil pool portion, when the oil is circulated in the first oil circuit as described above, the oil is circulated in the first oil circuit. The amount can be reduced, and the temperature of the oil can be increased more rapidly. Further, during the operation of the internal combustion engine, the oil discharge amount of the second oil pump is made larger than the value during the stop of the internal combustion engine (“0”), and the temperature in the first oil circuit heated as described above is increased. A large amount of oil (more precisely, the oil accumulated in the first oil reservoir) flows into the second oil circuit and is sent to the internal combustion engine. When this is done, the oil that lubricates the internal combustion engine is efficiently heated, and the heat of the transaxle is efficiently transferred to the oil that lubricates the internal combustion engine.

  Therefore, when the internal combustion engine and the transaxle are both started to cool from the state where they are cooled, and the vehicle is shifted from traveling only by driving the motor to traveling using the drive of the internal combustion engine, the following effects can be obtained. That is, when the vehicle is traveling only by driving the motor immediately after the start of traveling, the temperature of the oil in the first oil circuit can be raised even more efficiently, and the transaxle can be suitably lubricated with the oil. Reducing the frictional resistance can be realized at an earlier stage. After that, when shifting to running using the drive of the internal combustion engine, the oil in the first oil circuit whose temperature has been raised is sent to the internal combustion engine to lubricate the engine, as described above. It is possible to reduce the rotational resistance of the engine and perform appropriate lubrication early after the start.

1 is a schematic diagram showing an overall configuration of an oil circulation device of the present invention and a hybrid vehicle to which the device is applied. The flowchart which shows the opening / closing control procedure of the control valve provided in the oil circulation apparatus. The time chart which shows the temperature rise aspect of the oil in the 1st oil pool part and the 2nd oil pool part when driving | running | working starts from the state which both the internal combustion engine and the transaxle cooled. The schematic diagram which shows the other example of an oil circulation apparatus.

Hereinafter, an embodiment in which the present invention is embodied in an oil circulation device for a hybrid vehicle will be described with reference to FIGS.
Such a hybrid vehicle is equipped with an internal combustion engine 1 as a prime mover, as shown in FIG. In the hybrid vehicle, a transaxle 2 that transmits the rotation of the internal combustion engine 1 to the wheel side is provided with a gear mechanism 3 that constitutes a planetary gear, a differential gear, etc. for shifting, and motor generators 4 and 5 are also provided. ing.

  The motor generator 5 is for transmitting the rotation to the wheel side to drive the hybrid vehicle, and is mounted on the vehicle as a prime mover different from the internal combustion engine 1. Further, the motor generator 4 adjusts the torque transmitted from the internal combustion engine 1 to the transaxle 2 side through the adjustment of the power generation amount. That is, when the power generation amount of the motor generator 4 is increased, most of the output torque of the internal combustion engine 1 is converted into electric energy by the motor generator 4, and the torque transmitted from the internal combustion engine 1 to the transaxle side is reduced. Conversely, when the power generation amount of the motor generator 4 is reduced, the amount of output torque of the internal combustion engine 1 that is converted into electric energy by the motor generator 4 is reduced, and the torque transmitted from the internal combustion engine 1 to the transaxle side is increased. Become.

  In such a hybrid vehicle, in order to improve the fuel consumption of the internal combustion engine 1, the traveling state is based on the driving state and the like, the traveling by the internal combustion engine 1 alone, the traveling by both the internal combustion engine 1 and the motor generator 5, and only the motor generator 5. Switching between driving by etc. Further, the hybrid vehicle is provided with a first oil circuit for circulating oil for lubricating the transaxle 2 (gear mechanism 3 and the like) and a second oil circuit for circulating oil for lubricating the internal combustion engine 1. Yes.

  Here, compared with such a hybrid vehicle, a vehicle equipped with only an internal combustion engine as a prime mover generates more heat from the internal combustion engine, and the temperature of the oil that lubricates the engine is higher than the temperature of the oil that lubricates the transaxle. Tend to be. For this reason, in an automobile equipped with only an internal combustion engine as a prime mover, the oil that lubricates the internal combustion engine and the oil that lubricates the transaxle are separated, and the internal combustion engine is required to ensure the viscosity of the oil necessary for lubrication during normal use. The oil that lubricates the oil is made more viscous than the oil that lubricates the transaxle.

  However, in a hybrid vehicle, there are many situations in which the internal combustion engine 1 is stopped during operation due to the switching of the running state as described above, and heat generation in the engine 1 is reduced. There are many situations where the generator 5 is driven, and the motor generator 5 tends to generate more heat. For this reason, the temperature of the oil that lubricates the internal combustion engine 1 and the temperature of the oil that lubricates the transaxle 2 are approximately the same value, and the viscosity of the oil for lubricating the internal combustion engine 1 is to lubricate the transaxle 2. It can be as low as the viscosity of the oil, making it possible for the oils to be the same. For this reason, in this embodiment, a part of the first oil circuit for circulating the oil for lubricating the internal combustion engine 1 and the second oil circuit for circulating the oil for lubricating the transaxle 2 are shared. A common oil is used as the oil circulating in the oil circuit.

Next, the oil circulation in the first oil circuit and the second oil circuit and the structure for realizing the oil circulation will be described in detail.
The transaxle 2 is provided with one oil pump 6 that performs both the circulation of oil in the first oil circuit and the circulation of oil in the second oil circuit. The oil pump 6 is driven based on the rotation transmitted from the engine 1 to the transaxle 2 side during operation of the internal combustion engine 1 or the rotation of the transaxle 2 side while the hybrid vehicle is running. On the other hand, rotation transmission from the engine 1 to the transaxle 2 side is not performed while the internal combustion engine 1 is stopped, and rotation on the transaxle 2 side is not generated while the hybrid vehicle is stopped. In this case, the oil pump 6 is not driven and the oil pump 6 stops.

  When the oil pump 6 is driven, the oil accumulated in the oil pan 7 is sucked up by the oil pump 6 and discharged from the oil pump 6. The oil thus discharged from the oil pump 6 is sent to the transaxle 2 through the passage 9 and also sent to the internal combustion engine 1 through the passage 10. The oil sent to the transaxle 2 flows down to the oil pan 7 after lubricating the transaxle 2 (gear mechanism 3 and the like), and the oil sent to the internal combustion engine 1 lubricates the engine 1 and then the oil pan 7 Flow down. A control valve 11 that opens and closes in order to adjust the flow rate of the oil sent from the oil pump 6 to the internal combustion engine 1 is provided in the middle of the passage 10 connecting the oil pump 6 and the internal combustion engine 1 in the second oil circuit. It has been.

  As can be seen from the above, the oil circulating in the first oil circuit returns to the oil pan 7 through the oil pan 7, the oil pump 6, the passage 9, and the transaxle 2. The oil circulating in the second oil circuit returns to the oil pan 7 through the oil pan 7, the oil pump 6, the passage 10, and the internal combustion engine 1. Accordingly, a part of the first oil circuit and the second oil circuit is shared by the oil pan 7. Then, the oil pump 6 is driven to suck up the oil accumulated in the oil pan 7 and send it to the internal combustion engine 1 and the transaxle 2, thereby circulating the oil in the first oil circuit and the oil in the second oil circuit. Both circulation and take place.

  Here, the oil pan 7 has a first oil pool portion in which oil after lubricating the transaxle 2 through the oil circulation in the first oil circuit is caused by a protrusion 8 protruding upward from the inner lower surface thereof. 7a and a second oil pool portion 7b from which oil flows after lubricating the internal combustion engine 1 through oil circulation in the second oil circuit. As for the oil pan 7, when the oil level of the oil accumulated in the second oil pool portion 7 b rises above the upper end of the projection 8, the oil climbs over the projection 8 and passes through the first oil pool 7 a. It is formed to flow down. The oil pump 6 sucks up the oil accumulated in the first oil reservoir 7a and sends it to the internal combustion engine 1 and the transaxle 2.

  Therefore, the oil circulation in the first oil circuit and the oil circulation in the second oil circuit by driving the oil pump 6 described above are performed in more detail as follows. That is, by driving the oil pump 6, the oil accumulated in the first oil pool portion 7a is sucked up and sent to the transaxle 2 and the internal combustion engine 1, and after lubricating them, the first oil pool portion 7a and the second oil pool respectively. It flows down to the pool part 7b. Further, when the oil level of the oil accumulated in the second oil pool portion 7b rises beyond the upper end of the projection portion 8, the oil passes over the projection portion 8 and flows down to the first oil pool portion 7a. Therefore, the oil circulating in the first oil circuit returns to the first oil pool portion 7a through the first oil pool portion 7a, the oil pump 6, the passage 9, and the transaxle 2. The oil circulating in the second oil circuit returns to the first oil pool portion 7a through the first oil pool portion 7a, the oil pump 6, the passage 10, the internal combustion engine 1, and the second oil pool portion 7b.

Next, the electrical configuration of the oil circulation device in the present embodiment will be described.
The oil circulation device includes an electronic control device 21 that executes various controls such as drive control of the internal combustion engine 1 in a hybrid vehicle, drive control of the motor generators 4 and 5 of the transaxle 2, and control of opening and closing of the control valve 11. .

  The electronic control device 21 includes a CPU that performs various arithmetic processes, a ROM that stores control programs and data, a RAM that temporarily stores CPU calculation results and sensor detection results, and the like. It has input / output ports for inputting / outputting signals. The input port of the electronic control device 21 detects a rotational speed sensor 22 that detects the rotational speed of the internal combustion engine 1, an accelerator position sensor 23 that detects the amount of operation of the accelerator pedal by the driver, and a vehicle speed of the hybrid vehicle. Various sensors such as a vehicle speed sensor 24 are connected.

  The electronic control unit 21 grasps the operating states of the internal combustion engine 1 and the hybrid vehicle based on the detection signals input from the respective sensors, and controls the driving of the internal combustion engine 1 in the hybrid vehicle based on the grasped driving state, the transaxle 2. Various controls such as drive control of the motor generators 4 and 5 and opening / closing control of the control valve 11 are executed.

  FIG. 2 is a flowchart showing a valve control routine for executing the opening / closing control of the control valve 11. This valve control routine is periodically executed through the electronic control device 21 by, for example, a time interruption at predetermined time intervals. In this routine, it is determined whether or not the internal combustion engine 1 is being driven (S101). If the determination is affirmative, the control valve 11 is opened until, for example, a fully open state (S102). If the determination in S101 is negative and it is determined that the internal combustion engine 1 is stopped, the opening of the control valve 11 is set to be smaller than that during the operation of the internal combustion engine 1. A valve closing operation is performed (S103). More specifically, the valve 11 is closed so that the control valve 11 is fully closed.

  In the hybrid vehicle, there is a case where traveling by driving the motor generator 5 is performed while the internal combustion engine 1 is stopped. In this case, heat generation from the transaxle 2 provided with the motor generator 5 increases. At this time, through the opening / closing control of the control valve 11, the opening degree of the valve 11 is set to a value smaller than the value during driving of the internal combustion engine 1 (full open state in this example) (full closed state in this example). The As a result, the flow rate of the oil circulating in the second oil circuit is reduced to “0”, and only the oil is circulated in the first oil circuit, so that the oil is preferentially and effective due to the heat of the transaxle 2. The temperature is increased. More specifically, a large amount of the oil circulates in the second oil circuit and the heat of the oil is suppressed from being taken away by the internal combustion engine 1, whereby the oil is preferentially and effectively caused by the heat of the transaxle 2. The temperature is raised. Furthermore, as described above, the flow rate of the oil in the second oil circuit becomes “0”, which means that the first oil circuit in which the oil circulates does not include the entire oil pan 7 but only the first oil pool portion 7a. It means to become. Therefore, as described above, when the oil is circulated in the first oil circuit, the amount of oil circulated in the first oil circuit can be reduced, and the temperature of the oil can be increased more quickly. become.

  Further, while the internal combustion engine 1 is being driven, the opening degree of the control valve 11 is set to a value (full open state) larger than the value during the stop of the internal combustion engine 1 (fully closed state), and the temperature is raised as described above. In addition, a large amount of oil in the first oil circuit (more precisely, the oil accumulated in the first oil reservoir 7a) flows into the second oil circuit and is sent to the internal combustion engine 1. When this is done, the oil that lubricates the internal combustion engine 1 is efficiently heated, and the heat of the transaxle 2 is efficiently transferred to the oil that lubricates the internal combustion engine 1.

  FIG. 3 shows the first oil pool portion when the internal combustion engine 1 and the transaxle 2 are both started to cool and travel from only driving the motor generator 5 to traveling using the driving of the internal combustion engine 1. It is the time chart which showed the temperature rise aspect of the oil in 7a and the 2nd oil pool part 7b. In the figure, a solid line L1 indicates a change in the temperature of the oil in the first oil reservoir 7a, and a solid line L2 indicates a change in the temperature of the oil in the second oil reservoir 7b.

  As can be seen from the figure, when the vehicle is traveling only by driving the motor generator 5 immediately after the start of traveling (timing T1 to T2), the heat of the motor generator 5 causes the oil in the first oil circuit to rise preferentially and efficiently. Since the temperature rises, the temperature of the oil in the first oil reservoir 7a also rises rapidly as shown by the solid line L1 in FIG. As a result, the viscosity of the oil circulating through the first oil circuit can be quickly reduced to an appropriate value to suitably lubricate the transaxle 2, and the frictional resistance at the transaxle 2 can be reduced.

  Thereafter, when shifting to driving using the drive of the internal combustion engine 1 (T2), more specifically, driving using both the motor generator 5 and the internal combustion engine 1 (T2 to T3), or driving using only the internal combustion engine 1 When the process proceeds to (after T3), a large amount of oil in the first oil circuit that has been heated as described above flows into the second oil circuit. For this reason, the oil circulating through the second oil circuit efficiently rises in temperature, and the temperature of the oil in the second oil pool portion 7b also rises quickly as shown by the solid line L2 in FIG. Then, the oil in the second oil circuit that has been efficiently heated in this manner is sent to the internal combustion engine 1, and the internal combustion engine 1 is lubricated by the oil whose temperature has been increased and the viscosity has decreased to an appropriate value. Is called. Accordingly, it is possible to reduce the rotational resistance of the internal combustion engine 1 due to the oil and to appropriately lubricate the internal combustion engine 1 due to the oil at an early stage after the driving of the internal combustion engine 1 is started. become.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The oil pan 7 shares a part of the first oil circuit that circulates the oil that lubricates the transaxle 2 and the second oil circuit that circulates the oil that lubricates the internal combustion engine 1. Since the common oil is used as the oil circulating through the engine, the heat of the transaxle 2 is efficiently transmitted to the oil that lubricates the internal combustion engine 1. That is, since the heat of the transaxle 2 is directly transmitted to the common oil that lubricates not only the transaxle 2 but also the internal combustion engine 1, the heat of the transaxle 2 is efficiently transferred to the oil that lubricates the internal combustion engine 1. Can communicate. In addition, since it is not necessary to use a heat exchanger or the like when transferring heat from the transaxle 2 to the oil, it is not necessary to provide a new heat exchanger to transfer the heat. In order to realize the transmission, the number of parts is not increased.

  (2) Both the oil circulation in the first oil circuit and the oil circulation in the second oil circuit are performed by a common oil pump 6, and both the internal combustion engine 1 and the transaxle 2 are supplied from the oil pump 6. Oil is sent to. For this reason, the oil circulation in the first oil circuit and the oil circulation in the second oil circuit are separately performed, and the oil is individually sent to the internal combustion engine 1 and the transaxle 2 by these oil pumps. There is no need to provide two such pumps, and the number of oil pumps can be reduced to one to reduce the number of parts.

  (3) When the internal combustion engine 1 and the transaxle 2 start traveling from a cold state and shift from traveling only by driving the motor generator 5 to traveling using the driving of the internal combustion engine 1, the driving of the motor generator 5 is performed. When the vehicle is traveling solely, the temperature of the oil in the first oil circuit can be preferentially and efficiently raised. As a result, the viscosity of the oil in the first oil circuit is quickly reduced to an appropriate value to suitably lubricate the transaxle 2, and the frictional resistance in the transaxle 2 can be reduced. Thereafter, when shifting to driving using the drive of the internal combustion engine 1, a large amount of the oil in the first oil circuit that has been heated as described above flows into the second oil circuit and is sent to the internal combustion engine 1, where the temperature is raised. The internal combustion engine 1 is lubricated by the oil whose viscosity has been reduced to an appropriate value. As a result, the rotational resistance of the internal combustion engine 1 by the oil can be reduced at an early stage after the driving of the internal combustion engine 1 is started, and the internal combustion engine 1 can be appropriately lubricated by the oil. .

  (4) As described above, after the internal combustion engine 1 and the transaxle 2 are both cooled, the vehicle starts traveling from driving only by driving the motor generator 5 to traveling using the driving of the internal combustion engine 1. If the engine 1 generates a large amount of heat due to high-load operation or the like of the internal combustion engine 1, the temperature of the oil may become too high due to the heat. However, the oil that has received the heat of the internal combustion engine 1 as described above flows down into the second oil pool portion 7b, where it mixes with the oil accumulated in the cold state and drops in temperature, and then the first oil pool portion 7a. It starts to flow down. Therefore, after the internal combustion engine 1 and the transaxle 2 start to travel from a cold state and shift from traveling only by driving the motor generator 5 to traveling using the driving of the internal combustion engine 1, the high load of the internal combustion engine 1 is increased. When the heat generation of the engine 1 increases due to operation or the like, it is possible to suppress the temperature of the oil receiving the heat from becoming too high.

  (5) By appropriately changing the oil capacity of the first oil pool portion 7a, the temperature of the oil during circulation of the oil in the first oil circuit can be adjusted to an arbitrary value. Further, by appropriately changing the oil capacity of the second oil pool portion 7b, the temperature of the oil during circulation of the oil in the second oil circuit can be adjusted to an arbitrary value.

In addition, the said embodiment can also be changed as follows, for example.
The oil pump 6 may be an electric type driven by a dedicated motor. In this case, the oil pump 6 is driven during the operation of the internal combustion engine 1 or the traveling of the hybrid vehicle, and is stopped when the internal combustion engine 1 is stopped and the hybrid vehicle is stopped.

  The control valve 11 is not necessarily required to be in the fully closed state while the internal combustion engine 1 is stopped. The opening is smaller than the opening during operation of the internal combustion engine 1 and is more open than the fully closed state. It is sufficient to operate only on the closing side so that

The oil circulation in the first oil passage and the oil circulation in the second oil circuit may be performed by separate oil pumps.
For example, as shown in FIG. 4, the oil circulation in the first oil circuit may be performed by the first oil pump 6a, and the oil circulation in the second oil circuit may be performed by the second oil pump 6b. . In this case, the first oil pump 6a sucks up the oil accumulated in the first oil pool portion 7a of the oil pan 7 and then sends it to the transaxle 2 through the passage 9. The second oil pump 6b After the oil accumulated in 7 a is sucked up, it is sent out to the internal combustion engine 1 through the passage 10. The first oil pump 6a circulates oil in the first oil circuit while the internal combustion engine 1 is being driven or the hybrid vehicle is running, like the oil pump 6 of the above embodiment. The second oil pump 6b is connected to the internal combustion engine 1 and is driven by the rotation of the engine 1 to circulate oil in the second oil circuit.

  According to this configuration, when the first oil pump 6a is driven, the oil accumulated in the first oil pool portion 7a is sucked up and discharged toward the transaxle 2, and after the transaxle 2 is lubricated, the first oil pump 6a is lubricated. It flows down to the oil pool 7a. Further, when the second oil pump 6b is driven, the oil accumulated in the first oil pool portion 7a is sucked up and discharged toward the internal combustion engine 1, and after the engine 1 is lubricated, the oil is stored in the second oil pool portion 7b. It flows down and further passes over the protruding portion 8 and flows down to the first oil pool portion 7a.

  In a hybrid vehicle, when traveling by driving the motor generator 5 is performed while the internal combustion engine 1 is stopped, heat generation from the transaxle 2 provided with the motor generator 5 increases. At this time, the oil discharge amount of the second oil pump 6b driven by the internal combustion engine 1 becomes “0”, which is smaller than that during the drive of the internal combustion engine 1, and the flow rate of oil circulating through the second oil circuit is “ Reduced to "0". As a result, only the oil is circulated in the first oil circuit by driving the first oil pump 6a, and the temperature of the oil is preferentially and effectively raised by the heat of the transaxle 2. Further, since the first oil circuit at this time does not include the entire oil pan 7 but includes only the first oil pool portion 7a, when the oil is circulated in the first oil circuit as described above, the first oil circuit is not included. The amount of oil circulating in the tank can be kept small, and the temperature of the oil can be raised more rapidly.

  Further, during the driving of the internal combustion engine 1, the oil discharge amount of the second oil pump 6b driven by the engine 1 is made larger than the value during the stop of the internal combustion engine 1 (“0”), as described above. The heated oil in the first oil circuit (more precisely, the oil accumulated in the first oil pool portion 7a) flows into the second oil circuit and is sent to the internal combustion engine 1. When this is done, the oil that lubricates the internal combustion engine 1 is efficiently heated, and the heat of the transaxle 2 is efficiently transferred to the oil that lubricates the internal combustion engine 1.

  Therefore, when the internal combustion engine 1 and the transaxle 2 are both cooled, the vehicle starts to travel, and only when the motor generator 5 is driven, the vehicle travels only from driving the motor generator 5 to traveling using the drive of the internal combustion engine 1. During traveling, the temperature of the oil in the first oil circuit can be preferentially and efficiently raised. As a result, the viscosity of the oil in the first oil circuit is quickly reduced to an appropriate value to suitably lubricate the transaxle 2, and the frictional resistance in the transaxle 2 can be reduced. Thereafter, when shifting to driving using the drive of the internal combustion engine 1, a large amount of the oil in the first oil circuit that has been heated as described above flows into the second oil circuit and is sent to the internal combustion engine 1, where the temperature is raised. The internal combustion engine 1 is lubricated by the oil whose viscosity has been reduced to an appropriate value. As a result, the rotational resistance of the internal combustion engine 1 by the oil can be reduced at an early stage after the driving of the internal combustion engine 1 is started, and the internal combustion engine 1 can be appropriately lubricated by the oil. .

  In this example, the first oil pump 6a may be an electric type driven by a dedicated motor. In this case, the first oil pump 6a is driven while the internal combustion engine 1 is operating or while the hybrid vehicle is running, and is stopped when the internal combustion engine 1 is stopped and the hybrid vehicle is stopped. The second oil pump 6b may also be an electric type driven by a dedicated motor. In this case, the second oil pump 6b is driven while the internal combustion engine 1 is operating, and is stopped when the engine 1 is stopped. However, the driving of the second oil pump 6b is not necessarily stopped as described above while the internal combustion engine 1 is stopped, and the oil discharge amount from the pump 6 is larger than that during the operation of the internal combustion engine 1. The oil discharge amount may be simply reduced so as to be a small value and a value larger than “0”.

  It is not always necessary to partition the inside of the oil pan 7 into the first oil pool portion 7a and the second oil pool portion 7b.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Transaxle, 3 ... Gear mechanism, 4 ... Motor generator, 5 ... Motor generator, 6 ... Oil pump, 6a ... 1st oil pump, 6b ... 2nd oil pump, 7 ... Oil pan, 7a DESCRIPTION OF SYMBOLS 1st oil pool part, 7b ... 2nd oil pool part, 8 ... Projection part, 9 ... Passage, 10 ... Passage, 11 ... Control valve, 21 ... Electronic control unit (valve control means), 22 ... Rotation speed sensor, 23 ... Accelerator position sensor, 24 ... Vehicle speed sensor.

Claims (3)

An oil circulation device for a hybrid vehicle in which an internal combustion engine and a motor provided in a transaxle are mounted as a prime mover,
A first oil circuit for circulating oil for lubricating the transaxle;
A second oil circuit for circulating oil for lubricating the internal combustion engine;
With
A part of the first oil circuit and the second oil circuit are shared, and a common oil is used as oil circulating in the oil circuit ,
The circulation of oil in the first oil circuit and the circulation of oil in the second oil circuit are performed by at least one oil pump,
The oil after lubricating the transaxle through the circulation of oil in the first oil circuit and the oil after lubricating the internal combustion engine through the circulation of oil in the second oil circuit are respectively common oil pans. Flowed down to
The inside of the oil pan includes a first oil pool where oil after lubricating the transaxle through oil circulation in the first oil circuit, and the internal combustion engine through oil circulation in the second oil circuit. The oil after the oil has been lubricated is partitioned into a second oil pool part, and the oil can flow down to the first oil pool part by rising the oil level of the oil accumulated in the second oil pool part. And
The oil circulating apparatus for a hybrid vehicle , wherein the oil pump sucks up oil accumulated in the first oil pool and sends it to the internal combustion engine and the transaxle . The oil circulation device for a hybrid vehicle according to claim 1 ,
A single oil pump that performs both the circulation of oil in the first oil circuit and the circulation of oil in the second oil circuit;
A control valve which is provided between the oil pump and the internal combustion engine in the second oil circuit and which opens and closes to adjust the flow rate of oil sent from the oil pump to the internal combustion engine;
Valve control means for controlling the drive of the control valve so that the opening of the control valve is smaller than when the internal combustion engine is stopped when the engine is being driven;
Oil circulation system for a hybrid vehicle, characterized by Ru further comprising a. The oil circulation device for a hybrid vehicle according to claim 1,
A first oil pump for circulating oil in the first oil circuit during driving of the internal combustion engine or traveling of a hybrid vehicle;
A second oil pump connected to the internal combustion engine and driven by rotation of the engine to circulate oil in the second oil circuit;
Equipped with a,
The first oil pump circulates oil in the first oil circuit by sucking up the oil accumulated in the first oil pool and sending it to the transaxle,
The second oil pump circulates oil in the second oil circuit by sucking up the oil accumulated in the first oil pool and sending it out to the internal combustion engine. apparatus.

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