JP5876290B2 - Vehicle control system - Google Patents

Description

  The present invention relates to a vehicle control system, and more particularly to a vehicle control system for a vehicle that uses an electric oil pump for cooling a rotating electrical machine.

  In a vehicle equipped with a rotating electrical machine, an oil pump for circulating a refrigerant that cools the rotating electrical machine is used. In a vehicle in which an engine is mounted together with a rotating electrical machine, a mechanical oil pump connected to the output rotation shaft of the engine can be used. When the engine stops, this mechanical oil pump also stops operating. Therefore, an electric oil pump that is driven independently of the operation of the engine is used so that the rotating electrical machine can be cooled while the engine is stopped.

  For example, in Patent Document 1, in a vehicle control device, when a discharge amount of a mechanical oil pump driven by an engine at the time of fuel cut is insufficient, an oil pump driven by a motor generator or an electric oil pump is driven. It is stated that

  Patent Document 2 describes that, for an oil pump unit including a mechanical oil pump and an electric oil pump, the total required oil supply amount is calculated based on the vehicle speed and the required torque. Furthermore, since the leak amount increases as the oil temperature and hydraulic pressure of the mechanical oil pump increases, it is stated that the discharge amount of the electric oil pump is calculated by correcting the leak amount.

Japanese Patent Laid-Open No. 2004-256063 JP 2009-96326 A

  Although the mechanical oil pump is driven by the engine, the energy required for driving the mechanical oil pump is not so large when viewed from the overall driving force of the engine. Therefore, driving the mechanical oil pump greatly reduces the fuel consumption of the entire vehicle. Absent. On the other hand, driving the electric oil pump consumes electric power, leading to a reduction in fuel consumption of the entire vehicle. Therefore, it is necessary to appropriately switch the operation between the electric oil pump and the mechanical oil pump in consideration of the fuel consumption of the entire vehicle.

  Further, when the electric oil pump and the mechanical oil pump are connected in parallel, it is necessary to prevent the back flow of oil when switching the operation of the electric pump and the mechanical oil pump.

  An object of the present invention is to provide a vehicle control system that can appropriately switch the operation of an electric oil pump and a mechanical oil pump in consideration of fuel consumption of the entire vehicle. Another object of the present invention is to provide a vehicle control system capable of performing control so that backflow of oil does not occur when switching between operation of an electric pump and a mechanical oil pump. The following means contribute to at least one of the above objects.

A vehicle control system according to the present invention is a power unit that includes an internal combustion engine and a rotating electrical machine, and a pump unit that circulates a refrigerant that cools the rotating electrical machine, and includes an electric oil pump and mechanical oil driven by the internal combustion engine. An oil pump unit configured by connecting the pumps in parallel with each other, and when the operation mode of the power unit is an EV operation mode in which the rotating electrical machine is operated without operating the internal combustion engine, the electric oil pump is operated, A control device that operates a mechanical oil pump in the HV operation mode in which both rotating electrical machines can be operated, and the control device does not overlap the operation state of the electric oil pump and the operation state of the mechanical oil pump As described above, after stopping the operation of one of the electric oil pump and the mechanical oil pump, the other side Characterized Rukoto to the operation start.

  Further, in the vehicle control system according to the present invention, when the operation mode of the power unit is the EV operation mode, the control device has a condition that the temperature of the rotating electrical machine is equal to or higher than a predetermined threshold temperature and an output of the rotating electrical machine is previously set. It is preferable to start the electric oil pump based on a condition that is equal to or higher than a predetermined threshold output.

  With the above configuration, the vehicle control system includes a power unit including an internal combustion engine and a rotating electrical machine, and an oil pump unit configured by connecting an electric oil pump and a mechanical oil pump in parallel to each other. When the operation mode of the power plant is the EV operation mode in which the rotating electric machine is operated without operating the internal combustion engine, the electric oil pump is operated, and in the HV operation mode in which both the internal combustion engine and the rotating electric machine are operable. Operate the mechanical oil pump. As described above, since the electric oil pump is operated only when the internal combustion engine is not operated, it is possible to suppress a reduction in fuel consumption caused by operating the electric oil pump.

  In the vehicle control system, when the operation mode of the power plant is the EV operation mode, a condition that the temperature of the rotating electrical machine is equal to or higher than a predetermined threshold temperature, and a condition that the output of the rotating electrical machine is equal to or higher than a predetermined threshold output Based on the above, the electric oil pump is started. Accordingly, the operating condition of the electric oil pump can be selected according to whether the user is preferentially requesting the vehicle to improve fuel efficiency or preferentially requesting output improvement.

  For example, when the electric oil pump is operated when the temperature of the rotating electrical machine is equal to or higher than a predetermined threshold temperature and the output of the rotating electrical machine is equal to or higher than the predetermined threshold output, Compared to the above or when the electric oil pump is operated when the output of the rotating electrical machine is equal to or higher than a predetermined threshold output, the former has a narrower operating range as a vehicle. Therefore, since the former requires less time for operating the electric oil pump than the latter, it is better to operate the electric oil pump under the former conditions when priority is given to improving fuel efficiency. Compared to the former, the latter takes longer operation time of the electric oil pump and sacrifices fuel efficiency.However, since it takes longer time to output power, when the priority is given to improving the output, the electric oil pump is operated under the latter condition. It is good to operate.

  Also, in the vehicle control system, a predetermined standby time from the stoppage of operation of either the electric oil pump or the mechanical oil pump so that the operation state of the electric oil pump and the operation state of the mechanical oil pump do not overlap. Then, the operation on the other side is started. By setting the standby time to a time when oil backflow due to operation switching does not occur, when the electric oil pump and mechanical oil pump are connected in parallel, the oil is switched when the operation of the electric pump and mechanical oil pump is switched. The reverse flow does not occur.

1 is a configuration diagram of a vehicle control system according to an embodiment of the present invention. 5 is a flowchart showing a procedure for selectively using a mechanical oil pump and an electric oil pump in an embodiment according to the present invention. It is a flowchart which shows the procedure which changes the operating condition of an electric oil pump according to a user's request | requirement in EV operation mode of embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a flowchart which shows the procedure which prevents the backflow of the lubricating oil which is a refrigerant | coolant. In FIG. 4, it is a figure explaining the setting of the standby time when switching from a mechanical oil pump to an electric oil pump. In FIG. 4, it is a figure explaining the setting of the waiting time when switching from an electric oil pump to a mechanical oil pump.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following, a configuration having an engine, one rotating electrical machine, and a power transmission mechanism provided therebetween as a power unit will be described, but this is an illustrative example. Here, it is sufficient if it has an engine and a rotating electrical machine, and the relationship between the output of the engine and the output of the rotating electrical machine can be appropriately changed according to the specifications of the vehicle. Moreover, although the description will be given assuming that the rotating electrical machine mounted on the vehicle is one, this is also an example, and a plurality of rotating electrical machines may be mounted on the vehicle. For example, one rotating electric machine may be used for driving, and the other rotating electric machine may be used for power generation, or separate rotating electric machines may be used for front wheel driving and rear wheel driving.

  In addition, the power supply device connected to the rotating electrical machine will be described as including a power storage device, a voltage converter, a smoothing capacitor, and an inverter, but this is a description of the main components and includes other components It is good. For example, a low voltage inverter circuit, a system main relay, a DC / DC converter, and the like may be included. The power supply for the drive circuit of the electric oil pump will be described as a low voltage power supply independent of the power supply device for the rotating electrical machine, but this is an illustrative example. For example, electric power converted into a low voltage from a power supply device of a rotating electrical machine may be supplied to a drive circuit of an electric oil pump.

  In the following description, it is assumed that the rotating electrical machine and the power transmission mechanism are housed in one case body, and the refrigerant circulates between the case and the oil pump unit. However, this is an illustrative example. is there. For example, it is good also as a structure which a refrigerant | coolant circulates between a rotary electric machine, a power transmission mechanism, and an oil pump unit, without putting together in one case.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing a configuration of a vehicle control system 10 for a hybrid vehicle. The vehicle control system 10 is a system that appropriately controls the operation of the engine 14 and the rotating electrical machine 18 constituting the power unit 12 and the drive of the oil pump unit 40 for cooling the rotating electrical machine 18.

  The vehicle control system 10 includes an engine 14 and a rotating electrical machine 18 as a power device 12 that is a drive source of a hybrid vehicle, and a power storage device 32, a voltage converter 34, and an inverter 36 as a power supply device 30 connected to the rotating electrical machine 18. And smoothing capacitors 37 and 38. The vehicle control system 10 further includes an oil pump unit 40 that circulates and supplies the refrigerant 50 into the case body 22 that includes the rotating electrical machine 18 therein. The oil pump unit 40 includes a mechanical oil pump 42 driven by the engine 14 and an electric oil pump 44 driven by an EOP drive circuit 62 operated by a low voltage power supply 64. And the vehicle control system 10 is comprised including the control apparatus 70 which controls these operation | movement as a whole.

  The power unit 12 includes an engine 14, a rotating electrical machine 18, and a power transmission mechanism 16 provided therebetween. The engine 14 is an internal combustion engine. The rotating electrical machine 18 is a motor / generator (M / G) mounted on the hybrid vehicle, and functions as a motor when electric power is supplied from a power supply device 30 including the inverter 36 as a drive circuit. This is a three-phase synchronous rotating electric machine that functions as a generator when driven by a vehicle or when braking a hybrid vehicle.

The temperature detector 24 provided in the rotating electrical machine 18 is rotating electrical machine temperature detection means for detecting the temperature θ _M of the rotating electrical machine 18. The detection data of the temperature detector 24 is transmitted to the control device 70 using an appropriate signal line.

  The power transmission mechanism 16 is a mechanism having a function of distributing the power supplied to the hybrid vehicle between the output of the engine 14 and the output of the rotating electrical machine 18. As the power transmission mechanism 16, a planetary gear mechanism connected to three shafts, that is, an output shaft of the engine 14, an output shaft of the rotating electrical machine 18, and an output shaft to an axle (not shown) can be used. In FIG. 1, the shaft connecting the power transmission mechanism 16 and the engine 14 is the output shaft 20 of the engine 14. The output shaft 20 is connected to the drive shaft of the mechanical oil pump 42 via the connection shaft 60 and is used to drive the mechanical oil pump 42.

  The power supply device 30 is a device for driving the rotary electric machine 18. The power storage device 32 constituting the power supply device 30 is a chargeable / dischargeable high voltage secondary battery. Specifically, it is a lithium ion assembled battery having a terminal voltage of about 200V to about 300V. The assembled battery is obtained by combining a plurality of batteries each having a terminal voltage of 1 V to several V, called a single battery or a battery cell, to obtain the predetermined terminal voltage. As the power storage device 32, a nickel-metal hydride battery, a large capacity capacitor, or the like can be used.

  The voltage converter 34 is a circuit that is disposed between the power storage device 32 and the inverter 36 and has a DC voltage conversion function. The voltage converter 34 includes a reactor and a switching element. As a voltage conversion function, the voltage on the power storage device 32 side is boosted using the reactor energy storage action and supplied to the inverter 36 side, and the electric power from the inverter 36 side is stepped down to the power storage device 32 side for charging. And a step-down function for supplying electric power.

  The inverter 36 is a drive circuit connected to the rotating electrical machine 18 and includes a plurality of switching elements, reverse connection diodes, and the like, and has a function of performing power conversion between AC power and DC power. That is, the inverter 36 has an AC / DC conversion function that converts the AC three-phase regenerative power from the rotating electrical machine 18 into DC power and supplies it as a charging current to the power storage device 32 when the rotating electrical machine 18 functions as a generator. . Further, when the rotary electric machine 18 functions as a motor, it has a quadrature conversion function that converts DC power from the power storage device 32 side into AC three-phase drive power and supplies it to the rotary electric machine 18 as AC drive power.

  The inverter 36 is a circuit that generates a three-phase drive signal by PWM (Pulse Wide Modulation) control that appropriately adjusts on / off timings of a plurality of switching elements and supplies the three-phase drive signal to the rotating electrical machine 18. PWM (Pulse Width Modulation) control is control for modulating the pulse width by comparing a fundamental wave signal having a period corresponding to the rotation period of the rotating electrical machine 18 and a carrier signal having a sawtooth waveform. The frequency of the carrier signal is called a carrier frequency, but the carrier frequency is set according to the frequency of the fundamental wave in order to ensure the controllability of the PWM control. For example, when the rotational speed of the rotating electrical machine 18 increases, the frequency of the fundamental wave increases, so a high carrier frequency is set. Conversely, when the rotational speed of the rotating electrical machine 18 decreases, the frequency of the fundamental wave decreases, so a low carrier cycle is set.

  The smoothing capacitor 37 provided between the power storage device 32 and the voltage converter 34 is a capacitor element having a function of smoothing the voltage and current on the power storage device 32 side. The smoothing capacitor 38 provided between the voltage converter 34 and the inverter 36 is a capacitor element having a function of smoothing the voltage and current on the inverter 36 side.

  The case body 22 is a housing that includes the power transmission mechanism 16 and the rotating electrical machine 18 inside. The internal space of the case body 22 stores a coolant 50 for lubricating the movable parts of the power transmission mechanism 16 and the rotating electrical machine 18 and cooling the power transmission mechanism 16 and the rotating electrical machine 18. As the refrigerant, a lubricating oil called ATF can be used.

  The oil pump unit 40 is a unit including a mechanical oil pump 42 and an electric oil pump 44, and has a function of circulating and supplying the refrigerant 50 to the internal space of the case body 22. The refrigerant discharge path 52 is a refrigerant distribution pipe that connects the oil pump unit 40 and a refrigerant discharge port provided on the lower side of the case body 22 along the direction of gravity, that is, at a location near the bottom of the case body 22. The refrigerant supply path 54 is a refrigerant distribution pipe that connects the oil pump unit 40 and a refrigerant supply port provided on the upper side of the case body 22 along the direction of gravity, that is, at a location near the ceiling of the case body 22.

  A mechanical oil pump 42 shown as MOP in FIG. 1 is a pump whose drive shaft is connected to the output shaft 20 of the engine 14 via a connection shaft 60, and is driven when the engine 14 operates. That is, driving of the mechanical oil pump 42 is started with the start of the engine 14, and driving of the mechanical oil pump 42 is ended when the engine 14 is stopped.

  The electric oil pump 44 shown as EOP in FIG. 1 is driven by the EOP drive circuit 62 under a control signal from the control device 70. The EOP drive circuit 62 is supplied with DC power from a low voltage power supply 64. The low voltage means a low voltage compared to the voltage of the power storage device 32, and for example, a voltage of about 12V to 16V can be used. As a motor for rotating the drive shaft of the electric oil pump 44, a three-phase synchronous motor can be used. In this case, the EOP drive circuit 62 includes an inverter having a DC / AC conversion function. A single-phase AC motor can be used instead of the three-phase synchronous motor, or a DC motor can be used. The content of the EOP drive circuit 62 is changed according to the motor type used as a motor for rotating the drive shaft of the electric oil pump 44.

  The mechanical oil pump 42 and the electric oil pump 44 are connected in parallel with each other between the refrigerant discharge path 52 and the refrigerant supply path 54. The check valve 46 is a valve provided so that the refrigerant 50 does not flow back between the mechanical oil pump 42 and the refrigerant supply port of the case body 22. Similarly, the check valve 48 is a valve provided so that the refrigerant 50 does not flow backward between the electric oil pump 44 and the refrigerant supply port of the case body 22.

  As described above, the check valves 46 and 48 are provided. However, if the mechanical oil pump 42 and the electric oil pump 44 are simultaneously driven, a problem arises. That is, when the mechanical oil pump 42 is driven, the check valve 46 is open because the pressure on the mechanical oil pump 42 side is higher than the pressure at the refrigerant supply port of the case body 22. . Similarly, when the electric oil pump 44 is driven, the check valve 48 is open because the pressure on the electric oil pump 44 side is higher than the pressure at the refrigerant supply port of the case body 22.

  Thus, when the mechanical oil pump 42 and the electric oil pump 44 are driven simultaneously, the check valve 46 and the check valve 48 are both open. Therefore, the mechanical oil pump 42 and the electric oil pump 44 are in communication with each other, and the refrigerant 50 does not circulate between the oil pump unit 40 and the internal space of the case body 22, Circulation with the electric oil pump 44 may occur. As a result, the cooling function of the oil pump unit 40 is reduced with respect to the power transmission mechanism 16 and the rotating electrical machine 18 inside the case body 22. This is the problem to be solved by the present invention.

  The control device 70 is a control circuit having a function of controlling each of the above-described elements as a whole. In particular, here, the control device 70 has a function of performing a control for appropriately switching the operation between the mechanical oil pump 42 and the electric oil pump 44. . Such a control device 70 can be configured by a computer suitable for mounting on a vehicle.

The control device 70 includes a power device operation mode determination unit 72 that determines whether the operation mode of the power device is an EV operation mode or an HV operation mode, and a rotating electrical machine that determines whether or not the temperature θ _M of the rotating electrical machine 18 is equal to or higher than a threshold temperature. A temperature determination unit 74, a rotary electric machine output determination unit 76 that determines whether the output of the rotary electric machine 18 is equal to or higher than a threshold output, an EOP operation control unit 78 that controls the operation of the electric oil pump 44, and a mechanical oil pump 42. And an oil pump switching control unit 80 that controls switching of operations between the electric oil pump 44 and the electric oil pump 44. These functions can be realized by executing software. Specifically, it can be realized by executing an oil pump switching control program.

  FIG. 2 is a flowchart showing a procedure for properly using the mechanical oil pump and the electric oil pump in consideration of the overall fuel consumption of the hybrid vehicle. Each procedure corresponds to each processing procedure of the oil pump switching control program. First, it is determined whether or not the engine 14 is operating (S10). This determination can be made based on the presence / absence of a rotation signal of the engine 14 or the contents of a command signal from the control device 70 to the engine 14.

  The determination in S10 is affirmative when the engine 14 is operating, for example, in the HV operation mode in which both the engine 14 and the rotating electrical machine 18 can be operated. At this time, since the mechanical oil pump 42 is driven by the operating engine 14 (S12), the electric oil pump 44 is not driven.

  On the other hand, when the determination in S10 is negative, since the engine 14 is not operating, for example, the EV operation mode in which the rotating electrical machine 18 is operated without operating the engine 14. At this time, since the mechanical oil pump 42 cannot be driven by the engine 14, the electric oil pump 44 is driven (S14).

  As described above, by operating the electric oil pump 44 only when the engine 14 is not operated, it is possible to suppress a reduction in fuel consumption caused by operating the electric oil pump 44.

  FIG. 3 is a diagram showing a procedure for changing the operating condition of the electric oil pump 44 in response to a user request for the vehicle when the operating mode of the power unit 12 is the EV operating mode. Each procedure corresponds to each processing procedure of the oil pump switching control program.

  Here, first, it is confirmed that the operation mode of the power unit 12 is the EV operation mode (S20), and then, it is confirmed that the electric oil pump 44 is stopped (S22). And the request | requirement with respect to a user's vehicle is acquired (S24). Here, the user's request for a vehicle is divided into a fuel efficiency priority request for extending the travel distance as much as possible and an output priority request for a powerful travel at the expense of fuel efficiency. The distinction between the two requests can be obtained by, for example, the degree of accelerator depression by the user, and when the hybrid vehicle is provided with an eco switch, the eco switch is turned on / off.

When the user request is an output priority request (S26), it is determined whether or not the temperature θ _M of the rotating electrical machine 18 is equal to or higher than a predetermined threshold temperature θ _M0 . If the determination in S26 is affirmative, the electric oil pump 44 is driven as it is (S38). If the determination in S26 is affirmative, it is next determined whether or not the output T _M of the rotating electrical machine 18 is _{equal to} or greater than a predetermined threshold output T _M0 (S30). If the determination in S30 is affirmative, the electric oil pump 44 is driven as it is (S38).

That is, in the case of the output priority request, the electric oil pump 44 is operated when the temperature θ _M of the rotating electrical machine 18 is equal to or higher than the threshold temperature θ _M0 or the output T _M of the rotating electrical machine 18 is equal to or higher than the threshold output T _M0 . . Here, the operating condition of the electric oil pump 44 is OR (the temperature θ _M of the rotating electrical machine 18 is not less than the threshold temperature θ _M0 ) OR (the output T _M of the rotating electrical machine 18 is not less than the threshold output T _M0 ).

On the other hand, when the user request is a distance priority request (S32), it is determined whether or not the temperature θ _M of the rotating electrical machine 18 is equal to or higher than a predetermined threshold temperature θ _M0 . If the determination in S26 is affirmative, it is next determined whether or not the output T _M of the rotating electrical machine 18 is _{equal to} or greater than a predetermined threshold output T _M0 (S36). If the determination in S36 is affirmative, the electric oil pump 44 is driven for the first time (S38).

That is, when the distance priority request is made, the electric oil pump 44 is operated when the temperature θ _M of the rotating electrical machine 18 is equal to or higher than the threshold temperature θ _M0 and the output T _M of the rotating electrical machine 18 is equal to or higher than the threshold output T _M0 . . Here, the operating condition of the electric oil pump 44 is AND (the temperature θ _M of the rotating electrical machine 18 is not less than the threshold temperature θ _M0 ) and AND (the output T _M of the rotating electrical machine 18 is not less than the threshold output T _M0 ).

In general, the AND region of two events is narrower than the OR region of the same two events. Therefore, considering the range in which the electric oil pump 44 is driven in the traveling state of the hybrid vehicle (the temperature θ _M of the rotating electrical machine 18 is equal to or higher than the threshold temperature θ _M0 ) AND (the output T _{M of the} rotating electrical machine 18 is the threshold output T _M0 The above range is narrower than the range of OR (the output T _M of the rotating electrical machine 18 is greater than or equal to the threshold output T _M0 ) (the temperature θ _M of the rotating electrical machine 18 is greater than or equal to the threshold temperature θ _M0 ).

Therefore, the range in which the electric oil pump 44 operates is narrower in the range of (the temperature θ _M of the rotating electrical machine 18 is equal to or higher than the threshold temperature θ _M0 ) and AND (the output T _M of the rotating electrical machine 18 is equal to or higher than the threshold output T _M0 ). That is, it is a range suitable for a fuel efficiency improvement request or a distance priority request.

Conversely, the range in which the electric oil pump 44 operates is wider in the range of OR (the temperature θ _M of the rotating electrical machine 18 is the threshold temperature θ _M0 or more) OR (the output T _M of the rotating electrical machine 18 is the threshold output T _M0 or more). Therefore, the fuel consumption is sacrificed, but the power can be secured in a wide range, and the range is suitable for the output priority request.

Thus, based on the condition that the temperature θ _M of the rotating electrical machine 18 is equal to or higher than the predetermined threshold temperature θ _M0 and the condition that the output T _M of the rotating electrical machine 18 is equal to or higher than the predetermined threshold output T _M0. By starting the oil pump 44, it is possible to appropriately respond to the user's request.

  FIG. 4 shows that the lubricating oil as the refrigerant 50 is prevented from flowing back when the operation mode of the power unit of the hybrid vehicle or the operation of the mechanical oil pump 42 and the operation of the electric oil pump 44 are switched according to the user's request. It is a flowchart which shows a procedure. Each procedure corresponds to each processing procedure of the oil pump switching control program. Here, the operation switching means that one side of the mechanical oil pump 42 or the electric oil pump 44 is operating, and then the operation on the one side is stopped and the other side is operated.

  Here, first, it is determined whether the mechanical oil pump 42 is operating or the electric oil pump 44 is operating in the oil pump unit 40 (S40). This determination is based on detection of the rotational speed of the mechanical oil pump 42 and detection of the rotational speed of the electric oil pump 44 when the mechanical oil pump 42 and the electric oil pump 44 are provided with a rotational speed detection means. Can be done. It can also be determined from the content of the command signal from the control device 70 to the EOP drive circuit 62, the content of the command signal to the engine 14, and the like.

  In order to stop the operation of the mechanical oil pump 42 and operate the electric oil pump 44 when the mechanical oil pump 42 is operating (S42), first, an operation stop command is output to the mechanical oil pump 42. (S44). Since the mechanical oil pump 42 does not stop alone, an operation stop command is actually output from the control device 70 to the engine 14.

  Then, it is determined whether or not the mechanical oil pump 42 has actually stopped (S46). This determination can be made based on detection of the rotational speed of the mechanical oil pump 42 when the mechanical oil pump 42 is provided with a rotational speed detection means. Further, when a hydraulic pressure detection means is provided in the refrigerant supply path 54, it can be performed based on the hydraulic pressure of the refrigerant supply path 54.

If the determination in S46 is affirmative, it is determined whether or not a predetermined standby time t _A has elapsed since that time (S48). The standby time t _A is set to an allowance time that prevents the refrigerant 50 discharged by the electric oil pump 44 from flowing back to the mechanical oil pump 42 when the electric oil pump 44 is operated next time. The reverse flow occurs when the check valve 46 is still open when the check valve 48 is opened by the operation of the electric oil pump 44. Therefore, the standby time t _A is set longer than the time required for the operation of the mechanical oil pump 42 to stop and the check valve 46 to close.

Then, after the standby time t _{A has} elapsed, the electric oil pump 44 is driven (S50). Thus, the refrigerant 50 from the electric oil pump 44 to the mechanical oil pump 42 is set by setting the waiting time t _A between the mechanical oil pump 42 actually stopping operation and the driving of the electric oil pump 44. Can be prevented. And the cooling function fall of the mechanical oil pump 42 which may arise by the backflow of the refrigerant | coolant 50 can be suppressed.

FIG. 5 is a diagram for explaining how the standby time t _A is set. The horizontal axis indicates time, and the vertical axis indicates whether the mechanical oil pump 42 or the electric oil pump 44 is operating or stopped. Here, initially, the mechanical oil pump 42 is in an operating state, and the time t ₁ is when a stop command is output to the mechanical oil pump 42 and at the timing of S44 in FIG. Then, the time t ₂ is in fact when the mechanical oil pump 42 is stopped, it is the timing S46 is affirmative in FIG. Time t ₃ is the timing when the determination in S48 of FIG. 4 is affirmed when the standby time t _{A has} elapsed from time t ₂ . At time t ₃ , a drive command is output from the control device 70 to the EOP drive circuit 62, and the electric oil pump 44 is driven.

  Returning to FIG. 4, when the electric oil pump 44 is in operation (S52), in order to stop the operation of the electric oil pump 44 and operate the mechanical oil pump 42, first, an operation stop command is sent to the electric oil pump 44. Is output (S54). Specifically, an operation stop command is output from the control device 70 to the EOP drive circuit 62.

  Then, it is determined whether or not the electric oil pump 44 has actually stopped (S56). This determination can be made based on the detection of the rotational speed of the electric oil pump 44 when the electric oil pump 44 is provided with a rotational speed detection means. Further, when a hydraulic pressure detection means is provided in the refrigerant supply path 54, it can be performed based on the hydraulic pressure of the refrigerant supply path 54.

If the determination in S56 is affirmative, it is determined whether or not a predetermined standby time t _B has elapsed since that time (S58). The standby time t _B is set to an allowance time that prevents the refrigerant 50 discharged by the mechanical oil pump 42 from flowing back to the electric oil pump 44 when the mechanical oil pump 42 is operated next time. Backflow occurs when check valve 46 is still open when check valve 46 is opened by operation of mechanical oil pump 42. Therefore, the standby time t _B is set longer than the time required for the operation of the electric oil pump 44 to stop and the check valve 48 to close.

Then, after the standby time t _{B has} elapsed, the mechanical oil pump 42 is driven (S60). In this way, the refrigerant 50 from the mechanical oil pump 42 to the electric oil pump 44 is set by setting the standby time t _B between the time when the electric oil pump 44 actually stops operating and the time when the mechanical oil pump 42 is driven. Can be prevented. And the fall of the cooling function of the electric oil pump 44 which can arise by the backflow of the refrigerant | coolant 50 can be suppressed.

FIG. 6 is a diagram for explaining how the standby time t _B is set. The horizontal axis indicates time, and the vertical axis indicates whether the electric oil pump 44 or the mechanical oil pump 42 is operating or stopped. Here, first in the operating state the electric oil pump 44, the time t ₄ of when the stop command to the electric oil pump 44 is output, is when the timing of S54 of FIG. Then, the time t _5, in fact when the electric oil pump 44 is stopped, it is the timing S56 is affirmative in FIG. Time t ₆ is the timing when the determination in S58 of FIG. 4 is affirmed when the standby time t _{B has} elapsed from time t ₅ . At this time t ₆ , a drive command is output from the control device 70 to the engine 14, the engine 14 is started, and the mechanical oil pump 42 is driven.

  The vehicle control system according to the present invention can be used for a vehicle equipped with a mechanical oil pump and an electric oil pump.

  DESCRIPTION OF SYMBOLS 10 Vehicle control system, 12 Power unit, 14 Engine, 16 Power transmission mechanism, 18 Rotating electric machine, 20 Output shaft, 22 Case body, 24 Temperature detector, 30 Power supply device, 32 Power storage device, 34 Voltage converter, 36 Inverter, 37, 38 Smooth condenser, 40 Oil pump unit, 42 Mechanical oil pump, 44 Electric oil pump, 46, 48 Check valve, 50 Refrigerant, 52 Refrigerant discharge path, 54 Refrigerant supply path, 60 Connection shaft, 62 EOP drive circuit , 64 low voltage power supply, 70 controller, 72 power unit operation mode determination unit, 74 rotating electrical machine temperature determination unit, 76 rotating electrical machine output determination unit, 78 EOP operation control unit, 80 oil pump switching control unit.

Claims (1)

A power unit including an internal combustion engine and a rotating electric machine;
An oil pump unit configured to circulate a refrigerant that cools the rotating electrical machine, and includes an electric oil pump and a mechanical oil pump driven by an internal combustion engine connected in parallel;
When the operation mode of the power unit is the EV operation mode in which the rotating electric machine is operated without operating the internal combustion engine, the electric oil pump is operated, and in the HV operation mode in which both the internal combustion engine and the rotating electric machine are operable, the machine A control device for operating the oil pump;
Equipped with a,
The control device
In order not to overlap the operation state of the electric oil pump and the operation state of the mechanical oil pump, after the operation stop on one side of the electric oil pump or the mechanical oil pump, after a predetermined waiting time, vehicle control system according to claim Rukoto to the operation start.

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