JP2013193511A - Vehicle control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly cope with a temperature of a refrigerant when a rotary electric machine is cooled by an electric refrigerant pump in a vehicle control system.SOLUTION: A vehicle control system 10 includes a cooling mechanism 12, which has a rotary electric machine 20 and an electric oil pump 44 on a hybrid vehicle, and a controller 80. The controller 80 includes an EOP duty changing section 82 which changes an on/off duty of the electric oil pump 44 to control the electric oil pump 44 in consideration of changes at a temperature θC of a refrigerant 26, an EOP discharge characteristic control section 84 which performs control to maintain a flow rate or a discharge pressure of the electric oil pump 44 at a constant level, and further includes a rotary electric machine torque determination section 86 which determines whether or not a torque of the rotary electric machine 20 is not less than a predetermined threshold torque when implementing control for making a load of the electric oil pump 44 appropriate.

Description

  The present invention relates to a vehicle control system, and more particularly to a vehicle control system capable of cooling a rotating electrical machine with an electric refrigerant pump.

  Vehicles equipped with an engine and a rotating electrical machine are driven by a battery, etc., even when the engine is stopped, in addition to a mechanical oil pump driven by the engine in order to cool the rotating electrical machine, automatic transmission, etc. An oil pump called an electric type or an electric type is used.

  For example, Patent Document 1 describes a control device that supplies hydraulic pressure to a hydraulic mechanism by controlling either a mechanical oil pump driven by an engine or an electric oil pump driven by a battery. Here, it is disclosed that the degree of deterioration is determined based on the difference between the target discharge amount and the actual discharge amount of each oil pump, and the drive time ratio of each oil pump is changed according to the difference.

  In Patent Document 2, when an electric oil pump is provided together with a mechanical oil pump directly connected to an engine crankshaft, deterioration of the electric oil pump is not possible for operating for a long time. It has been pointed out that it is accelerated. Here, the operation time of the electric oil pump is obtained based on detection signals of the engine speed sensor and the vehicle speed sensor, and when the operation time exceeds a predetermined allowable operation time, the engine is started and the mechanical oil pump is used. Supplying hydraulic pressure is disclosed.

JP 2009-228754 A JP 2002-155865 A

  By the way, the temperature of the refrigerant rises by continuing the operation of the electric oil pump. When the temperature of the refrigerant is low, the viscosity of the refrigerant is high, and when the temperature of the refrigerant is high, the viscosity of the refrigerant is low. In such a case, if the driving condition of the electric oil pump is constant regardless of the refrigerant temperature, the refrigerant may not be discharged sufficiently than desired when the temperature is low, and cooling may be insufficient. In other words, power is wasted. As described above, it is necessary to consider the temperature of the refrigerant in the operation control of the electric oil pump.

  In addition, the electric oil pump deteriorates as the accumulated operation time becomes longer, and a failure is likely to occur. Therefore, it is necessary to consider an appropriate operation time for the operation control of the electric oil pump.

  Thus, in the operation control of the electric oil pump, appropriate consideration is necessary for the temperature of the refrigerant and the suppression of deterioration and failure of the electric oil pump.

  An object of the present invention is to provide a vehicle control system that can appropriately cope with the temperature of a refrigerant when a rotating electrical machine is cooled by an electric refrigerant pump. Another object is to provide a vehicle control system that can appropriately suppress deterioration and failure of an electric refrigerant pump that cools a rotating electrical machine.

  A vehicle control system according to the present invention includes a power unit including a rotating electric machine, an electric refrigerant pump that circulates a refrigerant that cools the rotating electric machine, and a control that changes a driving condition of the electric refrigerant pump according to the refrigerant temperature of the electric refrigerant pump. And a device.

  In the vehicle control system according to the present invention, the control device preferably changes the driving condition of the electric refrigerant pump by changing the on / off duty value of the electric refrigerant pump.

  In the vehicle control system according to the present invention, the control device preferably changes the on / off duty according to the refrigerant temperature so as to maintain the discharge pressure or flow rate of the electric refrigerant pump constant.

  With the above configuration, the vehicle control system changes the driving condition of the electric refrigerant pump according to the refrigerant temperature of the electric refrigerant pump. When the temperature of the refrigerant changes, the viscosity of the refrigerant changes. When the driving condition of the electric refrigerant pump is constant, the discharge pressure and the flow rate change. According to the above configuration, it is possible to set the drive condition so that the change in the discharge pressure or the change in the flow rate is suppressed even if the refrigerant temperature of the electric refrigerant pump changes.

  In the vehicle control system, the driving condition of the electric refrigerant pump is changed by changing the on / off duty value of the electric refrigerant pump. For example, if the electric motor that drives the electric refrigerant pump is driven by PWM (Pulse Width Modulation) control, the driving condition of the electric refrigerant pump can be easily changed by changing the on / off duty in PWM control.

  In the vehicle control system, the on / off duty is changed according to the refrigerant temperature so that the discharge pressure or flow rate of the electric refrigerant pump is kept constant, so that the refrigerant is supplied at a constant discharge pressure regardless of the refrigerant temperature. Or a constant amount of flow can be supplied. Thereby, regardless of the refrigerant temperature, the rotating electrical machine can be appropriately cooled.

It is a figure which shows the structure of the vehicle control system in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a figure which shows a mode that the drive conditions of an electric oil pump are changed so that the flow volume of a refrigerant | coolant can be maintained constant, even if the temperature of a refrigerant | coolant changes. In the method of FIG. 2, it is a figure which shows the relationship between the temperature of a refrigerant | coolant, and electric oil pump non-off duty. In embodiment which concerns on this invention, it is a figure which shows a mode that the drive conditions of an electric oil pump are changed so that the discharge pressure of a refrigerant | coolant can be maintained constant, even if the temperature of a refrigerant | coolant changes. FIG. 5 is a diagram showing the relationship between the refrigerant temperature and the electric oil pump ON / OFF duty in the method of FIG. 4. In another embodiment, it is a figure which shows a mode that the output of an electric oil pump is changed in step shape based on the temperature of a rotary electric machine. It is a figure which shows a mode that the output of an electric oil pump is changed continuously based on the temperature of a rotary electric machine in the modification of FIG. It is a figure which shows a mode that the output of an electric oil pump is changed based on the temperature of a rotary electric machine, and the output of a rotary electric machine in another modification of FIG. It is a figure which shows a mode that the operation | movement period when an electric oil pump becomes the maximum output is restrict | limited in another modification of FIG.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following, a hybrid vehicle on which an engine and a rotating electrical machine are mounted will be described as a vehicle. However, this is an example for explanation, and any vehicle including a rotating electrical machine may be used. For example, an electric vehicle without an engine may be used. Moreover, although the structure which has an engine, one rotary electric machine, and the power transmission mechanism provided between it as a power supply device of a hybrid vehicle is demonstrated, this is also the illustration for description. Here, the hybrid vehicle only needs to have 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 the following, ATF, which is also used as a lubricating oil as a refrigerant for cooling a rotating electrical machine, will be described, but this is an example, and other cooling fluids may be used. Accordingly, the notation of an oil pump is used for the refrigerant pump that circulates the refrigerant, and this is also adapted to the case where ATF is used.

  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. This vehicle control system 10 is a system including a cooling structure 12 for a rotating electrical machine 20 mounted on a hybrid vehicle and a control device 80.

  The cooling structure 12 includes an engine 16 and a rotating electric machine 20 shown as M / G in FIG. 1 as a power unit 14 that is a driving source of the hybrid vehicle, and an M / G driving circuit 30 connected to the rotating electric machine 20 and its A high voltage power supply 32 that is a power supply is included. The cooling structure 12 further includes an oil pump unit 40 that circulates and supplies the refrigerant 26 into the case body 24 that includes the rotating electrical machine 20. The oil pump unit 40 includes a mechanical oil pump 42 shown as MOP in FIG. 1 and an electric oil pump 44 shown as EOP.

  The power unit 14 includes an engine 16, a rotating electrical machine 20, and a power transmission mechanism 18 provided therebetween. The engine 16 is an internal combustion engine. The rotating electrical machine 20 is a motor / generator (M / G) mounted on the hybrid vehicle, and functions as a motor when electric power is supplied from the M / G drive circuit 30, and when driven by the engine 16, Alternatively, it is a three-phase synchronous rotating electric machine that functions as a generator during braking of a hybrid vehicle.

The temperature detector 27 provided in the rotating electrical machine 20 is rotating electrical machine temperature detection means for detecting the temperature θ _M of the rotating electrical machine 20. The detection data of the temperature detector 27 is transmitted to the control device 80 using an appropriate signal line (not shown).

  The power transmission mechanism 18 is a mechanism having a function of distributing the power supplied to the hybrid vehicle between the output of the engine 16 and the output of the rotating electrical machine 20. As the power transmission mechanism 18, a planetary gear mechanism connected to three shafts, that is, an output shaft of the engine 16, an output shaft of the rotating electrical machine 20, and an output shaft to an axle (not shown) can be used. In FIG. 1, the shaft connecting the power transmission mechanism 18 and the engine 16 is the output shaft 22 of the engine 16. The output shaft 22 is connected to the drive shaft of the mechanical oil pump 42 via the connection shaft 70 and is used to drive the mechanical oil pump 42.

  The M / G drive circuit 30 is a circuit including an inverter that performs power conversion between the DC power of the high-voltage power supply 32 and the AC power for driving the rotating electrical machine 20. The inverter is a circuit that generates a three-phase drive signal by PWM (Pulse Width 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 20. The PWM control is a 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 20 and a carrier signal having a sawtooth waveform. The inverter brings the output of the rotating electrical machine 20 into a desired operation state by this PWM control.

  The high voltage power source 32 is a chargeable / dischargeable high voltage secondary battery. Specifically, it can be composed of 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 high voltage power supply 32, a nickel-metal hydride battery, a large capacity capacitor, or the like can be used.

  The case body 24 is a housing that includes the power transmission mechanism 18 and the rotating electrical machine 20 inside. The interior space of the case body 24 stores a coolant 26 for lubricating the movable parts of the power transmission mechanism 18 and the rotating electrical machine 20 and cooling the power transmission mechanism 18 and the rotating electrical machine 20. As the refrigerant, a lubricating oil called ATF can be used.

The temperature detector 28 provided in the case body 24 is a refrigerant temperature detection unit that detects the temperature θ _{C of the} refrigerant 26. The detection data of the temperature detector 28 is transmitted to the control device 80 using an appropriate signal line (not shown).

  The oil pump unit 40 is a unit including a mechanical oil pump 42 and an electric oil pump 44, and is a refrigerant pump unit that circulates and supplies the refrigerant 26 to the internal space of the case body 24. The refrigerant discharge path 60 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 24 along the direction of gravity, that is, at a location near the bottom of the case body 24. The refrigerant supply path 62 is a refrigerant distribution pipe that connects the oil pump unit 40 and an upper side of the case body 24 along the direction of gravity, that is, a refrigerant supply port provided at a location near the ceiling of the case body 24. The oil cooler 50 is a heat exchanger that reduces the temperature of the refrigerant 26 by air cooling or water cooling.

  The mechanical oil pump 42 is a mechanical refrigerant pump whose drive shaft is connected to the output shaft 22 of the engine 16 via the connection shaft 70 and is driven when the engine 16 operates. In other words, the mechanical oil pump 42 starts to be driven as the engine 16 is started, and when the engine 16 is stopped, the driving of the mechanical oil pump 42 is ended.

  The electric oil pump 44 is an electric refrigerant pump that is driven by the EOP drive circuit 72 under a control signal from the control device 80. The EOP drive circuit 72 is supplied with DC power from a low voltage power supply 74. The low voltage means a low voltage compared to the voltage of the high voltage power supply 32. 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 72 includes an inverter having a DC / AC conversion function. Moreover, the output of the electric oil pump 44 can be varied by changing the on / off duty in the PWM control of the inverter.

  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 72 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 60 and the refrigerant supply path 62. The check valve 46 is a valve provided so that the refrigerant 26 does not flow back between the mechanical oil pump 42 and the refrigerant supply port of the case body 24. Similarly, the check valve 48 is a valve provided so that the refrigerant 26 does not flow backward between the electric oil pump 44 and the refrigerant supply port of the case body 24.

The control device 80 has a function of controlling each of the above elements as a whole, but particularly here, the driving condition of the electric oil pump 44 is changed in accordance with the temperature θ _C of the refrigerant 26 that cools the rotating electrical machine 20, and the refrigerant Regardless of the temperature of 26, it has a function of performing control to maintain the flow rate or discharge pressure of the refrigerant 26 constant. Further, the electric oil pump 44 has a function of controlling the load of the electric oil pump 44 appropriately based on the temperature θ _M of the rotating electrical machine 20 and, if necessary, based on the torque T _M of the rotating electrical machine 20. Such a control device 80 can be configured by a computer suitable for mounting on a hybrid vehicle.

The control device 80 includes an EOP duty changing unit 82 that changes the on / off duty of the electric oil pump 44 and the electric oil pump 44 in order to control the electric oil pump 44 in consideration of a change in the temperature θ _C of the refrigerant 26. And an EOP discharge characteristic control unit 84 that performs control for maintaining the flow rate or discharge pressure constant. Further, in order to control the electric oil pump 44 to have an appropriate load, the rotating electric machine torque determination unit 86 is configured to determine whether or not the torque of the rotating electric machine 20 is equal to or greater than a predetermined threshold torque. These functions can be realized by executing software. Specifically, it can be realized by executing an EOP control program.

The operation of the above configuration will be described in detail with reference to FIG. 2 to 5 are diagrams for explaining the operation control of the electric oil pump 44 in consideration of the change in the temperature θ _{C of the} refrigerant 26.

FIG. 2 is a diagram showing a state in which the driving condition of the electric oil pump 44 is changed so that the flow rate Q of the refrigerant 26 can be kept constant even when the temperature θ _C of the refrigerant 26 changes.
Here, the load resistance characteristic line of the refrigerant 26 and the output characteristic line of the electric oil pump 44 will be described.

In order to increase the flow rate Q when the temperature θ _{C of the} refrigerant 26 used in the electric oil pump 44 is constant, it is necessary to increase the discharge pressure P. As described above, the characteristic that the flow rate Q of the refrigerant 26 flowing through the flow path increases as the discharge pressure P increases is referred to as a load resistance characteristic line of the refrigerant 26. In FIG. 2, the curves with the labels θ _C1 and θ _C2 are the load resistance characteristic lines. When the temperature θ _{C of the} refrigerant 26 changes, the load resistance characteristic line changes. As the temperature θ _C increases, the flow rate Q under the same discharge pressure P increases. In Figure 2, but compared with the theta _C1 theta _C2 is higher than the load resistance characteristic line at the load resistance characteristic line theta _C1 in theta _C2, when compared at the same discharge pressure P, it has become a large flow rate side It is shown.

  On the other hand, when the drive condition of the electric oil pump 44 is constant, the flow rate Q increases as the load on the flow path through which the refrigerant 26 flows decreases. The flow path load is indicated by the discharge pressure P. The smaller the discharge pressure P, the larger the flow rate Q. Thus, the characteristic that the flow rate Q of the refrigerant 26 that flows through the flow path increases as the discharge pressure P decreases is referred to as an output characteristic line of the electric oil pump 44. When the driving condition of the electric oil pump 44 changes, the output characteristic line changes.

As an indication of the driving conditions, the on / off duty D of the electric oil pump 44 can be used. In FIG. 2, the curves marked with D _X and D _Y are output characteristic lines. When the on / off duty D, which is the driving condition, changes, the output characteristic line changes. As the on / off duty D increases, the flow rate Q under the same discharge pressure P increases. In Figure 2, is a D _Y is small on-off-duty compared to D _X, than the output characteristic line in the on-off duty D is output characteristic curve in the large D _X D _Y, when compared at the same discharge pressure P It is shown that it is on the large flow rate side.

The operating point when the refrigerant 26 is sent out using the electric oil pump 44 is the discharge pressure P at the intersection of the load resistance characteristic line determined by the temperature θ _C of the refrigerant 26 and the output characteristic line determined by the driving conditions of the electric oil pump 44. And the flow rate Q.

2 (a) shows the load resistance characteristic line when the temperature theta _C is any theta _C1 refrigerant 26, on-off duty D of the electric oil pump 44 is an output characteristic curve of the at any time D _X FIG. The operating point is the intersection of the load resistance characteristic line at θ _C1 and the output characteristic line at D _X , and is the position indicated by discharge pressure P = P ₀ and flow rate Q = Q ₀ .

FIG. 2B is a diagram showing changes in the operating point when the on / off duty of the electric oil pump 44 remains D _X and the temperature of the refrigerant 26 changes from θ _C1 to θ _C2 . The operating point at this time is the intersection of the load resistance characteristic line at θ _C2 and the output characteristic line at D _X , and is the position indicated by the discharge pressure P = P ₁ and the flow rate Q = Q ₁ . As described above, when the temperature θ _C of the refrigerant 26 changes while the on / off duty that is the driving condition of the electric oil pump 44 is constant, the discharge pressure P and the flow rate Q also change.

FIG. 2 (c) is a diagram showing how the on / off duty for maintaining the flow rate Q at the initial Q ₀ is obtained for the operating point when the temperature of the refrigerant 26 changes from θ _C1 to θ _C2 . . For this purpose, output characteristic lines having different on / off duties must be obtained in advance. Then, among the plurality of output characteristic lines having different on / off duties, the one having the flow rate Q at the operating point intersecting with the load resistance characteristic line at θ _C2 is selected as Q ₀ . In FIG. 2 (c), the on-off duty at the operating point crossing the load resistance characteristic line when the output characteristic line theta _C2 of D _Y, is a discharge pressure P = P _Y is a flow rate Q = Q ₁ Is shown.

That is, when the temperature of the refrigerant 26 changes from θ _C1 to θ _C2 , the flow rate Q of the refrigerant 26 is kept constant by changing the on / off duty as the driving condition of the electric oil pump 44 from D _X to D _Y. Q ₀ can be maintained. Here, changing the on / off duty of the electric oil pump 44 is performed by the function of the EOP duty changing unit 82 of the control device 80. Further, the on / off duty of the electric oil pump 44 is changed by the function of the EOP discharge characteristic control unit 84 of the control device 80 so as to maintain the flow rate Q of the refrigerant 26 at a constant Q ₀ .

FIG. 3 is a diagram showing the relationship between the on / off duty D and θ _C under the condition for maintaining the flow rate Q of the refrigerant 26 at a constant value using the method described in FIG. 2. By obtaining such a characteristic diagram in advance, when the temperature θ _C of the refrigerant 26 changes, if the electric oil pump 44 is operated using the on / off duty D corresponding to the temperature θ _C , The flow rate Q of the refrigerant 26 can be maintained at a constant value. As shown in FIG. 3, when the temperature θ _C of the refrigerant 26 increases, the on / off duty D needs to be reduced in order to maintain the flow rate Q at a constant value.

FIG. 4 is a diagram showing a state in which the driving condition of the electric oil pump 44 is changed so that the flow rate Q of the refrigerant 26 can be kept constant even when the temperature θ _C of the refrigerant 26 changes.
Here, FIG. 4 (a), the output characteristic when the temperature theta _C and a load resistance characteristic line when the arbitrary theta _C1, on-off duty D of the electric oil pump 44 is any D _X of refrigerant 26 It is a figure which shows a line, and is the same content as Fig.2 (a). 4 (b) is, on-off duty ratio of the electric oil pump 44 remains D _X, a diagram showing a change in the operating point when the temperature of the coolant 26 changes from theta _C1 to theta _C2, FIG. The content is the same as 2 (b). Therefore, detailed description thereof will be omitted.

FIG. 4C is a diagram showing a state in which the on / off duty for maintaining the discharge pressure P at the initial P ₀ is obtained for the operating point when the temperature of the refrigerant 26 changes from θ _C1 to θ _C2 . is there. For this purpose, output characteristic lines having different on / off duties must be obtained in advance. Then, a plurality of output characteristic lines having different on / off duties are selected so that the discharge pressure P at the operating point intersecting with the load resistance characteristic line at θ _C2 is P ₀ . In FIG. 4C, the flow rate Q = Q _Z at the operating point where the output characteristic line with the ON / OFF duty of D _Z and the load resistance characteristic line when θ _C2 intersects, but the discharge pressure P = P ₀ . It is shown that there is.

That is, when the temperature of the refrigerant 26 changes from θ _C1 to θ _C2 , the discharge pressure P of the refrigerant 26 is changed by changing the on / off duty as the driving condition of the electric oil pump 44 from D _X to D _Z. A constant P ₀ can be maintained.

FIG. 5 is a diagram showing the relationship between the on / off duty D and θ _C under the condition for maintaining the discharge pressure P of the refrigerant 26 at a constant value using the method described in FIG. 4. By obtaining such a characteristic diagram in advance, when the temperature θ _C of the refrigerant 26 changes, if the electric oil pump 44 is operated using the on / off duty D corresponding to the temperature θ _C , The discharge pressure P of the refrigerant 26 can be maintained at a constant value. As shown in FIG. 5, when the temperature θ _C of the refrigerant 26 increases, the on / off duty D needs to be increased in order to maintain the discharge pressure P at a constant value. Here, the ON / OFF duty of the electric oil pump 44 is changed by the function of the EOP discharge characteristic control unit 84 of the control device 80 so as to maintain the discharge pressure P at a constant P ₀ .

Thus, by changing the on / off duty of the PWM control in the EOP drive circuit 72, the flow rate Q or the discharge pressure P of the electric oil pump 44 is made constant even if the temperature θ _C of the refrigerant 26 changes. Control can be performed. By making the flow rate Q constant, the rotating electrical machine 20 can be prevented from being overcooled or insufficiently cooled to have an appropriate cooling performance, and the power consumption of the electric oil pump 44 can be maintained at an appropriate level. Further, by making the discharge pressure P constant, when the refrigerant 26 is used for other hydraulic pressure control, a stable hydraulic pressure can be supplied.

  Next, control for making the load and operating time of the electric oil pump 44 appropriate will be described. In the prior art, the operation control of the electric oil pump 44 is only a two-stage control of operation / non-operation, and when operated, the output is constant. As described above, in the case of only the two-stage control of operation / non-operation, the electric oil pump 44 has an excessive load and operation time with respect to the cooling performance of the rotating electrical machine 20. The deterioration of the product may be accelerated, leading to failure. When the electric oil pump 44 is deteriorated or malfunctioned, the cooling performance of the rotating electrical machine 20 is limited, and the power economy of the rotating electrical machine 20 is reduced.

  Therefore, by using the on / off duty changing technique described above, the output of the electric oil pump 44 is varied in accordance with the change in the temperature θM of the rotating electrical machine 20, and the load and operation time of the electric oil pump 44 are made appropriate. Can do. The contents will be described in detail with reference to FIG.

FIG. 6 is a diagram illustrating a state in which the output of the electric oil pump 44 is changed in a step shape based on the temperature θ _M of the rotating electrical machine 20 to make the load of the electric oil pump 44 appropriate. FIG. 6A is a diagram showing a change in the temperature θ _M of the rotating electrical machine 20, where the horizontal axis is time and the vertical axis is θ _M. Here, two-stage threshold temperatures are set for θ _M.

One is a first threshold temperature theta _M1, the temperature theta _M of the rotating electrical machine 20 becomes the threshold temperature theta _M1 above, the electric oil pump 44 is actuated threshold to start operating. The output when the electric oil pump 44 starts operating is not the maximum, but is a predetermined output set in advance as a smaller value. When the on / off duty D is used to indicate the output of the electric oil pump 44, the on / off duty D when the electric oil pump 44 starts to operate is a predetermined D smaller than the maximum on / off duty _{DMAX. 0} .

The other is at the second threshold temperature theta _M2, temperature theta _M of the rotating electrical machine 20 becomes more than the threshold temperature theta _M, the output of the electric oil pump 44 is maximum output threshold becomes maximum. In terms of the on / off duty D, the maximum D _MAX is set.

In FIG. 6B, the horizontal axis represents time, and the vertical axis represents the ON / OFF state for the operation of the electric oil pump 44. The ON state is an operating state, and the OFF state is an inactive state. Here, it is shown that the operation starts from time t ₁ when the temperature θ _M of the rotating electrical machine 20 becomes equal to or higher than the first threshold temperature θ _M1 .

In FIG. 6C, the horizontal axis represents time, the vertical axis represents the output of the electric oil pump 44, and the on / off duty D is taken here. As shown in FIG. 6C, the on / off duty D is 0% until the temperature θ _M of the rotating electrical machine 20 becomes equal to or higher than the first threshold temperature θ _M1 , and θ _M is equal to or higher than the first threshold temperature θ _M1. is a from becoming time t ₁ theta _M until time t ₂ which is a second threshold temperature theta _M2 or _0% on-off-duty D = D, theta _{time M} becomes the second threshold temperature theta _M2 or After t ₂ , the on / off duty D = D _MAX %.

In the prior art, the output during operation when the control of the electric oil pump 44 is in the two-stage control of whether to operate or not is in a state of D _MAX where the on / off duty D is maximum. In the case of FIG. 6, when the temperature θ _M of the rotating electrical machine 20 rises to become the first threshold temperature θ _M1 or more and cooling by supplying the refrigerant 26 of the electric oil pump 44 becomes necessary, it is immediately turned on / off. The duty D is not set to D _MAX but is set to a predetermined D ₀ lower than that. Only when the temperature θ _M further rises to the second threshold temperature θ _M2 , the on / off duty D is set to the maximum D _MAX . As described above, even when the rotating electrical machine 20 needs to be cooled, when the temperature θ _M is low, the on / off duty D is not set to the maximum D _MAX , thereby ensuring the cooling performance of the rotating electrical machine 20 and the electric oil. The load of the pump 44 can be made appropriate. Thereby, the rotating electrical machine 20 is not overcooled, and the power consumption of the electric oil pump 44 can be appropriately reduced.

In FIG. 6, the on / off duty D is changed stepwise between the first threshold temperature θ _M1 and the second threshold temperature θ _M2 , but this is continuously varied according to the temperature θ _M of the rotating electrical machine 20. It may be a thing. FIG. 7 is a diagram showing such an example. FIG. 7A has the same contents as FIG. 6A, and FIG. 7B has the same contents as FIG.

The horizontal and vertical axes in FIG. 7C are the same as those in FIG. Here, ON until the temperature theta _M is the first threshold temperature theta _M1 or more on-off-duty D = 0%, θ _M at time t ₁ became the first threshold temperature theta _M1 or more rotary electric machine 20 off it raised the duty D = D _0%, θ _M is turned on and off-duty D = D _MAX% in time t ₂ to be the second threshold temperature theta _M2 or more. Then, between the first threshold temperature θ _M1 and the second threshold temperature θ _M2 , the on / off duty D continuously increases from D ₀ % to D _MAX % according to the increase in the temperature θ _M of the rotating electrical machine 20. Enhanced.

  In this way, the load of the electric oil pump 44 can be made appropriate while ensuring the cooling performance necessary for the rotating electrical machine 20.

In FIG. 7, the on / off duty D is changed between the first threshold temperature θ _M1 and the second threshold temperature θ _M2 based on the change in the temperature θ _M of the rotating electrical machine 20. it may alternatively be changed in response to changes in the torque T _M. FIG. 8 is a diagram showing such an example.

The horizontal and vertical axes in FIG. 8A are the same as those in FIG. Here, one threshold temperature θ _M0 is set for the temperature θ _M of the rotating electrical machine 20. The threshold temperature theta _M is the temperature theta _M of the rotating electrical machine 20 becomes the threshold temperature theta _M0 above, the electric oil pump 44 is actuated threshold to start operating.

FIG. 8B is a diagram showing a change in the torque T _M of the rotating electrical machine 20, where the horizontal axis represents time and the vertical axis represents the torque T _M of the rotating electrical machine 20. Here, one threshold torque T _M0 is set for the torque T _M of the rotating electrical machine 20. The threshold torque T _M0, the torque T _M of the rotary electric machine 20 When this threshold torque T _M0 above, the output of the electric oil pump 44 is maximum output threshold becomes maximum.

  FIG. 8C is a diagram showing the operation and stop of the electric oil pump 44. Since this content is the same as FIG. 7B, detailed description is omitted.

FIG. 8D is a diagram corresponding to FIG. Here, ON until the temperature theta _M is the first threshold temperature theta _M1 or more on-off-duty D = 0%, θ _M at time t ₁ became the first threshold temperature theta _M1 or more rotary electric machine 20 • Off duty D is increased to D ₀ %. Then, the on / off duty D = D _MAX % is set at time t ₂ when the torque T _M of the rotating electrical machine 20 becomes equal to or greater than the threshold torque T _M0 . During the period from time t ₁ to time t ₂ , the on / off duty D is continuously increased from D ₀ % to D _MAX % according to the increase in the torque T _M of the rotating electrical machine 20. The determination of whether or not the torque T _M of the rotating electrical machine 20 is _{equal to} or greater than the threshold torque T _M0 is performed by the function of the rotating electrical machine torque determining unit 86 of the control device 80.

  In this way, the load of the electric oil pump 44 can be made appropriate while ensuring the cooling performance necessary for the rotating electrical machine 20.

In the above description, when the temperature θ _M of the rotating electrical machine 20 is equal to or higher than the threshold temperature, or the torque T _M of the rotating electrical machine 20 is equal to or higher than the threshold torque, the output of the electric oil pump 44 is maximized. If the operation of the electric oil pump 44 is continued with the maximum output, the deterioration of the electric oil pump 44 proceeds and a failure is likely to occur. Therefore, it is preferable to limit the maximum output period of the electric oil pump 44. FIG. 9 is a diagram showing such an example.

  Since FIG. 9A is the same as FIG. 6A, detailed description is omitted. The horizontal and vertical axes in FIG. 9B are the same as those in FIG. 6B, except that the time is extended until the electric oil pump 44 is stopped after being operated.

FIG. 9C is a diagram corresponding to FIG. The horizontal and vertical axes are the same as in FIG. Here, after a time t ₂ when the on / off duty D of the electric oil pump 44 becomes D _MAX at time t ₂ , a time when a preset predetermined period T ₀ has elapsed (t ₂ + T ₀ ). Then, the operation of the electric oil pump 44 is stopped, and the on / off duty D = 0%.

  In this way, by limiting the maximum output period of the electric oil pump 44, deterioration and failure of the electric oil pump 44 can be suppressed.

As described above, with respect to performing the operation control of the electric oil pump 44 according to the temperature θ _M of the rotating electrical machine 20, in the vehicle control system according to the present invention, the control device operates according to the temperature of the rotating electrical machine. It is preferable to change the output of the pump. In this case, it is preferable to change the output of the electric oil pump by changing the on / off duty value of the electric oil pump.

  For example, when the temperature of the rotating electrical machine is low, the output of the electric oil pump is made lower compared to when the temperature of the rotating electrical machine is high, so that the output of the electric oil pump is always constant. The power consumption of the electric oil pump can be reduced, and the power economy can be improved. Moreover, the heat generation of the drive circuit of the electric oil pump can be suppressed, and the life of the electric oil pump system can be extended.

  Further, in the vehicle control system according to the present invention, when the temperature of the rotating electrical machine exceeds a predetermined first threshold temperature, the control device starts operation with the output of the electric oil pump as a predetermined output, It is preferable to change the output of the electric oil pump to the maximum output when a predetermined second threshold temperature higher than the first threshold temperature is exceeded.

  By doing so, it is possible to reduce the power consumption of the electric oil pump and improve the economics of electric power as compared with the case where the output of the electric oil pump is always the maximum output. Moreover, the heat generation of the drive circuit of the electric oil pump can be suppressed, and the deterioration and failure of the electric oil pump system can be suppressed and the life can be extended.

  In the vehicle control system according to the present invention, the control device changes the output of the electric oil pump from a predetermined output to a maximum output according to the temperature in a temperature range between the first threshold temperature and the second threshold temperature. Is preferred.

  By doing so, the rotating electrical machine can be efficiently cooled while reducing the power consumption of the electric oil pump. Moreover, the heat generation of the drive circuit of the electric oil pump can be suppressed, and the deterioration and failure of the electric oil pump system can be suppressed and the life can be extended.

  In the vehicle control system according to the present invention, the control device preferably changes the output of the electric oil pump from a predetermined output according to the output of the rotating electrical machine when the temperature of the rotating electrical machine exceeds the first threshold temperature. .

  As a result, it is possible to efficiently perform cooling according to the heat generated by the rotating electrical machine while reducing the power consumption of the electric oil pump. Moreover, the heat generation of the drive circuit of the electric oil pump can be suppressed, and the deterioration and failure of the electric oil pump system can be suppressed and the life can be extended.

  In the vehicle control system according to the present invention, it is preferable that the control device stops the operation of the electric oil pump when the period of maximum output of the electric oil pump reaches a predetermined period.

  As a result, deterioration and failure of the electric oil pump can be appropriately suppressed, and the life of the electric oil pump can be extended.

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

  DESCRIPTION OF SYMBOLS 10 Vehicle control system, 12 Cooling structure, 14 Power unit, 16 Engine, 18 Power transmission mechanism, 20 Rotating electric machine, 22 Output shaft, 24 Case body, 26 Refrigerant, 27, 28 Temperature detector, 30 M / G drive circuit, 32 High-voltage power supply, 40 Oil pump unit, 42 Mechanical oil pump, 44 Electric oil pump, 46, 48 Check valve, 50 Oil cooler, 60 Refrigerant discharge path, 62 Refrigerant supply path, 70 Connection shaft, 72 EOP drive circuit 74 Low voltage power supply, 80 control device, 82 EOP duty change unit, 84 EOP discharge characteristic control unit, 86 rotating electrical machine torque determination unit.

Claims (3)

A power unit including a rotating electrical machine;
An electric refrigerant pump for circulating a refrigerant for cooling the rotating electrical machine;
A control device that changes the driving condition of the electric refrigerant pump according to the refrigerant temperature of the electric refrigerant pump;
A vehicle control system comprising: The vehicle control system according to claim 1,
The control device changes the driving condition of the electric refrigerant pump by changing the on / off duty value of the electric refrigerant pump. The vehicle control system according to claim 2,
The control device
A vehicle control system characterized by changing an on / off duty according to a refrigerant temperature so as to maintain a discharge pressure or a flow rate of an electric refrigerant pump constant.

Images