JP2017207039A - Lubrication control device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in electric power consumption caused by reverse rotation of an electric motor built in an electric oil pump for preventing clogging.SOLUTION: A suction port 40a of a strainer 40 is immersed in engine oil. The suction port 40a includes a net member 42, and an electric oil pump 50 is provided downstream of the net member 42 in a passage partitioned by the strainer 40. On the condition that an oil temperature Toil is a specified temperature or lower when a power supply switch 70 is turned on, an engine 30 is rotated at low speed and an electric motor 50a built in the electric oil pump 50 is rotated normally, so that the engine oil in an oil pan 34 is sucked from the suction port 40a and then discharged to an engine body 32 side. When pressure Poil on the engine body 32 side reaches lower than specified pressure, the electric motor 50a is rotated reversely at maximum output for a predetermined time.SELECTED DRAWING: Figure 1

Description

  The present invention provides an oil pan, a strainer having a suction port immersed in the engine oil in the oil pan and provided with a net-like member for removing foreign matter in the engine oil, and the engine oil distribution path. An engine lubrication control device for controlling a lubrication device provided between the mesh member and the engine main body and having an electric oil pump that discharges the engine oil sucked from the suction port to the engine main body side About.

  For example, Patent Document 1 proposes a lubrication device including a mechanical oil pump driven by an engine and an electric oil pump driven by an electric motor. This device is provided with a filter upstream of the mechanical oil pump, and a filter is provided at the inlet of the passage for sucking engine oil by the electric oil pump. In this device, when the mechanical oil pump is driven and the flow resistance is determined to be large due to clogging of the filter based on the current flowing through the motor of the electric oil pump, the electric motor is reversely rotated. Execute the process. As a result, foreign matter can be desorbed from the filter, and the desorbed foreign matter can be sucked by the mechanical oil pump and collected by the filter.

JP 2007-2682 A

  In the above apparatus, in order to alleviate or eliminate clogging on the electric oil pump side, it is necessary to further include a mechanical oil pump in addition to the electric oil pump and to capture foreign matter on the mechanical oil pump side. That is, for example, in the case where the machine oil pump is not provided or the foreign matter detached by reverse rotation is not captured on the mechanical oil pump side, even if the foreign matter is removed from the filter by the process of rotating the electric motor in reverse, When the electric motor is returned to the normal rotation, the filter is clogged again, and there is a possibility that the clogging cannot be appropriately dealt with.

  On the other hand, ice is considered as a factor of the clogging. In other words, the condensed water produced when the fuel burns in the engine combustion chamber is mixed into the engine oil, which may become ice when the engine is stopped. If the condensed water becomes ice, the electric oil pump is driven. The ice causes the filter to become clogged. In this case, the clogging is eliminated by increasing the temperature of the engine oil. Therefore, even when a machine oil pump is not provided or foreign matter detached due to reverse rotation is not captured on the machine oil pump side, it is caused by lubricating the engine body by rotating the motor forward. The clogging can be eliminated by repeating the process of eliminating the clogging by rotating the electric motor in the reverse direction. However, if the rotation speed of the motor when rotating the motor in the forward direction and the rotation speed of the motor when rotating the motor in the reverse direction are substantially the same, the ice discharged by rotating the motor in the reverse direction is rotated forward. By doing so, it sucks again immediately, and the frequency of reverse rotation increases. And this is because the rotation speed of the motor once becomes zero with switching from one of the forward rotation and the reverse rotation to the other, and the frequency of occurrence of the inrush current by applying the voltage to the motor at an extremely low speed increases. This leads to an increase in power consumption of the electric oil pump.

  The present invention has been made in view of such circumstances, and its purpose is to suppress an increase in power consumption due to reverse rotation of an electric motor incorporated in an electric oil pump in order to eliminate clogging. An object of the present invention is to provide an engine lubrication control device.

  In order to solve the above problems, an engine lubrication control device includes an oil pan, and a strainer having a net-like member for removing a foreign matter in the engine oil, the suction port being immersed in the engine oil in the oil pan. And an electric oil pump that is provided between the mesh member in the engine oil distribution path and the engine body and discharges the engine oil sucked from the suction port to the engine body side. And the freezing determination processing unit that determines that the water in the engine oil is frozen and the freezing determination processing unit determines that the water is frozen based on the fact that the temperature of the engine oil is equal to or lower than a specified temperature. When the engine is driven, the target rotational speed of the electric motor built in the electric oil pump is frozen. A low-speed processing unit that drives the electric oil pump to lubricate the engine body while lowering the engine body when it is not determined to freeze by a constant processing unit, and the low-speed processing unit Clogging determination for determining whether or not the mesh member is clogged based on at least one of the pressure of the engine oil and the rotation speed of the electric motor on the side of the engine main body with respect to the electric oil pump when processing is performed When it is determined by the processing unit and the clogging determination processing unit that the clogging has occurred, the motor is reversely rotated at a rotation speed higher than a target rotation speed by the low-speed processing unit, and the engine is driven by the electric oil pump. The process of sucking the fluid on the main body side and discharging it to the oil pan side is performed for a predetermined time. Comprises a reverse processing unit that, the.

  When the temperature of the engine oil falls below a specified temperature, if water is contained in the engine oil, this may freeze and cause clogging. Therefore, in the above configuration, when it is determined that clogging has occurred based on the temperature of the engine oil being equal to or lower than the specified temperature, and it is determined that clogging has occurred, clogging is prevented by driving the electric oil pump at a low speed. Lubricate the engine body while suppressing the occurrence.

  When lubricating the engine body, if the engine oil pressure on the engine body side of the engine body side is lower than the specified pressure than the electric oil pump, or if the motor speed decreases, the mesh member will be clogged with ice. It is thought that it occurred. When it is considered that clogging has occurred due to ice, the electric oil pump is driven by the reverse rotation processing unit so that the fluid on the engine body side is discharged to the oil pan side. Thereby, the ice which caused the clogging of the mesh member flows out into the oil pan, and the clogging is eliminated.

  The processing by the reverse processing unit is stopped when it continues for a predetermined time. Here, when the processing of the low speed processing unit is performed again, since the rotation speed by the low speed processing unit is lower than the rotation speed by the reverse processing unit, the low speed processing unit has a weak force to draw ice to the mesh member. For this reason, when the electric oil pump is driven by the low speed processing unit, the time required until the clogging determination is made as compared with the case where the electric oil pump is driven at a higher rotation than the processing by the low speed processing unit. Will be prolonged. Therefore, since the frequency of processing by the reverse rotation processing unit can be kept low, an increase in power consumption due to reverse rotation of the electric motor built in the electric oil pump can be suppressed to eliminate clogging.

The figure which shows one Embodiment concerning an engine lubrication control apparatus, and a lubrication apparatus. The flowchart which shows the procedure of the warm-up process of the engine oil concerning the embodiment.

Hereinafter, an embodiment of an engine lubrication control device will be described with reference to the drawings.
FIG. 1 shows a vehicle drive system according to this embodiment. The drive system shown in FIG. 1 constitutes a series / parallel hybrid system. As shown in FIG. 1, the internal combustion engine (engine 30) is mechanically coupled to the carrier C of the planetary gear mechanism (power split mechanism 10), and the motor generator 14 is mechanically coupled to the sun gear S of the power split mechanism 10. The motor generator 12 is mechanically connected to the ring gear R of the power split mechanism 10. Here, among the three rotating bodies constituting the power split mechanism 10, the sun gear S, the carrier C, and the ring gear R, in which the object is mechanically connected, means that the object first transmits power. It is a possible rotating body. Further, the drive wheel 16 is mechanically coupled to the ring gear R.

  The motor generator 12 is connected to an assembled battery (battery 24), which is a battery cell series connection body, via an inverter 18 and a system main relay (SMR22). Motor generator 14 is connected to battery 24 via inverter 20 and SMR 22. A charger 26 is connected between the SMR 22 and the battery 24 to charge the battery 24 with electric power from a commercial power supply 28 outside the vehicle.

  The engine 30 includes an engine body 32 including a cylinder block and a cylinder head, and an oil pan 34 that stores engine oil. The engine oil stored in the oil pan 34 is immersed in the suction port 40 a of the strainer 40. The suction port 40a is provided with a member (net-like member 42) having a mesh structure that restricts the inflow of foreign matters to the downstream side. An electric oil pump 50 is provided downstream of the mesh member 42 in the distribution path defined by the strainer 40. The electric oil pump 50 has a built-in electric motor 50a, sucks engine oil in the oil pan 34, and discharges it to the engine body 32 side. An oil control valve 54 is provided in part of the engine oil flow path downstream of the electric oil pump 50. The oil control valve 54 supplies engine oil to the variable valve timing device in the engine body 32 in particular.

  The control device 60 includes a central processing unit (CPU 62) and a memory 64. The control device 60 controls the inverters 18 and 20, the engine 30, the charger 26, and the like. The control device 60 controls the engine from the rotational speed sensor 72 that detects the rotational speed Np of the electric oil pump 50, the oil temperature sensor 74 that detects the temperature (oil temperature Toil) of the engine oil, and the electric oil pump 50. The output value of the pressure sensor 76 for detecting the pressure Poil of the engine oil discharged to the main body 32 side is taken in.

  When the power switch 70 is turned on by the user, the control device 60 closes the SMR 22 so that the vehicle can run. Then, the motor generators 12 and 14 and the engine 30 are driven to drive the vehicle according to the accelerator operation by the user.

  Here, the control device 60 causes the vehicle to travel using the power of the battery 24 charged by the charger 26 as much as possible. For this reason, when the charging rate of the battery 24 exceeds the specified value, the engine 30 and the motor generator 14 are stopped when sufficient power can be applied to the drive wheels 16 by the power of the motor generator 12. On the other hand, in addition to the motor generator 12, in addition to the motor generator 12, the engine 30 and the motor generator 14 are driven when the vehicle 24 is requested to travel even though the charging rate of the battery 24 has become equal to or less than the specified value. .

  Thus, in this embodiment, since the electric power of the battery 24 is used as much as possible as energy for traveling of the vehicle, the drive duration time of the engine 30 tends to be shortened. For this reason, a situation in which the temperature of the engine oil does not become 100 ° C. or more during the driving of the engine 30 tends to occur. Here, while the engine 30 is being driven, moisture contained in the fuel is mixed into the engine oil as condensed water during combustion. The condensed water mixed in the engine oil is vaporized and removed from the engine oil when the temperature of the engine oil is 100 ° C. or higher. On the other hand, when the temperature of the engine oil does not rise sufficiently, the condensed water is contained in the engine oil even after the engine 30 is stopped. The condensed water contained in the engine oil is separated from the engine oil when the engine 30 is stopped. However, since the density of water is higher than the density of engine oil, the condensed water stays at the bottom of the oil pan 34. When the condensed water is cooled below the freezing point in a cold region or the like, ice is generated in the engine oil. If the electric oil pump 50 is driven in a state where ice is present in the engine oil, the engine body 32 may not be sufficiently lubricated with the engine oil due to clogging of the mesh member 42.

Therefore, in the present embodiment, the following engine oil warm-up process is executed.
FIG. 2 shows a procedure for warming up the engine oil. The processing shown in FIG. 2 is realized by the CPU 62 executing a program stored in the memory 64. Note that the process shown in FIG. 2 is executed with the power switch 70 being switched from the off state to the on state as a trigger.

  In the series of processes shown in FIG. 2, the CPU 62 first determines whether or not the oil temperature Toil is equal to or lower than the specified temperature Tth (S10). This process is a process for determining whether or not the condensed water is frozen when the condensed water is mixed in the engine oil. That is, when the oil temperature Toil is low, the condensed water in the engine oil is solidified and ice is generated in the engine oil. Here, the specified temperature Tth is set to an upper limit value (for example, 0 ° C.) of the temperature at which ice is present in the engine oil.

  When determining that the temperature is equal to or lower than the specified temperature Tth (S10: YES), the CPU 62 determines whether condensed water was present in the engine oil when the engine 30 was stopped last time (S12). In this process, the CPU 62 sequentially executes a process of estimating the water content in the engine oil when the engine 30 was driven last time, and stores the final water content in the memory 64 when the engine 30 is stopped. This can be achieved. Here, for example, when the oil temperature Toil is less than 100 ° C., the moisture amount estimation process integrates a value obtained by multiplying a predetermined coefficient by a predetermined coefficient as a moisture amount mixed into the engine oil each time, When the oil temperature Toil is 100 ° C. or higher, it may be executed by correcting the amount of water as the amount of water in the engine oil to be reduced at a predetermined period. Note that the lower limit of the weight-corrected value is zero.

  When the CPU 62 determines that condensed water is present (S12: YES), there is a possibility that ice is present in the oil pan 34, and the mesh member 42 is clogged, thereby hindering lubrication of the engine body 32. If there is, the engine 30 is operated at a low speed to warm up the engine oil (S14). This is intended to reduce the flow rate of the engine oil necessary for lubricating the engine body 32 by limiting the rotational speed of the engine 30. Further, in this process, the oil control valve 54 is closed and the variable valve timing device is not driven. This is a setting for reducing the amount of engine oil to be supplied to the engine body 32 side by the electric oil pump 50 as much as possible.

  The CPU 62 drives the electric oil pump 50 and supplies the engine oil in the oil pan 34 to the engine body 32 side as the engine 30 is operated at a low speed (S16). Here, the voltage applied to the electric motor 50a is manipulated in order to feedback control the rotational speed Np of the electric motor 50a to the target rotational speed. Here, the target rotation speed is set to a low value as compared with the average value of the rotation speed of the electric motor 50a when the engine 30 is driven without performing the low rotation operation. This is because the required flow rate of the engine oil is smaller when the engine 30 is operated at a low speed than when the engine 30 is operated at a high speed.

  Then, the CPU 62 determines whether or not the pressure Poil is equal to or lower than the specified pressure Pth (S18). This process is for determining whether or not the mesh member 42 is clogged. That is, since the mesh member 42 is provided on the upstream side of the electric oil pump 50, when the mesh member 42 is clogged, a sufficient amount of engine oil can be discharged from the electric oil pump 50. The pressure Poil is lower than when it is not clogged. The specified pressure Pth is set to the upper limit value of the pressure Poil when the clogging degree of the mesh member 42 is out of the allowable range. Incidentally, the upper limit value is a value lower than the target value of the pressure Poil.

  When determining that the pressure is higher than the specified pressure Pth (S18: NO), the CPU 62 returns to the process of step S10. On the other hand, when the CPU 62 determines that the pressure is equal to or lower than the specified pressure Pth (S18: YES), the engine 30 is stopped (S20), the electric motor 50a is rotated in reverse, and the electric oil pump 50 causes the fluid on the engine body 32 side to be oiled. It is discharged to the pan 34 side (S22). Here, the electric oil pump 50 is driven at the maximum output with the applied voltage to the electric motor 50a as the maximum value that can be applied.

  The CPU 62 stands by until the duration of the process of rotating the electric motor 50a reversely reaches a predetermined time (S24: NO). When the predetermined time is reached (S24: YES), the CPU 62 returns to the process of step S10.

If the CPU 62 makes a negative determination in steps S10 and S12, it ends the process shown in FIG.
Here, the operation of the present embodiment will be described.

  When the user gets into the vehicle and the power switch 70 is turned on, the CPU 62 drives the electric oil pump 50 and lubricates the engine body 32 based on the oil temperature Toil and the state when the engine 30 is driven. When it is assumed, it is determined whether or not the mesh member 42 is clogged with ice and hinders lubrication. Then, when the CPU 62 determines that a problem is caused, it drives the engine 30 at a low speed. In this case, since the supply amount of engine oil required for lubricating the engine body 32 per unit time is small, the electric oil pump 50 is driven at a low rotational speed. When the electric oil pump 50 is driven at a low speed, the force of the ice in the oil pan 34 being sucked toward the strainer 40 is weaker than when the electric oil pump 50 is driven at a high speed. The progress speed of clogging can be reduced. For this reason, compared with the case where the electric oil pump 50 is not driven at low rotation, the time when the degree of clogging is out of the allowable range can be delayed.

  Then, when the degree of clogging of the mesh member 42 is outside the allowable range, the CPU 62 temporarily stops the engine 30 and reversely rotates the electric motor 50a to drive the electric oil pump 50 with the maximum output. As a result, the clogging of the mesh member 42 is eliminated at once, and the ice is further moved away from the strainer 40 as much as possible. Then, when the predetermined time has elapsed, the CPU 62 causes the engine 30 to run at a low speed again, and resumes the lubrication process of the engine main body 32 by the electric oil pump 50. By repeating these processes, the ice in the oil pan 34 melts when the oil temperature Toil reaches zero degrees or more, so that the engine 30 is ready to be driven normally.

  When the engine 30 is operated at a low speed, the CPU 62 performs a power generation process that converts the power of the engine 30 into electric power by the motor generator 14. Incidentally, when the engine 30 is operated at a low speed, the CPU 62 basically causes the vehicle to run with the power of the motor generator 12.

According to the embodiment described above, the following effects can be obtained.
(1) When there is a possibility that the water in the engine oil may freeze, the engine 30 was driven at a low speed. As a result, the flow rate of the engine oil necessary for lubricating the engine body 32 can be reduced, so that the engine oil required for the engine body 32 can be supplied while the electric oil pump 50 is driven at a low speed. it can.

  (2) When there is a possibility that water in the engine oil may freeze, the oil control valve 54 is closed. Thereby, the discharge flow rate of the engine oil required for the electric oil pump 50 can be reduced.

  (3) The engine 30 is operated at a low speed by using the power switch 70 to be turned on as a trigger. As a result, the engine oil can be warmed up at an early stage, and as a result, the engine 30 can be operated at a high output at an early stage.

<Correspondence>
Correspondences between the items described in the column of “Means for Solving the Problems” and items in the embodiment are as follows. In the following, “CPU 62 that executes a predetermined process according to a program stored in memory 64” will be referred to as “CPU 62 that executes a predetermined process” in order to simplify the description. The freezing determination processing unit corresponds to the CPU 62 that executes the processing of steps S10 and S12, the low speed processing unit corresponds to the CPU 62 that executes the processing of step S16, and the clogging determination processing unit executes the processing of step S18. The reverse rotation processing unit corresponds to the CPU 62 that executes the processes of steps S22 and S24. The lubrication control device corresponds to the control device 60.

<Other embodiments>
In addition, you may change at least 1 of each matter of the said embodiment as follows.
In the above configuration, when the engine 30 is operated at a low speed, the motor generator 14 performs the power generation process, but the present invention is not limited to this. For example, a low-rotation operation of the engine 30 may be set as an idling operation by providing a clutch between the engine 30 and the power split mechanism 10 and keeping it in a disconnected state.

  In the above embodiment, the engine 30 is stopped when the electric motor 50a is reversely rotated. However, the present invention is not limited to this, and the duration of the reverse rotation process is set within a range in which poor lubrication of the engine 30 can be tolerated. The electric motor 50a may be reversely rotated while the engine 30 is driven.

  For example, in the process of step S18, when the rotation speed Np is equal to or less than a predetermined value, it may be determined that the mesh member 42 is clogged. For example, the rotation speed Np is equal to or less than a predetermined value, When the logical sum that the Poil is equal to or less than the specified pressure Pth is true, it may be determined that the mesh member 42 is clogged.

  The hybrid vehicle is not limited to one that can charge the battery 24 with electric power from outside the vehicle. Even if the battery 24 has a small capacity, such as a battery that cannot be charged, the engine oil contains moisture when it is left to stand after being driven for a few minutes in a cold region. It will be left as it is. For this reason, there is a possibility that ice may be generated in the engine oil while the engine 30 is stopped. Therefore, the processing shown in FIG. 2 and its modification are effective.

  -Not limited to series / parallel hybrid vehicles. For example, a parallel hybrid vehicle or a series hybrid vehicle may be used. Of course, even if the engine is the only engine that powers the drive wheels, not only the hybrid vehicle, but if the engine stops after traveling a short distance in a cold region, the engine oil contains moisture. Then, when an extremely rare case of leaving it for a long time occurs, clogging may occur. For this reason, for example, it is effective to execute the processes of steps S10 to S18, S22, and S24 in FIG. 2 with the ignition switch being turned on as a trigger. In this case, it is desirable to limit the output of the engine 30 and notify the user to that effect until the engine oil has been warmed up.

  The control device 60 is not limited to the software processing performed by the CPU 62 for all of the processing shown in FIG. For example, the control device 60 includes an ASIC that executes at least a part of processing such as processing of steps S22 and S24 by dedicated hardware (application-specific integrated circuit: ASIC). Also good. When the ASIC executes the processes in steps S22 and S24, the ASIC outputs a signal to that effect to the CPU 62 when an affirmative determination is made in step S24.

  Further, for example, apart from hardware for controlling the control amount of the engine 30 (hereinafter referred to as first hardware) and hardware for executing processing for operating the electric oil pump 50 (hereinafter referred to as second hardware). Also good. This is because the first hardware executes the process of step S14 in FIG. 2 and the process of step S20, and the second hardware performs the processes of steps S10, S12, S16, S18, S22, and S24. It can be realized by executing. In this case, the first hardware executes the process of step S14 on condition that a signal indicating that an affirmative determination is made in the process of step S12 is received from the second hardware. Further, the first hardware receives the signal that the affirmative determination is made in step S18 from the second hardware, thereby executing the process of step S20 and receiving the signal that the affirmative determination is made in step S24. Under the condition, the engine 30 is driven.

  DESCRIPTION OF SYMBOLS 10 ... Power split mechanism, 12, 14 ... Motor generator, 16 ... Drive wheel, 18, 20 ... Inverter, 22 ... SMR, 24 ... Battery, 26 ... Charger, 28 ... Commercial power supply, 30 ... Engine, 32 ... Engine body 34 ... Oil pan, 40 ... Strainer, 40a ... Suction port, 42 ... Mesh member, 50 ... Electric oil pump, 50a ... Electric motor, 54 ... Oil control valve, 60 ... Control device, 62 ... CPU, 64 ... Memory, 70 ... power switch, 72 ... rotational speed sensor, 74 ... oil temperature sensor, 76 ... pressure sensor.

Claims (1)

An oil pan, a strainer having a suction port immersed in engine oil in the oil pan and provided with a mesh member for removing foreign matter in the engine oil, and the mesh member and engine in a distribution path of engine oil An electric oil pump that is provided between the main body and discharges the engine oil sucked from the suction port to the engine main body side, is a control target,
A freezing determination processing unit that determines that the water in the engine oil is frozen based on the temperature of the engine oil being equal to or lower than a specified temperature;
When it is determined that the moisture is frozen by the freezing determination processing unit, the target rotation speed of the electric motor built in the electric oil pump is determined to be frozen by the freezing determination processing unit when the engine is driven. A low speed processing unit that drives the electric oil pump to lubricate the engine body while lowering compared to the case of lubricating the engine body when not done,
Whether the mesh member is clogged based on at least one of the pressure of the engine oil and the rotational speed of the electric motor on the side of the engine body relative to the electric oil pump when processing by the low speed processing unit is being performed. A clogging determination processing unit for determining;
When it is determined by the clogging determination processing unit that the clogging has occurred, the engine main body side fluid is rotated by the electric oil pump by rotating the electric motor at a rotation speed higher than a target rotation speed by the low speed processing unit. A lubrication control device for an engine, comprising: a reverse rotation processing unit that performs a process of sucking and discharging the oil to the oil pan side over a predetermined time.

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