JP2009299665A - Control device and control method for oil pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately inhibit the deterioration of durability caused by the abnormal rotation of an oil pump in the oil pump driven by a motor. <P>SOLUTION: An ECU controls the oil pump driven by the motor and circulating oil for cooling a differential gear. The ECU executes the feedback control of a current command value I of the motor to maintain the rotation speed of the oil pump at target rotation speed. The ECU detects an oil temperature TH (S102) if the oil pump is in operation (Yes in S100), and calculates a threshold I (1) corresponding to the oil temperature TH (S104), referring a map of the threshold I(1) set to a larger value as the oil temperature TH is lower. The ECU determines an air sucking abnormality of the air pump (S112) and stops the oil pump (S114) if a current command value I is smaller than a calculated threshold I(1) (Yes in S110). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to control of an oil pump, and more particularly to control of an electric oil pump that outputs cooling oil to a cooling target component mounted on a vehicle.

  2. Description of the Related Art Conventionally, there has been known an electric oil pump that supplies hydraulic oil to an operation target component or supplies cooling oil to a cooling target component by rotating an impeller by a motor. In an electric oil pump, when the ambient temperature is extremely low (for example, −40 ° C.), the viscosity resistance of the oil is so high that the electric motor cannot be driven or the rotation speed of the electric motor does not exceed a certain level. In some cases, sufficient oil may not be supplied to the target part. A technique for solving such a problem is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-142435.

  The device disclosed in Japanese Patent Application Laid-Open No. 2000-142435 is a power steering device for driving an oil pump by an electric motor to generate hydraulic pressure and assisting steering by the generated hydraulic pressure. The power steering device includes an oil temperature detection unit that detects an oil temperature, a current detection unit that detects a current flowing through the electric motor, and a storage unit that stores a threshold value of the current flowing through the electric motor as a function of the oil temperature; A determination unit that determines whether the current flowing through the electric motor detected by the current detection unit is equal to or greater than a threshold value obtained from the storage unit based on the oil temperature detected by the oil temperature detection unit; And a control unit that drives the electric motor at a high speed when it is determined that the value of the current flowing through the electric motor is equal to or greater than the threshold value obtained from the storage unit. The threshold value of the current stored in the storage unit is set higher as the oil temperature is higher and lower as the oil temperature is lower.

According to the power steering device disclosed in Japanese Patent Laid-Open No. 2000-142435, a threshold value of the current flowing through the electric motor is stored as a function of the oil temperature, and the current flowing through the electric motor is a threshold corresponding to the oil temperature. If it is determined that the value is greater than or equal to the value, the electric motor is driven at a high speed. The current threshold value is set higher as the oil temperature is higher and lower as the oil temperature is lower. As a result, when the oil temperature is low and the viscosity resistance of the hydraulic oil is high, the current threshold is set low, so that the electric motor can be driven at a high speed. Therefore, the oil temperature can be quickly raised, and the electric motor can be driven without any problem even at extremely low temperatures.
JP 2000-142435 A JP 2001-241382 A JP 2003-262264 A

  By the way, in the electric oil pump, when the oil temperature is low, the suction resistance of the oil pump increases due to the high viscosity resistance of the oil, and cavitation may occur in the oil pump. If the oil pump continues to rotate while cavitation occurs, the durability of the oil pump may be significantly reduced. However, the above-mentioned Japanese Patent Application Laid-Open No. 2000-142435 does not mention any technique for suppressing a decrease in durability due to such an abnormal rotation of the oil pump.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to appropriately suppress a decrease in durability due to abnormal rotation of the oil pump in an oil pump driven by a motor. A control device and a control method are provided.

  The control device according to the first invention controls an oil pump driven by a motor. This control device includes a control means for controlling a drive current supplied to the motor so as to maintain the rotation speed of the oil pump at a predetermined rotation speed, and a drive set so as to increase as the oil temperature decreases. With reference to storage means for storing first threshold value data of current in advance, oil temperature detection means for detecting oil temperature, and first threshold value data stored in the storage means, A calculating means for calculating a threshold value of the driving current corresponding to the oil temperature detected by the oil temperature detecting means, and the rotation of the oil pump when the driving current is smaller than the threshold value calculated by the calculating means. A determination means for determining that the oil pump is abnormal, and a stop for stopping the oil pump by stopping the control of the drive current by the control means when the determination means determines that the rotation of the oil pump is abnormal means Including the.

  In addition to the configuration of the first invention, the control device according to the second aspect of the present invention returns the control of the drive current by the control unit after a predetermined time has elapsed since the stop of the oil pump by the stop unit, Further included is a re-driving means for driving again.

  In the control device according to the third invention, in addition to the configuration of the first or second invention, the first threshold value data is the first rotation abnormality in which air and oil are mixed in the oil pump. It is data for determining. The storage means stores, in addition to the first threshold data, the second threshold data of the driving current set to a value lower than the first threshold data without the oil pump sucking oil. It is stored in advance as data for determining the second rotation abnormality that is idling. The calculating means refers to the first threshold value data and the second threshold value data stored in the storage means, and the first threshold value corresponding to the oil temperature detected by the oil temperature detecting means and A second threshold value is calculated. The determination means determines that the second rotation abnormality occurs when the drive current is smaller than the second threshold value, and determines that the drive current is larger than the second threshold value and smaller than the first threshold value. Is determined to be the first rotation abnormality. The stop means stops the oil pump when it is determined that the rotation abnormality is one of the first rotation abnormality and the second rotation abnormality.

  In the control device according to the fourth aspect of the invention, in addition to the configuration of any one of the first to third aspects, the oil pump supplies oil for cooling the cooling target component mounted on the vehicle, the cooling target component and the radiator. It is a pump that circulates between.

  In the control device according to the fifth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the cooling target component is a differential gear.

  The control methods according to the sixth to tenth inventions have the same requirements as the control devices according to the first to fifth inventions, respectively.

  According to the present invention, for example, when an abnormality occurs in the oil pump in a state where oil and air (including bubbles generated by cavitation) are mixed in the oil pump (hereinafter, also referred to as “air sucking abnormality”), Since the pump load decreases and the rotation speed of the oil pump increases from a predetermined rotation speed, the drive current is decreased so as to decrease the increase in the rotation speed and maintain the rotation speed at the predetermined rotation speed. As described above, when the air sucking abnormality occurs, the drive current is decreased. However, the drive current after the decrease is larger as the oil temperature is lower (as the oil viscosity resistance is larger). Therefore, the first threshold value data of the drive current set so as to become larger as the oil temperature becomes lower is stored in advance, and the drive corresponding to the oil temperature is referred to by referring to the first threshold value data. A current threshold value is calculated, and when the drive current is smaller than the threshold value calculated by the calculating means, it is determined that the oil pump rotation is abnormal. If it does in this way, abnormal rotation of an oil pump can be judged appropriately. When it is determined that the rotation is abnormal, the oil pump is stopped. Thereby, since the abnormal rotation of the oil pump is suppressed, a decrease in the durability of the oil pump can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, the cooling device provided with the control apparatus which concerns on this Embodiment is demonstrated. The cooling device cools a differential gear that transmits power from a power source (for example, an engine) of the vehicle to the left and right drive shafts 110. Note that the present invention can be applied even when the object to be cooled is a component (for example, an engine, a transmission, a transfer, or the like) that is different from the differential gear.

  This cooling device includes an oil tank 200 that stores oil for cooling, an oil cooler 400 that releases oil heat to the outside air to cool the oil, and an impeller 310 that is rotated by a motor 320 to rotate the oil tank 200 and the oil. An oil pump 300 that circulates oil between the cooler 400, a drive circuit 500 that drives the motor 320 by supplying current from the power storage device 600 to the motor 320, and a current that is supplied from the drive circuit 500 to the motor 320 ( ECU 8000 for controlling the drive current of motor 320.

  Oil tank 200 is provided in the lower part of gear unit 100 having a differential gear therein, and communicates with the inside of gear unit 100. The cooling oil in the oil tank 200 is scattered inside the gear unit 100 by the rotation of the differential gear body. The scattered oil absorbs heat generated by the rotation of the differential gear and returns to the oil tank 200 again by its own weight.

  The oil used for cooling the differential gear is generally oil having a very high viscosity at the same temperature as compared with engine oil, ATF (Automatic Transmission Fluid), brake fluid, and the like.

  The oil tank 200 and the oil pump 300 are communicated with each other through a circulation path 210A. The oil pump 300 and the oil cooler 400 are communicated with each other through a circulation path 210B. The oil cooler 400 and the oil tank 200 are communicated with each other through a circulation path 210C.

  When the motor 320 is driven by the drive circuit 500, the impeller 310 rotates. As a result, the oil stored in the oil tank 200 is sucked into the oil pump 300 via the circulation path 210A and discharged to the circulation path 210B. The oil discharged to the circulation path 210B is supplied to the oil cooler 400 and cooled. The oil cooled by the oil cooler 400 is returned again to the oil tank 200 via the circulation path 210C.

  The ECU 8000 is connected to an oil temperature sensor 802 and a rotation speed sensor 804 via a harness or the like. The oil temperature sensor 802 detects the oil temperature TH stored in the oil tank 200. The rotation speed sensor 804 detects the rotation speed (pump rotation speed) N of the motor 320. These sensors output a signal representing the detection result to ECU 8000.

  In such a cooling device, the control device according to the present embodiment appropriately determines the rotation abnormality of the oil pump 300 based on the drive current of the motor 320, and stops the rotation of the oil pump 300 when the rotation abnormality is determined. Thus, it is a feature that deterioration of the durability of the oil pump 300 is suppressed in advance.

  FIG. 2 shows a functional block diagram of ECU 8000 which is a vehicle control apparatus according to the present embodiment. ECU 8000 includes an input interface 8100, a calculation processing unit 8200, a storage unit 8300, and an output interface 8400.

  The input interface 8100 receives the oil temperature TH from the oil temperature sensor 802 and the pump rotation speed N from the rotation speed sensor 804, and transmits them to the arithmetic processing unit 8200.

  Various information, programs, threshold values, maps, and the like are stored in the storage unit 8300, and data is read from or stored in the arithmetic processing unit 8200 as necessary.

  Arithmetic processing unit 8200 includes a current command value calculation unit 8210, a threshold value calculation unit 8220, a state determination unit 8230, and a pump control unit 8240.

  Current command value calculation unit 8210 calculates a drive current command value (current command value) I of motor 320. At this time, the current command value calculation unit 8210 feedback-controls the current command value I so that the pump rotation speed N detected by the rotation speed sensor 804 becomes the target rotation speed Ntag. The target rotational speed Ntag is set, for example, to a rotational speed that can output the torque required of the motor 320 at the rated voltage.

  Threshold calculation unit 8220 calculates threshold I (1) and threshold I (2) with reference to the map shown in FIG. 3 in order to determine an abnormal rotation of the oil pump.

  Here, the threshold value I (1) and the threshold value I (2) will be described with reference to FIG. The threshold value I (1) is for determining an abnormality (air sucking abnormality) in which the oil pump 300 is rotating in a state where oil and air (including bubbles generated by cavitation) are mixed in the oil pump 300. Is a threshold value to be compared with the current command value I. The threshold value I (2) is a threshold value that is compared with the current command value I in order to determine a rotation abnormality (idling abnormality) in which the oil pump 300 rotates by sucking only air without sucking oil. is there.

  The threshold values I (1) and I (2) are mapped using the oil temperature TH as a parameter as shown in FIG.

  The threshold value I (1) map shown in FIG. 3 measures the drive current of the motor 320 at the time of air suction abnormality for each oil temperature, and uses the measured value as a threshold value for determining air suction abnormality. It is a map.

  As shown in FIG. 3, the threshold value I (1) is set to a value smaller than the value at the time of normal rotation of the current command value I (broken line in FIG. 3). This is because when the air suction abnormality occurs, the amount of oil passing through the oil pump 300 is lower than that during normal rotation, the load torque of the oil pump 300 is reduced, and the pump rotational speed N is increased due to the reduction in the load torque. This is because it is considered that the current command value I is reduced as a result of the feedback of the current command value I so as to be suppressed.

  Further, the threshold value I (1) is set to a larger value as the oil temperature TH is lower. The reason why the threshold value I (1) is set in this way is that when the air suction abnormality occurs, the oil pump 300 sucks not only air but also oil, so that the lower the oil temperature TH (the higher the oil viscosity resistance). As a result, the load torque of the oil pump 300 is increased, and the current command value I is feedback-controlled so as to suppress the decrease in the pump rotational speed N due to the increase of the load torque. As a result, the current command value I also has a low oil temperature TH. This is because the increase is considered.

  The threshold value I (2) map shown in FIG. 3 is mapped as a threshold value for determining the idling abnormality by measuring the driving current of the motor 320 at the time of idling abnormality for each oil temperature. It is a thing.

  As shown in FIG. 3, threshold value I (2) is smaller than threshold value I (1) and is set to a substantially constant value regardless of the value of oil temperature TH. This is because the oil is not sucked at the time of idling abnormality, so that the load torque of the oil pump 300 becomes the lowest and is not affected by the viscosity of the oil.

  Referring to FIG. 2 again, state determination unit 8230 compares threshold values I (1) and I (2) calculated by threshold calculation unit 8220 with current command value I, and provides oil pump 300. The state of is determined. Specifically, when the current command value I is smaller than the threshold value I (2), it is determined that the idling is abnormal, the current command value I is larger than the threshold value I (2), and the threshold value When the current command value I is larger than the threshold value I (1), it is determined that the oil pump 300 is “normal rotation”. To do. The value to be compared with the threshold values I (1) and I (2) is replaced with the current command value I, and the actual drive current value of the motor 320 (the output of the sensor that detects the actual drive current of the motor 320). Value).

  Pump control unit 8240 outputs a control signal including current command value I to drive circuit 500 via output interface 8400 when the determination result of state determination unit 8230 is “normal rotation”. As a result, a drive current corresponding to the current command value I is supplied from the drive circuit 500 to the motor 320.

  On the other hand, the pump control unit 8240 stops the rotation of the oil pump 300 when the determination result of the state determination unit 8230 is “air sucking abnormality” or “idling abnormality”. Specifically, the calculation of the current command value I by the current command value calculation unit 8210 is stopped, and the output of the control signal to the drive circuit 500 is stopped.

  Note that in this embodiment, the current command value calculation unit 8210, the threshold value calculation unit 8220, the state determination unit 8230, and the pump control unit 8240 are all calculated by the CPU that is the arithmetic processing unit 8200 as the storage unit 8300. Although it is assumed that the program functions as software, which is realized by executing the program stored in the program, it may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  With reference to FIG. 4, a control structure of a program executed when ECU 8000 serving as the control device according to the present embodiment calculates current command value I will be described. Note that this program is repeatedly executed at a predetermined cycle time.

  In step (hereinafter step is abbreviated as S) 10, ECU 8000 detects pump rotational speed N from rotational speed sensor 804.

  In S12, ECU 8000 determines whether pump rotational speed N is larger than target rotational speed Ntag. If pump rotation speed N is greater than target rotation speed Ntag (YES in S12), the process proceeds to S14. Otherwise (NO in S12), the process proceeds to S16.

  In S14, ECU 8000 decreases current command value I in accordance with absolute value | N−Ntag | of the difference between pump rotational speed N and target rotational speed Ntag.

  In S16, ECU 8000 increases current command value I in accordance with absolute value | N−Ntag | of the difference between pump rotational speed N and target rotational speed Ntag.

  By such feedback control, the motor 320 is supplied with a drive current calculated so as to maintain the pump rotational speed N at the target rotational speed Ntag.

  With reference to FIG. 5, a control structure of a program executed when ECU 8000 serving as the control device according to the present embodiment determines rotation abnormality of oil pump 300 will be described. Note that this program is repeatedly executed at a predetermined cycle time.

  In S100, ECU 8000 determines whether oil pump 300 is being driven or not. If oil pump 300 is being driven (YES in S100), the process proceeds to S102. Otherwise (NO in S100), this process ends.

  In S102, ECU 8000 detects oil temperature TH. At S104, ECU 8000 calculates threshold values I (1) and I (2) according to oil temperature TH with reference to the map shown in FIG.

  As described above, the threshold value I (1) is a threshold value for determining an air sucking abnormality, and the threshold value I (2) is a threshold value for determining an idling abnormality. As shown in FIG. 3, the threshold value I (1) is set to a larger value as the drive current during normal rotation is smaller and the oil temperature TH is lower, and the threshold value I (2) is set to the threshold value I. It is smaller than (1) and is set to a substantially constant value regardless of the value of the oil temperature TH.

  In S106, ECU 8000 determines whether or not current command value I is smaller than threshold value I (2). If current command value I is smaller than threshold value I (2) (YES in S106), the process proceeds to S108. Otherwise (NO in S106), the process proceeds to S110. In S108, ECU 8000 determines that the oil pump 300 is idling abnormally.

  In S110, ECU 8000 determines whether or not current command value I is larger than threshold value I (2) and smaller than threshold value I (1). If current command value I is larger than threshold value I (2) and smaller than threshold value I (1) (YES in S110), the process proceeds to S112. Otherwise (NO in S110), the process proceeds to S122. In S112, ECU 8000 determines that air suction abnormality of oil pump 300 has occurred. In S114, ECU 8000 stops oil pump 300.

  In S116, ECU 8000 calculates stop time T of oil pump 300. At this time, the ECU 8000 may calculate the stop time T to a different value depending on whether the idling abnormality is determined or the air sucking abnormality is determined. For example, when the idling abnormality is determined, the stop time T may be calculated to be longer than when the air sucking abnormality is determined. Further, the stop time T may be calculated based on the oil temperature TH. That is, when the oil temperature TH is low, it takes a long time to lower the viscosity resistance of the oil, and it is not necessary to rotate the oil pump 300 to cool the oil. Therefore, the stop time T may be set longer. Good. Further, the stop time T may be set to a predetermined time regardless of idling abnormality or air sucking abnormality.

  In S118, ECU 8000 determines whether stop time T has elapsed or not. When stop time T has elapsed (YES in S118), the process proceeds to S120. Otherwise (NO in S118), the process returns to S118 and waits until the stop time T elapses.

  In S120, ECU 8000 restarts oil pump 300. Thereafter, the process returns to S102 in order to determine whether or not the abnormality of the oil pump 300 has been recovered. In S122, ECU 8000 determines that oil pump 300 is rotating normally.

  An operation of oil pump 300 controlled by ECU 8000 serving as the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  Assume that the air suction abnormality of the oil pump 300 occurs when the oil temperature TH is low. When the air suction abnormality occurs, the load on oil pump 300 decreases and pump speed N becomes larger than target speed Ntag (YES in S12), so the difference between pump speed N and target speed Ntag The current command value I is reduced according to the absolute value | N−Ntag | (S14).

  On the other hand, the oil temperature TH is detected (S102), and threshold values I (1) and I (2) for determining the rotation abnormality of the oil pump 300 are calculated according to the oil temperature TH (S102), and the current command When value I is at least smaller than threshold value I (1) (NO in S106, YES in S110), it is determined that there is an abnormal air suction (S112), and oil pump 300 is stopped (S114). .

  Here, when the air suction is abnormal, the oil pump 300 sucks not only air but also oil, and the load torque of the oil pump 300 increases as the oil temperature TH decreases (the viscosity resistance of the oil increases). The current command value I also increases as the oil temperature TH is lower. Considering such a change in the current command value I with respect to the oil temperature TH, the threshold value I (1) is set so as to increase as the oil temperature TH decreases, as shown in FIG. . Therefore, the air suction abnormality of the oil pump 300 can be appropriately determined based on the value of the current command value I. As described above, the air suction abnormality is appropriately determined and the oil pump 300 is stopped, so that the abnormal rotation of the oil pump 300 can be appropriately suppressed. Therefore, a decrease in the durability of the oil pump 300 can be suppressed.

  Thereafter, when stop time T elapses (YES in S118), oil pump 300 is re-driven (S120), and the abnormality of rotation of oil pump 300 is determined again (S102, S104, S106, S108, etc.). Therefore, it can be determined whether or not the rotation abnormality of the oil pump 300 has been recovered.

  As described above, according to the control device according to the present embodiment, the threshold map for air suction abnormality determination that is set so as to increase as the oil temperature decreases is stored in advance. When the threshold value corresponding to the oil temperature is calculated with reference to the motor, and the motor drive current (which may be the current command value or the actual drive current value) is smaller than the calculated threshold value Then, it is determined that the air suction is abnormal and the oil pump is stopped. Thereby, the air suction abnormality of the oil pump can be appropriately determined, and a decrease in the durability of the oil pump can be suppressed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the cooling device provided with the control apparatus which concerns on embodiment of this invention. It is a functional block diagram of a control device concerning an embodiment of the invention. It is a figure which shows the threshold value memorize | stored of the control apparatus which concerns on embodiment of this invention. It is a flowchart (the 1) which shows the control structure of ECU which comprises the control apparatus which concerns on embodiment of this invention. It is a flowchart (the 2) which shows the control structure of ECU which comprises the control apparatus which concerns on embodiment of this invention.

Explanation of symbols

  100 gear unit, 110 drive shaft, 200 oil tank, 210A, 210B, 210C circulation path, 300 oil pump, 310 impeller, 320 motor, 400 oil cooler, 500 drive circuit, 600 power storage device, 802 oil temperature sensor, 804 rotation Number sensor, 8000 ECU, 8100 input interface, 8200 arithmetic processing unit, 8210 current command value calculation unit, 8220 value calculation unit, 8230 state determination unit, 8240 pump control unit, 8300 storage unit, 8400 output interface.

Claims (10)

A control device for an oil pump driven by a motor,
Control means for controlling the drive current supplied to the motor so as to maintain the rotational speed of the oil pump at a predetermined rotational speed;
Storage means for storing in advance the first threshold value data of the driving current set so as to become larger as the oil temperature is lower;
Oil temperature detecting means for detecting the oil temperature;
Calculating means for calculating a threshold value of the drive current corresponding to the oil temperature detected by the oil temperature detecting means with reference to the first threshold value data stored in the storage means;
Determination means for determining that the rotation of the oil pump is abnormal when the drive current is smaller than the threshold value calculated by the calculation means;
A stopping means for stopping control of the drive current by the control means and stopping the oil pump when the determination means determines that the rotation of the oil pump is abnormal. Control device.   The control device further includes a redrive means for returning the control of the drive current by the control means and driving the oil pump again after a predetermined time has elapsed after the oil pump is stopped by the stop means. The control apparatus of the oil pump of Claim 1 containing. The first threshold data is data for determining a first rotation abnormality in which air and oil are mixed in the oil pump,
In addition to the first threshold value data, the storage means stores the second threshold value data of the drive current set to a value lower than the first threshold value data. Store in advance as data for determining the second rotation abnormality that is idling without sucking oil,
The calculating means refers to the first threshold value data and the second threshold data stored in the storage means, and corresponds to the oil temperature detected by the oil temperature detecting means. Calculating a threshold value of 1 and the second threshold value;
The determination means determines that the second rotation abnormality occurs when the drive current is smaller than the second threshold, and the drive current is greater than the second threshold and the first When it is smaller than the threshold value, it is determined as the first rotation abnormality,
3. The oil pump control according to claim 1, wherein the stopping unit stops the oil pump when it is determined that the rotation abnormality is one of the first rotation abnormality and the second rotation abnormality. 4. apparatus.   The oil pump according to any one of claims 1 to 3, wherein the oil pump is a pump that circulates oil that cools a cooling target component mounted on a vehicle between the cooling target component and a radiator. Control device.   The oil pump control device according to claim 4, wherein the cooling target component is at least one of a differential gear, an engine, a transmission, and a transfer. A control method performed by a control device that controls an oil pump driven by a motor, wherein the control device sets first threshold data of the drive current that is set to a larger value as the oil temperature is lower Including a storage device for storing
A control step of controlling a drive current supplied to the motor so as to maintain the rotation speed of the oil pump at a predetermined rotation speed;
An oil temperature detecting step for detecting the oil temperature;
A calculation step of referring to the first threshold value data stored in the storage device and calculating a threshold value of the drive current corresponding to the oil temperature detected in the oil temperature detection step;
A determination step of determining that the rotation of the oil pump is abnormal when the drive current is smaller than the threshold value calculated in the calculation step;
An oil pump control method including a stop step of stopping the oil pump by stopping the control of the drive current in the control step when it is determined in the determination step that the rotation of the oil pump is abnormal .   The control method further includes a re-drive step of returning the control of the drive current by the control step and driving the oil pump again after a predetermined time has elapsed since the oil pump was stopped by the stop step. The method for controlling an oil pump according to claim 6. The first threshold data is data for determining a first rotation abnormality in which air and oil are mixed in the oil pump,
In the storage device, in addition to the first threshold data, second threshold data of the driving current set to a value lower than the first threshold data is stored in the oil pump. Is stored in advance as data for determining the second rotation abnormality that is idling without sucking oil,
The calculating step refers to the first threshold value data and the second threshold value data stored in the storage device, and corresponds to the oil temperature detected in the oil temperature detecting step. Calculating a threshold value of 1 and the second threshold value;
The determination step determines that the second rotation abnormality occurs when the drive current is smaller than the second threshold, and the drive current is greater than the second threshold and the first When it is smaller than the threshold value, it is determined as the first rotation abnormality,
The oil pump control according to claim 6 or 7, wherein the stopping step stops the oil pump when it is determined that one of the first rotation abnormality and the second rotation abnormality is a rotation abnormality. Method.   The oil pump according to any one of claims 6 to 8, wherein the oil pump is a pump that circulates oil that cools a cooling target component mounted on a vehicle between the cooling target component and a radiator. Control method.   The oil pump control method according to claim 9, wherein the cooling target component is at least one of a differential gear, an engine, a transmission, and a transfer.

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