JP2013213458A - Electric oil pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric oil pump capable of discharging oil at a desired discharge oil pressure irrespective of usage.SOLUTION: An electric oil pump includes: a pump body 10 feeding oil; a motor 20 driving the pump body 10; and a pump ECU 40 controlling a discharge oil pressure of the oil fed by the pump body 10 by controlling an electric current supplied to the motor 20 and rotation speed of the motor 20. The pump ECU 40 performs at least one of a change for reducing the electric current supplied to the motor 20 and a change for reducing the rotation speed of the motor 20, as an integrated number of rotations of the pump body 10 detected by a rotation sensor 25 is increased.

Description

  The present invention relates to an electric oil pump driven by a motor.

  As shown in Patent Document 1, a vehicle equipped with CVT (Continuously Variable Transmission) includes an electric oil pump in order to realize an idling stop function. In such a vehicle, while idling is stopped, the mechanical pump driven by the engine is stopped, but the electric oil pump supplies the necessary minimum hydraulic pressure (hereinafter abbreviated as necessary hydraulic pressure) to the CVT. Rapid recurrence is possible.

  Such an electric oil pump includes an outer rotor in which inner teeth formed with a trochoid curve are formed on the inner periphery, an inner rotor formed with outer teeth that are formed with a trochoid curve and mesh with the inner teeth, Generally, it is composed of a trochoid pump composed of a housing for rotatably housing the outer rotor and the inner rotor, and a motor for rotating the inner rotor. The required hydraulic pressure is controlled by controlling the current supplied to the motor and the rotational speed of the motor.

  In the electric oil pump described above, the discharge hydraulic pressure of the oil discharged by the electric oil pump is obtained by referring to the mapping data representing the relationship between the electric current, the rotation speed, and the hydraulic pressure with respect to the detected motor consumption current and the rotation speed of the motor. Is estimated. Based on the estimated discharge hydraulic pressure, the current supplied to the motor and the rotation speed of the motor are controlled so that the hydraulic pressure of the oil discharged from the electric oil pump becomes the required hydraulic pressure.

JP 2001-227606 A

  However, in the above-described electric oil pump, the sliding resistance of the sliding parts constituting the electric oil pump, that is, the inner rotor, the outer rotor, and the casing, decreases due to wear. As a result, it is estimated that the current consumption of the motor is reduced and the discharge hydraulic pressure is reduced. As a result, control to increase the current supplied to the motor and the rotation speed of the motor is performed, and more oil than necessary is supplied to the CVT. As a result, electric energy is wasted and noise generated by the electric oil pump is increased.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an electric oil pump capable of discharging oil of a desired discharge hydraulic pressure regardless of the amount of use.

  (Claim 1) A pump body that feeds oil, a motor that drives the pump body, a current supplied to the motor, and a rotational speed of the motor, thereby controlling the oil that the pump body feeds. An electric oil pump having a control unit for controlling the discharge hydraulic pressure, and having a usage amount detection unit for detecting a usage amount of the pump body, wherein the control unit detects the pump detected by the usage amount detection unit. Based on the usage amount of the main body, at least one of the current supplied to the motor and the rotational speed of the motor is changed.

  (Claim 2) It is preferable that the control unit performs at least one of a change for reducing the current supplied to the motor and a change for reducing the rotation speed of the motor as the amount of use of the pump body increases.

  (Claim 3) The control unit refers to the current consumption of the motor and the rotation speed of the motor by referring to the mapping data representing the relationship between the current consumption and the rotation speed and the discharge hydraulic pressure of the pump body. When the discharge hydraulic pressure of the pump body is estimated, the motor is controlled based on the estimated discharge hydraulic pressure, and the usage amount of the pump main body detected by the usage amount detection unit reaches a specified usage amount, the less motor It is preferable to change to mapping data in which the same discharge hydraulic pressure as that of the mapping data is estimated with less current consumption or a smaller number of rotations of the motor.

  (Claim 4) It is preferable that the usage amount detection unit detects an integrated value of the rotation speed of the pump body as a usage amount of the pump body.

(Claim 5)
It is preferable that the usage amount detection unit detects an integrated value of the driving time of the pump body as a usage amount of the pump body.

  (Claim 1) According to the electric oil pump of the present invention, the control unit changes the current supplied to the motor and the rotation speed of the motor based on the usage amount of the pump body detected by the usage amount detection unit. As a result, when the control unit increases the amount of use of the pump main body and the sliding resistance of the pump main body decreases, the control unit performs a change that decreases the current supplied to the motor or decreases the rotation speed of the motor. In addition, it is possible to reduce the discharge hydraulic pressure corresponding to the decrease in the sliding resistance of the pump body, and to supply the oil with the appropriate discharge hydraulic pressure. For this reason, the electric oil pump which can discharge the oil of desired discharge hydraulic pressure irrespective of the usage-amount can be provided.

  (Claim 2) The controller performs a change to reduce the current supplied to the motor or a change to reduce the rotation speed of the motor as the amount of use of the pump body increases. As a result, the discharge hydraulic pressure corresponding to the decrease in the sliding resistance of the pump body can be surely reduced, so that the electric oil pump can supply oil with an appropriate discharge hydraulic pressure.

  (Claim 3) When the use amount of the pump body detected by the use amount detection unit reaches the specified use amount, the control unit is the same as the mapping data before the change with less motor current consumption or less motor rotation speed. The mapping data is changed to the estimated discharge hydraulic pressure. As a result, a decrease in the motor current consumption and an increase in the rotation speed of the motor accompanying a decrease in the sliding resistance of the pump body are corrected, and an appropriate discharge hydraulic pressure is estimated. For this reason, an increase in the discharge hydraulic pressure due to the excessive estimation of the discharge hydraulic pressure is prevented, and as a result, the electric oil pump can supply oil with an appropriate discharge hydraulic pressure.

  (Claim 4) The usage amount detection unit detects the integrated value of the rotational speed of the pump body as the usage amount of the pump body. Accumulated rotational speed of pump body and wear amount of sliding parts of pump body are proportional, and wear amount of sliding parts of pump body and reduction of sliding resistance of pump body are proportional, so it is more accurate It is possible to detect a decrease in sliding resistance of the pump body. For this reason, the electric oil pump is capable of supplying oil with an appropriate discharge hydraulic pressure with higher accuracy.

  (Claim 5) The usage amount detection unit detects the integrated value of the driving time of the pump body as the usage amount of the pump body. As a result, the amount of use of the pump body is calculated simply by integrating the drive time of the pump body, so the processing burden associated with the calculation of the amount of use of the pump body is reduced.

It is a schematic diagram of a vehicle in which the electric oil pump of this embodiment is mounted. It is AA sectional drawing of FIG. It is a flowchart of the hydraulic control process performed by pump ECU shown in FIG. 2 is a table showing estimated hydraulic pressure mapping data in an initial state used when the pump ECU shown in FIG. 1 calculates an estimated hydraulic pressure. 6 is a graph showing estimated hydraulic pressure mapping data in the initial state shown in FIG. It is a flowchart of the estimated hydraulic pressure correction process of 1st Embodiment performed by pump ECU shown in FIG. 4 is a table showing changed estimated hydraulic pressure mapping data used when the pump ECU shown in FIG. 1 calculates an estimated hydraulic pressure. It is the graph showing the estimated hydraulic pressure mapping data after the change shown in FIG. (A) It is the graph showing the characteristic of the conventional electric oil pump. (B) It is the graph showing the characteristic of the electric oil pump of this embodiment. It is a flowchart of the estimated hydraulic pressure correction process of 2nd Embodiment performed by pump ECU shown in FIG.

(Vehicle overview)
Hereinafter, an embodiment of an electric oil pump according to the present invention will be described with reference to the drawings. First, a vehicle 500 on which the electric oil pump 100 of the present invention is mounted will be described with reference to FIG. The vehicle 500 includes an engine 200, a CVT 300, a vehicle ECU 400, and an electric oil pump 100. In the present embodiment, the vehicle 500 has an idling stop function in which the engine 200 stops when the vehicle stops and the engine 200 starts when the vehicle restarts. The engine 200 is a gasoline engine, a diesel engine, or the like that uses a hydrocarbon fuel such as gasoline or light oil, and outputs a rotational driving force to the CVT 300.

  The CVT 300 decelerates the rotational driving force input from the engine 200 at a predetermined gear ratio and outputs it to the differential. A drive wheel is rotationally coupled to the differential via a drive shaft or the like. The CVT 300 can change the gear ratio steplessly. In the present embodiment, the driving pulley that receives the rotational driving force from the engine 200, the driven pulley that outputs the rotational driving force to the differential, and the driving side A belt type CVT having a belt wound around a pulley and a driven pulley. The CVT 300 changes the gear ratio and adjusts the belt tension by controlling the hydraulic pressure in the hydraulic chamber 301 provided in each pulley. The CVT 300 is provided with a mechanical pump 302 that is driven by the rotational driving force of the engine 200 and supplies oil of a predetermined hydraulic pressure to the hydraulic chamber 301. When the engine 200 is activated, the machine Oil of a predetermined hydraulic pressure is supplied to the hydraulic chamber 301 by the type pump 302. The hydraulic chamber 301 of the CVT 300 is provided with a temperature sensor 303 that detects the oil temperature of the oil flowing through the hydraulic chamber 301.

  Vehicle ECU 400 performs overall control of vehicle 500 and controls engine 200 and CVT 300. Note that “oil temperature information” of oil flowing through the hydraulic chamber 301 detected by the temperature sensor 303 is input to the vehicle ECU 400, and the vehicle ECU 400 outputs the “oil temperature information” to the pump ECU 40.

  Note that the vehicle ECU 400 stops the engine 200 when it is determined that the running vehicle 500 stops and meets the conditions after the idling stop based on the vehicle speed information detected by a vehicle speed sensor (not shown). A “pump start command” is output to the pump ECU 40. Furthermore, the vehicle ECU 400 determines whether the brake pedal is released or the accelerator is released in the vehicle 500 being stopped based on the brake information detected by a brake sensor (not shown) or the accelerator opening information detected by an accelerator opening sensor (not shown). When it is determined that the idling stop cancellation condition such as being stepped on is satisfied, the engine 200 is started and a “pump start command” is output to the pump ECU 40.

(Electric oil pump)
The electric oil pump 100 includes a pump body 10, a motor 20, a motor driver 30, and a pump ECU 40. The pump body 10 is driven by the motor 20 and supplies oil of a predetermined hydraulic pressure in the hydraulic chamber 301 of the CVT 300 while idling is stopped (when the engine 200 is stopped). The pump body 10 will be described in detail later.

  The motor 20 outputs a rotational driving force to the pump body 10. In this embodiment, the motor 20 is a direct current brushless motor, and is a stator 22 fixed to the casing 21 and configured by a coil, and a rotor 23 that is rotatably provided on the inner peripheral side of the stator 22 and is configured by a permanent magnet. And a rotating shaft 24 of the rotor 23. Further, the motor 20 is provided with a rotation sensor 25 for detecting the rotation speed of the motor 20 (rotation speed of the rotor 23) and detecting the rotation speed of the motor 20. The “motor rotation speed”, which is the rotation speed of the motor 20 detected by the rotation sensor 25, is input to the pump ECU 40.

  The motor driver 30 is connected to a vehicle battery (not shown) and supplies current to the stator 22 of the motor 20 based on a control signal from the pump ECU 40. The vehicle 500 includes a motor current detection unit 31 such as an ammeter that detects a “motor current” that is a current value of a current supplied from the motor driver 30 to the motor 20. The “motor current” detected by the motor current detector 31 is input to the pump ECU 40.

  The pump ECU 40 is communicably connected to the vehicle ECU 400 and the motor driver 30, and outputs a control signal to the motor driver 30 based on a command from the vehicle ECU 400. Specifically, as will be described later, the pump ECU 40 controls the discharge hydraulic pressure of the oil supplied by the pump body 10 by controlling the current supplied to the motor 20 and the rotational speed of the motor 20.

  The pump ECU 40 includes a microcomputer, and the microcomputer includes an input / output interface, a CPU, a RAM, and a “storage unit” such as a ROM and a nonvolatile memory, which are connected via a bus. The CPU executes a program corresponding to the flowcharts shown in FIGS. The RAM temporarily stores variables necessary for executing the program. The “storage unit” stores the program, a program for executing the flows shown in FIGS. 3, 6, and 10, and estimated hydraulic pressure mapping data shown in FIGS. The control by the pump ECU 40 will be described in detail later.

  Below, the structure of the pump main body 10 is demonstrated using FIG. As shown in FIG. 2, the pump body 10 includes a casing 11, an inner rotor 12, and an outer rotor 13. The casing 11 is made of a lightweight aluminum alloy or the like, and the inner rotor 12 and the outer rotor 13 are made of cast iron or the like having excellent wear resistance.

  The casing 11 has a block shape, and an outer storage portion 11b, which is a flat cylindrical space, is formed therein. As shown in FIG. 1, an insertion hole 11 a that communicates with the outer storage portion 11 b is formed in the center of the casing 11. The rotating shaft 24 of the motor 20 is inserted through the insertion hole 11a. As shown in FIGS. 1 and 2, the casing 11 is formed with a suction port 11c and a discharge port 11d communicating with the outer storage portion 11b. As shown in FIG. 1, the suction port 11 c is connected to an oil reservoir 304 formed at the bottom of the CVT 300 by a suction pipe 91. Further, the discharge port 11d is connected to the hydraulic chamber 301 of the CVT 300 by a discharge pipe 92.

  As shown in FIG. 2, the outer rotor 13 is rotatably mounted in the outer storage portion 11b. The outer rotor 13 is a flat cylindrical shape having a circular cross section, and an inner tooth 13a that is a space is formed at the center. An inner rotor 12 is rotatably disposed in the inner teeth 13a. The inner rotor 12 has a ring shape, and outer teeth 12a are formed on the outer edge. The inner teeth 13a and the outer teeth 12a are constituted by a plurality of trochoid curves. The number of teeth of the external teeth 12a is smaller than the number of teeth of the internal teeth 13a. The outer teeth 12a and the inner teeth 13a mesh with each other. The rotation center of the outer rotor 13 is eccentric with respect to the rotation center of the inner rotor 12.

  An inner spline 12 b is formed at the center of the inner rotor 12. The inner spline 12 b is spline-fitted with an outer spline 24 a formed at the end of the rotating shaft 24 of the motor 20. With such a structure, the inner rotor 12 is rotated by the motor 20.

  When the motor 20 rotates, the inner rotor 12 rotates, and the outer rotor 13 meshed with the outer teeth 12a by the inner teeth 13a also rotates. Then, the space formed between the external teeth 12a and the internal teeth 13a sequentially moves from the suction port 11c to the discharge port 11d, and oil is supplied from the suction port 11c to the discharge port 11d. Then, oil is supplied from the oil reservoir 304 of the CVT 300 to the suction port 11c through the suction pipe 91, and the oil is pumped from the discharge port 11d to the hydraulic chamber 301 of the CVT 300 through the discharge pipe 92.

(Control executed by pump ECU)
Next, control executed by the pump ECU 40 will be described. The pump ECU 40 to which the “pump start command” is input outputs a control signal to the motor driver 30 to rotate the motor 20 and start pumping oil to the hydraulic chamber 301 of the CVT 300 by the pump body 10 ( Start of electric oil pump 100). On the other hand, the pump ECU 40 to which the “pump stop command” is input outputs a control signal to the motor driver 30 to stop the motor 20 and pump the oil to the hydraulic chamber 301 of the CVT 300 by the pump body 10. Stop (stop of electric oil pump 100).

  Next, the “hydraulic pressure control process” executed by the pump ECU 40 will be described with reference to FIG. As described above, when the electric oil pump 100 is started, in S11, the pump ECU 40 acquires the “motor current” (consumption current) from the motor driver 30 and the “motor rotation speed” from the rotation sensor 25. Acquire and advance the program to S12.

  In S12, the pump ECU 40 calculates the “estimated hydraulic pressure” of the hydraulic chamber 301 of the CVT 300 based on the acquired “motor current” and “motor rotational speed”. Specifically, the pump ECU 40 calculates the “motor rotation speed” (for example, rpm (rotation per minute)) of the motor 20 from the “motor rotation speed”. Next, the pump ECU 40 determines the detected “motor current” and “motor rotational speed” as “estimated hydraulic pressure” representing the relationship between the “motor current” and “motor rotational speed” and the “estimated hydraulic pressure” shown in FIG. “Estimated oil pressure” is obtained by referring to “mapping data”. When S12 ends, the program proceeds to S13.

  In S13, the pump ECU 40 acquires “oil temperature information”, and corrects the “estimated oil pressure” calculated in S12 based on the acquired “oil temperature information” in S14. Specifically, the pump ECU 40 corrects the “estimated oil pressure” by multiplying the “estimated oil pressure” calculated in S12 by a coefficient corresponding to the “oil temperature information”, and the corrected “estimated oil pressure”. Is calculated. When S14 ends, the program proceeds to S15.

  In S15, the pump ECU 40 compares the “estimated hydraulic pressure” with the “target hydraulic pressure”. As shown in FIG. 5, the “target hydraulic pressure” is larger than a “necessary hydraulic pressure” (for example, 220 kPa) which is a minimum hydraulic pressure of the hydraulic chamber 301 necessary for restarting the CVT 300, and is a predetermined level. It is a hydraulic pressure (for example, 300 to 330 kPa) having a pressure range. The electric oil pump 100 discharges oil to the hydraulic chamber 301 so that the hydraulic chamber 301 becomes the “target hydraulic pressure”. If the pump ECU 40 determines that the “estimated oil pressure” is smaller than the “target oil pressure”, the program proceeds to S16. If the pump ECU 40 determines that the “estimated oil pressure” is greater than the “target oil pressure”, the program proceeds to S17. If it is determined that the “estimated oil pressure” is within the “target oil pressure” range, the program is returned to S11. When the program returns from S15 to S11, the current supplied to the motor 20 and the rotation speed of the motor 20 are maintained, and the “discharge hydraulic pressure” of the oil that is currently being supplied by the pump body 10 is maintained. (Output of electric oil pump 100) is maintained.

  In S <b> 16, the pump ECU 40 outputs a control signal to the motor driver 30 so that the “discharge hydraulic pressure” of the pump body 10 increases. Specifically, the pump ECU 40 outputs a control signal for increasing at least one of the current supplied to the motor 20 and the rotational speed of the motor 20 to the motor driver 30. When S16 ends, the program returns to S11.

  In S <b> 17, the pump ECU 40 outputs a control signal to the motor driver 30 so that the “discharge hydraulic pressure” of the pump body 10 decreases. Specifically, the pump ECU 40 outputs a control signal for reducing at least one of the current supplied to the motor 20 and the rotational speed of the motor 20 to the motor driver 30. When S17 ends, the program returns to S11.

(Estimated hydraulic pressure correction process of the first embodiment)
Next, the “estimated hydraulic pressure correction process of the first embodiment” will be described using the flow shown in FIG. When the vehicle 500 is ready to travel, in S31, the pump ECU 40 obtains the “motor rotational speed”, integrates the “motor rotational speed”, and calculates the “integrated rotational speed” of the pump body 10. . In the present embodiment, the inner rotor 12 constituting the pump body 10 is directly connected to the rotating shaft 24 of the motor 20. For this reason, the rotational speed of the motor 20 and the rotational speed of the inner rotor 12, that is, the rotational speed of the pump body 10 are the same. Further, the “accumulated rotational speed” is held even after the key is removed from the vehicle 500. When S31 ends, the program proceeds to S32.

  In S32, when the pump ECU 40 determines that the “integrated rotational speed” has reached the maximum specified rotational speed (for example, several tens of millions) (S32: YES), “the estimated hydraulic pressure correction process of the first embodiment” ”Is terminated, and if it is determined that“ integrated rotation speed ”has not reached the maximum specified rotation speed (S32: NO), the program proceeds to S33.

  In S33, when the pump ECU 40 determines that the “accumulated rotational speed” has reached a specified rotational speed (for example, several million times) (S33: YES), the program proceeds to S34, and the “integrated rotational speed” is If it is determined that the specified rotational speed has not been reached (S33: NO), the program is returned to S31.

  In S34, the pump ECU 40 changes the “estimated hydraulic pressure mapping data change” in the initial state shown in FIG. 4 to the “estimated hydraulic pressure mapping data” shown in FIG. The “estimated hydraulic pressure mapping data” shown in FIG. 7 has the same “discharge hydraulic pressure” as the “estimated hydraulic pressure mapping data” (shown in FIG. 4) before the change, with less current consumption of the motor 20 or less rotational speed of the motor 20. ”Is estimated mapping data, and as will be described later, even if there is a decrease in the current consumption of the motor 20 or an increase in the rotation speed of the motor 20 due to a decrease in the sliding resistance of the pump body 10, The mapping data is mapped so that the “estimated hydraulic pressure” is calculated. When S34 ends, the program proceeds to S35.

  In S35, the pump ECU 40 resets the “integrated rotation speed” to 0 and returns the program to S31. Thus, every time the “integrated rotation speed” of the pump body 10 reaches the specified rotation speed, the pump body 10 is changed to appropriate “estimated hydraulic pressure mapping data”.

(Comparison between comparative example and this embodiment)
Hereinafter, a comparison between a conventional electric oil pump as a comparative example and the electric oil pump 100 of the present embodiment will be described with reference to FIGS. In the conventional electric oil pump, the sliding resistance of the sliding parts constituting the electric oil pump, that is, the inner rotor 12, the outer rotor 13, and the casing 11, decreases with use. Since the electric oil pump is controlled so that the rotation speed of the motor 20 is constant, if the sliding resistance of the sliding parts constituting the electric oil pump is reduced, the current consumption of the motor 20 is reduced. For example, if the consumption current of the motor 20 is reduced from 6.18A ((1) in FIG. 4) to 5.56A ((2) in FIG. 4), the “discharge hydraulic pressure” is reduced from 325 kPa to 277 kPa. Presumed. Then, as shown in (2) of FIG. 5, it is determined that the “discharge hydraulic pressure” is smaller than the “target hydraulic pressure”. Then, the pump ECU performs control to increase the rotational speed of the motor 20 and the current supplied by the motor 20 in order to change the reduced “discharge hydraulic pressure” to the “target hydraulic pressure” (shown in (3) of FIGS. ).

  Thus, in the prior art, as the accumulated rotational speed (usage amount) of the pump body 10 increases and the sliding resistance of the pump body 10 decreases, the “discharge hydraulic pressure” increases as shown in FIG. Continuedly, the “discharge hydraulic pressure” becomes excessive with respect to the required hydraulic pressure. In addition, the noise generated by the electric oil pump continues to increase.

  On the other hand, in the electric oil pump 100 of the present embodiment, as described above, when the accumulated rotation speed of the pump body 10 reaches the specified rotation speed (S33: YES in FIG. 6), the “estimated hydraulic pressure mapping data” is changed. (S34 in FIG. 6). For this reason, with the use of the electric oil pump 100, the sliding resistance of the inner rotor 12, the outer rotor 13, and the casing 11 which are sliding parts constituting the electric oil pump 100 is reduced, and the current consumption of the motor 20 is reduced. Even if it decreases, the “estimated oil pressure mapping data” in the initial state shown in FIG. 4 is changed to the “estimated oil pressure mapping data” shown in FIG. 7, so that “discharge oil pressure” is properly estimated ((( 4) As shown in FIG. 8, it is estimated that “discharge hydraulic pressure” is within the range of “target hydraulic pressure” (shown in FIG. 8 (4)).

  In this way, every time the “integrated rotation speed” of the pump body 10 reaches the specified rotation speed, the pump body 10 is changed to appropriate “estimated hydraulic pressure mapping data”, so that as shown in FIG. Even if the accumulated rotational speed (usage amount) increases, the “discharge hydraulic pressure” cannot continue to increase, and the “discharge hydraulic pressure” does not become excessive with respect to the “necessary hydraulic pressure”. Further, the noise generated by the electric oil pump 100 does not continue to increase.

  In the above description, the present embodiment has been described by exemplifying a case where the current consumption of the motor 20 is reduced as the sliding resistance of the pump body 10 is reduced. However, even when the rotational speed of the motor 20 increases with a decrease in the sliding resistance of the pump body 10 or when the rotational speed of the motor 20 increases in addition to the decrease in the current consumption of the motor 20, By using the “estimated oil pressure mapping data” after the change (shown in FIG. 7), an appropriate “estimated oil pressure” can be calculated.

  As shown in FIG. 9A, the increase in “discharge hydraulic pressure” and the increase in noise accompanying the driving of the pump body 10 become constant when the predetermined “integrated rotation speed” is reached. For this reason, in S32 shown in FIG. 6, when the pump ECU 40 determines that the “integrated rotation speed” has reached the maximum specified rotation speed, the “estimated hydraulic pressure correction process of the first embodiment” is terminated. I have to.

(Estimated hydraulic pressure correction process of the second embodiment)
Next, the difference between the “estimated hydraulic pressure correction process of the second embodiment” and the above-described embodiment will be described using the flow shown in FIG. When the vehicle 500 is ready to travel, in S41, the pump ECU 40 obtains the time during which the motor 20 is driving the pump body 10, accumulates the time, and calculates the “integrated drive time” of the pump body 10. calculate. This “integrated driving time” is held even after the key is removed from the vehicle 500. When S41 ends, the program proceeds to S42.

  In S42, when the pump ECU 40 determines that the “integrated drive time” has reached the maximum specified drive time (for example, tens of thousands of hours) (S42: YES), “the estimated hydraulic pressure correction process of the second embodiment” When it is determined that the “integrated drive time” has not reached the maximum specified drive time (S42: NO), the program proceeds to S43.

  In S43, when the pump ECU 40 determines that the “integrated drive time” has reached a specified drive time (for example, several hundred hours) (S43: YES), the program proceeds to S44, and the “integrated drive time” is specified. If it is determined that the drive time has not been reached (S43: NO), the program is returned to S41.

  In S44, the pump ECU 40 changes from the “estimated oil pressure mapping data change” in the initial state shown in FIG. 4 to “estimated oil pressure mapping data” shown in FIG. 7, and the program proceeds to S45.

  In S45, the pump ECU 40 resets the “integrated drive time” to 0 and returns the program to S41. As described above, in the “estimated hydraulic pressure correction process of the second embodiment”, whenever the “integrated drive time” of the pump body 10 reaches the specified drive time, it is changed to appropriate “estimated hydraulic pressure mapping data”. For this reason, as shown in FIG. 9B, even if the cumulative drive time (usage amount) of the pump body 10 increases and the sliding resistance of the pump body 10 decreases, the “discharge hydraulic pressure” continues to increase. Therefore, the “discharge hydraulic pressure” does not become excessive with respect to the required hydraulic pressure. Further, the noise generated by the electric oil pump 100 does not continue to increase.

  As shown in FIG. 9A, the increase in “discharge hydraulic pressure” and the increase in noise accompanying the driving of the pump body 10 are constant when a predetermined “integrated drive time” is reached. Therefore, when the pump ECU 40 determines in S42 shown in FIG. 10 that the “integrated drive time” has reached the maximum specified drive time, the “estimated hydraulic pressure correction process of the second embodiment” is terminated. I have to.

(Effect of this embodiment)
As described above in detail, according to the electric oil pump 100 according to the present embodiment, the pump ECU 40 (control unit) uses the pump body 10 usage amount detected by the rotation sensor 25 or the pump ECU 40 (usage amount detection unit). The current supplied to the motor 20 and the rotation speed of the motor 20 are changed based on (“integrated rotation speed”, “integrated drive time”). As a result, the pump ECU 40 decreases the current supplied to the motor 20 or decreases the rotational speed of the motor 20 as the amount of use of the pump body 10 increases and the sliding resistance of the pump body 10 decreases. Further, it is possible to reduce the “discharge hydraulic pressure” corresponding to the increase associated with the decrease in the sliding resistance of the pump main body 10 and to supply the appropriate “discharge hydraulic pressure” oil. Therefore, it is possible to provide the electric oil pump 100 that can discharge oil having a desired “discharge hydraulic pressure” regardless of the amount of use.

  Further, the pump ECU 40 (control unit) performs a change to decrease the current supplied to the motor 20 or a change to decrease the rotation speed of the motor 20 as the amount of use of the pump body 10 increases. As a result, the “discharge hydraulic pressure” corresponding to the decrease in the sliding resistance of the pump body 10 can be surely reduced, so that the electric oil pump 100 supplies the oil with the appropriate “discharge hydraulic pressure”. Can do.

  In addition, the pump ECU 40 (control unit) is configured so that the usage amount (“integrated rotational speed”, “integrated driving time”) of the pump main body 10 detected by the rotation sensor 25 or the pump ECU 40 (usage amount detection unit) 6 (YES in S33 of FIG. 6, YES in S43 of FIG. 10), the current consumption of the smaller motor 20 or the smaller motor 20 is reduced in S34 of FIG. 6 or S44 of FIG. The mapping data (shown in FIG. 7) is changed to the same “discharge hydraulic pressure” as the mapping data before the change (shown in FIG. 4) at the rotational speed. As a result, the decrease in the current consumption of the motor 20 and the increase in the rotation speed of the motor 20 due to the decrease in the sliding resistance of the pump body 10 are corrected, and an appropriate “discharge hydraulic pressure” is estimated. For this reason, an increase in the “discharge hydraulic pressure” due to the excessive estimation of the “discharge hydraulic pressure” is prevented, and as a result, the electric oil pump 100 can supply the oil of the appropriate “discharge hydraulic pressure”. .

  In addition, in the “estimated hydraulic pressure correction process of the first embodiment” shown in FIG. 6, the rotation sensor 25 (use amount detection unit) detects the integrated value of the rotation speed of the pump body 10 as the use amount of the pump body 10. . The accumulated rotational speed of the pump body 10 and the wear amount of the sliding parts (inner rotor 12, outer rotor 13, casing 11) of the pump body 10 are proportional to each other, and the wear amount of the sliding parts of the pump body 10 and the pump body 10 are proportional to each other. Therefore, the decrease in the sliding resistance of the pump body 10 can be detected with higher accuracy. For this reason, the electric oil pump 100 can supply the oil of the appropriate “discharge hydraulic pressure” with higher accuracy.

  Further, in the “estimated hydraulic pressure correction process of the second embodiment” shown in FIG. 10, the pump ECU 40 (usage amount detection unit) detects the integrated value of the drive time of the pump body 10 as the amount of use of the pump body 10. As a result, the pump ECU 40 calculates the amount of use of the pump body 10 only by accumulating the drive time of the pump body 10, so the processing burden associated with the calculation of the amount of use of the pump body 10 is reduced.

  In the embodiment described above, the pump ECU 40 determines that the appropriate “estimated hydraulic pressure mapping data” is used when the usage amount of the pump main body 10 (“integrated rotation speed”, “integrated use drive time”) or a specified value is reached. , The motor 20 is controlled so that the “discharge hydraulic pressure” becomes the “target hydraulic pressure” by appropriately estimating the “discharge hydraulic pressure” of the pump body 10. However, the pump ECU 40 performs at least one of a change to reduce the current supplied to the motor 20 and a change to reduce the rotation speed of the motor 20 as the usage amount of the pump main body 10 increases, so that the discharge hydraulic pressure is the target hydraulic pressure. There is no problem even if it becomes.

  In the embodiment described above, the pump body 10 driven by the motor 20 is a trochoid pump. However, the pump body 10 is not limited to a trochoid pump, and may be a volumetric pump that applies pressure to oil with rotating parts such as a gear pump. The gear pump has a structure in which gears meshing with each other are provided in parallel so as to be rotatable in the housing, and the inner peripheral surface of the housing is formed along the outer periphery of the gear. In this gear pump, when the gears that mesh with each other rotate, the space between the gear and the housing sequentially moves from the suction port formed in the housing to the discharge port side, and liquid is fed from the suction port 11c to the discharge port 11d. The

  In the embodiment described above, the motor 20 is a DC brushless motor, but may be a DC brush motor or an AC motor.

  In the embodiment described above, the “motor current” is detected by the motor current detector 31. However, the motor driver 30 and the pump ECU 40 may be embodiments that detect “motor current”. In the embodiment described above, the “motor rotation speed” is detected by the rotation sensor 25 that detects the rotation speed of the motor 20. However, the motor driver 30 or the pump ECU 40 may be an embodiment that detects the “motor rotational speed”.

DESCRIPTION OF SYMBOLS 11 ... Pump main body, 20 ... Motor, 25 ... Rotation sensor (use amount detection part), 31 ... Motor current detection part 40 ... Pump ECU (control part, use amount detection part)
100 ... Electric oil pump

Claims (5)

By controlling the pump main body for supplying oil, the motor for driving the pump main body, the current supplied to the motor and the rotational speed of the motor, the oil discharge hydraulic pressure of the oil supplied by the pump main body is controlled. An electric oil pump having a control unit,
A usage amount detection unit for detecting the usage amount of the pump body;
The said control part is an electric oil pump which changes at least one of the electric current supplied to the said motor, and the rotational speed of the said motor based on the usage-amount of the said pump main body which the said usage-amount detection part detected.   2. The electric oil pump according to claim 1, wherein the control unit performs at least one of a change to reduce a current supplied to the motor and a change to reduce the rotation speed of the motor as the amount of use of the pump body increases. The controller is
Estimating the discharge hydraulic pressure of the pump body by referring to the mapping data representing the relationship between the current consumption and rotation speed and the discharge hydraulic pressure of the pump body, the current consumption of the motor and the rotation speed of the motor, Controlling the motor based on the estimated discharge hydraulic pressure,
When the usage amount of the pump body detected by the usage amount detection unit reaches a specified usage amount, the same discharge hydraulic pressure as the mapping data is estimated with a smaller current consumption of the motor or a smaller rotational speed of the motor. The electric oil pump according to claim 2, wherein the electric oil pump is changed to mapping data.   The electric oil pump according to any one of claims 1 to 3, wherein the usage amount detection unit detects an integrated value of the rotation speed of the pump body as a usage amount of the pump body.   The electric oil pump according to any one of claims 1 to 3, wherein the usage amount detection unit detects an integrated value of a driving time of the pump body as a usage amount of the pump body.

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