Motor drive device and electric oil pump device

Abstract

The present invention provides a motor drive device and an electric oil pump device that can stably rotate a motor even in an extremely low temperature state. One form of the motor drive device is a motor drive device that drives a motor, including: a drive unit that outputs a drive signal for driving the motor to the motor; and a control unit that controls the duty cycle of the drive signal based on three control parameters: an initial duty cycle, a duty cycle increase speed, and a target duty cycle. The control unit has a normal control mode in which the three control parameters are respectively specified values, and an extremely low temperature control mode in which at least one of the three control parameters is a value smaller than that of the normal control mode.

Description

Technical Field

[0001] The invention relates to a motor driving device and an electric oil pump device. Background Art

[0002] A hybrid vehicle includes a mechanical oil pump disposed inside a transmission and an electric oil pump operable independently of the driving of the engine. In such a hybrid vehicle, when the engine is not driven, the electric oil pump supplies the transmission with necessary oil pressure.

[0003] Patent Document 1 discloses a control method for a motor drive device in an electric oil pump when the oil temperature of a transmission is in an extremely low temperature state below a predetermined reference temperature. The control method measures the oil temperature of the transmission, and when the oil temperature of the transmission is in an extremely low temperature state below a predetermined reference temperature, performs duty control so that the rotation speed of the electric oil pump becomes a target rotation speed, and after the duty control, performs feedback control for maintaining the target rotation speed.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2013-122310 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, at extremely low temperatures below -10°C, the viscosity of the oil becomes extremely high compared to that at normal temperatures. Therefore, in the motor drive device described in Patent Document 1, when duty control is performed in a state where the viscosity of the oil is high so that the rotation speed of the electric oil pump becomes the target rotation speed, the load torque of the motor increases, and as a result, the output current value output from the motor drive device to the motor increases. The motor drive device is provided with a fail-safe function, which stops supplying current to the motor when the output current value exceeds an upper limit value. Therefore, if the output current value of the motor drive device increases due to the high viscosity of the oil as described above, the fail-safe function takes effect, and there is a possibility that the motor cannot be driven and the necessary oil pressure cannot be supplied.

[0009] The present invention has been made in view of the above circumstances, and one object of the present invention is to provide a motor drive device and an electric oil pump device that can stably rotate a motor even in an extremely low temperature state.

[0010] [Technical means to solve the problem]

[0011] An embodiment of the motor driving device of the present invention is a motor driving device for driving a motor, comprising: a driving unit that outputs a driving signal for driving the motor to the motor; and a control unit that controls the duty cycle of the driving signal based on three control parameters, namely, an initial duty cycle, a duty cycle increase speed, and a target duty cycle. The control unit has a normal control mode in which the three control parameters are respectively specified values, and an extremely low temperature control mode in which at least one of the three control parameters is a value smaller than that of the normal control mode.

[0012] An embodiment of the electric oil pump device of the present invention includes: a motor having a shaft; a pump located on one axial side of the shaft and driven by the motor via the shaft to eject oil; and the motor drive device driving the motor.

[0013] [Effects of the Invention]

[0014] According to the embodiments of the present invention, it is possible to provide a motor drive device and an electric oil pump device that can stably rotate a motor even in an extremely low temperature state. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a circuit block diagram schematically showing an electric oil pump device including a motor drive device according to the present embodiment.

[0016] Figure 2 This is an explanatory diagram of three control parameters: initial duty ratio, duty ratio increase speed, and target duty ratio.

[0017] Figure 3 It is a diagram showing a first modified example of the motor drive device according to the present embodiment.

[0018] Figure 4 It is a diagram showing a second modified example of the motor drive device according to the present embodiment.

[0019] [Explanation of Symbols]

[0020] 10, 10A, 10B: Motor drive device

[0021] 11: Power circuit

[0022] 12: Inverter circuit (drive unit)

[0023] 13: Control Department

[0024] 14: Storage

[0025] 15: Temperature sensor (sensor)

[0026] 20: Motor

[0027] 30: Pump

[0028] 40: Electric oil pump

[0029] 100: Electric oil pump device

[0030] 200: Battery

[0031] 300: External temperature sensor

[0032] 400: Upper control device DETAILED DESCRIPTION

[0033] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

[0034] Figure 1 Schematically shows a circuit block diagram of an electric oil pump device 100 including a motor drive device 10 according to the present embodiment. Figure 1 As shown, the electric oil pump device 100 includes a motor drive device 10 and an electric oil pump 40. The electric oil pump 40 includes a motor 20 and a pump 30. The electric oil pump device 100 is a device that supplies oil to a transmission mounted in a hybrid vehicle, for example.

[0035] The motor drive device 10 is a device for driving the motor 20 of the electric oil pump 40. The motor 20 is, for example, a three-phase brushless direct current (DC) motor. The motor 20 has a shaft 21 rotatably supported and a position sensor 22 for detecting the rotational position of the shaft 21. Figure 1 Although not shown in the figure, the motor 20 has a stator including a U-phase coil, a V-phase coil, and a W-phase coil. The position sensor 22 detects the rotation position of the shaft 21 and outputs a shaft position signal PS indicating the detection result to the motor drive device 10. As the position sensor 22, for example, a Hall sensor, an encoder, or a resolver can be used.

[0036] The pump 30 is located on one side of the shaft 21 of the motor 20 in the axial direction, and is driven by the motor 20 via the shaft 21 to eject the oil F. The pump 30 has an oil suction port 31 and an oil ejection port 32. The oil F is sucked into the pump 30 from the oil suction port 31, and then ejected from the oil ejection port 32 to the transmission side (not shown). In this way, the electric oil pump 40 is formed by connecting the pump 30 to the motor 20.

[0037] The motor drive device 10 includes a power supply circuit 11, an inverter circuit 12 (drive unit), a control unit 13, and a storage unit 14. The motor drive device 10 is electrically connected to a motor 20, a battery 200 as an external power source, and an external temperature sensor 300. In addition, the battery 200 and the external temperature sensor 300 are not components of the electric oil pump device 100 of this embodiment. The external temperature sensor 300 detects the ambient temperature and outputs an ambient temperature signal TS indicating the ambient temperature to the motor drive device 10.

[0038] The power supply circuit 11 has a first input terminal 11 a , a second input terminal 11 b , a first output terminal 11 c , and a second output terminal 11 d .

[0039] The first input terminal 11a of the power supply circuit 11 is electrically connected to the positive terminal of the battery 200. The second input terminal 11b of the power supply circuit 11 is electrically connected to the negative terminal of the battery 200. The first output terminal 11c of the power supply circuit 11 is electrically connected to the first input terminal 12a of the inverter circuit 12. The second output terminal 11d of the power supply circuit 11 is electrically connected to the second input terminal 12b of the inverter circuit 12.

[0040] The power supply circuit 11 converts the DC voltage Vi input from the battery 200 into a DC voltage Vo having a voltage value required for driving the motor 20, and outputs it to the inverter circuit 12. The DC voltage Vi input from the battery 200 is a voltage applied between the first input terminal 11a and the second input terminal 11b. The DC voltage Vo output from the power supply circuit 11 is a voltage generated between the first output terminal 11c and the second output terminal 11d.

[0041] The power supply circuit 11 has the following failure protection function: the current value flowing through the inverter circuit 12, that is, the output current value output from the motor drive device 10 to the motor 20 is measured, and when the output current value exceeds the upper limit value, the voltage output to the inverter circuit 12 is stopped, thereby stopping the current supply to the motor 20 through the inverter circuit 12.

[0042] In addition, although Figure 1 Although not shown in the figure, the power supply circuit 11 also generates a power supply voltage required for operating the control unit 13 and the storage unit 14 , and outputs the generated power supply voltage to the control unit 13 and the storage unit 14 .

[0043] The inverter circuit 12 is a drive circuit that outputs a drive signal for driving the motor 20 to the motor 20. Specifically, the inverter circuit 12 outputs a pulse-width modulated drive signal DSu to a U-phase coil (not shown) of the motor 20. In addition, the inverter circuit 12 outputs a pulse-width modulated drive signal DSv to a V-phase coil (not shown) of the motor 20. Furthermore, the inverter circuit 12 outputs a pulse-width modulated drive signal DSw to a W-phase coil (not shown) of the motor 20.

[0044] The inverter circuit 12 includes a first input terminal 12 a , a second input terminal 12 b , a first switching element SW1 , a second switching element SW2 , a third switching element SW3 , a fourth switching element SW4 , a fifth switching element SW5 , and a sixth switching element SW6 .

[0045] The first input terminal 12a of the inverter circuit 12 is electrically connected to the first output terminal 11c of the power supply circuit 11. The second input terminal 12b of the inverter circuit 12 is electrically connected to the second output terminal 11d of the power supply circuit 11. The DC voltage Vo output from the power supply circuit 11 is applied between the first input terminal 12a and the second input terminal 12b.

[0046] The first switch element SW1 to the sixth switch element SW6 are, for example, high-power power transistors such as Metal Oxide Semiconductor-Field Effect Transistor (MOS-FET). The first switch element SW1 and the fourth switch element SW4 are connected in series. The second switch element SW2 and the fifth switch element SW5 are connected in series. The third switch element SW3 and the sixth switch element SW6 are connected in series.

[0047] One end of each of the first switch element SW1 , the second switch element SW2 , and the third switch element SW3 is electrically connected to the first input terminal 12 a , and one end of each of the fourth switch element SW4 , the fifth switch element SW5 , and the sixth switch element SW6 is electrically connected to the second input terminal 12 b .

[0048] The U-phase coil of the motor 20 is electrically connected between the first switching element SW1 and the fourth switching element SW4. The V-phase coil of the motor 20 is electrically connected between the second switching element SW2 and the fifth switching element SW5. The W-phase coil of the motor 20 is electrically connected between the third switching element SW3 and the sixth switching element SW6.

[0049] The on / off states of the first to sixth switching elements SW1 to SW6 are controlled by control signals input from the control unit 13 described later. By controlling the on / off states of the first to sixth switching elements SW1 to SW6, the duty ratios of the drive signals DSu, DSv, and DSw output from the inverter circuit 12 to the motor 20 are controlled. By controlling the duty ratios of the drive signals DSu, DSv, and DSw, the rotation speed of the motor 20 can be controlled.

[0050] The control unit 13 is electrically connected to the inverter circuit 12, the storage unit 14, the position sensor 22 of the motor 20, and the external temperature sensor 300, respectively. The control unit 13 generates a control signal for controlling the on / off state of the first switch element SW1 to the sixth switch element SW6 based on the shaft position signal PS input from the position sensor 22 and the ambient temperature signal TS input from the external temperature sensor 300, and outputs the generated control signal to each switch element. That is, the control unit 13 controls the duty cycle of the drive signal DSu, the drive signal DSv, and the drive signal DSw output from the inverter circuit 12 to the motor 20 by controlling the on / off state of the first switch element SW1 to the sixth switch element SW6. Thus, the control unit 13 can control the rotation speed of the motor 20.

[0051] Thus, in the present embodiment, the control unit 13 controls the motor 20 by pulse width modulation (PWM) control, and the PWM control controls the rotation speed of the motor 20 by changing the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw. Specifically, the control unit 13 can increase the rotation speed of the motor 20 by increasing the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw. On the other hand, the control unit 13 can reduce the rotation speed of the motor 20 by reducing the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw. Within the range of the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw adjusted by the control unit 13 of the present embodiment, the value of the duty ratio is proportional to the rotation speed of the motor 20, for example.

[0052] The details will be described later. The control unit 13 controls the duty ratios of the drive signal DSu, the drive signal DSv, and the drive signal DSw based on the three control parameters of the initial duty ratio, the duty ratio increase speed, and the target duty ratio. In addition, the control unit 13 has a normal control mode in which the three control parameters are respectively specified values, and an extremely low temperature control mode in which at least one of the three control parameters is a value smaller than that in the normal control mode.

[0053] In this embodiment, the control unit 13 determines whether the ambient temperature is below a threshold value based on an ambient temperature signal TS inputted from the outside, and switches to a normal control mode when the ambient temperature exceeds the threshold value, and switches to a very low temperature control mode when the ambient temperature is below the threshold value. The threshold value is, for example, -10°C.

[0054] Such a control unit 13 can be implemented by a microcomputer such as a central processing unit (CPU).

[0055] The storage unit 14 is a semiconductor memory having a read only memory (ROM) and a random access memory (RAM), etc. The storage unit 14 pre-stores three control parameters of an initial duty cycle X1, a duty cycle increase speed X2, and a target duty cycle X3 for a normal control mode, and pre-stores three control parameters of an initial duty cycle Y1, a duty cycle increase speed Y2, and a target duty cycle Y3 for a very low temperature control mode.

[0056] like Figure 2 As shown, in the storage unit 14 of the present embodiment, "10%" is stored as the initial duty cycle X1 for the normal control mode, and "20%" is stored as the target duty cycle X3 for the normal control mode. The duty cycle increase speed X2 for the normal control mode is expressed by the following formula (1). In addition, ΔT1 is the time from the initial duty cycle X1 to the target duty cycle X3.

[0057] X2=(X3-X1) / ΔT1…(1)

[0058] In addition, in the storage unit 14, "8%" is stored as the initial duty ratio Y1 for the extremely low temperature control mode, and "15%" is stored as the target duty ratio Y3 for the extremely low temperature control mode. The duty ratio increase rate Y2 for the extremely low temperature control mode is expressed by the following formula (2). In addition, ΔT2 is the time from the initial duty ratio Y1 to the target duty ratio Y3.

[0059] Y2=(Y3-Y1) / ΔT2…(2)

[0060] In this embodiment, the absolute value of the difference between the initial duty X1 and the target duty X3 in the normal control mode is 10%. In addition, the absolute value of the difference between the initial duty Y1 and the target duty Y3 in the extremely low temperature control mode is 7%.

[0061] As described above, in the extremely low temperature control mode of the present embodiment, the three control parameters, namely the initial duty cycle, the duty cycle increase speed, and the target duty cycle, are all smaller values ​​than those in the normal control mode. In addition, the absolute value of the difference between the initial duty cycle Y1 and the target duty cycle Y3 in the extremely low temperature control mode is smaller than the absolute value of the difference between the initial duty cycle X1 and the target duty cycle X3 in the normal control mode.

[0062] Next, the operation of the motor drive device 10 configured as described above will be described.

[0063] When the DC voltage Vi is input from the battery 200 to the motor drive device 10 , the power supply circuit 11 outputs the DC voltage Vo to the inverter circuit 12 , and outputs the power supply voltage to the control unit 13 and the storage unit 14 .

[0064] The control unit 13 is activated by receiving the power supply voltage supplied from the power supply circuit 11, and determines whether the ambient temperature is below the threshold value (-10°C) based on the ambient temperature signal TS input from the external temperature sensor 300. When the ambient temperature exceeds the threshold value, the control unit 13 enters the normal control mode and reads the initial duty ratio X1, the duty ratio increase speed X2, and the target duty ratio X3 for the normal control mode from the storage unit 14.

[0065] Then, the control unit 13 controls the on / off state of each switching element of the inverter circuit 12 based on the initial duty cycle X1, the duty cycle increase speed X2 and the target duty cycle X3 for the normal control mode, thereby controlling the duty cycle of the drive signal DSu, the drive signal DSv and the drive signal DSw output from the inverter circuit 12 to the motor 20. As a result, the duty cycle of the drive signal DSu, the drive signal DSv and the drive signal DSw output from the inverter circuit 12 to the motor 20 is changed to Figure 2 The control mode changes as shown in the normal control mode.

[0066] On the other hand, when the ambient temperature is below the threshold, the control unit 13 enters the extremely low temperature control mode and reads the initial duty ratio Y1 , the duty ratio increase speed Y2 , and the target duty ratio Y3 for the extremely low temperature control mode from the storage unit 14 .

[0067] Then, the control unit 13 controls the on / off state of each switching element of the inverter circuit 12 based on the initial duty ratio Y1, the duty ratio increase speed Y2 and the target duty ratio Y3 for the extremely low temperature control mode, thereby controlling the duty ratio of the drive signal DSu, the drive signal DSv and the drive signal DSw output from the inverter circuit 12 to the motor 20. As a result, the duty ratios of the drive signal DSu, the drive signal DSv and the drive signal DSw output from the inverter circuit 12 to the motor 20 are as follows. Figure 2 The temperature changes as shown in the very low temperature control mode.

[0068] Here, for example, in an extremely low temperature state of below -10°C, the viscosity of the oil F becomes extremely high compared to the normal temperature state. If the viscosity of the oil F becomes high, the viscous resistance received by the pump 30 from the oil F becomes large, and the torque of the motor 20 required to rotate the pump 30 increases. Therefore, in an extremely low temperature state, assuming that the duty ratios of the drive signal DSu, the drive signal DSv, and the drive signal DSw output from the inverter circuit 12 to the motor 20 are controlled based on the initial duty ratio X1, the duty ratio increase speed X2, and the target duty ratio X3 for the normal control mode determined based on the normal temperature state, that is, the state where the viscosity of the oil F is relatively low, the load torque of the motor 20 may increase extremely. As a result, the output current value output from the inverter circuit 12 to the motor 20 increases and may exceed the upper limit value of the output current value determined in advance. Since the output current value exceeds the upper limit value, the fail-safe function of the power supply circuit 11 is activated, and the motor 20 may not be driven.

[0069] On the other hand, in the present embodiment, the control unit 13 has a normal control mode and an extremely low temperature control mode, and in the extremely low temperature control mode, at least one of the three control parameters of the initial duty cycle, the duty cycle increase speed and the target duty cycle is a value smaller than that in the normal control mode. Therefore, in the extremely low temperature control mode, it is easy to reduce the duty cycle of each drive signal DSu, the drive signal DSv and the drive signal DSw compared with the normal control mode. The duty cycle of the drive signal DSu, the drive signal DSv and the drive signal DSw in the extremely low temperature control mode is easy to be smaller than that in the normal control mode, so by setting the control unit 13 to the extremely low temperature control mode, it is easy to reduce the rotation speed of the motor 20 compared with the normal control mode. When the rotation speed of the motor 20 decreases, the rotation speed of the pump 30 also decreases. Here, the viscous resistance is proportional to the speed, so the lower the rotation speed of the pump 30, the smaller the viscous resistance received from the oil F. Therefore, even in the case where the viscosity of the oil F is relatively high, the viscous resistance received by the pump 30 can be reduced, thereby suppressing the increase of the load torque of the motor 20. Therefore, for example, in an extremely low temperature state where the ambient temperature is -10°C or lower, by setting the control unit 13 to the extremely low temperature control mode, even when the viscosity of the oil F becomes relatively high, the load torque of the motor 20 can be suppressed from increasing, thereby suppressing the increase in the output current value output from the inverter circuit 12 to the motor 20. By suppressing the increase in the output current value, the fail-safe function of the power supply circuit 11 can be suppressed from being activated, thereby suppressing the situation where the motor 20 cannot be driven. Therefore, according to the present embodiment, the motor 20 can be stably rotated even in an extremely low temperature state, thereby supplying oil pressure.

[0070] In this embodiment, the three control parameters of the initial duty cycle, the duty cycle increase speed and the target duty cycle are prepared for a normal control mode and an extremely low temperature control mode, and the control parameters can be selected according to the ambient temperature.

[0071] Specifically, in the present embodiment, the control unit 13 determines whether the ambient temperature is below a threshold value based on an ambient temperature signal TS input from the outside, and switches to a normal control mode when the ambient temperature exceeds the threshold value, and switches to an extremely low temperature control mode when the ambient temperature is below the threshold value. Therefore, when the ambient temperature is relatively high and the viscosity of the oil F is relatively low, the rotation speed of the motor 20 can be appropriately increased by the normal control mode, and the oil F can be appropriately delivered by the pump 30. On the other hand, when the ambient temperature is relatively low and the viscosity of the oil F is relatively high, the rotation speed of the motor 20 can be suppressed by the extremely low temperature control mode, thereby suppressing the increase in the load torque of the motor 20. In this way, in the present embodiment, by switching between the normal control mode and the extremely low temperature control mode according to the ambient temperature, the increase in the load torque, that is, the increase in the output current value, can be suppressed even in an extremely low temperature state, and smooth and stable motor control can be achieved without stopping the rotation of the motor 20.

[0072] In this embodiment, in the extremely low temperature control mode, the three control parameters of the initial duty cycle, the duty cycle increase speed and the target duty cycle are all smaller than those in the normal control mode. Figure 2 As shown, assuming that each mode is started at the same time, the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw in the extremely low temperature control mode can be made smaller than the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw in the normal control mode at any time. By making the duty ratio of the drive signal DSu, the drive signal DSv, and the drive signal DSw in the extremely low temperature control mode smaller than that in the normal control mode, the rotation speed of the motor 20 can be made smaller than when the motor 20 is controlled by the normal control mode during the entire period of controlling the motor 20 by the extremely low temperature control mode. Therefore, the increase in the load torque of the motor 20 can be more appropriately suppressed.

[0073] Specifically, in the present embodiment, when the ambient temperature is higher than -10°C, the duty ratios of the drive signals DSu, DSv, and DSw output from the inverter circuit 12 to the motor 20 are controlled based on the initial duty ratio X1, the duty ratio increase speed X2, and the target duty ratio X3 for the normal control mode determined on the premise that the viscosity of the oil F is relatively low. On the other hand, when the ambient temperature is lower than -10°C, the duty ratios of the drive signals DSu, DSv, and DSw output from the inverter circuit 12 to the motor 20 are controlled based on the initial duty ratio Y1, the duty ratio increase speed Y2, and the target duty ratio Y3 for the extremely low temperature control mode determined on the premise that the viscosity of the oil F is relatively high.

[0074] In addition, in the above embodiment, the case where all three control parameters for the extremely low temperature control mode are smaller than those for the normal control mode is exemplified, but as long as at least one of the three control parameters for the extremely low temperature control mode is smaller than that for the normal control mode, the effect of suppressing the increase of the load torque (i.e., the increase of the output current value) can be obtained. However, in order to maximize the above effect, it is preferred that all three control parameters for the extremely low temperature control mode are smaller than those for the normal control mode.

[0075] For example, you can also Figure 2 As shown in the single-point chain line shown, the initial duty cycle Y1 for the extremely low temperature control mode is set to the same value (10%) as that of the normal control mode, and the duty cycle increase speed Y2 and the target duty cycle Y3 (17%) are set to values ​​smaller than those of the normal control mode. Alternatively, in the extremely low temperature control mode, the initial duty cycle and the target duty cycle of the three control parameters may be smaller values ​​than those of the normal control mode. In the above case, the effect of suppressing the increase of the load torque, that is, suppressing the increase of the output current value, can also be obtained.

[0076] In the embodiment, the absolute value of the difference between the initial duty cycle Y1 and the target duty cycle Y3 in the extremely low temperature control mode is smaller than the absolute value of the difference between the initial duty cycle X1 and the target duty cycle X3 in the normal control mode. As a result, the duty cycle difference of the drive signal from the time when the motor 20 is driven to the end of the rotation can be further reduced. As a result, the effect of further suppressing the increase of the output current value in the extremely low temperature control mode can be obtained compared with the increase of the output current value in the normal control mode.

[0077] [Modifications]

[0078] The present invention is not limited to the above-described embodiments, and each configuration described in this specification can be appropriately combined within a range that does not contradict each other.

[0079] For example, in the above-described embodiment, the configuration in which the information on the ambient temperature is supplied from the external temperature sensor 300 to the control unit 13 of the motor drive device 10 is exemplified. Figure 3 As in the motor drive device 10A shown in the figure, the motor drive device further includes a temperature sensor 15.

[0080] The temperature sensor 15 detects the ambient temperature and outputs an ambient temperature signal TS indicating the ambient temperature to the control unit 13. As the temperature sensor 15, any sensor can be used as long as it can output a signal having a correlation with the ambient temperature. In this case, the control unit 13 determines whether the ambient temperature is below a threshold value based on the ambient temperature signal TS input from the temperature sensor 15, and switches to a normal control mode when the ambient temperature exceeds the threshold value, and switches to an extremely low temperature control mode when the ambient temperature is below the threshold value.

[0081] By adopting such a configuration, all operations including temperature detection can be completed by the motor drive device itself.

[0082] In addition, you can Figure 4 As shown in the motor drive device 10B, a configuration is adopted in which the control mode is switched according to the operation command signal DS input from the external upper control device 400. In the above case, when the duty ratio of the operation command signal DS input from the upper control device 400 is included in the first range, the control unit 13 switches to the normal control mode, and when the duty ratio of the operation command signal DS is included in the second range, the control unit 13 switches to the extremely low temperature control mode.

[0083] By adopting such a configuration, it is not necessary to grasp the ambient temperature on the motor drive device side, so that the device cost can be reduced, and the weight and size of the motor drive device can be reduced.

Claims

1. An electric oil pump device, comprising: a motor having a shaft; a pump, located on one axial side of the shaft and driven by the motor via the shaft to spray oil; a driving unit, outputting a driving signal for driving the motor to the motor; as well as The control unit controls the duty cycle of the driving signal based on three control parameters: an initial duty cycle, a duty cycle increase speed, and a target duty cycle. The control unit has a normal control mode in which the three control parameters are respectively set to predetermined values, and an extremely low temperature control mode in which the motor rotates stably in an extremely low temperature state, and at least the target duty ratio in the extremely low temperature control mode is a value smaller than the target duty ratio in the normal control mode. The target duty ratio in the normal control mode is greater than the initial duty ratio in the normal control mode, The target duty ratio in the extremely low temperature control mode is greater than the initial duty ratio in the extremely low temperature control mode.

2. The electric oil pump device according to claim 1, wherein: The control unit determines whether the ambient temperature is below a threshold value based on an ambient temperature signal input from the outside, and switches to the normal control mode when the ambient temperature exceeds the threshold value, and switches to the extremely low temperature control mode when the ambient temperature is below the threshold value.

3. The electric oil pump device according to claim 1, further comprising a sensor, wherein the sensor detects an ambient temperature and outputs an ambient temperature signal indicating the ambient temperature to the control unit. The control unit determines whether the ambient temperature is below a threshold based on the ambient temperature signal input from the sensor, and switches to the normal control mode when the ambient temperature exceeds the threshold, and switches to the extremely low temperature control mode when the ambient temperature is below the threshold.

4. The electric oil pump device according to claim 1, wherein: When the duty ratio of the work command signal input from the outside is included in the first range, the control unit switches to the normal control mode, and when the duty ratio of the work command signal is included in the second range, the control unit switches to the extremely low temperature control mode.

5. The electric oil pump device according to any one of claims 1 to 4, wherein: In the extremely low temperature control mode, both the initial duty ratio and the target duty ratio of the three control parameters are smaller values ​​than those in the normal control mode.

6. The electric oil pump device according to any one of claims 1 to 4, wherein: In the extremely low temperature control mode, all of the three control parameters are smaller values ​​than those in the normal control mode.

7. The electric oil pump device according to any one of claims 1 to 4, wherein: An absolute value of a difference between the initial duty ratio and the target duty ratio in the extremely low temperature control mode is smaller than an absolute value of a difference between the initial duty ratio and the target duty ratio in the normal control mode.

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