JP6088170B2 - Control device for electric oil pump for vehicle - Google Patents

Description

  The present invention relates to a control device that outputs an operation amount to an electric oil pump for a vehicle based on a detected value of an oil temperature.

Patent Document 1 discloses a motor control device that limits a motor current based on a maximum value among integrated values of respective phase currents of a three-phase DC brushless motor.
In Patent Document 2, a temperature estimation value is obtained from the heat generation amount of the motor based on the supply current, and the heat dissipation amount based on the difference between the integrated value of the heat generation amount and the ambient temperature, and the current upper limit value is set according to the temperature estimation value. Thus, an overheat protection device that restricts energization of the motor is disclosed.

JP 2002-238293 A JP 2011-098625 A

  By the way, when a unit for setting a target value and a unit for outputting an operation amount based on the target value while performing current limitation are individually provided (in the case of being configured by individual computers), both are temperature sensors. In order to be able to use the detection results of the two, each unit has a temperature sensor and either inputs a temperature detection signal directly, or a wire (harness) for transmitting a target value signal. In addition, it is necessary to provide an electric wire (harness) for transmitting the temperature detection value, resulting in an increase in cost and a deterioration in device layout.

  The present invention has been made in view of the above problems, and an object thereof is to enable an electric oil pump to be controlled with high accuracy based on a detected value of an oil temperature while suppressing an increase in cost and a deterioration in layout. .

Therefore, the present invention is a unit that outputs a control target value of an electric oil pump for a vehicle, wherein the first unit that outputs a detected value of oil temperature during a stop period of the electric oil pump, and the first unit includes: A second unit that inputs the control target value to be output and the detected value of the oil temperature and outputs an operation amount of the electric oil pump, and the second unit is an electric motor that drives the electric oil pump. The amount of operation of the electric oil pump so that the current does not exceed the current upper limit value according to the detected value of the oil temperature input during the stop period of the electric oil pump and the elapsed time since starting the electric oil pump. To be restricted.

  According to the above invention, the detected value of the oil temperature can be used in both the first unit and the second unit, and the target value and the detected value of the oil temperature are transmitted using a single electric wire (harness). This makes it possible to control the electric oil pump with high accuracy based on the detected value of the oil temperature while suppressing an increase in cost and deterioration in layout.

1 is a block diagram of a transmission system in an embodiment of the present invention. It is a block diagram which shows the function of the main computer and pump drive computer in embodiment of this invention. It is a figure which shows the example of a characteristic of the pulse signal SIG transmitted toward the pump drive computer from the main computer in embodiment of this invention. It is a figure which shows the example of a characteristic of the pulse signal SIG transmitted toward the pump drive computer from the main computer in embodiment of this invention. It is a flowchart which shows the electric current limiting process in the pump drive computer in embodiment of this invention. It is a figure which shows the correlation with the oil temperature and current limiting offset time in embodiment of this invention. It is a figure which shows the correlation with the current limiting timer and limiting current in embodiment of this invention. It is a flowchart which shows the output process of the pulse signal STATE in the pump drive computer in embodiment of this invention. It is a figure which shows the example of a characteristic of the pulse signal STATE transmitted toward the main computer from the pump drive computer in embodiment of this invention. It is a figure which shows the example of a characteristic of the pulse signal STATE transmitted toward the main computer from the pump drive computer in embodiment of this invention. It is a block diagram which shows in detail the function of the main computer in embodiment of this invention. It is a flowchart which shows the outline | summary of the process of the main computer in embodiment of this invention. It is a flowchart which shows the process at the time of normal rotation in the main computer in embodiment of this invention. It is a flowchart which shows the process at the time of the current limitation in the main computer in embodiment of this invention. It is a flowchart which shows the process at the time of the failure in the main computer in embodiment of this invention.

Embodiments of the present invention will be described below.
FIG. 1 shows an application example to a vehicle transmission as an example of a control device for an electric oil pump for a vehicle.
In FIG. 1, a transmission 1 is a mechanism for decelerating the output rotation of an engine (internal combustion engine). A vehicle on which the engine is mounted includes, for example, a motor together with the engine, and stops the engine when the vehicle stops or starts. It is a hybrid vehicle.

The electric oil pump 2 sucks up oil from an oil pan (not shown) of the transmission 1 and supplies the oil to the lubrication and cooling system of the transmission 1.
The electric oil pump 2 is a fluid pump that rotationally drives a pump unit 22 such as a vane pump by an electric motor 21 such as a three-phase DC brushless motor.
Energization of the electric motor 21 is adjusted by the drive circuit 3, and the drive circuit 3 operates according to the operation amount output from the pump drive computer (second unit) 4.

Further, the pump drive computer 4 calculates the operation amount based on the target value output from the main computer (first unit) 5 and the control amount.
The target value is, for example, a target motor rotation speed (rpm), a target motor current, and the like, and the control amount is an actual motor rotation speed (rpm), an actual motor current, and the like. It has a function to detect.

  The pump drive computer 4 and the main computer 5 include a first signal line SL1 (first harness) for transmitting a target value from the main computer 5 to the pump drive computer 4, and the pump drive computer 4 to the main computer 5. The second signal line SL2 (second harness) for transmitting the pump rotation speed, failure information, and the like is electrically connected.

FIG. 2 is a block diagram showing functions of the pump drive computer 4 and the main computer 5.
The target value calculation unit 51 of the main computer 5 inputs signals from various sensors that detect the driving conditions of the vehicle, and based on these signals, the rotational speed rpm of the electric motor 21 that drives the electric oil pump 2 (or The target value of the motor current is calculated, and a signal SIG indicating the target value is transmitted to the pump drive computer 4 side via the first signal line SL1.

The signals input by the target value calculation unit 51 are, for example, an operation command for the electric oil pump 2, a brake signal, an accelerator opening signal, a shift position signal, an oil temperature signal TF, a battery voltage signal, a vehicle body tilt signal, and a clutch transmission. There are a torque signal, a clutch slip rotation speed signal, and the like.
The clutch is a power transmission clutch included in the transmission 1, and when the fastening force of the clutch is controlled by oil supplied from the electric oil pump 2, the target value calculation unit 51 is configured as described above. Input clutch transmission torque signal, clutch slip rotation speed signal, etc.

As shown in FIG. 1, an oil temperature sensor (oil temperature detecting means) 6 for detecting the oil temperature TF (° C.) in the oil pan of the transmission 1 is provided, and the output of the oil temperature sensor 6 is the main computer. 5 to the target value calculation unit 51.
In addition to the target value calculation unit 51, the main computer 5 includes a rotation speed / failure information determination unit 52, a rotation speed calculation unit 53, and a diagnosis / protection control unit 54.

The rotational speed information / failure information determination unit 52 receives the rotational speed information and the failure information from the pump drive computer 4 via the second signal line (second harness) SL2.
Then, the rotation speed / failure information determination section 52 sends the rotation speed information to the rotation speed calculation section 53, and the rotation speed calculation section 53 calculates the motor rotation speed (rpm). Further, the rotation speed / failure information determination unit 52 sends failure information to the diagnosis / protection control unit 54, and the diagnosis / protection control unit 54 executes diagnosis of presence / absence of failure, fail-safe control according to the diagnosis result, and the like. To do.

On the other hand, the pump drive computer 4 includes a motor operation amount calculation unit 41, a motor rotation number calculation unit 42, a motor current detection unit 43, a self-diagnosis unit 44, a rotation number / failure information transmission unit 45, and the like.
The motor rotation speed calculation unit 42 receives a pulse signal output from a rotation sensor provided in the electric motor 21 and measures the frequency of the pulse signal, thereby rotating the rotation speed (rpm of the electric motor 21 (electric oil pump 2)). ) Is output to the motor operation amount calculation unit 41 and the rotation number / failure information transmission unit 45.

The motor current detection unit 43 detects the current (A) flowing through the electric motor 21 and outputs information on the motor current to the motor operation amount calculation unit 41 and the self-diagnosis unit 44.
The motor operation amount calculation unit 41 detects the target value (target motor rotation number or target motor current) calculated by the main computer 5, the motor rotation number detected by the motor rotation number calculation unit 42, and the motor current detection unit 43. The motor current is input, and the operation amount of the electric motor 21 is calculated based on these, and output to the drive circuit 3.
The operation amount of the electric motor 21 is, for example, a duty ratio in duty control.

The motor operation amount calculation unit 41 performs feedback control in which the duty ratio is changed so that the control amount (motor rotation speed or motor current or the like) approaches a target value (target motor rotation speed or target motor current).
For example, if the target value is the target motor rotation number, the motor operation amount calculation unit 41 causes the actual motor rotation number (rpm) detected by the motor rotation number calculation unit 42 to approach the target motor rotation number (rpm). The duty ratio of the drive signal output to the drive circuit 3 is changed according to the deviation between the target motor speed and the actual motor speed.

In addition, the motor operation amount calculation unit 41 has a function of limiting the increase in the duty ratio so that the motor current falls below the current upper limit value in preference to the motor control that brings the control amount close to the target value.
Further, the target value calculation unit 51 of the main computer 5 sets the target value of the electric motor 21 to the motor of the pump drive computer 4 via the first signal line SL1 during the operation period of the electric motor 21 (electric oil pump 2). Although it outputs to the operation amount calculating part 41, in the stop period of the electric motor 21, it replaces with target value and the signal of oil temperature TF (oil temperature detection value) is similarly sent to the pump drive computer 4 via the first signal line SL1. To the motor operation amount calculation unit 41.

The motor operation amount calculation unit 41 sets a current upper limit value based on the oil temperature TF, and increases the operation amount (duty ratio) of the electric motor 21 so that the actual motor current does not exceed the current upper limit value. Limit.
The current upper limit value corresponding to the oil temperature TF is a temperature at which the temperature of the electric motor 21 or the drive circuit 3 exceeds the thermal life limit (allowable maximum temperature) even if the electric motor 21 is continuously driven with the current of the current upper limit value. The current value is set based on experiments and simulations in advance.

Transmission of the target value and the oil temperature TF from the target value calculation unit 51 of the main computer 5 to the motor operation amount calculation unit 41 of the pump drive computer 4 is performed by, for example, PWM communication according to the target value and the oil temperature TF. Is called.
As an example of the PWM communication described above, as shown in FIGS. 3A and 3B, a pulse signal SIG transmitted from the target value calculation unit 51 to the motor operation amount calculation unit 41 via the first signal line SL1. And the duty ratio D of the pulse signal SIG can be changed according to the target value and the oil temperature TF.

The motor operation amount calculation unit 41 that receives the pulse signal SIG detects the duty ratio D of the transmitted pulse signal SIG, and uses the detected duty ratio D as a target value (target motor speed) using a conversion table or the like. , Target motor current) or oil temperature TF, the target value and oil temperature TF instructed by the target value calculation unit 51 are determined.
Here, whether the duty ratio indicates the target value or the oil temperature TF can be determined by changing the fixed value of the frequency f of the pulse signal SIG.

That is, as shown in FIG. 3A, the target value calculation unit 51 fixes the frequency f of the pulse signal SIG to f1 and sets the duty ratio D of the pulse signal SIG to the target value when transmitting the target value. Change according to. Further, when transmitting the oil temperature TF, the target value calculation unit 511 fixes the frequency f of the pulse signal SIG to f2 (f1 ≠ f2) as shown in FIG. The duty ratio D is changed according to the oil temperature TF.
The motor operation amount calculation unit 41 that receives the pulse signal SIG measures the frequency f of the pulse signal SIG. If the measured frequency f is f1, the target value is transmitted and the duty ratio is If it is determined that the difference in D indicates the target value and the measured frequency f is f2, it is determined that the oil temperature TF is transmitted and the difference in the duty ratio D indicates the oil temperature TF. To do.

In other words, the pulse signal SIG having the frequency f of f2 has the duty ratio D indicating the oil temperature TF and also serves as a stop command for the electric motor 21, and the motor operation amount calculator 531 has the frequency f of While the pulse signal SIG that is f2 is being input, that is, when the target value is not input, the energization to the electric motor 21 is interrupted and the drive is stopped.
When the frequency f of the pulse signal SIG is switched from f2 to f1, it is regarded as a drive command for the electric motor 21, and the target value is determined from the duty ratio D of the pulse signal SIG so that the control amount approaches the target value. In addition, the duty ratio of the drive signal sent to the drive circuit 3 of the electric motor 21 is changed.

In the example shown in FIGS. 3A and 3B, the frequency f of the pulse signal SIG is fixed, and the duty ratio D is changed according to the target value and the oil temperature TF. As shown in (B), the duty ratio D of the pulse signal SIG can be fixed, and the frequency f can be changed according to the target value and the oil temperature TF.
When the duty ratio D of the pulse signal SIG is fixed, the fixed value of the duty ratio D is made different depending on which of the target value and the oil temperature TF is transmitted. That is, when transmitting the target value, as shown in FIG. 4A, the duty ratio D is fixed to D1, and the frequency f is changed according to the target value. On the other hand, when transmitting the oil temperature TF, as shown in FIG. 4B, the duty ratio D is fixed to D2 (D1 ≠ D2), and the frequency f is changed according to the oil temperature TF.

As described above, the target value calculation unit 51 (main computer 5) sends the detected value of the oil temperature TF during the stop period of the electric oil pump 2 to the motor operation amount calculation unit 41 (pump drive) via the first signal line SL1. In the operation period of the electric oil pump 2, the target value of the electric oil pump 2 is replaced with the detected value of the oil temperature TF, and the motor operation amount calculation unit 41 (pump) is also sent via the first signal line SL1. Output to the driving computer 4).
Therefore, the number of temperature sensors and the number of harnesses for temperature sensors can be reduced as compared with the case where the main computer 5 and the pump drive computer 4 are each provided with a temperature sensor for detecting the oil temperature TF, and one signal Since the line SL1 can be shared and the target value and the oil temperature TF can be transmitted, the number of signal lines SL (harness) connecting the main computer 5 and the pump drive computer 4 can be reduced as much as possible.

Thereby, setting of a target value corresponding to the oil temperature TF in the main computer 5 and pump control corresponding to the oil temperature TF in the pump drive computer 4 can be realized while suppressing an increase in cost, deterioration in layout performance, and the like.
Also, when the operation amount is limited according to the current integrated value, the current integrated value is reset when the pump is stopped.If the oil is not restarted after the pump is stopped, If the current upper limit value is set to an excessively high value with respect to the oil temperature and a high current is allowed, there is a possibility of overheating the motor and the drive circuit.

However, if the operation amount is limited based on the detection result of the oil temperature sensor 6 as described above, the motor, the drive circuit, etc. may be overheated even if the oil temperature is restarted without being lowered. Can be suppressed.
In addition, when the motor current is limited based on the estimated temperature value, the accuracy of the estimated temperature value is low, and if an estimated temperature is lower than the actual value, an excessively high current is allowed, and conversely, a higher temperature than the actual value. However, in the configuration in which the operation amount is limited based on the detection result of the oil temperature sensor 6 as described above, the current is limited without excess or deficiency. be able to.

Here, an example of the motor current limiting process by the motor operation amount calculation unit 41 of the pump drive computer 4 will be described with reference to the flowchart of FIG.
The routine shown in the flowchart of FIG. 5 shows the processing contents in the motor operation amount calculation unit 41, which is executed every predetermined minute time in the pump drive computer 4.

First, in step S101, after the electric motor 21 (electric oil pump 2) is started, in other words, the timer INITTMR indicating the time since the oil circulation to the transmission 1 is started is executed.
The elapsed time INITTMR is reset to zero during the stop period of the electric motor 21 (electric oil pump 2), and is increased by a constant value every execution period of this routine during the drive period of the electric motor 21 (electric oil pump 2). .

In step S102, the oil temperature TF (° C.) used for setting the current upper limit value based on the oil temperature TF (oil temperature detection value) transmitted from the main computer 5 during the stop period of the electric motor 21 (electric oil pump 2). Update.
In step S103, it is determined whether or not the elapsed time INITTMR after activation exceeds the set time t1, and if the elapsed time INITTMR is within the set time t1 and the electric oil pump 2 is activated, the process proceeds to step S104. move on.

In step S104, the current limit offset time LIMOFSTTIM is set based on the oil temperature TF.
Here, as shown in FIG. 6, the offset time LIMOFSTTIM (seconds) is set to zero when the oil temperature TF is the specified initial oil temperature, and the offset time LIMOFSTTIM (seconds) becomes higher as the oil temperature TF becomes higher than the specified initial oil temperature. Set to a long time.

In the next step S105, processing for setting the offset time LIMOFSTTIM as an initial value in the current limit timer LIMCURCNT is performed.
On the other hand, if it is determined in step S103 that the elapsed time INITTMR has exceeded the set time t1 and the initial value of the current limit timer LIMCURCNT has been set, the process proceeds to step S106 and the current limit timer LIMCURCNT is set to the previous value. The current limit timer LIMCURCNT is updated, which is increased by the set value.
Then, after step S105 or step S106, the process proceeds to step S107, where the current upper limit value (limit current) ECMAX is set based on the current limit timer LIMCURCNT.

As shown in FIG. 7, the correlation between the current limit timer LIMCURCNT and the current upper limit ECMAX is set in advance as a table. In this table, as the measurement time by the current limit timer LIMCURCNT becomes longer (in other words, the operation time The current upper limit value ECMAX is set to be gradually decreased as the oil temperature rises as the time elapses).
The correlation between the current limit timer LIMCURCNT and the current upper limit ECMAX is based on the oil temperature rise characteristics over time when starting at the specified initial oil temperature (very low temperature) and the current upper limit ECMAX for each oil temperature. It is preset based on this.

That is, when starting at a specified initial oil temperature, if the current upper limit value ECMAX is determined by referring to the table based on the actual elapsed time INITTMR, the current upper limit value ECMAX corresponding to the oil temperature TF at that time is determined. Can be set.
Here, when the electric motor 21 (electric oil pump 2) is stopped, the oil temperature TF transmitted from the main computer 5 becomes the actual initial oil temperature, and this actual initial oil temperature is higher than the prescribed initial oil temperature. When the current upper limit value ECMAX is determined by referring to the table based on the actual elapsed time INITTMR, the current upper limit value ECMAX suitable for the oil temperature lower than the actual temperature is set.

When the current upper limit value ECMAX is set based on a temperature lower than the actual temperature, a motor current that allows the temperature of the drive circuit 3 or the like to exceed the thermal life limit is allowed.
Therefore, in order to determine the timing when the actual initial oil temperature is reached when starting at the specified initial oil temperature as the timing for determining the current upper limit ECMAX with reference to the table at the start of startup, In step S104, the current limit offset time LIMOFSTTIM is determined based on the oil temperature TF. In step S105, the value of the current limit timer LIMCURCNT at the time of referring to the table is set to a later time as the actual initial oil temperature is higher. It is designed to be offset.

That is, when starting the pump at the specified initial oil temperature, the offset time LIMOFSTTIM is set to zero, and the current upper limit value ECMAX is set by referring to the table based on the current limit timer LIMCUCNT indicating the actual elapsed time from the start. .
On the other hand, when starting the pump at an oil temperature higher than the specified initial oil temperature, the offset time LIMOFSTTIM is increased as the actual initial oil temperature is higher than the specified initial oil temperature. By referring to the table based on the current limit timer LIMCUCNT, which is the time obtained by adding the offset time LIMOFSTTIM to the elapsed time of, and setting the current upper limit ECMAX, the elapsed time from startup is the same as the actual initial oil temperature is higher However, a lower current upper limit ECMAX is set.

As a result, the current upper limit ECMAX corresponding to the temperature increase from the actual initial oil temperature can be set with reference to a table that matches when the engine is started at the specified initial oil temperature. Therefore, even if the electric oil pump 2 is shut down and restarted before the oil temperature has fallen, the current upper limit ECMAX can be set according to the actual oil temperature, and the thermal life limit can be set. It is possible to suppress the temperature from rising to a temperature exceeding or limiting the motor current to be excessively low.
When the current upper limit value ECMAX is set in step S107, in step S108, the current upper limit value ECMAX is compared with the actual current detected by the motor current detection unit 43, so that a current limit flag indicating whether or not current limit processing is necessary is set. Set up.

The current limit flag has an initial value of zero. For example, if the actual current is greater than or equal to the current upper limit value ECMAX, 1 is set. If the current limit flag is set to 1, the actual current is the current upper limit. If the state below the value ECMAX continues for the set time, the current limit flag is reset to zero. If the current limit flag is 1, it indicates that the power supply restriction is performed. If the current limit flag is zero, the current limit flag is not performed.
In step S109, the current limit flag is determined. If the current limit flag is zero, the process proceeds to step S110.

In step S110, normal drive control of the electric motor 21 (electric oil pump 2) that outputs without limitation the operation amount (duty ratio) calculated based on the comparison between the target value and the control amount is performed.
On the other hand, if it is determined in step S109 that the current limit flag is 1, the process proceeds to step S111.

In step S111, the operation amount (duty ratio) calculated based on the comparison between the target value and the control amount is reduced by a predetermined value and then output to the drive circuit 3, thereby reducing the motor current. In step S111, the operation amount (duty ratio) is gradually decreased until the current limit flag switches to zero, that is, until the motor current becomes stable and falls below the current upper limit value ECMAX.
As a result, it is possible to suppress a state in which a current whose temperature exceeds the thermal life limit (allowable maximum temperature) flows to the electric motor 21, and it is possible to suppress thermal deterioration and thermal damage of the drive circuit 3 and the electric motor 21.

Next, an example of failure diagnosis in the pump drive computer 4 and output processing of failure information and rotation speed information will be described with reference to the flowchart of FIG.
The routine shown in the flowchart of FIG. 8 is executed every predetermined minute time in the pump drive computer 4. First, in step S201 (the motor operation amount calculation unit 41), the duty ratio D of the pulse signal SIG is detected to indicate the routine. The set target values (target motor speed, target motor current) are specified.

In the next step S202 (motor rotational speed calculation unit 42), the motor rotational speed (rpm) is calculated.
In step S203 (self-diagnosis unit 44), the presence or absence of a failure (abnormality) in driving the electric motor 21 is diagnosed from the motor current, the motor rotation speed, the target value, the power supply voltage, and the like.

For example, the control amount (motor rotation speed, motor current) does not converge to the target value, or the motor current or the motor rotation speed is zero even though the duty ratio for flowing current to the electric motor 21 is output. When the duty ratio for stopping the electric motor 21 is output but the motor current or the motor speed is not zero, a failure of the electric motor 21 or the drive system of the electric motor 21 is estimated.
In step S204, it is determined whether or not a failure has been diagnosed.

If no failure has occurred, the process proceeds to step S205, where the current limit flag is determined. If the current power flag is 1, the process proceeds to step S206, where the pump drive computer 4 to the main computer 5 The duty ratio D2 set in advance is set as the duty ratio D of the pulse signal STATE output to the rotation speed / failure information determination unit 52b.
In the non-current limit state in which the current power flag is zero, the process proceeds to step S207, where the duty ratio D of the pulse signal STATE output from the pump drive computer 4 to the rotation speed / failure information determination unit 52b of the main computer 5 is set in advance. The set duty ratio D1 (D1 ≠ D2) is set.

After step S206 or step S207, the process proceeds to step S208, where the motor rotational speed at that time is converted into a frequency f according to a preset characteristic so that the motor rotational speed can be specified from the frequency f.
That is, when there is no failure, the duty ratio D is set to D1 or D2 depending on whether or not the current is limited, and the frequency f of the pulse signal STATE with the duty ratio D corresponds to the motor rotation speed at that time. The frequency f to be output is output to the rotation speed / failure information determination unit 52b of the main computer 5.

FIG. 9A shows the characteristics of the pulse signal STATE when there is no failure. When the duty ratio D is D1 or D2, the frequency f within the specified range is, for example, higher as the frequency increases. ) Is high.
On the other hand, if it is determined in step S204 that a failure has been diagnosed, the process proceeds to step S209, and the duty ratio D of the pulse signal STATE is set to D3 (D1 ≠ D3 and D2 ≠ D3).

In the next step S210, the failure information is converted into a frequency f according to a preset characteristic so that the failure state can be determined from the frequency f of the pulse signal STATE. For example, the frequency f is set to f1 in the case of a failure in which the current of the electric motor 21 cannot be interrupted, and conversely, the frequency f is set to f2 (f1 ≠ f2) in the case of a failure in which no current can flow through the electric motor 21. To do.
FIG. 9B shows the characteristics of the pulse signal STATE when a failure occurs. When the duty ratio D is D3, the frequency f within the specified range corresponds to specific failure information.

In step S211, the pulse signal STATE having the duty D set as described above (any one of D1, D2, and D3) and the frequency f is sent to the rotation speed / failure information determination unit 52 of the main computer 5 as a second signal. Output via line SL2.
The processes in steps S204 to S211 above show the function of the rotation speed / failure information transmission unit 45.

The rotation speed / failure information determination unit 52 of the main computer 5 measures the duty ratio D and the frequency f of the pulse signal STATE. If the duty ratio D is D1 or D2, it is determined that there is no failure. Further, it is determined whether the current is in a current limiting state based on whether the duty ratio D is D1 or D2. Further, if the duty ratio D is D1 or D2, the motor at that time is determined from the frequency f. Determine the number of revolutions.
Further, if the duty ratio D of the pulse signal STATE is D3, the rotation speed / failure information determination unit 52 determines that some failure has occurred in the driving of the electric motor 21, and further determines the failure state from the frequency f. Is determined.

As shown in FIG. 9, the rotational speed / failure information determination unit 52 is connected to the pump drive computer 4 via the second signal line SL2 when the pulse signal STATE having a frequency f outside the specified range is input. An abnormality in the communication system with the computer 5 can be determined.
Further, instead of switching the duty ratio D of the pulse signal STATE according to the presence / absence of current limitation and the presence / absence of failure, as shown in FIG. 10, the frequency f of the pulse signal STATE is changed to the presence / absence of current limitation and presence / absence of failure. It can be switched in accordance with the duty ratio D to indicate the motor rotation speed and failure information.

FIG. 10A shows the characteristics of the pulse signal STATE when there is no failure, indicating whether the current is limited or not depending on whether the frequency f is f1 or f2 (f1 ≠ f2). For example, the higher the duty ratio D, the higher the motor rotation speed (rpm).
FIG. 10B shows the characteristics of the pulse signal STATE at the time of failure occurrence, indicating that the failure diagnosis has been performed when the frequency f is f3 (f1 ≠ f3 and f2 ≠ f3). The duty ratio D within the specified range corresponds to specific failure information.

  Further, when the characteristics of the pulse signal STATE shown in FIG. 10 are used, when the rotation speed / failure information determination unit 52 inputs a pulse signal STATE having a duty ratio D outside the specified range, the second signal line SL2 is set. The abnormality of the communication system between the pump drive computer 4 and the main computer 5 can be determined.

FIG. 11 is a functional block diagram illustrating an example of details of the target value calculation unit 51, the rotation speed / failure information determination unit 52, the rotation speed calculation unit 53, and the diagnosis / protection control unit 54 in the main computer 5. FIG. 11 illustrates a control function when the electric oil pump 2 supplies oil for cooling.
The pulse signal STATE transmitted from the pump drive computer 4 is input to the rotation / state signal input unit 52a, where the duty ratio D and the frequency f of the pulse signal STATE are measured.

Then, the measurement result of the duty ratio D and the frequency f of the pulse signal STATE is sent to the abnormality / current limit receiving unit 52b. For example, the normal state, the current limit state, and the failure state are determined from the duty ratio D, and the duty ratio is determined. When D indicates that it is in a normal state or a current limit state, the frequency f of the pulse signal STATE indicates the motor rotation number, and therefore information on the frequency f is sent to the rotation number calculation unit 53.
The rotation / state signal input unit 52a and the abnormality / current limit reception unit 52b constitute the rotation speed / failure information determination unit 52 in FIG.

The determination result of the normal state, the current limit state, and the failure state in the abnormality / current limit receiving unit 52b is sent to the electric oil pump operation command unit 54a and the protection control unit (vehicle travel limit unit) 54b constituting the diagnosis / protection control unit 54. Is output.
The electric oil pump operation command unit 54a outputs an operation permission of the electric oil pump 2 to the requested rotational speed calculation unit 51a in a normal state or a current limiting state, and issues an instruction to stop the operation of the electric oil pump 2 in a failure state. It outputs to the request | requirement rotation speed calculating part 51a.

On the other hand, the protection control unit (vehicle travel restriction unit) 54b performs a process of restricting vehicle travel such as restricting an increase in engine torque in a current restriction state or a failure state.
In the current limiting state, the pump flow rate (oil discharge amount) is lower than required, and overheating or poor lubrication may occur when oil for lubrication or cooling is supplied by the electric oil pump 2. . Therefore, in the current limiting state, the protection control unit 54b controls the engine torque to such an extent that overheating and poor lubrication can be suppressed with the actual pump flow rate (actual oil discharge amount, actual motor speed). An upper limit is set, and a fail-safe process for limiting the engine torque (input torque of the transmission 1) to the upper limit torque or less is performed.

In the internal combustion engine, the engine torque is limited by increasing the intake air amount (decreasing the maximum stall opening) or the like.
Further, in the failure state, the protection control unit 54b performs fail-safe processing, for example, prohibiting power transmission (clutch engagement) via the transmission 1 or stopping the engine.

On the other hand, the motor rotation number calculated by the rotation number calculation unit 53 is output to the pump flow rate calculation unit 51b, and the pump flow rate calculation unit 51b calculates the pump flow rate from the motor rotation number.
The electric oil pump cooling amount calculation unit 51c inputs the pump flow rate, and calculates the cooling amount (heat absorption amount) by the oil from this pump flow rate.

On the other hand, in the oil supply destination heat generation amount calculation unit 51d, if the cooling oil supply destination is a clutch, for example, the input torque and the slip rotation speed (input / output) are calculated. Calculate based on the difference in shaft speed.
Then, if the operation permission is instructed from the electric oil pump operation command unit 54a, the required rotation number calculation unit 51a is a target motor rotation number corresponding to the pump flow rate required from the cooling amount (heat absorption amount) and the heat generation amount. (Or target motor current) is calculated. Further, the requested rotational speed calculation unit 51a sets the target motor rotational speed (or the target motor current) to zero in order to stop the operation of the electric oil pump 2 in a failure state.

The required rotation speed output unit 51 e converts the target value information of the electric oil pump 2 into, for example, a duty ratio D, and outputs a pulse signal SIG having the duty ratio D to the pump drive computer 4.
The target speed calculator 51 is configured by the required rotational speed calculator 51a, the pump flow rate calculator 51b, the electric oil pump cooling amount calculator 51c, the oil supply destination heating amount calculator 51d, and the required rotational speed output unit 51e.

Below, an example of the control function of the main computer 5 shown in said functional block diagram is demonstrated according to a flowchart.
The flowchart of FIG. 12 shows a main routine of processing in the main computer 5, and this main routine is executed in the main computer 5 every predetermined minute time.

First, in step S301 (rotation speed / state signal input unit 52a), the duty ratio D and the frequency f of the pulse signal STATE are read.
In step S302 (abnormal / current limit receiving unit 52b), the drive state of the electric motor 21 is determined by analyzing the duty ratio D and the frequency f of the pulse signal STATE.

In step S303 (abnormal / current limit receiving unit 52b), the drive state of the electric motor 21 is determined as one of a normal state (non-current limit state), a current limit state, and a failure state.
In a normal state in which there is no failure and current limitation is not performed, the process proceeds to step S304 (target calculation unit 51, diagnosis / protection control unit 54), and processing corresponding to the normal state (normal rotation) as target value calculation processing Time processing).

In the current limit state in which the increase in the operation amount is limited so that the actual current falls below the current upper limit value ECMAX, although it is not in the failure state, step S305 (target calculation unit 51, diagnosis / protection control unit 54). Then, the process corresponding to the current limit state (current limit process) is performed as the target value calculation process.
Further, in the failure state where the occurrence of some failure is diagnosed, the process proceeds to step S306 (target calculation unit 51, diagnosis / protection control unit 54), and processing corresponding to the failure state as the target value calculation processing (fail time processing) To implement.

Below, the content of the processing in step S304, step S305, and step S306 will be described according to the flowcharts of FIGS.
The flowchart of FIG. 13 shows an example of the process in step S304 (normal rotation process) performed in a normal state.

In the flowchart of FIG. 13, first, in step S <b> 401 (the rotational speed calculation unit 53), the motor rotational speed (rpm) is calculated from the frequency f (or duty ratio D) of the pulse signal STATE.
In step S402 (pump flow rate calculation unit 51b), the pump flow rate in the electric oil pump 2 is calculated from the motor rotation speed.

In step S403 (electric oil pump cooling amount calculation unit 51c), a cooling amount (heat release amount) of an oil supply destination (cooling target) such as a clutch is calculated. In step S404 (oil supply destination heat generation amount calculation unit 51d), an oil amount is calculated. Calculate the calorific value of the supply destination (cooling target).
In step S405 (required rotational speed calculation unit 51a), the oil flow rate required for cooling the oil supply destination (cooling target) is calculated from the cooling amount (heat radiation amount) and the heat generation amount.

  In step S406 (required rotational speed calculation unit 51a), the motor rotational speed at which the required oil flow rate can be obtained is calculated as a target value. In step S407 (required rotational speed output unit 51e), the target motor rotational speed calculated in step S406 is calculated. A pulse signal SIG having a designated duty ratio D (or frequency f) is output to the pump drive computer 4.

The flowchart of FIG. 14 shows an example of the process of step S305 (current limit process) performed in the current limit state.
In the flowchart of FIG. 14, first, in step S501 (protection control unit 54b), an abnormal flag indicating that the current is limited is set, and the increase in current is limited, so that the oil flow rate is higher than required. Therefore, a travel restriction process (for example, a process for restricting an increase in engine torque) is performed to suppress the heat generation amount (in other words, the required oil flow rate) of the oil supply destination (cooling target).
Thereafter, in steps S502 to S508, the target motor rotational speed is calculated and output in the same manner as in steps S401 to S407.

The flowchart of FIG. 15 shows an example of the process of step S306 (fail process) performed in the failure state.
In the flowchart of FIG. 15, first, in step S601 (protection control unit 54b), an abnormal flag indicating a failure state is set, and the oil supply from the electric oil pump 2 is stopped, whereby the oil supply is performed. Since cooling cannot be performed, a travel restriction process (for example, engine stop or clutch engagement prohibition in the transmission 1) that is stricter than the restriction in step S501 is performed.

In step S602, the detected value of the motor speed is set to zero, and in step S603, the detected value of the pump flow rate is set to zero.
In step S604, the cooling amount is calculated in the same manner as in step S403, and in step S605, the heat generation amount is calculated in the same manner as in step S404.
In step S606, the target motor speed is set to zero (rotation stop), and in step S607, the pulse signal SIG instructing target motor speed = 0 (stop of the electric oil pump 2) is sent to the pump drive computer 4. Output to.

The oil supply destination of the electric oil pump 2 is not limited to 1 for the transmission, and a hydraulic device such as a power steering device can be the supply destination.
In addition, the pump drive computer 4 can estimate the change in the oil temperature TF from conditions such as the subsequent cooling amount and heat generation amount, with the oil temperature TF input during the stop period of the electric oil pump 2 as an initial value.
Moreover, the pump drive computer 4, the drive circuit 3, the electric oil pump 2, etc. can be provided integrally.
Further, as an oil pump that supplies oil to the transmission 1, an oil pump that is driven by an engine can be provided together with the electric oil pump 2.

Here, technical ideas other than the claims that can be grasped from the above embodiment will be described together with effects.
(A) The electric oil pump for a vehicle according to any one of claims 1 to 3, wherein the electric oil pump supplies oil to a transmission in a hybrid vehicle.
According to the above invention, in the electric oil pump that supplies oil to the transmission of the hybrid vehicle, it is possible to control the electric oil pump with high accuracy based on the detected value of the oil temperature while suppressing an increase in cost and a deterioration in layout.

(B) Information on the rotational speed of the electric oil pump and failure information from the second unit to the first unit using a signal line different from the signal line used for transmitting the target value and the oil temperature. The control device for an electric oil pump for a vehicle according to any one of claims 1 to 3, which outputs at least one of the following.
According to the said invention, the 1st unit can set appropriately the target value output to a 2nd unit by inputting at least one of the rotation speed and failure information of an electric oil pump.

(C) The second unit instructs one of the duty ratio and the frequency of the pulse signal transmitted to the first unit and changes the other by instructing information on the rotational speed and failure information of the electric oil pump. The fixed value of the duty ratio or frequency is set to a different value depending on whether the information on the number of rotations of the electric oil pump is output or the case where the failure information is output. Control device for electric oil pump.
According to the above invention, information on the rotational speed of the electric oil pump and failure information can be transmitted using one signal line.

(D) a unit that outputs a control target value of an electric oil pump for a vehicle, wherein the first unit outputs a detected value of oil temperature during a stop period of the electric oil pump, and the first unit outputs A second unit that inputs a control target value and a detected value of the oil temperature, and outputs an operation amount of the electric oil pump, and the second unit controls the electric oil pump based on the detected value of the oil temperature. A control device for an electric oil pump for a vehicle that calculates an upper limit value of the amount and limits the operation amount so that a control amount of the electric oil pump does not exceed the upper limit value.
According to the above invention, the amount of operation that exceeds the thermal life limit differs depending on the oil temperature, so by limiting the operation amount so that the control amount such as current does not exceed the upper limit set according to the oil temperature. Further, it is possible to suppress the operation amount from being excessively limited while suppressing the temperature from exceeding the thermal life limit.

(E) The second unit uses a signal line that is different from a signal line used for transmitting the target value and the oil temperature as a signal indicating whether or not the operation amount is limited. To the unit,
The control device for an electric oil pump for a vehicle according to claim (d), wherein the first unit restricts traveling of the vehicle when the operation amount is restricted.
According to the above invention, when the pump flow rate (oil flow rate) is lower than required due to the restriction of the operation amount, the increase in engine torque is restricted so that the temperature does not exceed the thermal life limit even with the reduced oil flow rate. Limiting the travel of the vehicle.

  DESCRIPTION OF SYMBOLS 1 ... Transmission, 2 ... Electric oil pump, 3 ... Drive circuit, 4 ... Pump drive computer (2nd unit), 5 ... Main computer (1st unit), 6 ... Oil temperature sensor

Claims (3)

A unit for outputting a control target value of an electric oil pump for a vehicle, wherein the first unit outputs an oil temperature detection value during a stop period of the electric oil pump;
A second unit that inputs the control target value output by the first unit and a detected value of the oil temperature, and outputs an operation amount of the electric oil pump;
With
In the second unit, the current of the electric motor that drives the electric oil pump corresponds to the detected value of the oil temperature input during the stop period of the electric oil pump and the elapsed time since the electric oil pump was started. A control device for an electric oil pump for a vehicle that limits an operation amount of the electric oil pump so as not to exceed an upper limit value of current. The first unit outputs an oil temperature detection value instead of the control target value during a stop period of the electric oil pump, and the control target instead of the oil temperature detection value during an operation period of the electric oil pump. Output the value,
2. The electric oil pump for a vehicle according to claim 1, wherein when the first unit outputs the detected value of the oil temperature, the second unit cuts off the power supply to the electric oil pump and stops the operation. 3. Control device. The first unit varies the frequency of the pulse signal output when outputting the detected value of the oil temperature and when outputting the control target value, and the duty of the pulse signal is changed during the stop period of the electric oil pump. The ratio is changed according to the detected value of the oil temperature, the duty ratio of the pulse signal is changed according to the control target value during the operation period of the electric oil pump,
The second unit measures a frequency and a duty ratio of the pulse signal output from the first unit to obtain a detection value of the oil temperature and the control target value;
The control apparatus for an electric oil pump for a vehicle according to claim 2.