JP2022034126A - Idling stop control device - Google Patents

Abstract

To provide an idling stop control device capable of measuring internal loss of an engine by using small energy and attaining idling stop control reflecting the measured internal loss.SOLUTION: An idling stop control device includes: an engine measurement section for measuring internal loss of an engine; a stop processing section performing processing for determining whether or not an idling operation of the engine is stopped on the basis of a charging state of an accessory battery and the internal loss measured by the engine measurement section and stopping the idling operation when the stop of the idling operation is determined; and a driving processing section for applying kinetic energy smaller than start energy to the engine to cause the engine to generate motion less than starting. The engine measurement section measures the internal loss of the engine on the basis of the motion less than starting.SELECTED DRAWING: Figure 9

Description

The present invention relates to an idling stop control device.

There is an idling stop function that stops the idling operation of the engine when the vehicle is temporarily stopped. The fuel efficiency of the vehicle can be improved by stopping the idling operation.

Patent Document 1 discloses a function of determining whether or not an internal loss (friction) of an engine has increased when the engine is started.

Japanese Unexamined Patent Publication No. 2001-099886

Generally, when the idling operation is stopped, it is determined whether the SOC (State of Charge) of the auxiliary battery is equal to or higher than the threshold value, and if the SOC (State of Charge) is equal to or higher than the threshold value, the idling operation is stopped. The SOC threshold value is set to a value capable of outputting the electric power required for restarting the engine. This determination process prevents the engine from being unable to restart due to insufficient power after the idling operation is stopped.

On the other hand, the electric power required to restart the engine changes due to the friction of the engine. In addition, the friction of the engine is high at the time of a new car and decreases after running-in, and changes depending on the time. However, in the conventional idling stop function, the SOC threshold value of the auxiliary battery is determined on the assumption that the internal loss is the largest. Therefore, when the internal loss of the engine is small, the determination margin for determining whether or not to stop the idling operation becomes larger than necessary. Due to the large determination margin, it was determined that the engine could not be restarted even though the idling operation could actually be stopped, and the idling operation might not be stopped.

By measuring the friction of the engine, reflecting the measurement result, and reducing the margin of the above judgment, it is possible to increase the chances that the idling operation can be stopped. However, if a large amount of energy is consumed to measure friction, the effect of improving fuel efficiency, which is an advantage of the idling stop function, is adversely affected.

An object of the present invention is to provide an idling stop control device capable of measuring the internal loss of an engine with a small amount of energy and realizing idling stop control reflecting the measured internal loss.

The invention according to claim 1 is
An idling stop control device mounted on a vehicle having an engine, a starting motor for restarting the engine, and an auxiliary battery for supplying electric power to the starting motor.
The engine measurement unit that measures the internal loss of the engine,
Based on the charge state of the auxiliary battery and the internal loss measured by the engine measuring unit, a process of determining whether to stop the idling operation of the engine is performed, and when it is determined to stop, the idling operation is performed. And the stop processing unit to stop
A drive processing unit that applies kinetic energy smaller than the starting energy to the engine to generate motion less than starting in the engine.
Equipped with
The engine measuring unit is characterized in that the internal loss is measured based on the motion less than the starting.

The invention according to claim 2 is the idling stop control device according to claim 1.
It is equipped with a switching processing unit that lowers the rotational resistance of the engine.
The engine measuring unit is characterized in that the rotational resistance is lowered by the switching processing unit when measuring the internal loss.

The invention according to claim 3 is the idling stop control device according to claim 1 or 2.
The condition for the engine measuring unit to measure the internal loss includes a condition that the auxiliary battery has a charge amount equal to or higher than a threshold value.

The invention according to claim 4 is the idling stop control device according to any one of claims 1 to 3.
The engine measuring unit is characterized in that it determines whether or not the environment of the engine meets the conditions, and if the environment meets the conditions, measures the internal loss.

The invention according to claim 5 is the idling stop control device according to any one of claims 1 to 4.
The engine measuring unit measures the internal loss when the environment of the engine is warm and cold.
The stop processing unit is used when the temperature is different from the warm temperature and the cold temperature based on the internal loss measured when the temperature is warm and the internal loss measured when the temperature is cold. It is characterized in that the internal loss of the engine is estimated and the determination process is performed based on the estimated internal loss.

According to the present invention, the engine measuring unit measures the internal loss of the engine, and it is determined whether or not the stop processing unit stops the idling operation of the engine based on the measured internal loss and the charge state of the auxiliary battery. Perform processing. Therefore, even if the internal loss of the engine changes depending on the total mileage, aging, maintenance status, etc., the stop processing unit can perform determination processing according to the changed internal loss. Therefore, the determination margin when determining whether or not the engine can be restarted becomes small, and the chance of idling stop can be increased.

Further, according to the present invention, the drive processing unit causes the engine to generate a motion less than the start, and the engine measurement unit measures the internal loss based on the motion less than the start of the engine. Therefore, labor saving when measuring the internal loss can be achieved, and the fuel efficiency of the vehicle can be improved in combination with the effect of the idling stop function.

It is a figure which shows the vehicle which mounted the idling control device which concerns on Embodiment 1 of this invention. It is a flowchart which shows the idling stop control process which the system control part executes. It is a time chart explaining the measurement process of the internal loss of an engine. It is a flowchart which shows the process at the time of a ready-on which is executed by a system control part. It is a flowchart which shows the process at the time of the ready-on of the modification 1 in Embodiment 1. FIG. It is a flowchart which shows the process at the time of the ready-on of the modification 2 in Embodiment 1. It is a figure which shows the vehicle which mounted the idling stop control device which concerns on Embodiment 2 of this invention. It is a time chart explaining the measurement process of the internal loss of an engine in Embodiment 2. A flowchart showing an SOC threshold update process executed by the system control unit of the second embodiment. It is a flowchart which shows the SOC threshold value update process of the modification 3 in Embodiment 2.

Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a diagram showing a vehicle equipped with the idling control device according to the first embodiment of the present invention. The vehicle 1 according to the first embodiment includes a drive wheel 2, an engine 4 that outputs power to the drive wheel 2, an auxiliary device 5 for driving the engine 4, and an ISG (Integrated Starter) that starts or restarts the engine 4. Generator) 6, auxiliary battery 8 that supplies power to ISG 6 and auxiliary equipment 5, driving operation unit 20 that receives the driving operation of the driver, driving control unit 21 that controls the driving of vehicle 1, and the system of vehicle 1. A system control unit 22 for controlling is provided. The system control unit 22 functions as an idling stop control device. The system control unit 22 includes a stop processing unit 22A that performs idling stop control and an engine measurement unit 22B that measures the internal loss of the engine 4. The ISG6 functions as a starting motor. The starting motor may be referred to as a restart motor.

Further, the vehicle 1 includes a vehicle speed sensor 30, a gradient sensor 31 for detecting the gradient of the traveling road surface, a rotation sensor 32 for detecting the rotational speed of the engine 4, and a liquid temperature sensor 33 for measuring the temperature of the coolant of the engine 4. The oil temperature sensor 34 for measuring the oil temperature of the engine 4 and the level sensor 35 for detecting the oil level of the engine oil are provided.

The auxiliary battery 8 is, for example, a lead battery that outputs a voltage of a 12V system. The auxiliary battery 8 is provided with a management unit 8a that monitors current, voltage, and temperature and manages SOC (charge state). The management unit 8a sends information on the temperature, current, voltage, and SOC of the auxiliary battery 8 to the system control unit 22.

The ISG 6 has a function of an electric motor that starts or restarts the engine 4 and a function of a generator that receives a part of the power of the vehicle 1 to generate electric power. The ISG 6 is driven by the electric power of the auxiliary battery 8. On the other hand, the electric power generated by the ISG 6 is stored in the auxiliary battery 8.

The operation operation unit 20 includes an accelerator operation unit, a braking operation unit, and a steering operation unit. When the driver operates the accelerator operation unit, an operation signal indicating the amount of operation of the accelerator operation unit is output from the operation operation unit 20 to the travel control unit 21. The travel control unit 21 drives the auxiliary machine 5 in response to the operation signal of the accelerator operation unit, and controls the output torque of the engine 4. By such control, the running of the vehicle 1 according to the driving operation is realized.

The operation operation unit 20 further includes an activation operation unit such as an ignition key cylinder or an activation button. When the driver operates the start operation unit, an operation signal is sent from the operation operation unit 20 to the system control unit 22, and the system control unit 22 starts or suspends the system of the vehicle 1. The activation of the system means that the travel control unit 21 is activated and the vehicle 1 is capable of traveling in accordance with the driving operation of traveling, and the system suspension means that the traveling control unit 21 is suspended and the driving operation is performed. However, it means that the vehicle 1 does not run. When the system is started, the system control unit 22 drives the ISG 6 to start the engine 4. The engine 4 may be started at a different timing.

The system control unit 22 has a soak timer 22a. The soak timer 22a measures the time from when the system is stopped to when the next system is started.

<Idling stop control>
FIG. 2 is a flowchart showing an idling stop control process executed by the system control unit. The system control unit 22 starts the idling stop control process of FIG. 2 when the vehicle speed becomes zero during traveling. When the idling stop control process is started, first, the stop process unit 22A determines whether or not the conditions for idling stop in the driving operation are satisfied (step J1). The condition for the operation operation is a condition such as whether the braking operation unit is operated by a predetermined amount or more and the operation is continued for a predetermined time (several seconds) or more. Further, the stop processing unit 22A determines whether the state of the vehicle 1 satisfies the condition (step J2). The condition of the state of the vehicle 1 is a condition that the road surface gradient is equal to or less than a predetermined value. Further, the stop processing unit 22A determines whether the SOC of the auxiliary battery 8 is equal to or higher than the SOC threshold value (step J3). Then, when the determination results of steps J1 to J3 are both YES, the idling operation is stopped (step J4). On the other hand, when any of the determination results of steps J1 to J3 is NO and the vehicle 1 resumes traveling (YES in step J7), the idling stop control process is terminated as it is. After the idling operation is stopped in step J4, the system control unit 22 repeats the process of determining whether or not the idling stop release condition has occurred, such as the operation of the braking operation unit being released (step J5), and the release condition. If there is, the engine 4 is restarted (step J6), and the idling stop control process is terminated.

The SOC threshold value used in the determination process of step J3 is set to a value obtained by adding a margin to the SOC of the auxiliary battery 8 required for restarting the engine 4. By such a determination process using the SOC threshold value, it is possible to prevent the engine 4 from being unable to restart due to insufficient SOC of the auxiliary battery 8 after the idling operation is stopped.

In the idling stop control, the timing at which the engine 4 is restarted after the idling operation is stopped is unknown. Therefore, assuming that the engine 4 has cooled sufficiently before restarting, the SOC threshold value for the determination process is set.

Further, the SOC of the auxiliary battery 8 required for restarting the engine 4 changes due to the internal loss of the engine 4. The internal loss of the engine 4 changes depending on the total mileage, aging, and maintenance status, for example, it is large at the time of a new car and small after running-in. Further, the internal loss changes even if the viscosity of the engine oil changes due to the replacement or deterioration of the engine oil. Therefore, by setting the SOC threshold value to a value that reflects the current internal loss, the determination process in step J3 becomes appropriate.

The internal loss of the engine 4 changes even in a short cycle such as when it is cold and when it is warm, but the internal loss at the present time is the basis of the internal loss which changes over a long period excluding the change in the short cycle. It means the bottom price (for example, the internal loss when the temperature parameter is fixed). As described above, in the idling stop control, since the restart timing of the next engine 4 is unknown, it is necessary to set the SOC threshold value so that the engine 4 can be restarted even when the engine 4 is sufficiently cooled. This is because changes in short cycles of internal loss do not affect such SOC thresholds.

<Measurement of internal loss of engine>
FIG. 3 is a time chart illustrating the measurement process of the internal loss of the engine. As shown in FIG. 3, when there is a start request at the timing t0, first, the rotational power is output from the ISG 6 to the engine 4 by the electric power of the auxiliary battery 8, and the rotational speed of the engine 4 increases (period T1). Then, the rotation speed of the engine 4 is increased, fuel injection and ignition operation by the auxiliary machine 5 are started, and then the engine 4 is in a complete explosion state in which the engine 4 is rotated only by the explosion of the fuel (timing t1). The fact that the engine 4 has completely exploded can be identified from the fact that the rotational speed of the engine 4 has risen above the threshold value at the time of complete explosion, or the phase difference between the ignition timing and the crank timing.

The engine measurement unit 22B calculates the internal loss of the engine 4 based on the output energy of the ISG 6 and the rate of increase in the rotational speed of the engine 4 during the period T1 before the engine 4 is completely detonated. The output energy of the ISG 6 can be obtained from, for example, the output power of the auxiliary battery 8 (power consumption of the ISG 6). If the internal loss of the engine 4 is large, the rate of increase in the rotational speed of the engine 4 with respect to the output energy of the ISG6 does not increase. The rate of increase will be high. That is, the value obtained by normalizing the rate of increase in the rotational speed of the engine 4 with the output energy of the ISG 6 correlates with the internal loss of the engine 4, and the internal loss can be obtained from the above value. The engine measurement unit 22B holds in advance a function or a data table showing the relationship between the above standardized value and the internal loss, and calculates the internal loss using these functions or data tables. The above function or data table can be obtained by experiment or simulation.

The engine measurement unit 22B may calculate the internal loss of the engine 4 by using other parameters in the period T1 before the engine 4 is completely detonated. The above parameters include the time from the start to the complete explosion, the workload of the ISG6 from the start to the complete explosion (area S in FIG. 3), and the rate of change in the rotational speed of the engine 4 at the time of start (average value of inclination). Etc.) etc. are included. Since these parameters correlate with the internal loss of the engine 4, the engine measurement unit 22B holds in advance a function or a data table showing the relationship between each of the above parameters and the internal loss of the engine 4, and uses these. The internal loss of the engine 4 can be calculated. The above function or data table can be obtained by experiment or simulation.

The engine measurement unit 22B further prepares the environment of the engine 4 and executes the above-mentioned internal loss measurement process. This is to measure the internal loss by excluding factors that change due to the environment. As the environmental condition for the engine measurement unit 22B to execute the measurement process in the first embodiment, the cold start condition in which the environment of the engine 4 is easily aligned is applied. That is, it is the first start of the engine 4 after the system is started, the value of the soak timer 22a at the time of system start (the time from the previous hibernation to the start) is equal to or higher than the threshold value, and the coolant temperature of the engine 4 is high. It is a condition that is equal to or less than the threshold value. Here, the threshold value of the soak timer 22a is set to the length of time during which the heat generated by driving the engine 4 is sufficiently released to the outside. The threshold value of the coolant temperature is set to the temperature at which the heat of the engine 4 during operation is sufficiently released to the outside.

Further, the engine measurement unit 22B does not perform measurement in the following exceptional situation in order to prepare the environment at the time of measurement. Alternatively, even if the engine measuring unit 22B performs the measurement, the stop processing unit 22A does not use the measured value when determining the SOC threshold value. In the above exception situation, when the road surface gradient is equal to or higher than the gradient threshold value, the oil level in the crankcase is lower than the threshold value, the coolant temperature of the engine 4, the oil temperature, the outside air temperature, and the temperature of the auxiliary battery 8 are set. When there is a difference of more than the threshold value, is included.

When the road surface gradient is equal to or higher than the gradient threshold value, the state of the oil hitting the connecting rod of the engine 4 changes from the normal state, and the measured internal loss of the engine 4 includes an error. When the oil level in the crankcase is low, the amount of oil that hits the connecting rod decreases, and the internal loss is measured low. A low measured value may cause a situation in which the engine 4 cannot be restarted even if it is determined that the engine 4 can be restarted. The situation where the plurality of temperatures have a difference of more than the threshold value does not match the condition of cold start. For these reasons, the engine measurement unit 22B treats the above situation as an exceptional situation.

<Processing at the time of ready-on>
Subsequently, the ready-on processing in which the measurement of the internal loss of the engine 4 by the engine measurement unit 22B and the update of the SOC initial value by the stop processing unit 22A will be described will be described. FIG. 4 is a flowchart showing the ready-on processing executed by the system control unit.

The ready-on process is started when a system boot operation is performed. When the ready-on processing is started, the system control unit 22 first performs system startup processing such as activating another control unit (step S1), and then the engine measurement unit 22B sets the cold start conditions. It is determined whether the condition is satisfied (step S2). If the condition is not satisfied, the system control unit 22 starts the engine 4 (step S3) and ends the ready-on process. On the other hand, if it is determined in step S2 that the condition is satisfied, the engine measurement unit 22B branches the process to step S4. The cold start condition in step S2 is determined as described above from the value of the soak timer 22a and the coolant temperature. In addition, the determination of whether or not it is an exceptional situation described above is added to the determination process of step S2, and if it is an exceptional situation, the process may be branched to step S3.

When the process proceeds to step S4, the engine measurement unit 22B first starts acquiring data on the output of the ISG 6 and the rotation speed of the engine 4 (step S4). Then, the system control unit 22 starts the engine 4 (step S5). Here, the engine 4 shifts to the complete explosion state, and the engine 4 starts. Next, the engine measurement unit 22B uses a data table or function held in advance based on the data of the output of ISG6 and the engine rotation speed acquired at each timing from step S4 to the complete explosion of the engine 4. Then, the internal loss of the engine 4 is calculated (step S6). In step S6, the internal loss may be calculated using the other parameters described above.

Next, the stop processing unit 22A calculates the SOC threshold value used when determining whether or not to stop the idling operation based on the calculated internal loss, and updates the SOC threshold value (step S7). The SOC threshold value is a value obtained by adding a predetermined margin to the SOC of the auxiliary battery 8 that enables the engine 4 to be restarted even when the engine 4 is sufficiently cooled after the idling operation is stopped. The internal loss calculated in step S6 is the internal loss when the engine 4 is cold, and correlates with the SOC of the auxiliary battery 8 that enables the restart. The stop processing unit 22A holds in advance a function or a data table showing the relationship between the internal loss during cold weather and the SOC threshold value optimized for it, and uses these to store the SOC threshold value corresponding to the calculated internal loss. Ask for. The above function or data table can be obtained by experiment or simulation. When the SOC threshold is updated in step S7, the ready-on processing ends.

By such ready-on processing, when the environment meets the conditions, the internal loss at the time of cold start of the engine 4 is measured and updated to the SOC threshold value reflecting the measured internal loss. Then, in the idling stop control process shown in FIG. 2, the updated SOC threshold value is used to execute the determination process of whether or not to stop the idling operation.

As described above, according to the vehicle 1 and the system control unit (idling stop control device) 22 of the first embodiment, the engine measurement unit 22B measures the internal loss of the engine 4. Then, the stop processing unit 22A determines the SOC threshold value based on the measured internal loss of the engine 4, and determines whether or not to stop the idling operation based on the comparison between the SOC of the auxiliary battery 8 and the SOC threshold value. I do. In other words, the stop processing unit 22A performs a determination process of whether or not to stop the idling operation based on the measured internal loss of the engine 4 and the SOC of the auxiliary battery 8. In this way, by reflecting the measured value of the internal loss in the above determination process, the determination margin of the determination process is increased as compared with the case where the above determination process is performed assuming the case where the internal loss is the largest. Can be made smaller. Therefore, even when the SOC of the auxiliary battery 8 is lowered to the vicinity of the SOC where there is little room for restarting the engine 4, the case where the idling operation is determined to be stopped increases, and the idling operation is stopped. You can increase the chances of

Further, according to the vehicle 1 and the system control unit 22 of the first embodiment, the engine measurement unit 22B measures the internal loss when the engine 4 is started. That is, since the internal loss is measured by using the movement of the engine 4 at the time of starting, it is not necessary to drive the engine 4 for the measurement, and the power consumed by the measurement can be reduced. Therefore, it can contribute to the improvement of the fuel efficiency of the vehicle 1.

Further, according to the vehicle 1 and the system control unit 22 of the first embodiment, the engine measurement unit 22B determines whether the environment of the engine 4 meets the conditions (for example, the condition at the time of cold start), and if the conditions are met. In addition, the internal loss of the engine 4 is measured. Changes in internal loss include environment-dependent changes such as cold and warm. On the other hand, the SOC threshold value is a value obtained by adding a predetermined margin to the SOC of the auxiliary battery 8 that enables the engine 4 to be restarted even when the engine 4 has cooled sufficiently after the idling operation is stopped. It is not related to the element of the internal loss of 4 that changes in a short cycle depending on the environment. Therefore, by measuring the internal loss of the engine 4 in the same environment, it is possible to eliminate the element that changes in a short cycle depending on the environment and measure the internal loss of the engine 4. Then, due to the internal loss measured in this way, the stop processing unit 22A can easily set an appropriate SOC threshold value.

The environmental condition of the engine 4 when measuring the internal loss is not limited to the condition of cold start, but is changed to the condition of a certain fixed temperature such as a medium temperature or a high temperature of the coolant. Even in this case, the same effect as described above can be obtained by preparing the environment. Further, the above environmental conditions include environmental conditions other than temperature, such as when the slope of the road surface on which the vehicle 1 is located is less than a predetermined angle, or when the oil level in the crankcase is less than a specified value. You may.

Further, according to the vehicle 1 and the system control unit 22 of the first embodiment, the gradient sensor 31 is provided, and the engine measurement unit 22B does not measure the internal loss of the engine 4 when the road surface gradient is equal to or higher than the gradient threshold value. Alternatively, even if the measurement is performed, the stop processing unit 22A excludes the measured value and sets the SOC threshold value. In other words, the internal loss of the engine 4 when the road surface gradient is equal to or higher than the threshold value does not affect the determination process of whether or not to stop the idling operation. Generally, when the road surface on which the vehicle 1 is located has a slope of a predetermined value or more, the oil level position of the engine oil in the crankcase changes, which affects the internal loss of the engine 4. Further, when there is a road surface gradient equal to or higher than a predetermined value, the control for stopping the idling operation is not performed. Therefore, with the above configuration, the stop processing unit 22A can obtain an appropriate SOC threshold value based on an appropriate internal loss.

(Modification 1)
FIG. 5 is a flowchart showing the ready-on processing of the modification 1 in the first embodiment. In the first modification, the update value of the SOC threshold value is calculated using the internal loss of the engine 4 measured a plurality of times in the past, and the point that the update value of the SOC threshold value is reset every driving cycle is changed. The driving cycle indicates a cycle in which one cycle is from the start of the system of the vehicle 1 to the stoppage. In the step of the ready-on processing of FIG. 5, the same steps as the step of FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the ready-on processing of the first modification, when the engine measuring unit 22B measures the internal loss of the engine 4 in step S6, the stop processing unit 22A determines whether it is an exception condition (step S11). As described above, the exception condition is a case where the road gradient is equal to or higher than the threshold value and the oil level is equal to or lower than the threshold value. Then, when it is determined in step S11 that it is an exception condition, or when it is determined in step S2 that it is not a cold start and the engine 4 is started in step S3, the stop processing unit 22A sets the SOC threshold value to the initial value. Return to (a value including a large determination margin set at the time of delivery) (step S12). Then, the process at the time of ready-on is terminated.

On the other hand, if it is determined in step S11 that the condition is not an exception, the engine measurement unit 22B stores the measured internal loss in the storage unit in association with the serial number for system activation (step S13). The memory here is executed so that it is saved even if the system is hibernated.

Subsequently, the stop processing unit 22A reads out the measured internal losses for the past plurality of times close to the present from the storage unit, and extracts the largest internal loss from the internal losses (step S14). Then, the SOC threshold value is calculated based on the extracted internal loss, and the SOC threshold value is updated with this value (step S15). In step S15, the method of calculating the SOC threshold is the same as the method of step S7 described above, only the internal loss used is different.

As described above, according to the vehicle 1 and the system control unit 22 of the modification 1, the SOC threshold value is calculated based on the largest internal loss among the internal losses of the engine 4 measured a plurality of times in the past. Therefore, even when the measurement error of the internal loss is rarely large, it is possible to suppress the inconvenience that the SOC threshold value is set small due to the measurement error and the engine 4 cannot be restarted after the idling operation is stopped.

Further, according to the vehicle 1 and the system control unit 22 of the modification 1, the SOC threshold value is reset every driving cycle. Therefore, even if an improper SOC threshold such as a larger SOC threshold is set for the measurement error of the internal loss and it becomes difficult to stop the idling operation, the system of the vehicle 1 can be restarted thereafter. , The improper SOC threshold can be returned to the initial value. Therefore, even if there is an error, it is possible to prevent the idling operation from being difficult to stop for a long time.

(Modification 2)
FIG. 6 is a flowchart showing the ready-on processing of the second modification in the first embodiment. In the second modification, the internal loss of the engine 4 measured when it is cold and the internal loss of the engine 4 measured when it is warm are used to update the SOC threshold value, and the temperature is determined by interpolation. The point of finding the SOC threshold using the internal loss of the time has been changed. The same steps as those in FIG. 4 are designated by the same reference numerals and detailed description thereof will be omitted.

In the ready-on processing of the second modification, after the startup processing of step S1, the engine measurement unit 22B determines whether the cold start condition or the hot start condition is satisfied (step S21). .. At the time of hot start, it is determined that the temperature of the coolant of the engine 4 is a high value indicating the time of hot start. Then, if the determination result in step S21 is NO, the system control unit 22 shifts the process to step S3, and if YES, advances the process to step S4.

When the engine measurement unit 22B measures the internal loss of the engine 4 in step S6, the engine measurement unit 22B associates it with, for example, the coolant temperature so that it can be identified whether the measurement is warm or cold. Then, the measured internal loss is stored in the storage unit (step S22). Then, the stop processing unit 22A performs the SOC threshold update processing as shown below (steps S23 to S26).

First, the stop processing unit 22A reads out the internal loss associated with the low coolant temperature and the internal loss associated with the high coolant temperature from the internal losses recently stored in the storage unit (step). S23). Next, the stop processing unit 22A estimates the temperature when the engine 4 is the coldest from the season during traveling or the outside air temperature (step S24). Further, the stop processing unit 22A interpolates the internal loss of the engine 4 when the estimated temperature in step S24 is reached from the internal loss in warm time and the internal loss in cold time read in step S23. Estimate (step S25). The interpolation process is a process in which the relationship between the temperature and the internal loss is estimated from the two known temperatures and the internal loss at the temperature, and the internal loss at the unknown temperature is obtained from the estimated relationship. For example, when the relationship between temperature and internal loss is almost a linear function, the internal loss of two known temperatures can be used to obtain the function to estimate the internal loss of other temperatures.

Then, the stop processing unit 22A calculates the SOC threshold value corresponding to the engine 4 having the internal loss based on the internal loss estimated in step S25, and updates the SOC threshold value (step S26). For the SOC threshold value of the second modification, a predetermined margin is added to the SOC of the auxiliary battery 8 that enables the engine 4 to be restarted even when the engine 4 has cooled to the estimated temperature in step S24 after the idling operation is stopped. It is the value that was set. The internal loss estimated in step S25 is the internal loss at the above estimated temperature, and correlates with the SOC of the auxiliary battery 8 that enables the restart of the engine 4 having the internal loss. The stop processing unit 22A holds in advance a function or a data table showing the relationship between the internal loss and the SOC threshold value corresponding to the internal loss, and uses these to obtain the SOC threshold value corresponding to the estimated internal loss. Ask. The above function or data table can be obtained by experiment or simulation. When the SOC threshold is updated, the ready-on processing ends.

In the second modification, in order to obtain the internal loss of the engine 4 at the time of warmth, an example of measuring the internal loss when the engine 4 is hot-started with the start of the system is shown. However, the internal loss of the engine 4 at the time of warmth may be acquired by using the method for measuring the internal loss of the second embodiment described later. The case where the engine 4 is hot-started when the system is started is rare, such as when the system of the vehicle 1 is stopped immediately after running and the system is started immediately after that, whereas the measurement of the second embodiment is performed. The method can measure the internal loss during warmth with high frequency.

As described above, according to the vehicle 1 and the system control unit 22 of the modification 2, the stop processing unit 22A is idling from the internal loss of the engine 4 when it is cold and the internal loss of the engine 4 when it is warm. The internal loss when the engine 4 is the coldest when the operation is stopped is obtained by interpolation processing. Then, the stop processing unit 22A sets the SOC threshold value based on this internal loss. Therefore, by the determination process using this SOC threshold value, it is possible to determine whether or not to stop the idling operation with a smaller determination margin. Therefore, even when the SOC of the auxiliary battery 8 is lowered to the vicinity of the SOC where there is little room for restarting the engine 4, the idling operation is often determined to be stopped, and the idling operation is stopped. You can have more opportunities.

(Embodiment 2)
FIG. 7 is a diagram showing a vehicle equipped with the idling stop control device according to the second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The vehicle 1R according to the second embodiment is an HEV (Hybrid Electric Vehicle). The vehicle 1R includes a drive wheel 2, an engine 4 that outputs power to the drive wheel 2, an auxiliary machine 5 for driving the engine 4, an ISG6 that starts or restarts the engine 4, and an ISG6 and an auxiliary machine 5. An auxiliary battery 8 that supplies electric power, a traveling motor 11 that outputs power to the drive wheels 2, an inverter 12 that drives the traveling motor 11, a traveling battery 13 that supplies driving power to the inverter 12, and an EV. (Electric Vehicle) An input clutch 9 that can disconnect the engine 4 from the drive shaft during traveling is provided. EV running means running only with the power of the traveling motor 11 without using the power of the engine 4. Engine running means running with the power of the engine 4.

The vehicle 1R further includes a driving operation unit 20 that receives a driver's driving operation, a traveling control unit 21 that controls the traveling of the vehicle 1, a system control unit 22R that controls the system of the vehicle 1, and a traveling road surface of the vehicle 1. A gradient sensor 31 for detecting a gradient, a rotation sensor 32 for detecting the rotational speed of the engine 4, a liquid temperature sensor 33 for measuring the temperature of the coolant of the engine 4, and an oil temperature sensor 34 for measuring the oil temperature of the engine 4. And a level sensor 35 for detecting the oil level of the engine oil.

The system control unit 22R includes a stop processing unit 22C that performs idling stop control, an engine measurement unit 22D that measures the internal loss of the engine 4, and an kinetic energy smaller than the starting energy of the engine 4 to give the engine 4 less than starting. The drive processing unit 22E that generates the motion of the engine 4 and the switching processing unit 22F that reduces the rotational resistance of the engine 4 when the engine 4 is not driven are included. The system control unit 22R functions as an idling stop control device.

The system control unit 22R and the stop processing unit 22C similarly execute the idling stop control process of FIG. 2 described in the first embodiment.

The input clutch 9 can be switched between a connected state and a disconnected state, and is switched and controlled by the system control unit 22R. The input clutch 9 can also be controlled to be connected in a half-clutch state.

<Measurement method of internal loss>
FIG. 8 is a time chart illustrating the measurement process of the internal loss of the engine according to the second embodiment.

In the second embodiment, the engine measurement unit 22D measures the internal loss of the engine 4 in cooperation with the drive processing unit 22E and the switching processing unit 22F. That is, as shown in FIG. 8, first, when the engine 4 is stopped (including during EV running), the switching processing unit 22F switches the auxiliary machine 5 to reduce the rotational resistance of the engine 4, and then switches the engine 4. , The drive processing unit 22E causes the engine 4 to generate a motion less than the start (period T11).

In the period T11, as a method in which the drive processing unit 22E causes the engine 4 to generate a motion less than the start, a method of causing the ISG 6 to output a drive force less than the start is applied. Alternatively, a method of connecting the input clutch 9 to the half-clutch state during EV traveling or coasting traveling may be applied.

In the period T11, a method of switching the throttle to fully open or a method of switching the valve in the exhaust pipe to fully open is applied to the method of reducing the rotational resistance of the engine 4 by the switching processing unit 22F. In addition, various methods may be applied, such as a method of lowering the oil level of the crankcase by transferring the engine oil to another place, a method of switching a mechanism for lowering the rotational resistance specially added to the engine 4, and the like.

The engine measurement unit 22D takes in the rotation speed of the engine 4 as data in the period T11. The rotation speed data for period T11 includes some parameters whose values change depending on the internal loss of the engine 4. For example, the maximum rotation speed within the period T11, the rate of change when the rotation speed rises or falls (average value of inclination, etc.), the time until the rotation speed rises to a predetermined value, and the rotation speed is zero from the predetermined value. Each parameter, such as the time to fall to, has a correlation with the internal loss of the engine 4. The engine measurement unit 22D holds in advance a function or a data table showing the relationship between the above parameters and the internal loss of the engine 4, and calculates the internal loss of the engine 4 from the above parameters using these functions. The above function or data table can be obtained by experiment or simulation.

After the control of the period T11 for measuring the internal loss of the engine 4, the switching for reducing the rotational resistance of the engine 4 with respect to the auxiliary machine 5 is returned (timing t11), and the engine 4 is stopped (timing t12).

The engine measurement unit 22D measures the internal loss by aligning the environment of the engine 4. This is to measure the internal loss by excluding factors that change due to the environment. As the environmental condition in which the engine measurement unit 22D executes the measurement process in the second embodiment, the warm condition is applied. That is, it is a condition that the coolant temperature of the engine 4 is within a predetermined range corresponding to the warm time. Since the rotational resistance of the engine 4 is low during warm weather, labor saving can be achieved when measuring the internal loss due to the above environmental conditions.

<SOC threshold update process>
FIG. 9 is a flowchart showing the SOC threshold value update process executed by the system control unit of the second embodiment. The SOC threshold update process is started, for example, at an arbitrary timing during system startup. When the SOC threshold value update process is started, first, the engine measurement unit 22D determines whether or not the engine 4 is stopped (step S41), and whether or not the coolant temperature is within a predetermined range indicating warm time. The determination process (step S42) and the determination process (step S43) of whether or not the SOC of the auxiliary battery 8 is equal to or higher than the threshold value indicating the medium level are performed. If any of steps S41 to S43 is NO, the system control unit 22R ends the SOC threshold value update process as it is without updating the SOC threshold value.

On the other hand, if all of steps S41 to S43 are YES, the system control unit 22R prohibits the restart of the engine 4 so that the engine 4 does not restart during the measurement of the internal loss (step S44). Subsequently, the switching processing unit 22F performs switching to reduce the rotational resistance of the engine 4 (step S45), and the drive processing unit 22E gives the engine 4 kinetic energy smaller than the starting energy to cause the engine 4 to perform less than starting motion. Generate (step S46). Then, the engine measurement unit 22D takes in the rotation speed data of the engine 4 during the exercise period, and measures the internal loss of the engine 4 from the maximum rotation speed during this period by the method described above (step S47). When the internal loss is measured, the system control unit 22R releases the prohibition of restarting the engine 4 (step S48).

After the internal loss is measured in step S46, the stop processing unit 22C next calculates the SOC threshold value based on the measured internal loss, and updates the SOC threshold value with the calculated value (step S49). The internal loss measured in step S47 is the internal loss when it is warm, but it is the internal loss when the temperature of the engine 4 is substantially constant. Therefore, there is a correlation between this internal loss and the SOC of the auxiliary battery 8 required for restarting when the engine 4 having this internal loss is cold. Therefore, the stop processing unit 22C calculates in step S49 the SOC of the auxiliary battery 8 required for restarting the engine 4 having the current internal loss in a cold state from the function or the data table showing this relationship. Further, the stop processing unit 22C calculates the SOC threshold value by adding a margin to the calculated SOC. Then, when the SOC threshold value is updated, the SOC threshold value update process ends.

As described above, according to the vehicle 1R and the system control unit (idling stop control device) 22R of the second embodiment, the engine measurement unit 22D measures the internal loss of the engine 4. Then, the stop processing unit 22C determines the SOC threshold value based on the measured internal loss of the engine 4, and determines whether or not to stop the idling operation based on the comparison between the SOC of the auxiliary battery 8 and the SOC threshold value. I do. In other words, the stop processing unit 22C performs a determination process of whether or not to stop the idling operation based on the measured internal loss of the engine 4 and the SOC of the auxiliary battery 8. In this way, by reflecting the measured value of the internal loss in the above determination process, the determination margin of the determination process is made smaller than the case where the above determination process is performed assuming the case where the internal loss is the largest. can. Therefore, even when the SOC of the auxiliary battery 8 is lowered to the vicinity of the SOC where there is little room for restarting the engine 4, the idling operation is often determined to be stopped, and the idling operation is stopped. Opportunities can be increased.

Further, according to the vehicle 1R and the system control unit 22R of the second embodiment, the drive processing unit 22E causes the engine 4 to generate a motion less than the start, and the engine measurement unit 22D measures the internal loss of the engine 4 from the motion at this time. do. Therefore, it is possible to increase the situation in which the internal loss of the engine 4 can be measured as compared with the case of measuring at the start of the engine 4, and further, it is possible to increase the situation in which the internal loss in the warm state can be measured. Further, when the internal loss is measured, the drive processing unit 22E generates a motion less than the starting motion in the engine 4, so that the energy consumption can be reduced and the fuel consumption of the vehicle 1 can be suppressed from being reduced due to the measurement of the internal loss.

Further, according to the vehicle 1R and the system control unit 22R of the second embodiment, when measuring the internal loss of the engine 4, the switching processing unit 22F performs switching to reduce the rotational resistance of the engine 4. Therefore, it is possible to reduce the energy consumption for measuring the internal loss and further suppress the reduction in the fuel consumption of the vehicle 1 for measuring the internal loss.

Further, according to the vehicle 1R and the system control unit 22R of the second embodiment, the condition that the engine measuring unit 22D measures the internal loss of the engine 4 is that the SOC of the auxiliary battery 8 is equal to or higher than the threshold value indicating a medium level. (Step S43 of SOC threshold update processing) is included. Under this condition, it is possible to suppress a situation in which the power of the auxiliary battery 8 is consumed for measuring the internal loss and the idling operation is not stopped due to insufficient SOC in the subsequent idling stop control.

Further, according to the vehicle 1R and the system control unit 22R of the second embodiment, the engine measurement unit 22D determines whether the environment of the engine 4 meets the conditions, and if they match (for example, the coolant temperature is warm). When the time is within a predetermined range: (see step S42 in FIG. 9), the internal loss is measured. The internal loss of the engine 4 includes an element that changes depending on the environment such as cold time and warm time. Therefore, by making measurements in the same environment, the engine measuring unit 22D can measure the internal loss of the engine 4 by eliminating the elements that change depending on the environment. With the internal loss measured in this way, the stop processing unit 22C can set an appropriate SOC threshold value. Further, as the environment for measuring the internal loss, the warm environment of the engine 4 is set, and since this environment is the environment in which the rotational resistance of the engine 4 is lowered, the engine 4 is less than the starting environment. It is possible to save labor when exerting exercise.

(Modification 3)
FIG. 10 is a flowchart showing the SOC threshold value update process of the modification 3 in the second embodiment. In the modification 3, the SOC is obtained by using the internal loss at a certain temperature obtained by the interpolation process from the internal loss of the engine 4 measured when it is cold and the internal loss of the engine 4 measured when it is warm. The point at which the threshold is calculated has been changed. The same steps as those in FIG. 9 are designated by the same reference numerals and detailed description thereof will be omitted.

In the SOC threshold value update process of the third modification, if YES is determined in the determination process of step S41, the engine measurement unit 22D indicates that the coolant temperature is within the first range indicating warm time, or when it is cold. (Step S51), and if the determination result is YES, the process proceeds to step S43. As a result, in the modification 3, the internal loss measurement processing of steps S44 to S48 is executed when the engine 4 is warm and when it is cold. When the internal loss is measured, the engine measurement unit 22D stores the measured internal loss by associating it with, for example, the coolant temperature so that it can be identified whether the measurement is warm or cold. Store in the unit (step S52).

When the internal loss is measured, the stop processing unit 22C performs the SOC threshold update processing in steps S53 to S56. First, the stop processing unit 22C has an internal loss associated with the cold coolant temperature and an internal loss associated with the warm coolant temperature from the internal losses recently stored in the storage unit. Read out the loss (step S53). Then, the stop processing unit 22C estimates the temperature when the engine 4 is the coldest from the season during traveling or the outside air temperature (step S54). Further, the stop processing unit 22C interpolates the internal loss of the engine 4 when the estimated temperature in step S54 is reached from the internal loss in warm time and the internal loss in cold time read in step S53. Estimate (step S55). Then, based on the internal loss estimated in step S55, the SOC threshold value corresponding to the engine 4 having the internal loss is calculated, and the SOC threshold value is updated (step S56). For the SOC threshold value of the modification 3, a predetermined margin is added to the SOC of the auxiliary battery 8 that enables the engine 4 to be restarted even when the engine 4 has cooled to the estimated temperature in step S54 after the idling operation is stopped. It is the value that was set. The internal loss estimated in step S55 is the internal loss at the above estimated temperature, and correlates with the SOC of the auxiliary battery 8 that enables the restart of the engine 4 having the internal loss. The stop processing unit 22C obtains an SOC threshold value corresponding to the estimated internal loss by using a function or a data table showing the relationship between the internal loss and the SOC threshold value corresponding to the internal loss. The above function or data table is obtained by experiment or simulation and is given to the stop processing unit 22C in advance. When the SOC threshold is updated, the SOC threshold update process ends.

In the modified example 3, the internal loss of the engine 4 when it is cold is also measured by the SOC threshold update process executed at an arbitrary timing. However, the internal loss of the engine 4 in the cold state may be measured by the process in the ready-on state shown in the first embodiment.

As described above, according to the vehicle 1R and the system control unit 22R of the modification 3, the stop processing unit 22C is idling from the internal loss of the engine 4 when it is cold and the internal loss of the engine 4 when it is warm. The internal loss when the engine 4 is the coldest when the operation is stopped is obtained by interpolation processing. Then, the stop processing unit 22C sets the SOC threshold value based on this internal loss. Therefore, by the determination process using this SOC threshold value, it is possible to determine whether or not to stop the idling operation with a smaller determination margin. Therefore, even when the SOC of the auxiliary battery 8 is lowered to the vicinity of the SOC where there is little room for restarting the engine 4, it is often determined that the idling operation is stopped, and there is an opportunity to stop the idling operation. Can be increased.

Although each embodiment has been described above, the present invention is not limited to the above embodiment, and the examples shown in the embodiments can be appropriately modified without departing from the spirit of the invention.

1 vehicle 2 drive wheel 4 engine 5 auxiliary equipment 6 ISG
8 Auxiliary battery 8a Management unit 9 Input clutch 11 Driving motor 12 Inverter 13 Driving battery 20 Driving operation unit 21 Driving control unit 22, 22R System control unit (idling stop control device)
22a Soak timer 22A Stop processing unit 22B Engine measurement unit 22C Stop processing unit 22D Engine measurement unit 22E Drive processing unit 22F Switching processing unit 30 Vehicle speed sensor 31 Gradient sensor 32 Rotation sensor 33 Liquid temperature sensor 34 Oil temperature sensor 35 Level sensor

Claims (5)

An idling stop control device mounted on a vehicle having an engine, a starting motor for restarting the engine, and an auxiliary battery for supplying electric power to the starting motor.
The engine measurement unit that measures the internal loss of the engine,
Based on the charge state of the auxiliary battery and the internal loss measured by the engine measuring unit, a process of determining whether to stop the idling operation of the engine is performed, and when it is determined to stop, the idling operation is performed. And the stop processing unit to stop
A drive processing unit that applies kinetic energy smaller than the starting energy to the engine to generate motion less than starting in the engine.
Equipped with
The engine measuring unit is an idling stop control device characterized in that the internal loss is measured based on the motion less than the starting. It is equipped with a switching processing unit that lowers the rotational resistance of the engine.
The idling stop control device according to claim 1, wherein the engine measuring unit reduces the rotational resistance by the switching processing unit when measuring the internal loss. The idling stop according to claim 1 or 2, wherein the condition for the engine measuring unit to measure the internal loss includes a condition that the auxiliary battery has a charge amount equal to or higher than a threshold value. Control device. One of claims 1 to 3, wherein the engine measuring unit determines whether the environment of the engine meets the conditions, and measures the internal loss when the environment is met. The idling stop control device described in. The engine measuring unit measures the internal loss when the environment of the engine is warm and cold.
The stop processing unit is at a temperature different from that of the warm and the cold based on the internal loss measured during the warm and the internal loss measured during the cold. The idling stop control device according to any one of claims 1 to 4, wherein the internal loss of the engine is estimated and the determination process is performed based on the estimated internal loss.

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