JP7054370B2 - Control device - Google Patents

Description

The present invention relates to a control device that controls an engine.

Examples of the auxiliary machine driven by the engine of the vehicle include a compressor that compresses and discharges the refrigerant during the refrigeration cycle. In Patent Document 1, a cool storage device is provided in the refrigeration cycle, and the air blown into the vehicle interior during coasting, vehicle stoppage, or other engine stoppage is stored in the cool storage device. A system for carrying out cooling, so-called cold storage cooling, is disclosed.

In the technique described in Patent Document 1, when the cold storage cooling is performed while the engine is stopped, the drive stop condition of the compressor is set based on the difference in the duration between the coasting running and the vehicle stop. Specifically, in the case of coasting for a short period of time, the compressor is controlled to stop while the temperature of the air cooled by the regenerator is below the first temperature, and in the case of a long-term vehicle stoppage, the compressor is stopped. The compressor is controlled to be stopped while the temperature of the air cooled by the regenerator is higher than the first temperature and is equal to or lower than the second temperature. According to this, the compressor can be stopped for a long period of time while the temperature inside the vehicle is suppressed from rising during short-term coasting, while maintaining the comfort inside the vehicle. , The fuel efficiency of the vehicle can be improved.

Japanese Unexamined Patent Publication No. 2016-203927

It is desirable to improve the fuel efficiency of the vehicle while the engine is operating by using the cold storage stored in the cold storage. For example, it is possible to improve the fuel efficiency of the vehicle while the engine is operating by performing the cold storage cooling while the engine is operating to cut the fuel and stopping the compressor.

The more cold storage used during engine operation, the better the fuel efficiency of the vehicle during engine operation. On the other hand, if a large amount of cold storage is used during engine operation, the amount of cold storage stored in the cold storage device decreases. If the cold storage stored in the cold storage is excessively reduced, the compressor cannot be continuously stopped when the engine is switched to the stopped state, and the fuel efficiency of the vehicle is deteriorated when the engine is stopped. Occurs. There is a demand for a technique for effectively utilizing the cold storage stored in the cold storage device to improve the fuel efficiency of the vehicle while the engine is stopped and the engine is operating.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a control device capable of improving the fuel efficiency of a vehicle.

The present invention is applied to a vehicle equipped with a refrigerating cycle including a compressor driven by rotation of an engine output shaft and a cold storage provided in a refrigerant path, and the probability of occurrence of engine stop during operation of the vehicle. A generation probability acquisition unit for acquiring the above, and a control unit for stopping the compressor during the engine operation of the vehicle based on the occurrence probability at the time of cooling the vehicle interior by the refrigeration cycle.

It is possible to improve the fuel efficiency of the vehicle by cutting the fuel and stopping the compressor by performing cold storage and cooling while the engine of the vehicle is operating. However, if the amount of cold storage used during engine operation is large and the amount of cold storage stored in the regenerator is excessively reduced, the compressor cannot be continuously stopped when the engine is switched to the stopped state, and the engine cannot be stopped. The fuel efficiency of the vehicle when stopped deteriorates.

In the control device of the present invention, the probability of occurrence of engine stop during vehicle operation is acquired, and the compressor is stopped during vehicle engine operation based on this probability of occurrence when cooling the vehicle interior by a refrigeration cycle. Let me. In this case, when the probability of occurrence of engine stop is low, the fuel efficiency of the vehicle during engine operation can be improved by enabling cold storage and cooling with the compressor stopped during engine operation. Further, when the probability of occurrence of engine stop is high, the compressor can be kept in the stopped state while the engine is stopped by preventing the compressor from stopping while the engine is operating. As a result, it is possible to improve the fuel efficiency of the vehicle while the engine is stopped and the engine is operating.

The block diagram which shows the outline of the engine control system. A flowchart showing a cold storage amount control process. A flowchart showing the correction process. The figure which shows the correspondence map. The figure which shows the relationship between the average speed and the low speed period ratio, and the decrease change amount. A time chart showing an example of the cold storage amount control process of one embodiment. The figure which shows the negative torque in the case where the fuel cut state is an on state and the case where it is an off state. The figure which shows the characteristic map. A time chart showing an example of a cold storage amount control process of another embodiment.

Hereinafter, the engine control system of the vehicle 100 to which the control device of one embodiment is applied will be described with reference to the drawings. As shown in FIG. 1, the vehicle 100 includes an engine 10 as an internal combustion engine and an ECU 40 as a control device.

The engine 10 is an in-cylinder injection type 4-cycle gasoline engine mounted on the vehicle 100. Specifically, the engine 10 is a 4-cylinder engine including four cylinders. Each cylinder of the engine 10 mounted on the vehicle 100 is provided with a fuel injection valve 11 for supplying fuel to the combustion chamber of the engine 10.

The energy generated by the combustion of the fuel is taken out as the rotational power of the crank shaft 13 of the engine 10. This rotational power is transmitted to drive wheels (not shown) of the vehicle 100 via the transmission 14. In this embodiment, the crank shaft 13 corresponds to the "engine output shaft".

A starter 20 is connected to the crank shaft 13. The starter 20 is started by being supplied with electric power from the battery 21 by turning on an ignition switch (not shown), and gives an initial rotation to the crank shaft 13 to start the engine 10.

The alternator 22 is a generator that is driven by the rotational energy of the crank shaft 13 to generate electricity. That is, the alternator 22 is a recovery device that recovers the rotational energy of the engine 10 as electrical energy. The pulley 24 mechanically connected to the drive shaft 23 of the alternator 22 is mechanically connected to the crank shaft 13 via the belt 15 and the crank pulley 16. The alternator 22 can adjust the amount of power generation by adjusting the exciting current flowing through the rotor coil of the alternator 22. The battery 21 is a storage battery that stores the electric power generated by the alternator 22. The alternator 22 and the battery 21 constitute a power storage system 29. The ECU 40 acquires the stored amount Qe of the battery 21 from the battery 21, and controls the amount of power generation by the alternator 22 so that the stored amount Qe is within an appropriate range.

The vehicle 100 is equipped with a cooling system that cools the interior of the vehicle. This cooling system includes a compressor 30 that sucks and discharges the refrigerant to circulate the refrigerant in the refrigeration cycle 39, a condenser 31, a receiver 32, an expansion valve 33, an evaporator 34, and the like provided in the refrigerant path 31a. It is composed of.

The compressor 30 is driven by the rotational energy of the crank shaft 13, and the discharge capacity of the refrigerant can be continuously variably set by the energization operation of the electromagnetically driven control valve (CV) 30a provided in the compressor 30. It is a capacitive compressor. The pulley 38 mechanically connected to the drive shaft 37 of the compressor 30 is mechanically connected to the crank shaft 13 via the belt 15 and the crank pulley 16. Under the condition that the rotational power of the crank shaft 13 is transmitted to the compressor 30, the discharge capacity is adjusted by the operation of energizing the CV 30a. In the compressor 30, a state in which the discharge capacity is larger than 0 is a state in which the compressor 30 is driven, and a state in which the discharge capacity is 0 is a state in which the compressor 30 is stopped.

The condenser 31 is a member that exchanges heat between the air (outside air) blown from a fan (not shown) that is rotationally driven by a DC motor or the like and the refrigerant discharged and supplied from the compressor 30. The receiver 32 is provided to separate the refrigerant flowing from the capacitor 31 into gas and liquid, temporarily store the separated liquid refrigerant, and supply only the liquid refrigerant to the downstream side. The liquid refrigerant stored in the receiver 32 is rapidly expanded by the expansion valve 33 to be atomized. The atomized refrigerant is supplied to the evaporator 34 that cools the air blown into the vehicle interior.

In the evaporator 34, a part or all of the refrigerant is vaporized by heat exchange between the air blown from the fan (Eva fan) 35 that is rotationally driven by a DC motor or the like and the atomized refrigerant. As a result, the air blown from the EVA fan 35 is cooled, and the cooled air is blown into the vehicle interior, so that the vehicle interior can be cooled. A refrigerant temperature sensor 34a for detecting the refrigerant temperature is provided in the immediate vicinity of the outlet of the evaporator 34. Further, the refrigerant flowing out of the evaporator 34 is sucked into the suction port of the compressor 30.

In the refrigeration cycle 39 of the present embodiment, the cool storage device 36 is attached to the evaporator 34. The cold storage device 36 is configured by enclosing a cold storage agent such as paraffin that stores the heat of the refrigerant. For example, the predetermined stop condition is during so-called idle stop control in which the engine 10 is automatically stopped when a predetermined stop condition is satisfied during idle operation, or during coasting running with the clutch device provided between the engine 10 and the transmission 14 in a disengaged state. When the condition is satisfied, the compressor 30 is automatically stopped by the automatic stop of the engine 10 during the engine stop such as the so-called coasting running control in which the engine 10 is automatically stopped. When the cooler 36 is attached, the air blown from the Eva fan 35 and the cooler 36 exchange heat under the condition that the compressor 30 is stopped, so that the blown air is cooled and cooled. By sending the air to the passenger compartment, it becomes possible to cool the passenger compartment, that is, to store and cool the passenger compartment. The cold storage in the cold storage device 36 is performed, for example, by operating the compressor 30 in excess with respect to a predetermined cooling request amount. That is, the compressor 30 is a recovery device that recovers the rotational energy of the engine 10 as heat energy.

The ECU 40 has an A / C switch operation signal operated by the vehicle occupant, which is a signal for driving the compressor 30 to cool the vehicle interior, or an operation signal for the target temperature setting switch operated by the vehicle occupant. Therefore, a signal for setting a target temperature in the vehicle interior, a detection signal for the vehicle interior temperature sensor for detecting the vehicle interior temperature, a refrigerant temperature sensor 34a, and the like are input. The ECU 40 operates various devices such as the EVA fan 35 and the CV30a by executing various control programs stored in the ROM in response to these inputs. Then, by operating these various devices, the drive control of the compressor 30 and the cooling control of the vehicle interior are performed.

In the drive control of the compressor 30, the cold storage amount Qc of the cold storage device 36 can be adjusted by adjusting the energization amount flowing through the CV 30a of the compressor 30. The ECU 40 calculates the cold storage amount Qc of the cold storage device 36 based on the surplus operation amount of the compressor 30 surplus operation with respect to the cooling request amount. The ECU 40 controls the energization amount of the CV 30a so that the cold storage amount Qc is within an appropriate range. Specifically, the ECU 40 energizes the CV 30a when the cold storage amount Qc drops to the lower limit threshold value Qs1 (see FIG. 6) during engine operation, operates the compressor 30, and stores the rotational energy of the crank shaft 13. Store as quantity Qc. Further, when the cold storage amount Qc rises to the upper limit threshold value Qs2 (see FIG. 6) larger than the lower limit threshold value Qs1, the ECU 40 stops the energization of the CV 30a and stops the operation of the compressor 30.

Further, the vehicle 100 is provided with a hydraulically driven brake actuator 80. The brake actuator 80 generates a brake torque Tb according to the amount of brake operation by the driver, and reduces the rotational power of the crank shaft 13.

As is well known, the ECU 40 is mainly composed of a microcomputer including a CPU, ROM, RAM and the like. Detection signals are input to the ECU 40 from various sensors and the like. In addition to the above-mentioned sensors, FIG. 1 shows a vehicle speed sensor 25 that detects a vehicle speed Vm, an image pickup device 26 and a radar device 27 that detect an object existing around the vehicle, and a navigation device 28. The ECU 40 executes combustion control of the engine 10 such as fuel injection control by the fuel injection valve 11 by executing various control programs stored in the ROM in response to the above input. In this embodiment, the ECU 40 corresponds to the "control device".

The image pickup device 26, the radar device 27, and the navigation device 28 will be described. The image pickup device 26 is an in-vehicle camera, and is configured by using a CCD camera, a CMOS image sensor, a near-infrared camera, and the like. The image pickup apparatus 26 photographs the surrounding environment including the driving road of the own vehicle, generates image data representing the photographed image, and sequentially outputs the image data to the ECU 40. The image pickup device 26 is installed near the upper end of the windshield of the own vehicle, for example, and photographs a region extending within a predetermined angle toward the front of the vehicle around the image pickup axis. The image pickup device 26 may be a monocular camera or a stereo camera.

The radar device 27 is a detection device that detects an object by transmitting an electromagnetic wave as a transmission wave and receiving the reflected wave, and is configured by using a millimeter wave radar or the like. The radar device 27 is attached to the front portion of the own vehicle, for example, and scans a region extending over a range of a predetermined angle toward the front of the vehicle by a radar signal. Then, the received data is created based on the period from the transmission of the electromagnetic wave toward the front of the vehicle to the reception of the reflected wave. The received data includes ranging data. The ranging data includes information on the direction in which the object is located, the distance to the object, and the relative velocity. The information of the received data created by the radar device 27 is sequentially output to the ECU 40.

The navigation device 28 acquires map data from a map storage medium that records road map data and various information, and calculates the current position of the vehicle 100 based on a GPS signal or the like received via a GPS antenna. Further, the navigation device 28 controls to display the current location of the own vehicle, controls to guide the vehicle front route from the current location to the destination, and controls to notify that a traffic jam or the like has occurred in the vehicle front route. I do.

Further, the ECU 40 implements recovery control for recovering the rotational energy of the engine 10 during engine operation such as deceleration of the vehicle 100. That is, when a predetermined energy recovery request is acquired, the ECU 40 drives the alternator 22 and the compressor 30 by the rotational driving force of the crank shaft 13, and controls to generate a negative torque Tn. As a result, the rotational energy of the engine 10 is converted into thermal energy and stored in the cold storage 36, and at the same time, it is converted into electric energy and stored in the battery 21.

Here, the negative torque Tn is a torque that acts in the direction opposite to the rotation direction of the crank shaft 13 of the engine 10, and includes a power generation torque Te, a drive torque Tc, and a loss torque Tl. The power generation torque Te is the torque generated by driving the alternator 22, and the drive torque Tc is the torque generated by driving the compressor 30. Further, the loss torque Tl is a torque generated by vibration, friction, or the like in the engine 10, and includes a pump loss which is a pressure loss in the intake pipe of the engine 10.

By the way, when the cold storage device 36 is provided in the refrigerant path 31a in the refrigeration cycle 39, the fuel consumption Ef of the vehicle 100 in which the engine is stopped is determined by using the cold storage amount Qc stored in the cold storage device 36 as in the prior art. Can be improved. Further, it is desired to improve the fuel consumption Ef of the vehicle 100 during engine operation by using the cold storage amount Qc stored in the cold storage device 36. For example, by performing cold storage and cooling while the engine is operating, the fuel can be cut and the compressor 30 can be stopped, and the fuel consumption Ef of the vehicle 100 during the engine operation can be improved.

The larger the cold storage amount Qc used during engine operation, the better the fuel efficiency Ef of the vehicle 100 during engine operation. On the other hand, if the amount of cold storage Qc used during engine operation is large, the amount of cold storage Qc stored in the cold storage device 36 decreases. If the amount of cold storage Qc stored in the cold storage device 36 is excessively reduced, the compressor 30 cannot be continuously stopped when the engine is switched to the stopped state, and the vehicle 100 while the engine is stopped cannot be continued. There arises a problem that fuel efficiency Ef deteriorates.

The ECU 40 of the present embodiment implements a cold storage amount control process in order to solve the above problem. In the cold storage amount control process, the probability of occurrence of engine stop during the operation of the vehicle 100 is acquired, and when the cold storage cooling is performed, the compressor 30 is stopped during the operation of the engine of the vehicle 100 based on this probability of occurrence. In this case, when the probability of occurrence of engine stop is low, the fuel efficiency Ef of the vehicle 100 during engine operation can be improved by enabling cold storage and cooling with the compressor 30 stopped during engine operation. Can be done. Further, when the probability of occurrence of engine stop is high, the compressor 30 can be maintained in the stopped state while the engine is stopped by not stopping the compressor 30 while the engine is operating. As a result, it is possible to improve the fuel efficiency Ef of the vehicle 100 while the engine is stopped and the engine is operating.

FIG. 2 shows a flowchart of the cold storage amount control process of the present embodiment. This control process is repeatedly executed by the ECU 40 at a predetermined cycle, for example, during the operation of the vehicle 100.

When the cold storage amount control process is started, first, in step S10, it is determined whether the vehicle 100 is in operation. Specifically, it is determined whether the ignition switch of the vehicle 100 is on.

If an affirmative determination is made in step S10, it is determined in the following step S12 whether to carry out cold storage cooling. Specifically, it is determined whether the A / C switch has been operated by the vehicle occupant.

If a negative determination is made in step S12, the cold storage amount control process is terminated. On the other hand, if an affirmative determination is made in step S12, it is determined in step S14 whether the compressor 30 is being driven.

If the affirmative determination is made in step S14, it is determined in step S16 whether to stop the compressor 30 based on the energy efficiency. Here, the engine efficiency is the efficiency of the engine 10 determined by using the engine rotation speed Ne and the negative torque Tn as parameters (see FIG. 8). In the vehicle 100, by stopping the compressor 30, the engine efficiency during the engine operation of the vehicle 100 changes. Therefore, the engine efficiency can be adjusted by stopping the compressor 30.

If the engine efficiency is reduced by stopping the compressor 30, a negative determination is made in step S16. In this case, the cold storage amount control process is terminated. On the other hand, when the engine efficiency is improved by stopping the compressor 30, a positive determination is made in step S16. In this case, the average velocity Vav is calculated in the following step S18. Here, the average speed Vav is an average value of the vehicle speed Vm within the predetermined period Yt, and is calculated based on the vehicle speed Vm acquired by using the vehicle speed sensor 25. Therefore, in step S18, it can be said that the average speed Vav is acquired based on the vehicle speed Vm.

In step S20, the forward course information If is acquired. Here, the forward course information If is information indicating the traffic conditions in front of the vehicle and in the front course of the vehicle. When the vehicle is running, the vehicle 100 may be forced to decelerate due to the traffic conditions in the front path of the vehicle, and the engine may be stopped. Further, when the vehicle is traveling, the driver may intend to accelerate the vehicle 100 and the engine may be in operation depending on the traffic condition of the vehicle ahead. In this embodiment, the process of step S20 corresponds to the "traffic information acquisition unit".

Specifically, as the forward course information If, information on the preceding vehicle traveling in front of the vehicle and information on traffic lights and railroad crossings existing in front of the vehicle are acquired from the image pickup device 26 and the radar device 27. Further, as the forward course information If, information on the course and traffic congestion of the vehicle forward course is acquired from the navigation device 28.

In step S22, the low speed period ratio Pt is calculated based on the forward course information If acquired in step S20. Here, the low-speed period ratio Pt indicates the ratio of the low-speed period Yl in which the vehicle speed Vm is slower than the reference speed Vk within the predetermined period Yt. The low speed period ratio Pt is expressed as (Equation 1).

Pt = Yl / Yt × 100 ... (Equation 1)
The low speed period ratio Pt is calculated based on the forward course information If. Therefore, in step S22, it can be said that the low-speed period ratio Pt is acquired based on the forward course information If. In this embodiment, the processes of steps S18 and S22 correspond to the "occurrence probability acquisition unit".

In the following step S24, it is determined whether the probability of engine stop occurring during the operation of the vehicle 100 is low based on the average speed Vav and the low speed period ratio Pt calculated in steps S18 and S22. Specifically, it is determined whether the average speed Vav is faster than the reference speed Vk, and whether the low speed period ratio Pt is higher than the reference ratio Pk.

When the average speed Vav is in a high-speed running state faster than the reference speed Vk and the low-speed period ratio Pt is a low ratio lower than the reference ratio Pk, a negative determination is made in step S24. In this case, since it is determined that the probability of engine stop of the vehicle 100 is high, normal control is performed in step S36. In normal control, the lower limit threshold value Qs1 is controlled based on the operating state of the engine 10. The lower limit threshold Qs1 based on the operating state of the engine 10 can be calculated by using the engine rotation speed Ne, the engine load such as the intake air amount to the engine 10 and the intake negative pressure.

On the other hand, when the average speed Vav is a low-speed running state slower than the reference speed Vk, or the low-speed period ratio Pt is a high ratio higher than the reference ratio Pk, a positive determination is made in step S24. In this case, since it is determined that the probability of occurrence of the engine stop of the vehicle 100 is low, reduction control (S26 to S32) for reducing and changing the lower limit threshold value Qs1 is performed.

In the reduction control, first, in step S26, the day of the week information Iw and the time zone information It in the current driving cycle are acquired. Here, the day of the week information Iw is the information of the day of the week including the timing when the ignition switch of the vehicle 100 is turned on in the current driving cycle, and the time zone information It is the information of the time zone including the timing. In addition, instead of the timing when the ignition switch is turned on, the timing when the ignition switch is turned off may be used. In the present embodiment, the process of step S26 corresponds to the "time information acquisition unit".

In the following step S28, the reduction change amount Qg is set by referring to the corresponding map MP stored in advance in the storage unit 42 of the ECU 40. Here, the decrease change amount Qg is a change amount for changing the lower limit threshold value Qs1 to the smaller side, and is an amount for increasing to the negative side. The storage unit 42 is, for example, a non-transitional substantive recording medium other than ROM (for example, a non-volatile memory other than ROM). In this embodiment, the reduced change amount Qg corresponds to the "change amount".

The correspondence map MP is correspondence map information in which the reduction change amount Qg is predetermined in correspondence with the day of the week information Iw and the time zone information It. As shown in FIG. 4, in the corresponding map MP, the reduction change amount Qg is predetermined for each time zone of each day of the week. In step S28, in the corresponding map MP, the decrease change amount Qg associated with the day of the week information Iw and the time zone information It acquired in step S26 is specified. In this embodiment, the correspondence map MP corresponds to "correspondence information".

In the corresponding map MP, the decrease change amount Qg is defined as a fluctuation amount that varies depending on the average speed Vav and the low speed period ratio Pt. For example, as shown in FIG. 5, the decrease change amount Qg has a relationship that increases as the average speed Vav is faster or the low speed period ratio Pt is lower, that is, as the probability of engine stop occurring is lower. In step S28, the decrease change amount Qg corresponding to the average velocity Vav and the low speed period ratio Pt calculated in steps S18 and S22 is specified, and the decrease change amount Qg is set. The slope of the decrease change amount Qg with respect to the average speed Vav and the low speed period ratio Pt may be different or the same for each day of the week information Iw and time zone information It.

In step S30, it is determined whether the change permission mode is selected. In the vehicle 100, the driver can select either a change permission mode or a change prohibition mode. Here, the change permission mode is a mode for permitting a decrease change of the lower limit threshold value Qs1 in order to continue stopping the compressor 30 while the engine of the vehicle 100 is operating. By permitting the reduction change of the lower limit threshold value Qs1, the range of the cold storage amount Qc that can stop the compressor 30 while the engine of the vehicle 100 is operating is expanded, and the compressor 30 is continuously stopped while the engine of the vehicle 100 is operating. To.

Further, the change prohibition mode is a mode for prohibiting a decrease change of the lower limit threshold value Qs1 in order to continue stopping the compressor 30 while the engine of the vehicle 100 is stopped. By prohibiting the decrease change of the lower limit threshold value Qs1, it is suppressed that the cold storage amount Qc at the start of engine stop of the vehicle 100 is excessively reduced, and the compressor 30 is continuously stopped while the engine of the vehicle 100 is stopped. The engine. In this embodiment, the process of step S24 corresponds to the "selection unit".

Therefore, the change permission mode can be said to be a mode in which the improvement of the fuel consumption Ef of the vehicle 100 while the engine of the vehicle 100 is operating is prioritized over the improvement of the fuel consumption Ef of the vehicle 100 while the engine of the vehicle 100 is stopped. Further, the change prohibition mode can be said to be a mode in which the improvement of the fuel consumption Ef of the vehicle 100 while the engine of the vehicle 100 is stopped is prioritized over the improvement of the fuel consumption Ef of the vehicle 100 while the engine of the vehicle 100 is operating.

If the affirmative determination is made in step S30, that is, the reduction change is executed on condition that the change permission mode is selected. The selection of the change permission mode is performed on the condition that it is determined that the probability of occurrence of the engine stop of the vehicle 100 is low. Therefore, it can be said that the reduction change is carried out on condition that the probability of occurrence of the engine stop of the vehicle 100 is low. Specifically, in step S32, the lower limit threshold value Qs1 is reduced by the amount of reduction change Qg set in step S28. In this embodiment, the process of step S32 corresponds to the "changed portion".

On the other hand, if a negative determination is made in step S30, that is, on condition that the change prohibition mode is selected, the process proceeds to step S30 without reducing and changing the lower limit threshold value Qs1. As a result, the reduction change of the lower limit threshold value Qs1 is prohibited.

When the processing of steps S32 and S36 is completed, the compressor 30 is stopped in step S34, and the cold storage amount control processing is completed. That is, the stop of the compressor 30 is based on the determination that the vehicle 100 is in operation in step S10, the determination that cold storage cooling is performed in step S12, and the determination that the compressor 30 is stopped in step S16. Will be implemented. The compressor 30 is stopped until the cold storage amount Qc reaches the lower limit threshold value Qs1, and this lower limit threshold value Qs1 is set by the probability of occurrence of the engine stop of the vehicle 100. Therefore, it can be said that the compressor 30 is stopped based on this probability of occurrence. In this embodiment, the process of step S34 corresponds to the "control unit".

On the other hand, if a negative determination is made in step S14, it is determined in step S40 whether the cold storage amount Qc is equal to or less than the lower limit threshold value Qs1. If affirmative determination is made in step S40, the compressor 30 is driven in step S44 to end the cold storage amount control process.

On the other hand, if a negative determination is made in step S40, it is determined in step S42 whether to drive the compressor 30 based on the energy efficiency. When the engine efficiency is lowered by driving the compressor 30, a negative determination is made in step S40, and the cold storage amount control process is terminated. On the other hand, when the engine efficiency is improved by driving the compressor 30, a positive determination is made in step S42, and the process proceeds to step S44. In the present embodiment, the processing of steps S16 and S42 corresponds to the "stop determination unit", and the determination result of steps S16 and S42 corresponds to the "determination result".

On the other hand, if a negative determination is made in step S10, in step S50, the correction process is performed in the specified period after the ignition switch of the vehicle 100 is switched from on to off, and the cold storage amount control process is terminated. During the specified period, as a so-called main relay control, the power supply to the ECU 40 is continued for a certain period of time even after the ignition switch is turned off. Here, the correction process is a process of correcting the decrease change amount Qg associated with the day of the week information Iw and the time zone information It in the corresponding map MP.

FIG. 3 shows a flowchart of the correction process of the present embodiment. When the correction process is started, first, in step S60, it is determined whether the correction condition is satisfied. For example, it is determined whether the mileage in the driving cycle (hereinafter referred to as the target cycle) completed immediately before the correction process is longer than the specified distance.

If a negative determination is made in step S60, the correction process ends. On the other hand, if an affirmative determination is made in step S60, the fuel consumption Ef of the vehicle 100 in the target cycle is calculated in the following step S62. The fuel consumption Ef can be calculated from the fuel injection amount and the mileage of the fuel injection valve 11 in the target cycle. In this embodiment, the process of step S62 corresponds to the "fuel consumption calculation unit".

In step S64, the return probability Cb of the compressor 30 in the target cycle is calculated. Here, the return probability Cb is a probability that the engine 10 is restarted due to a shortage of the cold storage amount Qc while the engine of the vehicle 100 is stopped, and the drive of the compressor 30 is restored. The return probability Cb indicates the ratio of the number of times Nb that the drive of the compressor 30 is restored within the engine stop period Ys. The return probability Cb is expressed as (Equation 2).

Cb = Nb / Ys × 100 ... (Equation 2)
In step S66, it is determined whether to correct the decrease change amount Qg based on the fuel consumption Ef calculated in step S62. Specifically, it is determined whether the fuel consumption Ef calculated in step S62 is larger than the reference fuel consumption Ek. Here, the reference fuel consumption Ek is a driving cycle in which the day of the week information Iw and the time zone information It are equal to the target cycle, and the fuel consumption Ef calculated in the driving cycle (hereinafter referred to as the previous cycle) carried out immediately before the target cycle. Is shown.

If affirmative determination is made in step S64, it is determined that the fuel efficiency Ef of the vehicle 100 has improved. In this case, the reference fuel consumption Ek is updated using the fuel consumption Ef calculated in step S62 in the subsequent step S72 without correcting the decrease change amount Qg, and the correction process is terminated.

On the other hand, if a negative determination is made in step S66, it is determined that the fuel efficiency Ef of the vehicle 100 has deteriorated. In this case, in step S68, it is determined whether the return probability Cb calculated in step S64 is smaller than the reference probability Ck. Here, the reference probability Ck indicates the return probability Cb calculated in the previous cycle.

If affirmative determination is made in step S68, it is determined that the return probability Cb of the compressor 30 has improved. In this case, the process proceeds to step S72 without correcting the decrease change amount Qg.

On the other hand, if a negative determination is made in step S68, it is determined that the return probability Cb of the compressor 30 has deteriorated. In this case, in step S70, the reduction change amount Qg is reduced and corrected, and the correction process is terminated. In this embodiment, the process of step S70 corresponds to the "correction unit".

Subsequently, FIG. 6 shows an example of the cold storage amount control process. FIG. 6A shows the transition of the fuel cut state F / C in the normal control, and FIG. 6B shows the transition of the fuel cut state F / C in the reduction control. In FIG. 6, (a) shows the transition of the cold storage amount Qc, (b) shows the transition of the driving state of the compressor 30, (c) shows the transition of the fuel cut state F / C, and (d) shows the transition. The energy loss El generated by switching the fuel cut state F / C is shown.

Further, FIG. 7 shows the negative torque Tn during the engine operation of the vehicle 100. FIG. 7A shows the negative torque Tn when the fuel cut state is not performed, that is, the fuel cut state F / C is off, and FIG. 7B shows the fuel cut state, that is, the fuel cut state F / C. The negative torque Tn when C is on is shown. In FIG. 7, the negative torque Tn is described as an amount that increases to the negative side because it acts in the direction opposite to the rotation direction of the crank shaft 13 of the engine 10.

As shown in FIG. 6A, when the cold storage amount Qc rises to the upper limit threshold value Qs2 at time t1, the compressor 30 is switched to the off state while the engine of the vehicle 100 is operating. In the present embodiment, the upper limit threshold value Qs2 is set to 100%, but the upper limit threshold value Qs2 does not necessarily have to be set to 100%.

As shown in FIG. 7A, when the compressor 30 is maintained in the ON state while the engine of the vehicle 100 is operating, a drive torque Tc is generated. As a result, when the negative torque Tn becomes large and the deceleration of the vehicle 100 becomes excessively large, the driver depresses the accelerator pedal in order to accelerate the vehicle 100, and the engine rotation speed Ne is increased. That is, the excess of the negative torque Tn is supplemented by the accelerator torque Ta by depressing the accelerator pedal. As a result, the fuel cut state F / C cannot be turned on while the engine of the vehicle 100 is operating, and the fuel consumption Ef of the vehicle 100 during the engine operation of the vehicle 100 deteriorates.

In the present embodiment, the compressor 30 is switched to the off state while the engine of the vehicle 100 is operating. As a result, as shown in FIG. 7B, the negative torque Tn is reduced. As a result, the driver is suppressed from depressing the accelerator pedal while the engine of the vehicle 100 is operating, and the increase in the engine rotation speed Ne is suppressed, so that the engine efficiency is improved. Further, when the fuel cut state F / C is turned on during the engine operation of the vehicle 100 (see FIG. 6C), the fuel injection amount during the engine operation of the vehicle 100 is reduced. In the present embodiment, the fuel efficiency Ef of the vehicle 100 while the engine of the vehicle 100 is operating can be improved by improving the engine efficiency and reducing the fuel injection amount.

FIG. 8 shows a characteristic map ME of engine efficiency characteristics. In the characteristic map ME, the torque curve of the engine 10 is determined with the engine rotation speed Ne and the negative torque Tn as parameters, and the magnitude of the engine efficiency in each region is determined. Is indicated by contour lines. The engine efficiency characteristic is also a characteristic representing an equal fuel consumption curve. Of these, the high-efficiency region Fh is defined as the region including the highest efficiency point, and the relationship is defined in which the engine efficiency decreases as the distance from the high-efficiency region Fh increases.

For example, when the current operating state of the engine 10 is the state Fa on the high rotation speed side of the high efficiency region Fh, the operating state of the engine 10 can be changed to the high efficiency region Fh by switching the compressor 30 to the off state. It becomes possible to operate the engine 10 within the high efficiency region Fh. As a result, the engine 10 can be operated with high efficiency (low fuel consumption), and the fuel injection amount during the engine operation of the vehicle 100 is reduced. As a result, it is possible to improve the fuel efficiency Ef of the vehicle 100 while the engine of the vehicle 100 is operating.

As shown in FIG. 6A, specifically, the compressor 30 can be switched to the off state during the period when the cold storage amount Qc decreases from the upper limit threshold value Qs2 to the lower limit threshold value Qs1, and the engine of the vehicle 100 is operating. It is possible to improve the fuel consumption Ef of the vehicle 100 in the above. That is, it can be said that the range in which the cold storage amount Qc is from the upper limit threshold value Qs2 to the lower limit threshold value Qs1 is the compression stop range Hg in which the compressor 30 can be stopped.

In normal control, the compression stop range Hg is set narrow in order to continue stopping the compressor 30 while the engine of the vehicle 100 is stopped. For example, when the cold storage amount Qc drops to a cold storage threshold Qs3 smaller than the lower limit threshold Qs1 while the engine is stopped, the ECU 40 restores the drive of the compressor 30 to store the cold storage amount Qc. In order to prolong the period until the drive of the compressor 30 is restored while the engine is stopped, it is necessary to widen the range Hs from the cold storage threshold value Qs3 to the lower limit threshold value Qs1. As a result, the lower limit threshold value Qs1 is set to a relatively large value, and the compression stop range Hg is set narrow.

Therefore, in normal control, the fuel cut period Yf at which the fuel cut state F / C is turned on is reduced. As shown in FIG. 6A, in the normal control, the cold storage amount Qc starts to decrease from the upper limit threshold value Qs2 at time t1, and the cold storage amount Qc decreases to the lower limit threshold value Qs1 at time t2. The fuel cut period Yf from time t1 to time t2 is reduced according to the narrowly set compression stop range Hg. As a result, the effect of improving the fuel efficiency of the vehicle 100 by the fuel cut state F / C is reduced.

In the present embodiment, the reduction control is performed on condition that it is determined that the probability of occurrence of engine stop during the operation of the vehicle 100 is low. Specifically, as shown in FIG. 6B, the lower limit threshold value Qs1 is reduced by the reduction change amount Qg. As a result, the compression stop range Hg is expanded, and the fuel cut period Yf is extended to the time t3 after the time t2. As a result, the effect of improving the fuel efficiency of the vehicle 100 by the fuel cut state F / C is increased, and the fuel efficiency Ef of the vehicle 100 while the engine of the vehicle 100 is operating can be improved.

The period Yr required for the cold storage amount Qc to rise to the upper limit threshold Qs2 after the cold storage amount Qc drops to the lower limit threshold value Qs1 is shorter when the compression stop range Hg is narrower than when it is wide. Therefore, as shown in FIG. 6, when the low probability period in which the engine stop occurrence probability is determined to be low is relatively long during the operation of the vehicle 100 and the fuel cut period Yf is repeated a plurality of times, the compression stop range When Hg is narrow, the fuel cut period Yf per one time is short, but the number of repetitions is large. Further, when the compression stop range Hg is wide, the fuel cut period Yf per one time is long, but the number of repetitions is small. As a result, it is considered that the ratio of the total period of the fuel cut period Yf to the low probability period of the vehicle 100 is constant regardless of the compression stop range Hg.

However, as shown in FIG. 6, when the fuel cut state F / C is switched from on to off, and when the fuel cut state F / C is switched from off to on, energy is generated by, for example, overshoot of the compressor 30. Loss El occurs. When the compression stop range Hg is wide, the number of times the fuel cut state F / C is switched is small, and the number of times the energy loss El is generated is small. Therefore, even when the low probability period of the vehicle 100 is relatively long, the fuel consumption Ef of the vehicle 100 during the engine operation of the vehicle 100 can be improved by reducing the lower limit threshold value Qs1 by the reduction change amount Qg.

According to the present embodiment described in detail above, the following effects can be obtained.

-While the engine is operating, the fuel consumption Ef of the vehicle 100 can be improved by performing the cold storage cooling to cut the fuel and stopping the compressor 30. However, if the cold storage amount Qc drops to the lower limit threshold value Qs1 during engine operation, the cold storage amount Qc drops to the cold storage threshold Qs3 while the engine of the vehicle 100 is stopped, and the compressor 30 cannot be continuously stopped.

-In the present embodiment, the probability of occurrence of engine stop indicated by the average speed Vav and the low-speed period ratio Pt is acquired during the operation of the vehicle 100, and the probability of occurrence of the engine stop is obtained during the cold storage cooling, and the vehicle 100 is based on this probability of occurrence. The compressor 30 is stopped while the engine is operating. In this case, when the probability of occurrence of engine stop is low, the fuel efficiency Ef of the vehicle 100 during engine operation can be improved by enabling cold storage and cooling with the compressor 30 stopped during engine operation. Can be done. Further, when the probability of occurrence of engine stop is high, the compressor 30 can be maintained in the stopped state while the engine is stopped by not stopping the compressor 30 while the engine is operating. As a result, it is possible to improve the fuel efficiency Ef of the vehicle 100 while the engine is stopped and the engine is operating.

-In particular, in the present embodiment, when the compressor 30 is stopped during engine operation, it is determined whether to stop the compressor 30 based on the engine efficiency with respect to the high efficiency region Fh. As a result, the engine efficiency can be improved by stopping the compressor 30, and the fuel efficiency Ef of the vehicle 100 during the engine operation can be improved by increasing the engine efficiency.

-In the present embodiment, when the probability of occurrence of engine stop is lower than the predetermined probability indicated by the reference speed Vk or the reference ratio Pk, the lower limit threshold value Qs1 is changed to a smaller side. As a result, the stop period of the compressor 30 during the engine operation of the vehicle 100, that is, the fuel cut period Yf can be lengthened, and the fuel consumption Ef of the vehicle 100 can be improved.

-In the present embodiment, the lower the probability of engine stop occurring, the larger the reduction change amount Qg to be changed to the side where the lower limit threshold value Qs1 is reduced. When the probability of occurrence of engine stop is low, it is not necessary to leave an excessive amount of cold storage Qc for cold storage and cooling while the engine is stopped. Therefore, the lower the probability of engine stop occurring, the larger the reduction change amount Qg can be set, so that the reduction change amount Qg can be suitably set according to the traveling state of the vehicle 100. As a result, the compressor 30 can be continuously stopped while the engine is operating, and the fuel consumption Ef of the vehicle 100 can be improved.

-In the present embodiment, the corresponding map MP in which the decrease change amount Qg is predetermined is stored corresponding to the day of the week information Iw and the time zone information It, and the day of the week information Iw, the time zone information It, and the corresponding map MP are stored. The reduction change amount Qg is set based on. For example, the frequency of traffic congestion differs between weekdays and holidays, and between commuting hours and other hours. That is, the probability of occurrence of engine stop varies depending on the day of the week information Iw and the time zone information It. Therefore, by setting the reduction change amount Qg based on the day of the week information Iw and the time zone information It, it is possible to suppress the variation due to the day of the week information Iw and the time zone information It and preferably set the reduction change amount Qg. ..

-In the present embodiment, the fuel consumption Ef of the vehicle 100 is calculated for each driving cycle, and the reduction change amount Qg specified in the corresponding map MP is corrected based on the calculated fuel consumption Ef. Thereby, the decrease change amount Qg can be appropriately corrected so that the fuel consumption Ef of the vehicle 100 is improved.

-If the lower limit threshold value Qs1 is reduced and changed, the cold storage amount Qc at the start of engine stop of the vehicle 100 may be excessively lowered. Therefore, the compressor 30 cannot be continuously stopped while the engine is stopped, and the engine 10 must be started in order to start the compressor 30. As a result, the fuel consumption Ef of the vehicle 100 deteriorates. In the present embodiment, the lower limit threshold value Qs1 is reduced and changed on condition that the change permission mode is selected. Therefore, when the change prohibition mode is selected, the lower limit threshold value Qs1 can be prevented from being reduced or changed. As a result, the compressor 30 can be continuously stopped while the engine of the vehicle 100 is stopped, and the deterioration of the fuel efficiency Ef of the vehicle 100 can be suppressed.

-In the present embodiment, the probability of occurrence of engine stop is determined based on the average speed Vav. When the average speed Vav is large, it is expected that the probability of engine stop occurring is lower than when the average speed Vav is small. In this way, the average speed Vav and the probability of occurrence of engine stop correlate. Therefore, the probability of occurrence of engine stop can be suitably determined based on the average speed Vav.

-In the present embodiment, the probability of occurrence of engine stop is determined based on the forward course information If. For example, when information on the occurrence of traffic congestion in the forward course of the vehicle 100 is acquired as the forward course information If, it is expected that the probability of engine stop occurring will increase. In this way, the forward course information If and the probability of engine stop occurring correlate with each other. Therefore, it is possible to suitably determine the probability of occurrence of engine stop based on the forward course information If.

-In the present embodiment, the probability of occurrence of engine stop is determined based on the low speed period ratio Pt. When the low speed period ratio Pt is large, it is expected that the probability of engine stop occurring is lower than when it is small. In this way, the low-speed period ratio Pt and the probability of engine stop occurring correlate. Therefore, the probability of occurrence of engine stop can be suitably determined based on the low speed period ratio Pt.

The present invention is not limited to the description of the above embodiment, and may be implemented as follows.

-In the embodiment, an example is shown in which the probability of occurrence of engine stop during operation of the vehicle 100 is determined based on the average speed Vav and the low speed period ratio Pt, but the present invention is not limited to this. For example, it may be determined that the operation of the engine 10 is repeatedly stopped and restarted.

-In the embodiment, when it is determined that the probability of occurrence of engine stop during the operation of the vehicle 100 is low, only the reduction change of the lower limit threshold value Qs1 is performed, but the present invention is not limited to this. For example, in normal control, when the upper limit threshold value Qs2 is set to a value lower than 100%, when it is determined that the probability of occurrence of engine stop is low, the lower limit threshold value Qs1 is reduced and the upper limit threshold value Qs2 is set. Increase changes may be implemented on the larger side.

-In the embodiment, an example is shown in which the engine efficiency characteristic has the engine rotation speed Ne and the negative torque Tn as parameters, but the present invention is not limited to this. For example, an engine load such as an intake air amount to the engine 10 or an intake negative pressure may be used as a parameter.

-In the embodiment, information on the occurrence of traffic congestion in the forward course of the vehicle 100 is exemplified as the forward course information If, but the present invention is not limited to this, and is, for example, information on a destination or a planned driving route in the current driving cycle. May be good.

-The time zone information It is not limited to that shown in FIG.

-In the embodiment, an example in which the reference fuel consumption Ek is the fuel consumption Ef calculated in the previous cycle is shown, but the present invention is not limited to this. For example, among a plurality of fuel consumption Ef corresponding to a plurality of driving cycles having the same day information Iw and time zone information It, the maximum fuel consumption Ef may be set as the reference fuel consumption Ek.

-In the embodiment, an example in which the reduction correction is performed as the correction of the reduction change amount Qg is shown, but the present invention is not limited to this. Depending on the calculated fuel consumption Ef and the return probability Cb, the decrease change amount Qg may be increased and corrected.

-In the embodiment, as shown in FIG. 6B, an example is shown in which the compressor 30 is maintained in the off state until the cold storage amount Qc that has started to decrease reaches the lower limit threshold value Qs1, but this is limited to this. I can't. As shown in FIG. 9, the compressor 30 may be switched to the ON state at an arbitrary timing until the cold storage amount Qc drops to the lower limit threshold value Qs1.

-Similarly, as shown in FIG. 6B, an example is shown in which the compressor 30 is maintained in the ON state until the cold storage amount Qc that has started to rise reaches the upper limit threshold value Qs2, but this is limited to this. not. As shown in FIG. 9, the compressor 30 may be switched to the off state at an arbitrary timing until the cold storage amount Qc rises to the upper limit threshold value Qs2.

-And, in the present embodiment, the lower limit threshold value Qs1 is reduced and changed in the reduction control. Therefore, it is possible to increase the degree of freedom in the switching timing for switching the compressor 30 from the off state to the on state. Specifically, as shown in FIG. 9, in the normal control, when the cold storage amount Qc reaches the normal threshold value Qse, which is the lower limit threshold value Qs1 in the normal control, it is necessary to switch the compressor 30 to the on state. In the present embodiment, even if the cold storage amount Qc reaches the normal threshold value Qse, it is not necessary to switch the compressor 30 to the on state, and the degree of freedom in the switching timing for switching the compressor 30 from the off state to the on state is increased. Can be done. The same applies to the switching timing for switching the compressor 30 from the on state to the off state.

-In the embodiment, the cold storage 36 is provided in the evaporator 34, but the arrangement of the cold storage 36 is not limited to this, and for example, the cold storage 36 is provided between the refrigerant suction port of the compressor 30 and the evaporator 34. If it may be connected, the evaporator 34 and the cooler 36 may be connected in parallel.

13 ... crank shaft, 30 ... compressor, 36 ... cold storage, 39 ... refrigeration cycle, 100 ... vehicle.

Claims (10)

It is applied to a vehicle (100) equipped with a refrigeration cycle (39) including a compressor (30) driven by rotation of an engine output shaft (13) and a cold storage (36) provided in a refrigerant path.
Occurrence probability acquisition units (S18, S22) that acquire the occurrence probability of engine stop during operation of the vehicle, and
A control device including a control unit (S34) for stopping the compressor while the engine of the vehicle is operating, based on the probability of occurrence when the vehicle interior is cooled by the refrigeration cycle. A stop determination unit (S16, S42) for determining whether to drive or stop the compressor based on the engine efficiency for a predetermined high efficiency region (Fh) including the highest efficiency point is provided.
The control device according to claim 1, wherein the control unit stops the compressor while the engine of the vehicle is operating, based on the occurrence probability and the determination result by the stop determination unit. The control unit stops the compressor while the engine of the vehicle is operating while the cold storage amount (Qc) of the cold storage device drops from the upper limit threshold value (Qs2) to the lower limit threshold value (Qs1).
The control device according to claim 1 or 2, further comprising a change unit (S32) for changing the lower limit threshold value to the side where the occurrence probability is lower than the predetermined probability. The control device according to claim 3, wherein the change unit sets a larger change amount (Qg) to the side where the lower limit threshold value is made smaller as the probability of occurrence of the engine stop is lower. The time information acquisition unit (S26) for acquiring the day of the week information (Iw) and the time zone information (It),
A storage unit (42) for storing correspondence information (MP) in which the day of the week information, the time zone information, and the change amount are associated with each other is provided.
The control device according to claim 4, wherein the change unit sets the change amount based on the acquired day of the week information, the time zone information, and the corresponding information. A fuel consumption calculation unit (S62) that calculates the fuel consumption (Ef) of the vehicle for each driving cycle of the vehicle,
The control device according to claim 4 or 5, further comprising a correction unit (S70) for correcting the change amount based on the fuel consumption of the vehicle. A selection unit (S30) for selecting one of a change permission mode for permitting the change of the lower limit threshold value and a change prohibition mode for prohibiting the change of the lower limit threshold value is provided.
The control device according to any one of claims 3 to 6, wherein the change unit is changed to a side that reduces the lower limit threshold value on condition that the change permission mode is selected. The control device according to any one of claims 1 to 7, wherein the occurrence probability acquisition unit acquires the occurrence probability of the engine stop based on the vehicle speed (Vm). It is equipped with a traffic information acquisition unit (S20) that acquires forward course information (If) as information indicating the traffic status of the vehicle forward course.
The control device according to any one of claims 1 to 8, wherein the occurrence probability acquisition unit acquires the occurrence probability of the engine stop based on the forward course information. The first to ninth aspects of the engine stop acquisition unit acquire the probability of occurrence of the engine stop based on the ratio (Pt) of the period during which the speed of the vehicle becomes slower than the reference speed within a predetermined period. The control device according to any one.

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