JP2018119445A - Engine stop / start control device - Google Patents

Abstract

To provide an engine stop / start control device capable of suppressing a decrease in merchantability of a vehicle while ensuring improvement in fuel consumption. An engine stop / start control device that controls a function of stopping an engine mounted on a vehicle when a stop condition is satisfied and restarting the engine when the restart condition is satisfied is resumed from the stop of the engine due to the satisfaction of the stop condition. The acquisition unit that acquires the automatic stop time, which is the time until the engine restarts when the start condition is satisfied, and the engine stop when the stop condition is satisfied when the automatic stop time acquired by the acquisition unit is within a predetermined time And a control unit for prohibiting. [Selection] Figure 3

Description

  The present invention relates to an engine stop / start control device that controls a function of stopping an engine mounted on a vehicle when a stop condition is satisfied and restarting the engine when the restart condition is satisfied.

  Patent Document 1 describes an automatic stop / start device for a vehicle that can prevent the battery from running off due to the automatic stop / start of the engine. This automatic stop start device operates the engine by prohibiting the automatic stop of the engine until the state of charge of the battery reaches a state of charge necessary for starting the engine even when a predetermined stop condition is satisfied after the engine is started. Let In other words, even if the stop condition is satisfied after the engine is started, the engine is not automatically stopped as in the conventional case, but the automatic stop of the engine is temporarily prohibited, and the state of charge of the battery becomes the state of charge necessary for starting the engine. Run the engine until

JP-A-8-61109

  The automatic stop / start device described in Patent Document 1 described above stops the operation of the engine when the state of charge of the battery reaches a state of charge necessary for starting the engine. Thereafter, the state of charge of the battery due to an excessive load is detected. If the charge state of the battery drops to a state that does not reach the charge state necessary for starting the engine due to a decrease or a detection error of a sensor that detects the charge state of the battery, the engine is started again. In this way, if the engine stop and start are repeated while the so-called idle stop condition is satisfied, the quietness is reduced due to vibrations etc. accompanying the stop and start of the engine, and the merchantability of the vehicle is reduced. To do. On the other hand, from the viewpoint of improving fuel efficiency, idling stop is a required function.

  An object of the present invention is to provide an engine stop / start control device capable of suppressing a decrease in the merchantability of a vehicle while ensuring an improvement in fuel consumption.

In order to achieve the above object, the invention described in claim 1
An engine stop / start control device (for example, described later) that controls a function of stopping an engine (for example, an engine 101 in an embodiment described later) mounted on the vehicle when the stop condition is satisfied and restarting when the restart condition is satisfied. ECU 113) in the embodiment of
An acquisition unit that acquires an automatic stop time, which is a time from the stop of the engine due to the establishment of the stop condition to the restart of the engine due to the establishment of the restart condition (for example, automatic stop time measurement in an embodiment described later) Part 155),
When the automatic stop time acquired by the acquisition unit is within a predetermined time, a control unit that prohibits the engine from being stopped when the stop condition is satisfied (for example, an I / S control unit 157 in an embodiment described later) When,
An engine stop / start control device.

The invention according to claim 2 is the invention according to claim 1,
The restart condition is a condition based on a state of a battery (for example, a battery 107 in an embodiment described later) mounted on the vehicle or a parameter related to the battery.

The invention according to claim 3 is the invention according to claim 1 or 2,
The control unit prohibits the engine from being stopped when the stop condition is satisfied when the acquisition unit acquires the automatic stop time within the predetermined time a plurality of times.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
The control unit continues prohibition control for prohibiting the stop of the engine due to the establishment of the stop condition until the vehicle enters a resting state, and releases the prohibition control when the vehicle is started again.

  In the invention of claim 1, after the stop condition is satisfied and the engine is stopped, an event occurs in which the engine is stopped and restarted in succession, for example, the restart condition is satisfied and the engine is restarted within a predetermined time. In such a case, prohibition control is performed to prohibit the engine from being stopped even if the stop condition is satisfied so that the same event does not occur. For this reason, it is possible to suppress the occurrence of the same event after the occurrence of the above event, and it is possible to suppress a decrease in quietness due to vibration or the like that occurs when the engine is stopped and started. On the other hand, until the prohibition control is performed, fuel consumption can be improved by a so-called idle stop function that stops when the stop condition is satisfied and restarts when the restart condition is satisfied. Therefore, it is possible to suppress a decrease in the merchantability of the vehicle while ensuring an improvement in fuel consumption.

  In the invention of claim 2, even if the engine is stopped due to the establishment of the stop condition, if the condition based on the battery state or the parameter relating to the battery is satisfied and the engine is restarted within a predetermined time, the engine is thereafter Prohibit stop control. Since the restart condition is based on the state of the battery or the parameters related to the battery, the event that the restart is performed immediately after the engine is stopped is caused by the deterioration of the battery due to the deterioration or exhaustion of the battery or the failure of the sensor that detects the parameters related to the battery. Possible cause. Since the engine starts using the torque of an electric motor driven by electric power from the battery, when the engine is stopped, there is a possibility that sufficient electric power is not supplied from the battery and cannot be restarted. However, a situation in which the engine cannot be restarted can be prevented by performing the engine stop prohibition control and not stopping the engine as in the present invention. Further, by performing the engine stop prohibition control, vibrations or the like due to engine stop and start are not generated, so that the merchantability of the vehicle can be maintained.

  According to the third aspect of the present invention, the engine stop prohibition control is performed when an event that continuously stops and restarts the engine occurs a plurality of times. If the engine stop prohibition control is performed, fuel efficiency is not expected to be improved. Therefore, it is better not to perform the prohibition control as long as the merchantability can be maintained. In the present invention, since the prohibition control is performed after a plurality of events, the execution of the prohibition control can be determined more carefully than the determination of whether to perform the prohibition control based on the occurrence of a single event.

  According to the invention of claim 4, the engine stop prohibition control set during the period from start to stop of the vehicle, that is, during a certain driving cycle, is not taken over in the next driving cycle. Since the battery state detection and sensor learning are performed again when the vehicle is started, the event that the engine is stopped and restarted during the previous driving cycle may not occur in the next driving cycle. is there. For this reason, it is possible to appropriately determine whether or not the engine stop prohibition control is necessary by not taking over the prohibition control across the driving cycle.

It is a block diagram which shows the internal structure of the vehicle provided with the engine stop start control apparatus of one Embodiment. It is a block diagram which shows the internal structure of ECU which controls an idle stop function. FIG. 10 is a timing chart in a case where idle stop prohibition control is performed by three short idle stops with an automatic stop time of less than 5 seconds. It is a flowchart which shows the flow of the process which an I / S control part performs.

  Hereinafter, an embodiment of a vehicle provided with an engine stop / start control device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an internal configuration of a vehicle including an engine stop / start control device according to an embodiment. 1 includes an engine (ENG) 101, a starter motor (hereinafter simply referred to as “starter”) 103, a transmission (T / M) 105, a battery (BAT) 107, a vehicle speed sensor 109, A battery sensor 111 and an ECU 113 are provided. In the vehicle, the power output from the engine 101 is transmitted to the drive wheels DW and DW via the transmission 105, the differential gear 8 and the left and right axles 9 and 9. In FIG. 1, a thick solid line indicates mechanical connection, a double dotted line indicates power wiring, and a thin solid line arrow indicates a control signal or a detection signal.

  Hereafter, each component which the vehicle of FIG. 1 has is demonstrated.

  The engine 101 outputs power for running the vehicle. The rotation shaft of the engine 101 is connected to the input shaft of the transmission 105 and the rotor of the starter 103.

  The starter 103 is an electric motor that starts the engine 101.

  The transmission 105 shifts the power from at least one of the engine 101 and the starter 103 at a predetermined gear ratio and transmits it to the drive wheels DW. The transmission ratio of the transmission 105 is changed according to an instruction from the ECU 113. The transmission 105 includes a clutch CL that connects and disconnects a power transmission path between the engine 101 and the drive wheels W and W.

  The battery 107 has a plurality of power storage cells connected in series or in parallel. The battery 107 is, for example, a lead storage battery.

  The vehicle speed sensor 109 detects the traveling speed (vehicle speed VP) of the vehicle. A signal indicating the vehicle speed VP detected by the vehicle speed sensor 109 is sent to the ECU 113.

  The battery sensor 111 detects the output (terminal voltage, charge / discharge current) of the battery 107 and detects SOC (State Of Charge) indicating the charge state of the battery 107. A signal indicating the SOC, terminal voltage, integrated charge / discharge current value, etc. detected by the battery sensor 111 is sent to the ECU 113.

  The ECU 113 performs operation control of the engine 101, drive control of the starter 103, shift control in the transmission 105, and the like. Further, the ECU 113 controls a function (idle stop function) for stopping the idling operation of the engine 101 during parking or stopping for a signal or the like for the purpose of improving the fuel efficiency in traveling of the vehicle. FIG. 2 is a block diagram showing an internal configuration of the ECU 113 that controls the idle stop function. As shown in FIG. 2, the ECU 113 includes a stop condition establishment determination unit 151, a restart condition establishment determination unit 153, an automatic stop time measurement unit 155, and an I / S control unit 157. Hereinafter, each component which ECU113 has is demonstrated.

  The stop condition establishment determination unit 151 performs an idle stop based on the state of the vehicle including the accelerator pedal opening (AP opening) according to the accelerator pedal operation by the vehicle driver and the vehicle speed VP obtained from the vehicle speed sensor 109. It is determined whether a condition for execution, that is, a condition for stopping the engine 101 (stop condition) is satisfied. When the stop condition is satisfied, the stop condition satisfaction determining unit 151 performs a process for stopping the engine 101 according to a condition set by an I / S control unit 157 described later.

  Based on the AP opening and the state of the vehicle including the battery information obtained from the battery sensor 111, the restart condition establishment determining unit 153 determines a condition for releasing the idle stop, that is, a condition for restarting the engine 101 (re-starting). It is determined whether (starting condition) is satisfied. The restart condition establishment determining unit 153 performs a process for starting the engine 101 when the restart condition is established.

  The automatic stop time measuring unit 155 is the time from the time ts when the stop condition is satisfied and the engine 101 is stopped for each idle stop to the time tr when the restart condition is satisfied and the engine 101 is restarted (hereinafter referred to as “automatic stop”). It is referred to as “time”.) Td (= tr−ts) is measured.

  As shown in FIG. 3, the I / S control unit 157 performs control for prohibiting the subsequent idle stops when three short idle stops (I / S) with an automatic stop time td of less than 5 seconds occur. When the idle stop prohibition control is performed by the I / S control unit 157, the stop condition satisfaction determining unit 151 does not perform processing for stopping the engine 101 even if the stop condition is satisfied. The I / S control unit 157 continues the prohibition control until the ignition switch (IGSW) is turned off and the vehicle is in a resting state, and is released when the ignition switch is turned on again and the vehicle is activated.

  FIG. 4 is a flowchart showing a flow of processing performed by the I / S control unit 157. As shown in FIG. 4, the I / S control unit 157 determines whether or not the ignition switch (IGSW) is turned on and the vehicle is activated (step S101). If the vehicle is activated, the process proceeds to step S103. In step S103, the I / S control unit 157 initializes the number N of idle stop occurrences of less than 5 seconds to 0, and cancels the idle stop prohibition control set during the previous driving cycle.

  Next, the I / S control unit 157 acquires the automatic stop time td measured by the automatic stop time measuring unit 155 (step S105). Next, the I / S control unit 157 determines whether or not the automatic stop time td acquired in step S105 is less than 5 seconds (td <5 seconds) (step S107), and if td <5 seconds. Proceeding to step S109, if td ≧ 5 seconds, the process returns to step S105. In step S109, the I / S control unit 157 increments the number N of occurrences. Next, the I / S control unit 157 determines whether or not the number of occurrences N has reached 3 (step S111). If the number of occurrences N = 3, the process proceeds to step S113, where the number of occurrences N is less than 3. If there is, the process returns to step S105.

  In step S113, the I / S control unit 157 performs idle stop prohibition control so that the stop condition satisfaction determination unit 151 does not perform the engine stop process even if the stop condition is satisfied. The I / S control unit 157 continues the prohibition control set in step S113 until the ignition switch is turned off and the vehicle enters a dormant state.

  Note that the idle stop automatic stop time td used as the number of occurrences N used in step S107 is not limited to less than 5 seconds. The automatic stop time td is set to a time interval in which a vehicle occupant tends to feel uncomfortable when vibration or the like frequently occurs due to repeated stop and restart of the engine 101.

  Further, the number of occurrences N for starting the idle stop prohibition control used in step S111 is not limited to three. However, in the present embodiment, it is considered that the idling stop having a short automatic stop time td occurs three times in a scene where the vehicle travels normally. For example, even when driving on a heavily congested road in the center of a city, the number of idle stops in less than 5 seconds occurs at most twice. For this reason, in the present embodiment, the number of occurrences N for starting the idle stop prohibition control used in step S111 is set to three.

  As described above, in the present embodiment, when a short idle stop having an automatic stop time td of less than 5 seconds occurs three times, the subsequent idle stop is prohibited. For this reason, after the prohibition control, vibration associated with stop and start of the engine 101 due to idle stop does not occur. As a result, it is possible to improve the fuel consumption by the idle stop until the prohibition control is performed, and after the prohibition control, it is possible to suppress a decrease in quietness due to the vibration of the idle stop. Therefore, it is possible to suppress a decrease in the merchantability of the vehicle while ensuring an improvement in fuel consumption.

  Further, in the present embodiment, although the prohibition control can be executed, a situation in which a short idle stop such as less than 5 seconds occurs three times hardly occurs in normal traveling. For this reason, this situation is considered to be an event that occurs because the restart condition is satisfied even when the idle stop is started due to deterioration of the state due to deterioration or exhaustion of the battery, failure of the battery sensor 111, or the like. Since the engine is started using the torque of the starter 103 driven by the electric power from the battery 107, if the engine 101 is stopped by idling stop, sufficient power is not supplied from the battery 107 in such a state, and the engine 101 is restarted. It may not be possible to start. However, the situation where the engine 101 cannot be restarted can be prevented by performing the idle stop prohibition control and not stopping the engine 101 as in the present embodiment.

  Further, the idle stop prohibition control set during a certain driving cycle is not carried over to the next driving cycle. Since the detection of the state of the battery 107 and the learning of the battery sensor 111 are performed again at the time of starting the vehicle, the event that frequently occurs during the previous driving cycle that the short idle stop frequently occurs may not occur in the next driving cycle. . For this reason, the necessity of the prohibition control can be appropriately determined by not taking over the prohibition control of the idle stop across the driving cycle.

  Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like can be made as appropriate. For example, an ISG (Integrated Starter Generator) is provided in the vehicle, in place of the starter 103, in addition to starting the engine 101, generating auxiliary torque that assists the output of the engine 101, or performing a regenerative operation by at least part of the output of the engine 101. May be installed. In this case, since ISG uses relatively large electric power, the battery 107 is a battery capable of supplying a high voltage of, for example, 100 to 200 V, in which power storage cells such as lithium ion batteries and nickel metal hydride batteries are connected in series. Used.

101 engine (ENG)
103 Starter motor (SMOT)
105 Transmission (T / M)
107 Battery (BAT)
109 Vehicle speed sensor 111 Battery sensor 113 ECU
151 Stop condition establishment determination unit 153 Restart condition establishment determination unit 155 Automatic stop time measurement unit 157 I / S control unit

Claims (4)

An engine stop / start control device for controlling a function of stopping an engine mounted on a vehicle when a stop condition is satisfied and restarting when the restart condition is satisfied,
An acquisition unit for acquiring an automatic stop time, which is a time from the stop of the engine due to establishment of the stop condition to the restart of the engine due to establishment of the restart condition;
When the automatic stop time acquired by the acquisition unit is within a predetermined time, a control unit prohibiting the stop of the engine due to establishment of the stop condition;
An engine stop / start control device. The engine stop / start control device according to claim 1,
The engine stop start control device, wherein the restart condition is a condition based on a state of a battery mounted on the vehicle or a parameter related to the battery. The engine stop / start control device according to claim 1 or 2,
The said control part is an engine stop start control apparatus which prohibits the stop of the said engine by establishment of the said stop condition, when the said acquisition part acquires the said automatic stop time within the said predetermined time in multiple times. The engine stop / start control device according to any one of claims 1 to 3,
The control unit continues prohibition control for prohibiting the stop of the engine due to establishment of the stop condition until the vehicle enters a resting state, and releases the prohibition control when the vehicle is started again. Start control device.

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