JP2010112432A - Vehicle controlling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle controlling device capable of promptly starting fuel cut control when going into an idle state. <P>SOLUTION: The vehicle controlling device of a vehicle is equipped with a gear ratio calculating means for calculating a gear ratio on the basis of an accelerator operation variable, a shift control means for carrying out shift control of an automatic change gear on the basis of the calculated gear ratio, and a means for determining whether or not to carry out fuel cut control when going into the idle state by accelerator return operation and a speed of an internal combustion engine is a predetermined engine speed or more. When it is predicted (S4-Y) that the internal combustion engine is going into the idle state on the basis of a variable (S3) changed in response to the accelerator return operation, the gear ratio calculating means calculates (S6) a gear ratio during idling on the basis of the accelerator operation variable, and the shift control means regulates (S9) shift control to the gear ratio during idling when the speed of the internal combustion engine in the gear ratio during idling will become less than the predetermined engine speed (S8-Y) on the basis of the gear ratio during idling and a present vehicle speed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device that executes fuel cut control for stopping the supply of fuel to an internal combustion engine.

  A fuel cut control technique for stopping the supply of fuel to an engine (internal combustion engine) while the vehicle is running is known. As an example of performing fuel cut control, for example, in Patent Document 1, in an accelerator return upshift, a lockup mechanism that operates a lockup clutch during a shift in which the upshift signal is on and delays the start of fuel cut after the shift. A vehicle control device including an automatic transmission is disclosed.

  Further, in Patent Document 2, when the throttle opening of the engine is fully closed and the idle switch is turned on, the target engine speed is increased to correct the transmission ratio to the Low side. A control device for an automatic transmission is disclosed in which when the engine speed decreases due to full closure of the throttle opening, the time required for the engine speed to pass through the fuel cut zone is increased.

JP 2005-98314 A Japanese Patent Laid-Open No. 9-315186

  As in Patent Document 1, when the upshift is performed by the accelerator return operation, the rotational speed of the internal combustion engine decreases. In the case of shifting to steady running by the accelerator return operation, it can be expected that lowering the rotational speed of the internal combustion engine is advantageous in terms of fuel consumption. On the other hand, if an upshift is performed during the accelerator return operation, the start of fuel cut control may be delayed when the accelerator is fully closed. When the engine returns to the idle state by the accelerator return operation, if the rotational speed of the internal combustion engine is reduced due to an upshift, the fuel cut control may not be executed as it is.

  On the other hand, as in Patent Document 2, it is conceivable to set the transmission ratio (gear stage or gear ratio) to the low speed side. For example, it may be possible to increase the rotational speed of the internal combustion engine and perform fuel cut control by performing a downshift after entering the idle state, but the fuel cut control is performed only for the time required for shifting. There is a problem that the execution start is delayed.

  Further, if the downshift is performed immediately after the upshift by the accelerator returning operation, the fuel cut control can be started, but there is a possibility that the shift is busy.

  The objective of this invention is providing the vehicle control apparatus which can start fuel cut control at an early stage, when it will be in an idle state by accelerator return operation.

  Another object of the present invention is to provide a vehicle control device capable of executing fuel cut control while suppressing shifting busy when an idling state is caused by an accelerator return operation.

  A vehicle control apparatus according to the present invention is a shift stage that calculates a shift stage based on a relationship between an internal combustion engine, a stepped automatic transmission, an accelerator operation variable that changes according to an accelerator operation by a driver, and the shift stage. A calculation means, a shift control means for performing a shift control of the automatic transmission based on the calculated shift speed, and at least an idling state by an accelerator return operation by a driver, and a rotational speed of the internal combustion engine is determined in advance; A determination means for determining whether or not to execute fuel cut control for stopping the supply of fuel to the internal combustion engine, and based on a determination result by the determination means, A vehicle control device for controlling a vehicle comprising an execution means for executing cut control, wherein a return operation change that changes in response to an accelerator return operation by the driver. An idle state prediction means for predicting whether or not to enter the idle state based on the current position, and the shift speed calculating means, when predicted to enter the idle state, based on the accelerator operation variable in the idle state An idle speed stage that is higher than the speed stage is calculated, and the shift control means is configured to control the internal combustion engine at the idle speed stage based on the idle speed stage and a vehicle speed variable based on the current vehicle speed. When the rotational speed is less than the predetermined rotational speed, shift control to the idle speed stage is restricted.

  In the vehicle control apparatus according to the present invention, the shift control means calculates a fuel-cuttable shift speed at which the fuel cut control can be executed based on the vehicle speed variable and the predetermined rotation speed, The shift control to the idle shift stage is restricted when the fuel cut enable shift stage is different.

  In the vehicle control apparatus according to the present invention, the shift control means calculates a fuel-cuttable shift speed at which the fuel cut control can be performed based on the vehicle speed variable and the predetermined rotation speed, and calculates the current shift speed and the idle speed. When there is the fuel-cut-capable shift speed between the hour-speed shift speed, shift control to the fuel-cut-capable shift speed is permitted.

  The vehicle control device of the present invention is based on a shift speed calculation means for calculating a shift speed based on the relationship between an accelerator operation variable that changes according to an accelerator operation by the driver and the shift speed, and on the calculated shift speed. A shift control means for performing a shift control of the automatic transmission, and at least when the driver is in an idle state by an accelerator return operation and the rotation speed of the internal combustion engine is equal to or higher than a predetermined rotation speed, Idle state prediction that predicts whether or not to enter an idle state based on a determination unit that determines whether or not to execute fuel cut control for stopping fuel supply and a return operation variable that changes according to an accelerator return operation by the driver Means.

  The shift speed calculating means calculates an idle speed shift speed that is higher than the current shift speed based on the accelerator operation variable in the idle state when the shift speed calculating means When the rotational speed of the internal combustion engine at the idle speed stage is less than a predetermined rotational speed based on the speed stage and the vehicle speed variable based on the current vehicle speed, the shift control to the idle speed stage is restricted. Thereby, the rotational speed of the internal combustion engine in the idle state can be set to a predetermined rotational speed or higher. Therefore, the fuel cut control can be started at an early stage when the engine enters the idle state.

  Hereinafter, an embodiment of a vehicle control device of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The first embodiment will be described with reference to FIGS. 1 to 5. The present embodiment includes an internal combustion engine, a stepped automatic transmission, and a shift speed calculation means for calculating a shift speed based on a relationship between an accelerator operation variable that changes according to an accelerator operation by a driver and the shift speed. A shift control means for performing a shift control of the automatic transmission based on the calculated shift speed, and at least an idling state by an accelerator return operation by the driver, and the rotation speed of the internal combustion engine is equal to or higher than a predetermined rotation speed In this case, determination means for determining whether or not to execute fuel cut control for stopping the supply of fuel to the internal combustion engine, and execution means for executing fuel cut control based on the determination result by the determination means The present invention relates to a vehicle control device that controls a vehicle provided.

The configuration of the present embodiment is premised on the following configurations (A) to (D).
(A) A stepped transmission in which the gear ratio changes stepwise (B) The gear ratio changes not only by the driver's intention, but also a transmission that can automatically shift (C) A configuration that can detect an accelerator operation (D) Fuel injection amount of the engine With a device that can automatically control

  In a vehicle equipped with an automatic transmission, there is a case where a delay in progress to fuel cut occurs due to a foot return upshift. If the engine speed decreases to a low-rotation region where the shift to the fuel cut control cannot be performed due to the foot return upshift, there is a problem that the fuel cut cannot be started until the engine speed is increased by a downshift or the like. On the other hand, in this embodiment, when it is predicted that the accelerator return speed will result in an idle state, by suppressing the upshift, the progress timing to the fuel cut control is advanced and the fuel efficiency is improved.

  In the present embodiment, the determination to shift to fuel cut is predicted before the idling is turned on using the driver's accelerator operation. Specifically, using the rate of change in the amount of accelerator operation (or a factor that can be read by the driver's will, for example, the rate of change in driving force) At the time of return, it is predicted to shift to steady running. If it is determined that there is a shift to fuel cut due to idle ON, the gear stage of the upshift destination by foot return is compared with the gear stage capable of fuel cut control. As a result of the comparison, if it is determined that an immediate fuel cut cannot be executed at the gear position of the upshift destination at the time of idling on, the upshift is prohibited. As a result, a decrease in the engine speed is suppressed, so that fuel cut control can be executed early when idling on, and fuel consumption can be improved.

  FIG. 2 is a schematic configuration diagram of an apparatus according to the present embodiment. In FIG. 2, reference numeral 10 is a stepped automatic transmission, and 40 is an engine (internal combustion engine). The automatic transmission 10 is capable of six-speed shifting by controlling the hydraulic pressure by energization / non-energization of the solenoid valves 121a, 121b, and 121c. In FIG. 2, three electromagnetic valves 121a, 121b, and 121c are illustrated, but the number of electromagnetic valves is not limited to three. The solenoid valves 121a, 121b, and 121c are driven by a signal from the control circuit 130.

  The throttle opening sensor 114 detects the opening of the throttle valve 43 disposed in the intake passage 41 of the engine 40. The throttle opening sensor 114 includes an idle switch that detects whether the opening of the throttle valve 43 is a predetermined value. The idle switch of the throttle opening sensor 114 is turned on when the throttle opening that is the opening of the throttle valve 43 is a value (predetermined value) that is equal to or less than a predetermined opening. On the other hand, the idle switch is turned off when the throttle opening is larger than the predetermined opening. Hereinafter, an idle state in which the idle switch of the throttle opening sensor 114 is ON is described as “idle on”, and a state in which the idle switch is OFF is described as “idle off”. When the idling is on, the idling flag is turned on in the control circuit 130 to be described later, and when the idling is off, the idling flag is turned off in the control circuit 130.

  The engine speed sensor 116 detects the speed (rotational speed) of the engine 40. The vehicle speed sensor 122 detects the rotation speed of the output shaft 120c of the automatic transmission 10 that is proportional to the vehicle speed. The shift position sensor 123 detects the shift position. The accelerator opening sensor 115 detects the opening of an accelerator pedal (not shown). The engine water temperature sensor 119 detects the cooling water temperature of the engine 40.

  The control circuit 130 inputs signals indicating detection results of the throttle opening sensor 114, the accelerator opening sensor 115, the engine speed sensor 116, the engine water temperature sensor 119, the vehicle speed sensor 122, and the shift position sensor 123.

  The control circuit 130 is configured by a known microcomputer and includes a CPU 131, a RAM 132, a ROM 133, an input port 134, an output port 135, and a common bus 136. Signals from the respective sensors 114, 115, 116, 119, 122, and 123 are input to the input port 134. Solenoid valve driving units 138a, 138b, and 138c are connected to the output port 135.

  The ROM 133 stores a program in which the operations (control steps) shown in the flowchart of FIG. 1 are described in advance, and a shift map for shifting the gear stage of the automatic transmission 10 and a shift control operation (not shown). Is stored). The control circuit 130 shifts the automatic transmission 10 based on various input control conditions.

  In addition, the control circuit 130 executes fuel cut control for stopping the supply of fuel to the engine 40 based on various input control conditions. Specifically, the control circuit 130 is at least idling on by an accelerator return operation by the driver, and the engine speed is within a predetermined range (a lower limit speed Ne1 or more described later). Then, it is determined whether or not to execute fuel cut control. In this case, the control circuit 130 determines that the fuel cut control is to be executed when all the fuel cut execution requirements other than the idle switch state and the engine speed are satisfied. On the other hand, the control circuit 130 executes the fuel cut control when the engine is not in the idle state, when the engine speed is less than the lower limit speed Ne1, or when there is something that is not satisfied by other fuel cut execution requirements. Do not judge.

  The control circuit 130 according to the present embodiment includes a shift speed calculation unit that calculates a shift speed based on the relationship between the accelerator operation variable and the shift speed, and a shift that performs shift control of the automatic transmission 10 based on the calculated shift speed. Control means, determination means for determining whether or not to execute fuel cut control, execution means for executing fuel cut control, and prediction of whether or not to enter an idle state based on a return operation variable that changes according to an accelerator return operation It has a function as an idle state prediction means.

  FIG. 3 is a diagram illustrating an example of a shift line as a shift map stored in the ROM 133. In FIG. 3, the vertical axis represents the accelerator opening pap, and the horizontal axis represents the vehicle speed SPD. The shift line defines a correspondence relationship between the accelerator opening degree pap and the vehicle speed SPD as a traveling state and a target gear stage that is a target value of the gear stage (shift stage) of the automatic transmission 10. Here, the accelerator opening degree pap is an accelerator operation variable that changes according to the accelerator operation by the driver. That is, the control circuit 130 calculates the shift speed based on the relationship between the accelerator operation variable set on the shift line and the shift speed.

  In FIG. 3, reference numeral 200 denotes a region 4th of the operating point (combination of the vehicle speed SPD and the accelerator opening pap) at which the fourth speed gear stage (shift stage) is selected in the automatic transmission 10 and the fifth speed gear stage is selected. This is a shift line indicating the boundary with the operating point region 5th. For example, when the current operating point is the operating point indicated by reference numeral P1, the target gear stage of the automatic transmission 10 is set to the fourth speed gear stage. Here, as shown by the arrow Y1, when the driver performs an accelerator return operation and the operating point moves beyond the shift line 200 to the 5th region, the gear stage of the automatic transmission 10 is increased to the fifth gear stage. Shifted. When the accelerator opening degree pap is a low opening degree, an improvement in fuel efficiency can be expected by selecting a high-speed gear stage. For this reason, when the accelerator return operation is performed to shift to the steady running, it is considered that such an upshift is advantageous in terms of fuel consumption.

  However, when the accelerator return operation causes idle on instead of steady running, there is a problem that a time delay until shifting to fuel cut control occurs as will be described with reference to FIG. is there. FIG. 4 is a timing chart showing the operation when the accelerator return operation is performed.

  In FIG. 4, (a) shows the change of the accelerator opening degree pap, and (b) shows the change of the engine speed Ne. The code | symbol 201 shows the accelerator opening degree pap. Reference numeral 202 represents the engine speed Ne in the conventional control. Reference numeral 203 indicates an engine speed Ne when the control of the present embodiment is performed. Reference symbol pap1 denotes an accelerator opening pap corresponding to the predetermined opening, and indicates a threshold value of the accelerator opening pap that is a boundary between idle-on and idle-off. When the accelerator opening degree pap is equal to or smaller than the predetermined opening degree pap1, the idle switch of the throttle opening degree sensor 114 is turned on, and it is determined that the idle is on. The symbol Ne1 is a lower limit value (predetermined rotational speed) of the engine speed Ne at which fuel cut control can be performed. When the engine speed Ne is lower than the lower limit speed Ne1, the control circuit 130 does not determine that the fuel cut control is to be executed.

  When the accelerator opening degree pap (201) decreases at time t0, in the conventional control, an upshift determination based on the shift line is made and the automatic transmission 10 upshifts, and as indicated by reference numeral 202a, the engine speed Ne (202 ) Had fallen. As a result, the engine speed Ne (see reference numeral 202c) immediately before idling is sometimes lower than the lower limit speed Ne1. In this case, even when the accelerator opening degree pap becomes equal to or smaller than the predetermined opening degree pap1 at time t1 and the engine is idling on, the fuel cut control cannot be started immediately. Since the engine is idle-on, the engine speed Ne (202) is increased as shown by reference numeral 202b and the fuel cut control cannot be started until time t2 when the downshift is completed. Thus, there is a possibility that the opportunity to improve fuel efficiency cannot be fully utilized due to the time delay until the shift to the fuel cut control occurs.

  In addition, when a downshift (symbol 202b) is performed after an upshift (symbol 202a) due to an accelerator return, the fuel cut control can be executed, but there is a problem that the shift is busy.

  On the other hand, in this embodiment, it is predicted whether or not the engine will be idle-on by the accelerator return operation, and when it is predicted that the engine will be idle-on, the upshift is restricted. By restricting the upshift, the fuel cut control can be started at an early stage when the engine is idle-on.

  FIG. 5 is a diagram illustrating an example of the transition of the accelerator opening degree pap, and is a diagram for explaining a method of predicting whether or not the engine is idle-on by the accelerator return operation in the present embodiment. In the present embodiment, based on the rate of change (return speed) of the accelerator opening pap in the accelerator return operation, it is predicted whether or not the engine will be idle-on. In other words, based on the rate of change of the accelerator opening degree pap as a return operation variable that changes in response to the accelerator return operation by the driver, it is predicted whether the vehicle will be in an idle state.

  In FIG. 5, reference numeral 204 indicates the accelerator opening pap when the accelerator return operation is performed slowly. Reference numeral 205 indicates an accelerator opening degree pap when a fast accelerator return operation is performed. When the accelerator return operation is performed slowly, it can be predicted that the vehicle will subsequently shift to steady running. This is because, when the driver intends to shift from the acceleration state to the steady running, it is considered that the accelerator returning operation is performed relatively slowly until the accelerator opening degree pap at which the steady running can be realized. is there. As shown by reference numeral 204a, the accelerator return operation is terminated when the vehicle is in a steady running state at an accelerator opening pap larger than the predetermined opening pap1.

  On the other hand, when a quick accelerator return operation is performed, it can be predicted that the driver wants to decelerate and shifts to idle-on. In the present embodiment, in this way, it is predicted (determined) whether or not the accelerator is returned to the idle state based on the change rate of the accelerator opening degree pap in the accelerator return operation. A threshold value b (b ≧ 0) is set for the change rate of the accelerator opening degree pap. In the accelerator return operation, when the magnitude of the change rate of the accelerator opening degree pap (the absolute value of the change rate of the accelerator opening degree pap) is larger than the threshold value b, it is determined that the engine is shifted to the idling-on state.

  If it is determined to shift to idle on, whether or not fuel cut control can be started immediately when the engine is idle on even if an upshift based on the shift line is performed in response to the accelerator return operation. Is determined. Specifically, when the upshift is performed according to the shift line during the accelerator return operation, the gear stage (idle speed stage) that will be selected by the automatic transmission 10 in the running state at the time of idling on, It is compared with a gear stage that can execute fuel cut control when it is on. Compared to a gear stage that can execute fuel cut control, if the gear stage that would have been selected when the engine was idle as a result of the upshift based on the shift line is a high-speed gear stage, in other words, As a result, when the engine speed Ne is predicted to be lower than the lower limit speed Ne1 (see reference numeral 202c in FIG. 4), the upshift is restricted. As a result, the engine speed Ne (203) when the control according to the present embodiment is controlled is prevented from being lower than the lower limit speed Ne1, and fuel cut occurs early after idling on at time t1. Control can be started.

  FIG. 1 is a flowchart showing the operation of this embodiment.

  First, in step S <b> 1, various kinds of information for control are acquired by the control circuit 130. Specifically, the control circuit 130 obtains necessary information such as the detection results of the accelerator opening sensor 115, the throttle opening sensor 114, the engine water temperature sensor 119, and the vehicle speed sensor 122, and the current gear stage of the automatic transmission 10. Obtained.

  Next, in step S2, the control circuit 130 determines whether or not the engine is in an idle-off state. The control circuit 130 performs the determination in step S2 based on the signal indicating the detection result of the throttle opening sensor 114 acquired in step S1, that is, the signal indicating the ON / OFF state of the idle switch. As a result of the determination, if it is determined that the engine is in an idle-off state (step S2-Y), the process proceeds to step S3. If not (step S2-N), the control flow is returned.

  In step S3, the control circuit 130 calculates the change rate a of the accelerator opening degree pap. For example, the control circuit 130 is based on a signal indicating the detection result of the accelerator opening sensor 115 acquired in step S1 and a signal indicating the detection result of the accelerator opening sensor 115 when the present control flow has been executed previously. Thus, the change rate a of the accelerator opening degree pap is calculated. The change rate a of the accelerator opening degree pap is calculated as a positive value when an accelerator depression operation is performed, and is calculated as a negative value when an accelerator return operation is performed.

  Next, in step S4, the control circuit 130 determines whether or not the accelerator is returned quickly so that the rate of change a of the accelerator opening pap calculated in step S3 is equal to or less than a predetermined value (−b). That is, it is determined whether or not the magnitude (absolute value) of the change rate a of the accelerator opening degree pap is larger than the threshold value b and the accelerator return operation is performed (a ≦ 0). As a result of the determination, if it is determined that the accelerator is quickly returned (a <−b) (step S4-Y), the process proceeds to step S5. If not (step S4-N), the control flow returns. Is done. That is, in the case of a slow accelerator return (step S4-N), it is determined that the driver wants to travel steady, and if the upshift requirement is satisfied, the upshift is permitted.

  In step S5, the control circuit 130 determines whether or not a fuel cut establishment condition excluding the idle switch state (idle flag) is satisfied. The control circuit 130 determines whether or not to execute fuel cut control based on the running state such as the engine water temperature, the vehicle speed SPD, and the engine speed Ne including the idle flag. The fuel cut execution requirement for determining that the fuel cut control is to be executed by the control circuit 130 is that the idle flag is ON and parameters such as the engine water temperature, the vehicle speed SPD, and the engine speed Ne are set in advance. It includes that a predetermined condition is satisfied. In step S5, it is determined whether or not the fuel cut execution requirements except for the idle flag state are satisfied.

  The control circuit 130 performs the determination in step S5 based on the engine water temperature detected by the engine water temperature sensor 119, the vehicle speed SPD detected by the vehicle speed sensor 122, and the engine speed Ne detected by the engine speed sensor 116. As a result of the determination, if it is determined that the fuel cut establishment condition excluding the idle flag is satisfied (step S5-Y), the process proceeds to step S6, and if not (step S5-N), this control is performed. The flow is returned.

  In step S <b> 6, the control circuit 130 calculates the upshift gear stage c for foot return. The control circuit 130 reads the upshift gear on the shift line from the current running condition to the time of foot return. Specifically, when the accelerator opening degree pap is reduced to the predetermined opening degree pap1 by the accelerator return operation based on the current running state (running condition) and the shift line as shown in FIG. A command value for the gear position of the automatic transmission 10 is calculated. The gear position of this command value is the backshift upshift gear stage (idle shift stage) c. In other words, the foot-shifting upshift gear stage c is a predicted value of the gear stage when the engine is idling on when the upshift based on the shift line is performed by the accelerator returning operation. That is, the control circuit 130 predicts the traveling state when the idling is turned on, and sets the target gear stage calculated based on the predicted traveling state and the shift line as the upshift gear stage c at the time of foot return. . As shown in FIG. 3, if the operating point indicated by the reference symbol P1 is the current operating point and the accelerator return operation indicated by the arrow Y1 is performed, the estimated value of the gear stage when the engine is idle-on is obtained. The return upshift gear stage c is a fifth gear stage.

  Next, in step S7, the control circuit 130 calculates the highest gear stage d that can shift to fuel cut control. The control circuit 130 determines the highest gear stage d that can be shifted to the fuel cut control, which is the fastest gear stage among the gear stages that can be shifted to the fuel cut control from the current vehicle speed SPD or the rotation speed of the output shaft 120c. calculate. As indicated by reference numerals SPD4 and SPD5 in FIG. 3, regions of the vehicle speed SPD that can shift to fuel cut control are set in advance for each gear stage. Reference numeral SPD4 indicates an area of the vehicle speed SPD that can be shifted to the fuel cut control at the fourth speed gear stage, and reference numeral SPD5 indicates an area of the vehicle speed SPD that can be shifted to the fuel cut control at the fifth speed gear stage. The region of the vehicle speed SPD that can be shifted to the fuel cut control can be calculated based on the region of the engine speed Ne that can be shifted to the fuel cut control and the gear ratio of each gear stage.

  The control circuit 130 performs fuel cut control on the gear speed at which the engine speed Ne is equal to or higher than the lower limit speed Ne1, based on the vehicle speed SPD as the vehicle speed variable or the rotation speed of the output shaft 120c and the gear ratio of each gear speed. It is determined that the gear stage can be executed. Of the gear stages capable of executing fuel cut control, the highest gear stage is the highest gear stage d capable of shifting to fuel cut control.

  If the accelerator return operation (arrow Y1) is performed from the current operating point P1, if it is upshifted to the fifth gear, it is impossible to shift to fuel cut control when idling on, but the fourth gear remains as it is. If there is, it is possible to shift to fuel cut control when idling is on. In this case, the highest gear stage d that can be shifted to the fuel cut control is calculated as the fourth gear stage.

  Next, in step S8, the control circuit 130 determines whether or not the upshift gear stage c for returning the gear is a gear stage on the high speed side as compared with the highest gear stage d that can shift to fuel cut control. The The control circuit 130 makes a determination in step S8 based on the comparison result between the foot-shifting upshift gear stage c calculated in step S6 and the highest gear stage d that can be shifted to the fuel cut control calculated in step S7. I do. If the backshift upshift gear stage c is a higher gear stage than the highest gear stage d that can be shifted to fuel cut control, the fuel cut control is started immediately when the engine is idle-on. Can not do it. For this reason, the control which suppresses an upshift is made by step S9 mentioned later. On the other hand, when the upshift gear stage c for returning the foot is coincident with the highest gear stage d that can be shifted to the fuel cut control or the gear stage is on the lower speed side than the highest gear stage d that can be shifted to the fuel cut control. Even if an upshift based on the shift line is performed in response to the accelerator return operation, the fuel cut control can be promptly shifted to the idle cut-on state. For this reason, the upshift is not suppressed.

  As a result of the determination in step S8, when it is determined that the upshift gear stage c for returning the foot is a higher gear stage than the highest gear stage d that can be shifted to the fuel cut control (step S8-Y). If not (step S8-N), the process proceeds to step S10.

  In step S <b> 9, the upshift is suppressed by the control circuit 130. The control circuit 130 restricts the execution of the upshift even if the upshift determination based on the shift line is performed according to the accelerator return operation. As a result, an upshift to a higher gear than the current gear is suppressed. As a result, a decrease in the engine speed Ne due to the upshift is suppressed, and the fuel cut control can be started promptly when idling.

  In step S10, the control circuit 130 determines whether or not the engine is idle on. The control circuit 130 performs the determination in step S10 based on a signal indicating the state of the idle switch input from the throttle opening sensor 114. As a result of the determination, if it is determined that the engine is idling on (step S10-Y), the process proceeds to step S11. If not (step S10-N), the control flow is returned.

  In step S11, the fuel cut control is executed by the control circuit 130. The fuel cut control for stopping the supply of fuel to the engine 40 is performed by the control circuit 130. When step S11 is executed, this control flow is returned.

  According to the present embodiment, when an accelerator return operation is performed, it is predicted whether or not the engine will be idle-on and then shift to fuel cut control during the accelerator return operation. (1) “When it is predicted that the engine will be idle-on and an upshift based on the shift line is made, the gear stage on the higher speed side than the gear stage that can shift to fuel cut control at the time of idle-on. In the case where it is predicted that this will occur, the upshift is restricted. As a result, it is possible to suppress the start of the fuel cut control from being delayed at the time of idling, and to advance fuel cut control to improve fuel efficiency.

  On the other hand, (2) “when it is not predicted that the engine will be idle on”, or (3) “although it is predicted that the engine will be idle, but shifts to fuel cut control when the engine is idle even if an upshift based on the shift line is performed. If it is predicted that there will be a possible gear, the upshift is not restricted. In the case of (2) above, that is, when it is predicted that the vehicle will shift to steady running by the accelerator return operation, the fuel consumption can be improved by performing the upshift. Further, in the case of (3) above, the situation of proceeding to the upshift regulation is limited in the scene where it is predicted that the engine will be idle-on because the upshift regulation is not performed. The restriction of the upshift can be limited to a case where fuel consumption can be improved by restricting the upshift. In other words, when the upshift is restricted, the upshift can be restricted only when the start timing of the fuel cut control can be advanced at the time of idling, as compared with the case where the upshift is not restricted.

  In addition, in the conventional control, when the accelerator is operated to upshift to a gear position that cannot be shifted to fuel cut control based on the shift line, the fuel cut control is performed by performing a downshift after idling on. It was possible to start. However, in this case, there is a possibility that the shift is busy because the downshift is performed after the upshift. On the other hand, according to the present embodiment, in the case of (1), the shift to the fuel cut control can be performed at the time of idling while suppressing the shift shift by restricting the upshift. it can.

  In the present embodiment, whether or not the engine is idle-on is determined based on the change rate of the accelerator opening degree pap, but the determination criterion is not limited to the change rate. For example, as long as it represents the degree of change in the accelerator opening pap, such as an integrated value of the change in the accelerator opening pap within a predetermined time, it can be used as a criterion for determining whether or not the engine is idle-on.

  In addition, the parameter for determining whether or not the engine is idling on is not limited to the accelerator opening degree pap. For example, a parameter that reflects the driver's intention, such as a required driving force, can be used as a parameter for determining whether or not the engine is idle-on.

(First modification of the first embodiment)
A first modification of the first embodiment will be described.

  In the first embodiment (FIG. 1), when the upshift gear stage c for returning the gear is a higher gear stage than the highest gear stage d capable of shifting to fuel cut control (step S8-Y). Only upshifts were restricted (step S9). Instead, the upshift is restricted regardless of whether or not the upshift gear stage c for returning the foot is a higher gear stage than the highest gear stage d that can be shifted to the fuel cut control. Also good. In other words, when it is predicted that the accelerator is turned back on by the accelerator returning operation, the upshift is regulated without comparing the upshift gear stage c for returning the foot and the highest gear stage d capable of shifting to the fuel cut control. You may make it do. Even if it does in this way, the fall of an engine speed can be suppressed and it can transfer to fuel cut control early at the time of idling. In this case, steps from Step S6 to Step S8 are omitted in the flowchart of FIG.

(Second modification of the first embodiment)
A second modification of the first embodiment will be described.

  In the first embodiment (FIG. 1), when the upshift gear stage c for returning the gear is a higher gear stage than the highest gear stage d capable of shifting to fuel cut control (step S8-Y). In this case, an upshift to a higher gear than the current gear was prohibited. Instead of this, upshifting may be permitted (allowed) as long as it is within a range of gears that can shift to fuel cut control when idling.

  For example, when the current gear stage is the fourth gear stage, the upshift gear stage c for returning the foot is the sixth gear stage, and the highest gear stage d that can be shifted to the fuel cut control is the fifth gear stage. Upshifts up to the fifth gear stage may be permitted, and upshifts to higher gear stages beyond the sixth gear stage may be restricted. Thus, drivability can be improved by giving priority to the target gear stage calculated based on the shift line as much as possible. For example, the actual deceleration (engine braking force) matches the deceleration requested by the driver.

(Third Modification of First Embodiment)
A third modification of the first embodiment will be described.

  In the first embodiment (FIG. 1), whether or not the upshift is restricted based on the comparison result between the upshift gear stage c for returning to the idle speed and the highest gear stage d capable of shifting to fuel cut control. However, instead of this, every time a shift request is made during the accelerator return operation, it may be determined whether or not to restrict the upshift. For example, when an upshift from the fourth gear to the fifth gear is requested during the accelerator return operation, the fifth gear is compared with the highest gear d that can shift to fuel cut control, It can be determined whether or not to restrict the upshift. The upshift is restricted when the fifth gear is a gear on the higher speed side than the highest gear d that can shift to fuel cut control. Even if it does in this way, there can exist an effect similar to the 2nd modification of the said 1st Embodiment.

(Second Embodiment)
The second embodiment will be described with reference to FIGS. 6 and 7. In the second embodiment, only differences from the first embodiment will be described.

  In the first embodiment, the case where the automatic transmission 10 is stepped and the gear ratio changes stepwise has been described. However, the automatic transmission 10 may be a continuously variable transmission. In the case of a stepped automatic transmission, whether or not the fuel cut control can be executed at the idle speed is determined based on the gear ratio of the idle speed. That is, whether or not the fuel cut control can be executed is determined by the speed ratio calculated based on the accelerator operation variable in the idle state and the speed change line. Judgment can be made. Even if the automatic transmission 10 is a continuously variable transmission, as in the case of a stepped transmission, when it is predicted that the engine will be idle-on by an accelerator return operation, the fuel cut is controlled by restricting the upshift. The start timing of control can be advanced, and fuel consumption can be reduced.

  FIG. 6 is a timing chart showing the operation when the control of this embodiment is performed.

  In FIG. 6, (c) shows the change of the accelerator opening degree pap, and (d) shows the change of the engine speed Ne. Reference numeral 301 indicates an accelerator opening degree pap. Reference numeral 302 indicates the engine speed Ne in the conventional control. Reference numeral 303 indicates the engine speed Ne when the control of this embodiment is performed. Further, symbol pap2 is a predetermined opening similar to the predetermined opening pap1 of the first embodiment, and indicates a threshold value of the accelerator opening pap serving as a boundary between idle-on and idle-off. The symbol Ne2 is a lower limit value of the engine speed Ne that can execute the fuel cut control similar to the lower limit speed Ne1 of the first embodiment.

  The control circuit 130 stores a predetermined shift line of the continuously variable automatic transmission 10, and calculates a target gear ratio (target gear ratio) of the automatic transmission 10 based on the shift line. The shift line defines, for example, the correspondence between the vehicle speed and the target value of the engine speed Ne (the input shaft speed of the automatic transmission 10) according to the accelerator opening. When the accelerator opening is lowered, the target gear ratio is changed to the high speed side gear ratio. In other words, when the accelerator return operation is performed, the upshift of the automatic transmission 10 is determined. Thereby, in the conventional control, when the accelerator opening degree pap (301) decreases from time t0 to time t1, the engine speed Ne (302) decreases due to the upshift. As indicated by reference numeral 302a, when the engine rotational speed Ne (302) decreases and becomes lower than the lower limit rotational speed Ne2, even if the engine is idle-on at time t1, it immediately shifts to fuel cut control. I could not. The fuel cut control could not be started until the time t3 when the engine speed Ne (302) reached the lower limit speed Ne2 after the engine was idled and the engine speed Ne (302) reached the lower limit speed Ne2.

  On the other hand, as in the first embodiment, in the present embodiment, when it is predicted that the engine is idle-on by the accelerator return operation and an upshift based on the shift line is performed, If it is predicted that the gear ratio will be higher than the gear ratio that can be shifted to the fuel cut control at the time of ON, the upshift is prohibited. As a result, the engine speed Ne (303) when the control according to the present embodiment is performed remains higher than the lower limit speed Ne2. Therefore, fuel cut control can be started promptly at time t1 when idling is on.

  FIG. 7 is a flowchart showing the operation of this embodiment.

  Steps S21 to S25 can be the same as steps S1 to S5 in the first embodiment. That is, various information for control is acquired (step S21), it is determined that the engine is idling off (step S22-Y), and the rate of change a of the accelerator opening degree pap is calculated (step S23). Then, it is determined whether or not the accelerator is returned quickly (a <−b) (step S24). If it is determined that the accelerator is quickly returned (step S24-Y) and the fuel cut establishment condition excluding the idle flag is satisfied (step S25-Y), the process proceeds to step S26.

  In step S26, the control circuit 130 calculates the upshift gear ratio e for foot return. The control circuit 130 determines the gear of the automatic transmission 10 when the accelerator opening degree pap is reduced to the predetermined opening degree pap2 by the accelerator returning operation based on the current driving state (driving condition) and the previously stored shift line. The ratio command value (target gear ratio) is calculated. The gear ratio of this command value is the upshift gear ratio e for foot return.

  In step S27, the control circuit 130 calculates the highest gear ratio f that can shift to fuel cut control. The control circuit 130 determines the highest gear ratio f that can be shifted to the fuel cut control that is the highest gear ratio among the gear ratios that can be shifted to the fuel cut control from the current vehicle speed SPD or the rotation speed of the output shaft 120c. calculate.

  Next, in step S28, the control circuit 130 determines whether or not the upshift gear ratio e for returning is higher than the highest gear ratio f that can be shifted to the fuel cut control. . As a result of the determination, if it is determined that the upshift gear ratio e for returning is higher than the highest gear ratio f that can be shifted to the fuel cut control (step S28-Y). The process proceeds to step S29, and if not (step S28-N), the process proceeds to step S30.

  In step S29, the upshift is suppressed by the control circuit 130. The control circuit 130 restricts the execution of the upshift even if the upshift determination based on the shift line is performed according to the accelerator return operation. As a result, an upshift to a higher gear ratio than the current gear ratio is suppressed. As a result, a decrease in the engine speed Ne due to the upshift is suppressed, and the fuel cut control can be started promptly when idling.

  Steps S30 and S31 can be the same as steps S10 and S11 of the first embodiment. That is, when it is determined that the engine is idle on (step S30-Y), fuel cut control is executed (step S31). When step S31 is executed, this control flow is returned.

  According to the present embodiment, when an accelerator return operation is performed, it is predicted whether or not the engine will be idle-on and then shift to fuel cut control during the accelerator return operation. (4) “When the engine is predicted to be idle-on and an upshift based on the shift line is made, the gear ratio on the higher speed side than the gear ratio that can be shifted to fuel cut control at the time of idle-on. In the case where it is predicted that this will occur, the upshift is restricted. As a result, similarly to the first embodiment, it is possible to suppress the delay of the start of the fuel cut control at the time of idling on, and to advance the fuel cut control to accelerate the fuel consumption.

  On the other hand, (5) “when it is not predicted that the engine will be idle-on” or (6) “although it is predicted that the engine will be idle-on, the shift to fuel cut control is performed when the engine is idle even if an upshift based on the shift line is made If it is predicted that the gear ratio is possible, upshifts are not restricted. As a result, as in the first embodiment, the fuel efficiency when shifting to steady running is improved, or the upshift is restricted only when the fuel consumption can be improved by restricting the upshift. Can do.

  Further, in the case of (4) above, the upshift is restricted, so that it is possible to shift to the fuel cut control at the time of idling while suppressing shifting busy.

(First Modification of Second Embodiment)
A first modification of the second embodiment will be described.

  In the second embodiment (FIG. 7), when the upshift gear ratio e for foot return is a higher gear ratio than the highest gear ratio f that can be shifted to fuel cut control (step S28-Y). Only upshifts were restricted (step S29). Instead, the upshift is regulated regardless of whether or not the upshift gear ratio e of the foot return is a gear ratio on the high speed side as compared with the highest gear ratio f that can be shifted to the fuel cut control. Also good. In other words, when it is predicted that the accelerator is turned back on by the accelerator returning operation, the upshift is restricted without comparing the upshift gear ratio e for returning the foot and the highest gear ratio f that can be shifted to the fuel cut control. You may make it do. Even if it does in this way, the fall of an engine speed can be suppressed and it can transfer to fuel cut control early at the time of idling. In this case, steps from step S26 to step S28 are omitted in the flowchart of FIG.

(Second Modification of Second Embodiment)
A second modification of the second embodiment will be described.

  In the second embodiment (FIG. 7), when the upshift gear ratio e for foot return is a higher gear ratio than the highest gear ratio f that can be shifted to fuel cut control (step S28-Y). Was prohibited from upshifting to a higher gear ratio than the current gear ratio. Alternatively, upshifting may be permitted as long as it is within the range of the gear ratio that can be shifted to the fuel cut control when idling.

  Since the target gear ratio calculated based on the shift line is given priority as much as possible, drivability can be improved. For example, the actual deceleration (engine braking force) more closely matches the deceleration requested by the driver.

It is a flowchart which shows operation | movement of 1st Embodiment of the vehicle control apparatus of this invention. It is a schematic block diagram of the apparatus which concerns on 1st Embodiment of the vehicle control apparatus of this invention. It is a figure which shows an example of the shift line as a shift map stored in ROM of 1st Embodiment of the vehicle control apparatus of this invention. It is a timing chart which shows operation | movement when accelerator return operation is made | formed in 1st Embodiment of the vehicle control apparatus of this invention. It is a figure for demonstrating the method to predict whether it will become idle-on by accelerator return operation in 1st Embodiment of the vehicle control apparatus of this invention. It is a timing chart which shows operation in case control of a 2nd embodiment of a vehicle control device of the present invention is performed. It is a flowchart which shows operation | movement of 2nd Embodiment of the vehicle control apparatus of this invention.

Explanation of symbols

10 Automatic transmission 40 Engine (internal combustion engine)
43 throttle valve 114 throttle opening sensor 115 accelerator opening sensor 116 engine speed sensor 119 engine water temperature sensor 122 vehicle speed sensor 123 shift position sensor 130 control circuit P1 current operating point pap accelerator opening pap1, pap2 predetermined opening Ne engine rotation Number Ne1, Ne2 Lower limit speed SPD Vehicle speed SPD4, SPD5 Vehicle speed range that can be shifted to fuel cut control

Claims (3)

An internal combustion engine;
A stepped automatic transmission,
A shift speed calculation means for calculating a shift speed based on the relationship between an accelerator operation variable and a shift speed that change according to the accelerator operation by the driver;
Shift control means for performing shift control of the automatic transmission based on the calculated shift speed;
At least fuel cut control is performed to stop fuel supply to the internal combustion engine when the driver is in an idle state by an accelerator return operation and the rotational speed of the internal combustion engine is equal to or higher than a predetermined rotational speed. Determining means for determining whether to do;
A vehicle control device that controls a vehicle including an execution unit that executes the fuel cut control based on a determination result by the determination unit;
Idle state prediction means for predicting whether to enter the idle state based on a return operation variable that changes according to the accelerator return operation by the driver,
When the shift speed calculating means is predicted to be in the idle state, the shift speed calculating means calculates an idle speed shift speed that is higher than the current shift speed based on the accelerator operation variable in the idle state,
The shift control means, when the rotational speed of the internal combustion engine at the idle speed stage is less than the predetermined rotational speed based on the idle speed stage and a vehicle speed variable based on the current vehicle speed, A vehicle control device that regulates shift control to a stage. The vehicle control device according to claim 1,
The shift control means calculates a fuel-cuttable shift speed at which the fuel-cut control can be performed based on the vehicle speed variable and the predetermined rotation speed, and the idle shift speed and the fuel-cuttable shift speed are different. In this case, the vehicle control device restricts the shift control to the idle speed stage. The vehicle control device according to claim 1 or 2,
The shift control means calculates a fuel-cuttable shift speed at which the fuel cut control can be performed based on the vehicle speed variable and the predetermined rotational speed, and between the current shift speed and the idle shift speed, When there is a fuel cut-capable shift stage, the shift control to the fuel cut-capable shift stage is permitted.

Images