JP2016151327A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an improper rise of an engine rotation number resulting from an operation of a gear change ratio of an automatic transmission.SOLUTION: A control device of a vehicle operates a gear change ratio of an automatic transmission which is interposed between an internal combustion engine and wheels so that a preset engine rotation number and engine torque are obtained in response to an output which is required to the internal combustion engine. When a pedal-in amount of an accelerator pedal is not smaller than a prescribed amount, and an increase amount of the pedal-in amount of the accelerator pedal per unit time is not smaller than a prescribed amount, the control device operates a gear change ratio of an automatic transmission so as to be shifted to a high-gear side so that an engine rotation number which is lower than a preset engine rotation number is obtained, and after that, when the pedal-in amount of the accelerator pedal reaches the prescribed amount or smaller, the control device restores control to control for operating the gear change ratio of the automatic transmission so that the prescribed engine rotation number and the engine torque are obtained.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a control device for a vehicle including an internal combustion engine and an automatic transmission.

  Recent automobiles are often AT cars equipped with automatic transmissions. As an automatic transmission for a vehicle, a continuously variable transmission including a torque converter and a belt-type continuously variable transmission mechanism is known (for example, refer to the following patent document).

  The gear ratio of the automatic transmission is controlled so as to realize optimum fuel consumption performance in accordance with the fuel consumption rate (fuel consumption rate) characteristics of the internal combustion engine. As shown in FIG. 3, when the engine speed is taken on the horizontal axis and the engine torque is taken on the vertical axis, the equal output line where the output of the internal combustion engine, which is the product of the engine speed and the engine torque, becomes constant is a broken line. It is drawn in the form of a hyperbola (represented by a broken line) as shown. Furthermore, a set of the engine speed and engine torque at which the fuel consumption rate is constant is drawn as an equal fuel consumption rate line represented by a thin solid line. By combining these two, it is possible to plot the gear ratio that provides the best fuel efficiency when achieving a certain output for various outputs. That is the optimal fuel consumption line represented by a thick solid line. A vehicle-mounted electronic control unit (Electronic Control Unit) operates the gear ratio of the automatic transmission along the optimum fuel consumption line in accordance with increase / decrease in the required output (required load) commanded by the driver.

JP 2013-177947 A

  It is difficult for the driver to accurately predict the running resistance of the vehicle from time to time. Therefore, the required output to the internal combustion engine, such as when the driver depresses the accelerator pedal unnecessarily strongly, then gradually depresses the accelerator pedal and then depresses the accelerator pedal again during actual vehicle travel. The vibrational change of can occur. If the control device that controls the automatic transmission operates the gear ratio so as to strictly follow the fluctuation of the required output, the engine speed increases so as to increase instantaneously, resulting in a decrease in fuel consumption performance. There was a thing.

  The present invention has been made by paying attention to the above-mentioned problem for the first time, and an object of the present invention is to suppress an inappropriate increase in the engine speed caused by the operation of the gear ratio of the automatic transmission.

  In the present invention, the speed ratio of the automatic transmission interposed between the internal combustion engine and the axle is manipulated so as to realize a predetermined engine speed and engine torque corresponding to the output required for the internal combustion engine. When the amount of depression of the accelerator pedal is equal to or greater than a predetermined amount and the amount of increase in the amount of depression of the accelerator pedal per unit time is equal to or greater than a predetermined value, the control device is configured to reduce the engine speed lower than a predetermined engine speed. When the automatic transmission gear ratio is operated closer to the higher gear, and the accelerator pedal is depressed below a predetermined level, the engine speed and the engine torque are automatically set. The vehicle control device is configured to return to the control for operating the transmission gear ratio.

  In addition, in the present invention, the speed ratio of the automatic transmission interposed between the internal combustion engine and the axle is set so as to realize a predetermined engine speed and engine torque corresponding to the output required for the internal combustion engine. When the accelerator pedal depression amount is greater than or equal to a predetermined value and the amount of increase in the accelerator pedal depression amount per unit time is greater than or equal to a predetermined value, the engine speed is lower than a predetermined engine speed. If the speed ratio of the automatic transmission is operated closer to the high gear so as to embody the number, and the accelerator pedal depression amount continues to be greater than or equal to a predetermined value even after a predetermined period, a predetermined engine speed The vehicle control device is configured to return to the control for operating the gear ratio of the automatic transmission so as to realize the number and the engine torque.

  According to the present invention, an inappropriate increase in the engine speed due to the operation of the gear ratio of the automatic transmission can be suppressed.

The figure which shows the structure of the internal combustion engine for vehicles and control apparatus in one Embodiment of this invention. The figure which shows the structure of the drive system of the vehicle in the embodiment. The figure which shows the relationship between an engine speed, an engine torque, an engine output, and a fuel consumption rate, and the gear ratio of an automatic transmission. The timing diagram which shows the content of the control which the control apparatus of the embodiment implements.

  An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the outline | summary of the internal combustion engine 100 for vehicles in this embodiment is shown. The internal combustion engine 100 according to the present embodiment is a spark ignition type four-stroke engine and includes a plurality of cylinders 1 (one of which is shown in FIG. 1). In the vicinity of the intake port of each cylinder 1, an injector 11 for injecting fuel is provided. A spark plug 12 is attached to the ceiling of the combustion chamber of each cylinder 1. The spark plug 12 receives spark voltage generated by the ignition coil and causes spark discharge between the center electrode and the ground electrode. The ignition coil is integrally incorporated in a coil case together with an igniter that is a semiconductor switching element.

  The intake passage 3 for supplying intake air takes in air from the outside and guides it to the intake port of each cylinder 1. On the intake passage 3, an air cleaner 31, an electronic throttle valve 32, a surge tank 33, and an intake manifold 34 are arranged in this order from the upstream.

  The exhaust passage 4 for discharging the exhaust guides the exhaust generated as a result of burning the fuel in the cylinder 1 from the exhaust port of each cylinder 1 to the outside. An exhaust manifold 42 and an exhaust purification three-way catalyst 41 are disposed on the exhaust passage 4.

  An external EGR (Exhaust Gas Recirculation) device 2 realizes a so-called high-pressure loop EGR. The EGR device 2 includes an external EGR passage 21 that communicates the upstream side of the catalyst 41 in the exhaust passage 4 and the downstream side of the throttle valve 32 in the intake passage 3, an EGR cooler 22 provided on the EGR passage 21, and an EGR passage 21. And an EGR valve 23 that controls the flow rate of the EGR gas flowing through the EGR passage 21. The inlet of the EGR passage 21 is connected to the exhaust manifold 42 in the exhaust passage 4 or a predetermined location downstream thereof. The outlet of the EGR passage 21 is connected to a predetermined location downstream of the throttle valve 32 in the intake passage 3, specifically to a surge tank 33.

  FIG. 2 shows an example of a drive system provided in the vehicle. This drive system includes a torque converter 7 and automatic transmissions 8 and 9. In particular, in the present embodiment, a forward / reverse switching device 8 using a planetary gear mechanism and a belt type CVT 9 which is a type of continuously variable transmission are adopted as components of the automatic transmissions 8 and 9.

  The rotational torque output from the internal combustion engine 100 is input from the crankshaft, which is the output shaft of the internal combustion engine 100, to the pump impeller 71 on the input side of the torque converter 7, and is transmitted to the turbine runner 72 on the output side. The rotation of the turbine runner 72 is transmitted to the drive shaft 94 of the CVT 9 via the forward / reverse switching device 8 and rotates the driven shaft 95 through a shift in the CVT 9. The rotation of the driven shaft 95 is transmitted to the output gear 101. The output gear 101 meshes with the ring gear 102 of the differential device, and rotates the axle 103 and thus the driving wheel via the differential device.

  The torque converter 7 includes a lockup mechanism. The lock-up mechanism is known in this field, and a lock-up clutch 73 that fastens the input side and the output side of the torque converter 7 so as not to rotate relative to each other, and an operation for switching the connection of the lock-up clutch 73. A lock-up solenoid valve (not shown) for controlling the hydraulic pressure (hydraulic pressure) is used as an element. The lockup solenoid valve is a flow rate control valve that receives a control signal o and changes its opening.

  In a vehicle equipped with CVT 9, when the vehicle speed is a predetermined value (for example, 10 km / h) or more, the torque converter 7 is almost always locked up. When the vehicle speed is equal to or lower than the predetermined value, the lockup of the torque converter 7 is released.

  In the forward / reverse switching device 8, the sun gear 81 communicates with the turbine runner 72, and the ring gear 82 communicates with the drive shaft 94. Between the planetary carrier 83 that supports the planetary gear 831 and the transmission case, a forward brake 84 that is a hydraulic clutch that can be connected and disconnected is interposed. Further, a reverse clutch 85, which is a hydraulic clutch capable of switching connection / disconnection, is also interposed between the planetary carrier 83 and the sun gear 81 (or the output side of the torque converter 7).

  In the D range of the traveling range, the forward brake 84 is engaged and the reverse clutch 85 is disconnected. As a result, the rotation of the output shaft of the torque converter 7 is reversed and decelerated and transmitted to the drive shaft 94 for forward travel. In turn, in the R range, the reverse clutch 85 is engaged and the forward brake 84 is disconnected. As a result, the sun gear 81 and the planetary carrier 83 rotate integrally, and the output shaft of the torque converter 7 and the drive shaft 94 are directly connected to perform reverse travel. A solenoid valve (not shown) that controls the hydraulic pressure for driving the forward brake 84 or the reverse clutch 85 to connect / disconnect is a flow rate control valve that receives a control signal p and changes its opening.

  In the N range and P range, which are non-traveling ranges, both the forward brake 84 and the reverse clutch 85 are disconnected.

  The CVT 9 includes a driving pulley 91 and a driven pulley 92, and a belt 93 wound around the pulleys 91 and 92 as elements. The drive pulley 91 is disposed behind the movable sheave 912, a fixed sheave 911 fixed to the drive shaft 94, a movable sheave 912 supported on the drive shaft 91 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 913 is provided, and the gear ratio can be changed steplessly by operating the hydraulic servo 913 and displacing the movable sheave 912. The driven pulley 92 is disposed on the back of the movable sheave 922, a fixed sheave 921 fixed to the driven shaft 95, a movable sheave 922 supported on the driven shaft 95 via a roller spline so as to be displaceable in the axial direction. A hydraulic servo 923 is provided, and a belt thrust necessary for torque transmission is applied by operating the hydraulic servo 923 and displacing the movable sheave 922.

  The hydraulic fluid (hydraulic fluid) supplied to the forward brake 84 or the reverse clutch 85 to operate the travel range and the hydraulic fluid supplied to the hydraulic servos 913 and 923 to operate the gear ratio are used for the torque converter 7. It is common with the fluid to be used. This fluid is referred to as transmission fluid (CVTF). The transmission fluid is also used for lubrication of the forward / reverse switching device 8 and the belt 93 of the CVT 9 and for preventing sliding friction of the belt 93 with respect to the pulleys 91 and 92.

  The ECU 0 serving as a vehicle control device according to the present embodiment is a microcomputer system having a processor, a memory, an input interface, an output interface, and the like.

  The input interface includes a vehicle speed signal a output from a vehicle speed sensor that detects the actual vehicle speed of the vehicle, a crank angle signal b output from an engine rotation sensor that detects the rotation angle and engine speed of the crankshaft, and depression of an accelerator pedal. An accelerator opening signal c output from a sensor that detects the amount or the opening degree of the throttle valve 32 as an accelerator opening degree (so-called required output and required load for the internal combustion engine 100), and output from a sensor that detects the depression amount of the brake pedal The brake pedal depression amount signal d, the intake air temperature / intake pressure signal e output from the intake air temperature / intake pressure sensor for detecting the intake air temperature and the intake pressure in the intake passage 3 (particularly, the surge tank 33), the internal combustion engine 100 The coolant temperature signal f output from the coolant temperature sensor that detects the coolant temperature, the temperature of the transmission fluid in the drive train The fluid temperature signal g output from the fluid temperature sensor for detecting the battery, the battery status signal h output from the sensor for detecting the indicator (battery current and / or battery voltage) indicating the charge state of the on-vehicle battery, and the like are input. The

  From the output interface, the ignition signal i for the igniter of the spark plug 12, the fuel injection signal j for the injector 11, the opening operation signal k for the throttle valve 32, and the opening operation signal l for the EGR valve 23. , The opening control signal o for the lockup solenoid valve for switching connection / disconnection of the lockup clutch 73, and the opening control signal p, CVT9 for the solenoid valve for switching connection / disconnection of the forward brake 84 or the reverse clutch 85. On the other hand, a gear ratio control signal q and the like are output.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates operation parameters, and controls the operation of the internal combustion engine 100. The ECU 0 acquires various information a, b, c, d, e, f, g, and h necessary for operation control of the internal combustion engine 100 via the input interface, knows the engine speed, and is filled in the cylinder 1. Estimate the amount of intake air (fresh air). Based on the engine speed, the intake air amount, etc., the required fuel injection amount, fuel injection timing (including the number of times of fuel injection for one combustion), fuel injection pressure, ignition timing, required EGR rate (or EGR rate) Amount), whether or not to lock up the torque converter 7, and various operating parameters such as the gear ratio of the CVT 9 are determined. The ECU 0 applies various control signals i, j, k, l, o, p, q corresponding to the operation parameters via the output interface.

  FIG. 3 shows the relationship between the engine speed, the engine torque, the engine output, the fuel consumption rate (fuel consumption rate), and the optimum fuel consumption line that is the shift line of the CVT 9. In FIG. 3, a thin broken line represents an equal output line at which the engine output is constant, and a thin chain line represents an equal fuel consumption line (contour line of fuel consumption rate) at which the fuel rate of the internal combustion engine 100 is constant. In addition, a thick solid line represents an optimum fuel consumption line that is a shift line of the CVT 9 in normal gear ratio control.

  The ECU 0 includes a current accelerator opening and vehicle speed, various auxiliary devices mounted on the vehicle (a generator that operates by receiving drive torque from the internal combustion engine 100, a compressor for compressing refrigerant in an air conditioner, a cooling water pump, An engine output and an engine torque required for the internal combustion engine 100 are estimated in accordance with a load by a lubricating oil pump or the like (not shown), friction loss of the internal combustion engine 100 and the drive system, and the like. The required engine torque tends to be higher as the accelerator opening is larger, the vehicle speed is lower, the loads on various auxiliary machines are higher, and the cooling water temperature and the transmission fluid temperature are lower.

  Normally, the ECU 0 operates the gear ratio of the CVT 9 to a value on the optimum fuel consumption line corresponding to the required output at that time, in other words, a value on the optimum fuel consumption line corresponding to the engine speed and engine torque at that time. . That is, the transmission ratio of the CVT 9 in the normal transmission ratio control varies along the optimum fuel consumption line represented by the thick solid line in FIG. The optimum fuel consumption line is selected from values of the engine speed and engine torque that achieve a certain engine output, and the value at which the fuel consumption rate is minimized or close to the minimum (the fuel consumption performance is good) is selected. The values are plotted.

  In addition, the ECU 0 controls the intake (fresh air) amount and the fuel injection amount charged in the cylinder 1 so that the estimated required engine torque can be achieved. The intake air amount can be controlled through the operation of the opening degree of each of the throttle valve 32 and the EGR valve 23 and the opening / closing timing of the intake valve. The fuel injection amount can be controlled through manipulation of the valve opening time and the number of valve opening times of the injector 11.

  By the way, when the vehicle is actually running, the amount of depression of the accelerator pedal is such that the driver depresses the accelerator pedal unnecessarily strongly, then immediately depresses the accelerator pedal and then re-presses the accelerator pedal again. May change to vibrate or pulsate. Such a driving operation is equivalent to frequently changing the required output to the internal combustion engine 100. When the gear ratio of the CVT 9 is operated along the optimal fuel consumption line so as to completely follow this, the engine speed is instantaneous. There is a risk of a sudden increase in fuel efficiency.

  A specific example will be described. Assuming a situation in which the required output for the internal combustion engine 100 increases from O1 to O2 and then returns to O1 in a short time, according to the conventional gear ratio control, the gear ratio of the CVT 9 is optimized from the point P1 on the optimum fuel consumption line. A transition is made to the point P2 along the line, and after that, the point P2 is returned again to the point P1 along the optimum fuel consumption line in a short time. As a result, as indicated by a chain line in FIG. 4, an event occurs in which the engine speed rapidly increases by ΔNe between point P1 and point P2 and then rapidly decreases. As the engine speed increases, the fuel consumption increases and the fuel efficiency deteriorates.

  Therefore, the ECU 0 of the present embodiment has an accelerator pedal depression amount that is greater than or equal to a predetermined amount (for example, the accelerator opening is 30% or more of the fully open position) for the purpose of suppressing an unnecessary rapid increase in engine speed, and the accelerator pedal is When the increase amount per unit time of the depression amount exceeds a predetermined value, the gear ratio of the CVT 9 is deliberately operated to a value deviating from the optimum fuel consumption line.

  In a situation where the required output for the internal combustion engine 100 increases from O1 to O2, if the condition that the amount of depression of the accelerator pedal is equal to or greater than a predetermined value and the amount of increase in the amount of depression of the accelerator pedal per unit time is satisfied, the ECU 0 A point P3 at which the transmission ratio of CVT 9 is not on the intersection P2 between the equal output line O2 and the optimum fuel consumption line, but on the equal output line O2 and in higher gear than the optimum fuel consumption line (the reduction ratio becomes smaller). To operate. At the same time, in order to ensure the necessary engine output, the intake (fresh air) amount and fuel injection amount charged in the cylinder 1 are increased and corrected so that the engine torque becomes a point P3 that is higher than the point P2. That is, the throttle valve 32 is opened more widely, the EGR valve 23 is opened smaller, and / or the intake valve timing is advanced. This control pattern is shown by a solid line in FIG. After that, when the amount of depression of the accelerator pedal becomes less than a predetermined value and the required output to the internal combustion engine 100 decreases from O2 to O1, the gear ratio of the CVT 9 and the engine torque, that is, the intake air amount and the fuel injection amount are controlled normally. Is returned to the point P1 on the optimum fuel consumption line which is the value at. As a result of this control, the amount of increase in the engine speed is suppressed between the points P1 and P3, so that the fuel consumption does not increase and the fuel efficiency is improved.

  Further, after the CVT 9 gear ratio and engine torque are operated to the point P3 deviating from the optimum fuel consumption line, if the accelerator pedal depression amount continues to be greater than or equal to the predetermined value even after the predetermined period has elapsed, the ECU 0 The speed ratio and the engine torque are manipulated to a point P2 on the optimum fuel consumption line corresponding to the required output O2 at that time. The speed ratio and engine torque from point P3 to point P2 are shifted as much as possible along the iso-output line O2, and the deviation between the actual output of the internal combustion engine 100 and the required output is suppressed below a certain level. . The point P2 is equal to the set of the gear ratio and the engine torque that are implemented to achieve the required output O2 in normal control. Compared with the point P3, the transmission ratio of the CVT 9 at the point P2 becomes lower gear (the reduction ratio becomes larger), and the engine torque becomes lower torque. That is, in the process from the point P3 to the point P2, the ECU 0 throttles the throttle valve 32 to a smaller degree, opens the EGR valve 23 to a larger degree, and / or retards the intake valve timing more. Thus, the intake (fresh air) amount and the fuel injection amount charged in the cylinder 1 are reduced to normal control amounts.

  In the present embodiment, it is interposed between the internal combustion engine 100 and the axle 103 so as to embody a predetermined engine speed and engine torque (on the optimum fuel consumption line) corresponding to the output required for the internal combustion engine 100. In the control device 0 for operating the transmission ratio of the automatic transmission 9, when the amount of depression of the accelerator pedal is equal to or greater than a predetermined value and the amount of increase in the amount of depression of the accelerator pedal per unit time is equal to or greater than a predetermined value, The gear ratio of the automatic transmission 9 is operated closer to the high gear so as to realize an engine speed lower than the engine speed (on the optimum fuel consumption line), and then the accelerator pedal depression amount becomes a predetermined amount or less. Sometimes, the vehicle that returns to the control that operates the speed ratio of the automatic transmission 9 so as to embody the predetermined engine speed and engine torque (on the optimum fuel consumption line). To constitute a control device 0.

  According to the present embodiment, the accelerator pedal is operated in a driving region where the driver can step on the accelerator pedal strongly in a short time and the operation for easily releasing the depression is repeated, for example, in a driving region where the accelerator opening is 30% or more fully opened. When the increase amount per unit time is greater than or equal to a predetermined amount, it is possible to suppress an increase in the engine speed while increasing the engine torque as compared to the case where it is not. Accordingly, it is possible to suppress an increase in fuel consumption due to an inappropriate rapid increase in engine speed, which can contribute to an improvement in practical fuel consumption. Since the inertia of the internal combustion engine 100 is larger than the inertia of the CVT 9, reducing the fluctuation of the engine rotation by operating the gear ratio of the CVT 9 greatly leads to reduction of energy loss, that is, improvement of efficiency.

  In addition, in the present embodiment, the internal combustion engine 100 and the axle 103 are configured so as to embody a predetermined engine speed and engine torque (on the optimum fuel consumption line) corresponding to the output required for the internal combustion engine 100. Is a control device 0 for operating the gear ratio of the automatic transmission 9 intervening in the case where the amount of depression of the accelerator pedal is equal to or larger than a predetermined value and the amount of increase in the amount of depression of the accelerator pedal per unit time is equal to or larger than a predetermined value. The accelerator pedal is operated closer to the high gear so as to realize an engine speed lower than a predetermined engine speed (on the optimum fuel consumption line), and an accelerator pedal is operated even after a predetermined period of time elapses. Of the automatic transmission 9 so as to embody a predetermined engine speed and engine torque (on the optimum fuel consumption line) when the amount of depression of the engine continues to exceed a predetermined amount. To constitute a control apparatus 0 of the vehicle to return to the control to operate the.

  According to this embodiment, when the state where the amount of depression of the accelerator pedal continues for a predetermined time or more continues for a certain period of time, for example, when traveling on an uphill or trying to pass another vehicle on a highway, the engine rotation The number and the engine torque can be quickly returned from values deviating from the optimum fuel consumption line to values near the optimum fuel consumption line, which can contribute to improvement of practical fuel consumption.

  The present invention is not limited to the embodiment described in detail above. For example, the specific mode of the automatic transmission mounted on the vehicle is arbitrary, and is not limited to the belt type CVT 9.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to control of an internal combustion engine and an automatic transmission mounted on a vehicle.

0 ... Control unit (ECU)
DESCRIPTION OF SYMBOLS 100 ... Internal combustion engine 103 ... Axle 1 ... Cylinder 11 ... Injector 23 ... EGR valve 32 ... Throttle valve 9 ... Automatic transmission (CVT)

Claims (2)

A control device for operating a gear ratio of an automatic transmission interposed between an internal combustion engine and an axle so as to embody a predetermined engine speed and engine torque corresponding to an output required for the internal combustion engine. And
Automatic shift so that the engine speed is lower than the predetermined engine speed when the amount of accelerator pedal depression exceeds a predetermined value and the amount of accelerator pedal depression increases per unit time or more. While operating the gear ratio of the machine closer to high gear,
Thereafter, when the amount of depression of the accelerator pedal becomes equal to or less than a predetermined value, the vehicle control device returns to the control for operating the speed ratio of the automatic transmission so as to embody a predetermined engine speed and engine torque. A control device for operating a gear ratio of an automatic transmission interposed between an internal combustion engine and an axle so as to embody a predetermined engine speed and engine torque corresponding to an output required for the internal combustion engine. And
Automatic shift so that the engine speed is lower than the predetermined engine speed when the amount of accelerator pedal depression exceeds a predetermined value and the amount of accelerator pedal depression increases per unit time or more. While operating the gear ratio of the machine closer to high gear,
If the accelerator pedal depressing amount continues to be greater than or equal to a predetermined amount after a predetermined period of time has elapsed, the control returns to the control for operating the gear ratio of the automatic transmission so as to embody the predetermined engine speed and engine torque. A vehicle control device.

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