JP5912682B2 - Control device for automatic transmission - Google Patents

Description

  The present invention relates to a control device for an automatic transmission of an engine mounted on an automobile.

  Conventionally, for the purpose of improving fuel consumption by reducing combustion consumption during idling, a technique for mounting an automatic stop / start device called a so-called idling stop has been widely disclosed. In this automatic stop / start device, at the time of restarting, the engine speed is sufficiently increased, and the clutch is engaged after obtaining a hydraulic pressure capable of engaging the clutch of the automatic transmission from an oil pump driven by the engine. Therefore, there is a slight time difference from the start of the engine to the actual start of the vehicle. In recent years, in order to reduce or eliminate the above time difference, it has an electric oil pump that can be driven even when the engine is automatically stopped, and an accumulator that can ensure hydraulic pressure unlike the oil pump, and the clutch is engaged in advance when restarting. A technique of combining them is disclosed (for example, see Patent Document 1).

  However, mounting a different member such as an electric oil pump or an accumulator directly increases the number of parts and the weight.

When performing the restart of the engine, variations occur in the timing of the engine rpm increases. This variation occurs because there are cases where combustion occurs due to the first ignition at the time of restart, and cases where it occurs only after the next ignition, depending on the position of the piston when the engine is stopped. This variation in timing makes the driver feel uncomfortable.

  Further, even when the clutch is engaged before the engine starts rotating at the time of restart as in the above-mentioned patent document, the above-described variation similarly occurs depending on the timing at which the engine starts rotating.

JP 2008-111557 A

  The present invention pays attention to such inconveniences, and aims to effectively improve drivability at the time of restart.

  In order to achieve such an object, the present invention takes the following measures.

That is, the control apparatus for an automatic transmission according to the present invention is a method for controlling an automatic transmission of an engine having an automatic stop / start device, and determines whether or not there is a start delay when the engine is restarted during operation of the automatic stop / start device. If the start delay is caused by the judgment, the gradient of the pressure increase in the sweep section where the pressure of the speed change clutch is gradually increased is set larger than the case where there is no start delay, or the speed change clutch is set prior to the sweep section. By setting the amount of increase when increasing the pressure of the engine to be greater than when there is no start delay, the shift clutch engagement end time is set to a time similar to or close to the time when there is no start delay It is characterized by.

  Here, the concept of “time similar to or close to the time when there is no start delay” is not only the time when the clutch engagement end time is later than the time when there is no start delay, but also at an early time. There may be. That is, the shift clutch is operated with a time difference smaller than the time difference between the engagement end time when there is no start delay and the engagement end time when the start delay occurs and the pressure of the shift clutch is controlled as in the case where there is no start delay. Any mode that terminates the engagement may be used.

  If this is the case, even if there is a delay in starting the engine, the clutch is engaged at the same time as or close to the time when there is no delay in starting the engine. Thus, it is possible to eliminate or reduce the variation in time until the vehicle starts. As a result, the driver can effectively avoid making the driver feel uncomfortable when starting the vehicle at the time of restart. That is, according to the present invention, drivability at restart can be effectively improved.

  ADVANTAGE OF THE INVENTION According to this invention, the drivability at the time of the restart by an automatic stop start apparatus can be improved effectively.

1 is a schematic configuration diagram of an engine according to an embodiment of the present invention. The schematic block diagram of the automatic transmission which concerns on the same embodiment. The time chart which shows the control which concerns on the same embodiment.

  An embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the outline | summary of the engine for vehicles in this embodiment is shown.

  The engine in this embodiment is a spark ignition gasoline 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.

  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 (Continuously Variable Transmission) 9 which is a type of continuously variable transmission are adopted as components of the automatic transmissions 8 and 9. doing.

  The rotational torque output from the engine is input from the crankshaft of the engine to the pump impeller 71 on the input side of the torque converter 7 and 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 the drive wheels (not shown) 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 l and changes its opening.

  Generally, the lock-up mechanism fastens the input side and the output side of the torque converter 7 in a situation that does not involve a change in the gear ratio by the automatic transmissions 8 and 9. During lockup, the lockup clutch 73 is pressed against the torque converter cover 74 and rotates together with the torque converter cover 74. The engine torque input to the input side (drive plate) of the torque converter 7 at the time of lock-up is output from the torque converter cover 74 via the lock-up clutch 73 and thus to the forward / reverse switching device 8. Communicated directly to. At the time of lockup, the speed ratio, which is the ratio of the output side rotational speed of the torque converter 7 to the input side rotational speed, is 1.

  In turn, the lock-up clutch 73 is separated from the torque converter cover 74 at the time of non-lock-up. At the time of non-lock-up, the engine torque input to the input side of the torque converter 7 is transmitted from the torque converter cover 74 to the pump impeller 71 and the turbine 72 and is transmitted to the forward / reverse switching device 8. At the time of non-lock-up, the speed ratio of the torque converter 7 becomes smaller than 1.

  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 shift clutch of the present invention that can be connected and disconnected is interposed. Further, a reverse clutch 85, which is a shift clutch of the present invention that can be connected and disconnected, 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 m 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 axially displaceable. 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.

  A hydraulic pump (hydraulic fluid) supplied to the forward brake 84 or the reverse clutch 85 to operate the travel range, and a hydraulic pump (discharge fluid) supplied to the hydraulic servos 913 and 923 to operate the gear ratio. (Not shown) is a known mechanical (non-electric) type that operates by receiving torque transmitted from the crankshaft of the engine. This hydraulic fluid is common to the fluid used for the torque converter 7.

  An ECU (Electronic Control Unit) 0 that is a control device of 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 (N signal) b output from an engine rotation sensor that detects the rotation angle of the crankshaft and the engine speed, An accelerator opening signal c output from a sensor that detects the amount of depression of the accelerator pedal or the opening of the throttle valve 32 as an accelerator opening (so-called required load), and a brake that is output from a sensor that detects the amount of depression of the brake pedal Stepping amount signal d, intake air temperature / intake pressure signal e output from a temperature / pressure sensor for detecting intake air temperature and intake pressure in intake passage 3 (especially surge tank 33), water temperature sensor for detecting engine cooling water temperature The coolant temperature signal f output from the sensor (or the shift position switch) Shift range signal g outputted from), a cam angle signal (G signal output from the cam angle sensor at a plurality of cam angle of the intake camshaft or an exhaust camshaft) h or the like is input.

  From the output interface, an ignition signal i for the igniter of the spark plug 12, a fuel injection signal j for the injector 11, an opening operation signal k for the throttle valve 32, and a lock for connection / disconnection switching of the lockup clutch 73. An opening control signal 1 is output to the up solenoid valve, an opening control signal m is output to the solenoid valve for switching connection / disconnection of the forward brake 84 or the reverse clutch 85, a gear ratio control signal n is output to the CVT 9, and the like.

  The processor of the ECU 0 interprets and executes a program stored in advance in the memory, calculates an operation parameter, and controls the operation of the engine. The ECU 0 obtains various information a, b, c, d, e, f, g, h necessary for engine operation control via the input interface, knows the engine speed, and fills the cylinder 1 with the intake air. Estimate the quantity. Based on the engine speed and 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, and torque converter 7 lock-up are adjusted. Various operation parameters such as whether to perform the transmission and the gear ratio of the automatic transmissions 8 and 9 are determined. As the operation parameter determination method itself, a known method can be adopted. Thus, the ECU 0 applies various control signals i, j, k, l, m, and n corresponding to the operation parameters via the output interface.

  Further, the ECU 0 inputs a control signal o to a starter motor (cell motor, not shown) when starting the engine (a cold start or a return from an idling stop). Is engaged with the ring gear on the outer periphery of the drive plate to crank the engine. Cranking ends from the first explosion to the consecutive explosion, and ends when the engine speed exceeds a threshold determined according to the cooling water temperature or the like (assuming that the explosion has been completed).

  ECU0 of this embodiment can perform what is called an idling stop by functioning as an automatic stop start device in such a configuration. In executing the idling stop, the ECU 0 stores an idling stop program, and an idling stop condition and a restart condition are set in the idling stop program. The idling stop condition is that at least the charge amount of the battery is equal to or higher than the predetermined charge amount, the outside air temperature is equal to or higher than the predetermined temperature, the engine temperature is equal to or higher than the predetermined temperature, and the vehicle speed is a predetermined speed after the previous idle stop. There is a history of traveling as described above, a predetermined time has elapsed since the last engine start, a predetermined stop time has elapsed since the vehicle stopped, and a predetermined idle time in an idle operation state It has passed and the brake pedal is being depressed. The idling stop is performed when all of these idling stop conditions are satisfied.

  On the other hand, the restart condition is that at least the operation of the brake pedal (for example, depressing) is stopped, the accelerator pedal is operated (for example, depressing), and a predetermined restart time has elapsed since the start of the idling stop. Etc. The restart is performed when at least one of the restart conditions is satisfied. The idling stop condition and the restart condition described above are not limited to the listed items, and those known in this field may be adopted.

  Hereinafter, with reference to the time chart of FIG. 3, the control when the restart condition is established from the idling stop condition according to the present embodiment will be described. The figure shows a control command for brake (brake pedal) behavior, idle stop return signal, engine speed, hydraulic pressure of the forward brake 84 or reverse clutch 85 until the restart condition is established from the idle stop condition to the start of the vehicle. It shows the value and the acceleration that the vehicle moves forward and backward.

  First, when the driver depresses the brake, the ECU 0 issues an idle stop return signal, and the engine is started accordingly. Thereafter, when the increase in the engine speed starts, a signal for increasing the hydraulic pressure of the forward brake 84 or the reverse clutch 85, which is a shift clutch, is issued from the ECU 0 as a clutch pressure control command value.

  In this embodiment, when the restart condition is satisfied from the idling stop condition, it is determined whether there is a start delay when the engine is restarted. For example, such a determination is performed by determining that the time for the engine speed to rise to a predetermined speed is delayed from a predetermined timing, or by determining the ignition and combustion state at the time of restart. Specifically, various modes are conceivable, such as determination by grasping the presence or absence of combustion by the first ignition.

  When the engine start-up delay does not occur, the hydraulic pressure first passes through a constant pressure section a in which only a predetermined pressure c is increased and becomes a constant hydraulic pressure, and then gradually increases with a predetermined gradient d. It becomes a sweep section b. At the end of the sweep section b, the forward brake 84 or the reverse clutch 85, which is a shift clutch, is sufficiently engaged, and the acceleration of the vehicle reaches its peak at that timing.

  Here, the ECU 0 as the control device for the automatic transmissions 8 and 9 according to the present embodiment, when a start delay is caused by the above determination, the pressure of the forward brake 84 as a shift clutch is not delayed when starting. The shift clutch engagement end time is set to a time similar to or close to the time when there is no start delay.

  That is, when a start delay occurs, the timing at which the clutch pressure control command is issued from the ECU 0 is later than when the start delay indicated by the solid line does not occur, as indicated by a broken line in FIG. Therefore, in the present embodiment, first, the hydraulic pressure is increased by c1, which is a value larger than the predetermined pressure c, to obtain a constant pressure section a1. The constant pressure section a1 is a value smaller than the constant pressure section a, that is, a short time. Thereafter, a sweep section b1 in which the hydraulic pressure is gradually increased by a predetermined gradient d1 is set. The gradient d1 is set to a value larger than the gradient d, that is, a value capable of increasing the hydraulic pressure faster than when no start delay occurs. The time of the sweep section b1 is set to a value smaller than the sweep section b, that is, a short time. As a result, the timing for ending the sweep interval b1 is set to be slightly earlier than the timing for ending the sweep interval b. Thereby, the timing at which the acceleration peak of the vehicle relating to forward / reverse travels is substantially the same as the case where the start delay is not generated, in detail, but slightly faster. In addition, after the constant pressure section a1, as shown by the alternate long and short dash line in FIG. In this case, the indicated gradient d2 has a value that is approximately the same as or smaller than the gradient d in the case where the start delay does not occur, but the value is determined by the value of c1.

  By adopting the above-described configuration, the ECU 0 serving as the control device for the automatic transmissions 8 and 9 according to the present embodiment enables the forward brake 84 or the reverse clutch serving as the shift clutch even when the engine start delay occurs. By realizing the engagement at a time similar to or close to the time when there is no start delay in 85, it is possible to eliminate or reduce the variation in time from the start of restart to the actual start of the vehicle. As a result, it is possible to effectively avoid making the driver feel uncomfortable regarding the variation in the timing of starting the vehicle at the time of restart. As a result, drivability during restart from idle stop can be effectively improved.

  In the present embodiment, such an effect can be realized without using any electric oil pump or accumulator that can be driven while the engine is stopped. In other words, it improves drivability without increasing costs by using special elements.

  Although the embodiment of the present invention has been described above, the specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, an aspect in which an electric oil pump or an accumulator is not used is disclosed. However, these may be mounted in order to speed up the start of the vehicle by restart. In the present embodiment, the CVT is applied as an automatic transmission. However, the present invention can also be applied to a case where another stepped transmission is mounted. Further, specific aspects such as the configuration of the engine and control during operation are not limited to those in the above-described embodiment, and various aspects including the existing ones can be applied.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used as a control device for an automatic transmission of an engine mounted on an automobile.

0 ... Automatic transmission control unit (ECU)
8. Automatic transmission (forward / reverse switching device)
84 ... Shift clutch (forward brake)
85 ... shift clutch (reverse clutch)
9 ... Automatic transmission (CVT)

Claims (1)

A control device for an automatic transmission equipped with an automatic stop / start device,
Determines the presence of the starting delay at the time of engine restart during the operation of the automatic stop and start system, when the occurred starting delay by determining the starting delay the gradient of increase in pressure in the sweep period to gradually increase the pressure of the shifting clutch Set the shift clutch engagement end time to a larger value than when there is no delay, or set the amount of increase when increasing the pressure of the shift clutch ahead of the sweep section to be greater than when there is no start delay. A control device for an automatic transmission, characterized in that the time is the same as or close to the time when there is no delay.

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