JP2015172414A - Vehicle controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle controller capable of accurately detecting the timing of increasing the number of revolutions of a turbine, that is, the timing of gradually increasing engagement oil pressure of frictional engagement elements and achieving both gear shift responsiveness and suppression of gear shift shock even if the actual number of revolutions of the turbine increases by, for example, downgrade or disturbance from a road surface at a time of downshifting an automatic transmission.SOLUTION: A controller of a vehicle mounting thereon an internal combustion engine and an automatic transmission that transmits rotational power output from the internal combustion engine by grip-changing a plurality of frictional engagement elements, switching power transmission passes, and shifting gears, starts gradually increasing the engagement oil pressure of the frictional engagement elements on a condition that the sign of an average change rate of a differential number of revolutions obtained by subtracting the number of revolutions of a turbine from the synchronized number of revolutions before gear shift changes from a positive sign to a negative sign in the downshifting process of the automatic transmission.

Description

  The present invention relates to a vehicle control device.

  2. Description of the Related Art Conventionally, there is known a control device for a hybrid vehicle including a stepped automatic transmission that appropriately transmits rotational power generated by an engine or an electric motor to driving wheels according to the traveling state of the vehicle (for example, a patent Reference 1).

  The hybrid vehicle control device disclosed in Patent Document 1 includes a synchronous rotational speed of an input rotational speed of the automatic transmission calculated from an actual output rotational speed of the automatic transmission and a speed ratio before the shift, The start of the inertia phase in the downshift process of the automatic transmission is determined based on the difference rotational speed from the actual input rotational speed of the automatic transmission (see, for example, paragraph 0013 of Patent Document 1). ).

International Publication No. 2012/095970

  However, what is disclosed in Patent Document 1 discloses a synchronous rotational speed of an input rotational speed of the automatic transmission calculated from an actual output rotational speed of the automatic transmission and a speed ratio before the shift, and the automatic transmission. The start of the inertia phase in the downshift process of the automatic transmission is determined based on the difference rotational speed from the actual input rotational speed of the automatic transmission, and the actual input rotational speed of the automatic transmission is, for example, from a downhill or a road surface There was a problem that it was not taken into account that it was rising due to the disturbance of the sword.

  For this reason, when the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface, it is erroneously determined that the input rotational speed of the automatic transmission has turned to the positive side, and the friction on the engagement side There has been a problem that a shift shock may occur due to a shift in timing of gradually increasing the engagement pressure of the engagement element.

  The present invention has been made in order to solve the above-described problem. In the downshift of the automatic transmission, the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface. Even in such a case, it is possible to accurately detect the timing at which the turbine rotational speed is increased, that is, the timing at which the engagement hydraulic pressure of the friction engagement element gradually increases, and control of the vehicle that can achieve both shift response and shift shock suppression. The purpose is to provide a device.

  In order to solve the above-described problems, the vehicle control apparatus of the present invention (1) changes speed by switching the power transmission path of the internal combustion engine and the rotational power output from the internal combustion engine by changing a plurality of friction engagement elements. In the vehicle control apparatus equipped with the automatic transmission, the sign of the average change rate of the differential rotational speed obtained by subtracting the turbine rotational speed from the synchronous rotational speed before shifting is positive in the downshift process of the automatic transmission. On the condition that the switching is negative, sweeping up of the engagement hydraulic pressure of the friction engagement element on the engagement side is started.

  With this configuration, when the automatic transmission is downshifted, even when the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface, the timing for increasing the turbine rotational speed, that is, The timing of gradually increasing the engagement hydraulic pressure of the friction engagement element can be accurately detected, and both shift response and shift shock suppression can be achieved.

  According to the present invention, when the automatic transmission is downshifted, the timing at which the turbine rotational speed is increased even when the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface. In other words, it is possible to provide a vehicle control device that can accurately detect the timing of gradually increasing the engagement hydraulic pressure of the friction engagement element and can achieve both shift response and shift shock suppression.

It is a figure explaining the schematic structure of the power transmission path | route which comprises the vehicle to which this invention is applied, and is a figure explaining the principal part of the control system provided in the vehicle. It is an operation | movement table | surface of the automatic transmission which comprises the vehicle to which this invention is applied. It is a block diagram which shows the structure of control systems, such as ECU which comprises the control apparatus of the vehicle to which this invention is applied. It is a timing chart which shows an example of the downshift transmission control in the control apparatus of the vehicle of this invention. It is a figure explaining the hydraulic circuit part which implements the downshift transmission control from the 2nd speed to the 1st speed in the vehicle control apparatus of the present invention. It is a flowchart which shows an example of the sweep-up control performed in the case of the downshift transmission control in the control apparatus of the vehicle of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a power transmission path constituting a vehicle to which the present invention is applied, and a diagram illustrating a main part of a control system provided in the vehicle. A vehicle to which the present invention is applied includes an engine 1 as an internal combustion engine that is a travel drive source, a starting device that includes a torque converter 2 and a lock-up clutch 25, an automatic transmission 5, an ECU 100, and a hydraulic control circuit 300. The vehicle control device of this embodiment is realized by a program executed by the ECU 100. Each part of the engine 1, the torque converter 2, the automatic transmission 5, the ECU 100, the hydraulic control circuit 300, and the like will be described below.

  The engine 1 mixes and introduces fuel with intake air into the combustion chamber, ignites, burns, and explodes, and converts the reciprocating motion of the piston as the rotation of the crankshaft by the connecting rod to convert the input shaft of the torque converter 2. To communicate.

  The rotational speed of the crankshaft 11 (engine rotational speed Ne) is detected by, for example, an electromagnetic pickup type engine rotational speed sensor 201 that generates a pulse signal (output pulse) corresponding to the rotation of the crankshaft 11.

  The ECU 100 determines the optimum intake air amount (target intake air amount) according to the engine operating state such as the engine rotational speed Ne detected by the engine rotational speed sensor 201 and the accelerator pedal depression amount (accelerator opening) of the driver. As shown, the throttle opening of a throttle valve (not shown) is controlled through drive control of the throttle motor 13 (see FIG. 3).

  The starting device includes a torque converter 2 and a lockup clutch 25. As shown in FIG. 1, the torque converter 2 includes a pump impeller 21 that inputs rotation of an input shaft, a turbine runner 22 that is rotated in response to a flow of hydraulic oil from the pump impeller 21, and oil from the turbine runner 22. And a one-way clutch 24.

  The rotation of the stator 23 is fixed by the one-way clutch 24 in a state where the rotation of the turbine runner 22 is lower than the rotation of the pump impeller 21. The stator 23 receives the reaction force of the oil flow and produces a torque increasing effect. When the rotation of the oil reaches a state where the rotation of the oil exceeds, the oil is idled so that the oil flow does not act in the negative direction.

  The torque converter 2 performs power transmission for amplifying torque between the pump impeller 21 and the turbine runner 22 via a fluid.

  The lock-up clutch 25 is provided between the main body of the torque converter 2 and the turbine runner 22, and is driven and controlled so that the turbine runner 22 is engaged and released by a hydraulic control circuit 300 controlled by the ECU 100. Is done.

  When the lockup clutch 25 is completely engaged by the hydraulic control circuit 300, the input side and the output side of the torque converter 2 are integrated, that is, the output shaft of the engine 1 and the input shaft of the automatic transmission 5 are connected. Let it be in a directly connected state.

  Therefore, the pump impeller 21 and the turbine runner 22 rotate integrally. Further, by engaging the lockup clutch 25 in a predetermined slip state, the turbine runner 22 rotates following the pump impeller 21 with a predetermined slip amount during driving.

  The torque converter 2 and the automatic transmission 5 are connected by a rotating shaft. The turbine speed Nt of the torque converter 2 is detected by the turbine speed sensor 202. The turbine speed sensor 202 detects the turbine speed Nt from the number of pulses of a clutch drum (not shown) that rotates in the same manner as the input shaft 30 of the automatic transmission 5, for example.

  The automatic transmission 5 includes an automatic transmission mechanism 3 in a case (mission case) 6. The automatic transmission mechanism 3 has an input shaft 30 connected to the output shaft of the torque converter 2 and an output shaft 34 connected to a drive wheel (not shown). The input shaft 30 and the output shaft 34 The first and second clutches C1 and C2, the first and second and third brakes B1 to B3, the one-way clutch F1, the first planetary gear (transmission gear mechanism) 31, the second planetary gear ( (Transmission gear mechanism) 32, third planetary gear (transmission gear mechanism) 33, and the like.

  The first planetary gear mechanism 31 is configured by a single pinion planetary gear including a carrier CR1 that rotatably supports the pinion P1, a sun gear S1 that meshes with the pinion P1, and a ring gear R1, respectively.

  The second planetary gear mechanism 32 is constituted by a single pinion planetary gear that includes a carrier CR2 that rotatably supports the pinion P2, a sun gear S2 that meshes with the pinion P2, and a ring gear R2, respectively.

  The third planetary gear mechanism 33 is constituted by a single pinion planetary gear that includes a carrier CR3 that rotatably supports the pinion P3, a sun gear S3 that meshes with the pinion P3, and a ring gear R3.

  The power output from the output shaft 34 of the automatic transmission 5 is transmitted to the drive wheels via a propeller shaft, a differential gear, a drive shaft, and the like. The first and second clutches C1 and C2 and the first, second and third brakes B1 to B3 are driven by a hydraulic control circuit 300 controlled by the ECU 100.

  The sun gear S1 of the first planetary gear mechanism 31 of the automatic transmission 5 is connected to the input shaft 30 and is rotated integrally with the input shaft 30. The carrier CR1 that rotatably supports the pinion P1 of the first planetary gear mechanism 31 is selectively connected to the case 6 via the first brake B1, and the carrier CR1 is connected to the ring gear R2 of the second planetary gear mechanism 32. Connected together. The ring gear R1 of the first planetary gear mechanism 31 is selectively connected to the case 6 via the third brake B3.

  The sun gear S2 of the second planetary gear mechanism 32 is integrally connected to the sun gear S3 of the third planetary gear mechanism 33, and is selectively connected to the input shaft 30 via the first clutch C1.

  The carrier CR2 of the second planetary gear mechanism 32 is integrally connected to the ring gear R3 of the third planetary gear mechanism 33, and is selectively connected to the input shaft 30 via the second clutch C2. , Selectively coupled to the case 6 via the second brake B2. The carrier CR2 is always prevented from rotating in the reverse direction by the one-way clutch F1 provided in parallel with the second brake B2.

  The carrier CR3 of the third planetary gear mechanism 33 is integrally connected to the output shaft. The rotational speed of the output shaft 34 of the automatic transmission 5 is detected by an output rotational speed sensor 203.

  The engagement / release state of the first and second clutches C1 and C2 and the first, second and third brakes B1 to B3 of the automatic transmission 5 is shown in the operation table of FIG. In the operation table of FIG. 2, “◯” represents “engagement”, “blank” represents “release”, and “「 ”represents“ engagement during engine braking ”.

  As shown in FIG. 2, in the automatic transmission 5 of this example, at the first speed (1st) of the forward gear stage, the first clutch C1 is engaged and the carrier CR2 is always in the reverse direction by the one-way clutch F1. Rotation is prevented.

  Then, when the engine brake is in the first gear (1st) of the forward gear stage, the one-way clutch F1 does not work and the second brake B2 is engaged while the first clutch C1 remains engaged. . In the second speed (2nd) of the forward gear, the first clutch C1 and the first brake B1 are engaged.

  At the third forward speed (3rd), the first clutch C1 is engaged and the third brake B3 is engaged. In the fourth speed (4th) of the forward gear, the first and second clutches C1 and C2 are engaged.

  At the fifth forward speed (5th), the second clutch C2 is engaged and the third brake B3 is engaged. At the sixth forward speed (6th), the second clutch C2 is engaged and the first brake B1 is engaged.

  The automatic transmission 5 configured as described above includes five friction engagement elements C1, C2, and B1 to B3, and the forward sixth speed as a plurality of shift stages is determined by the engagement / disengagement state of these engagement elements. And the first planetary gear mechanism 32, and the one-way clutch F1 that restricts the one-way rotation of the ring gear R3 of the second planetary gear mechanism 33 and the CR2 of the second planetary gear mechanism 32. This is a multi-stage automatic transmission in which a first gear is established as a low gear at the time of positive driving that transmits drive rotation from the side to the output shaft 34 side.

  In the automatic transmission 5, the second brake B2 is in the low speed stage during reverse driving, that is, during reverse driving in which the one-way clutch F1 is idling and the driving rotation is transmitted from the output shaft 34 side to the input shaft 30 side. This is the brake that is engaged to achieve (that is, the first-speed engine brake).

  With reference to the operation | movement table | surface of FIG. 2, the release side engagement element and engagement side engagement element which perform the re-holding in the case of a downshift are demonstrated. Here, the disengagement-side engagement element is an engagement element that is currently in an engaged state and is in a released state after shifting, and the engagement-side engagement element is in a currently released state and after shifting Is an engaging element that is in an engaged state.

  As shown in the operation table of FIG. 2, when the downshift is performed, the first brake B1 is released and the third brake B3 is engaged when downshifting from the sixth speed to the fifth speed. When downshifting from the fifth speed to the fourth speed, the third brake B3 is released and the second clutch C2 is engaged. When downshifting from the fourth speed to the third speed, the second clutch C2 is released and the third brake B3 is engaged. When downshifting from the third speed to the second speed, the third brake B3 is released and the first brake B1 is engaged. When downshifting from the second speed to the first speed, the first brake B1 is released and the second brake B2 is engaged.

  On the other hand, a shift device (not shown) is arranged in the vicinity of the driver's seat of the vehicle. The shift device is set to a P (parking) position, an R (reverse) position, an N (neutral) position, and a D (drive) position by manually displacing the shift lever. Each position is detected by a shift position sensor 205 (see FIG. 3). An output signal from the shift position sensor 205 is input to the ECU 100.

  The P position and the N position are non-traveling positions that are selected when the vehicle is not traveling, the D position is a traveling position that is selected when the vehicle travels forward, and the R position is the vehicle that travels backward. This is the travel position that is sometimes selected.

  When the P position or the N position is selected by the shift lever, as shown in FIG. 2, the first and second clutches C1, C2 and the first, second, and third brakes B1 to B1 of the automatic transmission 5 are provided. All of B3 and the one-way clutch F1 are released, and the output shaft 34 is locked by a parking mechanism (not shown).

  When the D position is selected, an automatic transmission mode for automatically shifting the automatic transmission 5 according to the driving state of the vehicle is set, and a plurality of forward gears (sixth forward speed) of the automatic transmission 5 are automatically set. Shift control is performed. When the R position is selected, the automatic transmission 5 is switched to the reverse gear.

  In addition, when the shift lever is operated to the M position, a manual shift mode (sequential mode) for performing a manual shift operation is set, and when the shift lever is operated to upshift or downshift in this manual shift mode. The gear stage of the automatic transmission 5 is increased or decreased by one stage for each operation.

  Further, the operation signals of the upshift switch and the downshift switch provided on the steering wheel provided in front of the driver's seat of the vehicle are input to the ECU 100. For example, when the shift lever is operated to the D position, for example, every time the downshift switch 208 is operated, the gear position of the automatic transmission 5 is lowered by one stage, and the upshift switch is operated once. Every time, the gear stage of the automatic transmission 5 is increased.

  As shown in FIG. 3, the ECU 100 includes a CPU 101, a ROM 102, a RAM 103, a backup RAM 104, and the like.

  The ROM 102 stores various programs including a program for executing a shift control for setting the gear stage of the automatic transmission 5 in accordance with the traveling state of the vehicle, in addition to the control related to the basic driving of the vehicle. . Specific contents of this shift control will be described later.

  The CPU 101 executes arithmetic processing based on various control programs and maps stored in the ROM 102. The RAM 103 is a memory that temporarily stores calculation results in the CPU 101, data input from each sensor, and the backup RAM 104 is a non-volatile memory that stores data to be saved when the engine 1 is stopped. It is.

  The CPU 101, ROM 102, RAM 103, and backup RAM 104 are connected to each other via a bus 107, and are connected to an input interface 105 and an output interface 106.

  The input interface 105 includes an engine speed sensor 201, a turbine speed sensor 202, an output speed sensor 203, an accelerator position sensor 204 that detects the position of the accelerator pedal 4, a shift position sensor 205, and a vehicle speed. A vehicle speed sensor 206, an upshift switch 207, a downshift switch 208, and the like are connected, and signals from these various sensors are input to the ECU 100.

  The output interface 106 is connected to the throttle motor 13 that drives the throttle valve, the injector 26, the hydraulic pressure control circuit 300, and the like.

  The ECU 100 includes an engine 1 including throttle valve opening control, ignition timing control (igniter drive control), fuel injection amount control (injector 26 opening / closing control) and the like based on the output signals of the various sensors described above. Various controls are executed.

  The ECU 100 also outputs a solenoid control signal (hydraulic instruction signal) for setting the gear position of the automatic transmission 5 to the hydraulic control circuit 300. On the basis of this solenoid control signal, the excitation / non-excitation of the linear solenoid valve and the ON-OFF solenoid valve of the hydraulic control circuit 300 is controlled so that a predetermined shift gear (1st to 6th) is established. Control is performed so that the first and second clutches C1 and C2, the first and second brakes B1 to B3, the one-way clutch F1 and the like of the automatic transmission 5 shift to a predetermined state.

  Further, the ECU 100 outputs a lockup clutch control signal (hydraulic instruction signal) to the hydraulic control circuit 300. Based on the lock-up clutch control signal, the lock-up control valve of the hydraulic control circuit 300 is controlled, and the lock-up clutch 25 of the torque converter 2 is engaged, half-engaged or released.

[Control of ECU 100]
The ECU 100 executes <shift control using a shift map>, <control during downshift>, and the like described below. The ECU 100 constitutes a vehicle control device according to the present invention.

<Shift control using shift map>
When the D position is selected and the automatic shift control mode is selected, the ECU 100 always determines whether the target gear stage is different from the current gear stage using the shift map stored in the ROM 102, When they are different, shift control is performed.

  This shift map uses the vehicle speed and the accelerator opening as parameters, and according to them, a switching line that upshifts the gear stage for each of the first to sixth gear stages for obtaining the gear stage that provides the optimum fuel efficiency. A region defined by an upshift line and a downshift line that is a switching line for downshifting the gear stage is set.

  The ECU 100 calculates the vehicle speed V from the output signal of the vehicle speed sensor 206, calculates the accelerator opening Acc from the output signal of the accelerator opening sensor 204, and is stored in the ROM 102 based on the vehicle speed V and the accelerator opening Acc. The target gear stage is calculated with reference to the shift map, and the target gear stage is compared with the current gear stage to determine whether or not a shift operation is necessary. The vehicle speed V may be calculated from the output signal of the output rotation speed sensor 203.

  The ECU 100, for example, when the running state of the vehicle changes from, for example, a downshift shift line [5 → 4] from a situation where the gear stage of the automatic transmission 5 is running in the “5-speed” state. Outputs a solenoid control signal (hydraulic instruction signal) for setting the fourth gear to the hydraulic control circuit 300 to shift from the fifth gear to the fourth gear (5 → 4 downshift). Control to do.

  When there is no need for shifting (when the target gear stage and the current gear stage are the same and the gear stage is appropriately set), the ECU 100 controls a solenoid control signal (hydraulic instruction signal) that maintains the current gear stage. Is output to the hydraulic control circuit 300.

  In addition, when the shift lever is operated to upshift or downshift in the manual shift mode, or when the upshift switch or the downshift switch is operated, the ECU 100 responds to the manual shift request with a solenoid control signal (hydraulic pressure). (Instruction signal) is output to the hydraulic control circuit 300 so that the automatic transmission 5 is controlled to establish a gear stage.

<Shift control during downshift>
Next, the shift control during downshift will be specifically described with reference to the timing chart of FIG.

  In FIG. 4, the shift output means that the ECU 100 outputs a change instruction to the hydraulic control circuit 300 in order to change from the current gear stage to a gear stage that is lower by the first gear. The shift output is, for example, a solenoid control signal (output from the ECU 100 to the hydraulic control circuit 300 when the ECU 100 determines that the shift lever is operated once to the downshift position in the manual shift mode in which the M position is selected. Hydraulic pressure instruction signal).

  The ECU 100, for example, when a downshift speed change output (N speed → [N−1] speed) is generated, as shown in the operation table of FIG. A solenoid control signal is output to the hydraulic control circuit 300 so as to perform gripping.

  First, the ECU 100 causes the hydraulic pressure control circuit 300 to quickly reduce the hydraulic pressure instruction value (release hydraulic pressure in FIG. 4) of the release side engagement element to 0 with a predetermined change pattern, while Control is performed so that the hydraulic pressure instruction value of the combined element (engagement hydraulic pressure in FIG. 4) is changed according to a predetermined change pattern.

  As a release hydraulic pressure instruction to the release-side engagement element, the ECU 100 vertically lowers the release-side engagement element from the engagement pressure to a predetermined first fill pressure Pf at the elapsed time t1 immediately after the shift output. The slip engagement state is set, and the first fill pressure Pf is maintained for a short time until the elapsed time t2, and further, the hydraulic pressure is gradually decreased to the release pressure for a short time until the elapsed time t3. As a result, the release-side engagement element is in a completely released state.

  Further, the ECU 100 instructs the engagement side engagement element to reach the predetermined first fill pressure Pf at the elapsed time t2 as an engagement hydraulic pressure instruction to the engagement side engagement element, and slips the engagement side engagement element from the fully released state. The engaged state is set, and the first fill pressure Pf is held for a very short time until the elapsed time t3. At the elapsed time t3, the engagement hydraulic pressure is reduced to a predetermined constant pressure standby pressure Pt, and then the constant pressure standby pressure Pt is set. Instruct to hold until elapsed time t6.

  The ECU 100 performs sweep-up control as an engagement hydraulic pressure instruction to the engagement side engagement element (the brake B2 in FIG. 5). The sweep-up rate when performing the sweep-up control is created as a map for each of the first to sixth gears and stored in the ROM 102. The ECU 100 performs sweep-up control from the elapsed time t6 to t10 at a sweep-up rate corresponding to the torque-up amount that is adapted to the vehicle speed V calculated based on the map.

  As for the aforementioned sweep-up rate, a torque-up amount (blipping amount) adapted to the vehicle speed is stored in the ROM in advance. This sweep-up rate is experimentally determined in advance. For example, the sweep-up rate is set so that the torque-up amount becomes smaller as the vehicle speed increases.

  On the other hand, as shown in FIG. 4, the ECU 100 continuously inputs the turbine rotation speed Nt as a shift output. The turbine rotational speed Nt matches the synchronous rotational speed before the shift until the time t4 after the hydraulic pressure instruction to the engagement side engaging element becomes the constant pressure standby pressure Pt after the shift output is generated. From the time point of elapsed time t4, it gradually dissociates from the synchronous rotational speed before the shift and decreases, but then stabilizes at a constant rotational speed, and after the elapsed time t7, it matches the synchronous rotational speed after the shift. Ascending characteristic curve.

  Further, as shown in the flow of FIG. 6 described later, the ECU 100 calculates a differential rotation speed Nts4x obtained by subtracting the turbine rotation speed Nt from the synchronous rotation speed before shifting. According to the results of many measurements, as shown in FIG. 4, the differential rotation speed Nts4x is 0 rotation from the time of shifting output until the elapsed time t4, gradually increases from the elapsed time t4 to t5, and then passes. From time t5 to t8, a characteristic curve that gradually decreases after being stabilized for a shorter time than the time during which the turbine rotational speed Nt is stabilized, becomes zero at the time t8, and then gradually increases with a negative value.

  Further, the ECU 100 continuously calculates the average rate of change of the differential rotation speed Nts4x. As shown in FIG. 4, the average rate of change gradually increases until slightly before the elapsed time t5 corresponding to the gradual increase of the differential rotation speed Nts4x, and gradually decreases at the time of the elapsed time t5. The characteristic curve is switched from a positive value to a negative value at an elapsed time t5 when a very short time has elapsed from the time, and then stable at a negative value.

  The ECU 100 always determines the time point of the elapsed time t6 when the average change rate of the differential rotation speed Nts4x switches from a positive value to a negative value in the downshift process, and the engagement side engagement element is engaged from the time point of the elapsed time t6. The gradual increase (sweep up) of the hydraulic pressure is started, and this gradual increase is performed from the elapsed time t6 to the elapsed time t10 where the turbine rotation speed is slightly longer than the elapsed time t9 that matches the synchronized rotation speed after shifting. Control is performed to increase the engagement hydraulic pressure so that the engagement-side engagement element is in a completely engaged state at time t10.

  In FIG. 4, for example, the sweep-up start time is not the time corresponding to the point A, but at the time when the time α has elapsed from the elapsed time t8 at which the turbine rotation speed is stabilized at a value lower than the synchronous rotation speed before shifting and starts to rise. Even if it is set, the elapsed time from the elapsed time t5 becomes longer, so that the shift response becomes slow. Even if the sweep-up start time is set to the time t7, the elapsed time is slightly shorter than the time t8, but the shift response becomes slow.

  On the other hand, in the present embodiment, the sweep-up start time is set as the time t6 when the average change rate of the differential rotation speed Nts4x is switched from a positive value to a negative value. Therefore, the time elapsed from the time t5 to the time t6 Can be suppressed for a very short time, so that the speed change response is improved.

  In addition, since the determination is not based on the turbine rotation speed, no erroneous determination is made with respect to a downhill or a disturbance from the road surface, pull-in G does not occur, and the engagement hydraulic pressure of the engagement side engagement element does not occur. Is gradually increased (sweep up) at an appropriate timing and time, and a shift shock can be effectively suppressed.

  The hydraulic control circuit 300 is controlled by the ECU 100 to release / engage the lock-up clutch 25 and release-engage the five friction engagement elements C1, C2, B1 to B3 of the automatic transmission 5. It is supposed to perform with the operation.

That is, the hydraulic control circuit 300, pumping oil from an oil pan (not shown) by the oil pump 7, the primary regulator valve by regulating the line pressure P _L corresponding to the throttle opening (not shown) the pressure oil delivered by the oil pump 7 The line pressure P _L or the further adjusted hydraulic pressure is supplied to and discharged from the torque converter 2 and the hydraulic servo of the lockup clutch 25.

  Further, the hydraulic control circuit 300 sends the pressure oil discharged from the lockup clutch 25 to the oil cooler for cooling, and further hydraulic servos for the first and second clutches C1 and C2 provided in the automatic transmission 5. The oil is supplied to and discharged from the hydraulic servos of the first, second, and third brakes B1 to B3, and the oil that lubricates the automatic transmission 5 is supplied to the inner surface of the case 6.

  The hydraulic control circuit 300 according to this embodiment includes an oil pump 7 that is rotated by a crankshaft of the engine 1 to generate hydraulic pressure, and a primary regulator that adjusts the hydraulic pressure generated by the oil pump 7 to a line pressure corresponding to the throttle opening. With respect to the valve, the manual valve (not shown in FIG. 1), the lock-up clutch 25, the first and second clutches C1 and C2, and the first, second and third brakes B1 to B3, A linear solenoid valve (not shown in FIG. 1) or the like for directly supplying a control pressure to a control pressure is provided to a lock-up clutch 25, a first clutch C1, a second clutch C1, and the like. The release-engagement operation of each of the C2, first, second, and third brakes B1 to B3 is executed.

  Below, hydraulic control at the time of downshifting from the second speed to the first speed will be described as an example of gripping change between the disengagement side engagement element and the engagement side engagement element at the time of downshifting.

  FIG. 5 shows a case where a downshift is performed from the second speed to the first speed. In a situation where the engine brake is further applied, the hydraulic control circuit portion 301 performs the first operation as shown in the operation table of FIG. A hydraulic control circuit portion 301 is shown that allows a change of grip between the brake B1 and the second brake B2.

  When the hydraulic control circuit portion 301 and the time chart of FIG. 4 are collated, the release hydraulic pressure in FIG. 4 indicates a change in hydraulic pressure of the hydraulic servo of the first brake B1, and the engagement side hydraulic pressure in FIG. The change of the hydraulic pressure of the hydraulic servo of the second brake B2 is shown.

  The hydraulic control circuit portion 301 urges the spool upward by a spring so as to link the hydraulic servo 302 of the first brake B1, the hydraulic servo 303 of the second brake B2, and the two hydraulic servos. The first to fourth control valves 304, 305, 306, and 307, which are lowered by hydraulic pressure, a linear solenoid valve 308, and a manual valve 309 are provided, and a pressure regulating solenoid valve (SLT) 310 and a solenoid are provided. A valve 311 is provided.

  The first control valve 304, the second control valve 305, the linear solenoid valve 308, and the pressure regulating solenoid valve 310 are input with the line pressure regulated by the primary regulator valve.

  Further, the pressure adjusting solenoid valve 310 adjusts the line pressure to the control pressure and outputs it to the solenoid valve 311. The solenoid valve 311 controls the signal pressure based on the control pressure of the fourth control valve 307. The output is selectively output to the port of the hydraulic chamber that pushes down the spool.

  The first control valve 304 is a valve having a spool that is lowered by a hydraulic thrust (hereinafter referred to as an operating pressure) that is urged upward by a spring and acts downward in the drawing.

  Based on a control signal from the ECU 100 (a control signal is output at time t1 in FIG. 4), the first control valve 304 is in the middle of the spool when the operating pressure is reduced and the spool is raised. The hydraulic chamber formed corresponding to the step portion is simultaneously connected to the port communicating with the hydraulic servo 302 and the port communicating with the second control valve 305, so that the line pressure is adjusted to the hydraulic servo 302. And the first brake B1 is brought into a completely engaged state and the spool of the second control valve 305 is pushed down.

Further, the first control valve 304 is configured to release the first brake B1.
Based on a control signal from the ECU 100, when the operating pressure rises and the spool descends, the hydraulic chamber is connected to the drain side and has a function of raising the spool of the second control valve 305.

  The second control valve 305 is a valve having a spool that is urged upward by a spring and that is raised (left half in FIG. 5) when the hydraulic pressure from the first control valve 304 decreases. That is, the spool of the second control valve 305 is raised when the engagement pressure of the first brake B1 is released.

  The second control valve 305 has a hydraulic chamber formed corresponding to a step part in the middle of the spool with respect to a port communicating with the manual valve 309 and a port communicating with the third control valve 306. When communicating, it has a function of outputting the line pressure output from the manual valve 309 to the third control valve 306. The second control valve 305 opens at time t2 in FIG.

  The third control valve 306 is a valve having a spool that is urged upward by a spring and lowered when the hydraulic pressure from the fourth control valve 307 is input to the upper hydraulic chamber.

  The third control valve 306 includes a port on the side where a hydraulic chamber formed corresponding to a step portion in the middle of the spool communicates with the second control valve 305 and a port on the side communicating with the fourth control valve 307. When the spool of the second control valve 305 is in the open state that communicates simultaneously, the line pressure output from the manual valve 309 is supplied to the fourth control valve 307 through the hydraulic chamber. It has the function to output to.

In the third control valve 306, the hydraulic pressure from the fourth control valve 307 that is input to the hydraulic chamber on the upper side of the spool is adjusted so that the line pressure becomes the control pressure P _SLU corresponding to the traveling state of the vehicle. Therefore, the degree of valve opening between the hydraulic chamber and the pair of ports in the middle of the spool can be changed according to the change in the control pressure _PSLU .

  The fourth control valve 307 is a valve having a spool that is biased upward by a spring and is lowered when a signal pressure from the solenoid valve 311 is input to the upper hydraulic chamber. The fourth control valve 307 has a function of simultaneously opening or closing the first and second hydraulic chambers in the middle of the spool.

  Specifically, the fourth control valve 307 includes a port on the side where the first hydraulic chamber formed in the middle of the spool and corresponding to the lower stepped portion communicates with the third control valve 306, and a hydraulic servo. A first valve mechanism portion that is in an open state communicating with a port on the side communicating with 303;

  The fourth control valve 307 has a second hydraulic chamber formed in the middle of the spool and corresponding to the upper stepped portion on the side where the third control valve 306 communicates with the spool pressing hydraulic chamber. A second valve mechanism portion that communicates with the port and the port that communicates with the linear solenoid valve 308 to open the valve.

  The fourth control valve 307 simultaneously closes the first and second valve mechanisms when the signal pressure from the solenoid valve 311 is reduced or cut in the upper hydraulic chamber. Opens when no signal pressure is input. The fourth control valve 307 simultaneously opens the first and second valve mechanisms at the elapsed time t2 in the timing chart of FIG.

  The pressure regulating solenoid valve (SLT) 310 regulates the solenoid modulator pressure in accordance with a control signal from the ECU 100 based on the accelerator opening detected by the accelerator opening sensor 204 and outputs the pressure to the solenoid valve 311.

  The solenoid valve 311 is a normally closed solenoid valve. The control pressure (throttle pressure) is input to the hydraulic valve chamber for pressing the spool of the fourth control valve 307 according to a control signal from the ECU 100 as a signal pressure. It is designed to output. The solenoid valve 311 reduces the signal pressure at the elapsed time t2 in the timing chart of FIG.

The linear solenoid valve 308 inputs a line pressure corresponding to the throttle opening, and based on a control signal from the ECU 100, the line pressure becomes a control pressure P _SLU corresponding to the traveling state of the vehicle. The pressure is adjusted and output to the second valve mechanism portion of the fourth control valve 307.

  Next, the hydraulic control circuit portion 301 having the above configuration will be described in relation to the timing chart of FIG.

  First, before there is a shift request output from the second speed to the first speed from the ECU 100, the line pressure from the first control valve 304 is input to the hydraulic servo 302, and the first brake B1 is in a fully engaged state.

  Further, the second control valve 305 is closed with respect to the third control valve 306 by the line pressure from the first control valve 304, and the hydraulic pressure of the hydraulic servo 303 is the release hydraulic pressure.

  The ECU 100 outputs a control signal so that the spool is lowered (right half in FIG. 5) to the first control valve 304 at the timing of the elapsed time t1. When the spool of the first control valve 304 is lowered, the line pressure input to the first control valve 304 is not transmitted to the hydraulic servo 302 and is released to the drain side. As a result, the release hydraulic pressure of the first brake B1 decreases.

  At this time, at the timing of the elapsed time t1, the ECU 100 controls the operating pressure of the first control valve 304 so as to open so as to decrease to the first fill pressure Pf, and then reaches the fully released state over the elapsed time t2 to t3. The operating pressure of the first control valve 304 is controlled so as to shift.

  When the release hydraulic pressure of the first brake B1 decreases, the spool of the second control valve 305 rises, and the line pressure is input to the third control valve 306 through the second control valve 305.

Further, the ECU 100 outputs a control signal to the solenoid valve 311 so as to decrease the signal pressure at the timing of the elapsed time t2. As a result, the fourth control is performed so that the solenoid valve 311 raises the spool of the fourth control valve 307 and the control pressure _PSLU from the linear solenoid valve 308 to the third control valve 306 can be transmitted. The first and second valve mechanisms of the valve 307 are simultaneously opened. That is, a shift output is made to the hydraulic control device 300.

  When the first and second valve mechanisms of the fourth control valve 307 are opened, the hydraulic pressure output from the third control valve 306 passes through the first valve mechanism of the fourth control valve 307 and is hydraulically Input to the servo 303.

However, the valve opening degree of the third control valve 306 is controlled by the control pressure _PSLU according to the traveling state of the vehicle output from the linear solenoid valve 308. The valve opening degree of the fourth control valve 307 is controlled by the signal pressure from the solenoid valve 311.

When the downshift is performed, the ECU 100 determines a point in time at which the sign of the average change rate of the differential rotational speed obtained by subtracting the turbine rotational speed from the synchronous rotational speed before shifting is switched from positive to negative at the timing of the elapsed time t6 in FIG. When it is determined that the sign has changed from positive to negative, the control pressure _PSLU is gradually increased (sweep up), so that the line pressure input from the manual valve 309 by the third control valve 306 is It outputs as a change of the engagement hydraulic pressure of FIG. 4, and performs sweep-up control. At this time, the opening degree of the fourth control valve 307 may be adjusted and the sweep-up control may be executed in cooperation with the third control valve 306.

Then, at the elapsed time t10 in FIG. 4, the ECU 100 causes the linear solenoid valve 308 to increase the control pressure _PSLU at a stroke, the third control valve 306 is fully opened, and the second brake B2 is fully engaged. The engagement hydraulic pressure in FIG. 4 is controlled so as to be in the state. At this time, the operation pressures of both the control pressure _PSLU and the signal pressure from the solenoid valve 311 are increased at once, so that the third control valve 306 and the fourth control valve 307 are fully opened. Good.

  Next, processing executed by the ECU 100 will be briefly described with reference to FIG. The ECU 100 repeatedly executes the process described below at predetermined time intervals.

  First, when there is a downshift request, the ECU 100 calculates a differential rotational speed obtained by subtracting the turbine rotational speed from the pre-shift periodic rotational speed (step S1). Next, the ECU 100 calculates the average change rate of the differential rotation speed calculated in step S1 (step S2).

  Next, ECU 100 determines whether the sign of the average change rate calculated in step S2 has been switched from positive to negative as indicated by point A in FIG. 4 (step S3). When ECU 100 determines that the sign of the average rate of change has been switched from positive to negative as indicated by point A in FIG. 4, it starts the sweep-up control (step S4), and the sign of the average rate of change is positive. If it is determined not to switch to negative, the process ends.

  According to the above-described embodiment, when the automatic transmission is downshifted, even when the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface, the turbine rotational speed Can be accurately detected, i.e., the timing at which the engagement pressure of the engagement-side engagement element is gradually increased, so that both shift response and shift shock suppression can be achieved.

  According to the above-described embodiment, the sweep-up control when the shift lever is operated to downshift in the manual shift mode in which the M position is selected has been described. However, the present invention is not limited to this.

  Specifically, even when the ECU 100 executes a downshift based on a shift diagram determined based on the vehicle speed and the accelerator opening stored in advance in the ROM in the automatic shift mode in which the D position is selected, Sweep-up control may be performed by the time chart shown in FIG. 4 and the hydraulic control circuit portion 301 shown in FIG.

  According to the above-described embodiment, the downshift from the 2nd speed to the 1st speed has been described, but the downshift other than the downshift from the 2nd speed to the 1st speed is similar to the hydraulic control circuit portion 301 shown in FIG. By providing this hydraulic control circuit portion, sweep-up control can be performed.

  According to the above-described embodiment, the case where the present invention is applied to a drive train on which a so-called automatic transmission is mounted has been described. And an automatic transmission that is connected to the electric motor so as to be able to transmit power and transmits the power from the driving power source for driving to the driving wheel side, and only the electric motor is driven for driving with the clutch released. The present invention can be applied even to a hybrid vehicle capable of traveling by a motor traveling as a source.

  As described above, in the vehicle control apparatus according to the present invention, when the automatic transmission is downshifted, the actual input rotational speed of the automatic transmission increases due to, for example, a downhill or a disturbance from the road surface. Even in such a case, it is possible to accurately detect the timing at which the turbine rotational speed is increased, that is, the timing at which the engagement pressure of the friction engagement element is gradually increased, and it is possible to achieve both shift response and shift shock suppression. It is useful for all control devices for vehicles equipped with an internal combustion engine and an automatic transmission.

1 engine (internal combustion engine)
6 Automatic transmission C1 First clutch (friction engagement element)
C2 Second clutch (friction engagement element)
B1 First brake (friction engagement element)
B2 Second brake (friction engagement element)
B3 Third brake (friction engagement element)
100 ECU
300 Hydraulic control circuit

Claims (1)

In a control apparatus for a vehicle equipped with an internal combustion engine and an automatic transmission that changes the power transmission path by shifting the rotational power output from the internal combustion engine by gripping a plurality of friction engagement elements,
In the downshift process of the automatic transmission, on the condition that the sign of the average change rate of the differential rotational speed obtained by subtracting the turbine rotational speed from the synchronous rotational speed before shifting is changed from positive to negative, the frictional coefficient on the engagement side is changed. A control apparatus for a vehicle, which starts sweeping up engagement hydraulic pressure of a joint element.

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