JP2018013232A - Control device of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a vehicle which can suppress an engine stall at changeover to a traveling position from a non-traveling position, in the vehicle having an automatic transmission which performs a gear change by making a plurality of engagement elements selectively engaged with one another.SOLUTION: Changeover to a traveling position from a non-traveling position is performed at a low speed normally, and a rotational speed sensor used for synchronous completion determination is liable to generate a measurement error as a vehicle speed is low. When an input shaft rotational speed at which the engagement of an engagement-side friction engagement device is completed after the establishment of a gear stage is not higher than a target rotational speed which is obtained by adding a prescribed value A to a target idling rotational speed, the engagement hydraulic pressure of the engagement-side friction engagement device is raised when a difference between an engine rotation number and an input shaft rotation number reaches a prescribed value B or larger after the lapse of a prescribed time.SELECTED DRAWING: Figure 6

Description

  The present invention relates to control of a friction engagement element of a stepped automatic transmission for a vehicle that performs a shift by a combination of a plurality of friction engagement elements.

  In a vehicle control device including a stepped automatic transmission that performs a multiple-stage shift by a combination of an engine, a fluid transmission device, and engagement operations of a plurality of friction engagement elements, an input shaft rotation speed is predetermined during shift control. The synchronization determination of the friction engagement element is performed by continuing within the range for a predetermined time or more, and the engagement hydraulic pressure supplied to the friction engagement element whose engagement is controlled, that is, the engagement side friction engagement element is increased. Thus, there is known a control device for a stepped automatic transmission for a vehicle in which the engagement side frictional engagement element is completely engaged. For example, this is the control device for a stepped automatic transmission for a vehicle described in Patent Document 1. In the control apparatus for a stepped automatic transmission for a vehicle disclosed in Patent Document 1, synchronization of the engagement-side frictional engagement element is completed when the input shaft rotation speed continues for a predetermined time or more during shift control. And determining the engagement timing of the engagement side frictional engagement element accurately by increasing the engagement hydraulic pressure based on the synchronization completion determination and performing the full engagement of the engagement side frictional engagement element. Therefore, it is possible to suppress the occurrence of shock at the time of shifting and to improve the responsiveness.

JP 2004-257460 A

  By the way, in a vehicle having a shift position selection device, when the shift position is switched from the non-travel position to the travel position, the synchronization of the engagement-side frictional engagement element that completes the establishment of the shift destination shift stage is determined. The input shaft rotational speed of the input shaft that transmits the driving force to the stepped automatic transmission via the fluid transmission device remains within a predetermined range including the synchronized rotational speed after the shift during the shift for a predetermined time or longer. If the synchronization is determined to be complete based on the fact that the synchronization is completed, control is performed to increase the engagement hydraulic pressure supplied to the engagement-side frictional engagement element. Further, when switching from the non-traveling position to the traveling position, traveling in which the vehicle speed is decreasing, that is, the output shaft rotation speed is often decreased. Therefore, the input shaft rotational speed after engagement of the friction engagement element calculated by multiplying the output shaft rotational speed by the gear ratio after the shift is also low, and per rotation with the rotation of the input shaft. By reading a predetermined number of outputs, the measurement accuracy of the rotational speed sensor that determines the rotational speed of the input shaft also decreases. When the completion of synchronization of the engagement side frictional engagement element is determined in the state where the error of the input shaft rotation sensor has occurred, and the engagement hydraulic pressure is increased based on the synchronization completion determination, the driver feels uncomfortable due to the shift shock and the engine stall That is, there is a possibility that the engine stop unintended by the driver occurs.

  The present invention has been made against the background of the above circumstances, and the purpose of the present invention is also in switching from a non-traveling position to a traveling position of a shift position in which an error of the input shaft rotation sensor is likely to increase. It is an object of the present invention to provide a vehicle control device that can suppress a driver's uncomfortable feeling due to a shift shock and an engine stall, that is, an engine stop that is not intended by the driver.

  The gist of the first invention is that: (a) a stepped automatic transmission that performs a multi-stage shift by a combination of an engine, a fluid transmission device, and engagement operations of a plurality of friction engagement elements; and shift position selection And (b) the completion of synchronization of the engagement-side frictional engagement element in the clutch-to-clutch shift for completing the establishment of the shift destination, and the driving force of the engine as the fluid transmission. Based on the fact that the input shaft rotational speed of the input shaft that is transmitted to the stepped automatic transmission via the device continues in a predetermined range including the synchronous rotational speed after establishment of the shift stage for a predetermined time or more. And when the completion of synchronization is determined, the vehicle control device increases the engagement hydraulic pressure supplied to the engagement side frictional engagement element, and is selected by the shift position selection device. When the synchronous rotational speed when the shift position is switched from the non-traveling position to the traveling position is lower than a value obtained by adding a predetermined value to the target idle rotational speed of the engine, the engine speed is further determined as a condition for determining the completion of synchronization. In addition to the fact that the input shaft rotational speed is lower than the predetermined value by a predetermined value or more, the synchronization completion determination of the engagement side frictional engagement element is performed.

  According to this configuration, a vehicle including an engine, a fluid transmission device, a stepped automatic transmission that performs a multi-stage shift by a combination of engagement operations of a plurality of friction engagement elements, and a shift position selection device. In the control device, the completion of synchronization of the engagement side frictional engagement element in the clutch-to-clutch shift for completing the establishment of the shift destination shift stage, the stepped automatic transmission using the driving force of the engine via the fluid transmission device The input shaft rotation speed of the input shaft to be transmitted to the vehicle is determined based on the fact that the input shaft rotation speed remains within a predetermined range including the synchronous rotation speed after the shift stage is established for a predetermined time or more, and the synchronization completion is determined In this case, the engagement hydraulic pressure supplied to the engagement side frictional engagement element is increased. In addition to this, the synchronous rotational speed when the shift position selected by the shift position selection device is switched from the non-travel position to the travel position is lower than a value obtained by adding a predetermined value to the target idle speed of the engine. In this case, the synchronization completion determination of the engagement-side frictional engagement element is performed by further adding that the input shaft rotation speed is lower than the engine rotation speed by a predetermined value or more as the determination condition for the synchronization completion. For this reason, when the synchronous rotational speed when the shift position selected by the operation of the shift position selecting device is switched from the non-traveling position to the traveling position exceeds a value obtained by adding a predetermined value to the idle rotational speed of the engine. Since the engine stall does not occur even if errors occur in the measured values of the input shaft rotation speed, the output shaft rotation speed, and the engine rotation speed, the engagement is immediately supplied to the engagement side frictional engagement element. The combined hydraulic pressure can be increased, and the delay in the synchronization completion determination is prevented. Further, when the engine stall may occur due to the synchronous rotation speed being lower than a value obtained by adding a predetermined value to the engine idle rotation speed, the input shaft rotation speed is lower than the engine rotation speed by a predetermined value or more. By adding this to the determination condition, the occurrence of engine stall can be suppressed.

It is a figure explaining the principal part of the control function and various control systems for various controls in vehicles to which the present invention is applied. It is a figure explaining the schematic structure of the vehicle to which the present invention is applied. It is an engagement operation | movement table | surface which shows each operation state of each friction engagement element in each gear stage. It is a figure which shows an example of the operation position of a shift position selection apparatus. It is a circuit diagram which shows an example of the principal part of the hydraulic control circuit regarding the linear solenoid valve etc. which control the action | operation of each hydraulic actuator of a friction engagement element. 2 is a flowchart illustrating a basic operation of a friction engagement element in switching from a non-traveling position to a traveling position, which is a main part of the control operation of the electronic control device of FIG. 1. FIG. 7 is an example of a time chart showing an engine rotation speed, an input shaft rotation speed, and a vehicle weight acceleration generated in the traveling direction of the vehicle when the control operation of FIG. 6 is not performed. It is an example of the time chart at the time of performing the control action shown to the flowchart of FIG. It is an example of the time chart at the time of performing the control action shown to the flowchart of FIG. 6, and is a time chart when the input shaft rotational speed after engagement of a friction engagement element is larger than idle rotational speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

  FIG. 1 is a diagram illustrating a schematic configuration of a vehicle 10 to which the present invention is applied, and a diagram illustrating a main part of a control system for various controls in the vehicle 10. In FIG. 1, a vehicle 10 includes an engine 12, drive wheels 14, a vehicle power transmission device 16 (hereinafter referred to as a power transmission device 16) provided in a power transmission path between the engine 12 and the drive wheels 14. It has. The power transmission device 16 includes a torque converter 20 and a stepped automatic transmission 22 (hereinafter referred to as automatic transmission) functioning as a fluid transmission device 20 disposed in a case 18 (see FIG. 2) as a non-rotating member attached to a vehicle body. A differential gear device 26 in which a transmission output gear 24, which is an output rotating member of the automatic transmission 22, is connected to a ring gear 26a, a pair of axles 28 connected to the differential gear device 26, and the like. It has. In the power transmission device 16, the power output from the engine 12 is transmitted to the drive wheels 14 via the torque converter 20, the automatic transmission 22, the differential gear device 26, the axle 28 and the like in order. The torque converter 20 is provided in a power transmission path between the automatic transmission 22 and the engine 12.

  The engine 12 is a power source of the vehicle 10 and is, for example, an internal combustion engine such as a gasoline engine or a diesel engine.

  FIG. 2 is a skeleton diagram illustrating an example of the torque converter 20 and the automatic transmission 22. The torque converter 20, the automatic transmission 22, and the like are configured substantially symmetrically with respect to the axis RC of the transmission input shaft 30 that is an input rotation member of the automatic transmission 22, and in FIG. The lower half of RC is omitted.

  The torque converter 20 is connected to the crankshaft 12a of the engine 12 so as to be able to transmit power, and transmits power to a pump impeller (input member) 20p arranged to rotate around an axis RC and a transmission input shaft 30. A turbine impeller (output member) 20t that can be connected to each other and a lockup clutch 32 that directly connects the pump impeller 20p and the turbine impeller 20t are provided. The power transmission device 16 is provided with a mechanical oil pump 34 connected to the pump impeller 20p so as to be able to transmit power. The oil pump 34 is rotationally driven by the engine 12 to control the shift of the automatic transmission 22, engage the lockup clutch 32, and supply lubricating oil to each part of the power transmission path of the power transmission device 16. Generate hydraulic pressure to discharge (discharge).

  The automatic transmission 22 constitutes a part of a power transmission path from the engine 12 to the driving wheel 14 and functions as a friction engagement element (first clutch C1 to fourth clutch C4, first clutch 1). Functions as a stepped automatic transmission in which a plurality of gear stages (shift speeds) having different gear ratios (speed ratios) are formed by selectively engaging either the brake B1 or the second brake B2) This is a planetary gear type multi-stage transmission. For example, it is a stepped transmission that performs a so-called clutch-to-clutch shift often used in vehicles. The automatic transmission 22 includes a double pinion type first planetary gear unit 42, a single pinion type second planetary gear unit 44 and a double pinion type third planetary gear unit 46 configured in Ravigneaux on a coaxial line. (On the shaft center RC), the rotation of the transmission input shaft 30 is shifted and output from the transmission output gear 24.

  The first planetary gear unit 42 includes a first sun gear S1 that is an external gear, a first ring gear R1 that is an internal gear disposed concentrically with the first sun gear S1, a first sun gear S1, and a first ring gear R1. And a first carrier CA1 that supports the first pinion gear P1 so as to be able to rotate and revolve.

  The second planetary gear unit 44 includes a second sun gear S2 that is an external gear, a second ring gear R2 that is an internal gear disposed concentrically with the second sun gear S2, a second sun gear S2, and a second ring gear R2. And a second carrier CA2 that supports the second pinion gear P2 so as to be capable of rotating and revolving.

  The third planetary gear unit 46 includes a third sun gear S3 that is an external gear, a third ring gear R3 that is an internal gear disposed concentrically with the third sun gear S3, and the third sun gear S3 and the third ring gear. It has a third pinion gear P3 made up of a pair of gears that meshes with R3, and a third carrier CA3 that supports the third pinion gear P3 so that it can rotate and revolve.

  The first clutch C1, the second clutch C2, the third clutch C3, the fourth clutch C4, and the first brake B1 and the second brake B2 (hereinafter simply referred to as a friction engagement device unless otherwise distinguished) are hydraulic actuators. Wet multi-plate type clutches and brakes pressed by a band brake, band brakes tightened by a hydraulic actuator, and the like.

  By controlling the engagement and disengagement of these friction engagement devices, as shown in the engagement operation table of FIG. 3, each of the eight forward speeds and the reverse one speed is determined according to the accelerator operation of the driver, the vehicle speed V, etc. A gear stage is formed. In FIG. 3, “1st”-“8th” means the first gear-eighth gear as the forward gear, and “Rev” means the reverse gear as the reverse gear. The gear ratio γ (= transmission input shaft rotational speed Nin / transmission output gear rotational speed Nout) of the automatic transmission 22 corresponding to the first planetary gear device 42, the second planetary gear device 44, and the third planetary gear. Each gear ratio of the device 46 (= number of teeth of the sun gear / number of teeth of the ring gear) is appropriately determined.

  FIG. 4 is a diagram illustrating an example of the operation position Psh of the shift lever 82. As shown in FIG. 4, the shift lever 82 is manually operated to the operation positions “P”, “R”, “N”, “D”, or “M”. The operation position “P” selects the parking position (P position) of the automatic transmission 22, and the automatic transmission 22 is in a neutral state (neutral state) in which the power transmission path is interrupted (that is, the engine is released by releasing the friction engagement device). Parking operation position P (hereinafter referred to as a P operation position) for mechanically preventing the transmission output gear 24 from rotating and setting the power transmission path between the drive wheel 14 and the drive wheel 14 to a neutral state in which power transmission is impossible. It is. The operation position “R” is a reverse travel operation position R (hereinafter referred to as “R operation position”) for selecting the reverse travel position (R position) of the automatic transmission 22 and traveling backward. The R operation position is a travel operation position that enables reverse travel using the reverse gear of the automatic transmission 22. The operation position “N” is a neutral operation position N (hereinafter referred to as N operation position) for selecting the neutral position (N position) of the automatic transmission 22 and setting the automatic transmission 22 in the neutral state. The P operation position and the N operation position are non-travel operation positions that disable travel by the power of the engine 12, respectively. The operation position “D” selects a forward travel position (D position) of the automatic transmission 22, and a forward travel operation position D (hereinafter referred to as “D operation position”) for traveling forward (that is, the automatic transmission 22 of the automatic transmission 22. (D operation position in which the power transmission path between the engine 12 and the drive wheels 14 is in a power transmission enabled state in which a power transmission path for forward traveling is formed) by engagement of the friction engagement device forming the forward gear. is there. The D operation position is automatically set using all the forward gears of the first speed gear stage “1st” to the eighth speed gear stage “8th” within a shift range (D range) that allows the automatic transmission 22 to shift. This is a travel operation position that enables forward travel by executing shift control. The operation position “M” is a manual shift operation position M (hereinafter referred to as “M operation position”) for switching the gear position of the automatic transmission 22. The M operation position is a traveling operation position that enables manual gear shifting, in which the gear position of the automatic transmission 22 is switched by an operation by a driver. In this M operation position, an upshift operation position “+” for shifting the gear stage up every time the shift lever 82 is operated, and a down shift for shifting the gear stage down every time the shift lever 82 is operated. A shift operation position “−” is provided. Thus, the shift lever 82 functions as a gear stage switching operation member that receives a gear stage switching request of the automatic transmission 22 by being manually operated. When the operation position Psh is in the D operation position, an automatic transmission mode (hereinafter referred to as D mode) for automatically shifting the automatic transmission 22 according to a known shift map is established, and when the operation position Psh is in the M operation position, A manual shift mode (hereinafter, referred to as a manual mode or an M mode) that can shift the automatic transmission 22 by a shift operation by the driver is established.

  FIG. 5 is a circuit diagram showing a main part of the hydraulic control circuit 50 relating to the solenoid valves SL1-SL6 and the like that control the operation of the hydraulic actuators ACT1-ACT6 of the friction engagement device. In FIG. 5, the hydraulic control circuit 50 includes a hydraulic pressure supply device 52 and solenoid valves SL1-SL6.

  The hydraulic pressure supply device 52 adjusts the line hydraulic pressure PL using the hydraulic pressure generated by the oil pump 34 as a source pressure, and supplies the signal pressure Pslt to the primary regulator valve 54 so that the line hydraulic pressure PL is regulated. A solenoid valve SLT, a modulator valve 56 that regulates the modulator hydraulic pressure PM to a constant value using the line hydraulic pressure PL as a source pressure, and a manual valve 58 that mechanically switches the oil path in conjunction with the switching operation of the shift lever 82 are provided. ing. When the shift lever 82 is in the D operation position or the M operation position, the manual valve 58 outputs the input line oil pressure PL as the forward oil pressure (D range pressure, drive oil pressure) PD, and the shift lever 82 is set to the R operation position. In some cases, the input line hydraulic pressure PL is output as a reverse hydraulic pressure (R range pressure, reverse hydraulic pressure) PR. Further, when the shift lever 82 is in the N operation position or the P operation position, the manual valve 58 cuts off the hydraulic pressure output and guides the drive hydraulic pressure PD and the reverse hydraulic pressure PR to the discharge side. As described above, the hydraulic pressure supply device 52 outputs the line hydraulic pressure PL, the modulator hydraulic pressure PM, the drive hydraulic pressure PD, and the reverse hydraulic pressure PR.

  The hydraulic pressures Pc1, Pc2, and Pc4 adjusted by the solenoid valves SL1, SL2, and SL4, respectively, are supplied to the hydraulic actuators ACT1, ACT2, and ACT4 of the clutches C1, C2, and C4 using the drive hydraulic pressure PD as a source pressure. In addition, hydraulic pressures Pc3, Pb1, and Pb2 that are regulated by solenoid valves SL3, SL5, and SL6, respectively, are supplied to the hydraulic actuators ACT3, ACT5, and ACT6 of the clutch C3 and the brakes B1 and B2 using the line hydraulic pressure PL as a source pressure. The The solenoid valves SL1 to SL6 basically have the same configuration, and are individually excited, de-energized, and current controlled by an electronic control unit 40 corresponding to the control unit 40, and each hydraulic pressure Pc1, Pc2, Pc3 is controlled. , Pc4, Pb1, and Pb2 are independently regulated. Note that the hydraulic control circuit 50 includes a shuttle valve 59, and either the hydraulic pressure Pb2 or the reverse hydraulic pressure PR is supplied to the hydraulic actuator ACT6 of the brake B2 via the shuttle valve 59. Thus, the hydraulic control circuit 50 supplies hydraulic pressure to the friction engagement device based on the hydraulic control command signal Sat (hydraulic command value) output from the electronic control device 40. The manual valve 58 outputs a drive hydraulic pressure PD and a reverse hydraulic pressure PR, which are the original pressures of the hydraulic pressure supplied to the friction engagement device.

  Returning to FIG. 1, the vehicle 10 performs engagement hydraulic pressure control for controlling the engagement pressure of the friction engagement device when the shift lever 82 is manually operated to the N operation position or the P operation position which is a non-travel position, for example. An electronic control unit 40 that is executed via a hydraulic control circuit 50 is provided. FIG. 1 is a diagram showing an input / output system of the electronic control device 40, and is a functional block for explaining a main part of a control function by the electronic control device 40. The electronic control unit 40 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Each control of the vehicle 10 is executed by performing signal processing.

  Various input signals detected by various sensors provided in the vehicle 10 are supplied to the electronic control unit 40. For example, the engine rotational speed Ne (rpm) detected by the engine rotational speed sensor 70, the input shaft rotational speed Nin (rpm) also called the turbine rotational speed Nt detected by the input shaft rotational speed sensor 72, and the output shaft rotational speed. The transmission output gear rotation speed corresponding to the vehicle speed V detected by the sensor 74, that is, the output shaft rotation speed Nout (rpm), the accelerator opening θacc (%) detected by the accelerator opening sensor 76, and the brake switch 78 are detected. A brake signal Bon, a signal indicating an operation position Psh indicating the operation of the shift lever 82 detected by the shift position sensor 80, and the like are input to the electronic control unit 40. For rotational speed sensors such as the engine rotational speed sensor 70, the input shaft rotational speed sensor 72, and the output shaft rotational speed sensor 74, gear-like protrusions formed on the gear rotor fitted into the rotating member are MR sensors (magnetic resistance sensors) or the like. A method for detecting the rotational speed by detecting as a pulse by the method, or a method for detecting the rotational speed by detecting a magnetic reversal between the N pole and the S pole formed on the surface of the magnetic rotor as a pulse by a Hall element or the like. Etc. are used. Further, the electronic control unit 40 gives instructions such as a shift command pressure Sat for hydraulic control related to the shift of the automatic transmission 22, a throttle (not shown) of the engine 12, ignition timing of the ignition coil, fuel injection amount, valve timing, and the like. A signal Se, a command pressure Slu for switching control of the operation state of the lockup clutch 32, and the like are output.

  The electronic control device 40 shown in FIG. 1 includes, as essential parts of its control function, a travel position switching determination means 90, a post-shift gear position determination means 92, a synchronous rotation speed determination means 94, a synchronization time determination means 96, Rotational speed difference determining means 98, synchronous rotation determining means 100, and engagement hydraulic pressure control means 102 are provided.

  The travel position switching determining means 90 enables a shift position, a P operation position, a neutral operation position, and an N operation position, which is a neutral operation position, to a travel position, that is, a D operation position, which is a forward travel position, and manual shifting. It is determined whether or not switching has been made to either the M operation position that is the travel operation position or the R operation position that is the reverse travel position. Hereinafter, a case where switching from the N operation position that is the non-travel position to the D operation position that is the travel position will be described. When switching from the N operation position to the D operation position is determined, the post-shift gear position determination unit 92 continues the control and outputs the output when both the accelerator opening θacc and the brake signal Bon are substantially zero. A gear stage established based on the shaft rotation speed Nout, that is, the vehicle speed V is determined based on a shift map stored in advance. When the established gear stage is determined, the synchronous rotational speed determining means 94 multiplies the gear ratio (transmission ratio) γ at the established gear stage by the output shaft rotational speed Nout to obtain the synchronous rotational speed Nsin of the input shaft after the shift. At the same time, it is determined whether or not the calculated synchronous rotational speed Nsin is equal to or lower than a predetermined target engine rotational speed Net, that is, a rotational speed obtained by adding a predetermined value A to the target idle rotational speed Nidle. The target idle speed Nidle is an engine speed Ne set in advance so that the rotation is maintained when the accelerator opening degree θacc is substantially zero at the N operation position, and the predetermined value A is used for synchronization determination. Even if the measurement error of the output shaft rotational speed Nout and the input shaft rotational speed Nin occurs, the value is experimentally obtained and set in advance so that the engine stall, that is, the unintended stop of the engine 12 does not occur. The above determination is often made in a region where the low vehicle speed, that is, the output shaft rotational speed Nout is low, and the target idle rotational speed Nidle is also set to a relatively low rotational speed, for example, about 700 to 800 rpm in order to reduce fuel consumption. Has been. Rotational speed sensors such as the engine rotational speed sensor 70, the input shaft rotational speed sensor 72, and the output shaft rotational speed sensor 74 detect the number of pulses generated by the rotation of the crankshaft 12a, the input shaft 30, and the output shaft 24. The engine rotational speed Ne, the input shaft rotational speed Nin, and the output shaft rotational speed Nout are detected, and the measurement error increases as the low rotational speed, that is, the number of pulses per unit time decreases, and the target engine rotational speed Net is set. It is necessary to add the predetermined value A to the target idle speed Nidle.

  The synchronous rotational speed determination means 94 is simply not required for one friction engagement apparatus, that is, engagement control, of the two friction engagement apparatuses forming the gear stage after the shift via the engagement hydraulic pressure control means 102. An engagement-side friction engagement device Cc that functions as an engagement-side friction engagement element Cc, which is another friction engagement device than the friction engagement device that increases the hydraulic command pressure and quickly increases the engagement hydraulic pressure. Is controlled based on a predetermined pre-stored rising speed. In the N operation position, all the friction engagement devices are in a released state, and which of the two friction engagement devices constituting the gear stage after the shift is to be quickly raised to the engagement hydraulic pressure is determined. It is preset for each gear stage. Further, when the synchronous rotational speed determining means 94 determines that the calculated synchronous rotational speed Nsin is equal to or lower than the target engine rotational speed Net, that is, the rotational speed obtained by adding the predetermined value A to the target idle rotational speed Nidle, the synchronous rotational speed determining means 96 and the synchronous rotational speed determining means 96 A signal is sent to the determining means 100 that the calculated synchronous rotational speed Nsin is equal to or lower than the target engine rotational speed Net. The synchronization time determination unit 96 determines whether the input shaft rotation speed Nin is maintained for a predetermined time ta (sec) within a synchronization rotation speed area Nsina, which is a rotation speed area including a predetermined synchronization rotation speed Nsin. Determine whether engagement has been reached. The synchronous rotational speed region Nsina only needs to be a rotational speed region including the synchronous rotational speed Nsin, and the synchronous rotational speed Nsin does not have to be a median value. When the synchronization time determination means 96 determines that the predetermined engagement has been reached, the rotational speed difference determination means 98 determines that the difference between the engine rotational speed Ne and the input shaft rotational speed Nin, also referred to as the turbine rotational speed Nt (rpm), is predetermined. It is determined whether or not the value is greater than or equal to B. The predetermined value B is a value experimentally determined in advance so that engine stall does not occur even when the engagement side frictional engagement device Cc is completely engaged. This determination is affirmative, that is, the engagement-side friction engagement device Cc reaches a predetermined engagement, and the difference between the engine rotation speed Ne and the input shaft rotation speed Nin further advances the engagement, thereby engaging the engagement-side friction engagement. By reaching a predetermined value B or more at which engine stall does not occur even when the combined device Cc is completely engaged, the synchronous rotation determining means 100 determines completion of synchronous rotation, and the engagement hydraulic pressure control means 102 is engaged. The clutch-to-clutch shift is completed by increasing the pressure to the final hydraulic pressure command value at the time of engagement, which is called combined pressure increase.

  When the synchronous rotational speed determining means 94 determines that the calculated synchronous rotational speed Nsin exceeds the target engine speed Net, the two relations for forming the gear stage after the shift via the engagement hydraulic pressure control means 102 are determined. After the quick fill, the hydraulic command pressure of one of the engagement elements is quickly increased to the engagement hydraulic pressure, and the engagement hydraulic pressure of the other engagement side frictional engagement device Cc is stored in a predetermined hydraulic pressure. Control based on the rising speed of the indicated pressure. Further, the synchronous rotational speed determining means 94 sends a signal to the synchronous time determining means 96 and the synchronous rotational determining means 100 that the calculated synchronous rotational speed Nsin exceeds the target engine rotational speed Net. The synchronization time determination unit 96 determines whether or not the input shaft rotation speed Nin is maintained at a rotation speed within a synchronization rotation speed area Nsina that is a rotation speed area including a predetermined synchronization rotation speed Nsin for a predetermined time ta (sec). To determine whether a predetermined engagement has been reached. Since this determination is affirmative, that is, the engagement-side frictional engagement device Cc has reached a predetermined engagement, the synchronous revision determination means 100 determines the completion of synchronous rotation, and the engagement hydraulic pressure control means 102 The pressure is increased to the final hydraulic pressure command value at the time of engagement, which is called engagement pressure increase. When the synchronous rotational speed Nsin exceeds the target engine rotational speed Net, the synchronous rotational speed Nsin is higher than the target engine rotational speed Net even if the engagement pressure is increased and the engagement element is completely engaged, that is, the input shaft If the engagement element is completely engaged even when the error of the rotational speed sensor 72 is taken into account, the engine rotational speed Ne is increased higher than the target idle rotational speed Nidle, and an unexpected stop of the engine 12, that is, engine stall is caused. Does not occur.

  FIG. 6 is a flowchart for explaining the control operation when the electronic control device 40 is switched to the non-travel position travel position by operating the shift lever 82, that is, the control operation.

  In FIG. 6, whether or not switching from the non-traveling position, that is, the N operating position to the D operating position, which is the traveling position, is performed in step S10 corresponding to the function of the traveling position switching determination means 90 (hereinafter, step is omitted). Is determined. If this determination is negative, this routine is terminated. If the determination in S10 is affirmative, in S20 corresponding to the functions of the post-shift gear determining means 92 and the shift rotation speed determining means 94, the gear stage established after switching from the N operation position to the D operation position is determined. At the same time, the synchronous rotational speed Nsin of the transmission input shaft 30 after the shift is calculated by multiplying the output shaft rotational speed Nout by the gear ratio γ at the established gear stage. In S30 corresponding to the function of the transmission rotational speed determination means 94, it is determined whether or not the calculated synchronous rotational speed Nsin is equal to or lower than a preset target engine rotational speed Net. If this determination is affirmative, in S40 corresponding to the function of the engagement hydraulic pressure control means 102, the hydraulic pressure is determined based on the command pressure to the engagement side frictional engagement device Cc that is preset for each established gear stage. And the engagement hydraulic pressure of the other engagement element is increased immediately after the quick fill. In S60 corresponding to the function of the synchronization time determination means 96, it is determined whether or not the input shaft rotation speed Nin is maintained in the synchronization rotation speed region Nsina for a predetermined time ta. After the predetermined time ta has elapsed, that is, when the determination in S60 is affirmative, the difference between the engine rotation speed Ne and the input shaft rotation speed Nin is equal to or greater than a predetermined value B in S80 corresponding to the function of the rotation speed difference determination means 98. It is determined whether or not. When the difference between the engine rotation speed Ne and the input shaft rotation speed Nin reaches a predetermined value B or more, in S90 corresponding to the functions of the synchronous rotation determination unit 100 and the engagement hydraulic pressure control unit 102, the completion of the synchronous rotation is determined. In S90, which corresponds to the function of the engagement hydraulic pressure control means 102, a pressure increase to the final hydraulic pressure at the time of engagement, called engagement pressure increase, is performed.

  In S30 corresponding to the function of the transmission rotational speed determination means 94, it is determined whether or not the calculated synchronous rotational speed Nsin is equal to or lower than a rotational speed obtained by adding a predetermined value A to a preset target idle rotational speed Nidle. If this determination is negative, in S40 corresponding to the function of the engagement hydraulic pressure control means 102, based on the command pressure to the engagement side frictional engagement device Cc preset for each established gear stage. Thus, the hydraulic pressure is increased, and the other engaging element is increased immediately after the quick fill. In S70 corresponding to the function of the synchronization time determination means 96, it is determined whether or not the input shaft rotation speed Nin is maintained in the synchronization rotation speed region Nsina for a predetermined time ta. If this determination is affirmative, in S90 corresponding to the functions of the synchronous rotation determination means 100 and the engagement hydraulic pressure control means 102, the completion of the synchronous rotation is determined and corresponds to the function of the engagement hydraulic pressure control means 102. In S90, the pressure is increased to the final hydraulic pressure at the time of engagement, which is called engagement pressure increase.

  FIG. 7 shows a time chart when the engagement hydraulic pressure of the engagement side frictional engagement device Cc in this embodiment is not controlled. FIG. 7 shows the change over time of the engine rotational speed Ne and the input shaft rotational speed Nin, the command pressure to the clutch, and the weight acceleration G in the vehicle longitudinal direction when switching from the N position to the D position is performed. Is shown. At time t1, switching from the N position to the D position is performed. The engine rotation speed Ne is slightly higher than the target idle rotation speed Nidle, and the input shaft rotation speed Nin indicates a rotation speed slightly lower than the target idle rotation speed Nidle. The clutch oil pressure command, that is, the clutch oil pressure command pressure Pc is increased from substantially zero to the quick fill command pressure P3, and the vehicle front-rear G, which is the weight acceleration G in the vehicle front-rear direction, indicates substantially zero, that is, coasting. At time t2, the inertia phase of the engagement side frictional engagement device Cc starts, that is, the engagement starts, the engine rotational speed Ne and the input shaft rotational speed Nin start to decrease slightly, and the weight acceleration G also increases slightly. doing. The clutch command hydraulic pressure Pc indicates P1. At the time t3, the engagement of the engagement side frictional engagement device Cc is determined, and the hydraulic pressure instruction value Pc to the engagement side frictional engagement device Cc is the final instruction at the time of engagement called the engagement pressure increase from the instruction pressure P2. The pressure is increased to the pressure P4. At this time, the engine 12 is suddenly engaged with the engagement-side frictional engagement device Cc from the state in which only the friction of the engine 12 itself and the load on the auxiliary machine are applied. In particular, an engine stall may occur when the input shaft rotational speed Nin after engagement of the engagement element is low. After the time point t3, the engine rotational speed Ne rapidly decreases, and a change in the vehicle longitudinal G, that is, a shock during the traveling of the vehicle 10 occurs.

  8 and 9, when switching from the N position to the D position is performed, the control of the engagement side frictional engagement device Cc is changed based on the comparison between the synchronous rotational speed Nsin and the target engine rotational speed Net. Thus, a time chart in the case of suppressing engine stall is shown. FIG. 8 shows control when the synchronous rotational speed Nsin is lower than the target engine rotational speed Net. At time t1, switching from the N position to the D position is performed. The engine rotation speed Ne is slightly higher than the target idle rotation speed Nidle, and the input shaft rotation speed Nin indicates a rotation speed slightly lower than the target idle rotation speed Nidle. Although not shown in the figure, the synchronous rotational speed Nsin is calculated by multiplying the output shaft rotational speed Nout by the gear ratio γ at the gear stage established, and the synchronous rotational speed Nsin is equal to or less than a preset target engine rotational speed Net. It is determined whether or not. The clutch oil pressure command, that is, the clutch oil pressure command pressure Pc is increased from substantially zero to the quick fill command pressure P3, and the vehicle front-rear G, which is the weight acceleration G in the vehicle front-rear direction, indicates substantially zero, that is, coasting. At the time t2, the inertia phase of the engagement element, that is, the engagement is started, the engine rotation speed Ne and the input shaft rotation speed Nin start to decrease slightly, and the weight acceleration G also increases slightly. At t3, the engagement determination, that is, the synchronization completion determination is performed. When the synchronous rotation speed Nsin is lower than the target engine rotation speed Net, the final pressure increase to the command pressure P4 during engagement, which is called engagement increase, is It is not implemented at time t3. At time t4, when the difference between the engine rotational speed Ne and the input shaft rotational speed Nin is equal to or greater than a predetermined value B, the pressure is increased to the command pressure P4.

  In the time chart of FIG. 9, control when the synchronous rotational speed Nsin exceeds the target engine rotational speed Net is shown. The time t1 and the time t2 are the same as in FIG. When the synchronization completion determination is made at time t3, the synchronous rotation speed Nsin is equal to or higher than the target engine rotation speed Net, so that the final pressure increase command pressure P4 at the time of engagement, which is called engagement pressure increase, is increased. Done.

  As described above, according to the electronic control unit 40 of this embodiment, when the shift position is switched from the N position, which is the non-traveling position, to the D position, which is the traveling position, by operating the shift lever, the input shaft rotation speed. Nin continues to stay within a predetermined synchronization determination range Nsina including the synchronized rotational speed Nsin after the shift for a predetermined time ta or more, thereby determining whether the engagement side frictional engagement device Cc has been synchronized. In addition to this, the synchronous rotation speed Nsin of the input shaft rotation speed Nin when the shift position is switched from the non-traveling position N position to the traveling position D position by the operation of the shift lever 82 is When the value is lower than the value obtained by adding the predetermined value A to the target idle speed Nidle, the engagement side friction is further added as a condition for determining the completion of synchronization by further adding that the input shaft speed Nin is lower than the engine speed Ne by a predetermined value B or more. The synchronization completion determination of the engagement device Cc is performed. For this reason, the synchronous rotation speed Nsin of the input shaft rotation speed Nin when the shift position is switched from the non-traveling position N position to the traveling position D position by operating the shift lever 82 is the target idle rotation speed of the engine 12. When the target engine speed Net, which is a value obtained by adding a predetermined value A to Nidle, is exceeded, an error has occurred in the measured values of the engine speed sensor 70, the input shaft speed sensor 72, and the output shaft speed sensor 74. However, since the engine stall does not occur, it is possible to immediately increase the engagement hydraulic pressure supplied to the engagement-side frictional engagement device Cc, thereby preventing the synchronization completion determination from being delayed. Further, the synchronous rotational speed of the input shaft rotational speed Nin The input shaft rotational speed sensor 72Nsin is equal to or less than the target engine rotational speed Net which is a value obtained by adding a predetermined value A to the target idle rotational speed Nidle of the engine 12, and immediately engages frictional engagement. If there is a possibility that engine stall may occur when the engagement hydraulic pressure supplied to the combined device Cc is increased, the determination condition is that the difference between the engine rotational speed Ne and the input shaft rotational speed Nin is equal to or greater than a predetermined value B. Thus, the occurrence of engine stall can be suppressed.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  In the gear stage established at the travel position, the hydraulic command pressure of one of the two engagement elements is increased to the engagement hydraulic pressure immediately after the quick fill, but the hydraulic pressure based on the other embodiment is used. It is only necessary that the increase to the predetermined engagement hydraulic pressure is completed before the completion of synchronization of the engagement element to be controlled is determined.

  In the embodiment, the non-traveling position is the N position and the traveling position is the D position. However, the present invention is not limited to this. For example, the non-traveling position may be the P position. The same effect can be obtained even when the traveling position is set to the M operation position or the R position.

  In the present embodiment, the manual transmission operation position M for manually switching the gear position of the automatic transmission 22 together with the D position corresponding to traveling based on automatic transmission is provided, but not limited to the operation position M. The control of the present embodiment is also used as a traveling operation position that allows manual gear shifting by switching a plurality of types of gear shifting ranges, which are referred to as sequential operation positions S, with different gear positions on the high vehicle speed side (high side) where shifting is possible. Can do.

  In the above-described embodiment, the torque converter 20 is used in the vehicle 10. However, instead of the torque converter 20, a fluid coupling (fluid coupling) having no torque amplifying action may be used.

  Furthermore, an OWC (one-way clutch) may be provided in parallel with the second brake B2, which is a friction engagement device provided in the present embodiment. In this case, it is not necessary to engage the second brake B2 during forward travel.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 12: Engine 16: Power transmission device (vehicle power transmission device)
20: Torque converter (fluid transmission)
22: Automatic transmission (stepped automatic transmission)
30: Input shaft 40: Electronic control device (control device)
82: Shift lever (shift position selector)
Cc: engagement side frictional engagement device (engagement side frictional engagement element)
Ne: engine rotation speed Nin: input shaft rotation speed Nidle: target idle rotation speed Nsin: synchronous rotation speed Nsina: predetermined range ta: predetermined time B1, B2, C1 to C4: friction engagement device (friction engagement element)

Claims (1)

In a vehicle control device including an engine, a fluid transmission device, a stepped automatic transmission that performs a multiple-stage shift by a combination of engagement operations of a plurality of friction engagement elements, and a shift position selection device,
An input for transmitting the driving force of the engine to the stepped automatic transmission via the fluid transmission device when the synchronization of the engagement side frictional engagement element in the clutch-to-clutch shift for completing the establishment of the shift speed is established. The input shaft rotation speed of the shaft is determined based on continuing for a predetermined time or more in a predetermined range including the synchronous rotation speed after establishment of the shift stage, and when the synchronization completion is determined, A vehicle control device for increasing an engagement hydraulic pressure supplied to an engagement-side frictional engagement element,
If the synchronous rotational speed when the shift position selected by the shift position selection device switches from the non-traveling position to the traveling position is lower than a value obtained by adding a predetermined value to the target idle rotational speed of the engine, the synchronization is completed. The vehicle control apparatus further includes: a determination of completion of synchronization of the engagement-side frictional engagement element by adding that the input shaft rotation speed is lower than the engine rotation speed by a predetermined value or more as the determination condition of

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