JP2018013197A - Control device of power transmission device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that, at a gear change of a stepped automatic transmission, when performing synchronous determination by a stay of an input shaft rotational speed in the vicinity of a synchronous rotational speed for a prescribed determination time, and performing complete engagement by raising post-synchronous determination engagement hydraulic pressure, there may arise a risk that the accuracy of the synchronous determination is lowered as the input shaft rotational speed is low.SOLUTION: An accuracy of synchronous determination is improved by setting a synchronous determination range Nsina used for the synchronous determination wide as an output shaft rotational speed Nout used for the calculation of a synchronous rotational speed Nsin is low, and setting a synchronous determination time ta used for the sync determination long. The synchronous determination range Nsina is set wide as progressing toward a low gear change stage, and the synchronous determination time ta used for the synchronous determination is set long.SELECTED DRAWING: Figure 7

Description

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

  Provided between the input shaft to which the power of the drive source is transmitted and the output shaft to transmit the power to the drive wheels, and for vehicles that perform a multi-stage shift by a combination of engagement operations of a plurality of friction engagement elements. In the control device for the stepped automatic transmission, during the shift control, when the input shaft rotation speed continues within the synchronization determination range for a predetermined time or more, the shift end determination of the engagement side engagement element is performed, and the engagement side 2. Description of the Related Art A control device for a stepped automatic transmission for a vehicle that performs full engagement of the engagement side engagement element by increasing an engagement hydraulic pressure supplied to the engagement element is known. For example, this is the control device for a stepped automatic transmission for a vehicle described in Patent Document 1. In the control device for a stepped automatic transmission for a vehicle disclosed in Patent Document 1, a shift completion determination of the engagement-side engagement element is made when the input shaft rotation speed continues for a predetermined time or more during shift control. The engagement side engagement element is completely engaged by increasing the engagement hydraulic pressure based on the shift end determination, thereby making the engagement timing of the engagement side engagement element accurate. It suppresses the occurrence of shock during gear shifting and improves responsiveness.

JP 2004-257460 A

  By the way, when the shift end determination of the engagement side engagement element is performed based on the input shaft rotation speed of the stepped automatic transmission for a vehicle, for example, the detection accuracy becomes lower as the input shaft rotation speed is lower. If the shift end determination is made within a predetermined range of the input shaft rotation speed and for a predetermined time without considering that the detection accuracy varies depending on the input shaft rotation speed, an erroneous determination at a low input shaft rotation speed There is a possibility that the determination time may be longer and the determination time may be longer than necessary in order to avoid erroneous determination. For this reason, the occurrence of an erroneous determination at the end of the shift may cause an engagement shock or the drive source may blow up, and a longer determination time may cause a so-called hesitation that delays the completion of the shift. Further, when the output shaft rotation speed is used for the shift end determination, the output shaft rotation speed is lower than the input shaft rotation speed, so that the detection accuracy may be further lowered.

  The present invention has been made against the background of the above circumstances. The object of the present invention is to generate an engagement shock and drive source regardless of the input shaft rotation speed and the output shaft rotation speed at the end of engagement. It is intended to provide a control device for a stepped automatic transmission for a vehicle that is less likely to cause a delay in completion of gear shifting and a shift completion.

  The gist of the present invention is that: (a) engagement work of a plurality of friction engagement elements provided between an input shaft to which the power of the drive source is transmitted and an output shaft for transmitting the power to the drive wheels; (B) Clutch-to-clutch shift control executed by releasing the disengagement-side engagement element and engaging the engagement-side engagement element in a vehicular stepped automatic transmission that performs multiple-stage gearshifts by a combination of movements It is determined that synchronization of the engagement-side engagement element is completed on the condition that the input shaft rotation speed continues for the synchronization determination time within a preset synchronization determination range including the synchronized rotation speed after the shift. When the synchronization completion is determined, the vehicle stepped automatic transmission control device increases the engagement hydraulic pressure supplied to the engagement side engagement element, and (c) The synchronization judgment range is set wider as the output shaft speed decreases. Is, the synchronization determination time is that the output shaft rotational speed is set as the lower longer.

  According to this configuration, in the shift control of the stepped automatic transmission for a vehicle that performs a multiple-stage shift by a combination of the engagement operations of the plurality of friction engagement elements, the input shaft rotational speed is within a predetermined range for a predetermined time or more. The input shaft rotation that has been set in advance including the synchronized rotation speed after the shift used for determining the completion of the engagement and increasing the engagement hydraulic pressure by determining the completion of the synchronization of the engagement side engagement element by continuing. By setting the predetermined range of speed wider as the output shaft rotational speed becomes lower, and further setting the time during which the input shaft rotational speed is held in the predetermined range, that is, the predetermined time, as the output shaft rotational speed becomes lower, It is possible to improve the accuracy of the engagement end determination. As a result, the occurrence of engagement shock and the drive-up of the drive source are suppressed, and the delay in completing the shift when the output shaft rotational speed is high is 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 engagement element in each gear stage. 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 an engagement element. It is a figure explaining the case where the synchronous determination range in each synchronous rotation speed and each synchronous rotation speed is made constant. It is a figure explaining the case where the synchronous determination range in the synchronous rotational speed of each gear stage and each synchronous rotational speed is set so large that a rotational speed is low. It is a flowchart explaining the basic operation | movement of the gear stage change which is the principal part of the control action of the electronic controller of FIG. It is the figure which showed the example which sets synchronous determination time long, so that it is a low gear stage.

  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 (drive power source) 12, drive wheels 14, and a vehicle power transmission device 16 (hereinafter referred to as power transmission) provided in a power transmission path between the engine 12 and the drive wheels 14. Device 16). The power transmission device 16 includes a torque converter (fluid coupling) 20 and a vehicle stepped automatic transmission 22 (hereinafter referred to as an automatic transmission) disposed in a case 18 (see FIG. 2) as a non-rotating member attached to a vehicle body. 22), a differential gear device 26 in which a transmission output gear 24 (hereinafter also referred to as an output shaft 24) functioning as an output shaft of the automatic transmission 22 is connected to a ring gear 26a, and a differential gear device 26. And a pair of axles 28 and the like. 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 input shaft 30 which is an input rotation member of the automatic transmission 22, and in FIG. The lower half 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 is capable of transmitting power to a pump impeller (input member) 20p arranged to rotate around an axis RC and the input shaft 30. A turbine impeller (output member) 20t that is connected, 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 drive wheels 14 and functions as a plurality of hydraulic friction engagement devices (a first clutch C1 to a fourth clutch C4, a first clutch). As a stepped automatic transmission in which a plurality of gear stages (gear stages) having different gear ratios (gear ratios) are formed by selectively engaging either one brake B1 or second brake B2) It is a functioning 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 input shaft 30 is shifted and output from a transmission output gear 24 that functions as an output shaft.

  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, the second brake B2 (hereinafter simply referred to as a hydraulic friction engagement device unless otherwise distinguished) It is composed of a wet multi-plate type clutch and brake pressed by a hydraulic actuator, a band brake tightened by a hydraulic actuator, and the like.

  By controlling the engagement and disengagement of these hydraulic friction engagement devices, as shown in the engagement operation table of FIG. 3, the forward 8 stages and the reverse 1 are made according to the accelerator operation of the driver, the vehicle speed V, and the like. Each 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 (= input shaft rotational speed Nin / output shaft 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 device 46. It is appropriately determined by the gear ratio (= the number of teeth of the sun gear / the number of teeth of the ring gear).

  FIG. 4 is a circuit diagram showing the 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 hydraulic 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 an original pressure, and a manual valve 58 that mechanically switches the oil path in conjunction with the switching operation of the shift lever 80 are provided. ing. The manual valve 58 outputs the input line hydraulic pressure PL as the forward hydraulic pressure (D range pressure, drive hydraulic pressure) PD when the shift lever 80 is in the D operation position, and input when the shift lever 80 is in the R operation position. The line hydraulic pressure PL is output as a reverse hydraulic pressure (R range pressure, reverse hydraulic pressure) PR. Further, when the shift lever 80 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 the electronic control unit 40. The hydraulic pressures Pc1, Pc2, Pc3, Pc4, Pb1, Pb2 Are regulated independently. 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 hydraulic 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 hydraulic friction engagement device.

  Returning to FIG. 1, the vehicle 10 includes an electronic control unit 40 that determines whether the gear stage is engaged when the input shaft rotational speed Nin approaches the synchronous rotational speed of the gear stage after the shift. 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) of the input shaft 30 detected by the input shaft rotational speed sensor 72, and the output shaft rotational speed sensor 74 The transmission output gear rotation speed corresponding to the detected vehicle speed V, that is, the output shaft rotation speed Nout (rpm), the accelerator opening θacc (%) detected by the accelerator opening sensor 76, and the brake signal detected by the brake switch 78 A signal representing Bon or the like is 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 unit 40 stores in advance a predetermined relationship (shift map, shift diagram) with the vehicle speed V, that is, the output shaft rotation speed Nout and the accelerator opening θacc as variables, as the main part of the control function. Further, it has gear stage switching determining means 90 for determining the necessity of shifting and the gear stage after shifting by applying the actual vehicle speed V and the accelerator opening degree Acc. The electronic control unit 40 also includes a synchronous rotation speed calculation unit 92, a synchronization determination range time selection unit 94, a synchronization completion determination unit 96, and an engagement hydraulic pressure control unit 98. The shift to the gear stage is completed by determining the end of engagement of the hydraulic friction engagement device based on Nsin and increasing the engagement hydraulic pressure to complete the engagement.

  The gear stage switching determination means 90 determines a gear stage change based on the output shaft rotation speed Nout and the accelerator opening degree θacc, and selects the gear stage after the shift. The engagement oil pressure control means 98 is engaged with the release oil pressure of the disengagement hydraulic friction engagement device that is released during the shift, based on the determination of the gear position switching by the gear position switching determination means 90. The clutch-to-clutch shift is executed by controlling the engagement hydraulic pressure of the combined hydraulic friction engagement device based on a relationship (map) that is preset and stored. The synchronous rotation speed calculation means 92 multiplies the output shaft rotation speed Nout by the gear ratio (transmission ratio) γ at the gear stage established after the shift, thereby completing the synchronous rotation speed Nsin, that is, the inertia phase of the hydraulic friction engagement device. A synchronous rotational speed Nsin that becomes the input shaft rotational speed Nin after the combination is calculated. The synchronization determination range time selection means 94 is a synchronization determination range Nsina that is an input shaft rotation speed range corresponding to a gear stage that is established after a shift and a calculated synchronization rotation speed Nsin based on a predetermined and stored relationship (map). (Rpm) is selected, and the synchronization determination time ta (sec) is selected. The synchronization completion determination unit 96 is configured to maintain the input shaft rotation speed Nin within the synchronization determination range Nsina that includes the synchronization rotation speed Nsin for a predetermined synchronization determination time ta or longer, thereby allowing the hydraulic frictional engagement. Determine completion of synchronization of the combined device. When it is determined that the synchronization is completed, the engagement hydraulic pressure control means 98 further increases the hydraulic pressure command value of the hydraulic friction engagement device that is engaged after the gear shift to ensure the engagement.

  In FIG. 5, an example of the relationship between the output shaft rotational speeds Nout and Nin in the first to third speeds is indicated by a solid line. The solid lines are the input shaft rotational speed Nin obtained by multiplying the output shaft rotational speed Nout by the gear ratio γ from the first speed to the third speed, that is, the synchronous rotational speed Nsin from the first speed to the third speed. The input shaft rotational speed Nin between the broken lines indicates the synchronization determination range Nsina. For example, at the first output shaft rotational speed Nout1, the value Nin2 on the solid line obtained by multiplying the output shaft rotational speed Nout1 by the gear ratio γ indicates the synchronous rotational speed Nsin, and the range of the input shaft rotational speed Nin from Nin1 to Nin3 is The synchronization determination range Nsina is shown. In FIG. 5, the synchronization determination at the first speed when the output shaft rotational speed is Nout1 is a predetermined synchronization determination for the input shaft rotational speed within the synchronization determination range Nsina, that is, within the range from Nin1 to Nin3. This is performed depending on whether or not the time ta is exceeded. In FIG. 5, the synchronization determination range Nsina is set to be constant regardless of the magnitude of the output shaft rotation speed Nout.

  As described above, the rotational speed sensors such as the input shaft rotational speed sensor 72 and the output shaft rotational speed sensor 74 detect the number of pulses generated with the rotation of the input shaft 30 and the output shaft 24, thereby obtaining the input shaft rotational speed Nin. The output shaft rotational speed Nout is detected, and the input shaft rotational speed sensor 72 has more pulses per shaft rotation in the input shaft rotational speed sensor 72 and the output shaft rotational speed sensor 74. In addition, the output shaft rotational speed Nout is lower than the input shaft rotational speed Nin at a low gear stage, so that the number of pulses per one shaft rotation is reduced, thereby reducing the rotational speed detection accuracy. Further, the detection accuracy is further lowered at a low rotational speed. Further, since the synchronous rotational speed Nsin is calculated by multiplying the output shaft rotational speed Nout, which is less accurate than the input shaft rotational speed Nin, by the gear ratio γ, the error further increases.

  FIG. 6 shows an example of the relationship between the output shaft rotational speeds Nout and Nin from the first speed to the third speed in the present embodiment. The relationship between the output shaft rotational speeds Nout and Nin in the first to third speeds indicated by the solid line is the same as in FIG. However, the synchronization determination range Nsina indicated by the broken line is different from that shown in FIG. 5 in that the detection accuracy of the rotation speed is reduced at a low rotation speed, and the synchronization determination range Nsina is smaller as the input shaft rotation speed Nin is higher. The range of the synchronization determination range Nsina is set larger as the input shaft rotational speed Nin is lower. Furthermore, in the present embodiment, the synchronization determination time ta is set to be shorter as the input shaft rotation speed Nin is larger, and the synchronization determination time ta is set to be longer as the input shaft rotation speed Nin is smaller.

  FIG. 7 shows the hydraulic friction engagement in which the main part of the control operation of the electronic control unit 40, that is, the gear shift is determined, and the input shaft rotational speed Nin remains within the synchronization determination range Nsina for a predetermined synchronization determination time ta. It is a flowchart explaining the control action | operation when the engagement of an apparatus is determined, and is repeatedly performed.

  In FIG. 7, in step (hereinafter, step is omitted) S10 corresponding to the function of the gear stage switching determination means 90, it is determined whether or not the gear stage switching determination has been performed. If this determination is negative, this routine is terminated. If the determination in S10 is affirmative, the gear stage is selected in S20 corresponding to the function of the gear stage switching determination means 90. In S30 corresponding to the function of the engagement hydraulic control means 98, the engagement of the hydraulic friction engagement device to be engaged after the shift is set in advance together with the release of the hydraulic friction engagement device to be released after the shift. Control is based on the stored map. In S40 corresponding to the function of the synchronous rotational speed calculation means 92, the synchronous rotational speed Nsin is calculated by multiplying the output shaft rotational speed Nout by the gear ratio γ at the selected gear stage. Further, in S50 corresponding to the function of the synchronization determination range time selection means 94, the synchronization determination range Nsina of the post-shift gear stage is selected based on the shift stage after the shift and the input shaft rotational speed Nin. In S60 corresponding to the function of the synchronization determination range time selection means 94, the synchronization determination time ta is selected based on the gear position after the shift and the output shaft rotation speed Nout. In S70 corresponding to the function of the synchronization completion determination means 96, it is determined whether or not the input shaft rotation speed Nin stays within the range where the synchronization determination range Nsina is increased or decreased from the synchronization rotation speed Nsin for a predetermined synchronization determination time ta or more. If this determination is negative, the determination is repeated. If this determination is affirmative, in S80 corresponding to the function of the engagement hydraulic control means 98, the hydraulic pressure command value to the hydraulic friction engagement device engaged after the shift is increased to the line pressure. .

  As described above, in the present embodiment, in the automatic transmission 22 that performs a multi-stage shift by a combination of a plurality of hydraulic friction engagement devices, the engagement of the hydraulic friction engagement devices that are engaged after the shift is input. In the electronic control unit 40 of the automatic transmission 22 that determines the synchronization of the hydraulic friction engagement device by keeping the shaft rotational speed Nin within a predetermined synchronization determination range Nsina for a predetermined synchronization determination time ta or longer, the electronic control device 40 of the automatic transmission 22 determines the synchronization completion. The synchronization determination range Nsina to be used is set wider as the output shaft rotation speed Nout is lower, and the synchronization determination time ta is set longer as the output shaft rotation speed Nout is lower, thereby improving the accuracy of the synchronization completion determination. It becomes. As a result, the occurrence of engagement shock and drive-up of the drive source are suppressed, and the delay of the shift completion, that is, the delay of the shift output when the output shaft rotational speed Nout is high is suppressed.

  Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above embodiment are given the same reference numerals and description thereof is omitted.

  In the present embodiment, the range of the synchronization determination range Nsina is set larger as the gear shifts to a lower gear, and the synchronization determination time ta is set longer as the gear shifts to a lower gear. . FIG. 8 shows an example in which the synchronization determination time ta is set longer as the gear shifts to a lower gear and as the output shaft rotational speed Nout decreases. The flowchart for explaining the control operation is the same as that of the first embodiment and is repeatedly executed.

  According to the second embodiment, in the automatic transmission 22 that performs a multiple-stage shift by a combination of a plurality of hydraulic friction engagement devices, the engagement of the hydraulic friction engagement devices that are engaged after the shift is determined as the input shaft rotation speed. In the electronic control unit 40 of the automatic transmission 22 for determining the synchronization of the hydraulic friction engagement device by keeping Nin within a predetermined synchronization determination range Nsina for a predetermined synchronization determination time ta or more, the synchronization determination used for determining the synchronization completion By setting the range Nsina wider as the output shaft rotational speed Nout decreases, and by setting the synchronization determination time ta longer as the output shaft rotational speed Nout decreases, it is possible to improve the accuracy of the engagement end determination. In addition, the synchronization determination range Nsina is set to be larger as the gear is shifted to a lower gear, and the synchronization determination time ta is set longer as the gear is shifted to a lower gear, thereby further improving the accuracy of determination of synchronization completion. As a result, the occurrence of an engagement shock, the drive source blowing up, and the delay in completing the shift, that is, the delay in the shift output is further 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 above-described embodiment, the engine 12 is used for the vehicle 10, but instead of the engine 12, for example, an electric motor or the like may be used as a driving power source.

  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.

  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.

12: Engine (drive source)
22: Automatic transmission (stepped automatic transmission for vehicles)
24: Transmission output gear (output shaft)
30: Input shaft 40: Electronic control device (control device)
C1-C4, B1, B2: Hydraulic friction engagement device (engagement element)
Nin: Input shaft rotational speed Nout: Output shaft rotational speed Nsin: Synchronous rotational speed Nsina: Synchronization determination range ta: Synchronization determination time

Claims (1)

For vehicles that perform multiple-stage shifts by a combination of engagement operations of a plurality of friction engagement elements provided between an input shaft that transmits the power of the drive source and an output shaft that transmits the power to the drive wheels In stepped automatic transmission,
A preset synchronization determination range in which the input shaft rotation speed includes the synchronous rotation speed after the shift during the clutch-to-clutch shift control executed by releasing the release-side engagement element and engaging the engagement-side engagement element. If it is determined that the synchronization of the engagement side engagement element is completed on the condition that the synchronization determination time has continued, and if the determination of the completion of synchronization is made, supply to the engagement side engagement element A control device for the stepped automatic transmission for a vehicle that increases the engagement hydraulic pressure to be
The synchronization determination range is set wider as the output shaft rotation speed decreases,
The control apparatus for a stepped automatic transmission for a vehicle, wherein the synchronization determination time is set longer as the output shaft rotational speed is lower.

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