JP4900522B2 - Powertrain control device and control method - Google Patents

Description

The present invention relates to a power train control device and control method , and more particularly to a technique for controlling an engagement element for forming a gear stage.

  2. Description of the Related Art Conventionally, there is known an automatic transmission that changes gears by changing a combination of engaging elements among engaging elements such as a clutch and a brake. In such an automatic transmission, it is formed by engaging two different engaging elements from a gear stage formed by engaging any two engaging elements among a plurality of engaging elements. In some cases, shifting to the gear position to be performed is required.

  Japanese Patent Laid-Open No. 2002-195401 (Patent Document 1) requires the operation of four engaging elements when shifting from the first gear to the second gear, and the first gear is the first gear. Disclosed is a shift control device for an automatic transmission that is achieved by engagement of one engagement element and a second engagement element, and the second shift stage is achieved by engagement of the third engagement element and the fourth engagement element. To do. The shift control device described in Patent Literature 1 includes a shift control unit that controls the state of the second engagement element in accordance with the state of the first engagement element.

  According to the shift control device described in this publication, the second engagement of the second engagement unit according to the state of one of the first engagement elements released at the time of a shift from the first shift step to the second shift step. The state of the combined element is controlled. Therefore, the release of these two engagement elements can be prevented from proceeding in a disorderly manner. Therefore, smooth shift control for preventing engine blow can be realized by matching the released state of the first and second engagement elements with the progress of engagement of the third and fourth engagement elements on the engagement side. It becomes.

JP 2002-195401 A

  However, like the shift control device described in Japanese Patent Application Laid-Open No. 2002-195401, the state of the other engagement element is changed according to the state of one of the two engagement elements released by the shift. When controlled, the shift can proceed with both engagement elements having engagement forces. Therefore, release of the engaging element that forms the gear stage before the shift is delayed. As a result, the progress of the shift can be delayed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an automatic transmission control device, a control method, a program for realizing the method, and a program for the automatic transmission that can perform speed change quickly. It is to provide a recorded recording medium.

  In the control device for an automatic transmission according to the first invention, the first gear stage is formed by engaging the first engagement element and the second engagement element, and the second engagement element and the second engagement element The second gear stage is formed by engaging the three engagement elements, and the third gear stage is formed by engaging the third engagement element and the fourth engagement element. It is a control device of the machine. The control device determines whether or not to perform a shift from the third gear to the first gear, and determines to perform a shift from the third gear to the first gear. If so, before engaging the first and second engagement elements, release the fourth engagement element and control the third engagement element to have an engagement force. Control means. The control method for the automatic transmission according to the eighth invention has the same requirements as the control device for the automatic transmission according to the first invention.

  According to the first or eighth invention, the first gear stage is formed by engaging the first engagement element and the second engagement element. A second gear stage is formed by engaging the second engagement element and the third engagement element. A third gear stage is formed by engaging the third engagement element and the fourth engagement element. When it is determined that a shift from the third gear stage to the first gear stage is to be performed, the fourth engagement element is released before engaging the first engagement element and the second engagement element. And the third engagement element is controlled to have an engagement force. As a result, one of the two engagement elements forming the gear stage before the shift can be released, and only the other can have an engagement force. By releasing one of the engaging elements, the shift can be started quickly. Therefore, the start of the shift can be accelerated compared to the case where the state of the other engagement element is controlled according to the state of one of the two engagement elements released by the shift. As a result, it is possible to provide a control device or control method for an automatic transmission that can perform speed change quickly.

  In addition to the configuration of the first invention, the control device for the automatic transmission according to the second invention is such that the rotational speed of the input shaft of the automatic transmission is the first during the shift from the third gear stage to the first gear stage. The apparatus further includes means for controlling the second engagement element to be engaged in accordance with a timing at which the rotational speed is the same as the synchronous rotational speed of the input shaft of the automatic transmission in the second gear stage. A control method for an automatic transmission according to a ninth aspect has the same requirements as those of the control device for an automatic transmission according to the second aspect.

  According to the second or ninth invention, during the shift from the third gear stage to the first gear stage, the rotational speed of the input shaft of the automatic transmission is synchronized with the input shaft of the automatic transmission in the second gear stage. The second engagement element is engaged in accordance with the timing at which the rotation speed is the same as the rotation speed. Thus, the timing at which the rotational speed of the input shaft becomes the same as the synchronous rotational speed of the input shaft in the second gear stage, and the engagement element that is engaged when the second gear stage is formed are engaged with each other. It is possible to match the timing having Therefore, it is possible to reduce a shock at the time of shifting.

  In addition to the configuration of the second invention, the control device for the automatic transmission according to the third invention releases the third engagement element after the second engagement element is engaged, and Means are further provided for controlling the engagement element to engage. A control method for an automatic transmission according to a tenth aspect of the invention has the same requirements as those of the control device for an automatic transmission according to the third aspect of the invention.

  According to the third or tenth invention, after the second engagement element is engaged, the third engagement element is released and the first engagement element is engaged. Thereby, the shift to the first gear stage can be completed.

  In the automatic transmission control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the automatic transmission is restricted in rotation by the engagement force of the third engagement element. A rotating member is provided. The control device further includes setting means for setting a target value of the engagement force of the third engagement element according to the inertia of the rotating member. The control means releases the fourth engagement element before engaging the first engagement element and the second engagement element, and the target value in which the engagement force of the third engagement element is set. Engaging force control means for controlling to become. An automatic transmission control method according to an eleventh aspect of the invention has the same requirements as the automatic transmission control device according to the fourth aspect of the invention.

  According to the fourth or eleventh invention, the automatic transmission is provided with the rotating member whose rotation is restricted by the engaging force of the third engaging element. A target value of the engagement force of the third engagement element is set according to the inertia of the rotation member. When shifting from the third gear stage to the first gear stage, the fourth engagement element is released and the first engagement element is released before engaging the first engagement element and the second engagement element. The engagement force of the engagement element 3 is set to the set target value. Thereby, for example, the engagement force of the third engagement element can be lowered to the minimum engagement force that can counter the inertial force of the rotation member, that is, the minimum engagement force that can restrict the rotation of the rotation member. . Therefore, it is possible to prevent the rotation number of the rotating member from becoming excessive during the speed change, and to release the third engaging element promptly. As a result, by preventing the rotation speed of the input shaft of the automatic transmission interlocking with the rotating member from becoming excessive, it is possible to reduce a shock that may occur at the time of shifting, and it is possible to advance the shifting promptly. .

  In the control apparatus for an automatic transmission according to the fifth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the engagement force control means is configured to engage the first engagement element and the second engagement element before The fourth engagement element is released and the third engagement element is controlled so that the engagement force of the third engagement element becomes a set target value, and the third engagement element is engaged until the second engagement element is engaged. Means are provided for controlling the engagement force of the elements to be a set target value. An automatic transmission control method according to a twelfth aspect of the invention has the same requirements as the automatic transmission control device according to the fifth aspect of the invention.

  According to the fifth or twelfth invention, when shifting from the third gear stage to the first gear stage, before engaging the first engagement element and the second engagement element, the fourth gear stage is performed. The engagement force of the third engagement element is released and the engagement force of the third engagement element is set to the set target value, and the engagement force of the third engagement element is increased until the second engagement element is engaged. The set target value is set. Thereby, for example, the state where the engagement force of the third engagement element is lowered to the minimum engagement force that can regulate the rotation speed of the rotation member can be maintained until the second engagement element is engaged. it can. Therefore, it is possible to reduce a shock that may occur when the second engagement element is engaged.

  In addition to the configuration of the fourth or fifth invention, the automatic transmission control device according to the sixth invention further comprises means for detecting the rate of increase in the rotational speed of the input shaft of the automatic transmission. Torque is transmitted to the rotating member from the input shaft of the automatic transmission. The setting means sets the target value of the engagement force of the third engagement element according to the rate of increase of the input shaft of the automatic transmission, thereby setting the target value of the engagement force of the third engagement element to the rotating member. The target setting means for setting according to the inertia of is included. A control method for an automatic transmission according to a thirteenth invention has the same requirements as the control device for an automatic transmission according to the sixth invention.

  According to the sixth or thirteenth invention, by setting the target value of the engagement force of the third engagement element according to the rate of increase of the input shaft of the automatic transmission that transmits torque to the rotating member, The target value of the engaging force of the engaging element can be set according to the inertia of the rotating member.

  In the control device for an automatic transmission according to the seventh invention, in addition to the configuration of the sixth invention, the target setting means has a third function that is lower when the rate of increase of the input shaft of the automatic transmission is large than when it is low. Means for setting the target value of the engagement force of the third engagement element in accordance with the inertia of the rotating member by setting the target value of the engagement force of the engagement element larger. An automatic transmission control method according to a fourteenth aspect of the invention has the same requirements as the automatic transmission control device according to the seventh aspect of the invention.

  According to the seventh or fourteenth invention, when the rate of increase of the input shaft of the automatic transmission is large, it can be said that the inertial force of the rotating member is greater than when the rate of increase is small. The target value is set larger. Thereby, the greater the inertial force of the rotating member, the greater the engaging force of the third rotating member. Therefore, it is possible to prevent the inertial force of the rotating member from becoming excessive during the shift.

  A program according to the fifteenth invention is a program for causing a computer to implement the control method according to any of the eighth to fourteenth inventions, and the recording medium according to the sixteenth invention is any one of the eighth to fourteenth inventions. It is a computer-readable recording medium which recorded the program which makes a computer implement | achieve the control method concerning.

  According to the fifteenth or sixteenth invention, the control method for the automatic transmission according to any of the eighth to fourteenth inventions can be realized by using a computer (which may be general purpose or dedicated).

It is a schematic block diagram which shows the power train of a vehicle. It is a skeleton figure which shows the planetary gear unit of an automatic transmission. It is a figure which shows the operation | movement table | surface of an automatic transmission. It is a figure which shows the hydraulic circuit of an automatic transmission. It is a functional block diagram of ECU. It is a timing chart which shows the command oil pressure etc. of a friction engagement element. It is a figure which shows the map used in order to calculate torque down amount. It is a timing chart which shows an engine output torque etc. It is a flowchart (the 1) which shows the control structure of the program which ECU performs. It is a flowchart (the 2) which shows the control structure of the program which ECU performs.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A vehicle equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. This vehicle is an FF (Front engine Front drive) vehicle. A vehicle other than FF may be used.

  The vehicle includes an engine 1000, an automatic transmission 2000, a planetary gear unit 3000 that forms part of the automatic transmission 2000, a hydraulic circuit 4000 that forms part of the automatic transmission 2000, a differential gear 5000, a drive shaft 6000, Front wheel 7000 and ECU (Electronic Control Unit) 8000 are included. The control device according to the present embodiment is realized, for example, by executing a program recorded in ROM (Read Only Memory) 8300 of ECU 8000. The program executed by ECU 1000 may be recorded on a recording medium such as a CD (Compact Disc) or a DVD (Digital Versatile Disc) and distributed to the market.

  Engine 1000 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated. In addition to engine 1000, a motor may be used as a power source.

  Automatic transmission 2000 is connected to engine 1000 via torque converter 3200. Automatic transmission 2000 changes the rotational speed of the crankshaft to a desired rotational speed by forming a desired gear stage.

  The output gear of automatic transmission 2000 is meshed with differential gear 5000. A drive shaft 6000 is connected to the differential gear 5000 by spline fitting or the like. Power is transmitted to the left and right front wheels 7000 via the drive shaft 6000.

  The ECU 8000 includes an air flow meter 8002, a position switch 8006 of a shift lever 8004, an accelerator opening sensor 8010 of an accelerator pedal 8008, a pedaling force sensor 8014 of a brake pedal 8012, a throttle opening sensor 8018 of an electronic throttle valve 8016, An engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, and an oil temperature sensor 8026 are connected via a harness or the like.

  Air flow meter 8002 detects the amount of air taken into engine 1000 and transmits a signal representing the detection result to ECU 8000. The position (position) of shift lever 8004 is detected by position switch 8006, and a signal representing the detection result is transmitted to ECU 8000. Corresponding to the position of the shift lever 8004, the gear stage of the automatic transmission 2000 is automatically formed. Further, a manual shift mode in which the driver can select an arbitrary gear stage may be selected according to the driver's operation.

  Accelerator opening sensor 8010 detects the opening of accelerator pedal 8008 and transmits a signal representing the detection result to ECU 8000. The pedaling force sensor 8014 detects the pedaling force of the brake pedal 8012 (the force with which the driver steps on the brake pedal 8012), and transmits a signal representing the detection result to the ECU 8000.

  The throttle opening sensor 8018 detects the opening of the electronic throttle valve 8016 whose opening is adjusted by the actuator, and transmits a signal representing the detection result to the ECU 8000. Electronic throttle valve 8016 adjusts the amount of air taken into engine 1000 (output of engine 1000).

  Instead of or in addition to the electronic throttle valve 8016, the amount of air drawn into the engine 1000 can be reduced by changing the lift amount of the intake valve (not shown) or the exhaust valve (not shown) and the opening / closing phase. You may make it adjust.

  Engine rotation speed sensor 8020 detects the rotation speed of the output shaft (crankshaft) of engine 1000 and transmits a signal representing the detection result to ECU 8000. Input shaft rotational speed sensor 8022 detects input shaft rotational speed NI of automatic transmission 2000 (turbine rotational speed NT of torque converter 3200), and transmits a signal representing the detection result to ECU 8000. Output shaft rotational speed sensor 8024 detects output shaft rotational speed NO of automatic transmission 2000 and transmits a signal representing the detection result to ECU 8000. The vehicle speed is calculated (detected) from the output shaft rotational speed NO.

  Oil temperature sensor 8026 detects the temperature (oil temperature) of oil (ATF: Automatic Transmission Fluid) used for the operation and lubrication of automatic transmission 2000, and transmits a signal indicating the detection result to ECU 8000.

  The ECU 8000 includes an air flow meter 8002, a position switch 8006, an accelerator opening sensor 8010, a pedaling force sensor 8014, a throttle opening sensor 8018, an engine speed sensor 8020, an input shaft speed sensor 8022, an output shaft speed sensor 8024, and an oil temperature sensor. On the basis of a signal sent from 8026 and the like, a map and a program stored in the ROM 8300, the devices are controlled so that the vehicle is in a desired traveling state.

  In the present embodiment, ECU 8000, when shift lever 8004 is in the D (drive) position and D (drive) range is selected as the shift range of automatic transmission 2000, out of 1st to 6th gears The automatic transmission 2000 is controlled so that any one of the gear positions is formed. The automatic transmission 2000 can transmit the driving force to the front wheels 7000 by forming any one of the first to sixth gears. In the D range, it may be possible to form a higher gear than the sixth gear, that is, a seventh gear or an eighth gear. The gear stage to be formed is determined based on a shift diagram created in advance by experiments or the like using the vehicle speed and the accelerator opening as parameters.

  As shown in FIG. 1, ECU 8000 includes an engine ECU 8100 that controls engine 1000 and an ECT (Electronic Controlled Transmission) _ECU 8200 that controls automatic transmission 2000.

  Engine ECU 8100 and ECT_ECU 8200 are configured to be able to transmit and receive signals to and from each other. In the present embodiment, engine ECU 8100 transmits to ECT_ECU 8200 a signal representing the accelerator opening, a signal representing output torque TEKL converted from the intake air amount, and the like. From ECT_ECU 8200 to engine ECU 8100, a signal indicating a torque request amount, a torque down amount, a torque up amount, and the like determined as torque to be output by engine 1000 is transmitted.

  The planetary gear unit 3000 will be described with reference to FIG. Planetary gear unit 3000 is connected to a torque converter 3200 having an input shaft 3100 coupled to a crankshaft. Planetary gear unit 3000 includes first set 3300 of planetary gear mechanisms, second set 3400 of planetary gear mechanisms, output gear 3500, B1 brake 3610, B2 brake 3620 and B3 brake 3630 fixed to gear case 3600, and C1. Clutch 3640 and C2 clutch 3650, and one-way clutch F3660 are included.

  The first set 3300 is a single pinion type planetary gear mechanism. First set 3300 includes sun gear S (UD) 3310, pinion gear 3320, ring gear R (UD) 3330, and carrier C (UD) 3340.

  Sun gear S (UD) 3310 is coupled to output shaft 3210 of torque converter 3200. Pinion gear 3320 is rotatably supported by carrier C (UD) 3340. Pinion gear 3320 is in mesh with sun gear S (UD) 3310 and ring gear R (UD) 3330.

  Ring gear R (UD) 3330 is fixed to gear case 3600 by B3 brake 3630. Carrier C (UD) 3340 is fixed to gear case 3600 by B1 brake 3610.

  The second set 3400 is a Ravigneaux type planetary gear mechanism. The second set 3400 includes a sun gear S (D) 3410, a short pinion gear 3420, a carrier C (1) 3422, a long pinion gear 3430, a carrier C (2) 3432, a sun gear S (S) 3440, and a ring gear R. (1) (R (2)) 3450.

  Sun gear S (D) 3410 is coupled to carrier C (UD) 3340. Short pinion gear 3420 is rotatably supported by carrier C (1) 3422. Short pinion gear 3420 is in mesh with sun gear S (D) 3410 and long pinion gear 3430. Carrier C (1) 3422 is coupled to output gear 3500.

  Long pinion gear 3430 is rotatably supported by carrier C (2) 3432. Long pinion gear 3430 is in mesh with short pinion gear 3420, sun gear S (S) 3440, and ring gear R (1) (R (2)) 3450. Carrier C (2) 3432 is coupled to output gear 3500.

  Sun gear S (S) 3440 is coupled to output shaft 3210 of torque converter 3200 by C1 clutch 3640. Ring gear R (1) (R (2)) 3450 is fixed to gear case 3600 by B2 brake 3620 and connected to output shaft 3210 of torque converter 3200 by C2 clutch 3650. The ring gear R (1) (R (2)) 3450 is connected to the one-way clutch F3660, and cannot rotate when the first gear is driven.

  Engagement of C2 clutch 3650 restricts rotation of rotating member 3212 and ring gear R (1) (R (2)) 3450 connected to the input shaft of automatic transmission 2000, that is, output shaft 3210 of torque converter 3200. The Further, the rotation of the rotating member 3212 is restricted by the engagement of the C1 clutch 3640. Torque is transmitted from the input shaft of automatic transmission 2000 to rotating member 3212.

  The one-way clutch F3660 is provided in parallel with the B2 brake 3620. That is, the outer race of the one-way clutch F3660 is fixed to the gear case 3600, and the inner race is connected to the ring gear R (1) (R (2)) 3450 via the rotation shaft.

  FIG. 3 shows an operation table showing the relationship between each gear position and the operation state of each clutch and each brake. By operating each brake and each clutch with the combinations shown in this operation table, a forward gear stage of 1st to 6th speed and a reverse gear stage are formed.

  The main part of the hydraulic circuit 4000 will be described with reference to FIG. The hydraulic circuit 4000 is not limited to the one described below.

  The hydraulic circuit 4000 includes an oil pump 4004, a primary regulator valve 4006, a manual valve 4100, a solenoid modulator valve 4200, an SL1 linear solenoid (hereinafter referred to as SL (1)) 4210, and an SL2 linear solenoid (hereinafter referred to as “the solenoid valve”). 4220, SL3 linear solenoid (hereinafter referred to as SL (3)) 4230, SL4 linear solenoid (hereinafter referred to as SL (4)) 4240, and SLT linear solenoid (hereinafter referred to as SL (2)). , SLT) 4300 and a B2 control valve 4500.

  Oil pump 4004 is connected to the crankshaft of engine 1000. As the crankshaft rotates, the oil pump 4004 is driven to generate hydraulic pressure. The hydraulic pressure generated by the oil pump 4004 is regulated by the primary regulator valve 4006 to generate a line pressure.

  Primary regulator valve 4006 operates using the throttle pressure regulated by SLT 4300 as a pilot pressure. The line pressure is supplied to the manual valve 4100 via the line pressure oil passage 4010.

  Manual valve 4100 includes a drain port 4105. From the drain port 4105, the oil pressure in the D range pressure oil passage 4102 and the R range pressure oil passage 4104 is discharged. When the spool of the manual valve 4100 is in the D position, the line pressure oil passage 4010 and the D range pressure oil passage 4102 are communicated, and hydraulic pressure is supplied to the D range pressure oil passage 4102. At this time, the R range pressure oil passage 4104 and the drain port 4105 are communicated, and the R range pressure of the R range pressure oil passage 4104 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the R position, the line pressure oil passage 4010 and the R range pressure oil passage 4104 are communicated, and the oil pressure is supplied to the R range pressure oil passage 4104. At this time, the D range pressure oil passage 4102 and the drain port 4105 are communicated, and the D range pressure in the D range pressure oil passage 4102 is discharged from the drain port 4105.

  When the spool of the manual valve 4100 is in the N position, both the D range pressure oil passage 4102 and the R range pressure oil passage 4104 are connected to the drain port 4105, and the D range pressure and R of the D range pressure oil passage 4102 are communicated. The R range pressure of the range pressure oil passage 4104 is discharged from the drain port 4105.

  The hydraulic pressure supplied to the D range pressure oil passage 4102 is finally supplied to the B1 brake 3610, the B2 brake 3620, the C1 clutch 3640, and the C2 clutch 3650. The hydraulic pressure supplied to the R range pressure oil passage 4104 is finally supplied to the B2 brake 3620.

  The solenoid modulator valve 4200 adjusts the hydraulic pressure (solenoid modulator pressure) supplied to the SLT 4300 to a constant pressure using the line pressure as the original pressure.

  SL (1) 4210 regulates the hydraulic pressure supplied to the C1 clutch 3640. SL (2) 4220 regulates the hydraulic pressure supplied to C2 clutch 3650. SL (3) 4230 regulates the hydraulic pressure supplied to the B1 brake 3610. SL (4) 4240 regulates the hydraulic pressure supplied to the B3 brake 3630.

  The SLT 4300 adjusts the solenoid modulator pressure in accordance with a control signal from the ECU 8000 based on the accelerator opening detected by the accelerator opening sensor 8010, and generates a throttle pressure. The throttle pressure is supplied to the primary regulator valve 4006 via the SLT oil passage 4302. The throttle pressure is used as a pilot pressure for the primary regulator valve 4006.

  SL (1) 4210, SL (2) 4220, SL (3) 4230, SL (4) 4240, and SLT 4300 are controlled by a control signal transmitted from ECU 8000.

  The B2 control valve 4500 selectively supplies the hydraulic pressure from one of the D range pressure oil passage 4102 and the R range pressure oil passage 4104 to the B2 brake 3620. A D range pressure oil passage 4102 and an R range pressure oil passage 4104 are connected to the B2 control valve 4500. The B2 control valve 4500 is controlled by the hydraulic pressure supplied from the SL solenoid valve (not shown) and the SLU solenoid valve (not shown) and the biasing force of the spring.

  When the SL solenoid valve is off and the SLU solenoid valve is on, the B2 control valve 4500 is in the state on the left side in FIG. In this case, the B2 brake 3620 is supplied with the hydraulic pressure adjusted from the D range pressure using the hydraulic pressure supplied from the SLU solenoid valve as a pilot pressure.

  When the SL solenoid valve is on and the SLU solenoid valve is off, the B2 control valve 4500 is in the state on the right side in FIG. In this case, the R range pressure is supplied to the B2 brake 3620.

  The function of ECU 8000 will be described with reference to FIG. The functions of ECU 8000 described below may be realized by hardware or may be realized by software.

  The ECU 8000 includes a shift determination unit 8400, a first control unit 8401, a second control unit 8402, a third control unit 8403, a torque reduction unit 8410, an actual change rate detection unit 8420, and a target engagement pressure setting unit. 8430 and torque increasing portion 8440.

  Shift determination unit 8400 determines whether or not to downshift from the fifth gear to the second gear or from the sixth gear to the third gear. Whether or not to downshift is determined, for example, according to a shift diagram having vehicle speed and accelerator opening as parameters.

  First control unit 8401 shifts from the fifth gear stage formed by engaging B3 brake 3630 and C2 clutch 3650 to the second gear stage formed by engaging C1 clutch 3640 and B1 brake 3610. When downshifting, the B3 brake 3630 is released before the C1 clutch 3640 and the B1 brake 3610 are engaged, and the C2 clutch 3650 is controlled to have an engaging force.

  Further, the first control unit 8401 starts from the sixth gear that is formed by engaging the B1 brake 3610 and the C2 clutch 3650, and the third gear that is formed by engaging the C1 clutch 3640 and the B3 brake 3630. When downshifting to a stage, before engaging the C1 clutch 3640 and the B3 brake 3630, the B1 brake 3610 is released, and the C2 clutch 3650 is controlled to have an engaging force.

  The engagement force is controlled by changing the engagement pressure of the friction engagement element, that is, the hydraulic pressure supplied to the friction engagement element. The engagement pressure of the C2 clutch 3650 is reduced to the same pressure as the target engagement pressure set by the target engagement pressure setting unit 8430. A method for setting the target engagement pressure will be described later.

  When the second control unit 8402 downshifts from the fifth gear to the second gear or from the sixth gear to the third gear, when the time T (1) has elapsed after the start of the downshift, the C1 clutch 3640 Engage.

  In the C1 clutch 3640, the turbine rotational speed NT of the torque converter 3200, that is, the input shaft rotational speed NI of the automatic transmission 2000 is the same as the synchronous rotational speed calculated by multiplying the output shaft rotational speed NO by the gear ratio of the fourth gear. Engage with the timing of the rotational speed.

  After engaging the C1 clutch 3640, the third control unit 8403 releases the C2 clutch 3650 and engages the B1 brake 3610 or the B3 brake 3630. More specifically, when the time T (2) elapses after the C1 clutch 3640 is engaged, the engagement pressure of the C2 clutch 3650 is gradually reduced at a predetermined decrease rate. Eventually, the C2 clutch 3650 is released.

  Thereafter, the turbine rotational speed NT of the torque converter 3200, that is, the input shaft rotational speed NI of the automatic transmission 2000, and the synchronous rotational speed calculated by multiplying the output shaft rotational speed NO by the gear ratio of the gear stage after the shift are synchronized. At the timing, the B1 brake 3610 or the B3 brake 3630 is controlled to start to have an engagement force. Eventually, the B1 brake 3610 or the B3 brake 3630 is engaged. When downshifting from the fifth gear to the second gear, the B1 brake 3610 is engaged. When downshifting from the sixth gear to the third gear, the B3 brake 3630 is engaged.

  With reference to FIG. 6, the control mode of each friction engagement element when downshifting from the fifth gear to the second gear will be described.

  After starting the downshift at time T (A), the B3 brake 3630 is released. The engagement pressure of the C2 clutch 3650 is reduced to the target engagement pressure. At the time T (B) when the time T (1) has elapsed after the start of the downshift, the C1 clutch 3640 is engaged. Thereafter, at time T (C) when the time T (2) further elapses, the engagement pressure of the C2 clutch 3650 is gradually reduced at a predetermined decrease rate.

  Thereafter, the turbine rotational speed NT of the torque converter 3200, that is, the input shaft rotational speed NI of the automatic transmission 2000, and the synchronous rotational speed calculated by multiplying the output shaft rotational speed NO by the gear ratio of the gear stage after the shift are synchronized. At the time T (D) when the B1 brake 3610 is operated, control is performed so that the B1 brake 3610 starts to have an engagement force.

  The downshift from the sixth gear to the third gear is performed in the same manner as the downshift from the fifth gear to the second gear. That is, the downshift from the sixth gear to the third gear is the same as the downshift from the fifth gear to the second gear except that the B1 brake 3610 and the B3 brake 3630 are switched. Done in a manner.

  As shown in FIG. 6, the torque reduction unit 8410 starts the turbine rotation speed NT at time T (3) after starting the downshift from the fifth gear to the second gear or from the sixth gear to the third gear. However, the output torque of the engine 1000 is reduced by retarding the ignition timing so as to increase to the synchronous rotational speed in the fourth gear.

  Time T (3) is set to the same or substantially the same time as time T (1). Thus, C1 clutch 3640 can be engaged in accordance with the timing at which turbine rotational speed NT of torque converter 3200 becomes the same rotational speed as the synchronous rotational speed in the gear ratio of the fourth gear.

  The output torque is reduced by a torque down amount calculated based on the output torque TEKL of engine 1000 converted from the intake air amount detected by air flow meter 8002 and the output shaft rotational speed NO of automatic transmission 2000. For example, the output torque of engine 1000 is converted from the intake air amount according to a map using the intake air amount and engine speed NE as parameters. It should be noted that a known general technique may be used as a method for converting the output torque of engine 1000 from the intake air amount, and therefore further detailed description will not be repeated here.

  As shown in FIG. 7, the torque-down amount is set according to a map having output torque TEKL converted from the intake air amount and output shaft rotational speed NO of automatic transmission 2000 as parameters.

  In principle, if the output shaft rotational speed NO is the same, the torque-down amount is set so that the value obtained by subtracting the torque-down amount from the output torque TEKL converted from the intake air amount is the same.

  The engine 1000 is controlled to output a torque obtained by subtracting a set torque-down amount from the output torque TEKL converted from the intake air amount. That is, the output torque of engine 1000 is reduced to a constant torque determined for each output shaft speed NO. When the turbine rotational speed NT rises to the synchronous rotational speed in the fourth gear after the output torque is reduced, the output torque of the engine 1000 is increased.

  The actual change rate detection unit 8420 is configured to detect the turbine rotational speed NT (input shaft detected by the input shaft rotational speed sensor 8022 after the downshift from the fifth gear to the second gear or from the sixth gear to the third gear is started. The actual change rate of the rotational speed NI) is detected.

  The target engagement pressure setting unit 8430 rotates the target engagement pressure by setting the target engagement pressure of the C2 clutch 3650 so as to increase as the change rate ΔNT of the turbine rotation speed NT after the start of the inertia phase increases. It is set according to the inertia of the member 3212.

  More specifically, the target engagement pressure is set as the sum of the basic value and the correction value. The basic value is predetermined by experiment or simulation. The correction value is set according to a map having a change rate ΔNT of the turbine speed NT as a parameter. By setting the correction value according to the change rate ΔNT, the target engagement pressure is set according to the change rate ΔNT. The target engagement pressure is set between an upper limit value and a lower limit value.

  The target engagement pressure is set so that the C2 clutch 3650 has a minimum engagement force that can restrict the rotation of the rotation member 3212. That is, the target engagement pressure is set so that the C2 clutch 3650 has a minimum engagement force necessary to prevent the C2 clutch 3650 from slipping.

  As shown in FIG. 8, torque increase unit 8440 causes engine 1000 output torque to gradually increase at a predetermined rate of increase when the inertia phase starts at time T (E) after the output torque of engine 1000 decreases. To control.

  A control structure of a program executed by ECU 8000 serving as the control device according to the present embodiment will be described with reference to FIGS. 9 and 10. The program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter, step is abbreviated as S) 100, ECU 8000 determines whether or not to downshift from the fifth gear to the second gear or from the sixth gear to the third gear. When downshifting (YES in S100), the process proceeds to S102. If not (NO in S100), this process ends.

  In S102, ECU 8000 starts a downshift from the fifth gear to the second gear or from the sixth gear to the third gear.

  In S104, ECU 8000 releases the friction engagement element different from C2 clutch 3650, that is, B3 brake 3630 or B1 brake 3610. When downshifting from the fifth gear to the second gear, the B3 brake 3630 is released. When downshifting from the sixth gear to the third gear, the B1 brake 3610 is released.

  In S106, ECU 8000 reduces the engagement pressure of C2 clutch 3650 to the basic value of the target engagement pressure described above. That is, the basic value is set to the target engagement pressure.

  In S108, ECU 8000 detects change rate ΔNT of turbine rotational speed NT (input shaft rotational speed NI) detected by input shaft rotational speed sensor 8022.

  At S110, ECU 8000 sets a target engagement pressure correction value based on rate of change ΔNT of turbine speed NT.

  In S112, EUC 8000 determines whether or not the sum of the basic value of the target engagement pressure and the correction value is larger than the lower limit value and smaller than the upper limit value. If the sum of the basic value of the target engagement pressure and the correction value is larger than the lower limit value and smaller than the upper limit value (YES in S112), the process proceeds to S114. If not (NO in S112), the process proceeds to S116.

  In S114, ECU 8000 sets a value obtained by adding the correction value to the basic value of the target engagement pressure as the target engagement pressure. In S116, ECU 8000 performs control so that the engagement pressure of C2 clutch 3650 becomes the target engagement pressure.

  In S118, ECU 8000 determines whether or not C1 clutch 3640 is in a released state. If C1 clutch 3640 is disengaged (YES in S118), the process proceeds to S120. If not (NO in S118), the process proceeds to S124.

  In S120, ECU 8000 determines whether time T (1) has elapsed after the start of the downshift. When time T (1) has elapsed (YES in S120), the process proceeds to S122. If not (NO in S120), the process returns to S108. In S122, ECU 8000 brings C1 clutch 3640 into an engaged state.

  In S124, ECU 8000 determines whether or not time T (2) has elapsed since C1 clutch 3640 was engaged. When time T (2) has elapsed (YES in S124), the process proceeds to S126. If not (NO in S124), the process returns to S108. In S126, ECU 8000 gradually decreases the engagement pressure of C2 clutch 3650 at a predetermined decrease rate.

  In S128, ECU 8000 is engaged at the timing at which turbine rotational speed NT, that is, input shaft rotational speed NI, is synchronized with the synchronous rotational speed calculated by multiplying output shaft rotational speed NO by the gear ratio of the gear stage after the shift. A frictional engagement element different from the C1 clutch 3640, that is, the B1 brake 3610 or the B3 brake 3630 is controlled so as to start having a resultant force. When downshifting from the fifth gear to the second gear, the B1 brake 3610 is finally brought into an engaged state. When downshifting from the sixth gear to the third gear, the B3 brake 3630 is finally engaged.

  The operation of ECU 8000 serving as the control device according to the present embodiment based on the structure and flowchart as described above will be described.

  For example, if the accelerator opening is greatly increased by the driver's accelerator operation, it is determined that the gear shifts from the fifth gear to the second gear or from the sixth gear to the third gear (YES in S100). Therefore, a downshift from the fifth gear to the second gear or from the sixth gear to the third gear is started (S102).

  In the following description, it is assumed that the downshift is performed from the sixth gear to the third gear. When the downshift is started, the B1 brake 3610, which is a friction engagement element different from the C2 clutch 3650, is released (S104). The engagement pressure of the C2 clutch 3650 is reduced to the basic value of the target engagement pressure (S106).

  Thereby, one of the two friction engagement elements forming the gear stage before the shift can be released, and only the other can have an engagement force. By releasing one of the friction engagement elements, the shift can be started quickly. Therefore, compared with the case where the state of the other friction engagement element is controlled according to the state of one of the two friction engagement elements released by the shift, the start of the shift is made earlier. Can do.

  Thereafter, a change rate ΔNT of the turbine rotational speed NT detected by the input shaft rotational speed sensor 8022 is detected (S108). Based on the rate of change ΔNT of the turbine speed NT, a correction value for the target engagement pressure is set (S110).

  If the sum of the basic value of the target engagement pressure and the correction value is larger than the lower limit value and smaller than the upper limit value (YES in S112), a value obtained by adding the correction value to the basic value is set as the target engagement pressure. (S114). Control is performed so that the engagement pressure of the C2 clutch 3650 becomes a newly set target engagement pressure (S116).

  As described above, the target engagement pressure of the C2 clutch 3650 is set so that the C2 clutch 3650 has a minimum engagement force that can restrict the rotation of the rotation member 3212. Therefore, it is possible to regulate the rotational speed of the rotating member 3212, that is, the input shaft rotational speed of the automatic transmission 2000 so as not to be excessive.

  If C1 clutch 3640 is in the disengaged state (YES in S118), when time T (1) has elapsed after the start of the downshift (YES in S120), C1 clutch 3640 is engaged (S122). . C1 clutch 3640 is engaged in accordance with the timing at which turbine rotational speed NT of torque converter 3200 reaches the same rotational speed as the synchronous rotational speed in the gear ratio of the fourth gear. Thereby, the shock that may occur when the C1 clutch 3640 is engaged can be reduced.

  When time T (2) elapses after C1 clutch 3640 is engaged (YES in S124), the engagement pressure of C2 clutch 3650 is gradually reduced at a predetermined reduction rate (S126).

  As described above, the target engagement pressure of the C2 clutch 3650 is set so that the C2 clutch 3650 has a minimum engagement force that can restrict the rotation of the rotation member 3212. Therefore, the rotational speed of rotating member 3212, that is, the input shaft rotational speed of automatic transmission 2000, can be prevented from being excessive, and C2 clutch 3650 can be quickly released.

  Further, thereafter, the turbine rotational speed NT, that is, the input shaft rotational speed NI, starts to have an engagement force at the timing when the synchronous rotational speed calculated by multiplying the output shaft rotational speed NO by the gear ratio of the third gear is synchronized. Thus, the B3 brake 3630 is controlled (S128).

  As described above, according to the ECU that is the control device according to the present embodiment, the C1 clutch and the B1 brake are engaged from the fifth gear that is formed by engaging the B3 brake and the C2 clutch. When downshifting to the second gear stage formed by the above, the B3 brake is released before the C1 clutch and the B1 brake are engaged, and the C2 clutch is controlled to have an engaging force. When downshifting from the 6th gear stage formed by engaging the B1 brake and the C2 clutch to the third gear stage formed by engaging the C1 clutch and the B3 brake, the C1 clutch and the B3 brake are Prior to engagement, the B1 brake is released and the C2 clutch is controlled to have engagement force. Thereby, one of the two friction engagement elements forming the gear stage before the shift can be released, and only the other can have an engagement force. By releasing one of the friction engagement elements, the shift can be started quickly. Therefore, compared with the case where the state of the other friction engagement element is controlled according to the state of one of the two friction engagement elements released by the shift, the start of the shift is made earlier. Can do. As a result, a speed change can be performed promptly.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  In the present embodiment, the downshift from the fifth gear to the second gear or from the sixth gear to the third gear has been described. However, the combination of shifts is not limited to these.

  1000 engine, 2000 automatic transmission, 3000 planetary gear unit, 3200 torque converter, 3212 rotating member, 3610 B1 brake, 3620 B2 brake, 3630 B3 brake, 3640 C1 clutch, 3650 C2 clutch, 4000 hydraulic circuit, 4210 SL1 linear solenoid, 4220 SL2 Linear solenoid, 4230 SL3 linear solenoid, 4240 SL4 linear solenoid, 8000 ECU, 8002 Air flow meter, 8004 Shift lever, 8006 Position switch, 8008 Accelerator pedal, 8010 Accelerator opening sensor, 8012 Brake pedal, 8014 Tread force sensor, 8016 Electronic throttle valve , 8018 Throttle opening Sensor, 8020 engine speed sensor, 8022 input shaft speed sensor, 8024 output shaft speed sensor, 8026 oil temperature sensor, 8100 engine ECU, 8200 ECT_ECU, 8300 ROM, 8400 shift judgment section, 8401 first control section, 8402 2 control unit, 8403 third control unit, 8410 torque reduction unit, 8420 actual change rate detection unit, 8430 target engagement pressure setting unit, 8440 torque increase unit.

Claims (6)

A first gear stage is formed by engaging the first engaging element and the second engaging element, and the second gear is formed by engaging the second engaging element and the third engaging element. An automatic transmission in which a third gear stage is formed by engaging the third engagement element and the fourth engagement element, and an engine coupled to the automatic transmission A power train control device including:
The fourth engagement element before engaging the first engagement element and the second engagement element when performing a shift from the third gear stage to the first gear stage. And the third engagement element is controlled so as to have an engagement force, and the torque of the engine is reduced when shifting from the third gear stage to the first gear stage is started. The control apparatus of a power train provided with the control means.   The control means starts releasing the fourth engagement element and starts reducing the torque of the engine when starting a shift from the third gear stage to the first gear stage. The power train control device according to claim 1.   3. The power train control device according to claim 1, wherein the control means temporarily reduces the torque of the engine when shifting from the third gear stage to the first gear stage is started. 4. .   The power train control device according to claim 3, wherein the control means temporarily reduces the torque of the engine and then makes the torque of the engine constant.   5. The power train according to claim 4, wherein the control means reduces the engine torque so that the output engine torque is the same when the output shaft speed of the automatic transmission is the same. 6. Control device. A first gear stage is formed by engaging the first engaging element and the second engaging element, and the second gear is formed by engaging the second engaging element and the third engaging element. An automatic transmission in which a third gear stage is formed by engaging the third engagement element and the fourth engagement element, and an engine coupled to the automatic transmission A power train control method including:
The fourth engagement element before engaging the first engagement element and the second engagement element when performing a shift from the third gear stage to the first gear stage. And the third engagement element is controlled to have an engagement force, and the torque of the engine is reduced when shifting from the third gear stage to the first gear stage is started. A method for controlling a power train.

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