JP2007170638A - Automatic transmission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly execute shift control when a target shift stage is newly set before finishing the change-over control of a shift stage and the change-over control of the shift stage is continuously performed. <P>SOLUTION: This automatic transmission control device comprises a first friction element to be fastened in a first shift stage, released in a second shift stage after first shift, and fastened in a third shift stage after second shift, a second friction element to be released in the first shift stage, fastened in the second shift stage, and fastened in the third shift stage, and a third friction element to be fastened in the first shift stage, fastened in the second shift stage, and released in the third shift stage. In the case that a target shift stage is changed from the second shift stage to the third shift stage after detecting the start of the inertia phase of the first shift, it starts the second shift while executing the first shift and it selects as a hydraulic pressure command value for the first friction element, greater one of a hydraulic pressure command value in the first shift and a hydraulic pressure command value in the second shift. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control device for an automatic transmission mounted on a vehicle, and more particularly to a control device for an automatic transmission suitable for use in a multi-stage transmission having five or more gear stages.

  In recent years, the number of automatic transmissions has increased, and the number of friction elements such as clutches and brakes has increased in accordance with the number of shift stages. With such an increase in the number of shift stages, the intervals between shift lines in the shift map become very close, and a shift is likely to occur due to a slight change in travel conditions (for example, throttle opening). That is, the shift frequency increases, and the target shift stage is likely to change during the shift.

  Therefore, for example, a control device described in Patent Document 1 is known as a conventional technique when it is determined to change the target gear position during such a shift. This means that if the target shift stage changes due to a change in running conditions (for example, throttle opening) from the shift determination to the start of the actual shift, that is, the inertia phase start, the change of the target shift stage is permitted and the inertia phase starts. After that, the change of the target shift stage is prohibited and the shift during the shift is completed.

  In addition, when the target shift stage is changed (shift determination) after the inertia phase is started (this is called multiple shift), in order to shorten the shift time to the final target shift stage, especially in the shift that is currently in progress. It is described that the friction element in the released state starts to be loosened (precharge) simultaneously with the shift determination and waits for the engagement of the friction element being engaged in the current shift.

Specifically, even if the shift to the third speed is determined during the 1 → 2 shift, the 1 → 3 shift is performed before the inertia phase, but if the inertia phase has started, 1 → 2 It is described that a shift is performed and then a 2 → 3 shift is executed.
JP-A-6-346959

By the way, in the technique disclosed in Patent Document 1, when a shift to another shift stage is determined during the first shift (when the target shift stage changes, that is, when multiple shifts are executed), the inertia phase Since the next shift is started after the completion of the shift, there is a problem that it takes time to complete the shift to the final target shift stage (the changed target shift stage).
Therefore, it is conceivable that the next shift is started simultaneously with the change of the target shift stage. However, if the shift lines are densely provided as described above, the target shift stage is further changed after the target shift stage is changed once. If there is a possibility that the change will be made and the rattling of the friction element on the engagement side starts as soon as the shift is judged, the shift that started with the change of the target shift stage may be stopped and another shift may be performed. The content becomes very complicated, and it is difficult to continuously perform shifting without generating a shift shock.

  Further, in the above case, the first friction element released in the first shift is engaged in the second shift, the second friction element released in the first shift is engaged in the second shift, In the first shift, the third friction element that is engaged is released continuously in the second shift, but in the control device described in the above-mentioned document 2, the engagement is performed after the backlash is completed. In order to start the release of the finished friction element, it was not sufficient from the viewpoint of shortening the shift time.

  In addition, the frictional elements in the engagement transition start to be released when the backlash is completed, and the initial pressure is a value obtained by adding a correction for the change in the throttle opening to the turbine torque at the start of the 3 → 4 shift. However, considering the fact that it is difficult to accurately estimate the input torque in the transient state, and that the hydraulic pressure becomes discontinuous because the hydraulic pressure during the fastening transition is reduced at a stretch, no shift shock is generated. It was difficult to perform control continuously.

  The present invention has been devised in view of such problems, and when there is a change from the first shift speed to the second shift speed when the target shift speed is changed to the third shift speed (multiple shift speed). The purpose is to prevent the occurrence of a shift shock while shortening the shift time to the final target shift stage.

  Therefore, the control device for an automatic transmission according to the present invention is engaged at the first gear, released at the second gear achieved by the first gear, and engaged at the third gear achieved by the second gear. A first friction element that is disengaged at the first gear, fastened at the second gear, fastened at the third gear, fastened at the first gear, and A third friction element that is engaged at the second shift stage and is released at the third shift stage; a target shift stage determining means that determines a target shift stage based on driving conditions; and the first friction element at the first shift. A first shift control means for issuing a hydraulic pressure command for releasing and a hydraulic pressure command for fastening the second friction element; and for giving a hydraulic pressure command for fastening the first friction element during the second shift and for the third friction. 2nd gearshift that gives hydraulic command to release element Means, an inertia phase start detecting means for detecting the start of an inertia phase, and after the start of the inertia phase is detected by the inertia phase detection start means when the first shift is executed, the target shift speed is changed from the second shift speed. When the gear shifts to the third gear, the first predetermined gear ratio before reaching the gear ratio at which the inertia phase of the first gear shift ends or a parameter corresponding to the first predetermined gear ratio is reached. And a third shift control means for starting the second shift while executing the first shift, and the third shift control means includes a hydraulic pressure command for the first friction element after the second shift is started. As a value, the hydraulic pressure command value from the first shift control means and the hydraulic pressure command value from the second shift control means are compared, and the larger value is selected and output to the first friction element. It is characterized in that (claim 1).

Further, the third shift control means, when the third shift speed is set as the target shift speed by the target shift speed determination means after the first predetermined gear ratio is reached, Is preferably executed immediately (Claim 2).
The first and second shift control means is a control means for controlling a downshift, and the first shift control means corresponds to a second predetermined gear ratio or the second predetermined gear ratio. When the parameter is reached, a hydraulic pressure command value is output so that the hydraulic pressure of the first friction element is reduced to zero pressure at a predetermined gradient, and the third shift control means is configured to output the first friction element by the first shift control means. It is preferable to provide an end timing correction means for correcting the hydraulic pressure command value so that the release timing up to zero pressure is advanced.

  Further, the first and second shift control means are control means for controlling an upshift, and the first shift control means is configured to control the first friction element based on a gear ratio or a parameter corresponding thereto. A command to release the hydraulic pressure to the zero pressure with a third predetermined gradient before the end of the first shift is output, and the third shift control means prohibits the release of the first friction element to the zero pressure, It is preferable to provide an end timing correction means for correcting a hydraulic pressure command value so that the hydraulic pressure of the first friction element is maintained at a hydraulic pressure equivalent to the completion of the piston stroke.

The second speed change control means outputs a high pressure hydraulic pressure command value when the first friction element is engaged, and then executes precharge control for promoting the piston stroke by holding at a low pressure. Preferably, the friction element control unit prohibits the precharge control by the second shift control means.
In addition, a piston stroke determination unit that determines completion of the piston stroke of the first friction element is provided, and the second shift control unit is configured to switch a hydraulic pressure command value based on a determination result of the piston stroke determination unit, Preferably, the third shift control means prohibits switching of the hydraulic pressure command value based on the determination result of the piston stroke determination means by the second shift control means.

  Further, the second shift control means outputs a hydraulic pressure command value so that the second shift control means decreases the hydraulic value of the third friction element in a step-like manner to the second hydraulic pressure value simultaneously with the start of the second shift. In addition, when the ratio of the friction elements is defined as the ratio of the torque that each friction element bears in each shift stage when the input torque is 1, the third shift control means When the sharing ratio of the third friction element is smaller in the second shift stage than the sharing ratio in the first shift stage, the second hydraulic pressure value is set to the sharing ratio in the first shift stage and the second shift stage. It is preferable to correct based on the ratio with the sharing ratio in the stage (claim 7).

The end timing correction means corrects the first predetermined gradient according to a vehicle speed or / and an input torque when a parameter corresponding to the second predetermined gear ratio or the second predetermined gear ratio is reached. Then, it is preferable that the first predetermined gradient is corrected so as to increase as the vehicle speed increases or the input torque increases.
Further, the end timing correction means corrects the second predetermined gear ratio or a parameter corresponding to the second predetermined gear ratio according to the vehicle speed or / and the input torque, and as the vehicle speed increases, It is preferable that the second predetermined gear ratio or the parameter corresponding to the second predetermined gear ratio is corrected to the state before the start of the first shift as the input torque increases. (Claim 9)
The third shift control means includes start timing correction means for correcting the first predetermined gear ratio or the predetermined parameter for starting the second shift based on vehicle speed or / and torque, and the start timing correction means. Is corrected so that the difference between the first predetermined gear ratio or the predetermined parameter and the gear ratio at which the inertia phase ends or a parameter corresponding thereto increases as the vehicle speed decreases, and the input torque to the transmission It is preferable to correct the difference so that the difference is larger.

  The control device for an automatic transmission according to the present invention is engaged at a first gear, released at a second gear achieved by the first gear, and fastened at a third gear achieved by the second gear. A friction element, a second friction element that is disengaged at the first speed, is engaged at the second speed, and is engaged at the third speed, and is engaged at the first speed, and the second speed is Is engaged, and is released at the third shift speed, target shift speed determining means for determining the target shift speed based on driving conditions, and when the first shift is performed, the target shift speed is the first shift speed. When changing from the second shift stage to the third shift stage, the first to third friction elements are provided with a shift control means for starting the second shift before the end of the first shift. When the hydraulic pressure command value from the shift control means increases, The shift control means is configured to be released when the hydraulic pressure command value is decreased. When the second shift is started before the end of the first shift, the shift control unit is configured to apply to the first friction element in the first shift. The hydraulic pressure command value is compared with the hydraulic pressure command value for the first friction element in the second shift, and the larger one is selected and output to the first friction element (claim 11).

According to the control apparatus for an automatic transmission of the present invention, even during multiple shifts, the shift data is basically obtained by performing the shift control using the data of the first shift control means and the second shift control means. Can be minimized.
Further, since the second shift is started before the end of the first shift, the time to reach the final target shift stage can be shortened without significantly reducing the hydraulic pressure of the first friction element. That is, the hydraulic pressure of the first friction element is set to the select high after the timing at which the shifts overlap, so that the hydraulic pressure of the first friction element is continuously connected, and two successive shifts can be performed quickly and quickly. This can be performed smoothly, and the occurrence of shift shock can also be suppressed.

Further, since the second shift control is started based on the target shift speed at the time when the first predetermined gear ratio is reached, even if the target shift speed is changed again, the final target shift speed is not complicated. Smooth shifting can be performed. (Claims 1 and 11)
In addition, when the change of the target shift stage is determined in the first shift and the second shift, the second shift is performed before the end of the first shift, so that the time during which the gear ratio stagnates in the second shift stage can be shortened. As a result, the time required to reach the third shift speed, which is the final target shift speed, can be shortened. (Claim 2)
Further, at the time of downshift of the normal gear shift, the timing (removal timing) of decreasing the hydraulic characteristic of the second friction element in the first gear shift toward zero pressure is relatively so as to smooth the torque fluctuation at the end of the gear shift. Since the hydraulic pressure is set to a slow timing and is lowered at a relatively slow gradient, the hydraulic pressure of the second friction element becomes excessive even if the second shift start command is issued during the first shift. However, in the present invention, the interlocking is performed by making correction so as to advance the hydraulic pressure lowering timing as compared with the case where the single first shift is performed. And stagnation of the gear ratio can be prevented. (Claim 3)
Further, at the time of upshifting, it is prohibited to release the hydraulic pressure of the first friction element to zero pressure before the end of shifting, and the hydraulic pressure of the first friction element is maintained at a hydraulic pressure (release pressure) equivalent to the completion of the piston stroke. By correcting the command value, the stagnation of the gear ratio at the second gear can be prevented. That is, when it is determined that the piston stroke of the second friction element is completed as in the normal first shift, if the hydraulic pressure of the first friction element is reduced to zero pressure, the hydraulic pressure can be released before the start of the second shift. Therefore, the piston stroke of the first friction element must be made again at the start of the second shift, the actual start of the second shift is delayed, the gear ratio is stagnated at the second shift stage, and the driver feels uncomfortable. There is a possibility that the stagnation of the gear ratio can be prevented by maintaining the hydraulic pressure of the first friction element at the release pressure. (Claim 4)
In addition, during multiple shifts, precharge control at the start of the second shift is prohibited, so that shift shock can be prevented. That is, although the hydraulic pressure of the first friction element released by the first shift is low, the piston is in a stroked state. At this time, if precharging is performed in the same way as during normal operation at the second shift, the first friction element The command oil pressure for the second shift with respect to the pressure becomes too high, and a shift shock due to the sudden engagement of the first friction element occurs. On the other hand, by prohibiting the precharge, the sudden engagement of the first friction element can be suppressed, so that a shift shock can be prevented. (Claim 5)
Further, during multiple shifts, the third shift control means prohibits switching of the hydraulic command value based on the determination result of the piston stroke determination means by the second shift control means during the second shift (that is, the information from the piston stroke determination means is used). Cancel), a shift shock can be prevented.

That is, when the start timing of the hydraulic switching control of the first friction element is determined based on the result of the hydraulic switch as in the normal second shift, the first friction element being released in the first shift is Since the piston stroke is completed at the start of the second shift, a shift command to the switching control is output simultaneously with the start of the second shift, and a shift shock may occur. By prohibiting switching of the hydraulic pressure command value based on the determination result of the stroke determination means, such a shift shock can be prevented. (Claim 6)
In addition, when the sharing ratio of the second gear is smaller than the sharing ratio of the first gear of the third friction element, if the shift control is performed based on the data of the normal second gear during the first gear, Decreasing the hydraulic pressure of the third friction element to the equivalent of the fourth speed sharing ratio before the determination of the second gear speed (for example, fourth speed), that is, in the state where the first gear ratio (for example, sixth speed) is required. Become. In other words, the capacity of the friction element will be insufficient by the share ratio of the first gear stage / the share ratio of the second gear stage, and the gear ratio may be blown up due to the lack of capacity, but it is appropriate depending on the share ratio Further, by correcting the second hydraulic pressure value, it is possible to suppress the blow-up. (Claim 7)
Further, since the hydraulic pressure of the first friction element increases as the input torque increases, it takes time to release, and it is possible to suppress stagnation, interlock, and blow-up at an interlock or intermediate gear. (Claim 8)
Further, as the vehicle speed increases and the input torque increases, the parameter corresponding to the second predetermined gear ratio or the second predetermined gear ratio is set to the high speed side when downshifting, and to the constant speed stage when upshifting. By correcting to the side, this control can be performed appropriately according to the vehicle speed and input torque, and stagnation and interlock at the intermediate gear stage can be reliably prevented regardless of the driving conditions of the vehicle. . (Claim 9)
By the way, when the data of the second speed change control means is used as much as possible, the timing for starting the second speed change control during execution of the first speed change control is as much as taking into account the response delay of the actual oil pressure with respect to the command oil pressure. It is necessary to set early. In addition, the response of the actual hydraulic pressure is constant as long as the viscosity of the hydraulic oil does not change. Therefore, a constant (or fixed) gear ratio before reaching the gear ratio at the end of the inertia phase is used, and when this constant gear ratio is reached, the second shift is started to cancel the response delay of the actual hydraulic pressure. That's fine. However, since the change rate of the gear ratio varies depending on the torque and the vehicle speed, the time to reach the gear ratio at the end of the inertia phase changes depending on the torque and the vehicle speed. As a result, when the second shift control is started at a timing when a certain gear ratio is reached, there is a possibility that stagnation, interlock, and blow-up may occur at the intermediate shift speed depending on the torque and the vehicle speed. On the other hand, in the present invention, as the vehicle speed decreases, the difference between the first predetermined gear ratio (the gear ratio at which the second shift is started) and the gear ratio at which the inertia phase ends is corrected and the transmission is changed. By correcting so that the difference increases as the input torque increases, it is possible to correct the start timing of the second shift to an appropriate timing, and to prevent stagnation at the intermediate shift stage, interlock, blow-up, etc. Can do. (Claim 10)

Hereinafter, a control apparatus for an automatic transmission according to an embodiment of the present invention will be described with reference to the drawings.
1. Configuration of Automatic Transmission FIG. 1 is a skeleton diagram showing a configuration of an automatic transmission 1 of 6 forward speeds and 1 reverse speed to which the present invention is applied. As shown in the figure, the power of the engine 2 input to the torque converter 3 is input to the carrier 5 of the double pinion type planetary gear mechanism (first planetary gear mechanism) 4 via the rotation shaft S1. Yes.

  Here, the double pinion type planetary gear mechanism 4 includes a sun gear 7 fixed to the transmission case 6, an inner diameter side pinion gear 8 that meshes with the sun gear 7, and an outer diameter side pinion gear 9 that meshes with the inner diameter side pinion gear 8. And a ring gear 10 that meshes with the outer diameter side pinion gear 9 and is coaxial with the sun gear, and an inner diameter side pinion gear 8 and a carrier 5 that pivotally supports the outer diameter side pinion gear 9.

The ring gear 10 is connected to a rotation shaft S2 that covers the outer periphery of the rotation shaft S1 and extends toward the engine 2 through the inner diameter side of an output gear 17 described later.
The carrier 5 is connected to a rotating shaft S3 that covers the outer periphery of the rotating shaft S2 and extends toward the engine 2 via a high clutch H / C.
The end of the rotary shaft S3 opposite to the side where the high clutch H / C is connected is connected to a carrier 16 that supports the pinion gear 13 of the single pinion type planetary gear mechanism (second planetary gear mechanism) 11. Yes. The carrier 16 is connected to the transmission case 6 via a low & reverse brake L & R / B and a low one-way clutch LOW / OWC arranged in parallel.

As a result, the carrier 16 is rotatably supported on one side with respect to the transmission case 6, and the rotation can be regulated (fixed) and regulated.
The single pinion type planetary gear mechanism 11 meshes with the second sun gear 14 with the pinion gear 13 disposed on the engine 2 side and the first sun gear 12 disposed on the side opposite to the engine 2 side and with the ring gear 15. It is configured as follows.

The first sun gear 12 extends in a direction opposite to the engine 2 and is connected to a rotation shaft S4 that covers the outer periphery of the rotation shaft S3. The rotation shaft S4 is connected to the transmission case 6 via a 2-6 brake 2-6 / B. It is connected. Thus, the rotation shaft S4 is configured to be fixed and unfixable with respect to the transmission case 6 via the 2-6 brake 2-6 / B.
The second sun gear 14 passes through the inner diameter side of the output gear 17 and extends to the engine 2 side, and is connected to a rotation shaft S5 that covers the outer periphery of the rotation shaft S2. The rotation shaft S5 is connected via a 3-5 reverse clutch 3-5R / C. Are connected to the rotary shaft S2 and are connected to a ring gear 21 of a single pinion type planetary gear mechanism (third planetary gear mechanism) 18 through a low clutch LOW / C.

  Here, the single pinion type planetary gear mechanism 18 is disposed between the output gear 17 and the 3-5 reverse clutch 3-5R / C on the outer peripheral side of the rotation shaft S5. The single pinion planetary gear mechanism 18 meshes with the sun gear 19 connected to the rotation shaft S5, the ring gear 21 disposed on the outer diameter side of the sun gear 19, the sun gear 19 and the ring gear 21, and is supported by the carrier 22. The pinion gear 20 is configured.

The carrier 22 is connected to a rotation shaft S6 that covers the outer peripheral side of the rotation shaft S5 and passes through the inner diameter side of the output gear 17 and extends to the second planetary gear mechanism 11. The rotation shaft S6 is connected to the ring gear 15 of the second planetary gear mechanism 11.
Further, a bearing support portion 30 is disposed between the second planetary gear mechanism 11 and the third planetary gear mechanism 18. The bearing support portion 30 is formed integrally with the transmission case 6 via a partition-like member, and has a cylindrical bearing support portion 31 extending along the rotation axis S6.

A bearing 32 is fitted on the outer periphery of the bearing support portion 31, and the output gear 17 connected to the ring gear 15 is in contact with the outer peripheral portion (outer race) of the bearing 32.
The inner diameter side of the bearing support portion 31 has a multilayer structure in which the rotation shafts S1, S2, S5, and S6 are overlapped and arranged coaxially.
In the automatic transmission 1, automatic shift control of 6 forward speeds is performed based on the driving point determined from the vehicle speed and the throttle opening at the D range position and a shift schedule (shift map), and from the D range position to the R range position. The first reverse gear shift control is performed by the selection operation to.

  In this case, the combination of high clutch H / C, 2-6 brake 2-6 / B, low & reverse brake L & R / B, low clutch LOW / C and 3-5 reverse clutch 3-5R / C The output rotational speed of the engine 2 is converted into a desired rotational speed, and is transmitted from the output gear 17 to the driving wheel of the vehicle (not shown) via the counter shaft 23 and the differential gear 24.

The operating state of each friction element in this shift control is shown in FIG. In FIG. 2, “○” indicates fastening, no marking indicates “release”, ○ indicates “×” indicates fastening, but it operates when the engine is braked, and “smugging” indicates that the engine is mechanically engaged (rotation restricted) when the engine is driven. Indicates.
The first speed (1ST) is achieved by engaging the low clutch LOW / C and engaging the low & reverse brake L & R / B. In this case, the rotation decelerated from the input shaft (rotation shaft S1) via the first planetary gear mechanism 11 is transmitted from the rotation shaft S2 via the low clutch LOW / C and the ring gear 21 of the second planetary gear mechanism 18. The ring gear 15 is decelerated and rotated while receiving a reaction force from the carrier 16 that is input to the carrier 22 and is fastened to the transmission case 6 by the engagement of the low one-way clutch LOW / OWC. Is output. During engine braking, the low & reverse brake L & R / B receives reaction force instead of the idling low one-way clutch LOW / OWC.

  The second speed (2ND) is obtained by engaging the low clutch LOW / C and the 2-6 brake 2-6 / B. In the second speed, the first sun gear 12 and the pinion gear 13 are fixed to the transmission case 6 by engaging the 2-6 brake 2-6 / B. Further, since the pinion gear 13 and the second sun gear 14 mesh with each other, the rotation shaft S5 connected to the second sun gear 14 is fixed to the transmission case 6.

The third speed (3RD) is obtained by engaging the 3-5 reverse clutch 3-5R / C and the low clutch LOW / C, and the fourth speed (4TH) is the high clutch H / C and the low clutch LOW / C. It is obtained by fastening C. The fifth speed (5TH) is obtained by engaging the high clutch H / C and the 3-5 reverse clutch 3-5R / C.
The sixth speed (6TH) is obtained by engaging the high clutch H / C and the 2-6 brake 2-6 / B. At the sixth speed, the rotation shaft S5 is fixed by engaging the 2-6 brake 2-6 / B as in the second speed. Further, the reverse is obtained by engaging the 3-5 reverse clutch 3-5R / C and the low and reverse brake L & R / B.
2. 3. Description of Hydraulic Circuit and Electronic Shift Control System Next, the hydraulic circuit and electronic shift control system for achieving the above-described shift control will be described with reference to FIG. 3. In FIG. 3, 101 is an engagement piston chamber of the low clutch LOW / C, 102 is the engagement piston chamber of the high clutch H / C, 103 is the engagement piston chamber of the 2-6 brake 2-6 / B, 104 is the engagement piston chamber of the 3-5 reverse clutch 3-5R / C, and 105 is low and reverse This is the engagement piston chamber of the brake L & R / B.

The low clutch LOW / C, high clutch H / C, 2-6 brake 2-6 / B, 3-5 reverse clutch 3-5R / C, and low & reverse brake L & R / B are respectively connected to the engagement piston chambers 101 to 105. It is fastened by supplying a fastening pressure which is a D range pressure or an R range pressure, and is released by releasing this fastening pressure.
The D range pressure is a line pressure through a manual valve and is generated only when the D range is selected. The R range pressure is a line pressure through a manual valve, which is generated only when the R range is selected, and is connected to the drain port outside the R range, and no pressure reduction occurs.

  In FIG. 3, 106 is a first hydraulic control valve that controls the engagement pressure to the low clutch LOW / C, 107 is a second hydraulic control valve that controls the engagement pressure to the high clutch H / C, and 108 is a 2-6 brake. 3rd hydraulic control valve that controls the engagement pressure to 2-6 / B, 109 is the 4th hydraulic control valve that controls the engagement pressure to 3-5 reverse clutch 3-5R / C, 110 is low & reverse brake L & R This is a fifth hydraulic control valve that controls the fastening pressure to / B. The first hydraulic control valve 106 includes a first duty solenoid 106a that creates a shift control pressure using a pilot pressure as a base pressure and a solenoid force, and a low clutch that uses a D range pressure as a base pressure and a shift control pressure and a feedback pressure as an operation signal pressure. And a first pressure regulating valve 106b that regulates the pressure. The first duty solenoid 106a is controlled according to the duty ratio. Specifically, the low clutch pressure is zero when the solenoid is OFF, and the low clutch pressure is increased as the ON duty ratio increases when the solenoid is ON. .

  The second hydraulic control valve 107 includes a second duty solenoid 107a that generates a shift control pressure using a pilot pressure as a base pressure, and a high clutch that uses a D range pressure as a base pressure and a shift control pressure and a feedback pressure as an operation signal pressure. And a second pressure regulating valve 107b that regulates the pressure. The second duty solenoid 107a sets the high clutch pressure to zero when the solenoid is ON (100% ON duty ratio), increases the high clutch pressure as the ON duty ratio decreases, and increases the high clutch pressure to the maximum pressure when the solenoid is OFF. And

  The third hydraulic control valve 108 includes a third duty solenoid 108a for generating a shift control pressure by a solenoid force using a pilot pressure as an original pressure, a 2-duration pressure using a D range pressure as an original pressure, and a shift control pressure and a feedback pressure as an operation signal pressure. And a third pressure regulating valve 108b for regulating 6 brake pressures. The third duty solenoid 108a makes the 2-3 brake pressure zero when the solenoid is OFF, and increases the 2-3 brake pressure as the ON duty ratio increases when the solenoid is ON.

  The fourth hydraulic control valve 109 is a fourth duty solenoid 109a that creates a shift control pressure by a pilot force with a pilot pressure as an original pressure, and a shift control pressure and a feedback pressure with the line pressure as an original pressure when the D range is selected. The 4-5 pressure regulating valve 109b that adjusts the 3-5 reverse clutch pressure as the operation signal pressure and supplies the line pressure as the R range pressure to the 3-5 reverse clutch pressure as it is using the R range pressure as the operation signal pressure when the R range is selected. It is comprised by. The fourth duty solenoid 109a sets the 3-5 reverse clutch pressure to zero when the solenoid is ON (100% ON duty ratio), and increases the 3-5 reverse clutch pressure as the ON duty ratio decreases. 3-5 Make the reverse clutch pressure the maximum pressure.

  The fifth hydraulic control valve 110 includes a fifth duty solenoid 110a that generates a shift control pressure by a solenoid force using a pilot pressure as an original pressure, and a low and reverse operation using a line pressure as an original pressure and a shift control pressure and a feedback pressure as an operation signal pressure. It is comprised by the 5th pressure regulation valve 110b which regulates brake pressure. The fifth duty solenoid 110a makes the low & reverse brake pressure zero when the solenoid is OFF, and increases the low & reverse brake pressure as the ON duty ratio increases when the solenoid is ON.

  In FIG. 3, 111 is a first pressure switch (hydraulic pressure detecting means), 112 is a second pressure switch (hydraulic pressure detecting means), 113 is a third pressure switch (hydraulic pressure detecting means), and 114 is a fourth pressure switch (hydraulic pressure detecting means). ), 115 is a fifth pressure switch (hydraulic pressure detecting means), 116 is a manual valve, 117 is a pilot valve, 118 is a shuttle ball valve, 119 is a line pressure oil passage, 120 is a pilot pressure oil passage, and 121 is a D range pressure oil. Road, 122 is R range pressure oil path, 124 is low clutch pressure oil path, 125 is high clutch pressure oil path, 126 is 2-6 brake pressure oil path, 127 is 3-5 reverse clutch pressure oil path, 128 is low & Reverse brake pressure oil passage.

  That is, the low clutch pressure oil passage 124, the high clutch pressure oil passage 125, the 2-6 brake pressure oil passage 126, the 3-5 reverse clutch pressure oil passage 127, and the low & reverse brake pressure oil passage 128, respectively. Are provided with first to fifth pressure switches 111 to 115 for detecting presence / absence of a fastening pressure by a switch signal (ON with fastening pressure, OFF without fastening pressure).

In FIG. 3, 40 is an A / T control unit (control means), 41 is a vehicle speed sensor, 42 is a throttle sensor (torque signal generation means), 43 is an engine rotation sensor, 44 is a turbine rotation sensor, 45 is an inhibitor switch, 46 Is an oil temperature sensor, which constitutes an electronic transmission control system.
In the A / T control unit 40, the switch signals from the pressure switches 111 to 115 and the signals from the sensors and switches 41 to 46 are input, and these input information and a preset shift control law or Calculation processing is performed based on the fail-safe control law and the like, and calculation is performed on the first duty solenoid 106a, the second duty solenoid 107a, the third duty solenoid 108a, the fourth duty solenoid 109a, and the fifth duty solenoid 110a. A solenoid drive signal according to the processing result is output.

Details of the A / T control unit 40 will be described later.
3. Description of Shift Control Next, shift control at the time of multiple shift, which is a feature of the present invention, will be described together with normal shift control. As already described in the section of the background art, in the multi-stage automatic transmission as described above, since the shift line of the shift map is dense, the frequency with which the target shift stage is changed during the shift increases. It becomes. For example, a situation in which the target shift speed is changed to the fourth speed during the shift control from the sixth speed to the fifth speed (hereinafter, such a shift is referred to as multiple shift) frequently occurs.

  In such a multiple shift, for example, when downshifting, for example, 6th speed → 4th speed → 2nd speed (hereinafter described as 6 → 4 → 2), as shown in the operation diagram of the friction element in FIG. The 2-6 brake 2-6 / B is released at the shift from the first 6th speed (first shift stage) to the 4th speed (second shift stage) (referred to as the first shift or the previous shift). In the shift from the fourth speed (second shift speed) to the second speed (third shift speed) (referred to as the second shift or the next shift), the 2-6 brake 2-6 / B is engaged again.

Therefore, in the multiple shift of 6 → 4 → 2, the 2-6 brake 2-6 / B starts the engagement control when the second shift is started after the release control is once started in the first shift. Thus, the control of release → engagement is continuously performed.
Similarly, the control that the 3-5 reverse clutch 3-5R / C is disengaged → engaged is continuously performed at the time of shifting from 5 → 4 → 3.

On the other hand, in the upshift, the 3-5 reverse clutch 3-5R / C is released → engaged at the time of 3 → 4 → 5 shift.
In this way, the friction element that is engaged at the first speed, released at the second speed achieved by the first speed, and engaged at the third speed achieved by the second speed is referred to as the first friction below. Among the multiple shifts described above, 2-6 brake 2-6 / B at the time of 6 → 4 → 2 shift and 3-5 reverse clutch 3− at the time of 5 → 4 → 3 shift in downshift. 5R / C corresponds to the first friction element.

In the upshift, 3-5 reverse clutch 3-5R / C at the time of 3 → 4 → 5 shift corresponds to the first friction element.
In the following description, the friction element that is released at the first gear and is engaged at both the second and third gears is referred to as a second friction element, and is engaged at both the first and second gears. The friction element released at the third shift speed is called a third friction element.

In this apparatus, hydraulic control is performed on each friction element so that the multiple shift in which the friction element is changed from the release control to the engagement control is completed quickly and smoothly.
3.1 Description of Functional Configuration Hereinafter, shift control of multiple shift, which is a characteristic part of the present invention, will be described. FIG. 4 is a schematic block diagram showing a functional configuration of a main part of the present invention. Further, various sensors and switches 41 to 46, 111 to 115 are connected to the input side of the A / T control unit 40, and the duty solenoids 106a to 110a are connected to the output side.

Further, the A / T control unit 40 is provided with a target shift speed determining means 401, a shift control means 402, an inertia phase start detecting means 406, etc., and performs arithmetic processing based on input information from the various sensors. And output a solenoid drive signal to each of the duty solenoids 106a to 110a.
Among these, the target shift speed determining means 401 has a function of determining the target shift speed based on vehicle driving information such as the driver's accelerator depression amount and vehicle speed, and is stored in the A / T control unit 40 as a shift map. Has been. The inertia phase start detection means 406 calculates the actual transmission gear ratio based on information from the turbine rotation sensor 44 and the like, and detects or determines the start of the inertia phase based on the calculated transmission gear ratio. . The inertia phase start detection means 406 can also detect or determine the end of the inertia phase, and therefore the inertia phase start detection means 406 also functions as an inertia phase end detection means.

  The shift control unit 402 includes a first shift control unit 403, a second shift control unit 404, and a third shift control unit 405. Among these, the first speed change control means 403 issues a hydraulic pressure command so as to release the first friction element and a second friction element so as to release the first friction element at the time of the first speed change. The means 404 issues a hydraulic pressure command for fastening the first friction element at the time of the second shift, and a hydraulic pressure command for releasing the third friction element.

  Here, in these first and second shift control means 403 and 404, a control program (control data) is stored in advance for each shift pattern. With respect to the shift step by one step (the above is referred to as a normal shift), shift control is executed using the control data stored in the first and second shift control means 403 and 404.

If a new target shift stage is set by the first shift control unit 403 before the end of the first shift (the first shift or the previous shift), the third shift unit 405 does not wait for the end of the first shift. The second shift (next shift) by the shift control means 404 is started. Specifically, when the target gear shifts from the second gear to the third gear after the start of the inertia phase is detected by the inertia phase start detector 406 during execution of the first gear, the first Means for optimizing the control by starting the second shift control while executing the shift control and, particularly in the overlap period between the first shift control and the second shift control, achieving consistency of the hydraulic command for each friction element. It is. The third transmission means 405 is provided with a start timing correction means 407 for correcting the timing for starting the second shift and an end timing correction means 408 for correcting the end timing of the first shift.
3.2 Specific Description of Gear Shift Control 3.2.0 Shift Control at Normal Time Before describing gear shift control at the time of multiple gear shift, normal gear shift control which is the premise control will be described below. This normal shift control is a known technique, but will be described in detail below in order to clarify the difference from the multiple shift that is the feature of the present invention. Here, the normal shift control is a shift executed in accordance with a control program (control data) stored in advance in the first and second shift control means 403 and 404 as described above, and is a downshift. If so, the shift control from the nth stage to the (n-1) th stage and the nth stage to the (n-2) th stage, and to the upshift, the shift control from the nth stage to the (n + 1) th stage. Hereinafter, the normal shift control is also referred to as single shift control.
3.2.1 Normal Downshift First, the downshift will be described with reference to FIGS. 5 and 6. FIG. 5 is a time chart for explaining the normal downshift, and FIG. 6 is a flowchart thereof.

Now, the traveling condition fluctuates during traveling at the nth stage (first shift stage), and the target shift stage is set by the shift map (target shift stage determining means) 401 provided in the A / T control unit 40. When set to the (n-1) th stage (second shift stage), a downshift from the nth stage to the (n-1) th stage is started based on a control signal from the first shift control means 403.
When the downshift is started, pre-charge control (backlash control) is executed at the engagement-side friction element as soon as shifting is started (AC11 in FIGS. 5 and 6). This precharge control is executed in order to complete the piston stroke as soon as possible, and a high hydraulic pressure command value that causes a stroke of about 70% of the total piston stroke is output. The hydraulic pressure command value at this time is output as a preset value PA1 + learning amount. (Corresponds to the first half of claim 5 of the claims)
Then, after outputting the hydraulic pressure command value (set value PA1 + learning amount) for a predetermined time T1, the hydraulic pressure command value is once reduced, and after this precharge control, the hydraulic pressure is such that the above-mentioned loose state can be maintained. The hydraulic pressure command value (preset value PA2 + learning amount) is set so as to be a value to prepare for fastening (see steps S101 and S102 in FIG. 6). Note that learning is performed based on the time until the inertia phase and the rate of change.

  After the predetermined time T1 has elapsed, the process shifts to piston stroke control (AC12 in FIG. 5). In this piston stroke control, the hydraulic pressure command value is increased with a predetermined gradient RA1 from the hydraulic pressure command value (PA2 + learning amount) according to the input torque, and the piston stroke of the clutch of the engagement side friction element is controlled. In this case, the predetermined gradient RA1 is set to a value that maintains the oil pressure in the second friction element at a constant value, and is set in consideration of the rise of the actual oil pressure after the end of the piston stroke control, variations in the piston stroke, and the like. (Step S103). In the case of a power-on downshift, the shift control is advanced by a release side friction element described later, and in the case of a power-off downshift, the shift control is advanced by a fastening side friction element. For this reason, the predetermined gradient RA1 is set more gently in the power-on downshift than in the power-off downshift.

  Then, the piston of the engagement side friction element gradually strokes under a constant oil pressure value by such a hydraulic pressure command value, and when the piston stroke ends, the hydraulic switch (piston stroke determination means) of the engagement side friction element is It becomes ON. For this reason, when the hydraulic switch ON is detected, the piston stroke control is terminated, and the process proceeds to the next AC21 (step S104). Note that the timer and gear ratio are monitored as a backup of the hydraulic switch, and even if the hydraulic switch ON is not detected, a predetermined time T2 has elapsed from the start of the piston stroke control, or the gear ratio is the inertia phase start gear ratio GR1. If the predetermined gear ratio GR4 is reached, piston stroke control is terminated.

  On the other hand, in the release side friction element, first, undershoot prevention control (RC11 in FIGS. 5 and 6) is executed. That is, when the downshift is started, in the disengagement side friction element, the hydraulic pressure command value is reduced to a predetermined hydraulic pressure command value (first hydraulic pressure value) TR2 set according to the input torque. At this time, in order to prevent an excessive decrease (undershoot) in the hydraulic pressure, a slightly higher hydraulic pressure command value (+ TR1) is output with respect to the target hydraulic pressure command value TR2 at the start of shifting, and then the hydraulic pressure command value Is gradually reduced to the target hydraulic pressure command value TR2 over a predetermined time T14 (see steps S201 and S202 in FIG. 6).

Note that the hydraulic pressure command value TR2 is a hydraulic pressure that starts the inertia phase during the power-on downshift, and corresponds to a hydraulic pressure that causes the clutch of the disengagement side friction element to slightly slide. Further, this corresponds to a hydraulic pressure at which the clutch of the disengagement side friction element does not slip during the power-off downshift.
Then, when the predetermined time T14 elapses, the process proceeds to pre-replacement holding control (RC11 in FIGS. 5 and 6). In this control, at the time of power-off downshift, the hydraulic pressure TR2 corresponding to the input torque is held until the piston stroke of the engagement-side friction element is completed, and the shift stage is held on the release side (step S203). .

This is because if both the release-side friction element and the engagement-side friction element are released, the neutral state occurs and the rotation blows away. Control is executed.
Further, during the power-on downshift, the clutch slips by holding the hydraulic pressure TR2 corresponding to the input torque. In this case, the gear stage is held by the engagement-side friction element. Then, when the hydraulic switch ON (= piston stroke end) of the engagement side friction element is detected or a preset time T2 + T10 has elapsed, the pre-replacement holding control is ended (step S204).

Now, when the above-described engagement side friction elements AC11 and AC12 and the release side friction element RC11 are completed, the process proceeds to AC21 and RC21, and the switching control is started.
In this switching control, in the disengagement side friction element, when the piston stroke ends during the power-off downshift (hydraulic switch ON or T10 + T2 elapses), the hydraulic pressure is reduced at a predetermined gradient RR2 corresponding to the input torque (step S205). At the time of power-on downshift, in many cases, inertia phase control (RC31) is started before start of changeover control, and there are many cases where there is no changeover control of RC21. Therefore, when the inertia phase does not start, this switching control functions as a backup, and the oil pressure is lowered at the gradient RR2 to promote the start of the inertia phase. When the gear ratio reaches the inertia phase determination gear ratio GR1, the switching control is terminated and the process proceeds to inertia phase control (step S206).

  On the other hand, in the engagement side friction element, the hydraulic pressure command value is increased at a predetermined gradient RA2 set in advance based on the input torque and the vehicle speed (step S105). Here, the gradient RA2 at the time of power-off downshift is set for each input torque and vehicle speed so that the pulling gradient (decreasing gradient of the output shaft torque) is optimum, and the gradient becomes larger as the input torque increases. Is set to Further, at the time of power-on downshift, if the piston stroke is completed, the fastening capacity is not required, so that the minimum gradient is set. When the predetermined gear ratio GR5 is reached, the switching control of the engagement-side friction element is finished, and the process proceeds to the next inertia phase control (step S106).

  When the inertia phase control (AC31, RC31) is entered, in the case of a power-off downshift in the disengagement side friction element, the oil pressure command value is decreased from the oil pressure at the time of inertia phase detection with a predetermined gradient corresponding to the input torque and vehicle speed. In the case of a power-on downshift, the hydraulic pressure command value is increased with a gradient corresponding to the input torque and the vehicle speed, and in the power-on downshift, the shift progress is controlled by the hydraulic pressure of the disengagement side friction element. In particular, by providing a clutch capacity, the drop of the output shaft torque and the progress of the shift are slowed to facilitate synchronization of the engagement side friction element at the n-th gear (step S207). Then, when the gear ratio GR reaches a predetermined gear ratio GR3 close to the n-1 stage gear ratio, the inertia phase control is terminated (step S208).

  In the engagement side friction element, when the inertia phase control is started, the hydraulic pressure is increased at a predetermined gradient RA3 set in advance based on the input torque and the vehicle speed. During the power-off downshift, the gradient becomes gentle so that the shift gradually ends from the middle to the end of the inertia phase. In addition, at the time of power-on downshift, since the fastening capacity is not required, the minimum gradient is set (step S107). When the gear ratio GR reaches the predetermined gear ratio GR6 set before the above-described predetermined gear ratio GR3, the inertia phase control is ended (step S108).

  Thereafter, the engagement side friction element shifts to inertia phase end control (AC41). In this inertia phase end control, the hydraulic pressure is increased over a predetermined time T12 set in advance to a predetermined hydraulic pressure TA14 based on the input torque (steps S109 and S110). Here, the predetermined hydraulic pressure TA14 is a hydraulic pressure that can reliably determine the n-th gear stage, and can prevent a shift shock that occurs due to variations in the detection of the end of the inertia phase.

When the predetermined time T12 elapses, the hydraulic pressure command value (duty) is set to 100%, the maximum hydraulic pressure (MAX pressure) is output, and the shifting of the engagement side friction element is completed.
On the other hand, in the release side fastening element, when the inertia phase control is finished, the diagonal punching chamfering control (RC41) is executed. In this oblique punching chamfering control, when it is determined that the inertia phase has ended, the hydraulic pressure is reduced at a predetermined gradient (first predetermined gradient) RR4 corresponding to the input torque, and the torque fluctuation of the output shaft is suppressed, and the minimum hydraulic pressure (zero hydraulic pressure) is quickly achieved. (Step S209). (Corresponds to the first half of claim 3 of the claims)
Then, when a predetermined time T8 has elapsed since the hydraulic pressure was reduced at the predetermined gradient RR4 in this way, the hydraulic pressure command value (duty) is set to 0% and the minimum hydraulic pressure (MIN pressure = zero hydraulic pressure) is output to release the frictional element. The shifting of is finished.

As described above, the first shift control means 403 executes the downshift of the normal shift.
3.2.2 Downshift at Multiple Shift Next, the shift control at the multiple shift in which the target shift stage is changed during the shift will be specifically described. In the following description, while the target shift speed is set to the 4th speed during the 6th speed travel and the 6 → 4 shift is being executed, the 4 → 2 shift is continuously performed by newly setting the target shift speed to the 2nd speed. An example of a downshift of 6 → 4 → 2 multiple shifts as executed will be described.

  FIG. 8 is a time chart showing the downshift characteristics at the time of multiple shift 6 → 4 → 2, where (a) is the throttle opening TH, (b) is the gear ratio GR of the transmission, and (c) is the shift. Oil pressure command values for friction elements that are sometimes engaged or released [more specifically, oil pressure command values (duty ratios) for the oil pressure control valves of the friction elements (see the first to fifth oil pressure control valves 106 to 110 in FIG. 3)] Each characteristic is shown.

In the downshift of 6 → 4 → 2, 2-6 brake 2-6 / B is released → engaged, so that 2-6 brake 2-6 / B becomes the first friction element. Equivalent to. The low clutch LOW / C corresponds to the second friction element, and the high clutch H / C corresponds to the third friction element.
In the following description, portions different from the normal downshift will be mainly described, and description of the portions described in the above-mentioned “3.2.1 Normal downshift” will be omitted as much as possible.

  Now, the traveling condition fluctuates during traveling at the sixth speed (first gear), and the target gear is set to 4 by the shift map (target gear determining means) 401 provided in the A / T control unit 40. When the speed (second gear) is set, a one-step jump downshift (referred to as the first gear shift or the previous gear shift) from the sixth gear to the fourth gear starts based on the control signal from the first gear shift control means 403. (T1 in FIG. 8).

When the target shift stage changes from the fourth speed (second shift stage) to the second speed (third shift stage) after determining the start of the inertia phase of the first shift, the target shift stage to the second speed is determined (when the shift is determined). ) And a gear ratio (inertia phase end gear ratio) for determining the end of 6 → 4 shift (first shift) and a first predetermined gear ratio (second shift start gear ratio or forward) before GR3 GR3A (also referred to as a gear ratio) is compared, and when the gear ratio reaches the second shift start gear ratio GR3A and a shift determination to the third shift stage is made, the third shift control means 405 The start of the second shift is instructed, and the second shift by the second shift control means 404 is immediately executed. (Corresponding to claim 2 of the claims)
Further, if the gear ratio at the time of changing the target shift stage is before the second shift start gear ratio GR3A, the third shift control means 405 does not immediately start the 4 → 2 shift (second shift). Thus, the start of the second shift control is prohibited. This is because if the second shift is executed during the inertia phase, an interlock may be generated. In order to avoid such an interlock, the start of the second shift is prohibited during the inertia phase.

After that, when the gear ratio reaches the second shift start gear ratio GR3A, the prohibition of the second shift is canceled, and the third shift control unit 405 shifts the second shift control unit 404 from 4 → 2 shift (second The start of shifting is instructed (see t2 in FIG. 8).
Here, when the second shift start gear ratio GR3A before the end of the inertia phase is reached, the second shift is started without waiting for the end of the first shift mainly for the following reason. That is, if the second shift is started after waiting for the end of the first shift, the delay in the hydraulic response at the start of the second shift causes a delay between the end of the first shift and the start of the second shift. There is a possibility that the stagnation time occurs, and as a result, the shift time increases.

  Therefore, in the present device, when the target shift speed is changed to the third shift speed after the start of the inertia phase, the second shift speed is changed when the gear ratio becomes the second shift start gear ratio GR3A before the inertia phase end gear ratio GR3. Is started (previous second shift). Here, the second shift start gear ratio GR3A is not a fixed value, but is set each time during such multiple shifts, and is a value set in consideration of the hydraulic response delay of the second shift. . That is, the first predetermined gear ratio GR3A is set so that the time point at which the second shift is actually started coincides with the end of the inertia phase (or the time from the end of the inertia phase to the actual start of the second shift is minimized). In other words, the gear ratio is set in advance in consideration of the response delay of the second shift, and is set as a gear ratio before a predetermined time (for example, 0.1 second) from the inertia phase end gear ratio GR3.

Accordingly, the second shift start gear ratio GR3A is set according to parameters such as the vehicle speed and the number of shift stages of the second shift stage. Specifically, the difference between the inertia phase end gear ratio (gear ratio at the second shift speed) GR3 and the second shift start gear ratio GR3A is set to increase as the vehicle speed decreases. Further, the difference is corrected so as to increase as the input torque to the transmission increases. This correction is executed by the start timing correction means 407 provided in the third shift control means 406. (Corresponding to claim 10 of the claims)
In the present embodiment, the parameter for starting the second shift is, as described above, “the second shift start gear ratio GR3A before reaching the gear ratio at which the first shift ends (inertia phase end gear ratio) GR3”. However, instead of this, a parameter corresponding to the first predetermined gear ratio may be used. In this case, for example, the turbine rotational speed, the output shaft speed of the transmission, the rotational speed of the wheels, and the like can be used as parameters.

  By the way, when the gear ratio reaches the second shift start gear ratio GR3A (t = t2 ′), as shown in FIG. 8C, the first shift is not yet completed, and therefore the first shift The shift and the second shift partially overlap. In particular, in the overlap period between the first shift and the second shift, two different control commands for the release control and the engagement control are output to the 2-6 brake 2-6 / B. That is, two different hydraulic pressure commands are output for one friction element (2-6 brake 2-6 / B).

In this apparatus, in order to avoid such a contradiction in control, the third shift control means 405 outputs the 2-6 brake 2-6 / B output from the first shift control means 403 after the start of the second shift. Is compared with the hydraulic pressure command value for the 2-6 brake 2-6 / B output by the second shift control means 404, and the larger one is always selected and the 2-6 brake 2-6 / This is output to the B hydraulic control valve 108 (select high control). (Corresponding to claims 1 and 11 of the claims)
By executing such select high control, the hydraulic pressure command value for the 2-6 brake 2-6 / B becomes a characteristic as indicated by a thick line in FIG. 8C, and two consecutive shifts are smoothly performed. And the occurrence of shift shock can be prevented or suppressed.

  Hereinafter, the downshift at the time of multiple shift will be specifically described along the flowchart of FIG. 7 in addition to FIG. 8. Basically, both the first shift (previous shift) and the second shift (next shift) It is the same control as a normal downshift (single downshift), and only a part thereof is different. Therefore, in the flowchart of FIG. 7, steps common to the flowchart described in FIG. 6 are given the same numbers, and redundant descriptions are omitted as much as possible.

First, the front shift will be described. The engagement side friction element (second friction element; low clutch LOW / C) is not changed at all with respect to the normal shift, and the same control as the normal shift is executed (step). S101-110).
Further, in the disengagement side friction element (first friction element; 2-6 brake 2-6 / B), only the normal shift steps S208 and S209 are changed. That is, when a second shift described later is started, it is desirable to quickly reduce the hydraulic pressure command value of the disengagement friction element in the first shift in order to prevent the stagnation of the shift.

Therefore, at the time of multiple shifts, correction is performed to reduce the hydraulic pressure of the 2-6 brake 2-6 / B to 0 at a timing earlier than the single 6 → 4 shift and at a steep slope (steps S208 ′ and S209 ′). ). This correction is executed by the end timing correction means 408 provided in the third shift control means 405. (Corresponding to the latter half of claim 3 in the scope of claims)
Specifically, as shown in FIG. 8, in this case, when the second predetermined gear ratio (GR3B) set before the second speed gear ratio GR3 for determining the end of the inertia phase is reached, the normal gear shift is performed. The hydraulic pressure is released to zero pressure at a gradient RR4S that is steeper than the gradient (first predetermined gradient; RR4). As a result, the 2-6 brake 2-6 / B is quickly released. Except for the above, the normal first shift (6 → 4 shift) is executed according to the control program stored in the A / T control unit 40, and the shift to the fourth speed is completed.

Note that the gradient (draft gradient) of the decrease in hydraulic pressure at this time is corrected so as to become steeper as the input torque to the 2-6 brake 2-6 / B increases. (Corresponding to claim 8 of the claims)
This is because as the input torque increases, the hydraulic pressure of the 2-6 brake 2-6 / B increases and it takes time until the release, and if the hydraulic pressure is not released quickly, there is a risk that the shift will be stagnant during the shift. It is. Therefore, as described above, by correcting the draft according to the input torque, it is possible to suppress stagnation, interlock, blow-up, and the like during the shift.

Next, the second shift (next shift) will be described. In this second shift, the steps for executing the same processing as the first shift (previous shift) are assigned the same numbers as in the first shift, and duplicate descriptions are omitted as much as possible.
When normal shift control (control similar to the first shift) is applied to the second shift as it is, the 2-6 brake 2-6 / B (first friction element) is engaged by the second shift control means 404. However, since the first gear shift has not yet been completed, the first gear shift control means 403 should release the 2-6 brake 2-6 / B. Hydraulic pressure command value is output. That is, in the overlap period after the second shift start (t2), two different control commands for the release control and the engagement control are output for one friction element (2-6 brake 2-6 / B). Will be.

  Therefore, in this case, as described above, the hydraulic pressure command value for the 2-6 brake 2-6 / B output from the first shift control means 403 and the 2-6 output from the second shift control means 404 are output. The hydraulic pressure command value for the brake 2-6 / B is compared with the third shift control means 405, and the higher one is selected and output as the hydraulic pressure command value for the 2-6 brake 2-6 / B. (Step S100). This select high control is executed until the second shift is completed.

Further, in such a multiple shift second shift, as shown in FIG. 8C, the precharge control of the disengagement side friction element is prohibited. (Corresponding to claim 5 of the claims) That is, in the flowchart, the prohibition of the precharge control (step S101 ′) is applied instead of the precharge control (step S101) of the first shift.
This is a state in which the piston stroke of the 2-6 brake 2-6 / B is finished by the first shift control means 403 at the start of the second shift, and in this state, a high hydraulic pressure for backlash is output. Then, the actual hydraulic pressure also follows the hydraulic pressure command value, and there is a possibility that a shock will occur due to the generation of clutch capacity.

Therefore, the occurrence of shock is prevented by canceling the precharge control of the engagement side friction element at the start of the second shift. In this case, as the initial value of the engagement-side friction element for the second shift, a predetermined value PA2 + learning amount set at the end of the precharge control of the engagement-side friction element for the first shift is applied.
Thereafter, the predetermined value PA2 + learning amount is held until the predetermined time T1 elapses in the same manner as in the first shift (step S102), and then the piston stroke control similar to that in the first shift is performed (step S103).

In the piston stroke control, the piston of the engagement side friction element gradually strokes under a constant hydraulic pressure value. Here, in the first shift described above, during the piston stroke control, when the hydraulic switch is turned on, the end of the piston stroke control is determined, and the process proceeds to the next AC21.
However, in this second shift, the engagement-side friction element is the same friction element (2-6 brake 2-6 / B) as the release-side friction element of the first shift, and at the start of the second shift that overlaps the first shift. Since the hydraulic pressure has already been sufficiently increased, the hydraulic switch is already on at the start of the second shift. Therefore, if the end of the piston stroke is determined by using the hydraulic switch on as a trigger, as in the first shift, the piston stroke phase will be lost.

For this reason, in the second shift, it is prohibited to use the hydraulic switch on as a trigger (corresponding to claim 6 of the claims), and the control shifts to the switching control on condition that a predetermined time T2 + T10 has passed ( Step S104 '). Thereafter, the same process as the first shift is executed for the engagement side friction element (see steps S105 to S110).
As described above, the hydraulic pressure command value is set in accordance with steps S100 to S110 in the engagement side friction element of the second speed change, and the larger one is compared with the hydraulic pressure command value of the release side friction element of the first speed change. Is selected as the hydraulic command value to be actually output (select high).

As a result, the hydraulic pressure command value for the friction element (2-6 brake 2-6 / B) that is released in the first shift and engaged in the second shift has a characteristic as indicated by a thick solid line in FIG. It is possible to achieve control consistency when shifting is overlapped. As a result, two consecutive shifts can be performed smoothly, and the occurrence of shift shocks can be prevented or suppressed.
On the other hand, the following control is executed in the disengagement side friction element (third friction element; high clutch H / C). Here, at the time of a single shift from 4 to 2, the second shift control means 404 sets the hydraulic pressure of the high clutch H / C to start shifting for the purpose of preventing hydraulic undershoot as in the first shift described above. At the same time, the second hydraulic pressure command value (second hydraulic pressure value TR2; the upper hydraulic pressure value at which the high clutch H / B cannot transmit the input torque alone) has a margin. The hydraulic pressure value is decreased in a step-like manner to TR2 + TR1) (see the dotted line in FIG. 8C).

  However, when the sequential shift is executed as in the present embodiment and the sharing ratio at the first shift stage is larger than the sharing ratio at the second shift stage, the high frictional force that is the third friction element at the time of overlap is obtained. Since the clutch H / C may slip, an initial pressure correction corresponding to the sharing ratio is performed for the purpose of preventing the high clutch H / C from slipping (step S201 ′). Here, the sharing ratio refers to the ratio of the torque that each friction element has at each gear position when the input torque is 1.

  This will be described in detail. When the sharing ratio (0.722) of the second gear (fourth speed) is smaller than the sharing ratio (1.000) of the first gear (6th speed) of the high clutch H / C, the first gear shift is performed. When the shift control is executed based on the normal second shift data, the hydraulic pressure of the third friction element is lowered to the equivalent of the fourth speed sharing ratio before the fourth speed is determined, that is, the sixth gear sharing ratio is required. I will let you. That is, the capacity of the high clutch H / C is equal to the first gear ratio (6th gear) sharing ratio (1.000) / second gear speed (fourth gear) sharing ratio (0.722) = 1.39 minutes. There is a possibility that the gear ratio will increase due to insufficient capacity.

  Therefore, in this apparatus, the second hydraulic pressure value is appropriately corrected according to the sharing ratio between the first gear and the second gear, thereby suppressing the gear ratio from rising. (Corresponding to claim 7 of the claims) If the relationship of the sharing ratio of the third friction element is reversed (first gear sharing ratio <second gear sharing), the capacity is insufficient. Therefore, it is not necessary to perform such correction.

  Then, the hydraulic pressure command value is reduced to the third hydraulic pressure command value over a predetermined time T1S set for the next shift (step S202 ′), and thereafter, the pre-change control similar to the normal shift (step S203). Migrate to The predetermined time T1S in step S202 ′ is set to a time shorter than the predetermined time T14 in the normal downshift. This is to reduce the stagnation time of the gear in the intermediate stage.

  In the pre-replacement control, the hydraulic pressure TR2 corresponding to the input torque is maintained until the piston stroke of the engagement-side friction element is completed, and the gear position is maintained on the release side. In the normal shift, when the on-off of the hydraulic switch is detected, the next switching control is performed. However, in the second shift of the multi-shift, it is prohibited to use the hydraulic switch on as a trigger, and a predetermined time T2 + T10 has elapsed. If it determines, it will transfer to the next change control (step S204 ').

The prohibition of using the hydraulic switch on as a trigger here is to prevent the hydraulic switch from being in an on state from being out of synchronization with the fastening side switching control start timing as described above. By making the count times of both the engagement side and the release side coincide with each other, the friction elements on the engagement side and the release side simultaneously shift to the switching control.
Thereafter, the same control as the normal shift is executed. In other words, the hydraulic pressure is gradually reduced (inertia phase control) at a predetermined gradient according to the input torque and the vehicle speed, and when the predetermined gear ratio is reached, the hydraulic pressure is released toward the hydraulic pressure 0 and the shift is finished.

As described above, even during multiple shifts, the optimum shift control is basically executed using the control programs (control data) stored in advance in the first and second shift control means 403 and 404. There is no need to create a new program for the multiple shift control, and an increase in shift data can be suppressed to a minimum.
Since the second shift is started before the end of the first shift, the time to reach the final target shift stage without reducing the hydraulic pressure of the first friction element (2-6 brake 2-6 / B) to zero. Can be shortened. In other words, the hydraulic pressure of the first friction element is continuously connected to the hydraulic pressure of the first friction element by setting the hydraulic pressure of the first friction element to the select high that selects the higher hydraulic pressure command value after the timing at which the shifts overlap. (Refer to the thick solid line in FIG. 8 (c)) Two consecutive shifts can be performed quickly and smoothly, and the occurrence of shift shocks can also be suppressed.
3.2.3 Upshift at Normal Time Next, the upshift at the time of normal shift (n stage → n + 1 stage) will be described with reference to FIGS. 9 and 10. FIG. 9 is a time for explaining the normal upshift. FIG. 10 is a flowchart of the chart.

  When upshifting is started, pre-charge control (backpacking control) is executed simultaneously with the start of shifting in the engagement side friction element (AC11, steps S301 and S302), and then piston stroke control is executed (AC12, Steps S303 and S304). The precharge control and the piston stroke control have the same control contents as the downshift described above, and thus detailed description thereof is omitted.

Next, AC21 switching control is started. In this switching control, the hydraulic pressure command value is increased at a predetermined gradient RA2 set in advance based on the input torque and the vehicle speed (step S305). When the predetermined gear ratio GR5 is reached, the switching control is terminated and the next inertia is performed. The process proceeds to phase control (step S306).
Here, the predetermined gradient RA2 is set so that the pull gradient (the decrease gradient of the output shaft torque during the torque phase) is optimal, and the predetermined gradient RA2 is set to a larger value as the input torque increases. This hydraulic gradient is also intended to prevent hydraulic surges and shift shocks when switching from switching control to inertia phase control. Note that, during the power-off upshift, the inertia phase is detected before the start of the switching control, and the inertia phase may be shifted to without executing this control.

When the inertia phase control is entered, the hydraulic pressure is increased at a predetermined gradient RA3 set based on the input torque and the vehicle speed (step S307). Here, the gradient RA3 is smaller than the gradient RA2 of the switching control, and the oil pressure is increased relatively slowly with a gentle gradient.
Then, when the gear ratio GR reaches the inertia phase end gear GR2 described above, this control is ended (step S308).

  Next, the process proceeds to inertia phase end control (AC41). Here, the hydraulic pressure is increased over a predetermined time T8 at a gradient RA4 (constant value) larger than the predetermined gradient RA3. If the hydraulic pressure command value is raised at a stretch, there is a possibility that a shift shock will occur due to variations in the detection of the end of the inertia phase. For this reason, the hydraulic pressure is increased at a predetermined gradient RA4 (steps S309 and S310).

Then, when the predetermined time T8 has elapsed, the hydraulic pressure command value (duty) is set to 100%, the maximum hydraulic pressure (MAX pressure) is output, and the shifting of the engagement side friction element is completed.
On the other hand, in the disengagement side friction element, undershoot prevention control is first executed (steps S401 and S402), and thereafter, control before switching is performed (steps S403 and S404), as in the downshift. That is, as shown in FIG. 9, when the upshift is started, the hydraulic pressure command value is reduced to a predetermined command value TR2 in the disengagement side friction element. At this time, in order to prevent an excessive decrease (undershoot) in the hydraulic pressure, a slightly higher hydraulic pressure command value (+ TR1) is output with respect to the target hydraulic pressure command value TR2 at the start of shifting, and then the hydraulic pressure command value Is gradually reduced to the target hydraulic pressure command value TR2 over a predetermined time T15. The hydraulic pressure command value TR2 is a limit value at which the clutch of the disengagement side friction element does not slip.

By keeping the hydraulic pressure at such a limit value TR2, when the time shifts to the change control after the time T15, the clutch capacity is immediately reduced and the gear shift proceeds as the hydraulic pressure decreases. Note that, at the time of power-off shift up, a constant hydraulic command value TR3 (<TR2) is applied instead of the hydraulic command value TR2.
Next, change control (RC21) is started. In this switching control, the gradient of the hydraulic pressure command value (third predetermined gradient) is set so that the hydraulic pressure command value TR3 at the time of the power-off shift up is set after the predetermined time T16 has elapsed, and the hydraulic pressure command is gradually increased with this gradient. The value is reduced (step S405).

  Then, when the predetermined time T16 elapses and the hydraulic pressure command value TR3 is reached, the hydraulic pressure command value TR3 is held until the gear ratio becomes the inertia phase determination gear ratio GR1, and then the control shifts to the RC 31 inertia phase removal control. If the gear ratio reaches the inertia phase determination gear ratio GR1 before the predetermined time T16 elapses, the control shifts to inertia phase omission control at this time (step S406).

  When the control shifts to the inertia phase removal control, the hydraulic pressure command value is gradually reduced with a gentle gradient so that the hydraulic pressure becomes zero at the predetermined time T17 (step S407). Here, the reason why the hydraulic pressure command value is not set to 0 at a stretch is to avoid occurrence of shock. That is, the predetermined time T17 is set as the time required for the gear ratio to reach the gearshift end gear ratio from the inertia phase determination gear ratio GR1, and the hydraulic pressure is gradually reduced during the predetermined time T17, so that the shock is reduced. The shift is terminated without occurring.

Then, the hydraulic pressure is reduced in this way, and when a predetermined time T8 has elapsed since the inertia phase end gear ratio GR2 is determined, the hydraulic pressure command value is set to 0 and the shift is completed (step S408).
As described above, the first shift control means 403 performs the upshift of the normal shift.
3.2.4 Upshift at Multiple Shift Next, the control at the time of multiple shift upshift will be described with reference to FIG. 12. FIG. 12 shows the characteristics of the upshift at the multiple shift of 3 → 4 → 5. FIG. 8 is a time chart showing, like FIG. 8, (a) is the throttle opening TH, (b) is the gear ratio GR of the transmission, and (c) is the hydraulic command value for the friction element that is engaged or released at the time of shifting. Each characteristic is shown.

In such an upshift of 3 → 4 → 5, the 3-5 reverse clutch 3-5R / C is controlled to be released → engaged, so that the 3-5 reverse clutch 3-5R / C It corresponds to one friction element. The high clutch H / C corresponds to the second friction element, and the low clutch LOW / C corresponds to the third friction element.
Now, the traveling condition fluctuates during traveling at the third speed (first gear), and the target gear is set to the fourth speed (second gear) by the shift map (target gear determining means) 401. Then, an upshift from the third speed to the fourth speed (first shift or forward shift) is started based on a control signal from the first shift control means 403 (t1 in FIG. 12).

Since the first shift (previous shift) is the same shift control as the above-described normal upshift, the description regarding the first shift is omitted.
Now, as the first gear shift proceeds, the gear ratio GR starts to change from the previous second gear ratio to the third gear ratio (start of inertia phase; see t1 ′ in FIG. 12). After the determination of the start of the inertia phase, when the target shift speed changes from the fourth speed (second shift speed) to the fifth speed (third shift speed), the target shift speed to this fifth speed is determined (when the shift is determined). The first predetermined gear ratio (second shift start gear ratio or forward gear) before the gear ratio and the gear ratio (inertia phase end gear ratio) GR2 for determining the end of the 3 → 4 shift (first shift) Ratio) GR2A, and if the shift to the third shift stage is determined after the gear ratio reaches the second shift start gear ratio GR2A, the second shift control means 405 causes the second shift. Is started, and the second shift by the second shift control means 404 is immediately executed.

  Further, if the gear ratio at the time of changing the target shift stage is before the second shift start gear ratio GR2A, the second shift control means 405 does not immediately start the second shift but the second shift control means 405 performs the second shift control. Prohibit starting. After that, when the gear ratio reaches the second shift start gear ratio GR2A, the prohibition of the second shift is canceled in the same manner as the above-described downshift, and the third shift control means 405 causes the 4 → 5 shift (second shift). The start of (shift) is instructed (see t2 in FIG. 12).

  Here, when the second shift start gear ratio GR2A before the end of the inertia phase is reached, the second shift is started without waiting for the end of the first shift for the same reason as during the downshift. That is, if the second shift is started after waiting for the end of the first shift, the delay in the hydraulic response at the start of the second shift causes a delay between the end of the first shift and the start of the second shift. This is because the stagnation time occurs, and as a result, the shift time may increase.

Therefore, in the present device, when the target shift speed is changed to the third shift speed after the start of the inertia phase, when the gear ratio becomes the second shift start gear ratio GR2A before the inertia phase end gear ratio GR2, the second shift speed is changed. Is started (previous second shift).
Similarly to the downshift, the second shift start gear ratio GR2A is not a fixed value, but is set each time during such multiple shifts, and is set in consideration of the hydraulic response delay of the second shift. Is done. In other words, the first predetermined gear ratio is set so that the time point at which the second shift is actually started coincides with the end of the inertia phase (or the time from the end of the inertia phase to the start of the second shift is minimized). ), Which is a gear ratio set in advance in consideration of the response delay of the second shift, and the second shift start gear ratio GR2A so that the time from the start of the second shift (t2) to the end of the inertia phase is a fixed time. Is set.

The method for setting the second gear shift start gear ratio GR2A is the same as the method for setting the second gear shift start gear ratio GR3A at the time of downshift, and therefore the description of the method for setting and correcting the gear ratio GR2A is omitted. .
When the second shift is started at t = t2, a hydraulic pressure command value for engaging the 3-5 reverse clutch 3-5R / C (first friction element) is output in terms of shift control. At this time, since the first shift has not been completed, the hydraulic pressure command value is output to release the 3-5 reverse clutch 3-5R / C in the first shift. That is, as shown in FIG. 12, in the overlap period from the second shift start (t2) to the first shift end (t3), one friction element (3-5 reverse clutch 3-5R / C) Two different control commands, that is, release control and fastening control are output.

  That is, in such a front shift and next shift overlap period, two control commands different in release control and engagement control are output to the 3-5 reverse clutch 3-5R / C. In this device, in order to avoid such a control contradiction, the third shift control means 405 outputs the 3-5 reverse clutch 3-5R output from the first shift control means 403 after the start of the second shift. The hydraulic pressure command value for / C and the hydraulic pressure command value for 3-5 reverse clutch 3-5R / C output by the second shift control means 404 are compared, and the larger one is finally selected and finally 3-5 It outputs to the hydraulic control valve 109 of the reverse clutch 3-5R / C (select high control).

Then, by executing such select high control, the hydraulic pressure command value for the 3-5 reverse clutch 3-5R / C becomes a characteristic indicated by a thick solid line in FIG. The shift shock can be prevented or suppressed during upshifting as well as downshifting.
Further, in the normal speed change, when shifting to the inertia phase after the switching control, the hydraulic pressure of the first friction element is reduced to zero pressure with a predetermined gradient (third predetermined gradient) to release the first friction element (FIG. 9). RC31), at the time of this multiple shift, the end timing correction means 408 prohibits the first friction element from being reduced to zero pressure and is held at a predetermined hydraulic pressure (release pressure) until the start of the second shift. The hydraulic pressure command value is corrected. Here, the release pressure is a hydraulic pressure command value that allows the clutch of the first friction element to maintain a state corresponding to the completion of the piston stroke (corresponding to claim 4 of the claims).

  Such correction is performed after the completion of the piston stroke of the second friction element (after the completion of the switching control AC21) after the determination of the piston stroke of the second friction element as in the normal first shift at the time of multiple shifts. If the control is performed so as to release to zero pressure at a predetermined gradient, the hydraulic pressure is released before the start of the second shift, and the piston stroke of the first friction element must be made again at the start of the second shift. This is because the actual start of shifting is delayed.

Therefore, at the time of multiple shifts (upshifts), as described above, the release timing remains at the end of the first shift by the end timing correction means 408, thereby preventing a stagnation of the gear ratio at the second shift stage. Thus, the shift from the first shift to the second shift can be performed smoothly and quickly without giving the driver a sense of incongruity.
Hereinafter, the upshift operation at the time of multiple shift will be described along the flowchart of FIG. 11 in addition to FIG. As described above, the first shift (previous shift) is not changed except for maintaining the release pressure at the end of the first shift with respect to the normal upshift (single upshift). Is omitted.

For the second shift (next shift), the control content different from the upshift of the normal shift will be mainly described, and the same steps as those of the normal shift described in FIG. The explanation is omitted as much as possible.
The second shift control means 404 starts the second shift when the first predetermined gear ratio (second shift start gear ratio or forward gear ratio) GR2A is detected. When the second shift is started, first, the disengagement hydraulic command value of the first friction element (3-5 reverse clutch 3-5R / C) for the first shift and the engagement of the first friction element for the second shift are performed. The side high oil pressure command value is compared, and the select high that always selects and outputs the larger one is executed (step S300). This select high control is executed by the third shift control means 405.

  Next, precharge control of the disengagement side friction element is prohibited (step S301 ′; corresponding to claim 5 of the claims). This is step S101 of “downshift at the time of multiple shifts” in 3.2.2. For the same reason as described in ′. That is, at the start of the second shift, the release pressure of the 3-5 reverse clutch 3-5R / C remains by the first shift control means 403, and if a high hydraulic pressure for backlash is output in such a state. This is because the actual oil pressure follows the oil pressure command value and the clutch capacity is generated, which may cause a shock. In this case, as the initial value of the engagement-side friction element for the second shift, a predetermined value PA2 + learning amount set at the end of the precharge control of the engagement-side friction element for the first shift is applied.

Thereafter, the predetermined value PA2 + learning amount is held until the predetermined time T1 elapses in the same manner as in the first shift (step S302), and then the piston stroke control similar to that in the first shift is performed (step S303).
In the piston stroke control, the hydraulic switch is already turned on at the start of the second shift, and if the end of the piston stroke is determined by using the hydraulic switch on as a trigger as in the first shift, the piston stroke phase is lost. For this reason, in the second shift, it is prohibited to use the hydraulic switch on as a trigger (corresponding to claim 6), and the control shifts to the condition that the predetermined time T2 has passed (step S304 ′). Thereafter, the same process as the first shift is executed for the engagement side friction element (see steps S105 to S110).

Next, the control of the disengagement side friction element will be described. The second shift control means 404 prohibits undershoot prevention control (see step 401 in FIG. 10) executed in the previous shift, The sharing ratio correction is performed in the same manner as in step S201 ′ of “downshift at the time of multiple shifts” (step S401 ′) to suppress the gear ratio from rising.
Specifically, when the sharing ratio of the second gear (fourth speed) is smaller than the sharing ratio of the first gear (third speed) of the third friction element (low clutch LOW / C), the correction ratio is “ The first gear ratio / the second gear ratio "is obtained, and the hydraulic pressure command value is corrected by multiplying the hydraulic pressure TR1 by this correction ratio.

Next, the hydraulic pressure command value is reduced to the third hydraulic pressure command value TR2 by taking this hydraulic pressure command value for a predetermined time T1S set exclusively for the next shift (step S402 ′). The predetermined time T1S in step S402 ′ is set to a time shorter than the predetermined time T15 in the normal upshift. This is to reduce the stagnation time of the gear in the intermediate stage.
Thereafter, the routine proceeds to the pre-change control (step S403) similar to the normal shift. In the pre-replacement control, the hydraulic pressure TR2 corresponding to the input torque is maintained until the piston stroke of the engagement-side friction element is completed, and the gear position is maintained on the release side. In the normal shift, when the on-off of the hydraulic switch is detected, the process shifts to the next switching control. However, in the second shift of the multi-shift, it is prohibited to use the hydraulic switch on as a trigger (corresponding to claim 6). When it is determined that the predetermined time T2 has elapsed, the next shift control is performed (step S404 ').

The prohibition of the hydraulic switch on as a trigger here is to prevent the hydraulic switch from being originally on and from being out of synchronization with the switching control start timing on the fastening side, as described above. By making the count times of both the engagement side and the release side coincide with each other, the friction elements on the engagement side and the release side simultaneously shift to the switching control.
Thereafter, the same control as the normal shift is executed. In other words, the hydraulic pressure is gradually reduced (inertia phase control) at a predetermined gradient according to the input torque and the vehicle speed, and when the predetermined gear ratio is reached, the hydraulic pressure is released toward the hydraulic pressure 0 and the shift is finished.

Then, by executing such select high control, the hydraulic pressure command value for the 3-5 reverse clutch 3-5R / C becomes a characteristic indicated by a thick solid line in FIG. The shift shock can be prevented or suppressed during upshifting as well as downshifting.
Since the automatic transmission control apparatus according to one embodiment of the present invention is configured as described above, its operation will be described below with reference to the flowcharts shown in FIGS. 13 and 14. 13 and 14 show the operation when the target shift speed is changed to the third shift speed (second speed) during the shift from the first shift speed (sixth speed) to the second shift speed (fourth speed). In the flowchart shown, the shift determination from the first shift speed (sixth speed) to the second shift speed (fourth speed) is made (that is, when the target shift speed is changed from the sixth speed to the fourth speed). To do.

  When the shift determination from the 6th speed to the 4th speed is made, it is first determined whether or not re-shifting is prohibited (step SA1). Here, the re-shift refers to a shift control in which the target shift speed is newly set to other than the fourth speed and the new target shift speed is set. Whether or not re-shifting is prohibited is specifically determined whether or not the inertia phase is started in the first shift, and if it is after the start of the inertia phase, it is determined that re-shifting is prohibited and before the start of the inertia phase. In this case, it is determined that re-shifting is possible.

If re-shifting is possible, it is next determined whether or not the target shift speed has been changed to other than the fourth speed (current target shift speed) (step SA2). And a shift (re-shift) with respect to the new target shift speed is executed (step SA3). If the target shift speed is not changed, the process returns to step SA1.
Further, when it is determined in step SA1 that re-shifting is prohibited, it is determined whether or not the target shift stage has been changed. Specifically, it is determined whether or not the new target gear stage has changed to a speed other than the fourth speed (step SA17). If the speed is other than the fourth speed, the new target gear speed is the sixth speed or higher that is the current gear speed. In other words, it is determined whether or not the gear is on the high speed side (step SA4). If the target shift speed is 4th speed, it is determined whether or not the current 6-4 shift has ended (step SA18). When the 6-4 shift ends, the control is terminated as 4th speed steady (step S19). To do.

  On the other hand, when the process proceeds to step SA4, if the target shift speed is larger than the current shift speed, it is a case where the downshift is changed to the upshift, and therefore return shift control is performed (step SA5). Here, the return shift control is a control for canceling the downshift and shifting to the upshift. However, the return shift control is well known and has a low relevance to the present invention, and a detailed description thereof will be omitted.

  If it is determined No in step SA4, it is next determined whether the target shift speed is less than the fourth speed (step SA6). If it is also determined No in step SA6, the final target shift speed is not less than 4th speed and less than 6th speed. Therefore, after the end of the shift to 4th speed is determined (step SA7), the target shift speed is 4 It is determined whether the speed is 5th or 5th (step SA8). If the target shift speed is 4th, a steady operation at 4th speed is performed as it is (step SA9). The shift control from the fourth speed to the third speed is executed (step SA10).

  On the other hand, when it is determined Yes in step SA6, the second or third speed (third speed) is set as the new target speed after the shift from the sixth speed to the fourth speed is determined. In this case, shifting to the second speed or the third speed is prohibited until the prohibition of re-shifting is canceled. Specifically, it is determined whether the actual gear ratio is less than the second shift start gear ratio (previous gear ratio) GR3A, that is, whether the actual gear ratio is before the second shift start gear ratio GR3A is reached. However, if the actual gear ratio is before reaching the second shift start gear ratio GR3A, the shift prohibition is maintained until the second shift start gear ratio GR3A is reached.

  Further, when the actual gear ratio reaches the second shift start gear ratio GR3A, the shift prohibition is released, and the third shift stage is a friction that is engaged → released in the first shift and released → engaged in the second shift. It is determined whether or not the gear stage has an element (step SA12). In step SA12, a shift combination (shift pattern) having a friction element of engagement → release → engagement is stored in advance based on the operation diagram of the friction element in FIG. It is executed by determining whether or not it corresponds to the stored shift pattern.

  If such a friction element does not exist, that is, if the third speed is the third speed, the normal engagement / release control of the friction element is executed through the route No (step) SA13). Further, when there is a friction element that is disengagement → engagement in the first shift and engagement → disengagement in the second shift as described above, that is, when the third shift speed is the second speed, the third shift control means 405 is provided. Is executed (step SA14). The subroutine in step SA14 will be described later.

When the end of the shift control from the 6th speed to the 4th speed (first shift) is determined (step SA15), the normal shift control from the 4th speed to the 2nd speed (second shift) is executed (step SA16). . Thus, until the first shift is completed, the third shift control means 405 ensures the consistency of the hydraulic command for each friction element, and the control is optimized.
Next, the subroutine of step SA14 will be described with reference to FIG. 14. This subroutine is started when it is determined that the second shift start of the multiple shift is performed. The removal preparation torque sharing ratio correction (here, high clutch H / C) is corrected (step SB1), and the removal preparation time T1S is set (step SB2). And in this extraction preparation time T1S, the hydraulic pressure command value is gradually lowered to the above-described third hydraulic pressure command value.

Further, at the time of such multiple shifts, it is prohibited to use the hydraulic switch on of the engagement side friction element of the second shift as a trigger (step SB3).
On the other hand, when the second shift is started, the hydraulic pressure command value for the 2-6 brake 2-6 / B in the first shift and the hydraulic pressure for the 2-6 brake 2-6 / B in the second shift. Compared to the command value, the larger one is selected, and the selected high pressure command value is output as the hydraulic command value for the final 2-6 brake 2-6 / B (step SB4).

  Next, the current actual gear ratio is compared with the second shift start gear ratio GR3A (step SB5). If it is determined that the actual gear ratio has reached the second shift start gear ratio GR3A, the first shift (previous shift) is performed. The advance control is performed to advance the hydraulic pressure release timing (extraction timing) of the release side friction element earlier than the original timing (step SB6), and the draft is changed (corrected) to a steep slope (step SB7). Steps SB5 to SB7 are executed only during the downshift, and the process proceeds from step SB4 to step SB8 during the upshift.

  After correcting the draft, it is determined whether or not the first shift has been completed (step SB8), and if the end of the first shift is determined, the 4 → 2 shift in the multiple shift is completed (step SB9). That is, the above-described select high control ends in step SB9. Thereafter, a normal 2-1 shift programmed in advance in the control unit 40 is executed (step SB10).

As described above in detail, according to the automatic transmission control device according to the embodiment of the present invention, the first shift control unit 403 and the second shift control unit 404 are basically configured even during multiple shifts. By performing shift control using this data, an increase in shift data can be suppressed to a minimum.
In addition, since the second shift is started before the end of the first shift in the first shift and the second shift, the time to reach the final target shift stage can be obtained without significantly reducing the hydraulic pressure of the first friction element. Can be shortened. That is, the hydraulic pressure of the first friction element is set to the select high after the timing at which the shifts overlap, so that the hydraulic pressure of the first friction element is continuously connected, and two successive shifts can be performed quickly and quickly. This can be performed smoothly, and the occurrence of shift shock can also be suppressed.

In addition, since the second shift control is started based on the target shift stage at the time when the first predetermined gear ratio (second shift start gear ratio or advance gear ratio) becomes GR3A, even if the target shift stage changes again. Thus, it is possible to smoothly shift to the final target shift stage without complicating the control. (Effects corresponding to claims 1 and 11 above)
In addition, when the change of the target shift stage is determined in the first shift and the second shift, the second shift is performed before the end of the first shift, so that the time during which the gear ratio stagnates in the second shift stage can be shortened. Thus, the time required to reach the third shift speed, which is the final target shift speed, can be shortened. (Effects corresponding to claim 2 above)
Also, during downshifting, the timing of lowering toward zero pressure (extraction timing) among the hydraulic characteristics of the second friction element in the first shift is a relatively late timing so as to smooth the torque fluctuation at the end of the shift. Since the hydraulic pressure is lowered with a relatively slow gradient, even if the second shift start command is issued during the first shift, the hydraulic pressure of the second friction element becomes excessive, and the Although there is a possibility of stagnation at the lock or the second gear position (fourth speed), in this embodiment, the hydraulic pressure is lowered earlier and the hydraulic pressure is lowered steeply compared to the case where the first first gear shift is performed. By doing so, interlock and a stagnation of the gear ratio can be prevented. (Effects corresponding to claim 3 above)
Further, at the time of upshifting, it is prohibited to release the hydraulic pressure of the first friction element to zero pressure before the end of shifting, and the hydraulic pressure of the first friction element is maintained at a hydraulic pressure (release pressure) equivalent to the completion of the piston stroke. By correcting the command value, the stagnation of the gear ratio at the second gear can be prevented. That is, when it is determined that the piston stroke of the second friction element is completed as in the normal first shift, if the hydraulic pressure of the first friction element is reduced to zero pressure, the hydraulic pressure can be released before the start of the second shift. Therefore, the piston stroke of the first friction element must be made again at the start of the second shift, the actual start of the second shift is delayed, the gear ratio is stagnated at the second shift stage, and the driver feels uncomfortable. There is a possibility that the stagnation of the gear ratio can be prevented by maintaining the hydraulic pressure of the first friction element at the release pressure. (Effects corresponding to claim 4 above)
In addition, since the precharge control at the start of the second shift is prohibited at the time of the multiple shift as described above, the discontinuity of the actual hydraulic pressure of the first friction element that continuously releases and engages is eliminated, and the shift shock is Can be prevented. That is, although the hydraulic pressure of the first friction element released in the first shift is low, the piston is in a stroke state. At this time, if precharging is performed in the same manner as in the normal state during the second shift, the first friction element is The command hydraulic pressure of the second shift for the element becomes too high, and a shift shock due to the sudden engagement of the first friction element occurs.

On the other hand, by prohibiting the precharge, the sudden engagement of the first friction element can be suppressed, so that a shift shock can be prevented. (Effects corresponding to claim 5 above)
In addition, during multiple shifts, information from the hydraulic switch (piston stroke determining means) is canceled during the second shift, that is, prohibiting the on-off of the hydraulic switch as a trigger can prevent shift shock. That is, when the start timing of the hydraulic switching control of the first friction element is determined based on the result of the hydraulic switch as in the normal second shift, the first friction element released in the first shift is Since the piston stroke is completed at the start of the second shift, a shift command to the switching control is output simultaneously with the start of the second shift, and a shift shock may occur.

Therefore, in the second shift, the information of the hydraulic switch is ignored, and the shift shock is prevented by starting the switching control after a predetermined time (T1 for the engagement-side friction element and T1S for the release-side friction element) has elapsed. it can. (Effects corresponding to claim 6 above)
Further, when the sharing ratio at the second shift stage is larger than the sharing ratio at the first shift stage in the third friction element, the second hydraulic pressure value of the third friction element is set to the sharing ratio in the first shift stage. Since the correction is performed based on the ratio with the sharing ratio in the second shift speed, it is possible to prevent the gear ratio from rising due to insufficient clutch capacity. (Effects corresponding to claim 7)
Further, since the hydraulic pressure of the second friction element increases as the input torque increases, it takes time until release, and there is a possibility of excessive stagnation at the interlock or intermediate stage. However, the second friction element depends on the input torque. By correcting the oil pressure drop gradient (first predetermined gradient or draft), it is possible to suppress stagnation, interlock, blow-up, and the like at the intermediate speed. (Effects corresponding to claim 8)
Further, as the vehicle speed increases and the input torque increases, the parameter corresponding to the second predetermined gear ratio or the second predetermined gear ratio is set to the high speed side when downshifting, and to the constant speed stage when upshifting. By correcting to the side, this control can be performed appropriately according to the vehicle speed and input torque, and stagnation and interlock at the intermediate gear stage can be reliably prevented regardless of the driving conditions of the vehicle. . (Claim 9)
By the way, when the data of the second shift control means 404 is used as much as possible, the timing at which the second shift control is started during execution of the first shift control is considered in consideration of the response delay of the actual hydraulic pressure with respect to the command hydraulic pressure. It is necessary to set only as early as possible. In addition, the response of the actual hydraulic pressure is constant as long as the viscosity of the hydraulic oil does not change. Therefore, a constant (or fixed) gear ratio before reaching the gear ratio GR3 at the end of the inertia phase is used, and when the constant gear ratio is reached, the second shift is started to offset the response delay of the actual hydraulic pressure. do it. However, since the change rate of the gear ratio varies depending on the torque and the vehicle speed, the time to reach the gear ratio GR3 at the end of the inertia phase changes depending on the torque and the vehicle speed. As a result, when the second shift control is started at the timing when the fixed gear ratio is reached, depending on the torque and the vehicle speed, stagnation, interlock, and blow-up may occur at the intermediate shift stage. Correction is made so that the difference between the gear ratio GR3A for starting the second shift and the gear ratio GR3 for completing the inertia phase increases as the vehicle speed decreases, and the difference increases as the input torque of the transmission 1 increases. By doing so, it is possible to correct the start timing of the second shift to an appropriate timing, and it is possible to prevent stagnation at the intermediate shift stage, interlock, blow-up, and the like. (Effects corresponding to claim 10 above)
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the configuration of the automatic transmission may be a six-speed automatic shift skeleton disclosed in Japanese Patent Application Laid-Open No. 2003-106439, or may be applied to an automatic transmission having seven or more speeds. good.

1 is a skeleton diagram schematically showing a configuration of an automatic transmission of 6 forward speeds and 1 reverse speed to which the present invention is applied. FIG. It is a figure which shows the operating state of each friction element in each gear stage of the control apparatus of the automatic transmission concerning one Embodiment of this invention. 1 is a schematic diagram illustrating a hydraulic circuit and an electronic shift control system of a control device for an automatic transmission according to an embodiment of the present invention. It is a typical block diagram which shows the function structure of the principal part of the control apparatus of the automatic transmission concerning one Embodiment of this invention. It is a time chart which shows the characteristic at the time of the normal downshift of the control apparatus of the automatic transmission concerning one Embodiment of this invention. 4 is a flowchart for explaining an operation during a normal downshift of the control device for the automatic transmission according to the embodiment of the present invention. It is a flowchart for demonstrating the effect | action of the control apparatus of the automatic transmission concerning one Embodiment of this invention, Comprising: It is a figure explaining the change point with respect to the downshift of normal transmission. FIG. 4 is a time chart showing characteristics during downshift of 6th speed → 4th speed → 2nd speed of the control device for an automatic transmission according to the embodiment of the present invention, where (a) shows a throttle opening TH, and (b) shows a throttle opening TH. The gear ratio GR, (c) of the transmission indicates the characteristic of the hydraulic pressure command value with respect to the friction element that is engaged or released at the time of shifting. It is a time chart which shows the characteristic at the time of the normal upshift of the control apparatus of the automatic transmission concerning one Embodiment of this invention. 3 is a flowchart for explaining an operation during a normal upshift of the control device for the automatic transmission according to the embodiment of the present invention. It is a flowchart for demonstrating the effect | action of the control apparatus of the automatic transmission concerning one Embodiment of this invention, Comprising: It is a figure explaining the change with respect to the upshift of normal transmission. FIG. 3 is a time chart showing characteristics at the time of upshifting from the 3rd speed to the 4th speed to the 5th speed of the control device for the automatic transmission according to the embodiment of the present invention, where (a) shows the throttle opening TH and (b) shows The gear ratio GR, (c) of the transmission indicates the characteristic of the hydraulic pressure command value with respect to the friction element that is engaged or released at the time of shifting. It is an example of the flowchart for demonstrating an effect | action of the control apparatus of the automatic transmission concerning one Embodiment of this invention, Comprising: It is a flowchart in the case of 6th speed-> 4th speed-> 2nd speed downshift. It is an example of the flowchart for demonstrating the effect | action of the control apparatus of the automatic transmission concerning one Embodiment of this invention, Comprising: It is a figure which shows the subroutine of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Engine 3 Torque converter 4 Double pinion type planetary gear mechanism (1st planetary gear mechanism)
5 Carrier 6 Transmission Case 7 Sun Gear 8 Inner Diameter Pinion Gear 9 Outer Diameter Pinion Gear 10 Ring Gear 11 Single Pinion Planetary Gear Mechanism (Second Planetary Gear Mechanism)
12 first sun gear 13 pinion gear 14 second sun gear 15 ring gear 16 carrier 17 output gear 18 single pinion planetary gear mechanism (third planetary gear mechanism)
19 Sun gear 20 Pinion gear 21 Ring gear 22 Carrier 23 Counter shaft 24 Differential gear 30 Bearing support part 31 Bearing support part 32 Bearing 40 A / T control unit (control means)
DESCRIPTION OF SYMBOLS 41 Vehicle speed sensor 42 Throttle sensor 43 Engine rotation sensor 44 Turbine rotation sensor 45 Inhibitor switch 46 Oil temperature sensor 101-105 Fastening piston chamber 106-110 Hydraulic control valve 111-115 Pressure switch 401 Target gear stage determination means 402 Shift control means 403 1st 1st shift control means 404 2nd shift control means 405 3rd shift control means 406 Inertia phase start detection means 407 Start timing correction means 408 End timing correction means S1 to S6 Rotating shaft
2-6 / B 2-6 brake (first friction element in 6-4-2 speed change)
3-5R / C 3-5 reverse clutch (first friction element in 3-4-5 shift)
LOW / C Low clutch (2nd friction element at 6-4-2 shift, 3rd friction element at 3-4-5 shift)
H / C high clutch (3rd friction element in 6-4-2 shift, 2nd friction element in 3-4-5 shift)
L & R / B Low and reverse brake

Claims (11)

A first friction element that is engaged at the first speed, released at the second speed achieved by the first speed, and engaged at the third speed achieved by the second speed;
A second friction element that is disengaged at the first gear, fastened at the second gear, and fastened at the third gear;
A third friction element that is engaged at the first speed, is engaged at the second speed, and is released at the third speed;
Target shift speed determining means for determining the target shift speed based on the running condition;
A first shift control means for performing a hydraulic pressure command to release the first friction element and a hydraulic pressure command to fasten the second friction element during the first shift;
A second shift control means for performing a hydraulic pressure command to engage the first friction element and releasing the third friction element during the second shift;
Inertia phase start detection means for detecting the start of the inertia phase;
When the target shift stage is changed from the second shift stage to the third shift stage after the start of the inertia phase is detected by the inertia phase detection start means during the execution of the first shift, the first shift of the first shift is performed. When the first predetermined gear ratio before reaching the gear ratio at which the inertia phase ends or a parameter corresponding to the first predetermined gear ratio is reached, the second shift is started while executing the first shift. A third shift control means;
After the second shift is started, the third shift control means has a hydraulic pressure command value from the first shift control means and a hydraulic pressure command value from the second shift control means as a hydraulic pressure command value for the first friction element. A control device for an automatic transmission, wherein the larger one is selected and output to the first friction element. The third shift control means immediately executes the second shift when the third shift stage is set as the target shift stage by the target shift stage determining means after the first predetermined gear ratio is reached. The control device for an automatic transmission according to claim 1, wherein the control device is executed. The first and second shift control means are control means for controlling a downshift.
When the first shift control means has a second predetermined gear ratio or a parameter corresponding to the second predetermined gear ratio, the hydraulic pressure of the first friction element is decreased to zero pressure at a first predetermined gradient. Output hydraulic pressure command value to
The third speed change control means includes end timing correction means for correcting the hydraulic pressure command value so that a release timing of the first friction element to zero pressure by the first speed change control means is advanced. Item 3. The automatic transmission control device according to item 1 or 2 The first and second shift control means are control means for controlling an upshift.
The first shift control means outputs a command to release the hydraulic pressure of the first friction element to a zero pressure with a third predetermined gradient before the end of the first shift based on a gear ratio or a parameter corresponding thereto. With
The third shift control means prohibits the release of the first friction element to zero pressure and corrects the hydraulic pressure command value so as to maintain the hydraulic pressure of the first friction element at a hydraulic pressure equivalent to the completion of the piston stroke. The control apparatus for an automatic transmission according to claim 1 or 2, further comprising means. The second speed change control means outputs a high pressure hydraulic pressure command value when the first friction element is engaged, and then executes precharge control for holding the pressure at a low pressure and promoting piston stroke,
The automatic transmission control device according to any one of claims 1 to 4, wherein the third friction element control unit prohibits precharge control by the second shift control means. Piston stroke determination means for determining completion of the piston stroke of the first friction element, and the second shift control means is configured to switch a hydraulic pressure command value based on a determination result of the piston stroke determination means,
The said 3rd shift control means prohibits the switching of the hydraulic pressure command value based on the determination result of the said piston stroke determination means by the said 2nd shift control means, The any one of Claims 1-5 characterized by the above-mentioned. Automatic transmission control device. The second shift control means outputs a hydraulic pressure command value so as to reduce the hydraulic pressure value of the third friction element stepwise to the second hydraulic pressure value simultaneously with the start of the second shift,
As a definition of the sharing ratio of each friction element, when the input torque is set to 1, the ratio of the torque that each friction element takes charge at each gear stage is defined as follows:
The third shift control means sets the second hydraulic pressure value to the first when the share ratio of the third friction element is smaller in the second shift stage than in the first shift stage. The control apparatus for an automatic transmission according to any one of claims 1 to 6, wherein the correction is performed based on a ratio between a sharing ratio in the shift stage and a sharing ratio in the second shift stage. The end timing correction means corrects the first predetermined gradient according to a vehicle speed or / and an input torque when a parameter corresponding to the second predetermined gear ratio or the second predetermined gear ratio is reached. 4. The control device for an automatic transmission according to claim 3, wherein the first predetermined gradient is corrected so as to increase as the vehicle speed increases or as the input torque increases. The end timing correction means corrects the second predetermined gear ratio or a parameter corresponding to the second predetermined gear ratio according to the vehicle speed or / and the input torque, and the higher the vehicle speed, or the input torque 3. The automatic transmission according to claim 2, wherein the second predetermined gear ratio or a parameter corresponding to the second predetermined gear ratio is corrected to a state before the start of the first shift as the value becomes larger. Control device. The third shift control means includes a start timing correction means for correcting a first predetermined gear ratio or a predetermined parameter for starting the second shift based on a vehicle speed or / and an input torque,
The start timing correction means corrects so that the difference between the first predetermined gear ratio or the predetermined parameter and the gear ratio at which the inertia phase ends or a parameter corresponding thereto increases as the vehicle speed decreases. The control device for an automatic transmission according to any one of claims 1 to 9, wherein the difference is increased as the input torque to the machine increases. A first friction element that is engaged at the first speed, released at the second speed achieved by the first speed, and engaged at the third speed achieved by the second speed;
A second friction element that is disengaged at the first gear, fastened at the second gear, and fastened at the third gear;
A third friction element that is engaged at the first speed, is engaged at the second speed, and is released at the third speed;
Target shift speed determining means for determining the target shift speed based on the running condition;
Shift control means for starting the second shift before the end of the first shift when the target shift stage changes from the second shift stage to the third shift stage when the first shift is executed. And
The first to third friction elements are configured to be engaged when a hydraulic pressure command value from the shift control means increases and to be released when the hydraulic pressure command value decreases,
When the second shift is started before the end of the first shift, the shift control means is configured to provide a hydraulic pressure command value for the first friction element in the first shift and the first in the second shift. A control apparatus for an automatic transmission, characterized in that a hydraulic pressure command value for a friction element is compared and a larger one is selected and output to the first friction element.

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