JPH0246362A - Coupling torque capacity setting method for speed change means - Google Patents

Abstract

PURPOSE:To control a smooth speed change by setting multiple shift modes in response to the accelerator state and the speed change type at the time of a speed change and correspondingly setting the coupling torque capacity of a latter stage speed change means at the time of a speed change. CONSTITUTION:A controller 30 sets the coupling torque capacity with a hydraulic control valve 20 based on the engine torque transmitted for the latter stage of speed change means 11c-15d and the inertia torque required to make the input side rotation change characteristic the desired value at the time of the power-on up-shift or the power-off down-shift from the signal of a throttle opening sensor 33 and the position of a shift lever 45. On the other hand, the input/output rotating speed ratio of a latter stage speed change means is detected from signals of rotation sensors 32 and 35 for the power-on down-shift or the power-off up-shift, the coupling torque capacity is reduced after the start of a speed change until the preset rotating speed ratio is attained, then an increased value is set. A smooth speed change with no blow-up of the engine rotation is performed.

Description

Detailed Description of the Invention A.9 Objective of the Invention (Field of Industrial Application) The present invention provides an automatic transmission in which a power transmission path is switched by an engagement operation of a transmission means to change gears. The present invention relates to a method for setting the engagement torque capacity of a means.

(Prior Art) Automatic transmissions for automobiles and the like are configured to automatically change gears depending on the driving condition to obtain desired driving characteristics. For this reason, it is a good practice to have a shift map in which upshift lines and downshift lines are set for each shift based on the relationship between vehicle speed and engine output, and to perform shift control by comparing the driving conditions with this shift map. It is being said. Examples of such speed change control include, for example, Japanese Patent Application Laid-Open No. 61-1
There is one disclosed in Japanese Patent No. 89354.

The structure of an automatic transmission includes a power transmission means (for example, a plurality of gear trains) that constitutes a plurality of power transmission paths, and a plurality of transmission means (for example, a plurality of hydraulic (operating clutch) and a means (for example, a hydraulic control valve) for controlling the operation of this transmission means, and when the driving condition crosses the shift-up line or the shift-down line, the shift-up or shift-down line is activated. Issues a gear change command for downshifting, operates a solenoid valve based on this gear change command, controls the operation of a hydraulic control valve, engages and operates one of the hydraulically operated clutches,
It is common to select a power transmission path using a predetermined gear train to change gears.

When changing gears in this way, the pre-shift stage (the speed stage set by the power transmission path (gear train) that was selected until the shift command was issued) and the post-shift stage (the speed stage selected based on the shift command) Since the speed reduction ratio (gear ratio) is different from the speed set by the transmission path, it is important to control the speed change so that there is no shift shock or shift delay.

For this reason, an accumulator is connected to the hydraulic clutch that is the transmission means, and the change in the engagement torque of the rear clutch during gear shifting is made gradual, resulting in a smooth latch engagement, or the clutch hydraulic pressure of the front clutch is released. Valve (
orifice control valve, timing harness, etc.)
The clutch oil pressure is controlled in accordance with the engine output (for example, Japanese Patent Application Laid-open No. 80-211152
(see publication).

(Problem to be Solved by the Invention) However, in automatic transmissions for automobiles, etc., various speed changes are performed, and the engagement torque value of the speed change means required for each speed change is different. There has been a problem in that it is difficult to obtain desired speed change characteristics at all speed changes using only control using an orifice control valve or the like or clutch hydraulic control corresponding to engine output.

Therefore, it is an object of the present invention to provide a method for setting a desired engagement torque capacity for each shift in a transmission means so as to obtain desired shift characteristics for each shift. .

Structure of the invention (means for solving the problem) As a means for achieving the above object, the present invention includes the following:
A plurality of shift modes are set in advance according to the accelerator state and the shift type at the time of shifting, and the engagement torque capacity of the transmission means for the second gear during shifting is set corresponding to each of these shift modes. ing. Note that the accelerator state refers to the state in which the accelerator pedal is depressed or the state in which the engine throttle is opened. A state in which the engine throttle is opened due to the accelerator pedal being depressed is referred to as a power-on state, and the opposite is referred to as a power-off state. . Furthermore, the shift type refers to whether the shift is an upshift or a downshift.

In the above case, if the accelerator state is power-on and the shift type is upshift, or if the accelerator is power-off and the shift type is downshift, the transmission is transmitted from the engine to the rear gear shifting means. The engagement torque capacity of the rear gear transmission means is set based on the engine torque to be applied and the inertia torque required to make the input side rotation change characteristic of the rear gear gear changer to a desired value for the shift at this time. I try to do that. On the other hand, when the accelerator state is power-on and the shift type is downshift, or when the accelerator is power-off and the shift type is upshift, the input side and output side of the rear gear shifting means are detects the rotation speed ratio of The value is increased to a level that allows the means to engage.

(Example) Hereinafter, specific examples will be described using the drawings.

First, with reference to FIG. 1, the configuration of an automatic transmission in which gear change control is performed using the engagement torque capacity set by the method of the present invention will be explained. In this transmission AT, engine output transmitted from an output shaft 1 of the engine via a torque converter 2 is shifted by a transmission mechanism 10 having a gear train forming a plurality of power transmission paths. is output to. Specifically, the output of the torque converter 2 is output to an input shaft 3, and five sets of gear trains are arranged in parallel with each other between this input shaft 3 and a counter shaft 4 arranged parallel thereto. The speed is changed by one of the counter shafts 4 and 4.
The signal is further transmitted to the output shaft 6 via the output gear trains 5a and 5b disposed between the counter shaft 4 and the output shaft 6.

The five gear trains disposed between the input shaft 3 and the counter shaft 4 are a 1st speed gear train 11a, llb, a 2nd speed gear train 12a, 12b, a 3rd speed gear train 13a, 13b and
4th gear train 14a, 14b and reverse gear train 15
a, 15 b + 15 c, and each gear train includes a hydraulically operated clutch 11C + 12 c, 13 c, for transmitting power by the gear train.
14c and 15d are provided. In addition,
A one-way clutch lid is disposed in the first gear flb. Therefore, by selectively operating these hydraulically operated clutches, it is possible to select power transmission by any one of the five gear trains to perform a speed change.

The operation control of the five sets of hydraulically operated clutches llc to 15d is carried out from a hydraulic control valve 20 to a hydraulic line 21.
This is done by hydraulic pressure supplied and discharged via a to 21e.

The hydraulic control valve 20 is operated by operating a manual valve 25 connected via a wire 45a to a shift lever 45 operated by the driver, operating two solenoid valves 22 and 23, and operating a linear solenoid valve 56. Ru.

The solenoid valves 22.23 are connected to the signal lines 3la, 3
The linear solenoid valve 56 is turned on and off by an operation signal sent from the controller 30 via 1b.
is activated by a signal sent from the controller 30 via the signal line 31c. A rotation signal from a first rotation sensor 35 that detects the input side rotation speed of the hydraulically operated clutch based on the rotation of the reverse gear 15c is sent to this controller 30 via a signal line 36a, and the rotation signal of the output gear 5b is sent to the controller 30. A rotation signal from the second rotation sensor 32 that detects the output side rotation speed of the hydraulically operated clutch based on the engine throttle 41 is sent via the signal line 32a.
A throttle opening signal from a throttle opening sensor 33 that detects the opening of the engine is sent via a signal line 33a.

Shift control in the transmission configured as described above will be explained.

The speed change control is performed according to a shift range set by the manual valve 25 in the hydraulic control valve 20 in response to the operation of the shift lever 45. These shift ranges include, for example, P, R, N, D, S, and 2 ranges, and in the P and N ranges, all hydraulically operated clutches 110 to 15d are disengaged and the transmission is in a neutral state. In the R range, the reverse hydraulically operated clutch 15d is engaged to set the reverse gear, and in the D, S, and 2 ranges, a shift is performed based on the shift map.

As shown in FIG. 2, this shift map has a shift-up line Lu and a shift-down line Lo as shown in the graph in which the vertical axis shows the throttle opening θTH and the horizontal axis shows the vehicle speed V. When the driving condition determined by the engine throttle opening and the vehicle speed crosses the upshift line LU toward the right side, an upshift is performed, and after the upshift, the downshift line Ln is moved toward the left side. When it crosses the road, it will downshift.

In this example, the shift performed in this manner is classified into five shift modes as described below. Note that each number corresponds to the number in the figure.

■SYU mode: A mode in which an upshift is performed when the power is off (for example, a shift up by releasing the accelerator while driving) ■SYD Motorco A mode in which a downshift is performed while the power is on (for example, a kickdown) ■IPU Mode: A mode in which an upshift is performed with the power off (e.g., an upshift during acceleration) ■IPD mode: A mode in which a downshift is performed by manual lever operation, etc. in the power off state (e.g., when the shift lever is in D) (downshift that occurs when switching from range to S range) ■EPD mode: A mode in which the vehicle speed decreases and a downshift is performed in the power-off state (for example, when the accelerator pedal is released while driving and the vehicle enters a coasting state and the vehicle speed decreases) Note that IPD mode and EPD mode are the same as far as the accelerator state and shift type are concerned, but IPD mode is used when the driver operates the lever expecting a downshift. The EPD mode is a case where automatic downshifts are performed in response to changes in driving conditions. For this reason,
In IPD mode, the tolerance level of shift shock is relatively large, but in EPD mode, this tolerance level is small. Also, depending on the car, for example, the D button and the
There is a button, and you can press the D button to set a relaxed shifting characteristic, and press the S button to set a sporty shifting characteristic, but when this button switching operation is accompanied by a power-off downshift, It is appropriate to assume that the driver did not intend to downshift, and in this case, the EPD mode is assumed.

In FIG. 2, only one shift up line and one shift down line are shown, but in reality, a plurality of each are set depending on the number of gears.

In the gear shift map shown in FIG.
An activation signal is output to the solenoid valves 22 and 23 via 1b, and the hydraulic control valve 20 is activated in response to the activation signal.
is operated, hydraulic pressure is supplied and discharged to each of the hydraulically operated clutches lie to 15d, and an upshift or downshift is performed.

This hydraulic control valve 20 will be explained with reference to FIG. 3.

In this control valve 20, hydraulic oil from the oil sump 7 supplied from the pump 8 is guided to the regulator valve 50 via the line 101.
0 to adjust the line pressure to a predetermined level. This line pressure is led to the manual valve 25 via the line 110, and as the manual valve 25 operates and the various valves in the control valve 20 operate, the line pressure is applied to the hydraulically operated clutch 11c*12ct1 for each speed stage.
It is selectively supplied to the 3C114c+15d according to the driving conditions, and the operation of each clutch is controlled.

Here, first, various valves within the control valve 20 will be explained. The check valve 52 is disposed downstream of the regulator valve 50 and prevents the oil pressure of the lubricating oil sent to the lubrication section of the transmission through the line 102 from exceeding a predetermined pressure. The modulator valve 54 reduces the line pressure sent through the line 103 to create a predetermined modulator pressure, and supplies hydraulic fluid at this modulator pressure to the torque converter 2 through the line 104.
The line 1 is supplied to a lock-up clutch control circuit (not shown) for lock-up clutch control.
05 through the first and second solenoid valves 22.2
3 for shift valve operation control.

The manual valve 25 is operated in conjunction with a shift lever 45 operated by the driver.

It is located at any one of six positions R, N, D, S, and 2, and selectively supplies line pressure from line 110 to lines 25a to 25g according to each position.

1-2 shift valve 80.2-3 shift valve 62.3
-4 shift valve 64 is similar to manual valve 25,
When in either position S or 2, the operation is controlled by the action of modulated pressure supplied via lines 106a to 106f in response to ON-OFF operation of the first and second solenoid valves 22.23. , clutch 11c+ 12ct 13c for 1st to 4th speed
This is a valve that controls the supply and discharge of line pressure to +14c.

Lines 106a and 106b are the first solenoid valve 22
and the line 10 through the orifice 22a.
Therefore, when the first solenoid valve 22 is de-energized, the port to the drain side is closed and hydraulic oil with modulated pressure is supplied from the line 105 to the lines 106a and 108b. When the energization is on, the port to the drain side is opened and the pressure in the lines 106a, 106b becomes almost zero. Moreover, the lines 106c to 10θf are connected to the second solenoid valve 23
and the line 10 through the orifice 23a.
5, and when the second solenoid valve 23 is de-energized, the port to the drain side is closed and hydraulic oil with modulated pressure is supplied from the line 105 to the lines 106c to 106f. When the power is on, the port to the drain side is opened and the line 108
The pressure from c to 106f becomes almost zero.

Here, the line 106a is connected to the right end of the 1-2 shift valve 60, and the line 108b is connected to the 2-3 shift valve 62.
The line 106c is connected to the left end of the 1-2 shift valve 60, the line 106e is connected to the right end of the 3-4 shift valve 64, and the line 106f is connected to the left end of the 2-3 shift valve 62. Note that the line 106e,
106f is manual valve 25 and line 106d
It is connected to the second solenoid valve 23 via. For this reason, the ON/OFF of the first and second solenoid valves 22゜23(7) is controlled, and each line 1゜6a to 106f is
1-2.2-3°3-4 shift valves 80, 82
．． 64, thereby controlling the line pressure supplied from the line 110 via the manual valve 25 to each hydraulically operated clutch 11c+ 12c+
It is possible to selectively supply the gear to 13c and 14c to perform a desired speed change.

This control valve 20 has first to fourth orifice control valves 70, 72, 74, and 76, and these orifice control valves control the release of the hydraulic pressure in the hydraulic chamber of the front clutch during gear shifting, and the hydraulic pressure of the rear clutch. This is done at the same time as the oil pressure in the room increases. The first orifice control pulp 70 controls the hydraulic release timing of the 3rd gear clutch when shifting from 3rd gear to 2nd gear, and the second orifice control valve 72 controls the timing of hydraulic release of the 3rd gear clutch when shifting from 2nd gear to 3rd gear or from 2nd gear to 4th gear. The hydraulic release timing of the 2nd speed clutch is controlled,
The third orifice control valve 74 controls the hydraulic release timing of the 4th gear clutch when shifting from 4th to 3rd gear or from 4th to 2nd gear, and the fourth orifice control valve 76 controls the timing of hydraulic release of the 4th gear when shifting from 3rd to 4th gear. The hydraulic release timing of the third speed clutch is controlled.

Furthermore, each hydraulically operated clutch 11 C112C113a
Accumulators 81, 82, 83, and 84 having pressure receiving chambers communicating with the hydraulic chamber of s14c are provided,
The pressure receiving chamber and piston member 81 of each of these accumulators
a + 82 a + 83 a + 84 a
Lines 121, 122.1 are connected to the back pressure chambers facing each other via
23, 124 are connected, and these lines 121,
122, 123, 124 are lines 120a, 120? )
and 120 to the linear solenoid valve 56.

The linear solenoid valve 56 is a linear solenoid valve 58
By controlling the current supplied to the linear solenoid 56a, the operating force thereof can be controlled, and the magnitude of the hydraulic pressure (pressure PTH) supplied to the line 120 can be controlled. Therefore, by controlling the current applied to the linear solenoid 56a, the oil pressure in the back pressure chamber of each of the accumulators 81 to 84 can be controlled.
Thereby, the hydraulic pressure in the hydraulic chamber of the engagement clutch can be freely controlled.

The clutch pressure control valve 78 is disposed on a line from the manual valve 25 to the 1-2 shift valve 60, and is connected to the linear solenoid valve 5.
This valve operates in response to the control pressure PTH regulated by 6.

For this purpose, each hydraulically operated clutch 11c+ 12c+ 13c, 1
The line pressure supplied to 4c is controlled by the clutch pressure control valve 78 at the control pressure PTII.
controlled accordingly. In addition, the control pressure PTH is
At times other than when shifting, the pressure is controlled to correspond to the engine output, so the line pressure for each clutch actuation should be kept as low as possible to obtain the required torque capacity corresponding to the engine output. can.

In the hydraulic control valve 20 configured as described above, each of the above-mentioned valves is appropriately operated by the operation of the manual valve 25 by operating the shift lever 45 and the on/off operation of the solenoid valve 22.23, and each hydraulically operated clutch 11C+ 12c+ 13c, 14
Selective control of supply of line pressure to C is performed, and automatic gear shifting is performed.

A method of setting the engagement torque capacity of each clutch in this automatic shifting will be described below.

Figure 4 shows the main flow of setting the engagement torque capacity.
In this setting, first, the gear change command is changed from 4th gear to 4th gear in a short time.
Confirmation of interrupt processing when successive times such as 3rd speed → 2nd speed is performed (step S1). Next, it is determined which of the five shift modes shown in FIG. 2 is the type of shift (step S2), and the engagement capacity control timing and engine output restart execution timing are determined for each of these modes. etc. (step 83).

After that, the engagement torque capacity CTQ of each clutch is calculated (step 84), and this is made to correspond to each shift mode, and the clutch engagement torque capacity during gear shifting is calculated based on the timing processing (step 83). Make settings.

In order to obtain this engagement torque capacity for each clutch, the control pressure PTH is controlled by the linear solenoid valve 56 to control the back pressure of each accumulator.
Since the piston of each accumulator is preloaded by a spring, the correction for this preload (Ao
F,, correction) is performed (step S5).

Furthermore, this A. In the P and l correction, the centrifugal oil pressure generated in the clutch oil pressure chamber due to the rotation of the clutch is also corrected.

In this way, when the desired engagement torque capacity is set and the control pressure PTH required to obtain this torque capacity is calculated, the required energization current I3 is determined from the characteristic map of the control pressure PT□ with respect to the energization current of the linear solenoid. is searched (step S6), and this current Is is output under feedback control (step S7).

Mode judgment control in the above main flow (step 8
2) will be explained in detail.

In this control, as shown in FIG.
When ODE=O, this flow ends as it is.

On the other hand, if FMODE=1, the target gear position S1 and the current gear position S are determined in step S22. If S,>SO, it is an upshift, and step 8
Proceed to 30, S, <S. is a downshift,
Proceed to step S23.

In the case of a downshift, it is determined in step S23 whether the throttle opening degree TH is smaller than the accelerator state judgment value CTH, and if TH≧CTH, it is a downshift in the power-on state, so step S27
The number “2” indicates this mode (SYD mode) in
is stored as CONTM. On the other hand, TH<CT
If H, it is a power-off downshift, but since there are two modes, IPD and EPD, it is determined whether the inhibitor switch change flag FSWCHG = O, which is set to 1 when the manual shift lever is operated. , if FSWCHG=O, it is EPD mode, so the corresponding number "5" is stored in CONTM, and FSW
If CHG=1, it is the IPD mode, so the corresponding number "4" is stored in CONTM.

On the other hand, in the case of an upshift, it is determined in step S30 whether or not the flag FSWCHG=1,
If FSWCHG=1, the process proceeds to step 833, where it is determined whether or not the judgment timer end flag FTIe, which is set when the judgment timer T1 has elapsed, is 1. If this flag F T , e=O, and the determination timer is within the set time, the mode flag FMODE is set to 1 in step S34, and the current flow is ended.

When FSWCHG=O, throttle opening change rate D
It is determined whether THM is smaller than the SYU mode threshold value DTH8Y (Step 531), DTHM≧DTH8
In the case of Y, it is a power-on fist upshift and IPU
It is determined that the mode is selected, and the number "3" corresponding to this is stored in CONTM.

If DTHM<DTH8Y, it is determined whether or not the judgment timer end flag FTIa=1, and this flag F T
,,=O, and within the set time of the judgment timer, the mode flag FMOD is set in step S34.
Set E to 1 and end this flow.

When this flag FTllll=0, the magnitude of the throttle opening TH and the predetermined judgment opening CTHM is compared (step 835), and when TH<CTHM, it is determined that it is a power-off upshift and SYU. Corresponding to this,
Store the number “1” in CONTM, and set TH≧CTHM.
In this case, it is determined that the power-on upshift is in IPU mode, and the corresponding number "3" is sent to the CO.
Store it in NTM.

When it is determined which of the five shift modes is selected as described above, the inhibitor switch change flag FSWCHG and the mode flag FMODE are set to 0 (steps S28 and 529), and this flow is ended.

Next, calculation of the clutch engagement torque capacity CTQ (step S4) in the main flow of FIG. 4 will be explained with reference to the flowchart of FIG. 6.

In this calculation, first, from the engine output which is preset based on the relationship between engine speed N6 and intake negative pressure Pa, the engine speed corresponding to the engine speed and intake negative pressure at that time (during gear change) is calculated. Read engine output torque ETQ (step 541). Next, during gear shifting, since engine output retardation is performed for the purpose of smooth gear shifting, the engine output is corrected by this retard (step 542). moreover,
Since the engine output is transmitted to the transmission via the torque converter, the torque amplification by the torque converter is also corrected (step 543).

When the engine torque ETQ transmitted to the transmission input shaft is calculated by the above correction, it is determined in step S44 that the current gear shift is in the inertia torque required mode (specifically, IPU and IPD modes). It is determined whether or not the inertia torque I
TQ is calculated.

Inertia torque ITQ is calculated by determining the rate of change in engine speed from the relationship between the amount of change in engine speed caused by this shift and the desired shift time required for this shift.
This refers to the torque capacity required to rotate the input side inertia of the clutch that is engaged during gear shifting in accordance with the above-mentioned rotational change rate. Therefore, this torque ITQ is calculated based on the engine rotational speed at the time of the shift, desired shift characteristics, input side inertia, etc.

In the case of the inertia torque required mode, the inertia torque ITQ calculated in step S45 is added to the engine torque ETQ to obtain the transmission input shaft torque.

Once the transmission input shaft torque is determined in accordance with each shift mode in this way, in step 84B, time and oil temperature correction (DTQ correction) at the time of oil pressure rise is performed. Even if oil pressure is supplied to the gear shift engagement clutch at the start of gear shifting, there is a time delay until the oil reaches the clutch hydraulic chamber and the clutch starts to engage. This is a correction to shorten the above time delay by increasing the hydraulic pressure supply speed to the clutch.
It is set for a predetermined time from the start of gear shifting.

However, since this time delay varies depending on the difference in oil viscosity due to the difference in oil temperature, the amount of correction thereof differs based on the oil temperature.

Since it is the transmission input shaft torque that is calculated in this way, this is converted into the torque shared by the clutch used for shifting (step 547), and the friction coefficient μ of the clutch plate in this clutch is further calculated. The latch piston pushing force required to obtain this shared torque is calculated from the relationship with the circumferential speed V (step 848).

When the required piston pushing force is calculated in this way, the required clutch oil pressure can be calculated, and the control pressure PT as the accumulator back pressure to generate this oil pressure can be calculated.
Set H. Note that the required clutch pressure is offset from this control pressure PTH by the preload of the accumulator spring, and furthermore, since the clutch is rotating, hydraulic pressure is generated in the clutch hydraulic chamber due to centrifugal force. The correction for the offset amount and the correction for the centrifugal oil pressure amount are performed in step A shown in step S5 in FIG.

, made in the amendment.

The case where the engagement torque capacity is set as described above and the gears are changed will be specifically explained for each shift mode.

First, the case of SYU mode will be explained with reference to FIG. 7A. In this case, at time t1, the shift up line LI
Cross J and go to the current gear S. When a shift command is issued from to the target gear S, the system waits for the time period T to pass.
At time t2, the shift solenoid output changes to the target gear position S.
, will be changed to In response to this output change, the engagement of the current gear clutch is released and the target gear clutch starts to be engaged, but in the SYU mode, the current gear clutch (previous gear ) is disengaged, the engine rotation changes in the direction in which the input and output rotations of the target gear clutch (rear gear gear change means) are synchronized, so the current flowing through the linear solenoid 8 is minimized at this point. , the engagement torque capacity of the rear-stage clutch is set low.

At this time, the input/output rotation speed ratio e of the clutch for the rear stage. L, is detected, and when the front clutch is released after a certain time delay after the start of the shift, this ratio e. L gradually approaches the synchronization point (the point where ec becomes 1.0). At this time, this rotation speed ratio e C! Lm is the first judgment value e cs
When reaching pu (time t4), the current I8 is increased to a value corresponding to the engine torque ETQ, and the second judgment value e is reached. c.
When reaching pu (time t6), the current Is is returned to its maximum value. As a result, the rear-stage clutch gradually starts engaging before the synchronization point and is completely engaged at the synchronization point, resulting in smooth gear shifting. In addition, in this control, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started (RK) by a certain amount, and the input/output rotation speed ratio e of the front stage clutch is changed. LO is a predetermined value e CR
The retard RK is started from time t3 when the value becomes 8 or more, and is returned to the original state (that is, RO) at time t8 when the rear-stage clutch is engaged.

Next, in the case of the SYD mode, the current gear S is set at time t, as shown in FIG. 7B. to target gear S,
When a shift command to S is issued, the shift solenoid output is immediately changed to the target gear S. In the case of SYD mode, when the engagement of the clutch for the second gear shift is released, the engine rotation changes in the direction in which the input and output rotations of the clutch for the first gear shift are synchronized, so the energizing current I s of the linear solenoid is at its minimum at this point. The engagement torque capacity of the rear-stage clutch is set low.

After the start of this shift, when the front stage clutch is released after a certain time delay, the input/output rotation speed ratio e CLa of the second stage clutch gradually reaches the synchronization point (eat, = 1.0). approach. At this time, this rotation speed ratio e. The first judgment value e. When it becomes SPD (time t3), the current I8
is increased to a value corresponding to the engine torque ETQ and reaches the second judgment value e0°PD (time t5), the current I8
is returned to its maximum value. As a result, the rear-stage clutch gradually starts engaging before the synchronization point and is completely engaged at the synchronization point, resulting in smooth gear shifting. However, if the current value is immediately returned to the maximum value from time t5, the engagement of the rear-stage clutch will become sudden and a clutch engagement shock will occur, so as shown in the figure, the rotation speed ratio e. I am trying to return it at a constant rate until L becomes 1.0.

Also, in this control, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started (RK) by a certain amount, and the input/output rotation speed ratio e CLO of the front stage clutch is Predetermined value e. The above-mentioned retard RK is started from the time t2 when the value becomes below RL. Furthermore, in order to prevent the occurrence of shock when the clutch engagement is completed, the rotation speed ratio e is adjusted. L.

e from the time when the judgment value e CRDB is reached. A retard RD larger than the retard RK is set until RDE is reached.

Further, in the case of the IPU mode, as shown in FIG. 7C, the current gear S is set at time t1. to target gear S,
When a shift command is issued, the shift solenoid output is changed to the target gear position S at time t2 after waiting for the judgment timer T to elapse. In the case of IPU mode, when the engagement of the current gear clutch (previous gear clutch) is released, the engine rotation changes in the direction in which the input/output rotation of the target gear gear clutch (rear gear clutch) moves away from the synchronization point. Therefore, it is necessary for the rear-stage clutch to start engaging immediately in order to bring the engine rotation closer to the synchronization point.

Therefore, the energizing current Is of the linear solenoid is set from this point on to a value corresponding to the combined torque of the engine torque ETQ and the inertia torque ITQ. However, even if the shift solenoid is switched, it takes time for the supplied hydraulic pressure to be sent to the rear-stage clutch, and there is a time delay until the clutch starts engaging, so from time t2 the input/output rotation speed ratio of the rear-stage clutch e ct,a Until DTQ starts to change, that is, until the rear-stage clutch starts engaging (t3), a current value corresponding to a torque DTQ larger than the above torque (ETQ+ITQ) is set, and the above time delay is shortened. . After this, the rotation speed ratio e. Ll is approximately 1.0
At time t7, the current value Is is returned to the maximum value.

In this control as well, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started by a certain amount (
RK), and the input/output rotation speed ratio of the front stage clutch is e. LO is a predetermined value e. □Time t4 when the above value is reached
The above-mentioned retard RK is started from , and the input/output rotation speed ratio e of the clutch for the second stage of gear change is determined. L is the judgment value e. RL+
From the time t5 when the judgment value e exceeds 9. Until the time when RLjll is exceeded, the retard R is larger than the above retard RK.
U is set.

In the case of IPD mode, as shown in FIG. 7D, the current gear S is set at time t1. When a shift command from S1 to the target gear S1 is issued, the shift solenoid output is immediately changed to the target gear S1. Even in the case of IPD mode, when the engagement of the current gear clutch (previous gear clutch) is released, the engine rotation changes in the direction in which the input/output rotation of the target gear gear clutch (rear gear clutch) moves away from the synchronization point. Therefore, it is necessary to start engaging the rear-stage clutch immediately.

Therefore, from this point in time t1, the energizing current Is of the linear solenoid is equal to the engine torque ETQ and the inertia torque IT.
It is set to a value corresponding to the combined torque of Q. however,
In this case as well, in order to reduce the time delay from switching the shift solenoid to the start of engagement of the rear clutch, the input/output rotation speed ratio e of the rear clutch is changed from time t1. The above torque (ETQ
+ ITQ) A current value corresponding to a larger torque DTQ is set. After this, the rotation speed ratio e. Ll is approximately 1.0
At time t8, the current value (8) is returned to the maximum value.

In this control as well, when a slip of more than a predetermined amount occurs in the engaged clutch, the engine output is started at a constant level (
RK), and the input/output rotation speed ratio of the front stage clutch is e. LO is a predetermined value e. The time t when it becomes below RL
The retard RK is started from 3, and the input/output rotational speed ratio e of the clutch for the second stage of gear change. L is the judgment value e. R1
) Judgment value e from time t5 below s. RDI! A retard RD larger than the above-mentioned retard RK is set until the time when the retard RD falls below the above retard RK.

Since the EPD mode is the same as the IPD mode in that it is a power-off downshift, its shift control is almost the same as in the IPD mode, as shown in FIG. 7E. The difference is that the linear solenoid current I
While s is a value corresponding to the sum of engine torque ETQ and inertial shuttle ITQ in IPD mode,
In the EPD mode, the value corresponds to the engine torque ETQ. As mentioned above, in the case of IPD mode, this is done based on the driver's will to downshift, so there is a strong demand for quick gear changes and a large response to the shift signal. This is because the tolerance level is relatively high, and in EPD mode, the downshift is performed automatically regardless of the driver's will, and the tolerance level for shift shock is small, so the clutch engagement is gradual and the gear is shifted. This is to reduce shock.

Note that in the SYU mode and the SYD mode, control may be performed using a value corresponding to the engine throttle opening instead of the value corresponding to the engine torque ETQ as the current value Is before engagement of the rear clutch.

As described above, optimum shift control is performed for each shift mode. Although this example shows an example in which the clutch pressure that determines the clutch engagement torque capacity is controlled using the control pressure PT11 that acts as back pressure of the accumulator, the present invention is not limited to this, and for example, , the clutch pressure may be directly controlled by a linear solenoid valve, in which case A shown in FIG. , there is no need to correct the offset of the accumulator spring in the correction. Further, the control pressure may be generated by a solenoid valve whose duty ratio is controlled, instead of by a linear adjustable valve.

As described in detail, according to the present invention, a plurality of shift modes are set in advance according to the accelerator state and the shift type at the time of shifting, and when shifting is performed in accordance with each of these shift modes. Since the engagement torque capacity of the transmission means for the latter stage of the shift is set, the optimum shift control is performed in accordance with the shift mode for each shift, and good shift control without shift shock and shift delay is achieved. You can make it happen. For example, when the accelerator state is power-on and the shift type is upshift, or when the accelerator is power-off and the shift type is downshift, the engine is transmitted from the engine to the rear gear shifting means. The engagement torque capacity of the rear-stage transmission means is set based on the torque and the inertia torque required to make the input side rotation change characteristic of the rear-stage transmission means to a desired value for the shift at this time. , when the accelerator state is power-on and the shift type is downshift, or when the accelerator is power-off and the shift type is upshift, the input side and output side of the rear gear shifting means are After the rotation speed ratio is detected and the speed change is started, the engagement torque capacity is kept low until the rotation speed ratio reaches a predetermined value, and after this reaches the predetermined value, the engagement torque capacity is reduced to a lower value. By setting the value to a value that is increased to a level where the engine speed can be engaged, smooth gear change control can be performed without engine speed spikes.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an automatic transmission in which shift control is performed using the engagement torque capacity set by the method of the present invention, and Fig. 2 is a graph showing a shift map used for shift judgment of the above-mentioned transmission. , Figure 3 is a hydraulic circuit diagram for the above-mentioned speed change control, and Figures 4 to 6 are
The figure is a flowchart showing the engagement torque capacity setting method according to the present invention, and FIGS. 7A to 7E are graphs showing the contents of the speed change control corresponding to the shift mode. 2...Torque converter 10...Transmission mechanism 20.
...Hydraulic control valve 22.23...Shift solenoid valve 25...Manual valve 32.35...Rotation sensor 56...Linear solenoid valve Fig. 2

Claims (1)

[Scope of Claims] 1) A power transmission means configuring a plurality of power transmission paths, and a plurality of speed change means for selecting the power transmission path by the power transmission means, and the speed change means according to a speed change command. In an automatic transmission that selectively engages and operates the transmission means to switch the power transmission path to perform a gear shift, an engagement torque capacity of the gear shifting means for a subsequent stage of gear shifting is set when the gear shifting command is issued. The method includes setting a plurality of shift modes according to an accelerator state and a shift type at the time of shifting, and setting an engagement torque capacity of the transmission means for the rear gear at the time of shifting, corresponding to each of these shift modes. A method for setting an engagement torque capacity of a transmission means, characterized in that: 2) If the accelerator state is a power-on state and the shift type is an upshift, or if the accelerator state is a power-off state and the shift type is a downshift, the The rear gear transmission is controlled based on the engine torque transmitted from the engine to the rear gear transmission means and the inertia torque required to set the input side rotation change characteristic of the rear gear transmission means to a desired value for the shift at this time. 2. A method for setting an engagement torque capacity of a transmission means according to claim 1, wherein the engagement torque capacity of the transmission means is set. 3) If the accelerator state is a power-on state and the shift type is a downshift, or if the accelerator state is a power-off state and the shift type is an upshift, the The rotational speed ratio between the input side and the output side of the rear-stage transmission means is detected, and after the start of shifting, the engagement torque capacity is set low until the rotational speed ratio reaches a predetermined value. 2. A method for setting an engagement torque capacity of a transmission means, wherein the engagement torque capacity is set to a value that increases the engagement torque capacity to a level at which the transmission means can be engaged after the engagement torque capacity reaches a value.