JPH0242253A - Comprehensive control device for powertrain shift shock reduction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a comprehensive control device for reducing shift shock in a power train consisting of a prime mover and an automatic transmission.

(Prior art) Automatic transmissions select a predetermined gear by selectively hydraulically operating various friction elements (clutches, brakes, etc.) using line pressure, and shift to other gears by changing the activated friction elements. is possible.

However, during this shift, it is inevitable that a shift shock will occur due to the change in gear ratio. In order to reduce this shift shock, Japanese Patent Application Laid-Open No. 58-77138 proposed changing the output torque of the shift mechanism (reducing the torque during upshifts), and the applicant of the present application also previously proposed
We proposed learning control of the line pressure so that the intermediate speed time of the shift becomes the target value, and appropriately controlling the engagement capacity of the friction element that is to be operated with the line pressure during the shift.

(Problem to be solved and attempted by the invention) However, the shift is not limited to the normal shift pattern in the automatic shift driving (D) range, and even in the D range, the shift is based on a shift pattern that emphasizes fuel efficiency and acceleration. There is also a corresponding shift pattern from the D range to the second engine brake (N) range or the first engine brake (I) range. However, since it is normal to determine the line pressure learning control mode and torque change control mode for reducing the shift shock based on the shift in the D range normal pattern, which is used most frequently, the following concerns arise. Ta.

That is, the speed change pattern is as shown in FIGS. 7 and 8 at a vehicle speed of N. and the throttle opening TH to determine the gear position (1st to 4th gear in the drawing), and pass through the gear shift line (in the drawing, the upshift gear line and the downshift gear line are shown overlapping for convenience). However, as is clear from the comparison of FIGS. 7 and 8, the shift patterns are significantly different between the normal pattern and the hold pattern, for example. Therefore,
When shifting with the shift pattern changed from the normal pattern, the rotational speed and output torque of the prime mover (engine) will be different even if the speed is the same with the same throttle opening.

Nevertheless, if learning control of the same line pressure as in the normal pattern shift is continued, incorrect learning will occur due to a shift in the target shift time, which is suitable for reducing shift shock, and the essential effect of reducing shift shock in the normal pattern will not be fully achieved. Otherwise, the friction elements may wear out prematurely, and the line pressure at the time of shifting when the shifting pattern is changed becomes irregular, causing a large shift shock and causing premature wear of the friction elements.

Regarding torque change control, since the rotational speed of the original VJ machine is different when shifting in a shift pattern change state and when shifting in a normal pattern, it is difficult to change the speed when determining the end of shifting based on the speed ratio of the torque converter. The end judgment becomes inaccurate, it is difficult to time the end of the torque change with the end of the shift, and the effect of reducing the shift shock may not be achieved sufficiently, or the driving performance will be impaired due to unnecessary changes in the prime mover output torque.

The present invention prohibits line pressure learning control and torque change control when shifting in a shift pattern change state, and changes the set value of the torque converter speed ratio that contributes to determining the end of shifting during torque change control. The purpose is to eliminate concerns.

(Means for Solving the Problems) For this purpose, the device of the present invention, as conceptually shown in Fig. 1(a), consists of a prime mover and an automatic transmission, and the automatic transmission has a friction element operated by line pressure. In a power train equipped with a line pressure learning control means that learns and controls the line pressure so that the shift time becomes a target value during the shift time when the shift is changed, detecting a shift in a state where the shift pattern of an automatic transmission is changed. The system is equipped with a different pattern shift detection means, and a line pressure correction amount holding means that prohibits the line pressure learning control means from updating the line pressure correction amount during a shift in this shift pattern change state.

Further, as conceptually shown in FIG. 1(b), the device of the present invention includes a line pressure correction inhibiting means that prohibits correction of line pressure by the line pressure learning control means during gear shifting in a state where the shifting pattern is changed. This is provided in place of the pressure correction amount holding means.

Furthermore, as the concept of the device of the present invention is shown in FIG. 1 (C), it consists of an automatic transmission in which the output torque of the prime mover is manually applied through a prime mover and a torque converter. In a power train equipped with a torque changing means for changing the output torque of a prime mover during a shifting time until the end of a gear shifting that becomes a set value, an abnormal pattern shift detecting means for detecting a shift in a shift pattern changing state of an automatic transmission; The apparatus further includes a torque change prohibition means for prohibiting the torque change means from changing the prime mover output torque during a shift in a shift pattern change state.

Furthermore, as conceptually shown in FIG. 1(d), the device of the present invention is provided with a speed ratio set value changing means for changing the set value of the speed ratio when shifting in a shift pattern changing state in place of the torque change inhibiting means. It is something that

(Function) An automatic transmission selectively hydraulically operates friction elements using line pressure to select a predetermined gear, and transmits power from the prime mover at this gear. Furthermore, automatic transmissions can shift to other gears by changing the friction elements that operate. During this shift, the line pressure learning control means learns and controls the line pressure so that the shift time becomes the target value, and the engagement capacity of the friction element that is operated by the line pressure during the shift is reduced so that the shift shock is reduced. It can be controlled so that

By the way, if this shift is in a shift pattern change state, in response to a signal from the different pattern shift means that detects this, the line pressure correction amount holding means prohibits the line pressure learning control means from updating the line pressure correction amount. do. Therefore, although the target shift time for shift shock reduction is different when shifting in a shift pattern change state, it is possible to prevent erroneous learning in which the above learning control is continued as is and the line pressure correction amount is updated despite this. The shift shock reduction effect may not be achieved sufficiently without changing the essential shift pattern, or
It is possible to avoid a situation where the friction element wears out prematurely.

Further, instead of the line pressure correction amount holding means, the line pressure correction prohibiting means prohibits correction of the line pressure by learning control during a shift in a shift pattern change state.

Therefore, it is possible to prevent a large shift shock from occurring due to haphazard correction of the line pressure during the shift, or from prematurely wearing out the friction elements.

Furthermore, the torque changing means basically changes the output torque of the prime mover during the shift period from the start of the shift of the automatic transmission until the end of the shift when the speed ratio of the torque converter reaches the set value, thereby reducing the shift shock. Thus, when shifting in a shift pattern changing state, the torque change prohibiting means prohibits the torque changing means from changing the prime mover output torque in response to a signal from the different pattern shift detecting means that detects this. Therefore, when shifting with the shift pattern changed, the set speed ratio of the torque converter that indicates the end of shifting is different from when shifting without changing the shift pattern, so if the above-mentioned shift completion judgment is continued, this judgment will be incorrect. Although it is not possible to accurately time the end of the torque change at the end of the shift, by prohibiting the torque change at the time of the shift, it is possible to eliminate the occurrence of large shift shocks and adverse effects on driving performance due to the inability to time the shift. Can be done.

Also, the speed ratio setting value changing means in place of the torque change prohibiting means is as follows:
When changing gears in a shift pattern changing state, the set value of the torque converter speed ratio that contributes to determining the end of shifting is changed, and based on this, the torque changing means is caused to determine the end of shifting and perform torque change control. Therefore, even when changing gears while changing the shift pattern, the end of the shift can be determined accurately, and the torque change control can be completed in time with the end of the shift, thereby preventing the occurrence of large shift shocks and deterioration of driving performance. be able to.

(Example) Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 shows an embodiment of the present invention, in which numeral 1 represents an engine as a prime mover, and numeral 2 represents an automatic transmission.

The engine 1 is operated with the ignition timing and fuel injection amount determined by the engine control computer 3, and therefore the engine rotation speed N is stored in the computer 3.

The signal from the sensor 4 that detects the engine throttle opening TH and the signal from the sensor 5 that detects the engine throttle opening TH are manually generated.

The automatic transmission 2 receives power from the engine 1 through a torque converter 6, and transmits this power to an output shaft 7 at a gear ratio corresponding to the selected gear position, thereby allowing the vehicle to travel.

A control valve 8 is provided to control the speed change of the automatic transmission 2, and this control valve incorporates first and second shift solenoids 9, 10 and a line pressure solenoid 11.

These solenoids 9 to 11 are controlled by the automatic transmission control computer 12, and by turning on and off the shift solenoids 9 and 10 in the combinations shown in the table below, the automatic transmission 2 adjusts the friction elements (not shown) to line pressure. It is selectively hydraulically actuated and the corresponding gear can be selected.

Table 1 Note that the line pressure is controlled by changing the drive duty of the solenoid 11.

In order to perform such speed change control and line pressure duty control, the computer 12 inputs information regarding the engine rotational speed NE and throttle opening TH from the sensors 4 and 5, as well as the output shaft 70 rotational speed N. (vehicle speed), a signal related to the range manually selected by the manual lever 14 of the automatic transmission, a signal from the hold mode switch 15, and a signal from the power mode switch 16.
Input the signal from. In addition to performing the above-mentioned speed change control and line pressure control, the computer 12 also supplies a torque down signal Td to the engine control computer 3 to reduce the shift shock during the shift, and reduces the torque of the engine 1 via the computer 3. It also acts to reduce gear shift shock.

FIG. 3 is a program for the computer 12 to determine the line pressure correction amount by learning control.

However, to make it easier to understand, here we will use the engine speed N depending on the gear shift. Only the line pressure learning control during upshifts where the pressure decreases is shown. That is, first, in step 20, it is checked whether or not an upshift is in progress, and if it is not in an upshift, in this example, line pressure learning control is not performed, so in step 21, the read engine speed value N is determined.

The engine rotation speed N immediately before shifting is used to help determine when to start shifting. Close and store in memory.

During upshifting, in steps 22 to 24, it is determined whether the manual lever 14 is in the ■ range or the I range, whether the hold mode switch 15 is turned on, or whether the power mode switch 16 is turned on or not. According to this, it is checked whether an upshift is being performed in a shift pattern change state (from D range or normal mode).

If the upshift is in the D range or normal mode, the line pressure correction amount is corrected (updated) by learning control in steps 25 to 29 as follows. That is, in step 25, it is determined whether or not to start an upshift based on whether the engine rotational speed N has decreased from the engine rotational speed Neo immediately before the shift (see step 21) by more than a set value δ. If the shift has not yet started, the control is ended without updating the line pressure correction amount, and at the start of the shift, the shift time measurement timer is activated in step 26 to start measuring the shift time.

Then, in step 27, the transmission output rotation speed N is determined. Transmission input rotation speed N after shifting, which is found by multiplying by the gear ratio lA after shifting.

The ratio between ×IA and the engine speed N, NE When determining that the shift is completed based on whether or not the speed ratio has exceeded the speed ratio set value ε determined for each throttle opening TH, the above-mentioned shift time measurement timer is activated in step 28. Stop and finish measuring the shifting time. In the next step 29, based on the deviation between the shift time measured in this way and the target shift time suitable for reducing shift shock for D range and normal mode shifting, the line pressure correction amount is adjusted to reduce this deviation to 0. Fix it. This correction amount is used in another line pressure correction routine (not shown), and in this routine, the drive duty of the line pressure solenoid 11 is changed so that the line pressure is corrected by the correction amount. Thereby, the line pressure during shifting in the D range and normal mode can be learning-controlled so that the shifting time becomes the target value, and shifting shock can be reduced.

By the way, if it is determined in step 22, 23, or 24 that the shift is in a shift pattern change state, step 2
Since steps 5 to 29 are skipped, the line pressure correction amount is not updated during an upshift and is held at the current value.

Therefore, although the target shift time for reducing shift shock is different when shifting when the shift pattern is changed, it is possible to prevent erroneous learning in which the above learning control continues as it is, and the essential range and normal mode shifting can be prevented. It is possible to avoid a situation where the effect of reducing the shift shock is not sufficiently achieved or the friction element wears out prematurely.

FIG. 4 is a line pressure learning control program showing another example of the present invention. First, a step 40 checks whether or not the upshift is for performing line pressure learning control for reducing shift shock. If it is an upshift shift, it is determined in step 41 whether or not the shift is in a shift pattern change state (the same determination as steps 22 to 24 in FIG. 3), and in the D range, normal mode shift, which is not in a shift pattern change state. If so, in step 42 the line pressure is corrected by the correction amount corrected in step 29 in FIG.

If it is determined in step 41 that the shift is in a shift pattern change state, the above correction of the line pressure is not performed in step 43, as in the case where it is determined in step 40 that the shift is not an upshift shift. Therefore, when upshifting and shifting, if this is a shift in a state where the shift pattern is changed, by prohibiting line pressure learning control, it is possible to prevent the line pressure from being randomly corrected during the shift, and it is possible to prevent large shifts. There is no shock or premature wear of the friction elements.

FIG. 5 shows a book for a torque change program that reduces the output torque of the engine 1 during upshifts (torque down) to reduce shift shock, instead of using line pressure learning control as shown in FIGS. 3 and 4. In this example of application of the invention, steps similar to those in FIG. 3 are designated by the same reference numerals. In this example, during an upshift in the D range and normal mode, the torque down signal T is generated in steps 50 and 51 during the shift time until it is determined in step 25 that the shift has started, and then it is determined in step 27 that the shift has ended.

(See Figure 2) is issued to the engine control computer 3,
Reduces gear shift shock by reducing engine output torque.

Therefore, if it is determined in steps 22 to 24 that the shift is in a shift pattern change state, the above-mentioned torque reduction is inhibited by skipping steps 25, 50, 27, and 51 for upshifting and shifting. Therefore, since the speed ratio set value ε (see step 27) indicating the end of shifting is different from the D range when shifting in the shifting pattern change state and when shifting in normal mode, the shifting nucleus judgment is inaccurate and the shifting is not completed. This may cause the end of torque down to be delayed, causing a large shift shock and adverse effects on driving performance, but these situations can be avoided by prohibiting torque down.

In FIG. 6, the same problem is solved by correcting the torque converter speed ratio setting value ε for determining the end of shifting, without prohibiting torque reduction.

For this purpose, step 60 is set, and here, when shifting in a shift pattern change state (determined in the same manner as steps 22 to 24 in Fig. 5), the difference in shift point is calculated with respect to shifting in the D range normal mode. Modify the set speed ratio ε taking into consideration. Therefore, when shifting in the shift pattern change state, the step 27 is the same as when shifting in the D range or normal mode.
The end of the shift can be determined accurately, and the end of torque down can be timed to the end of the shift. Therefore, without prohibiting torque down, it is possible to synchronize the end of torque down with the end of the shift, thereby eliminating the occurrence of large shift shocks and adverse effects on driving performance due to the inability to synchronize the torque, as well as preventing torque reduction from occurring when the shift pattern is changed. During upshifts, the effect of reducing the shift shock due to torque reduction can be achieved in the same way as when shifting in the D range or normal mode.

(Effects of the Invention) Thus, according to the device of the present invention as claimed in claim 10, since the update of the line pressure correction amount by learning control is prohibited when shifting in a shift pattern change state, erroneous learning during this shifting can be prevented. As a result, it is possible to avoid a situation where the important shift shock reduction effect is not achieved in a state where the shift pattern is not changed, or where the friction elements wear out prematurely.

Further, according to the device of the present invention as set forth in claim 2, since the line pressure is prohibited from being corrected by learning control during a shift while the shift pattern is changed, the line pressure may be haphazardly corrected during the shift, resulting in a large shift shock. , it is possible to prevent premature wear of the friction elements.

Furthermore, according to the device of the present invention as set forth in claim 3, since the set value of the torque converter speed ratio for determining the end of a shift during a shift in a shift pattern changing state is different and it is not possible to accurately determine the end of a shift, a shift shock occurs at the time of the shift. Since the torque change control for reduction is prohibited, it is possible to avoid a situation in which the end of the torque change control is delayed from the shift end timing, causing a large shift shock or impairing driving performance.

Further, according to the device of the present invention as set forth in claim 4, since the set value of the torque converter speed ratio is changed at the time of shifting in the shift pattern changing state, it is possible to accurately determine the end of shifting at the time of said shifting. It is possible to time the end of torque change control. Therefore, the above-mentioned problem can be solved without prohibiting torque change control, and the effect of reducing shift shock by torque change control can also be achieved during the shift.

[Brief explanation of the drawing]

1(a) to (d) are conceptual diagrams of the integrated control device of the present invention, FIG. 2 is a system diagram showing an embodiment of the device of the present invention, and FIG. 3 is a diagram showing the automatic transmission control computer on the same side. Flowchart of the line pressure correction amount correction program to be executed; FIGS. 4 to 6 are flowcharts similar to FIG. 3 showing other examples of the present invention; FIGS. FIG. 2 is a diagram illustrating a typical speed change pattern. ■...Engine 2...Automatic transmission 3...
・Engine control computer 4...Engine rotation sensor 5...Throttle opening sensor 6...Torque converter 7...Transmission output shaft 8...
... Control valve 9 ... First shift solenoid 10 ... Second shift solenoid 11 ... Line pressure solenoid 12 ... Automatic transmission control computer 13 ... Output rotation sensor 14 ... Manual lever 15 ...Hold mode switch 16...Power mode switch

Claims (1)

[Scope of Claims] 1. Comprised of a prime mover and an automatic transmission, the automatic transmission learns and controls the line pressure to a target value during the shifting time, which is performed by changing the friction element operated by the line pressure. In a power train equipped with a line pressure learning control means as described above, a different pattern shift detection means detects a shift in a shift pattern change state of an automatic transmission, and the line pressure learning control when shifting in this shift pattern change state. 1. A comprehensive control device for reducing shift shock of a power train, comprising a line pressure correction amount holding means that prohibits updating of the line pressure correction amount by the means. 2. The power train according to claim 1, wherein a line pressure correction inhibiting means is provided in place of the line pressure correction amount holding means, which prohibits correction of the line pressure by the line pressure learning control means during gear shifting in a shift pattern changing state. Comprehensive control device for reducing shift shock. 3. It consists of a prime mover and an automatic transmission that receives the prime mover output torque via a torque converter, and the output torque of the prime mover is maintained during the shifting period from the start of shifting of the automatic transmission until the end of shifting when the speed ratio of the torque converter reaches the set value. In the power train, the power train includes a torque changing means for changing the speed of the automatic transmission, and a different pattern shift detection means for detecting a shift in a shift pattern changing state of an automatic transmission; A comprehensive control device for reducing shift shock of a power train, comprising a torque change prohibition means for prohibiting a change in torque. 4. According to claim 3, there is provided a comprehensive control system for reducing shift shock of a power train, in which a speed ratio set value changing means for changing the set value of the speed ratio when shifting in a shift pattern changing state is provided in place of a torque change inhibiting means.