JPS6256656A - Speed change shock reducing device for automatic speed change gear - Google Patents

Abstract

PURPOSE:To make it possible to reduce the speed change shock by adjusting a fluid pressure supplied to a fluid pressure type friction element to memorize an adjusted fluid pressure value so as to drive the fluid pressure type friction element by that pressure after that in case the fluctuation range of an output shaft torque at the time of speed change is larger than the specified value. CONSTITUTION:On the basis of an output shaft torque value of an automatic speed change gear 100, which is detected by a sensor 101, the fluctuation range of the output shaft torque in a period of speed change operation is detected by a fluctuation range detecting means 102. At a speed change operation good or bad judging means 103, it is judged whether the speed operation is good or bad on the basis of the fluctuation range of the output shaft torque, and in case the result of the judgement is bad a signal is output to a fluid pressure adjusting means 104 to adjust a fluid pressure which is supplied to a fluid pressure type friction element 105 for speed change. An adjusted fluid pressure value is memorized and after the next speed change operation this fluid pressure value is to drive the fluid pressure type friction element 105.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention can be used in automatic transmissions for vehicles, and in particular, a shift shock reduction device for automatic transmissions that can reduce shift shock. Regarding.

(Prior Art) Conventional gear shift shock reducing devices for automatic transmissions include, for example, Japanese Patent Application Laid-open No. 52-106064 and Japanese Patent Application Laid-open No. 53-85.
There is one described in No. 264.

The above-mentioned conventional device detects the output shaft torque of the automatic transmission with a lux sensor, and feeds back the detection signal of the output shaft torque so that the output shaft torque changes in accordance with a preset torque change. This attempts to reduce shift shock by controlling the fluid pressure of a hydraulic friction element for shifting.

(Problems to be Solved by the Invention) However, in the conventional device described above, the output shaft torque of the automatic transmission is detected by a torque sensor, and this detection signal is fed back, while the actual change in the output shaft torque is detected in advance. Since the configuration is such that real-time control is performed in accordance with set torque changes, if the control is performed using a digital calculation circuit such as a microcomputer, an expensive device capable of high-speed calculation is required.

In addition, due to the real-time control described above, if error components such as noise are mixed into the torque sensor output, the control accuracy will immediately decrease. A torque sensor is required.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes means shown in FIG.

The variation range detection means 102 determines the variation range of the output shaft torque during a shift operation period based on the change in the output shaft torque of the automatic transmission 100 detected by the sensor 101.

The shift operation quality determining means 103 evaluates the quality of the shift operation by processing the fluctuation range of the output shaft torque.

The fluid pressure adjusting means 104 is connected to the speed change operation quality determining means 7.
In response to the evaluation based on 03, the fluid pressure supplied to the fluid pressure type friction element 105 for shifting that constitutes the automatic transmission 100 is adjusted.

(Function) The present invention evaluates the quality of the gear shifting operation by processing the fluctuation width of the output shaft torque during gear shifting, using the fluctuation range detection means 102 and the gear shifting operation quality determining means 103.
This can be realized using a digital circuit that has a slower calculation processing time than conventional devices that feed back the detected value of the output shaft torque in real time and compare it with a preset torque change.

Further, the fluid pressure adjustment means 104 adjusts the fluid pressure of the fluid pressure type friction element 105 in response to the evaluation of the quality of the speed change operation by the speed change operation quality determination means 103.
Even if error components such as noise are mixed in the detection signal of step 1, by appropriately selecting the criteria for evaluating the quality of the gear shifting operation,
Evaluation can be performed without being affected by the error components mentioned above, which eliminates the need to use high-precision sensors.
Cost reduction can be achieved.

(Example) FIG. 2 shows the configuration of an embodiment of the present invention.

The control circuit 20 is constructed using a microcomputer or other digital circuit. In order to make the control functions easier to understand, some functional blocks are illustrated.

The information input to the control circuit 20 is the output shaft torque T of the automatic transmission (as shown in the diagram) detected by the torque sensor 10.
, the throttle opening S detected by the throttle opening sensor 11 , and the output shaft rotational speed H The rotational speed N of the output shaft of the automatic transmission detected by the sensor 12
. It is U.

The torque sensor 10 is a well-known magnetostrictive torque sensor (similar to the one described in the above-mentioned conventional publication), and the output signal is an analog signal, so the control circuit 20
The signal is converted into a digital signal by an A/D converter 30 within the unit. The output signals of the throttle opening sensor 11 and the output shaft rotation speed sensor 12 are digital signals.

The output signal output from the control circuit 20 is a drive signal for a pressure control valve 40 that controls the fluid pressure of a hydraulic friction element for gear shifting that constitutes an auxiliary transmission mechanism of an automatic transmission.

As shown in FIG. 3, the pressure limiting valve 40 is composed of a spool valve 51 and a solenoid valve 52, and is configured to control the supply pressure PL (which is the output pressure from the oil pump) supplied to the input oil path 55. is applied to the spool valve 51 as control pressure PC by the variable orifice 53 whose opening degree is adjusted by the fixed orifice 53 and the solenoid valve 52, thereby adjusting the displacement M of the spool 518. As a result, the displacement M of the spool 518 is adjusted. Output pressure Ps is adjusted. The output oil passage 56 is connected to the hydraulic oil supply passage of the hydraulic friction element.

The drive signal I given to the pressure control valve 40 from the control circuit 20 is the excitation current of the solenoid valve 52, and the drive signal
This is a pulse width modulated current signal output from the M circuit (pulse width modulation circuit) 31.

That is, by changing the ON-OFF duty ratio of the drive signal I using the PWM circuit 31, the displacement of the spool 528 of the solenoid valve 52 is adjusted, and the opening degree of the variable orifice 54 is adjusted.

As a result, the output pressure P8 is adjusted.

The control circuit 20 receives each of the above input information T. UT, 5THN
Based on this, the hydraulic pressure to be applied to the hydraulic friction element for gear shifting is determined, and control is performed to reduce the gear shifting shock.The functional structure of the system is shown in FIG. 2. It consists of numbers 21 to 26.

The shift point determining unit 21 determines throttle opening S and output H. Automatic transmission speed OUT based on car rotation speed N Determine the position.

When the gear position is determined by the shift point determining unit 21, the pressure determining unit 22 recognizes a change in the gear position, that is, when a gear shift is performed, and applies pressure to the hydraulic friction element during this gear shift. A time change in supply pressure is set in advance (this set time change in supply pressure is referred to as a "reference pressure change").

The waveform recognition unit 23 detects the output shaft torque T. Enter U,
Output shaft T during gear shifting. A significant displacement point during the change in U is detected, and the output shaft torque at the detected displacement point is determined. Then, from the output shaft torque that is pulled to the determined displacement point, the fluctuation range ΔT OUT of the output shaft torque during the shift operation period is determined.
seek.

The quality determining unit 24 determines, based on the fluctuation range Δ”OUT of the output shaft torque obtained by the waveform recognition unit 23, whether the gear shifting operation causes discomfort to the driver when one gear shifting is performed. The quality of the gear shifting operation is evaluated by determining whether such large torque fluctuations have occurred.

:[l! The storage section 25 is a memory, and stores permissible shift requirements in consideration of the amount of correction of the pressure of the friction element and the wear resistance of the friction element, according to the type of shift, the operating conditions, and the determination result of the pass/fail determining section 24. Preset data is stored as a data table so that time can be determined.

The pressure adjustment unit 26 determines the pressure change of the friction element to be applied during gear shifting based on the reference pressure change set by the pressure determination unit 22 and the pressure correction amount, and applies it to the PWM circuit 31 and the pressure control valve 40. Generates an output for forming a drive signal I.

Next, FIGS. 4 to 6 show the control circuit 20 when the control circuit 20 is configured using a microcomputer.
It is a flowchart showing the 98th period that is executed 0F. The processes shown in FIGS. 4 to 6 are a series of processes, and are repeatedly executed at predetermined time intervals. 'In the process of step 61 in Fig. 4, the throttle opening S and the output shaft rotation speed N are
Each input data of THOUT is read.

In step 62, the contents of the control mode determination flag F are determined to determine which routine to proceed to. This flag F is set by two-way data, and when roOJ, it is "1 without shifting", when it is "01", it is "shifting",
When r 10 J, it does not indicate that the shift operation is being judged. Note that when the ignition switch is turned on, the flag F is reset to "00".

If the flag F=00 is determined as a result of the determination in step 62, then the operating conditions are determined in the process of step 63, and the shift diagram stored in advance in the memory is updated in the process of step 64. Based on the above operating conditions (
It is determined whether or not the throttle opening degree S and the output H (determined by the car rotational speed N) exceed a shift point at which a shift is required.

Here, if the operating conditions become such that a shift is required, the routine is terminated without any control. If it is necessary to use or change the speed, steps 66 to 69 are performed.

In step 66, the fluid pressure to be applied to the fluid pressure type friction element for shifting during shifting is determined by lookup processing of a data table of pressure data (hereinafter referred to as "pressure data table J") stored in the memory.

The data table for the above pressure data includes the type of shift, such as [shift from -1st gear to 2nd gear], [shift from 2nd gear to 3rd gear, etc.], and operating conditions (throttle opening S and output shaft rotation speed). A plurality of cases are divided according to THOUT (N, vehicle speed, etc.), and required pressure data under each condition is stored.

In the next step 67, by lookup processing of a data table of correction amount data stored in memory (hereinafter referred to as "correction amount data table"),
A correction amount ΔP (one correction m) is obtained for the pressure data obtained in step 6, and the pressure data is corrected using this correction amount ΔP.

In step 68, the pressure data corrected in step 67 is output as a command value for the supply pressure to the friction element (this will be referred to as "pressure command value P").

This pressure command value P is supplied to the PWM circuit 31 and converted into a drive signal (2) for the pressure control valve 40. This results in
The fluid pressure supplied to the friction element is -F pressure distribution horn command value P
is equal to

By executing the processes of steps 66 to 68 above, the actual speed change operation is started. Therefore, in the next step 69, the flag F is set to "01" to indicate that "shifting is in progress".

When the speed change operation is started as described above, the process of step 11 is then executed based on the determination result of the contents of the flag F performed in step 70 of FIG.
0 and listens for the output shaft torque 'OUT data.

Then, in the next step 72, after the start of the speed change operation, a process of detecting the time point at which engagement of the friction elements is started is performed.

This is a process for determining time point 1 in FIG. This is the point at which the output shaft torque TOUT began to decrease at D speed due to changes in load due to changes in the load, etc.).

Therefore, in the process of step 72, the output shaft torque "OUT" read in step 71 is compared with the output shaft torque read in the previous process, and the output shaft torque T OUT is continuously decreased a predetermined number of times. Further, when the amount of decrease in the output shaft torque during this period is equal to or greater than a predetermined value, it is determined that there is only one person at the time when the engagement of the friction element is started.

When the engagement start time tA is detected, measurement of the shift time JK is started in step 73. This shift time JK is the elapsed time from the engagement start time tA. (Hereinafter, JK will be referred to as elapsed time J.) In the next step 74, the state of change in the output shaft torque T OUT is recognized and remarkable displacement points B and P shown in FIG. 7(a) are detected. , the output shaft torque at point B is set as the bottom torque, and the output shaft torque at point P is set as the peak torque Tp.

Point B is the point at which the output shaft torque, which once decreased due to the change in gear ratio from the engagement start time tl, starts to increase due to the release of inertial energy as the engine speed decreases. Further, point P is the point at which, after the inertial energy is released, the output shaft torque starts to move toward the output shaft torque corresponding to the changed gear/V ratio.

Therefore, the detection of the above points B and P is performed by repeatedly comparing the output shaft torque TOUT read in step 71 with the output shaft torque read in the previous process every time the routine process is performed. Based on the comparison result, the magnitude relationship between the two data values is determined when driving is performed.

That is, point B is the time tB when the direction of increase/decrease in the output shaft torque is reversed from decrease to increase after the fastening start time tA, and point P is the first time after the fastening start time tA has passed. It is determined as the time point tp when the direction of increase/decrease in the output shaft torque is reversed from increase to decrease.

Next, in step 75, processing is performed to determine the end of the gear shifting operation. This process calculates the allowable shift time JC corresponding to the operating conditions from a data table of allowable shift time data stored in memory in advance, and calculates the allowable shift time JC corresponding to the operating condition.
and the elapsed time JK, and it is determined whether or not the shift is completed based on whether JK≧Jc.

The above allowable shift time J. is set for each operating condition in consideration of the wear resistance of the friction elements, since if the sliding period of the friction elements is longer than necessary, the friction elements will wear out quickly.

When the above JK≧JQ is established and the end of the shift is detected,
Through the process of step 16, a command value signal for generating a supply pressure that changes to the pressure command value P and brings the friction element into a fully engaged or completely released state is output. That is, in the case of complete engagement, as shown in FIG.
00%, and as shown in the same figure (b'), FJ! [
The supply pressure to the element increases to the full engagement pressure. This also ends the actual gear shifting operation.

When the gear shifting operation is completed, the flag F is set to "1" in step 77.
By setting the flag to "0", the processes of steps 91 to 95 shown in FIG. 6 are thereafter executed.

The process in step 91 is a process for evaluating the quality of the shift operation by determining whether or not the current shift operation was accompanied by a large torque fluctuation that would cause a shift shock.

In this process, the difference (Tp - TB) between the bottom torque TB and the peak torque TP determined in step 74 is used as the output shaft torque T. Obtained as the fluctuation range ΔTOUT of UT,
The quality of the shift operation is evaluated based on the magnitude of this variation range ΔT OUT.

The evaluation method at this time is, for example, to determine the relationship between the fluctuation range ΔT OUT and the magnitude of the shift shock through experiments in advance, and from this result to determine the fluctuation range ΔT OUT as shown in FIG.
It is conceivable to associate evaluation values corresponding to the magnitude of TOUT and set this relationship as a data table or function.

In the next step 92. Depending on whether the evaluation value obtained in step 91 is greater than a preset reference value H3 (shown in FIG. 8), it is determined whether the gear shifting operation has been performed satisfactorily.

At this time, if it is determined that the shift operation was good, it means that the pressure data determined in steps 66 and 67 in the current shift operation was a value that does not cause a shift shock, and a flag is flagged in step 95. F is reset and the routine processing ends.

On the other hand, if it is determined that the current speed change operation was accompanied by a speed change shock, steps 93 and 94 are performed.

In step 93, in order to set the pressure correction value ΔP used in step 67 to an appropriate value, a new pressure correction value ΔP is determined corresponding to the fluctuation range ΔTOUT. This pressure correction amount ΔP is determined as follows.

As shown in FIG.
T according to the pressure command value P output in step 68 from
A drive signal I with a 1-T ratio is generated.

If the supply pressure Ps to the friction element controlled by this drive signal I is, for example, the level shown by the solid line a in FIG. 9(b), the supply pressure is too high and the engagement of the friction element is short. Output shaft torque T because it occurs rapidly in time. As shown by solid line A in FIG. 9(C), UT is
Immediately after the start of a shift, a large peak torque occurs, causing a shift shock.

On the other hand, as shown by the dashed line C in FIG. 9(b), if the supply pressure PS is too small, the engagement of the friction elements will be delayed.
As shown by the dashed line C in FIG. 9(C), the output shaft torque T OUT has a large peak torque near the end of the shift, and a shift shock also occurs.

Therefore, if the supply pressure P3 is adjusted to an appropriate pressure, as shown by the broken line in FIG. 9(b), the peak 1 to A suppressed and smooth output shaft torque change can be obtained.

Therefore, in step 93, the pressure correction amount ΔP is determined from the magnitude of the fluctuation range ΔT OUT, J5, and the interval 1 between the peak torque TP generation point [p and the shift start time to.

However, when the above interval jH is small, Fig. 9(C)
Since the output shaft torque changes as shown by the solid line A in the middle, the value corresponding to the magnitude of the fluctuation range ΔTOUT will change.
The pressure correction amount ΔP used in step 67 is subtracted to obtain a new pressure correction amount ΔP.

On the other hand, if the interval [H is long, a change in the output shaft torque as shown by the dashed line C in FIG. 9(C) will occur.
A value depending on the size of the fluctuation range ΔTOUT, or step 6
The pressure correction amount ΔP used in step 7 is increased to a new pressure correction amount ΔP.

Then, in the next step 94, the pressure correction amount ΔP newly obtained in the above step 93 is replaced with data in the correction data table determined by the operating conditions and the type of shift in the shift operation performed this time.

As a result, when shifting is performed under the same conditions from now on, the pressure correction amount Δ corrected to the appropriate value in step 94
By using P, an appropriate supply pressure that does not cause a shift shock is supplied to the friction element.

Next, as a second embodiment of the present invention, an embodiment in which the control in the first embodiment is slightly modified will be described.

That is, the process performed at step 74 in the process shown in FIG. 5 is replaced with step 80 as shown in FIG.

In this step 80, by recognizing the change in UT (calculating the increase/decrease change in the output shaft torque) under the output shaft torque shown in FIG.
Output shaft torque (hereinafter referred to as “fastening starting point torque TS”)
), the bottom torque T1, the peak torque T1, and the output shaft torque at the end of the shift (hereinafter referred to as "shift end point torque T2J") are determined.

Furthermore, this embodiment differs from the first embodiment in the method of determining whether or not the speed change operation is good or bad, which is carried out in step 91 during the process shown in FIG.

In other words, the fastening starting point torque TS obtained in step 80
, bottom torque TB, peak torque TP1, shift end point torque TE, output shaft torque at J5 during shift operation. The fluctuation rate K of UT is obtained from the following equation (1).

This fluctuation rate is a value obtained by dividing the output shaft torque fluctuation range ΔTOUT (−Tp −TB) by the average value (TS+TE)/2 of the output shaft torque between the start and end of the shift operation.

Then, the quality of the gear shifting operation is evaluated based on the magnitude of this torque fluctuation rate. This evaluation method is similar to the evaluation method performed in the first embodiment, in which the relationship between the fluctuation rate and the magnitude of the shift shock is determined in advance through experiments, and the results are as shown in FIG. 11. It is conceivable to associate evaluation values corresponding to the magnitude of the fluctuation rate and set this relationship as a data table or function.

Therefore, in the next step 92, it is determined whether the gear shifting operation was performed well by determining whether the evaluation value obtained in the step 91 is greater than a preset reference value Ks (shown in FIG. 11). Determine whether or not.

Other processes and configurations are the same as those in the first embodiment, and therefore their explanations will be omitted.

As described above, in this embodiment, the following effects can be obtained by determining the quality of the speed change operation based on the fluctuation rate K obtained by processing the fluctuation width ΔTOUT. In other words, when the engine output torque is small, the fluctuation range ΔTOU of the output shaft torque
, even if T is the same, there is almost no acceleration or deceleration, so
Even small torque fluctuations will be felt by the occupants as a shift shock.

For this reason, although it is possible to determine the quality of the shift to some extent based on the magnitude of the variation width ΔTOUT of the output shaft torque, a more appropriate determination can be made by considering the magnitude of the engine output torque described above. In other words, ΔTOUT=TP-TB is the same and corresponds to the engine output torque during gear shifting (Ts+T
If E)/2 is small, the fluctuation rate will be large, and the quality of the above-mentioned shift operation can be determined with higher accuracy.

In addition, in the above embodiment, an example was shown in which the torque sensor 10 was used as a sensor that directly detects changes in the output shaft torque of an automatic transmission, but it is also possible to indirectly detect changes using an acceleration sensor. be.

However, the use of a torque sensor has the advantage of being able to detect the time point 1A when the engagement of the friction elements actually starts, and therefore more accurately detecting the time required for shifting.

(Effects of the Invention) As explained in detail above, the present invention evaluates the quality of the gear shifting operation by processing the fluctuation range of the output shaft torque of the automatic transmission during gear shifting, thereby improving the efficiency of the conventional device. This method can be realized using a digital circuit that requires a slower calculation time than a method such as the one that feeds back the detected value of the output shaft torque in real time and compares it with a preset 1-lux change.

In addition, by adjusting the fluid pressure applied to the fluid pressure type friction element for C1 shifting in response to the evaluation of the quality of the shifting operation, error components such as noise can be detected in the detection signal of the sensor that detects changes in the output shaft torque. Even if the error component is mixed in, by appropriately selecting the criteria for evaluating the quality of the gear shifting operation, the evaluation can be made without being influenced by the above error components.

Furthermore, by performing the above evaluation based on the fluctuation width of the output shaft torque, it is possible to determine that the sensor output at one point, that is, J3 L-J when the output shaft torque is zero, is Even when there is cause C such as individual differences, variations, or drift, the quality of the gear shifting operation can be evaluated without being affected by these factors.

Therefore, in the present invention, there is no need to use a highly accurate sensor 1), and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the present invention; Fig. 2 is a block diagram partially showing the structure of the first embodiment of the present invention in functional blocks; Fig. 3 is a specific example of the pressure control valve shown in Fig. 2; FIGS. 4 to 6 are flowcharts showing the processing executed in the control circuit in FIG. 2, and FIG. 7 is a diagram showing the output shaft of the automatic transmission controlled by the device of the first embodiment. A diagram showing the changes in torque, supply pressure to the friction element, and duty ratio of the drive signal, Figure 8 is a diagram showing the correspondence between the fluctuation range used for evaluating the speed change operation and the evaluation, and Figure 9 is the diagram showing the drive signal and supply. FIG. 10 is a flowchart showing part of the processing executed by the control circuit in the second embodiment of the present invention, and FIG. 11 is a waveform diagram showing the relationship between pressure and output shaft torque. It is a figure which shows the relationship between the fluctuation rate used for evaluation, and evaluation. 100... Automatic transmission 101... Sensor 10
2... Fluctuation range detection means 103... Speed change operation quality determination means 104... Fluid pressure adjustment means 105... Fluid pressure type friction element 10... Torque sensor 11... Slot 1 to opening degree sensor F 12...Output j-axis rotation speed sensor 20...Control circuit 40...Pressure control valve T
OUT...Output @1 Herc P...Pressure command value ΔP
...Pressure correction TB...Bottom torque TP...Peak torque Ts...Fastening starting point torque TE...
・Shift end point torque ΔTOUT...(output shaft torque) variation range K...variation rate Patent applicant Nichiryu Jidosha Co., Ltd. i 1・Representative patent attorney Tokihide Sugimura 'E7i'. Figure 1 Figure 3: Pressure S Figure 8: Small - large fluctuation range ΔTcttH Figure 9: Figure 11

Claims (1)

[Claims] 1. A sensor that detects changes in the output shaft torque of an automatic transmission, and a method for determining the fluctuation range of the output shaft torque during a shift operation period based on the changes in the output shaft torque detected by the sensor. An automatic transmission is configured in accordance with the evaluation by the shift operation quality determining means, comprising: a variation width detection means to be obtained; a shift operation quality determination means for evaluating the quality of the gear shifting operation by processing the fluctuation range of the output shaft torque; 1. A shift shock reducing device for an automatic transmission, comprising: fluid pressure adjusting means for adjusting fluid pressure supplied to a fluid pressure type friction element for shifting. 2. The sensor is a torque sensor, and the gear shift operation quality determining means determines the output shaft torque T_S at the time when the engagement of the friction element starts at the time of gear shift and the time at the end of the gear shift operation based on the output of the torque sensor. Find the average value (T_S+T_E)/2 of the output shaft torque T_E at
Then, from this average value and the fluctuation range ΔT_O_U_T of the output shaft torque determined by the fluctuation range detection means, the fluctuation rate K is determined by the calculation K=ΔT_O_U_T/[(T_S+T_E)/2], and the fluctuation rate K
The shift shock reducing device for an automatic transmission according to claim 1, wherein the shift shock reducing device for an automatic transmission is characterized in that the quality of the shift operation is evaluated based on the magnitude of the shift shock.