JPH03194258A - Operating oil pressure control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent a speed change shock from its change by setting operating oil pressure of a friction element at the time of a speed change basically in accordance with a throttle opening while correcting this operating oil pressure by using an intake air amount. CONSTITUTION:An automatic transmission selects a predetermined speed change shift by selectively hydraulically actuating various friction elements and performs a speed change to the other speed change shift by changing the hydraulically operated friction elements. In the case of the speed change such operated, an operating oil pressure setting means sets an operating oil pressure of the friction element at the time of the speed change basically in accordance with a throttle opening detected in a throttle opening detecting means, and this set operating oil pressure is corrected by a correcting means being based on an intake air amount detected in an intake air amount detecting means. The operating oil pressure, thus set at the time of the speed change, is made self- correctable in a relation to a change of an engine output, and dispersion of speed change quality can be decreased by preventing a speed change shock from its change.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic pressure control device for an automatic transmission, and particularly to a device for controlling hydraulic pressure during gear shifting.

(Prior art) Automatic transmissions are equipped with various frictional elements (clutches, brakes, etc.) as described in the rRE4RO3Δ type automatic transmission maintenance manual J (A261C10) published by Nichiwa Jidosha Co., Ltd. in March 1988. A corresponding gear position is selected by selective hydraulic actuation, and the gear position is automatically shifted to another gear position by changing the hydraulically actuated friction element.

Vehicles equipped with automatic transmissions transmit engine power to the drive wheels at the gear ratio of the selected gear, driving the wheels and enabling the vehicle to travel.

By the way, the working oil pressure (normal line pressure) of the friction element is determined by detecting the accelerator opening (throttle opening) as the engine load using the working oil pressure control as described in the above-mentioned document Middle East pages 1-29-31. By adjusting the pressure to match, the engagement capacity of the friction element is set to an appropriate value to prevent the element from slipping violently or causing a large shift shock. In pressure control, the engine driving force during a gear shift is represented by the throttle opening, and the line pressure characteristic most suitable for that gear shift is set to match this, and the optimum line pressure characteristic is temporarily selected depending on the gear shift state. By doing so, we aim to improve the shifting feeling.

(Problem to be Solved by the Invention) Although the above-mentioned line pressure control during gear shifting can reduce gear shifting shock without using an expensive boost sensor, it has the following problems. There is room for improvement. In other words, if we represent the engine driving force by the throttle opening and use this to uniquely determine the line pressure during gear shifting, and therefore the engagement force of the shift clutch, which is the engagement force of the friction element determined according to the line pressure, then even at the same throttle opening If the driving force changes, the shift shock will be affected by this and will jump out more than when it is in the matching state.
Alternatively, it changes to a tendency to pull in, and the degree of this change also depends on the above-mentioned change in driving force.

This will be further explained with reference to FIG. 20. This figure is an example of a torque waveform diagram of an automatic transmission showing the influence of different shift points on shift quality. Figures (a) and (b)
, (C) both show the case of shifting under the condition that the throttle opening is constant. Here, the state shown in FIGS. 3A and 3B is a state during a shift at a normal shift point, and matching is performed in such a state.

In general, during the process of shifting, the torque pull-in point occurs once as shown in the figure.For example, when shifting from 1st to 2nd gear, this basically means There is a torque phase in which the torque decreases to a point corresponding to the second speed torque that exhibits the same value, and an inertia phase that lasts for a shift time t due to rotational changes.
The torque during the shift and after the shift changes as shown in the waveform shown in the figure. When shifting at the normal shifting point, which is the matching point mentioned above, the line pressure, and therefore the clutch oil pressure, should be adjusted so that the shifting can be achieved in an appropriate state where the clutch engagement force is neither too weak nor too strong. In other words, the pressure is adjusted to the optimum value and the gear shift is performed so that a torque waveform of the torque TQ)l during the shift relative to the torque TQB before the shift is obtained as shown in FIG.

On the other hand, if we consider a case where a vehicle speed is changed quickly (other than D range) at a vehicle speed different from the vehicle speed at the normal shifting point where matching is performed, such as manual shifting by switching the range switching lever, for example, If the gear change is performed on the vehicle speed side, the same figure (a) is shown, and in the case of the high vehicle speed side, the same figure (C) is shown.
The torque waveform will be as follows. In other words, the pre-shift torque TQB
is large on the low vehicle speed side due to the low vehicle speed, and becomes small on the high vehicle speed side due to the high vehicle speed, whereas torque during gear shifting is generally determined by oil pressure, and the oil pressure remains the same if the throttle opening is the same. Therefore, no matter which side the shift point changes to, the torque TQM during shifting is the same as that at the normal shift point and does not change.As a result, it tends to pull at low vehicle speeds and jumps out at high vehicle speeds. The torque waveform becomes somewhat strange, leading to changes in shift shock.

Therefore, in the method of determining the line pressure during gear shifting by the throttle opening, there are factors that cause the engine torque to change at the same throttle opening even when matching under certain conditions, ie, as shown in Fig. 20 (a). .

It does not have the ability to absorb or correct factors that cause fluctuations in pre-shift torque as shown in (C). Therefore, in this sense, it can be said that variations in shift quality occur, and there is still room for improvement, especially when trying to further reduce the shift shock from the standpoint of emphasizing reduction of shift shock.

The present invention improves the hydraulic pressure control based on the throttle opening as described above, appropriately sets the hydraulic pressure of the friction element during gear shifting, prevents changes in gear shifting shock, and improves the shifting feeling of the lower gear. An object of the present invention is to provide a hydraulic pressure control device for an automatic transmission that can achieve the following.

(Means for Solving the Problems) For this purpose, the hydraulic control system of the present invention, as conceptually shown in FIG. 1, selects a corresponding gear stage by selective hydraulic actuation of various friction elements, In an automatic transmission that can shift to another gear by changing the gear position and control the hydraulic pressure of a friction element during the gear shift, the automatic transmission includes an intake air amount detection means for detecting an intake air amount of an engine, and a throttle opening amount. a throttle opening detection means for detecting a throttle opening; a working oil pressure setting means for setting a working oil pressure of the friction element at the time of shifting according to the throttle opening detected by the throttle opening detecting means; and a correction means for correcting the working oil pressure based on the intake air amount detected by the intake air amount detection means.

(Function) The automatic transmission selects a predetermined gear by selectively hydraulically operating the friction elements, and shifts to other gears by changing the hydraulically operated friction elements. During such a gear shift, the working oil pressure setting means sets the working oil pressure of the friction element at the time of the gear change according to the throttle opening, and the correction means sets the working oil pressure of the friction element at the time of the gear change based on the intake air amount detected by the intake air amount detection means. Correct the working oil pressure. The hydraulic pressure set in this way during gear shifting can be self-corrected in response to changes in engine output, and this self-correction function can prevent changes in gear shift shock and reduce variations in gear shift quality.

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

FIG. 2 shows an embodiment of the hydraulic control system according to the present invention, where 1 indicates an engine and 2 indicates an automatic transmission.

The automatic transmission 2 consists of a torque converter, a transmission mechanism (gear train), and various friction elements such as clutches and brakes, and the torque converter is driven by an engine output shaft, and a pump that is also used to drive an oil pump. The automatic transmission is composed of an impeller, a turbine launch that is fluid-driven by the pump impeller and transmits power, a stake, etc. The structure of this automatic transmission is known as described in the above-mentioned literature, so a description thereof will be omitted. do.

Furthermore, the automatic transmission 2 comprises a control valve 3, which forms a shift control hydraulic circuit as described in the above-mentioned document, and which also includes a line pressure solenoid 4, a first shift solenoid 5 and a second shift solenoid. 6 will be provided. These solenoids 4 to 6 are each electronically controlled by a controller 7, which receives a signal from a throttle sensor 8 that detects the throttle opening T11 (engine load) of the engine 1, and a signal from a vehicle speed sensor 9 that detects the vehicle speed V. In addition, a signal from the air flow meter 10 that detects the amount of air Qa taken into the engine 1,
A signal from a rotation sensor 11 that detects the engine rotation speed Ne and a signal from an oil temperature sensor 12 that detects the hydraulic oil temperature (ATF temperature) of the automatic transmission are input, respectively.

Here, the air flow meter 10 is constructed of, for example, a hot wire film type mass flow meter, which detects the amount of intake air, and uses the detected value for the automatic transmission (^/ (for T) is supplied to the controller 7, which is a control unit.

The controller 7 includes an input detection circuit that has functions such as converting an input analog signal into a digital signal (A/D conversion), an arithmetic processing circuit, speed change control executed by the arithmetic processing circuit, and line pressure as described below. A memory circuit that stores arithmetic programs for control, etc., and each of the shift solenoids 5 and 6.
, and a drive circuit that supplies a drive signal to the line pressure solenoid 4, which serves as a duty solenoid for duty-controlling the line pressure (none of which is shown), and shifts the speed based on each of the above-mentioned input information. control and line pressure control.

That is, the controller 7 on the one hand drives the line pressure solenoid 4 to regulate the line pressure of the automatic transmission according to the duty D determined as described later, and on the other hand controls the throttle opening TH.
and determines the gear position of the automatic transmission that is most suitable for the current driving condition from the vehicle speed V, and turns on the shift solenoid 5.6 to obtain this gear position.

Command the OFF combination. The control valve 3 is activated depending on whether these shift solenoids 5 and 6 are turned on or off.
supplies the line pressure regulated by the solenoid 4 to selected friction elements in the automatic transmission 2 as hydraulic pressure (clamping pressure), and automatically shifts the above-mentioned optimum gear by operating (clamping) these friction elements. Let the transmission choose.

The automatic transmission 2 detects the throttle opening T detected by the sensor 8.
Input the output of the engine 1 determined by H to the differential gear at a gear ratio corresponding to the selected gear position,
The vehicle can be driven by driving the left and right rear wheels through this gear.

Next, the line pressure control program shown in FIG. 3 executed by the controller 7 will be explained. This process is executed by an operating system (not shown) using regular interrupts at regular intervals.

First, in step 31, the ^TF temperature is read based on the signal from the sensor 12, and in the next step 32, it is compared with a predetermined temperature (for example, 60° C.) to determine whether this ATF temperature is low. If the temperature is lower than the predetermined temperature, in step 33, processing for line pressure control in the corresponding state, that is, line pressure control at low temperature in this case, is performed, and the line positive value obtained in this processing is A corresponding duty D is obtained in step 38, and a drive signal based on this is outputted to the line pressure solenoid 4 in step 39.

In this embodiment, the line pressure solenoid 4 is driven at <5011z (20ms cycle) as shown in FIG. 4, and the ratio of OFF time in one cycle of ON and OFF (OFF duty ratio) is controlled. By this,
The greater the duty D value, the higher the line pressure is regulated. The above-mentioned low-temperature control is as described in the above-mentioned document, so a description thereof will be omitted.

On the other hand, if it is determined that the TF temperature is equal to or higher than the predetermined temperature, the process proceeds to step 34 and subsequent steps, and a check is made as to whether or not the gear is being changed. That is, in step 34, it is determined according to the usual method whether the steady line pressure characteristic should be used or the line pressure characteristic during gear shifting should be used, and as a result, in the former case, steps 33, 38. 3
9 to perform steady line pressure control. On the other hand, in the latter case, that is, when changing gears, in the next step 35, the type of gear change, the throttle opening Tl at the time
1, the standard line pressure (the optimum line pressure corresponding to the throttle opening TH as described above, which would provide an appropriate speed change clutch engagement force under standard conditions) is determined according to the line pressure data.

That is, basically, here, the +1 line pressure value is first determined based on the line pressure data according to the throttle opening TH, and a line pressure table is used in which the required line positive value is set in advance as a function of the throttle opening TH. , look up the corresponding line positive value. Figure 5 shows step 35.
The standard line pressure PIpr, <S) is set so that it increases as the throttle opening TH value increases, with a tendency as shown in the figure. has been done.

Once the standard line pressure PI,... (S) value has been determined above, it is corrected by the intake air amount of the engine.

Here, in the following step 36, the value obtained by the calculation program is used for the intake air amount ratio, which will be described later, and the standard line pressure P1. ．． ．． (S) is corrected according to the following equation to obtain the corrected line pressure PIPrs.

PI, rs = Plpri (S) x Ko
-----(1) FIG. 6 shows an example of the above-mentioned intake air amount ratio Ka calculation routine. This subroutine is executed prior to the line pressure determination routine shown in FIG. 3, and is executed periodically at regular intervals.

First, in step 61, the throttle MjtTH is read. Regarding the throttle opening TH, A/D conversion processing (step 701) from the analog signal detected by the throttle sensor 8 is performed by the program shown in FIG. Therefore, in step 61, such A/D value is read.

Next, in step 62, the standard air amount Qa(s) is calculated. The standard air amount -(S) can be obtained from a standard air amount table in which the standard intake air amount with respect to the throttle opening TH in a standard state is tabulated in advance. FIG. 8 shows an example of this. In this example table, the parameter is the throttle opening TH, and the standard air amount Q, (s) value has the same tendency as the standard line pressure table shown in FIG. It is set corresponding to the degree T11, and in this step 62, the step 6
The corresponding Qa(S
) look up the value.

Next, in step 63, the ^/D conversion value of the intake air amount signal of the engine 1 detected by the air flow meter 10 is read. Regarding the A/D conversion value read in this step 63 as information regarding the intake air amount Oa, the detection signal of the air flow meter is determined by a program as shown in FIG. It is assumed that a /D conversion process (step 901) is being performed from an analog Qa signal, and the ^/D value obtained by this process is read in step 63.

In subsequent steps 64 and 65, an abnormality check (fail check) is performed on the intake air amount signal, and if it is abnormal, abnormality processing is performed in step 66, and the calculation is completed. As the abnormality processing (fail processing), for example,
An abnormality flag is set, and the air amount ratio used for determining the line pressure is set to a value of 1.0. With this setting, in the event of an abnormality, no correction is performed using the K value, and the line positive value PIPrs to be set is determined by searching the standard line pressure in the table shown in Figure 5 above and determining the final line pressure based on it. Based on this value, conversion to a duty value as described later and a command to the solenoid 4 are executed (steps 37 to 3 in FIG. 3).
39) Fail-safe is provided.

As will be explained later, in this line pressure control during gear shifting, the line pressure during gear shifting is essentially calculated based on the actual intake air amount (actual intake air amount) corresponding to the engine output, even under the same throttle opening condition. ) and the amount of intake air under standard conditions, that is, the standard amount of air Q, (s) obtained in advance under standard conditions, and the line pressure is made variable by comparing it and correcting the line pressure according to that ratio. However, in the event of an abnormality as described above, the data values themselves that form the basis of such control are not normal, and therefore erroneous change control is performed. Therefore, in order to avoid this, in that case, regardless of the detected value of the air flow meter, the air volume ratio as the correction coefficient will be forced to an alternative value (fail-safe value) of 1.0. It will be fixed. Since the value is fixed at 1.0, that is, no correction is made, in this case of abnormality processing, the line pressure during gear shifting is appropriately self-corrected even in response to changes in engine output, which is the target of this control. However, when the operating condition should be corrected in the direction of increasing the line pressure and therefore the clutch engagement force during gear shifting, it may be incorrect, for example, if the correction is performed in the completely opposite direction. There is no risk of erroneous control caused by excessive corrections.
Therefore, in this case, the next best option is to control the line pressure as it is in the device described in the above-mentioned literature (in the standard state, that is, in the matching state, control to the optimum value as described above is possible). Fail-safe control is realized in the sense that line pressure control (which would otherwise have been performed) is carried out.

Note that in the case of a -temporal abnormality, the self-correction function is restored after the abnormality is resolved.

On the other hand, if there is no abnormality in the determination step 65, that is, there is no abnormality in the intake air amount signal, and the intake air amount representing the output of the engine 1 is normally indicated, then it is determined from the detected actual intake air amount. Considering that it is possible to obtain a value that is properly reflected, the air amount ratio K is determined in the processing from step 67 onwards.

Execute the calculation process.

First, in step 67, the A/D value of the actual intake air amount,
That is, the read value in step 63 is converted according to the linearization characteristic of the air flow meter 10, for example, as shown in FIG. ). Above Qa
Oa for linearization with respect to values, that is, linearization processing
The calculation can be carried out by determining the corresponding value Q6 based on table data as represented by the characteristics shown in FIG. 10, which have been previously stored in the memory circuit in the controller in accordance with the airflow meter in use.

Next, in step 68, the air amount ratio is calculated according to the following formula using the Qa value and the standard air amount 0a(s) value as the read data, and furthermore, in this example, averaging processing, which will be described later, is performed. shall be taken as a thing.

K, -Qa / Qa ('') --- (2) Here, the Ka value calculated above is determined by adjusting the set line pressure PIp□ using the standard line pressure table (Fig. 5) during gear shifting.
This is a correction coefficient used to correct the standard line positive value Plprs (S) when obtaining the value, and it is calculated from the standard air amount 0a (s) and the actual intake air IQa as shown in equation (2) above. The decision to use quantitative ratios was based on the following viewpoints.

First, when focusing on the output (power) of the engine, it can be seen that the amount of intake air basically represents this, that is, the engine generates power corresponding to the amount of air. Therefore, the air flow meter 1
When the actual Oa value based on the detected value of 0 is included as a parameter, even if the throttle opening is the same, it is possible to grasp the engine output state at that point in time according to the operating state, and as will be mentioned later. Furthermore, when the engine speed decreases during gear shifting and the amount of intake air decreases accordingly, the value also changes in accordance with the decrease in the Qa value.

What is shown in FIG. 11 is the relationship between the air amount ratio and the torque ratio regarding the intake air amount of the engine. According to the figure, the torque ratio is approximately proportional to the air amount ratio. Therefore, in view of the above, the degree of difference (change) in engine torque from the standard state can be seen in terms of the air amount ratio. Therefore, if the value is calculated and the calculation process using the above formula (1) is performed as described above, then In response to changes in the output of the engine 1, the standard line pressures pz, rs(s) can be corrected to correspond to the current engine torque.

The value of the air amount ratio including the Qa value as a parameter is also effective for the following measures in the process of correcting and controlling the line pressure using this value as a correction coefficient during gear shifting. That is, when performing line pressure control during gear shifting, it may be possible to focus on the amount of fuel supplied to the engine and perform line pressure control using an amount equivalent to the fuel injection amount. In this method, the engine speed drops during gear shifting, and the value equivalent to the fuel injection amount increases as the gear shifting progresses, so the line pressure, that is, the clutch engagement force, increases as the gear shifting progresses. . Because of this, it is expected that a shock that will pop out at the end will result, and good tuning cannot be expected. Furthermore, the same behavior as above is shown when using the suction negative pressure from the boost sensor.

On the other hand, when correcting the line pressure using Qa,
Since the amount of intake air decreases as the gear shift progresses (the amount of air taken in decreases as the engine speed decreases), undesired positive feedback will not occur.

Unlike the above method, there is no problem in which the clutch engagement force gradually decreases as the gear shift progresses, and if it is determined that the clutch is engaged and the gear shift has started, the gear shift will start. It is also possible to perform control in such a way that the amount of intake air gradually decreases by the amount of decrease accompanying the decrease in the intake air amount (see FIGS. 13 to 15), which is also excellent in this respect.

Therefore, in step 69 following step 68, an averaging process, that is, a soft filtering process is executed. This is because when detecting the intake air amount, the Qa/Qa(S) value, that is, the air amount ratio which is the correction coefficient, may be affected due to fluctuations in the intake air amount or roughness of measurement during the measurement process. When the fluctuations in , are large by 1-2 times, as a result, fluctuations appear in the line pressure during gear shifting, and hence in the torque (torque during shifting), so this is done to eliminate such fluctuations. Here, the filtering process is performed by weighted averaging based on the following equation.

Ka,, -(]/4) xKa+(3/4) xKah
---(3) Here, Kah in the second term on the right side is K
, is the previous value (memorized value) for the value, and the ratio of the current calculated value obtained in step 68 in the first term to the previous value is set to an appropriate value (in this example, 174 to 3
/4), it is possible to obtain an appropriate value of the correction coefficient that is not greatly influenced by fluctuations.

In addition to the weighted average, the filtering process may also use a moving average that stores and averages the past several calculated values, and in that case, the line pressure can be corrected in the same way. Even if the Qa/Qa(S) value fluctuates greatly due to the reasons mentioned above, filtering can reduce the fluctuation and therefore reduce the influence of the fluctuation on line pressure (torque). can.

The value obtained by the above equation (3) is reset as the final air amount ratio at the current execution as 8 values, and stored in the RAM in the memory circuit in the controller.

This calculation program regarding the value is ended. The air amount ratio used for correction is thus updated one after another and is applied as the previous value for the above filtering process, while being read out as appropriate when the above-mentioned shift line pressure correction is required.

As mentioned above, when correcting the line pressure during gear shifting using the ratio between the actual intake air amount and the standard intake air amount as quasi-data, the ratio may be constantly determined and the correction may be performed using the average value. Alternatively, the ratio used for correction may be set to a value after a predetermined period of time has elapsed from the start of the shift.

Now, returning to FIG. 3, in step 36, the air amount ratio is read out as a correction value, and the standard line pressure P 1 p r s ('') value is corrected accordingly.

In the above correction, based on the relationship shown in Figure 11, if the torque change ratio is large and the intake air amount change ratio is large, the set line pressure will be correspondingly high, and if the torque change ratio is small and the air amount change ratio is small, the set line pressure will be increased accordingly. In this case, line pressure correction is performed so that the set line pressure is lowered accordingly.

In the next step 37, the return springs, etc. of the clutch system of the automatic transmission 2 are offset according to the following formula. Additionally correct FS.

Gate, , = PIFrs + PIOFS − (4)
The value obtained from the above equation is thus determined as the final line pressure.

In step 38, the maximum value of 1kPlp determined as described above should be converted into a duty value D(PI) for line pressure solenoid control according to the duty conversion table shown in FIG. 12 and output. The leaf F duty value is determined and outputted to the line pressure solenoid 4 in step 39 to drive the solenoid 4.

Since the line pressure solenoid 4 is driven and the line pressure is regulated as described above during gear shifting, Qa/Qa (s
) It is possible to change and control the line pressure during gear shifting in accordance with the value. That is, a value is determined from the standard air amount Qa(s) corresponding to the throttle opening TH and the actual intake air amount Oa to the air amount ratio corresponding to the engine torque change, and this value is used to determine the line pressure during gear shifting (therefore, the gear shifting (clutch engagement force) can be corrected, thereby obtaining an appropriate latch engagement force that changes depending on the pre-shift torque.

As shown in FIG. 20, when the line pressure (clutch engagement force) during gear shifting is uniformly determined by the throttle opening,
It lacks responsiveness to changes in the shift point, and the torque jump rate changes, which affects the shift quality.However, in the case of line pressure control by value correction, as described above, the change in the engagement force of the shift clutch Line pressure control is executed during gear shifting so that this is proportional to the pre-shift torque, and even if the magnitude of the pre-shift torque changes due to different shift points, and the degree of the change is different. However, this can also be accommodated, and changes in shift shock can be reduced, and variations in shift quality can be reduced.

=25-6- Fig. 13 is an explanatory diagram of changes in torque waveform due to change in shift point due to main line pressure control, for comparison with the torque waveform diagram in Fig. 20. Even when
It is shown that the shifting at the matching point does not tend to be too slow or too sudden.

In FIG. 13, matching is performed with a predetermined ratio relationship between the pre-shift torque TQa and the during-shift torque TQM, as shown in FIG. 13, which shows the state at a normal shift point. However, if this is the standard state and a gear shift is performed at a vehicle speed different from this normal shift point, the pre-shift torque T
As shown in Figures (a) and (C) (Figure 12 is also under the condition that the throttle opening is constant), qa increases at low vehicle speeds and decreases at high vehicle speeds; The air amount ratio used to correct the inlet pressure during gear shifting,
Since the values change in the same way, the ratio between the pre-shift torque TQB and the during-shift torque Tqi can be kept unchanged as the ratio at the normal shift point. That is, the same figure (a
) and (C), in both cases, the torque Tq during shifting
Regarding (a), the line pressure is self-corrected by the Ka value so that it increases as the pre-shift torque TQB increases and decreases as it decreases, and the ratio is kept constant. As a result, the above-mentioned FIG. 20(a).

Compared to case (C), there is no change in the torque waveform to a slightly pulling torque waveform at low vehicle speeds or a torque waveform that tends to jump at high vehicle speeds, and changes in shift shock are suppressed. It is.

Furthermore, in FIG. 13, the characteristic of the reduced portion due to the decrease in the actual intake air amount Oa during the gear shift mentioned earlier is indicated by the symbol r, and as the gear shift progresses, the torque waveform changes to a broken line at the end of the shift. This shows a decreasing trend compared to the case of . If the behavior is opposite to this at the end of the shift, that is, if it shows a tendency to gradually increase compared to the case of the broken line,
While the torque grading at the end of a shift becomes stronger, the shift line pressure control according to the present invention can of course avoid the strong torque grading at the end of a shift.
As shown in the figure, torque stepping is reduced compared to the case of the characteristic shown by the broken line, and good tuning is achieved.

In the above, self-correction in response to shift point changes has been described, but this embodiment is not limited to this, but is also applicable to environmental changes such as atmospheric pressure changes, environmental temperature changes, and even turbo time lag in turbocharged vehicles. Self-correction is also possible for influences.

Hereinafter, with reference to FIGS. 14 to 17, the influence of atmospheric pressure and environmental temperature and self-correction thereof will be explained.

First, the torque waveform diagram in FIG. 16 shows, as a comparative example, changes in the torque waveform when atmospheric pressure changes in line pressure control based on throttle opening. Figure (a) when driving at low altitudes (atmospheric pressure is 1 atm) such as normal city driving, and Figure (b) when driving at high altitudes where atmospheric pressure is lower are both at the same throttle opening. This is the torque waveform during the gear shifting process at 100°C, and matching is basically performed under the former lowland conditions. Now, when changing gears when driving in such a matching state in a situation where the atmospheric pressure is low, such as at a high altitude, the engine torque will decrease under conditions of low atmospheric pressure. As shown in FIG. 2, the pre-shift torque TQa becomes low, whereas the during-shift torque Tqx is largely determined by the oil pressure and therefore does not change even if the atmospheric pressure changes.

As a result, even if the engine is matched at low altitudes, the torque waveform changes to a slightly jumpy one at high altitudes, as shown in Figure (b). Therefore, due to the difference in atmospheric pressure, such environmental changes occur even at the same throttle opening. This appears as variations in gear shifting quality.

Further, as shown in FIG. 17, which is also shown as a comparative example, the torque waveform changes from the matching point even when the environmental temperature changes. In other words, even if matching is performed based on room temperature (see figure (b)), when the environmental temperature changes to high or low temperatures (for example, when the season changes from spring or autumn to summer or winter), the engine intake air The torque generated by the engine changes due to changes in temperature, and this causes the pre-shift torque Tq
[l is small when the temperature is high, such as in the summer, and becomes large when the temperature is low, such as in the winter. On the other hand, since the torque TQM during gear shifting is largely determined by oil pressure, it does not change even if the intake air temperature changes, and as a result, as shown in Figures (a) and (C), it tends to pull in at low temperatures and jumps out at high temperatures. The torque waveform changes to something strange.

In contrast, in this shift line pressure control, the line pressure during shift is self-corrected even in response to changes in engine output due to environmental changes such as atmospheric pressure and temperature, thereby preventing worsening of shift shock.

FIG. 14 shows the self-correction function for changes in atmospheric pressure under a constant throttle opening condition, and FIG. 15 shows the self-correction function for changes in environmental temperature, and thus engine intake air temperature. Note that the characteristic molecules in the figure are the same as those in FIG. 13.

As shown in Figure 14 (Figure 14), in the case of highlands where atmospheric pressure is low, as the atmospheric pressure decreases, air density decreases and engine torque decreases. The torque TQB before shifting is smaller than that at the matching point a). Here, the engine air meter 10 is a mass flow meter, and the actual Qa also decreases in proportion to the change in air density caused by changes in atmospheric pressure.As a result, Qa/Qa decreases in proportion to the change in the pre-shift torque TQB. Qa (s) also changes, and accordingly, the value of the air amount ratio as a correction coefficient for determining the line pressure during shifting using the standard line pressure table during shifting changes. In this way, as in the case of the self-correction of the shift point described above, line pressure control is performed by correcting the value so that as the pre-shift torque Tqi decreases, the during-shift torque TQM also decreases commensurately. The ratio remains constant.

By controlling the line pressure during gear shifting in this way, the ratio of pre-shifting torque TQB and during-shifting torque TQM can always be kept constant even when the atmospheric pressure differs, thereby reducing the influence of atmospheric pressure changes on shifting quality. Self-correction is also possible, and it is possible to avoid a torque waveform that tends to jump out as shown in FIG. 16(b), thereby preventing the shift shock from worsening.

Furthermore, regarding the self-correction using a single value for changes in environmental temperature shown in FIG. 15, the effect is similar to that due to the influence of atmospheric pressure. In other words, when the air density changes depending on the environmental temperature and therefore the engine intake air temperature, the torque generated by the engine changes and the pre-shift torque TQB changes as shown in Figures (a) and (C) even under the same shifting conditions. Specifically, when the air density changes so that the torque increases due to high air density at low temperatures, and the torque decreases due to low air density at high temperatures, based on the air flow meter 10 which is a mass flow meter, The actual OaO value obtained also changes.

Therefore, the value changes in the same way as the pre-shift torque TqB changes, and therefore even if the temperature becomes lower or higher than the temperature at the matching point shown in the same figure, the pre-shift torque Tqe and the during-shift torque TQ )l ratio is kept constant, and there is no variation in the quality of shifting as in the case of FIG. 17.

In addition, in the above-mentioned self-correction based on atmospheric pressure and temperature values, the influence on line pressure control during gear shifting when a change in engine torque is caused by a change in air density is measured using the air flow meter 10, which is a mass flow meter. However, if the airflow meter used is a flap-type volumetric flowmeter, even if you use the standard line pressure table for shifting described above, it will not be possible to compensate for the effects of air density as described above. However, atmospheric pressure correction such as multiplying the line positive value PI, r obtained in step 36 of the program in FIG. Even in that case, it is possible to correct the influence of changes in air density by correcting the intake air temperature by multiplying by a predetermined correction coefficient set in advance according to The standard line pressure table can be used as is.

Furthermore, the influence of turbo time lag and correction thereof are as follows.

In engines equipped with a turbocharger, even if you suddenly press the accelerator, there is a time lag before the supercharging effect actually appears. When we consider the operating conditions in which supercharging is delayed due to such a time lag and the operating conditions in which the output is actually increased by supercharging, these two conditions have the same throttle opening and 3-4 engine speeds, but the torque is different. There is. Therefore, in the case of line pressure control during gear shifting based on throttle opening, the above-mentioned time lag causes a change in gear shifting shock. That is,
As mentioned above, there is a difference in engine torque even at the same throttle opening, so in the automatic transmission of a car equipped with a turbocharged engine, the input torque, that is, the transmitted torque, is different from when supercharging is delayed and after supercharging. This varies depending on the case, and the pre-shift torque TqB changes as explained in the shift torque waveform diagram described above. However, when determining the line pressure during gear shifting uniformly based on the throttle opening,
In the case of Fig. 20, or as explained in Fig. 16, the torque Tq)l does not change during shifting, so as a result, the torque waveform and therefore the shifting shock change, and the time lag of the turbocharger also changes due to shifting. This is the cause of variations in quality.

On the other hand, in this shift line pressure control, when the pre-shift torque TqB changes as described above, the air amount ratio Ka corresponding to the engine torque change is determined, and based on this, the line pressure during shift is adjusted. Since it is corrected, the torque Tq before shifting
It is possible to keep the ratio of n and the torque during shifting Tq)l constant both in the state where supercharging is delayed due to the turbo time lag and in the supercharged state, which reduces the variation in shift quality caused by the time lag. It can also be reduced.

FIGS. 18 and 19 show other examples of calculation of the standard intake air amount 0a(s), in which the engine rotation speed N is used as a parameter. It was also designed to be used.

That is, in a program as shown in FIG. 18(a), which is executed by an interrupt every time a pulse signal is generated from the engine rotation sensor 11, the count value C of a counter consisting of an up counter is incremented by a value l (
Step 1801) On the other hand, for a certain period of time (for example, 100m5)
) In the program shown in FIG. 5B, which is executed by a regular interrupt every cycle, each time the program is executed, the value of the counter is monitored and the engine rotation speed Ne is calculated from the count value C at the relevant time (step 1811 ), and once the pulse signals from the rotation sensor 11 have been counted and calculated for a certain period of time, the count value C is reset to 0 (that is, the counter is reset) (step 181
2).

The engine rotational speed Ne is measured as described above, and in step 62 of FIG. 6, the engine speed Ne is measured as shown in FIG. 19 based on the throttle opening TH and the read Ne value. Standard air amount Q according to the standard air amount table
Find a(s). In this standard table, the standard intake air amount for the throttle opening TH and engine speed Ne is set as characteristic data I~■, and in this example, the corresponding standard air amount Qa (
s). This is done because the intake air amount relative to the throttle opening TH actually changes when the engine speed Ne changes. Therefore, the standard air amount Qa(s) is determined using a two-dimensional table as shown in the figure. If the above-mentioned air amount ratio is calculated, it is possible to perform correction with higher accuracy.

(Effects of the Invention) Thus, as described above, the hydraulic pressure control device of the present invention basically sets the hydraulic pressure of the friction element during gear shifting according to the throttle opening, and also corrects this using the intake air amount. Therefore, it is possible to respond to changes in engine output due to factors that cause changes in shift shock, and the hydraulic pressure during the shift can be self-corrected, preventing changes in shift shock and causing variations in shift quality. It is possible to reduce the

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of the hydraulic pressure 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 flowchart of the control program of the line pressure determination routine executed by the controller on the same side. , FIG. 4 is a waveform diagram showing an example of the drive signal output for duty control of the line pressure solenoid, and FIG. 5 is a diagram showing an example of the standard line pressure table during shifting applied with the program in FIG. 3. Fig. 6 is a flowchart showing an example of a subroutine program for calculating the intake air amount ratio. Fig. 7 is a flowchart showing an A/D conversion processing program for the throttle opening signal. Fig. 8 is a standard for throttle opening. FIG. 9 is a flowchart showing an A/D conversion processing program for the air amount signal; FIG. 10 is a flowchart showing the Oa signal linearization characteristic applied to the person/D conversion value linearization processing. FIG. 11 is a diagram for explaining the relationship between air amount ratio and torque ratio. FIG. 12 is a diagram showing an example of a duty conversion table for converting line positive values into duty values. Figure 14 is a torque waveform diagram to explain the self-correction function in response to changes in shift point. Figure 14 is a torque waveform diagram to explain the self-correction function in response to changes in atmospheric pressure. Figure 15 is a torque waveform diagram to explain the self-correction function in response to environmental temperature changes. Figure 16 is a torque waveform diagram shown as a comparative example to explain the influence of atmospheric pressure. Figure 17 is a torque waveform diagram also shown as a comparative example to explain the influence of environmental temperature. Figure 18 is a torque waveform diagram shown as a comparative example to explain the influence of atmospheric pressure. A flowchart showing an example of a program for measuring the engine rotation speed Ne in another embodiment of the invention device, FIG. 19 is a diagram showing an example of a standard air amount table on the same side, and FIG. 20 is a speed change based on the throttle opening degree. FIG. 3 is a diagram showing a change in torque waveform due to a change in shift point in time line pressure control. 1...Engine 2...Automatic transmission 3...
・Control valve 4...Line pressure solenoid 5.6...Shift solenoid 7...Controller...Throttle sensor 9
...Vehicle speed sensor 10...Air flow meter 11...Engine rotation sensor 12...Oil temperature sensor <50Hz) Fig. 5-L→He formula q '1 trl-Kametoyabotan已62! ! (a) 7% 5 (llnk le'l) Fig. 14 (b) &l and C Inuzuheno F 6 lower) Fig. 16 (a) (b) High Jt (below atmospheric pressure) T#8 ( previous torque) Section (a)

Claims (1)

[Claims] 1. Selecting a corresponding gear position by selective hydraulic actuation of various friction elements, shifting to another gear position by changing the hydraulically actuated friction element, and operating the friction element at the time of the gear change. An automatic transmission capable of controlling oil pressure includes an intake air amount detection means for detecting an intake air amount of an engine, a throttle opening detection means for detecting a throttle opening, and a throttle opening detected by the throttle opening detection means. a working oil pressure setting means for setting the working oil pressure of the friction element at the time of gear shifting according to the speed; and a correction for correcting the working oil pressure at the time of shifting by the setting means based on the intake air amount detected by the intake air amount detecting means. 1. An operating hydraulic control device for an automatic transmission, comprising: means. 2. The automatic control system according to claim 1, wherein the correction means corrects the throttle opening using a ratio of standard intake air amount data and the actual intake air amount detected by the intake air amount detection means. Transmission hydraulic control device. 3. The correction means uses standard intake air amount data for throttle opening and engine speed, and performs correction based on a ratio between the standard data and the actual intake air amount detected by the intake air amount detection means. The hydraulic pressure control device for an automatic transmission according to claim 1.