JP2510308B2 - Hydraulic control system for automatic transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating hydraulic pressure control device for an automatic transmission, and more particularly to a device for controlling operating hydraulic pressure during gear shifting.

(Prior Art) As described in "RE4RO3A Type Automatic Transmission Maintenance Manual" (A261C10) issued by Nissan Motor Co., Ltd. in March 1988, various automatic transmissions such as friction elements (clutch, brake, etc.) It is configured such that the corresponding shift speed is selected by the selective hydraulic actuation, and the automatic shift to another shift speed is performed by changing the hydraulically operated friction element. Then, the vehicle equipped with the automatic transmission transmits the engine power to the drive wheels at the gear ratio at the selected gear and drives the wheels to enable the vehicle to travel.

By the way, the working oil pressure of the friction element (normal line pressure) is detected as the engine load, the accelerator opening (throttle opening) by the working oil pressure control as described on pages I-29 to 31 of the above document. By adjusting the pressure so as to match this, the engagement capacity of the friction element is made appropriate so that the element does not slip violently or the shift shock becomes large. In line pressure control, the engine drive force during a gear shift is represented by the throttle opening, and the line pressure characteristic that is most suitable for the gear shift is set to match this, and the optimum line pressure characteristic is temporarily set according to the gear shift state. By selecting it, the shift feeling is improved.

(Problems to be Solved by the Invention) Accordingly, although the above-described shift line pressure control enables reduction of shift shock without using an expensive boost sensor, the following points are required. So there is room for improvement. That is, the engine driving force is represented by the throttle opening, and the line pressure during shifting is uniquely determined by this. Therefore, when the shift clutch engagement force, which is the engagement force of the friction element determined according to the line pressure, is determined, even if the throttle opening is the same. When the driving force is changed, the shift shock is affected by this, and the shift shock tends to pop out or pull in more than in the matching state, and the degree thereof is also affected by the driving force change.

This will be further described with reference to FIG. 20, which is an example of a torque waveform diagram of the automatic transmission showing the influence on the shift quality due to different shift points. (A), (b),
(C) shows the case of gear shifting under the condition that the throttle opening is constant. Here, FIG. 11B shows a state at the time of shifting at the normal shift point, and the matching is performed in this state.

Generally, in the process of shifting, once the torque pull-in point as shown in the figure (for example, in the case of shifting from the first speed to the second speed, basically, in the second speed of the next stage, Torque phase which is approximately the same value as the torque, which is the torque equivalent point of the second speed), and the shift time t accompanying the change in rotation.
There is an inertia phase portion extending over, and the torque before the shift start, during the shift progress, and after the shift end changes in the waveform shown in the figure. Here, at the time of gear shifting at the normal gear shift point which is the matching point, the line pressure, and therefore the clutch hydraulic pressure, can be geared in an appropriate state in which the clutch engaging force is neither too weak nor too strong. That is, in order to obtain the torque waveform of the in-shift torque Tq _{M with} respect to the pre-shift torque Tq _B as shown in FIG. 7B, the pressure is adjusted to the optimum value and the shift is performed.

On the other hand, considering a case where a shift (other than the D range) is performed at a vehicle speed different from the vehicle speed at the normal shift point where matching is performed, such as a manual shift by a switching operation of the range switching lever, for example, a low shift is performed. When the gear shift is performed on the vehicle speed side, the torque waveform is as shown in FIG. 7A, and when the vehicle speed is high, the torque waveform is as shown in FIG. That is, the pre-shift torque
On the low vehicle speed side, Tq _B increases due to the low vehicle speed, and on the high vehicle speed side, it decreases due to the high vehicle speed, whereas the torque during shifting is generally determined by the hydraulic pressure. Therefore, even if the shift point changes to either side, the shifting torque Tq _M is the same as that of the normal shift point and does not change. As a result, the low vehicle speed side tends to be low and the high vehicle speed is high. On the side, the torque waveform tends to pop out, causing a shift shock change.

Therefore, in the method of determining the line pressure during shift by the throttle opening, even if matching is performed under a certain fixed condition,
The factors that cause the engine torque to change at the same throttle opening, that is, the factors that cause the pre-shift torque variation as shown in FIGS. 20 (a) and 20 (c), are absorbed or corrected. We do not have such correspondence. Therefore, in this sense, variations in shift quality occur, and it can be said that there is still room for improvement, particularly when further reduction is aimed at from the viewpoint of reducing shift shock.

The present invention improves the hydraulic pressure control by the throttle opening as described above, appropriately sets the hydraulic pressure of the friction element at the time of shifting, prevents the shift shock from changing, and further improves the shifting feeling. An object of the present invention is to provide an operating hydraulic pressure control device for an automatic transmission that can be achieved.

(Means for Solving the Problems) For this purpose, the hydraulic control system of the present invention, as shown in the concept of FIG. 1, selects a corresponding gear stage by selective hydraulic actuation of various friction elements and hydraulically operates the friction elements. In the automatic transmission capable of shifting to another shift speed by changing the value of, and controlling the hydraulic pressure of the friction element during the shift, the intake air amount detecting means for detecting the intake air amount of the engine and the throttle opening are set. Throttle opening detecting means for detecting, operating hydraulic pressure setting means for setting the operating hydraulic pressure of the friction element at the time of gear shifting according to the throttle opening detected by the throttle opening detecting means, A throttle opening detected by the throttle opening detection means for correcting the operating oil pressure based on the intake air quantity detected by the intake air quantity detection means. In addition to the standard intake air amount data, the intake air from the intake air amount detecting means for the standard intake air amount data and the standard intake air amount data obtained from the actual intake air amount detected by the intake air amount detecting means It is provided with a hydraulic oil pressure correction means for gear shifting, which corrects the hydraulic pressure during gear shifting using the intake air amount / standard intake air amount, which is the ratio of the amounts.

Further, in the above, the standard intake air amount data is the standard intake air amount data with respect to the throttle opening and the engine speed, and the ratio is obtained using the standard data.

(Operation) The automatic transmission selects a predetermined shift speed by selectively hydraulically operating the friction element, and the automatic transmission shifts to another speed by changing the friction element hydraulically operated. During such a shift, the operating oil pressure setting means sets the operating oil pressure of the friction element during a gear shift according to the throttle opening, and the operating oil pressure correction means during a gear shift is based on this, and is set to the detected intake air amount from the intake air amount detecting means. Based on the standard intake air amount data and the detected actual intake air amount, the standard intake air amount data for the throttle opening detected by the throttle opening detecting means is calculated, and Calculate the intake air amount / standard intake air amount, which is the ratio of the intake air amount from the intake air amount detecting means to the standard intake air amount data, and correct using this ratio. As a result, while the basic control is to determine the operating oil pressure during shifting of the friction element by the throttle opening, improvements can be added to this to maintain the ratio of pre-shift torque and in-shift torque constant. Can be self-corrected, and the hydraulic pressure at the time of shifting thus set can be self-corrected with respect to changes in engine output. This self-correction function prevents changes in shift shock,
Variations in shift quality can be reduced, and the basic hydraulic pressure is determined by the throttle opening, and the ratio of the intake air amount / standard intake air amount is used to correct it. In addition to being able to appropriately correct the change in the intake air amount, the hydraulic pressure of the friction element at the time of gear shifting can be set while sequentially obtaining these during gear shifting. It is also exerted during the shift, and therefore, at the time of shifting, the necessary self-correction effect as a measure for preventing shift shock change can always be obtained.

Further, in that case, as described above, not only the improvement of the method of determining the operating oil pressure during gear shifting solely depending on the throttle opening but also the determination of the operating oil pressure is performed.
It is possible to effectively perform the operating hydraulic pressure control at the time of gear shift while avoiding the shock that may occur if the fuel injection amount or the suction negative pressure is used, which may occur at the end of gear shift.

Also, the standard intake air amount data that is applied when calculating the ratio of intake air amount / standard intake air amount is used as standard intake air amount data for the throttle opening and engine speed, and is used to correct the hydraulic oil pressure during shifting. If the value of the above ratio for is calculated, it is possible to perform more accurate correction.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing.

FIG. 2 shows an embodiment of the hydraulic control system of the present invention, in which 1 is an engine and 2 is an automatic transmission.

The automatic transmission 2 includes a torque converter, a speed change mechanism (gear train), and various friction elements such as clutches and brakes. The torque converter is driven by an engine output shaft and is also used for driving an oil pump. An impeller, a turbine runner that is fluid-driven by the pump impeller to transmit power, and a stator, etc., and description of such an automatic transmission will be omitted because it is a known one described in the above document. .

Furthermore, the automatic transmission 2 comprises a control valve 3,
This control valve is provided with the line control solenoid 4, the first shift solenoid 5, and the second shift solenoid 6 as well as forming the shift control hydraulic circuit as described in the above document. Each of these solenoids 4 to 6 is electronically controlled by a controller 7, and this controller has a signal from a throttle sensor 8 for detecting a throttle opening TH (engine load) of the engine 1 and a signal from a vehicle speed sensor 9 for detecting a vehicle speed V. In addition, the signal from the air flow meter 10 that detects the amount Qa of air taken into the engine 1, the signal from the rotation sensor 11 that detects the engine speed Ne, and the hydraulic oil temperature (ATF temperature) of the automatic transmission are displayed. The signals from the oil temperature sensor 12 to be detected are input respectively.

Here, as the air flow meter 10, for example, a hot wire film type mass flow meter is used, and the intake air amount is detected by this, and the detected value is used for the automatic transmission (A / (For T) Supply to the controller 7 which is a control unit.

The controller 7 includes an input detection circuit having a function of converting an input analog signal into a digital signal (A / D conversion), an arithmetic processing circuit, a shift control executed by the arithmetic processing circuit, and a line pressure described later. A memory circuit storing a control calculation program and the like, and the shift solenoids 5 and 6,
And a drive circuit for supplying a drive signal to the line pressure solenoid 4 as a duty solenoid for duty controlling the line pressure (neither is shown), and shift control and line pressure control are performed based on the respective input information. I do.

That is, on the one hand, the controller 7 drives the line pressure solenoid 4 in accordance with the duty D determined as described later to regulate the line pressure of the automatic transmission, and on the other hand the throttle opening TH
Also, the optimum shift speed of the automatic transmission for the current driving state is determined from the vehicle speed V, and the ON / OFF combination of the shift solenoids 5 and 6 is commanded to obtain this shift speed. Control valve 3 according to ON / OFF of these shift solenoids 5 and 6
Supplies the line pressure regulated by the solenoid 4 to the selected friction elements in the automatic transmission 2 as working hydraulic pressure (engagement pressure), and automatically operates the above-mentioned optimum gear stage by the operation (engagement) of these friction elements. Let the transmission select.

The automatic transmission 2 has a throttle opening detected by the sensor 8.
The output of the engine 1 determined by TH is input to the differential gear at a gear ratio corresponding to the selected shift stage,
The vehicle can be driven by driving the left and right rear wheels via the gears.

Next, the line pressure control program of FIG. 3 executed by the controller 7 will be described. This processing is executed by a regular interrupt at regular time intervals by an operating system (not shown).

First, in step 31, the ATF 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 the ATF temperature is low. Then, when the temperature is lower than the predetermined temperature, in step 33, the line pressure control in the corresponding state, that is, in this case, the process for the line pressure control at the low temperature is performed,
The duty D corresponding to the line pressure value obtained in that process is obtained in step 38, and the drive signal based on this is obtained in step 38.
Output to line pressure solenoid 4 at 39.

In this embodiment, the line pressure solenoid 4 is driven at 50 Hz (20 ms cycle) as shown in FIG.
By controlling the ratio of OFF time in one cycle of FF (OFF duty ratio), the line pressure is adjusted higher as the duty D value increases. The above-mentioned low temperature control is the same as that described in the above-mentioned document, and therefore its explanation is omitted.

On the other hand, when it is determined that the ATF temperature is equal to or higher than the predetermined temperature, the process proceeds to step 34 and below, and it is checked whether or not gear shifting is in progress. That is, in step 34, it is determined according to a normal method whether the steady line pressure characteristic should be used or the line pressure characteristic at the time of shifting should be used,
As a result, in the former case, steps 33, 38 and 39 are executed,
Normal line pressure control is performed. On the other hand, in the latter case, that is, in the case of gear shifting, in the next step 35, the standard line pressure (the proper value in the standard state is determined from the type of gear shifting and the throttle opening TH at that time according to the line pressure data. The optimum line pressure corresponding to the throttle opening TH as described above that will obtain the shift clutch engagement force) is obtained.

That is, basically, here, the standard line pressure value is first determined by the line pressure data according to the throttle opening TH, and the line pressure table in which the required line pressure value is set in advance as a function of the throttle opening TH is set. Then, the corresponding line pressure value is looked up. FIG. 5 shows an example of the standard line pressure table at the time of shifting used in step 35,
The standard line pressure Pl _prs (S) is set to become a large value with a tendency as shown in the figure as the throttle opening TH value increases.

If the standard line pressure Pl _prs (S) value is _calculated above,
This is corrected by the intake air amount of the engine. Here, in the following step 36, the intake air amount ratio K _Q described later
The standard line pressure Pl _prs (S) is corrected according to the following equation using the K _Q value obtained by the calculation program to obtain the corrected line pressure Pl _prs .

_{Pl prs = Pl prs (S)} × K Q ---- (1) Figure 6 shows an example of the intake air amount ratio K _Q calculation routine. This subroutine is executed prior to the line pressure determination routine shown in FIG. 3 and is periodically executed at regular time intervals.

First, at step 61, the throttle opening TH is read. Regarding the throttle opening TH, an A / D conversion process (step 701) from the analog signal detected by the throttle sensor 8 is performed by a program shown in FIG. 7 which is executed by interruption every 5 ms. Therefore, in step 61, the A / D value is read.

Next, in step 62, the standard air amount Qa (S) is calculated. The standard air amount Q _Q (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 the standard state is made into a table in advance. FIG. 8 shows an example thereof. In this table example, the parameter is the throttle opening TH and the standard air amount is
The Q _a (S) value is set corresponding to the throttle opening TH with the same tendency as in the standard line pressure table of FIG. 5, and in this step 62, it corresponds to the throttle opening TH obtained in step 61. Look up the Q _a (S) value.

Next, at step 63, the A / 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 the information about the intake air amount Qa, the detection signal of the air flow meter is detected by the program shown in FIG. 9 which is executed by the interruption at every predetermined cycle (for example, 5 ms cycle). It is assumed that the A / D conversion process (step 901) from the analog Qa signal is performed and the A / D value obtained by such process is read in step 63.

In the following steps 64 and 65, an abnormality check (fail check) of the intake air amount signal is performed. If an abnormality is detected, the abnormal time process is performed in step 66 and the calculation is ended. As the abnormality processing (fail process), for example, sets the abnormality flag, and as the air amount ratio K _Q used in the line pressure determination, sets it to the value 1.0. By setting in this way, in case of abnormality, correction by K _Q value is not performed,
The line pressure value Pl _prs to be set is eventually searched for the standard line pressure in the table of FIG. 5 and the final line pressure is determined based on the standard line pressure, and based on the value, conversion into a duty value as described later, As a result of execution of the command to the solenoid 4 (see steps 37 to 39 in FIG. 3), fail safe is performed.

As will be described later, in the line pressure control during gear shifting, the line pressure during gear shifting is essentially the same as the actual intake air amount (actual intake air amount) corresponding to the output of the engine even under the same throttle opening condition. ) Is compared with the intake air amount in the standard state, that is, the standard air amount Q _a (S) previously obtained in the standard state, and the line pressure is corrected according to the ratio to make it variable. However, in the case of an abnormality as described above,
Since the data value itself which is the basis of such control is not normal, erroneous change control is performed. Therefore, in order to avoid this, in that case, the air amount ratio K _Q as the correction coefficient is forcibly fixed to a substitute value (fail safe value) of 1.0 regardless of the detected value of the air flow meter. I have decided. Since the value is fixed to 1.0, that is, the correction is not performed, in this case of abnormal processing, it is said that the line pressure during gear shifting is appropriately self-corrected even with respect to the change in the engine output targeted by this control. However, the function is lost, but the operating condition should be corrected and controlled to increase the line pressure during shifting and therefore the clutch engagement force.
For example, there is no risk of erroneous control due to improper correction such as correction in the completely opposite direction. Therefore, in this case, as a suboptimal measure, the line pressure as in the device described in the above-mentioned document is eliminated. Fail-safe control is realized in the sense that control is performed as it is (line pressure control that would be controlled to the optimum value as described above in the standard state, that is, in the matching state). It

For a temporary abnormality, the self-correction function is restored after the abnormality is resolved.

On the other hand, if it is not abnormal in the determination step 65, that is, there is no abnormality in the intake air amount signal and therefore the intake air amount representing the output of the engine 1 is in a normal state, it is determined from the detected actual intake air amount. Assuming that the value properly reflected can be obtained, the calculation process of the air amount ratio K _Q is executed in the processes from step 67 onward.

First, in step 67, the A / D value of the actual intake air amount, that is, the read value in step 63, is set to the air flow meter.
The conversion is performed according to the linearization characteristic 10 shown in FIG. 10, for example, and the value obtained by the conversion is set as the Qa value applied in step 68 described later (linearization). The linearization of the above Qa value, that is, the Qa calculation for the linearization process is based on the table data as shown in the characteristic of FIG. 10 which is stored in advance in the memory circuit in the controller according to the air flow meter used. This can be done by finding the value Q _a .

Next, at step 68, the air amount ratio _KQ is calculated according to the following equation using the Qa value and the standard air amount Qa (S) value as the read data, and further, in this example, an averaging process described later is performed. I shall.

_{K Q = Qa / Qa (S} ) ----- (2) where, K _Q values above operations, setting the line pressure Pl _prs using standard line pressure table during the shift (Figure 5) This is a correction coefficient used to correct the standard line pressure value Pl _prs (S) when obtaining the value. This is calculated from the standard air amount Qa (S) and the actual intake air amount Qa as in the above equation (2). The reason why the air amount ratio is set is based on the following viewpoints.

First, focusing on the output (power) of the engine, it can be basically considered that the intake air amount represents this, that is, it can be considered that the power corresponding to the air amount is generated in the engine. Therefore, the air flow meter
When the actual Qa value based on the detected value of 10 is included as a parameter, it is possible to grasp the engine output state at that time according to the operating state even if the throttle opening is the same condition, as will be described later. In addition, if the engine speed decreases during gear shifting and the intake air amount also decreases accordingly, K _Q
The value also changes.

FIG. 11 shows the relationship between the air amount ratio and the torque ratio for the intake air amount of the engine. According to the figure, the torque ratio is substantially proportional to the air amount ratio. Therefore, in view of the above, the degree of the difference (change) in the engine torque from the standard state can be seen by the air amount ratio. Therefore, if the K _Q value is obtained and the calculation process in the equation (1) is executed. , The standard line pressure Pl _prs (S) can be corrected to correspond to the engine torque at the present time in response to the output change of the engine 1.

The air amount ratio K _Q value including the Qa value as a parameter is also effective from the following measures in the process of correcting and controlling the line pressure by using this as a correction coefficient during gear shifting. That is, in shifting the line pressure control, it is possible to focus on the amount of fuel supplied to the engine and use the fuel injection amount equivalent to the line pressure control. In this method, the engine speed is reduced during the gear shift, and the fuel injection amount equivalent value increases as the gear shift progresses. Therefore, as the gear shift progresses, the line pressure, that is, the clutch engagement force increases. . Therefore, it is expected that a shock will pop out at the end, and good tuning cannot be expected. Also, the same behavior as above is exhibited when the suction negative pressure by the boost sensor is used.

On the other hand, when correcting the line pressure using Qa,
Since the intake air amount decreases with the progress of the gear shift (the engine rotation drops, the intake air amount decreases), so that undesired positive feedback is not applied.

There is no problem that the clutch engagement force gradually increases with the progress of the shift process like the one of the above method, and if it is determined that the clutch is engaged and the shift is started, the intake air amount during the shift It is also possible to control in such a direction that it gradually lowers by the amount of decrease due to the decrease of (see Figs. 13 to 15), which is also excellent in this respect.

Therefore, in step 69 following step 68, averaging processing, that is, soft filtering processing is executed. This is because the Qa / Qa (S) value, that is, the air amount ratio K that is the correction coefficient, is caused by fluctuations in the intake air amount, roughness of measurement in the measurement process, etc. when detecting the intake air amount. _When the fluctuation of _Q is large, as a result, the line pressure at the time of gear shift, and hence the torque (torque during gear shift), appears. Therefore, this is done in order to eliminate such fluctuation.
Here, the filtering process is performed by a weighted average based on the following equation.

K _Qn = (1/4) x K _Q + (3/4) x K _Qn --- (3) where K _{Qn in} the second term on the right side is the previous value (stored value) for the K _Q value. By setting the ratio between the _presently calculated value K _Q obtained in step 68 in the first term and the previous value K _Qn to an appropriate value (1/4 to 3/4 in this example), Therefore, it is possible to obtain a correction coefficient having an appropriate value that is not largely affected by fluctuations. In addition to the weighted average, the filtering process may use a moving average in which the past several calculated values K _Q are stored and averaged. In that case, the line pressure is similarly corrected. Qa / Qa (S)
Even if the value fluctuates greatly due to the reasons as described above, the fluctuation can be reduced by the filtering process, and therefore the influence of the fluctuation on the line pressure (torque) can be reduced.

The value obtained by the above equation (3) is reset as the final air amount ratio K _Q value at the time of this execution, stored in the RAM in the memory circuit in the controller, and the main calculation for the K _Q value is performed. Exit the program. In this way, the air amount ratio K _Q used for the correction is sequentially updated and applied as the previous value for the filtering process, while it is appropriately read when the above-mentioned shift line pressure correction is necessary.

As described above, when correcting the line pressure during shifting by the ratio of the actual intake air amount and the standard intake air amount as standard data,
The ratio may be constantly obtained and the average value may be used for the correction, or the ratio used for the correction may be a value after a predetermined time has elapsed from the start of the gear shift.

Now, returning to FIG. 3, in step 36, the air amount ratio K _Q as a correction value is read out, and the standard line pressure K
Correct the Pl _prs (S) value.

In the above correction, from the relationship of FIG. 11, if the torque change ratio is large and the intake air amount change ratio is large, the set line pressure is correspondingly increased, and the torque change ratio is small and the air amount change ratio is small. For example, the line pressure correction is performed so that the set line pressure becomes lower accordingly.

In the next step 37, the offset amount Pl _OFS of the return spring of the clutch system of the automatic transmission 2 is added and corrected according to the following equation.

Pl _prs = Pl _prs + Pl _OFS −−−− (4) Thus, the value obtained by the above equation is determined as the final line pressure. Then, in step 38, the final Pl _prs value determined as described above is converted to the duty value D (Pl) for controlling the line pressure solenoid according to the duty conversion table as shown in FIG. Obtain the duty value, and use it to determine the line pressure solenoid 4 in step 39.
To drive the solenoid 4.

Since the driving of the line pressure solenoid 4, and hence the adjustment of the line pressure, is performed as described above at the time of gear shifting, it corresponds to the Qa / Qa (S) value representing the degree of deviation of the intake air amount. It is possible to change and control the line pressure during a shift. That is, the standard air amount Qa corresponding to the throttle opening TH
From (S) and the actual intake air amount Qa, the air amount ratio _KQ value corresponding to the engine torque change is obtained, and the line pressure during shift (thus, the clutch engagement force during shift) can be corrected by this value, As a result, an appropriate clutch engagement force that changes according to the pre-shifting torque can be obtained.

As shown in FIG. 20, when the line pressure during shifting (clutch engagement force) is uniformly determined by the throttle opening,
It lacks adaptability to changes in the shift point and changes the torque jump ratio, which affects shift quality.
If correction by the line pressure control of K _Q values, per engagement force of the shift clutch, which becomes the shift line pressure control is performed so as to be proportional to the pre-shift torque, even before shifting by the shift point is different Even if the magnitude of the torque changes or the degree of the change changes, this can be dealt with, the change in the shift shock can be reduced, and the variation in the shift quality can be reduced.

FIG. 13 is an explanatory diagram of a torque waveform change accompanying a shift point change by the main line pressure control for comparison with the torque waveform diagram of FIG. 20, and even when the shift point is in a different state, As in the case of FIG. 20, the gear shift does not tend to change or tend to jump out relative to the gear shift at the matching point.

In FIG. 13, matching is performed with a predetermined ratio relationship between the pre-shift torque Tq _B and the mid-shift torque Tq _M as shown in FIG. Then, assuming that this is the standard state and gear shifting is performed at a vehicle speed different from this normal gear shift point, the pre-shift torque Tq _B is
As shown in (a) and (c) of the same figure (note that FIG. 12 also shows the condition where the throttle opening is constant), it becomes large on the low vehicle speed side and becomes small on the high vehicle speed side. The air quantity ratio K _Q value used to correct the pressure also changes, so the ratio of the pre-shift torque Tq _B to the mid-shift torque Tq _M should be the same as the ratio at the normal shift point and should not change. Is possible. That is, as shown in (a) and (c) of the same drawing, in both cases, the torque Tq _M during shifting is increased when the torque Tq _B before shifting is large, and is decreased when it is small. The line pressure is self-corrected by the _KQ value, and the ratio is kept constant. As a result, as compared with the case of FIGS. 20 (a) and 20 (c), the torque waveform may change to a pulling torque waveform on the low vehicle speed side, or may change to a jumping-out torque waveform on the high vehicle speed side. Instead, the change in shift shock is suppressed.

Further, in FIG. 13, the characteristic of the reduced portion due to the reduction of the actual intake air amount Qa during the gear shifting mentioned above is shown by a symbol r, and as the gear shifting progresses, the torque waveform shows a broken line at the end portion of the gear shifting. It tends to decrease compared with the case of. In the final stage of gear shift, when the opposite behavior is exhibited, that is, when there is a tendency to gradually increase compared to the case of the broken line, the torque step at the end of gear shift becomes stronger, whereas According to the shift line pressure control according to the present invention, it is of course possible to avoid an increase in torque step at the end of shift,
As shown in the figure, the torque step is reduced even when compared with the characteristic of the broken line, and good tuning is realized.

In the above, the self-correction for the shift point change is described, but the present embodiment is not limited to this, and may be caused by an environmental change such as a change in atmospheric pressure or a change in environmental temperature, or by a turbo time lag in a vehicle equipped with a turbocharger. Self-correction is possible even for influences.

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

First, the torque waveform diagram of FIG. 16 shows a change in the torque waveform when the atmospheric pressure changes in the line pressure control based on the throttle opening as a comparative example. The same throttle opening (a) in the case of low altitude (atmospheric pressure of 1 atm) such as normal urban driving and the same figure (b) in high altitude where atmospheric pressure is lower than that are the same. This is a torque waveform of the speed change process in degrees, and matching is basically performed under the former lowland condition. Now, when gear shifting is performed in a case where the vehicle is traveling in a situation where the atmospheric pressure is lowered such as in a highland in such a matching state, the engine torque is reduced under the condition of low atmospheric pressure. As shown in, the pre-shifting torque Tq _B becomes low, while the shifting torque Tq _M is almost determined by the hydraulic pressure and does not change even when the atmospheric pressure changes.

As a result, even if matching is performed in the lowlands, the torque waveform changes to a popping-out torque in the highlands as shown in FIG. 6B, and therefore the environmental changes that occur even at the same throttle opening due to different atmospheric pressures. It appears as variation in shift quality.

Also, as shown in FIG. 17 which is also shown as a comparative example, the torque waveform changes from that at the matching point even when the environmental temperature changes. That is, even if the matching is performed with reference to the room temperature ((b) in the figure), if the environmental temperature changes to high temperature or low temperature (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 the change in temperature, and as a result, the pre-shifting torque Tq _B becomes small when the temperature is high such as in summer, and becomes large when the temperature is low such as in winter. On the other hand, torque during shifting Tq
_{Since M} is largely determined by the hydraulic pressure, it does not change even if the intake air temperature changes, and as a result, as shown in FIGS. 7A and 7C, the torque waveform changes to a tendency that it tends to pull out at low temperatures and jump out at high temperatures. .

On the other hand, in the line pressure control during gear shifting, the line pressure during gear shifting is self-corrected even when the engine output changes due to environmental changes such as atmospheric pressure and temperature, and deterioration of gear shift shock can be prevented.

Fig. 14 shows the state of the self-correction function for atmospheric pressure changes under constant throttle opening conditions, and Fig. 15 shows the ambient temperature,
Therefore, the state of the self-correction function of the engine intake air temperature change is shown. The characteristic portion r in the figure is the same as in FIG.

In FIG. 14, as shown in FIG. 14B, in a high altitude where the atmospheric pressure is low, the air density decreases as the atmospheric pressure decreases, and the engine torque decreases. The torque Tq _B before shifting is smaller than that at the matching point in FIG. Here, the air flow meter 10 of the engine is a mass flow meter, and the actual Qa also decreases in proportion to the change in the air density caused by the change in atmospheric pressure, and as a result, Qa / Qa becomes the same as the change in the pre-shift torque Tq _B.
(S) also changes, so that the air amount ratio K _Q value as a correction coefficient for determining the line pressure during shifting also changes using the standard line pressure table during shifting. Thus, as in the case of the self-correction of the shift point described above, if the pre-shift torque Tq _B becomes smaller, the line pressure control by the correction of the K _Q value is performed so that the in-shift torque Tq _M also becomes smaller to match it.
The ratio of the two is kept constant.

By controlling the line pressure during shifting in this way, the ratio of the pre-shift torque Tq _B and the mid-shift torque Tq _M can always be kept constant even when the atmospheric pressure is different. It is also possible to self-correct the influence, and it is possible to avoid the torque waveform which tends to pop out as shown in FIG. 16 (b), and the deterioration of shift shock is prevented.

Further, the self-correction by the K _Q value with respect to the change of the environmental temperature shown in FIG. 15 is also an operation similar to the case by the influence of the atmospheric pressure. That is, in the case where the air density changes depending on the environmental temperature, that is, the engine intake air temperature, the generated torque of the engine changes, and the pre-shift torque Tq _B changes as shown in (a) and (c) even under the same shift condition, Specifically, when the air density is high and the torque is high at a low temperature, and the air density is low and the torque is low at a high temperature, the air flow meter 10 is a mass flow meter.
The value of the actual Qa obtained based on is also changed. Therefore, the change as well as K _Q value of pre-shift torque Tq _B also becomes possible to change, even at a low temperature or a temperature higher than the temperature at the matching point shown in order Fig (b), the pre-shift torque Tq _B Since the ratio of the torque Tq _M during shifting is kept constant, there is no variation in shifting quality as in the case of FIG.

In the self-correction based on the above-mentioned atmospheric pressure and temperature _KQ value, the influence on the line pressure control during shifting when the change in the torque generated by the engine is caused by the change in the air density is controlled by the air flow meter 10 which is a mass flow meter. Where it can be corrected, if the air flow meter used is a flap type volume flow meter, even if the standard line pressure table at the time of shifting described above is used, it is possible to correct the effect of the air density as described above as it is. Cannot be expected, but the line pressure value Pl obtained in step 36 of the program shown in FIG.
_{Even if the prs is subjected} to atmospheric pressure correction such as multiplication by a predetermined correction coefficient preset according to atmospheric pressure, or intake temperature correction such as multiplication by a predetermined coefficient preset according to intake temperature, even in that case The influence of the change in the air density can be corrected, and the standard line pressure table at the time of shifting shown in FIG. 5 can be used as it is.

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

With an engine equipped with a turbocharger, even if the accelerator is suddenly stepped on, there will be a time lag until the effect of supercharging actually appears. Considering an operating state in which supercharging is delayed due to such a time lag and an operating state in which supercharging is actually performed and output is increased, these differ in torque even at the same throttle opening and engine speed. Therefore, in the case of line pressure control during shifting by the throttle opening, the above-mentioned time lag causes a change in shift shock. That is, since the engine torque varies as described above even with the same throttle opening, the input torque, that is, the transmitted torque is overcharged in the automatic transmission of a vehicle equipped with a turbocharged engine and when it is delayed. In each case, the pre-shift torque Tq _B as described in the above-mentioned shift torque waveform diagram changes.
However, when uniformly determining the line pressure during shifting by the throttle opening, the torque Tq _M during shifting is not changed as in the case of FIG. 20 or as described in FIG. The waveform, and hence the shift shock, changes, and the time lag of the turbocharger also causes variations in shift quality.

On the other hand, in the line pressure control during shifting, when the pre-shifting torque Tq _B changes as described above, the air amount ratio K _Q corresponding to the engine torque change is calculated, and based on this, the shift line Since the pressure is corrected, the ratio of the pre-shift torque Tq _B to the mid-shift torque Tq _M can be kept constant even when supercharging is delayed due to the turbo time lag and during supercharging. It is also possible to reduce variations in shift quality due to time lag.

18 and 19 show another example of calculation of the standard intake air amount Qa (S), in which the engine speed N _e is also used as a parameter.

That is, in a program as shown in FIG. 18 (a) which is executed by interruption every time a pulse signal is generated from the engine rotation sensor 11, the count value C of the counter composed of an up counter is incremented by 1 (increment). (Step 1801) On the other hand, in the program of FIG. 7B which is executed by the periodic interrupt every fixed time (for example, 100 ms), the value of the counter is monitored every time the program is executed, and the count value C at that time is checked. Engine speed Ne
Is calculated (step 1811), and if the pulse signals from the rotation sensor 11 are counted for a certain period of time, the count value C is reset to 0 (that is, the counter is reset) (step 1812).

The engine speed Ne is measured as described above. In step 62 of FIG. 6, the standard air amount shown in FIG. 19 is calculated based on the throttle opening TH and the read value of the Ne value. Obtain the standard air amount Qa (S) according to the table. In this standard table, the standard intake air amount with respect to the throttle opening TH and the engine speed Ne is the characteristic data I to
It is set as IV, and in this example, the corresponding standard air amount Qa (S) is obtained according to the above two parameters. This is actually the engine speed
This is because the intake air amount changes with respect to the throttle opening TH when Ne changes. Therefore, it is more accurate if the standard air amount Qa (S) is obtained from the two-dimensional table as shown and the air amount ratio _KQ is calculated. It is possible to make a high correction.

(Effects of the Invention) Thus, as described above, the working hydraulic pressure control device of the present invention basically sets the working hydraulic pressure of the friction element at the time of gear shifting according to the throttle opening, and at the same time, the intake air amount from the intake air amount detecting means. In addition to the correction based on the air amount, in that case, the standard intake air amount data for the throttle opening detected by the throttle opening detecting means is obtained, and the standard intake air amount data and the actual detected by the intake air amount detecting means Since the configuration is such that the operating hydraulic pressure during shifting is corrected using the intake air amount / standard intake air amount, which is the ratio of the intake air amount from the intake air amount detection means to the standard intake air amount data obtained from the intake air amount While the basic control is to determine the hydraulic pressure of the friction element during gear shifting based on the throttle opening, improvements have been made to this, and the ratio between the pre-shift torque and the mid-shift torque has been improved. Can be self-corrected so as to keep constant, and it is possible to cope with a change in engine output due to a factor that causes a change in shift shock. It is possible to prevent changes in gear shift shocks and reduce variations in gear shift quality, and determine the basic hydraulic pressure by the throttle opening to correct the intake air amount / standard intake air amount. By using the ratio, the engine torque change can be appropriately corrected by the change in the intake air amount, and the operating hydraulic pressure of the friction element at the time of the shift can be set while sequentially obtaining it during the shift, so that self-correction is possible. Function can be exerted in the actual situation of the gear shift even during the gear shift, and therefore, at the time of gear shift, the necessary self-correction effect as a gear shift shock change prevention measure is always provided. Rukoto can.

Further, in that case, as described above, not only the improvement of the method of determining the operating oil pressure during gear shifting solely depending on the throttle opening but also the determination of the operating oil pressure is performed.
It is possible to effectively perform the operating hydraulic pressure control at the time of gear shift while avoiding the shock that may occur if the fuel injection amount or the suction negative pressure is used, which may occur at the end of gear shift.

In the second aspect of the present invention, in the hydraulic pressure control of the above configuration, standard intake air amount data with respect to the throttle opening and engine speed is used, and the value of the ratio for shift hydraulic pressure correction is calculated using this. By doing so, it is possible to perform more accurate correction.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a hydraulic pressure control device of the present invention, FIG. 2 is a system diagram showing an embodiment of the present invention device, and FIG. 3 is a flow chart of a control program of a line pressure determination routine executed by a controller in the same example. 4 is a waveform diagram showing an example of a drive signal output for duty control of the line pressure solenoid, and FIG. 5 is a diagram showing an example of a standard line pressure table at the time of gear shift applied by the program of FIG. FIG. 6 is a flow chart showing an example of a program of a subroutine for calculating the intake air amount ratio, FIG. 7 is a flow chart showing an A / D conversion processing program of the throttle opening signal, and FIG. 8 is a standard for the throttle opening. The figure which shows an example of an air volume table, FIG. 9 is a flow chart which shows the A / D conversion processing program of an air volume signal, and FIG. 10 is the linear line of the A / D conversion value. Showing an example of the Qa signal linearization characteristic applied to the compression process, FIG. 11 is a diagram for explaining the relationship between the air amount ratio and the torque ratio, and FIG. 12 is a duty for converting the line pressure value into a duty value. FIG. 13 is a diagram showing an example of a conversion table, FIG. 13 is a torque waveform diagram used to explain the self-correction function with respect to shift point changes, FIG. 14 is a torque waveform diagram used to explain the self-correction function with respect to atmospheric pressure changes, and FIG. 15 is Fig. 16 is a torque waveform diagram for explaining the self-correction function with respect to environmental temperature changes. Fig. 16 is a torque waveform diagram shown as a comparative example for explaining the influence of atmospheric pressure. Fig. 17 is a comparison for explaining the influence of environmental temperature. FIG. 18 is a flowchart showing an example of a program for measuring the engine speed Ne in another embodiment of the device of the present invention, and FIG. 19 is an example of a standard air amount table in the same example. Shows, FIG. 20 is a graph showing changes in torque waveform associated with the shift point change in your shift line pressure based on the throttle opening. 1 ... Engine, 2 ... Automatic transmission 3 ... Control valve 4 ... Line pressure solenoid 5,6 ... Shift solenoid 7 ... Controller, 8 ... Throttle sensor 9 ... Vehicle speed sensor, 10 ... Air flow meter 11 …… Engine rotation sensor 12 …… Oil temperature sensor

Claims (2)

(57) [Claims] 1. A corresponding shift speed is selected by selectively hydraulically operating various friction elements, and a shift to another shift speed is performed by changing a friction element that is hydraulically operated, and the operating hydraulic pressure of the friction element during the shift is controlled. In a possible automatic transmission, the intake air amount detecting means for detecting the intake air amount of the engine, the throttle opening detecting means for detecting the throttle opening, and the throttle opening detecting means for detecting the throttle opening A hydraulic pressure setting means for setting the hydraulic pressure of the friction element at the time of gear shifting, and means for correcting the hydraulic pressure at the time of gear shifting by the setting means based on the intake air amount detected by the intake air amount detecting means. The standard intake air amount data for the throttle opening detected by the throttle opening detecting means is obtained, and the standard intake air amount data and the intake air amount data are obtained. The intake air amount / standard intake air amount, which is the ratio of the intake air amount from the intake air amount detecting device to the standard intake air amount data obtained from the actual intake air amount detected by the amount detecting device, An operating hydraulic pressure control device for an automatic transmission, comprising: operating hydraulic pressure correcting means for correcting operating hydraulic pressure. 2. The standard intake air amount data is standard intake air amount data with respect to the throttle opening and the engine speed, and the ratio is obtained using the standard data. An operating hydraulic pressure control device for an automatic transmission as described in.