JP2715588B2 - Vehicle travel control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle equipped with an automatic transmission, and a shift hydraulic pressure of the automatic transmission is determined according to an accelerator opening of an engine. The present invention relates to a traveling control device for a vehicle.

2. Description of the Related Art For example, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 62-62047 discloses an automatic transmission in which a plurality of hydraulically operated friction elements (clutches, brakes, etc.) incorporated in a gear train are appropriately engaged and disengaged. Are automatically switched so that a plurality of shift speeds can be obtained.

By the way, the above-mentioned friction element is supplied with the shifting hydraulic pressure from the hydraulic pressure control means. However, when the automatic transmission is shifted, if a newly engaged friction element is suddenly engaged, a large shift shock is generated. Therefore, conventionally, the shift hydraulic pressure is controlled according to the engine output.

For example, in the automatic transmission disclosed in the above publication,
The shift hydraulic pressure is adjusted according to the accelerator opening (throttle opening) of the engine.

Problems to be Solved by the Invention However, the output of the engine is determined by the amount of oxygen for burning fuel, that is, the amount of intake air. Since the density is changed, recent engines detect the intake air temperature (outside air temperature) and the outside air pressure, and correct the density of the intake air amount.

For this reason, when the shifting hydraulic pressure is determined only by the accelerator opening that determines the apparent intake air amount as in the automatic transmission, a high altitude where the air pressure is low or a high temperature zone where the air density is low is used. When traveling, the preset shift hydraulic pressure becomes higher with respect to the engine output,
There has been a problem that the shift shock is exacerbated.

In view of the above-mentioned problems, the present invention corrects the shift hydraulic pressure determined by the intake air amount of the automatic transmission based on the intake air temperature and the outside air pressure, thereby producing a friction corresponding to the actual output of the engine. An object of the present invention is to provide a traveling control device for a vehicle in which the fastening timing of elements is precisely controlled.

Means for Solving the Problems In order to achieve this object, the present invention provides a plurality of shift stages by switching a plurality of hydraulically operated friction elements a as shown in FIG. An automatic transmission c for appropriately shifting the speed of rotation and outputting to the drive wheel side, so that the shifting hydraulic pressure of the friction element a is determined by the hydraulic pressure control means d in accordance with the intake air amount of the engine b. In this vehicle, an intake air temperature detecting means e for detecting an intake air temperature and an external air pressure detecting means f for detecting an external air pressure are provided, and the shift hydraulic pressure is determined by the intake air temperature and the external air pressure detected by these detecting means e and f. Is provided by providing a hydraulic pressure correcting means g for correcting

Then, the hydraulic pressure correction means g outputs an external pressure correction coefficient Ha ₁
From the outside air pressure correction data set in advance as a function of the outside air pressure so that the outside air pressure becomes a value within the range of less than 1 to 1 or more across 1, the actual outside air pressure detected by the outside air pressure detecting means is calculated. Means for determining a corresponding outside air pressure correction coefficient Ha ₁ , and an intake air temperature preset as a function of the intake air temperature such that the intake air temperature correction coefficient Ha ₂ is a value within the range of less than 1 to 1 or more. from among the correction data, means for determining the intake air temperature correction coefficient Ha ₂ corresponding to the actual intake air temperature detected by the intake air temperature detecting means, these outside pressure correction coefficient Ha ₁ and intake air temperature correction coefficient H
means for calculating the oxygen concentration correction amount Ha as Ha = Ha ₁ × Ha ₂ by multiplying the a _2, the oxygen density correction amount Ha to shift pressure P _L which is set in advance according to the intake air amount of the engine It includes means for calculating the corrected hydraulic pressure P by multiplication as P = P _L × Ha, and means for giving the corrected hydraulic pressure P to a hydraulic pressure control valve as a control command thereof.

With the above configuration, in the vehicle traveling control device of the present invention, the shift hydraulic pressure of the automatic transmission c determined according to the intake air amount is adjusted by the hydraulic pressure correction means g according to the intake air temperature and the outside air pressure. Thus, the shift hydraulic pressure can be precisely controlled in accordance with the output actually generated by the engine b, and the frictional element a determined by the relationship between the engine output and the shift hydraulic pressure can be controlled. Is always kept constant, and even when the outside air temperature and the outside air pressure are changed, the occurrence of the engagement shock can be significantly suppressed.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

That is, FIG. 2 shows an embodiment of a traveling control device for a vehicle according to the present invention, in which 10 is an engine, 12 is an automatic transmission, and the output rotation of the engine 10 is transmitted through a torque converter 14 to the automatic transmission 12. The input engine speed is appropriately shifted by the automatic transmission 12 and transmitted to driving wheels (not shown).

The automatic transmission 12 is constructed is a gear train by providing a first planetary gear set PG ₁ and the second planetary gear set PG _2, as shown in Figure 3.

The first and second planetary gear sets PG ₁ and PG ₂ are each configured as a simple planetary gear, and include first and second sun gears S ₁ and S ₂ and _first and second sun gears S ₁ and S ₂ .
Second pinion gears P ₁ , P ₂ and first and second ring gears R ₁ , R
₂ and first and second pinion carriers PC ₁ and PC ₂ .

As shown in the figure, the gear train composed of the first and second planetary gear sets PG ₁ and PG ₂ has an input shaft
I / S and the reverse clutch R for connecting the first sun gear S ₁ /
C, input shaft I / S and first pinion carrier PC ₁
High clutch H / C connecting to the first pinion carrier P
Forward clutch connecting C ₁ and second ring gear R ₂
F / C, band brake B / B to the first sun gear S ₁ is fixed to the casing C / S side, a first pinion carrier PC ₁ a casing
A low and reverse brake L & R / B fixed to the C / S side is provided.

Further, the forward clutch F / C and the second ring gear R
₂ , a forward one-way clutch F / OC is provided, and a first pinion carrier PC ₁ and a casing C
/ S is provided between the first pinion carrier PC ₁ and the second ring gear R.
₂ , an overrun clutch O / R / C is arranged in parallel with the forward one-way clutch F / O / C.

3, the rotation of the engine 10 is input to the input shaft I / S via the torque converter 14.

Incidentally, in the main transmission 12, as shown in Table 1 below, each friction element (R / C, H / C, F / C, B / B, L & R / B) is supplied from the hydraulic pressure control valve 16. The various shift speeds can be obtained by engaging and disengaging with the changed shift hydraulic pressure.

The hydraulic pressure control valve 16 is driven by a shift signal output from the A / T control unit 18 based on, for example, a shift schedule shown in FIG.

The A / T control unit 18 receives a throttle opening signal detected by the throttle opening sensor 200 and a vehicle speed signal detected by the vehicle speed sensor 202, and based on these signals, sets the current setting from the shift schedule. The gear to be shifted is determined as shown in Table 1.

In the table, a circle indicates a fastened state, and a blank indicates a released state.

In addition, the forward one-way clutch F / O ・ C
The second ring gear R to the first pinion carrier PC _1
2 is free when rotating in the forward direction, locked when rotating in the reverse direction, and the low one-way clutch L / O
C is unlocked, upon rotation in the reverse direction during rotation of the first forward direction of the pinion carrier PC _1.

Further, although the above-mentioned overrun clutch O / R / C is not shown in Table 1, the overrun clutch O / R / C has an accelerator opening of 1/16 or less at the lower gear side of the third speed or lower. By being concluded, the forward one-way clutch F /
The engine brake is actuated without the OC function.

FIG. 5 shows the details of the hydraulic pressure control valve 16 and comprises the following valves.

That is, the hydraulic pressure control valve 16 includes a pressure regulator valve 20, a pressure modifier valve 22,
Line pressure solenoid 24, pilot valve 26, torque converter regulator valve 28, lock-up control valve 30, shuttle valve 32, lock-up solenoid 34, manual valve 3
6, first shift valve 38, second shift valve 40, first shift solenoid 42, second shift solenoid 44, forward clutch control valve 46, 3-2 timing valve 48, 4-2 relay valve 50, 4
-2 sequence valve 52, I range pressure reducing valve 54, shuttle valve 56, overrun clutch control valve 58, third shift solenoid 60, overrun clutch pressure reducing valve 62, 2nd speed servo apply pressure accumulator 64, 3rd speed servo release pressure accumulator A 66, 4-speed servo apply pressure accumulator 68 and an accumulator control valve 70 are provided.

The respective components of the hydraulic pressure control valve 16 have the relationship shown in the drawing, and the reverse clutch R / C, high clutch H / C, forward clutch F / C, brake band
B / B, low and reverse brakes L & R / B, overrun clutches O / R / C are connected to the frictional elements and oil pump O / P, and the first shift valve 38 and the second shift valve 40 are switched. Supply and stop of the hydraulic pressure to the name friction element are performed.

The detailed configuration and function of the components constituting the hydraulic pressure control valve 16 are the same as those described in Japanese Patent Application Laid-Open No. 62-62047, and a detailed description thereof will be omitted.

Incidentally, the band brake B / B is operated by a band servo B / S, and the band servo B / S is a 2nd speed servo apply pressure chamber 2S / A, a 3rd speed servo release pressure chamber 3S / R, and a 4th speed servo apply. Composed of 4S / A pressure chamber, 2-speed servo apply pressure chamber
Band brake B / B by supplying hydraulic pressure to 2S / A
The band brake B / B is released by supplying the hydraulic pressure to the third-speed servo release pressure chamber 3S / R in this state, and further, the liquid is supplied to the fourth-speed servo apply pressure chamber 4S / A in this state. When the pressure is supplied, the band brakes B / B are fastened.

The switching of the first and second shift valves 38 and 40 is performed by turning on and off the first and second shift solenoids 42 and 44. When the first and second shift solenoids 42 and 44 are turned on, the pilot valves are connected to the first and second shift valves 38 and 40. The pressure is supplied to the right half position (upper position) in the figure, and when OFF, the pilot pressure is drained to
The second shift valves 38 and 40 are in the left half position (lower position) in the figure, and are switched on and off as shown in the following Table 2 so that each shift speed can be obtained. .

The switching signals for the first and second shift valves 38 and 40 are output from the A / T control unit 18 shown in FIG. 2. Are determined based on the throttle opening signal obtained from the throttle sensor 200 and the vehicle speed signal obtained from the vehicle speed sensor 202 based on the shift schedule shown in FIG.

In the hydraulic pressure control valve 16, the discharge pressure of the oil pump O / P driven by the engine is adjusted as line pressure by the pressure regulator valve 20,
The line pressure is supplied to each of the friction elements as a shifting hydraulic pressure.

As shown in FIG. 4, the pressure regulator valve 20 acts as a force that causes the discharge pressure of the oil pump O / P acting on the pressure receiving surface 20d to act downward in the figure.
biasing force and circuit of spring 20a contracted between c and
The modifier pressure acting on the lower end of the plug 20c via 76 acts as a force acting upward in the drawing, and the spool 20b is moved to a position where these forces are balanced, and the port 2
The line pressure is adjusted to 0e.

The modifier pressure is created by a pressure modifier valve 22, which is controlled by a signal pressure supplied from a line pressure solenoid 24.

The line pressure solenoid 24 is an on-drain type solenoid valve. The duty of the line pressure solenoid 24 is controlled to control the pilot pressure output from the pilot valve 26. The pressure is supplied to the pressure modifier valve 22.

Therefore, by controlling the signal pressure by the line pressure solenoid 24, the modifier pressure can be changed, and thus the line pressure can be controlled by the pressure regulator valve 20.

Incidentally, the line pressure solenoid 24 is driven by a control signal output from a hydraulic pressure control means 204 incorporated in the A / T control unit 16 shown in FIG. 2, and usually a throttle valve as shown in FIG. It is controlled as a signal pressure corresponding to the opening.

Here, in the present embodiment, a thermo sensor 210 as an intake air temperature detecting means is provided in the intake passage 10a of the engine 10, and a gauge pressure sensor 212 is provided as an outside air pressure detecting means, and the thermo sensor 210 and the gauge pressure sensor 212 are provided. The intake air temperature signal and the outside air pressure signal detected in step (1) are introduced into the A / T control unit 18.

And the above-mentioned intake air temperature signal and outside air pressure signal are A / T
Hydraulic pressure correcting means 214 provided in control unit 18
The hydraulic pressure correction means 214 corrects the hydraulic pressure control signal output from the hydraulic pressure control means 204 based on the intake air temperature signal and the outside air pressure signal.

The thermo sensor 210 and the gauge pressure sensor 212
The one commonly used for correcting the intake air amount of the engine 10 can be shared.

With the above configuration, the function of the vehicle travel control device of the present embodiment will be described below with reference to the flowchart shown in FIG.

That is, the flowchart of FIG. 7 shows an example of processing executed by the A / T control unit 18 for controlling the line pressure.
It is assumed that processing is performed every predetermined short time (for example, 10 msec) by being turned ON.

That is, the first step I in the above flowchart, reads the throttle opening degree signal corresponding to the intake air amount, the read atmospheric pressure signal P _A detected by the gauge pressure sensor 212 in the next step II, thermo step III The intake air temperature signal T _A detected by the sensor 210 is read.

Then, based on the throttle opening signal read in the next step IV in the step I, to determine the transmission fluid pressure P _L from the sixth FIG.

Also, atmospheric pressure signal read in the next step V step II and step III P _A and the intake air temperature signal T
Based on _A , the correction amount Ha of the oxygen density taken into the engine 10 is determined from the correction data shown in FIGS.

That is, FIG. 8 shows a correction coefficient Ha ₁ for the atmospheric pressure signal P _A , FIG. 9 shows a correction coefficient Ha ₂ for the intake air temperature signal T _A , and the above oxygen density correction amount Ha is Ha = Ha ₁ × Ha ₂ can be obtained.

Then, in the next step VI, the correction hydraulic pressure P required at the time of actually engaging the friction element is calculated from the oxygen density correction amount Ha,
Obtained as P = P _L × Ha.

Incidentally, P _L is a shift pressure which is determined in the step IV.

Then, in the next step VII, the control amount (duty ratio) output to the line pressure solenoid 24 of the hydraulic pressure control valve 16 is determined from the map shown in FIG.

Therefore, in the travel control device of the present embodiment, the line pressure regulated by the pressure regulator valve 20 is a signal output to the line pressure solenoid 24,
Since some of the pressures are corrected in accordance with the intake air temperature and the external air pressure via 214, the transmission hydraulic pressure can be adjusted to the engine output in which the intake air amount is corrected by the intake air temperature and the external air pressure.

For this reason, even when the vehicle is traveling in a highland where the air pressure is low or a tropical region where the air density is low, the relationship between the engine output and the shifting hydraulic pressure can always be kept constant. Optimize timing,
Shift shock and shift feeling can be prevented from being deteriorated.

The traveling control device for a vehicle according to the present invention can be applied to an engine provided with a supercharger for determining a supercharging pressure of a turbocharger or the like based on a pressure difference from an atmospheric pressure.

In the above-described embodiment, the intake air amount for determining the shift hydraulic pressure is estimated based on the throttle opening. However, the present invention is not limited to this, and the intake air amount is estimated based on the throttle opening and the engine speed. Alternatively, the amount of intake air can be directly set by an air flow meter (a hot wire type, a Kalman type, a flap type, etc.).

Effect of the Invention As described above, in the vehicle traveling control device of the present invention, the shift hydraulic pressure of the automatic transmission determined according to the intake air amount of the engine is controlled by the intake air temperature via the hydraulic pressure correction means. And the pressure is corrected by the outside pressure, so that the shift hydraulic pressure can be precisely controlled in accordance with the output actually generated by the engine, and is determined by the relationship between the engine output and the shift hydraulic pressure. It is possible to always keep the fastening timing of the friction element constant.

Therefore, even when the outside air temperature and outside air pressure fluctuate,
An excellent result is obtained in which the shift hydraulic pressure is maintained in an optimum state to prevent the engagement shock and the shift feeling from being deteriorated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the concept of the present invention, FIG. 2 is a schematic diagram showing one embodiment of the present invention, FIG. 3 is a schematic diagram showing an automatic transmission gear train used in the present invention, FIG. Is an explanatory diagram showing a shift schedule of the automatic transmission used in the present invention, FIG. 5 is a schematic configuration diagram showing one embodiment of a hydraulic pressure control valve of the automatic transmission used in the present invention, and FIG. FIG. 7 is a characteristic diagram of the shift hydraulic pressure determined by the degree, FIG. 7 is a flowchart showing one processing example for executing the control of the present invention, and FIG. 8 is a correction of the shift hydraulic pressure determined by the outside air pressure in the present invention. Data showing coefficients, FIG. 9 shows data showing a correction coefficient of the shift hydraulic pressure determined by the intake air temperature in the present invention, and FIG. 10 shows a duty ratio outputted to obtain a corrected shift hydraulic pressure in the present invention. It is a map of. 10 ... Engine, 12 ... Automatic transmission, 16 ... Hydraulic control valve, 18 ... A / T control unit, 200 ...
... Throttle opening sensor, 204 ... Hydraulic pressure control means, 210 ...
... thermo sensor (intake air temperature detecting means), 212 ... gauge pressure sensor (outside atmospheric pressure detecting means), 214 ... hydraulic pressure correcting means, R / C
… Reverse clutch (friction element), H / C… High clutch (friction element), F / C… Forward clutch (friction element), B / B… Band brake (friction element), L & R / B
…… Low and reverse brakes (frictional elements).

Claims (1)

(57) [Claims] 1. An automatic transmission, wherein a plurality of shift speeds are obtained by switching a plurality of hydraulically operated friction elements, and an automatic transmission for appropriately shifting the output rotation of an engine to output to a drive wheel side. In a vehicle in which the shift hydraulic pressure is determined according to the intake air amount of the engine by the hydraulic pressure control means, an intake air temperature detection means for detecting an intake air temperature and an external air pressure detection means for detecting an external air pressure, Hydraulic pressure correcting means for correcting the shift hydraulic pressure based on the intake air temperature and the external pressure detected by each of these detecting means, wherein the hydraulic pressure correcting means has an external pressure correction coefficient Ha ₁ of 1 The external pressure correction coefficient Ha corresponding to the actual external pressure detected by the external pressure detection means from among the external pressure correction data set in advance as a function of the external pressure so as to be a value within the range of less than or equal to 1 or more. means for determining _one intake From among preset intake air temperature correction data as a function of intake air temperature Metropolitan to a value within one or more ranges from why less than one correction factor Ha ₂ is 1, the actual detected by the intake air temperature detecting means means for determining the intake air temperature correction coefficient Ha ₂ corresponding to the intake air temperature, to calculate the oxygen concentration correction amount Ha by multiplying these outside pressure correction coefficient Ha ₁ and intake air temperature correction coefficient Ha ₂ as Ha = Ha ₁ × Ha ₂ Means and a variable hydraulic pressure preset according to the intake air amount of the engine
P _L is multiplied by the oxygen density correction amount Ha to obtain a corrected hydraulic pressure P P _L × Ha
And a means for giving the corrected hydraulic pressure P to a hydraulic pressure control valve as a control command therefor.