JP2688833B2 - Control device for vehicle with automatic transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a vehicle with an automatic transmission that performs gear shifting and lockup control with reference to learning data of a throttle fully closed point.

(Prior Art) Conventionally, in a vehicle with an automatic transmission, a so-called AT vehicle,
After assembling the integral interlocking structure of the idle switch and the throttle sensor to the throttle body, correcting this assembly error, the throttle full closing point voltage is, for example, 1.5 volts, and the lockup OFF voltage is, for example, 2.0 volts. It was manually adjusted so that the kickdown voltage was 3.5 V and the throttle full-open voltage was 4.0 V, for example.

However, since such an adjustment operation requires a great number of man-hours, recently, there has been adopted a means for omitting the adjustment and correcting the voltage value variation due to the above-mentioned assembly error by the learning control of the CPU. .

That is, as described in JP-A-62-151662, the idle switch and the throttle sensor are provided, and the voltage when the throttle fully closed point is learned based on the above-mentioned switching of the idle switch from ON to OFF is set. As a reference voltage,
There is a control device for an AT vehicle that compares the reference voltage with the current throttle voltage detected based on the output of the throttle sensor to predict the throttle opening and control the shift.

However, in this conventional device, immediately after the battery is replaced, the above-mentioned CPU does not have a memory of the throttle full closing point voltage, and the throttle full closing point voltage of the throttle sensor is in an unknown state. The initial value was initially set to a value as shown in FIG. 5a, and gear shifting and lockup were controlled.

For this reason, a deviation occurs between the initial value shown in FIG. 5a and the fully closed point and fully opened point voltage of the throttle sensor, causing the following problems.

That is, when the throttle sensor has a voltage characteristic as a variation lower limit product as shown in FIG. Since it is 3.5V, there was a problem that it did not kick down even if the accelerator was depressed.

On the other hand, when the throttle sensor has the voltage characteristics as the variation upper limit product as shown in FIG. 5C, the throttle full closing point voltage when the accelerator is fully closed is 2.5 V, whereas the initial value is locked. Up OFF voltage is 2.0
Since it is a bolt, even if you release your foot from the accelerator, the lockup is not released, and there is a problem that engine stop and engine brake shock occur during sudden deceleration and sudden braking.

(Object of the Invention) The present invention can prevent an engine stop at the time of sudden deceleration by forcibly prohibiting lockup until the throttle fully closed point is learned immediately after battery replacement. An object of the present invention is to provide a control device for a vehicle with an automatic transmission.

(Structure of the Invention) The present invention has an idle switch and a throttle sensor, and uses a voltage when a throttle full closing point is learned based on switching of the idle switch from ON to OFF as a reference voltage, In a vehicle with an automatic transmission equipped with shift control means for predicting the throttle opening and controlling the shift by comparing the voltage with the current throttle voltage detected based on the output of the throttle sensor, The control device for a vehicle with an automatic transmission is provided with a discriminating means for discriminating the presence / absence of learning and a lock-up prohibiting means based on the throttle fully closed point unlearned output from the discriminating means.

(Effect of the Invention) According to the present invention, based on the determination result of the determination means, the lock-up prohibition means causes the lock-up clutch and the front to be operated at the time of unlearning output in which the throttle fully closed point is not learned immediately after battery replacement. Since the lockup due to the engagement with the cover is forcibly prohibited, it is possible to reliably prevent the engine stop during sudden deceleration.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

The drawing shows a control device for a vehicle with an automatic transmission. In FIG. 1, a torque converter 1 is fixedly installed on one side of a front cover 3 and a case 4 connected to an engine output shaft 2, and an engine output is fixed. A pump 5 that rotates integrally with the shaft 2 is rotatably provided on the other side of the front cover 3 and the case 4 described above so as to face the pump 5, and is rotated by hydraulic oil by the rotation of the pump 5. The driven turbine 6, the stator 7 interposed between the pump 5 and the turbine 6 described above, which increases the torque when the speed ratio of the turbine speed to the pump speed is equal to or lower than a predetermined value, and the stator 7 described above. It has a lockup clutch 8 interposed between the turbine 6 and the front cover 3.

Then, the rotation of the turbine 6 is output by the turbine shaft 9 and input to a multi-stage transmission gear device (not shown), and the lock-up clutch 8 is connected to the turbine shaft 9 and fastened to the front cover 3. When the above is done, the engine output shaft 2 and the turbine shaft 9 are directly connected via the front cover 3 and the lock-up clutch 8.

Further, the torque converter 1 includes a hydraulic control circuit 10
Turbine side chamber (R chamber) via the converter line 11
The hydraulic oil is introduced into 12, and the lockup clutch 8 is always biased in the engaging direction by the pressure of the hydraulic oil, and the lockup clutch 8 and the front cover 3 are
Lock-up release line 14 in the space (F room) 13 between
Is connected, and the lockup clutch 8 is released when hydraulic pressure (release pressure) is introduced from the lockup release line 14 into the space (F chamber) 13.

Further, the torque converter 1 is connected to a converter outline 15 that sends out hydraulic oil to an oil cooler via a pressure maintaining valve.

Furthermore, the hydraulic control circuit 10 described above automatically controls the shift of a multi-stage transmission gear device (not shown) of the automatic transmission 16 according to the accelerator opening and the position of the selector lever.

FIG. 2 shows a control circuit of a control device for a vehicle with an automatic transmission, in which a throttle body 17 has an idle switch 18 and a throttle sensor 19 built therein.

The idle switch 18 and throttle sensor 19 described above
Is an integrated interlocking structure, the movable contact 20 is a common terminal 18a of the idle switch 18, an idle contact 18b, a potentiometer 19
a, sliding on the full load contact 19b.

Here, the common terminal 18a of the idle switch 18 described above.
Is connected to the control power supply terminal 22 via the resistor 21 and is connected to the input port of the CPU 30 via the inverter 23.

The idle contact 18b of the idle switch 18 is connected to the ground.

Further, the full load contact 19b of the throttle sensor 19 is connected to the vibration damping power supply terminal 24.

Furthermore, the movable contact 20 is connected to the CPU 30 described above via a comparator 25 and an AD converter 26.

The CPU 30 described above is based on each input of the idle switch signal of the output stage of the inverter 23, the throttle signal of the output stage of the AD converter 26, the turbine speed signal (TSP), and the vehicle speed signal (VSP), according to the program stored in the ROM 27, The hydraulic control circuit 10 is driven and controlled, and the RAM 28 stores necessary data such as initial set data, lock-up prohibition flag, and throttle fully closed point data.

A battery 31 is connected to the RAM 28 via a backup power supply 29, while a battery is connected to the CPU 30 and ROM 27 via a system power supply 32 and an ignition switch 33.
31 is connected.

Here, the above-mentioned CPU 30 uses the voltage at the time of learning the throttle fully closed point based on the switching of the idle switch 18 from ON to OFF as the reference voltage, and detects it based on this reference voltage and the output of the throttle sensor 19. The shift control means for predicting the throttle opening and controlling the shift by comparing the current throttle voltage with the current throttle voltage (see the seventh step described later).
And a determination means for determining whether or not the throttle fully closed point is learned (see the second step described later), and a prohibition means for inhibiting lockup based on the throttle fully closed point unlearned output from this determination means (described later). (See the third and fourth steps).

The operation of the control device for a vehicle with an automatic transmission configured as described above will be described with reference to the flowchart of FIG.

When the ignition switch 33 is turned on (ON) in the first step 41, the CPU 30 causes the RAM 28 to be operated in the next second step 42.
It is determined whether or not the throttle full closing point data is stored in the predetermined area of.

Before the throttle fully closed point learning immediately after the replacement of the battery 31, the throttle fully closed point data is not stored in the predetermined area of the RAM 28 described above, so the routine proceeds to the next third step 43.

In the third step 43, the CPU 30 sets the lockup prohibition flag "1" in a predetermined area of the RAM 28. That is, lock-up prohibition is set.

Next, in a fourth step 44, the CPU 30 initially sets the throttle totally closed point data.

That is, since the throttle fully closed point data is not stored at this time, the throttle sensor having the voltage characteristic as the variation lower limit product as shown in FIG.
Alternatively, 1 volt is added to both the throttle sensor 19 having the voltage characteristic as the upper limit variation and the throttle sensor 19 having the voltage characteristic between the lower limit and the upper limit as shown in FIG. 4c. The initial value should be set to a proper value to ensure kickdown for any throttle sensor 19.

Next, in a fifth step 45, the CPU 30 reads the throttle signal, turbine speed signal (TSP), vehicle speed signal (VSP) and idle switch signal.

Next, in a sixth step 46, the CPU 30 determines the presence / absence of an idle switch signal, and when the aisle switch 18 remains ON and the throttle full closing point has not been learned, the process proceeds to the next seventh step 47.

In this seventh step 47, the CPU 30 makes a shift determination,
The shift output process is executed based on this determination result.

Next, in an eighth step 48, the CPU 30 determines whether the lockup prohibition flag stored in advance in a predetermined area of the RAM 28 is "1" or "0", and in this case, the lockup prohibition flag is determined in the third step 43 described above. Is "1", the process returns to the above-mentioned fifth step 45.

That is, when the throttle fully closed point is not learned immediately after the battery is replaced, in the above-described third step 43.
By setting a lock-up prohibition flag in a predetermined area of the RAM 28, the lock-up due to the engagement of the lock-up clutch 8 and the front cover 3 is forcibly prohibited, and the engine stop during sudden deceleration is surely prevented.

In addition, when the throttle closing point is not learned, the variation of the throttle sensor 19 is set by setting the initial value of adding 1 volt to the input voltage from all the throttle sensors in the above-mentioned fourth step 44. Regardless of, secure a kickdown.

On the other hand, in the above-mentioned sixth step 46, the idle switch 18
When the CPU 30 determines that has been switched from ON to OFF, the process proceeds to the next ninth step 49.

In the ninth step 49, the CPU 30 sets the lockup prohibition flag of the predetermined area of the RAM 28 to "0".

Next, in the tenth step 50, the CPU 30 executes the above-mentioned fifth step 4
Corresponding to the reading result of 5, the throttle fully closed point data in RAM 28 is updated to the throttle voltage corresponding to the actual product.

For example, in the case of the throttle sensor having the voltage characteristic of the variation lower limit product shown in FIG. 4b, the throttle full closing point data is updated to 0.5 volt, and the throttle having the voltage characteristic of the variation upper limit product shown in FIG. 4C. In the case of a sensor, update the throttle closing point data to 2.5 volts.

In the case of Fig. 4b, the lock-up OFF voltage is 1.
Set the kickdown voltage to 0V and the kickdown voltage to 2.5V. In the case of Fig. 4c, the lockup OFF voltage is set to 3V and the kickdown voltage is set to 4.5V, based on the throttle full closing point data of 2.5V. Of course, it is set to.

After the throttle fully closed point learning in the tenth step 50 described above, the lock-up prohibition flag in the RAM 28 is "0", so after the determination in the eighth step 48, the next eleventh step is performed. Move to 51.

In this eleventh step 51, the CPU 30 makes a lockup determination, and executes a lockup output process based on the determination result.

In addition, after the throttle fully closed point learning in the tenth step 50 described above, since the throttle fully closed point data corresponding to the throttle sensor is written in a predetermined area of the RAM 28, the second step 42 described above is performed. After the determination, the routine proceeds to the next twelfth step 52, and the shift control and lockup control after the normal learning are executed based on the flowchart of FIG. 3 below.

In short, lock-up is forcibly prohibited until the throttle full-close point is learned immediately after battery replacement, so even if there is a variation in the full-close point voltage due to a throttle sensor assembly error or the like. There is an effect that the engine stop at the time of sudden deceleration can be surely prevented.

As shown in the embodiment, if the initial value is set to add 1 volt to the throttle input voltage until the throttle fully closed point is learned, the kickdown of any throttle sensor 19 is suppressed. It is possible to secure it.

In the correspondence between the configuration of the present invention and the above-described embodiment, the shift control means of the present invention corresponds to the seventh step 47 by the CPU 30 of the embodiment, and similarly, the determination means is the second step 42 by the CPU 30. The lock-up prohibition means corresponds to the third and fourth steps 43 and 44 by the CPU 30, but the present invention is not limited to the configuration of the above-described embodiment.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a sectional view of a torque converter in a vehicle with an automatic transmission, FIG. 2 is a control circuit diagram showing a control device for a vehicle with an automatic transmission, and FIG. 3 is a flowchart. 4a is an explanatory view showing the design target value of the throttle sensor voltage characteristic, FIG. 4b is an explanatory view showing the throttle sensor voltage characteristic of the variation lower limit product, and FIG. 4c is a throttle sensor voltage characteristic of the variation upper limit product. 5a is an explanatory view of a conventional initial set value, FIG. 5b is an explanatory view showing a throttle sensor voltage characteristic of a variation lower limit product, and FIG. 5c is a throttle sensor voltage characteristic of a variation upper limit product. FIG. 18 …… Idle switch 19 …… Throttle sensor 30 …… CPU, 42 …… 2nd step 43 …… 3rd step, 44 …… 4th step 47 …… 7th step

Claims (1)

(57) [Claims] 1. A throttle switch having an idle switch and a throttle sensor, wherein a reference voltage is a voltage when a throttle full closing point is learned based on switching of the idle switch from ON to OFF. In a vehicle with an automatic transmission equipped with shift control means that predicts the throttle opening and controls the gear shift by comparing it with the current throttle voltage detected based on the sensor output. A control device for a vehicle with an automatic transmission, comprising: a discriminating means for discriminating whether or not a lock-up prohibiting means is provided based on a throttle fully closed point unlearned output from the discriminating means.