JPH0544826A - Controller of automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To enable specified control to be carried out even if kind of fuel and characteristic of engine output torque are varied by correcting a parameter which represents detected engine load based on concentration detected by a standard fuel concentration detection means so as to control an automatic transmission. CONSTITUTION:A cylinder intake air quantity calculated based on an intake air flow quantity Q detected by an air flow meter 8 and engine speed N detected by a crank angle sensor 9 is set as a parameter TQ which represents engine load by means of a control unit 6. On the other hand, a correction coefficient COMET is set based on alcohol concentration detected by an alcohol concentration sensor 12 and the parameter TQ is multiplied by the correction coefficient COMET and the corrected result is finally set as a parameter TQSEN which represents the engine load. Line pressure in a control valve group 5 is set based on the parameter TQSEN.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle automatic transmission control device, and more particularly to control of an automatic transmission based on engine load parameters.

[0002]

2. Description of the Related Art In a shift control device for a vehicle automatic transmission,
Conventionally, a shift pattern (shift map) set in advance corresponding to a throttle valve opening and a vehicle speed, which are parameters representing engine load, is provided in advance, and the shift pattern is based on the detected values of the vehicle speed and the throttle valve opening. The gear position is determined with reference to the above, and the gear shift operation is performed in the transmission so as to match the determined gear position (Japanese Patent Laid-Open No. 6-58242).
(See, for example, JP-A 1-257332).

There is also a system in which the line pressure of oil supplied to a hydraulic circuit for controlling each shift element of an automatic transmission is adjusted in accordance with a throttle valve opening which is a parameter representative of an engine load. .. As the parameter representing the engine load, parameters related to the engine intake air amount such as boost and intake air amount are generally used in addition to the throttle valve opening.

[0004]

By the way, in recent years, the development of an internal combustion engine in which alcohol such as methanol is used as an alternative fuel to gasoline has been advanced (see Japanese Patent Laid-Open No. 56-98540, etc.). This is one that can be used by switching between gasoline and alcohol, or by mixing them, and is equipped with an alcohol concentration sensor that detects the alcohol concentration in the fuel. The fuel supply amount to the engine is corrected based on the alcohol concentration.

When an internal combustion engine and an automatic transmission that can be used by switching gasoline or alcohol or by mixing them are combined as described above, the engine intake is used as a parameter representing the engine load as described above. When the gear shift control or the line pressure control is performed using the parameter related to the air amount, the following problems occur.

Originally, a parameter representative of the engine load is detected for the purpose of performing shift control and line pressure adjustment according to the engine output torque, but when the alcohol concentration changes, the same throttle valve opening, boost, intake Since the engine output torque changes as shown in FIG. 4 even with the amount of air, the control based on the parameters as described above cannot accurately control the engine output torque.

For example, if throttle valve opening, boost, intake air amount, etc. are used as parameters representing engine load and the line pressure is controlled based on these parameters, shift shock may occur depending on changes in alcohol concentration. However, there is a risk that frictional elements may slip, and in gear change control, gear change will not be performed under appropriate conditions depending on the change in alcohol concentration, which will deteriorate drivability and fuel consumption due to the use of alcohol fuel. The improvement effect may not be sufficiently obtained.

The present invention has been made in view of the above problems, and in an engine capable of using different fuels such as alcohol and gasoline, the fuel supplied to the engine changes and the characteristic of the engine output torque is changed. It is an object of the present invention to provide a control device for an automatic transmission for a vehicle, which can perform desired control based on a parameter related to an intake air amount such as a throttle valve opening even if it changes.

[0009]

Therefore, a control device for an automatic transmission for a vehicle according to the present invention is for a vehicle in which an engine combined with the automatic transmission is an engine which can switch or mix different types of fuel. A control device for an automatic transmission, which is configured as shown in FIG. In FIG. 1, the reference fuel concentration detecting means detects the concentration of the reference fuel in the fuel supplied to the engine.

Further, the engine load parameter detecting means detects a parameter representative of the engine load and related to the intake air amount of the engine. Then, the engine load parameter correction means corrects the parameter representing the engine load detected by the engine load parameter detection means based on the concentration detected by the reference fuel concentration detection means.

Here, the control means controls the automatic transmission based on the engine load parameters corrected by the engine load parameter correction means.

[0012]

That is, the engine combined with the automatic transmission to which the present invention is applied is an engine that can be used by switching or mixing different types of fuel, and the same cylinder intake air amount can be obtained depending on the reference fuel concentration in the supplied fuel. When the engine output torque obtained for the engine changes, the detected engine load parameter is a parameter related to the intake air amount, and therefore the engine load parameter does not accurately represent the engine output torque.

Therefore, by correcting the detected engine load parameter based on the reference fuel concentration, the corrected engine load parameter becomes a value that corresponds to the true engine output torque according to the change in the reference fuel concentration. I did it.

[0014]

EXAMPLES Examples of the present invention will be described below. In FIG. 2 showing the system configuration of this embodiment, an automatic transmission 2 is connected to the output side of an engine 1 mounted on a vehicle (not shown). The automatic transmission 2 is connected to the torque converter 3 interposed on the output side of the engine 1 via the torque converter 3 so that the engine output torque is equal to the torque converter 3.
Control for controlling the hydraulic pressure as well as controlling the gear type transmission 4 (transmission mechanism) transmitted via the gears and various actuators for connecting / disconnecting various transmission elements in the gear type transmission 4. And a valve group 5.

Signals from various sensors are input to the control unit 6. As the various sensors, the engine 1 is provided on the upstream side of the throttle valve 7 of the intake system of the engine 1.
A hot-wire type air flow meter 8 for detecting the intake air flow rate Q is provided. A crank angle sensor 9 is provided on the crank shaft of the engine 1 or a shaft (for example, a cam shaft) that rotates in synchronization with the crank shaft. The signal from the crank angle sensor 9 is, for example, a reference pulse signal for each reference crank angle, and the engine speed N is determined by the cycle of the reference pulse signal.
Is calculated.

A vehicle speed sensor 11 for detecting a vehicle speed VSP by obtaining a rotation signal from the output shaft 10 of the automatic transmission 2 is provided. Further, the engine 1 in the present embodiment is an engine capable of using a mixed fuel of alcohol and gasoline, which are different fuels, and an alcohol concentration sensor 12 for detecting an alcohol concentration as a reference fuel in the mixed fuel is used. It is provided. The alcohol concentration sensor 12 as the reference fuel concentration detection means is a known sensor that detects the concentration by utilizing the fact that the capacitance of the fuel changes due to the change in alcohol concentration, and the alcohol detected by this sensor 12 The fuel supply amount of the engine 1 is electronically controlled based on the concentration, and the alcohol concentration is used as control information of the automatic transmission as described later.

The control unit 6 is, for example,
Engine control (for fuel injection control and ignition timing control) CPU,
An integrated type with a built-in CPU for automatic transmission control,
A dual port RAM accessible from both CPUs is used, and by adopting such a configuration, data calculated by both CPUs can be shared. The automatic transmission control CPU of the control unit 6 refers to an operation position signal of the select lever operated by the driver, and when the select lever is in the drive range (D range), refers to a preset shift map to set the first speed. The automatic shift control is performed to automatically set the shift position of the 4th speed and control the gear type transmission 4 to the shift position via the control valve group 5. Further, the automatic transmission control CPU adjusts the oil discharged from an oil pump (not shown) to an appropriate line pressure according to the engine output torque (input torque of the transmission) and supplies it to the hydraulic circuit that controls each transmission element. To do.

Here, the above line pressure control performed by the automatic transmission control CPU of the control unit 6 will be described with reference to the flowchart of FIG. In the present embodiment, the functions as the engine load parameter correction means and the control means are provided by software in the control unit 6 as shown in the flowchart of FIG.

Further, in this embodiment, as will be described later, the cylinder intake air amount obtained from the intake air flow rate Q detected by the air flow meter 8 and the engine speed N detected by the crank angle sensor 9 is Since the engine load is used as a representative parameter, the engine load parameter detection means corresponds to the air flow meter 8 and the crank angle sensor 9.

In the flow chart of FIG. 3, first, in step 1 (denoted as S1 in the figure, the same applies hereinafter),
The intake air flow rate QF corresponding to the friction loss of the engine is obtained by referring to a map stored in advance corresponding to the engine speed N. In the next step 2, the intake air flow rate Q detected by the air flow meter 8 is subtracted from the friction loss amount QF obtained in the step 1 and set to Qf.

In step 3, the intake air flow rate Qf subtracted and corrected by the friction loss amount QF is divided by the engine speed N to obtain the intake air amount per unit engine speed, which is a parameter representative of the engine load. As TQ1. Then, in step 4, the alcohol concentration sensor 12
Based on the alcohol concentration in the supplied fuel detected in
A correction coefficient COMET for correcting the engine load parameter TQ1 is set.

In this embodiment, the fuel supplied is 100% gasoline.
Is standard, and the correction coefficient COMET is
As shown in FIG. 3, when the alcohol concentration is 0%, in other words, when the gasoline is 100%, it is set to 1.0, which is substantially uncorrected, and becomes larger than 1.0 as the alcohol concentration increases. It is set so that the engine load parameter TQ1 is increased and corrected. This is because the engine output torque obtained for the same intake air amount increases as the alcohol concentration increases (see FIG. 4).

In the next step 5, the engine load parameter TQ1 as the intake air amount calculated in step 3 is added to the correction coefficient CO calculated in step 4 based on the alcohol concentration.
MET is multiplied, and the result is finally set in TQSEN as a parameter representing the engine load. Even if the intake air amount parameter TQ1 is the same, if the alcohol concentration in the fuel supplied to the engine at that time changes, the obtained engine output torque changes, so the intake air amount parameter TQ1. Is not a parameter that accurately represents the engine output torque, but the intake air amount parameter TQ1 is a correction coefficient CO based on the alcohol concentration.
By correcting with MET, the engine output torque can be used as an engine load parameter that accurately represents.

In the next step 6, the line pressure is set on the basis of the engine load parameter TQSEN corrected and set on the basis of the alcohol concentration as described above, and the line pressure in the control valve group 5 is set so as to obtain this line pressure. Control the valve that regulates the line pressure. The line pressure needs to be set larger as the input torque to the transmission is larger, but the engine load parameter TQSEN is
Since the value corresponds to the output torque change due to the alcohol concentration change, it is possible to set the line pressure corresponding to the request in this step 6, and it is possible to prevent the friction element from slipping due to the insufficient line pressure or the shift shock due to the excessive line pressure. It can be prevented in advance.

Although the line pressure is set based on the engine load parameter TQSEN in the above embodiment, the automatic shift position may be determined instead of or at the same time as the line pressure setting. That is, for example, a shift pattern map in which a shift position is set using the engine load parameter TQSEN and the vehicle speed VSP detected by the vehicle speed sensor 11 as parameters is stored in advance, and the map is set as described above. The shift position may be determined by referring to the load parameter TQSEN and the vehicle speed VSP. In this case as well, the parameters (the intake air amount and the throttle valve opening) that directly represent the cylinder intake air amount are set to the engine load. When using as a representative parameter, it becomes possible to determine the shift position corresponding to the change in the output torque due to the change in the alcohol concentration, and the shift can be performed at the optimum position.

Further, in the present embodiment, the intake air flow rate Q detected by the air flow meter 8 is divided by the engine speed N as a parameter representative of the engine load and related to the engine intake air amount. Although the intake air amount per unit rotation of the engine that is used is used, the opening of the throttle valve 7 or boost may be used. When using the throttle valve opening or boost, these parameters may be set to alcohol. It may be configured so that the correction is performed according to the density.

[0027]

As described above, according to the present invention, in an automatic transmission combined with an engine capable of using different kinds of fuel such as alcohol and gasoline, the parameter related to the engine intake air amount represents the engine load. Even when detected as a parameter, it is possible to respond to a change in engine output torque due to a change in alcohol concentration, and it is possible to optimally control the line pressure and the shift position even if the alcohol concentration changes.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a system schematic diagram showing an embodiment of the present invention.

FIG. 3 is a flowchart showing how the line pressure is set in the above embodiment.

FIG. 4 is a diagram showing a change in engine output torque due to a difference in alcohol concentration.

[Explanation of symbols]

 1 engine 2 automatic transmission 3 torque converter 4 gear type transmission 5 control valve group 6 control unit 7 throttle valve 8 air flow meter 9 crank angle sensor 10 output shaft 11 vehicle speed sensor 12 alcohol concentration sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiromitsu Yamaura 1716 1 Kasukawa-cho, Isesaki-shi, Gunma 1 NIPPON ELECTRONICS CO., LTD. (72) Tomoyuki Hirose 167-1 Kasukawa-cho, Isesaki-City, Gunma NIPPON ELECTRIC Co., Ltd. (72) Inventor Takafumi Fukumoto, 1671 Kasugawa-cho, Isesaki-shi, Gunma Nippon Electronic Equipment Co., Ltd.

Claims (1)

[Claims] 1. A control device for an automatic transmission for a vehicle, wherein an engine combined with an automatic transmission is an engine that can be used by switching or mixing different kinds of fuels, wherein Reference fuel concentration detecting means for detecting a reference fuel concentration, engine load parameter detecting means for detecting a parameter representative of the engine load and related to the intake air amount of the engine, and the engine load parameter detecting means Engine load parameter correcting means for correcting a parameter representative of the engine load detected by the means based on the concentration detected by the reference fuel concentration detecting means, and based on the engine load parameter corrected by the engine load parameter correcting means A control device for an automatic transmission for a vehicle, comprising: a control means for controlling the automatic transmission;