JPH0533687A - Torque down control device for automatic transmission for vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] Stable reduction of shift shock in an automatic transmission combined with an engine in which alcohol-blended fuel is used, regardless of alcohol concentration. [Structure] The engine output torque is reduced at the time of gear shift, thereby suppressing the occurrence of gear shift shock. Here, the alcohol concentration in the fuel supplied to the engine is detected, and the engine load condition that determines the torque down control region is variably set based on the alcohol concentration and the type of gear shift (S1). In addition, a vehicle speed condition for setting the torque down control region is set based on the type of shift (S2). Then, the torque down control region is finally set based on the engine load condition and the vehicle speed condition (S3), and the engine output torque is reduced when the gear shift is performed in this torque down control region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque down control device for an automatic transmission for a vehicle, and more particularly to a technique for reducing an output torque of an engine to reduce a shift shock during a gear shifting operation in the automatic transmission.

[0002]

2. Description of the Related Art Conventionally, during a gear shifting operation of an automatic transmission for a vehicle, the ignition timing of the engine is retarded to reduce the output torque of the engine, so that the output shaft torque of the transmission during the gear shifting (vehicle drive There is one that suppresses a sudden change in torque to mitigate a shift shock (Japanese Patent Application No. 1-32).
5798).

In the conventional gear shift shock reducing apparatus based on the ignition timing retard control, for example, during the gear shifting operation, for example, the throttle valve opening TVO is set in a torque down control region which is set in advance as a region equal to or larger than a predetermined opening. When the gear shift is applicable and a gear shift is performed, a request to reduce the engine output torque is generated, and the ignition timing is retarded by a preset retard angle amount to reduce the output torque of the engine to reduce the transmission torque. The change in output shaft torque is suppressed.

[0004]

By the way, in recent years, development of an internal combustion engine in which alcohol is used as an alternative fuel to gasoline has been advanced (Japanese Patent Laid-Open No. 56-9854).
No. 0, 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.

Here, in the case where an internal combustion engine and an automatic transmission, which can be used by switching gasoline and alcohol or by mixing them, are combined as described above, the engine output torque at the time of shifting as described above is of course required. If an attempt is made to reduce the engine output, the engine output torque will differ in an engine using alcohol fuel even if the load is equal (throttle valve opening, equal boost, equal intake air amount) due to changes in alcohol concentration. Therefore, in the control based on the torque-down control area that is fixed in advance, the following problems occur.

That is, assuming that the fixed torque down control region shown by the dotted line is preset on the automatic shift pattern as shown in FIG. 4, for example, at the point B on the shift line from the first speed to the second speed. As shown in FIG. 5, the torque down control at the point B is suitable when the alcohol concentration is high and can reduce shift shock, but 100% gasoline is used. In the case of using, the unnecessary shift-down control shortens the shift time excessively, resulting in a large shift shock.

On the other hand, at the point A on the same shift line from the first speed to the second speed, the torque down control is not performed, but when the alcohol concentration is high, the torque down control is not performed as shown in FIG. If the 100% gasoline is used, on the contrary, not performing the torque down control at the point A will result in the desired gear shifting operation. Therefore, the point A is not in the torque down control range here,
When the alcohol concentration is high, it is necessary to perform torque reduction.

As described above, even if a fixed torque down control region is set, such a set region does not correspond to all alcohol concentration states, and the torque down control is unnecessarily performed depending on the change in alcohol concentration. In some cases, this may result in an increase in shift shock, or torque down control may not be performed when necessary to extend the shift time, impairing the durability of the shift element.

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 engine output characteristic changes. Even so, it is an object of the present invention to provide a torque down control device for an automatic transmission for a vehicle, which can appropriately execute torque down control at the time of shifting.

[0010]

Therefore, a torque down control device for an automatic transmission for a vehicle according to the present invention is configured to transmit the output torque of the engine to a speed change mechanism through a torque converter, and the engine is also provided. 1 is a torque down control device for an automatic transmission for a vehicle, which is an internal combustion engine that can use different types of fuel by switching or mixing them, and is configured as shown in FIG.

In FIG. 1, the torque down determination means is
A torque down control region in which the output torque of the engine is reduced during a gear shift operation is determined based on operating conditions. Further, the shift detecting means detects a shift operation in the shift mechanism. The torque down means reduces the engine output torque when the torque down determination means determines the torque down control range and the shift detection means detects the shift operation.

Here, the torque down control area changing means is arranged in the torque down control area in the torque down judging means in accordance with the concentration of the reference fuel in the fuel supplied to the engine detected by the reference fuel concentration detecting means. Change.

[0013]

That is, since the internal combustion engine combined with the automatic transmission to which the present invention is applied is an internal combustion engine that can be used by switching or mixing different kinds of fuel, the mixing ratio of the different kinds of fuel (the different kinds of fuel is changed). The torque down control area can be automatically changed in response to changes in the engine output torque due to changes in the engine output torque. The control is performed appropriately.

[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.
The gear-type transmission 4 (transmission mechanism) transmitted through the gear-type transmission 4 and a hydraulic actuator 5 for performing connection / disconnection operations of various transmission elements in the gear-type transmission 4. The operating hydraulic pressure for the hydraulic actuator 5 is on / off controlled via various electromagnetic valves (not shown).

Signals from various sensors are input to the control unit 6. As the various sensors, a throttle sensor 8 for detecting the opening TVO of the throttle valve 7 of the intake system of the engine 1 is provided. Further, a vehicle speed sensor 10 for detecting a vehicle speed VSP by obtaining a rotation signal from the output shaft 9 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 for detecting an alcohol concentration as a reference fuel in the mixed fuel. A sensor 11 is provided. The alcohol concentration sensor 11 as the reference fuel concentration detecting 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 11 The fuel supply amount of the engine 1 is electronically controlled on the basis of the concentration, and the alcohol concentration is used as control information in torque down control at the time of gear shift in the configuration according to the present invention.

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 engine control unit and the automatic transmission control unit may be separately provided so that they can communicate with each other.

In the automatic transmission control CPU of the control unit 6, the select lever is driven in the drive range (D) based on the operation position signal of the select lever operated by the driver.
Range), the throttle valve opening TVO and the vehicle speed V
According to SP, the shift positions of the first to fourth speeds are automatically set, and automatic shift control is performed to control the gear type transmission 4 to the shift position via the hydraulic actuator 5.

That is, the shift pattern map is set in advance based on the throttle valve opening TVO representing the engine load and the vehicle speed VSP, and corresponds to the actual opening TVO and the vehicle speed VSP detected by the sensor. The shift position is referred to from the shift pattern map, and when the current shift position is different from the shift position corresponding to the operating condition obtained from the map, the shift position is changed to the shift position referred to in the map. is there.

In addition to the automatic shift control as described above, in the present embodiment, in order to prevent the output torque (driving torque) at the output shaft 9 from suddenly changing during the shift operation to cause a shift shock, the engine is not operated during the shift operation. Control to forcibly reduce the output torque. Here, the torque down control at the time of shifting described above, which is performed by the automatic transmission control CPU of the control unit 6, will be described with reference to the flowchart of FIG. In this embodiment, the control unit 6 is provided with the functions of the torque down judging means, the torque down means, the torque down control area changing means, and the gear shift detecting means by software as shown in the flowchart of FIG. I shall.

In the flow chart of FIG. 3, first, in step 1 (denoted as S1 in the figure; the same applies hereinafter),
Based on the alcohol concentration detected by the alcohol concentration sensor 11 and the type of shift, the engine load width a for determining the torque down control region is obtained by referring to a preset map. The engine load width a determines the high load region in which the torque down control is executed with reference to the full load state of the engine. Therefore, if the engine load width a becomes large, the torque down control is executed from the low load region.

Here, by variably setting the engine load width a according to the alcohol concentration as described above, it is possible to set the torque down region according to the alcohol concentration. That is, if the alcohol concentration in the fuel becomes higher, the engine output will increase further under the equal load condition, and the torque reduction request will increase accordingly. Therefore, the higher the alcohol concentration,
In this embodiment, the engine load change width a is set to be larger as the alcohol concentration is higher so that the torque reduction can be executed from the lower load side.
Therefore, even if the alcohol concentration in the fuel supplied to the engine 1 changes, an appropriate torque down control region can be set in response to the change, and the torque down control can be reliably performed when necessary. It will be possible.

Incidentally, as in the present embodiment, the shift pattern map uses the throttle valve opening TV as a value representing the engine load.
When O is used, the engine load width a corresponds to the opening width ΔTVO of the throttle valve 7, and torque down control is performed from the full opening of the throttle valve 7 to the high opening area of the opening width. Will be done. In the next step 2, the vehicle speed VSP condition in the torque down control region is set according to the type of shift. For example, when the torque reduction during shifting from the first speed to the second speed is to be performed when the vehicle speed VSP is 30 km / h or more, if the torque reduction is 30 km / h,
Is stored in advance as the reference vehicle speed VSPs corresponding to the shift from the first speed to the second speed.

Then, in step 3, based on the engine load condition set according to the alcohol concentration in step 1 and the vehicle speed condition VSPs set in step 2, finally, the torque down control region (shaded line in FIG. 3) is obtained. Set). Therefore, in the case of the present embodiment, a region where the engine load (throttle valve opening TVO) is equal to or greater than a predetermined value and the vehicle speed VSP is the predetermined speed VSPs for each type of shift is the torque down control region.

In step 4, it is judged whether or not the conditions of the current vehicle speed VSP and the engine load (throttle valve opening TVO) are included in the torque down control range. Go to step 5 and perform the actual shift operation (torque down execution period during shift period)
If it is determined that the gear shift is performed in the torque down control range, the process proceeds to step 6 and a torque down request signal is sent from the automatic transmission control CPU side to the engine control C
Output to PU side.

In the gear shifting operation, for example, a change in the engine speed N after the control of the hydraulic pressure for the hydraulic actuator 5 is started based on a gear shift request, a change in the output shaft torque of the transmission, and further, , Is detected based on the speed ratio of the torque converter 3 and the like. On the other hand, if it is not during the gear shifting operation, or if it is not within the torque down control region even during the gear shifting operation, step 6 is skipped and the present program is ended as it is.

The engine control CPU, which has received the torque down request signal, controls the output torque of the engine to be reduced during the gear shifting operation by retarding the ignition timing, controlling the fuel cut, and the like. Controls the occurrence of shock. The vehicle speed condition setting in the torque down control area in step 2 in the flowchart of FIG. 3 may be omitted. Further, in a simple manner, the engine load condition for determining the torque down control region may be variably set using only the alcohol concentration as a parameter, regardless of the type of shift.

In this embodiment, the case where alcohol and gasoline are mixed and used is shown. However, alcohol and gasoline may be switched and used. In this case, basically, The torque down control region for alcohol and the torque down control region for gasoline may be set individually.

[0029]

As described above, according to the present invention, in an automatic transmission which is combined with an engine capable of using different fuels such as alcohol and gasoline, the engine output torque is reduced during a gear shift operation to cause a gear shift shock. The torque down control can be performed under an appropriate condition according to the fuel change when suppressing the torque change, and variations in the occurrence of shift shock and deterioration of durability occur with the fuel change (change of the reference fuel concentration). This has the effect of preventing this.

[Brief description of drawings]

FIG. 1 is a block diagram showing a 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 a torque down control area is set.

FIG. 4 is a diagram showing a conventional torque down control region.

FIG. 5 is a time chart showing an example of a case where torque down control becomes unnecessary depending on the alcohol concentration.

FIG. 6 is a time chart showing an example of the case where torque down control is required depending on the alcohol concentration.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 3 Torque Converter 4 Gear Transmission 5 Hydraulic Actuator 6 Control Unit 7 Throttle Valve 8 Throttle Sensor 9 Output Shaft 10 Vehicle Speed Sensor 11 Alcohol Concentration Sensor

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location F16H 61/04 8207-3J // F16H 63:40 8207-3J (72) Inventor Hideki Sekiguchi Kasukawa, Isesaki City, Gunma Prefecture 1671, Machi 1 Nihon Denki Kiki Co., Ltd. (72) Inventor Tomoyuki Hirose 1671 1 Kasukawa-cho, Isesaki-shi Gunma Pref. Within Nippon Electronic Equipment Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. An internal combustion engine configured to transmit the output torque of the engine to a speed change mechanism via a torque converter, and which can be used by switching or mixing different types of fuel. A torque down control device for an automatic transmission for a vehicle, comprising: a torque down determining means for determining a torque down control region for reducing an output torque of an engine during a gear shifting operation based on operating conditions; and a gear shifting operation in the gear shifting mechanism. A shift detecting means for detecting the torque, a torque down means for reducing the engine output torque when the torque down determining means determines the torque down control area, and a shift operation is detected by the shift detecting means; And a reference fuel concentration detecting means for detecting the concentration of the reference fuel in the fuel supplied to the Torque down control range changing means for changing the torque down control area in the torque down determining means in accordance with the concentration of the reference fuel stored, and a torque down control for an automatic transmission for a vehicle. apparatus.