JP2913953B2 - Transmission control device for automatic transmission in power train - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission in a power train in tandem connection with an engine having variable output characteristics and an automatic transmission.

[0002]

2. Description of the Related Art As an engine with variable output characteristics, for example, as disclosed in Japanese Patent Application Laid-Open No. 3-111610, an output characteristic with respect to a throttle opening degree is determined by selectively using a plurality of engine intake / exhaust valve control cams. There is known a so-called variable valve type engine capable of switching between the two. This engine is provided with three types of cams for each intake and exhaust valve, and these cams, that is, fuel efficiency cams (hereinafter referred to as P cams, hereinafter referred to as P cams) which emphasize fuel efficiency at the time of partial engine load as shown in FIG. ), And a low-speed cam (hereinafter, referred to as L cam) useful during low rotation and a high-speed cam (hereinafter, referred to as H cam) useful during high rotation. Depending on the amount of depression, and the vehicle speed (engine speed), they are properly used to match the current driving state. As shown in FIG. 3, which shows the output characteristics when the throttle is fully opened, the engine can switch the output characteristics when using the P cam, when using the L cam, and when using the H cam.

[0003] On the other hand, an automatic transmission is a diagram which is preset as a combination of an engine throttle opening TVO and a vehicle speed V as seen in, for example, a RE4R01A type automatic transmission which is being developed and used by the present applicant (see the maintenance manual). Based on the shift pattern exemplified in FIG. 4, a suitable shift speed is determined, and various frictional elements (clutches, brakes) are selectively hydraulically actuated (fastened) so that the optimum shift speed is selected.
It is customary to let them.

[0004]

However, in such a power train in which the engine and the automatic transmission are connected in tandem, when the accelerator pedal is mechanically connected to the throttle valve of the engine, the switching of the cam is not performed. There is a certain correlation between the accelerator pedal depression amount used and the engine throttle opening used for the shift pattern, and the engine load parameter used for the cam switching control and the engine load parameter used for the shift control match. However, if the accelerator pedal is not mechanically connected to the throttle valve of the engine and the throttle opening is electronically controlled according to the accelerator pedal depression amount operated by the driver and other vehicle operating conditions, the throttle opening Does not necessarily correspond to the amount of depression of the accelerator pedal. For non-stuff (opening determined by the fixed correlation), and parameters related to the engine load is used for switching control of the cam, and a parameter related to engine load used for shift control different.

For this reason, when the above-mentioned conventional shift control is applied to an automatic transmission combined with the latter engine having an electronically controlled throttle valve, a cam selected according to an accelerator pedal depression amount indicating a driver's intention is used. This means that gear shifting control in consideration of the type (actual engine output) has not been performed, and it has been confirmed that the following problems will occur. That is, the engine output differs depending on the selected cam (engine output characteristic) even under the same throttle opening as shown in FIG. 3, and as described above, the gear is changed only by the throttle opening and the vehicle speed without considering the selected cam. In a conventional automatic transmission that performs control, the selected gear is not necessarily a suitable gear that matches the engine output.

According to the present invention, the parameter relating to the engine load relating to the shift pattern of the automatic transmission is set to be the same as the parameter relating to the engine load used for switching the engine output characteristic. Therefore, an object of the present invention is to solve the above-described problem.

[0007]

SUMMARY OF THE INVENTION To this end, a shift control device for an automatic transmission according to the present invention is provided with a plurality of electronically controlled throttle opening degrees in accordance with an accelerator stroke operated by a driver and other vehicle operating conditions. In a power train that is in tandem with an output characteristic variable engine that switches and uses the output characteristic of the engine according to an accelerator stroke, and an automatic transmission that is controlled to be shifted based on a shift pattern set in advance as a combination of certain parameters, An accelerator stroke used in the switching control of the output characteristics is set as a parameter relating to the engine load of the shift pattern.

[0008]

The throttle opening of the engine is electronically controlled according to the accelerator stroke operated by the driver and other vehicle operating conditions. The engine is used to switch the output characteristic with respect to the throttle opening in accordance with the accelerator stroke, generates power determined by the output characteristic, and inputs the power to the automatic transmission.

On the other hand, an automatic transmission shifts and outputs engine power at a gear ratio corresponding to a selected shift speed, and the shift control device includes the shift speed including an accelerator stroke used for switching engine output characteristics. It is determined based on a shift pattern set in advance as a combination of parameters.
Therefore, in the shift control of the automatic transmission, the accelerator stroke used when the engine output characteristic is switched is used as the engine load parameter. As a result, regardless of the selection of the engine output characteristic with respect to the throttle opening, the selected engine is selected. Since the shift control is performed in consideration of the output characteristics, the selected shift speed can always be set to a suitable shift speed that matches the engine output, even though the engine output differs depending on the output characteristics. In addition, since the accelerator stroke commonly used in the switching control of the engine output characteristics and the shift control of the automatic transmission directly represents the driver's will, the driver's will is reliably reflected in both controls. The above-mentioned effects can be achieved without sacrificing in this regard.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a power train control system showing one embodiment of a shift control device according to the present invention, wherein 1 is an engine with variable output characteristics and 2 is an automatic transmission. In the present embodiment, it is assumed that the automatic transmission is appropriately gear-shift-controlled in these tandem-connected power trains.

The engine 1 burns the injected fuel by the air sucked from the air cleaner 3 via the throttle valve 4, inputs the resulting power to the automatic transmission 2, and outputs the combustion exhaust gas from the exhaust pipe 5 to the outside. To be released. By the way, the engine 1 is not mechanically connected to the accelerator pedal 6 operated by the driver, but is electronically controlled via the throttle actuator 7, and the above-described intake and exhaust is performed in time with the engine. Japanese Patent Laid-Open No. 3-111161 as described above with reference to FIGS.
A variable valve as described in Japanese Patent Application Publication No. 0-305, and the three types of cams are switched by a cam switching mechanism 8.

The automatic transmission 2 changes the rotational power from the engine 1 at a gear ratio corresponding to the selected gear and transmits it to the output shaft 9 for driving the wheels of the vehicle. For example, Nissan Motor Co., Ltd. RE4R01A type automatic transmission maintenance manual ", and the speed is electronically controlled via the control valve 10.

Control of the opening of the throttle valve 4 (throttle opening TVO) via the throttle actuator 7 is performed by the throttle control means 11, and control of cam switching via the cam switching mechanism 8 of the engine 1 is performed by cam switching. This is performed by the control means 12, and the shift control via the control valve 10 of the automatic transmission is performed by the shift control means 13.

The throttle control means 11 receives a signal from an accelerator stroke sensor 14 for detecting a stroke AST of the accelerator pedal 6 and various operating state signals.
Throttle opening T via throttle actuator 7
The VO is basically controlled to the opening amount corresponding to the depression amount of the accelerator pedal 6, that is, the accelerator stroke AST, but is appropriately adjusted according to the driving state to realize a throttle opening that is consistent as is well known. Shall be.

The cam switching control means 12 includes a signal AST from an accelerator stroke sensor 14 and a vehicle speed sensor 15
, And a suitable cam is obtained based on a map set in advance as a two-dimensional parameter of these signals.
By supplying the corresponding cam command CAM to the cam switching mechanism 8, the engine 1 selects a suitable cam.

The shift control means 13 receives the signal AST from the accelerator stroke sensor 14 and the signal V from the vehicle speed sensor 15 similarly to the cam switching control means 12,
A shift speed suitable for the driving state is determined based on a shift pattern set in advance as a two-dimensional map of the accelerator stroke AST and the vehicle speed V, and a corresponding command SFT is supplied to the control valve 10 to change the shift speed to an automatic transmission. Let 2 be selected.

Since the accelerator stroke AST and the vehicle speed V used for switching the cams are used as parameters of the shift pattern as they are, and the shift control is performed based on the shift pattern, the selected cam is considered in the shift control. In other words, even if the engine output differs depending on the cam, the selected shift speed can always be set to a suitable one that matches the engine output. It should be noted that an accelerator stroke A indicating the driver's will is used instead of the conventional throttle opening.
Since ST is used as a parameter of the shift pattern, even if the throttle opening TVO may be deviated from the value corresponding to the stroke AST of the accelerator pedal 6 due to the electronic control throttle, the throttle opening TVO responds to this throttle opening TVO. As a result, the automatic transmission 2 is not shifted independently of the driver's intention, and such a feeling of strangeness can be eliminated.

[0018]

As described above, in the shift control device of the present invention, the accelerator stroke AST used in the switching control of the output characteristics of the engine with the electronically controlled throttle is used as a parameter relating to the engine load in the shift pattern. The parameters related to the engine load are the same in the switching control of the output characteristics and the shift control, so that the shift is performed in consideration of whatever characteristics are selected as the engine output characteristics with respect to the throttle opening TVO. In spite of the fact that the engine output varies depending on the output characteristics, the selected gear can always be set to a suitable one that matches the engine output. In addition, since the accelerator stroke commonly used in the switching control of the engine output characteristics and the shift control of the automatic transmission directly represents the driver's will, the driver's will is surely reflected in the above two controls. And the above-mentioned effects can be achieved without sacrificing in this regard.

[Brief description of the drawings]

FIG. 1 is a block diagram of a power train control system showing one embodiment of a transmission control device of the present invention.

FIG. 2 is an operation characteristic diagram of three types of intake and exhaust valve cams.

FIG. 3 is an output performance diagram of the engine when the cam is used properly.

FIG. 4 is a conventional shift pattern diagram of an automatic transmission.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 engine 2 automatic transmission 3 air cleaner 4 throttle valve 5 exhaust pipe 6 accelerator pedal 7 throttle actuator 8 cam switching mechanism 9 transmission output shaft 10 control valve 11 throttle control means 12 cam switching control means 13 shift control means 14 accelerator stroke sensor 15 Vehicle speed sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // F16H 59:18 59:44 (56) References JP-A-2-303937 (JP, A) JP-A-1-105048 ( JP, A) JP-A-64-80733 (JP, A) JP-A-60-40723 (JP, A) JP-A-2-264134 (JP, A) JP-A-5-99305 (JP, A) JP JP-A-5-44508 (JP, A) JP-A-5-71371 (JP, A) JP-A-5-104991 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 59 / 00-61/12 F16H 61/16-61/24 F16H 63/40-63/48 B60K 41/00-41/28 F02D 13/02 F02D 29/00-29/06 F02D 41/04

Claims (1)

(57) [Claims] An output characteristic variable engine for switching a plurality of output characteristics for a throttle opening electronically controlled in accordance with an accelerator stroke operated by a driver and other vehicle operating conditions in accordance with the accelerator stroke, and a certain parameter In a power train that is in tandem with an automatic transmission that is shifted based on a shift pattern that is set in advance as a combination of the following, an accelerator stroke used in the switching control of the engine output characteristic is set as a parameter related to an engine load of the shift pattern. A shift control device for an automatic transmission in a power train, comprising: