JPH06336946A - Integrated control device for engine and automatic transmission - Google Patents

Abstract

PURPOSE:To improve the utmost fuel consumption performance while securing the desired output by providing a control means for outputting a speed change command to a speed change means to maintain the same power without changing the objective air/fuel ratio. CONSTITUTION:A control unit 40 outputs various control signals on the basis of signals from an engine speed sensor, an airflow meter 11, a throttle opening sensor 16, a water temperature sensor 41, an O2 sensor 38, a turbine sensor 42, and the like. The control unit 40 also outputs a control signal to a solenoid valve for controlling the hydraulic circuit of an automatic transmission to obtain a specified shift position. When an air/fuel ratio change inhibiting means outputs a signal to inhibit the objective air/fuel ratio, the control unit 40 outputs a speed change command to a speed change means so as to maintain the same power without changing the objective air/fuel ratio. The upmost fuel consumption performance is thus improved while securing the desired output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for comprehensively controlling an air-fuel ratio of an engine and an automatic transmission connected to the engine.

[0002]

2. Description of the Related Art There is known an engine control device that performs so-called air-fuel ratio control in which a target air-fuel ratio is set according to an operating state and fuel supply control is performed so as to achieve this target air-fuel ratio. In this air-fuel ratio control, the air-fuel ratio is controlled to be leaner than the stoichiometric air-fuel ratio in a predetermined operating region in order to improve fuel efficiency. Further, in another predetermined operation region, the fuel amount is increased and the operation is performed on the rich side of the stoichiometric air-fuel ratio so that the desired output is controlled.

Further, in the control of the automatic transmission, the shift operation is automatically performed by operating the shift mechanism in the automatic transmission based on the shift map. The shift map is provided with a shift control line set according to the driving state, and when the driving state changes beyond the shifting line, a predetermined shifting operation is automatically generated.

In an engine equipped with such an automatic transmission and adapted to perform air-fuel ratio control of an engine, when the accelerator pedal is depressed to perform an acceleration operation while operating in a lean state, the air-fuel ratio is increased. In the control, the opening of the throttle valve is increased to achieve the output demand, and the operating range is changed, so that the fuel amount is increased and the air-fuel ratio shifts to the rich side. At the same time, in the shift control of the automatic transmission, the shift operation is carried out when the shift line is crossed due to the change of the operating region.

As described above, the air-fuel ratio control and the automatic transmission control are performed independently of each other even though the predetermined operation is performed by paying attention to the change in the operating state. Therefore, it cannot be said that the optimum air-fuel ratio control and automatic transmission control for achieving the predetermined output request are not necessarily performed. That is, when a predetermined output request is made, the conventional system is not configured to comprehensively monitor the air-fuel ratio control and the automatic transmission so as to achieve the minimum fuel consumption.

In a vehicle equipped with an automatic transmission and an engine for performing air-fuel ratio control, Japanese Unexamined Patent Publication (Kokai) No. 4-252831 discloses an engine air-fuel ratio control system in which a fuel amount is increased in a slow acceleration state from the viewpoint of fuel economy. There is disclosed an air-fuel ratio control device in which the fuel increase correction map is switched according to the gear ratio so that the occurrence of the above will not occur.

[0007]

[Problems to be Solved] However, the above-mentioned Japanese Patent Laid-Open No. 4-25
In the one disclosed in Japanese Patent No. 2831, there is a disadvantage that the capacity of the memory of the electronic control unit becomes large because it is necessary to store a plurality of maps, and the control of the automatic transmission and the control of the air-fuel ratio are still performed separately. As I was told, I still have some complaints about fuel efficiency.

Therefore, the present invention has been made in view of the above circumstances.
An object of the present invention is to provide an air-fuel ratio control device and an integrated control device for an automatic transmission, which can improve fuel efficiency as much as possible while ensuring a desired output.

[0009]

In order to achieve the above object, an integrated control system for an engine and an automatic transmission according to the present invention is constructed as follows. The present invention relates to an engine, an automatic transmission coupled to the engine, an air-fuel ratio detecting means for detecting an air-fuel ratio of fuel supplied to the engine, and an air-fuel ratio setting for setting an air-fuel ratio corresponding to an operating region of the engine. Means and
Air-fuel ratio control means for controlling the air-fuel ratio of the fuel to be supplied to the air-fuel ratio to a predetermined value so as to achieve the target air-fuel ratio set by the air-fuel ratio setting means according to the operating state, and responding to changes in the operating state And a shift means for performing a shift operation in the automatic transmission, a determining means for determining whether or not a change in the target air-fuel ratio based on a change in the operating region due to a change in the operating state occurs, and a change in the target air-fuel ratio by the determining means. When it is determined that the target air-fuel ratio is changed, an air-fuel ratio change prohibiting means for prohibiting a change in the target air-fuel ratio and a signal for prohibiting a change in the target air-fuel ratio is output by the speed change means. And a control means for maintaining the same power without changing the target air-fuel ratio by outputting a command.

[0010] Typically, the change in the operating range is a change from a lean region in which the target air-fuel ratio is set to be leaner than the stoichiometric air-fuel ratio to a stoichiometric air-fuel ratio region in which the target air-fuel ratio is set to the stoichiometric air-fuel ratio. is there. Further, in a preferred mode, when the automatic transmission is in the lockup state, the operation of the air-fuel ratio change prohibiting means is stopped and the change of the target air-fuel ratio is allowed.

According to another feature, the air-fuel ratio change prohibition is prohibited when the operating region after the gear shifting operation is predicted and the operating state realized in the operating region does not satisfy a predetermined condition. The operation of the means is stopped and the change of the air-fuel ratio is allowed. In a preferred mode, the control device of the present invention further includes a fuel consumption detecting means for detecting fuel consumption, compares the fuel consumption after the change of the driving range with the fuel consumption after the gear shift operation, and based on this result, changes the target air-fuel ratio or It is designed to perform one of gear shifting operations.

For example, the fuel consumption detecting means may be constructed by detecting the intake negative pressure. In another aspect, the fuel consumption detecting means is a means for detecting an accelerator opening degree.

[0013]

According to the present invention, the target air-fuel ratio is set according to the operating condition. Specifically, the air-fuel ratio map of the same target air-fuel ratio is set by dividing the region for the operating state defined by the engine speed and the engine load, and a different target air-fuel ratio is set every time the operating region changes beyond that segment. Is set.

In this case, the target air-fuel ratio is given on the lean side, which is leaner than the theoretical air-fuel ratio, in the relatively low-load low-rotation region, and the load and rotational speed are increased, so that the air-fuel ratio is set to the theoretical air-fuel ratio in the normal region. To be done. Further, when the load and the rotational speed increase, a rich side target air-fuel ratio that is richer than the theoretical air-fuel ratio is set in order to cope with the output request.

Further, similarly to the above, the shift control in the automatic transmission includes a shift map provided with a shift control line for generating a predetermined shift according to an operating state defined by the engine load, the engine speed, the vehicle speed and the like. According to. Regarding the relationship between the air-fuel ratio control and the automatic transmission control, when the air-fuel ratio control and the gear shift control are performed under a certain condition, they are independently performed based on the respective maps.

However, in the operating state in which the target air-fuel ratio is set to the lean side of the stoichiometric air-fuel ratio, if the acceleration operation is performed and the lean region is to be exceeded, the target air-fuel ratio must be changed. This is not permitted, and the shift operation of the automatic transmission is performed. That is, the basic feature of the present invention is that the air-fuel ratio control and the shift control are associated with each other under certain conditions.

The reason for this is as follows. The fact that the target air-fuel ratio is set to the rich side means that the fuel amount is increased, and the fuel consumption deteriorates accordingly. Therefore, it is desirable to keep the target air-fuel ratio as lean as possible as long as the output request is constant. In the present invention, the operating region changes from the operating state in which the target air-fuel ratio on the lean side is set, and the target air-fuel ratio is focused on the same horsepower line, and if there is an output request along this line, as much as possible Priority is given to lean control of the air-fuel ratio, and change of the target air-fuel ratio from the lean operation region to the rich side is prohibited. At the same time, the automatic transmission is forcibly shifted so that the same horsepower as in the case where the change of the air-fuel ratio has occurred can be ensured within the lean operation range of the air-fuel ratio.

Thus, the basic feature of the present invention is to limit the shift of the air-fuel ratio from the lean region to the rich side, but there are exceptions under specific conditions. For example, when the automatic transmission is in the lockup state, the target air-fuel ratio can be changed. This is because it is considered that the influence of energy loss in power transmission under the torque converter state is greater than the deterioration of fuel efficiency due to the change of the air-fuel ratio to the rich side.

In addition, in general, the operating region after the gear shifting operation is predicted, and when the operating state realized in the operating region does not satisfy the predetermined condition, the change of the air-fuel ratio is allowed. I am For example, in an operating region where the pumping loss is larger than in the stoichiometric air-fuel ratio operating state even in the lean operating state, the air-fuel ratio may be allowed to be changed. This is because there may be an ultimate advantage in terms of fuel economy. Therefore, conversely, even when the stoichiometric air-fuel ratio operating state is changed to the lean operating state, if the pumping loss becomes large and the fuel consumption deteriorates, the change is prohibited.

Further, one step further, a fuel consumption detecting means for detecting the fuel consumption is provided, and the fuel consumption after the change of the driving range is compared with the fuel consumption after the gear shift operation. Based on the result, the target air-fuel ratio is changed or the gear shift operation is performed. You can go. In this case, the fuel consumption is estimated by focusing on factors that have a strong correlation with the fuel consumption, such as intake negative pressure and throttle opening, and control is performed using this factor as a barometer, which simplifies the control and provides an appropriate result. Can be obtained.

For example, the fuel consumption detecting means may be constructed by detecting the intake negative pressure. In another aspect, the fuel consumption detecting means detects the accelerator opening degree.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an overall configuration diagram of an engine according to an embodiment of the present invention. The engine 1 includes a piston 3 that slides inside a cylinder 2. The piston 3 is connected to the crankshaft 5 via the connecting rod 4. A combustion chamber 6 is formed above the piston 3. The intake port 7 and the exhaust port 8 communicating with the combustion chamber 6 are provided with an intake valve 9 and an exhaust valve 10 for opening and closing the intake port 7 and the exhaust port 8.

An air cleaner 12 is provided at the most upstream side of the intake passage 11 of the engine 1, an air flow meter 13 is provided downstream thereof, and a throttle valve 14 is provided downstream thereof. The opening of the throttle valve 14 is adjusted by an actuator 15 having a servo motor, and the opening is detected by a throttle opening sensor 16.

The intake system of this embodiment is provided with a bypass passage 17 that bypasses the throttle valve 14. The bypass passage 17 controls the intake air amount during idle operation to control the engine speed. An idle speed control valve 18 for controlling is provided. Throttle valve 1
4, a surge tank 19 is provided downstream of the surge tank 19, and the intake passage of each cylinder downstream of the surge tank 19 is branched into a primary intake passage 20 and a secondary intake passage 21. And 1
An injector 22 for injecting fuel is provided in the vicinity of the combustion chamber 6 of the secondary intake passage 20, and a control valve 23 for controlling the opening of the secondary intake passage 21 is provided at the upstream end portion of the secondary intake passage 21 for intake. Make up the system. Negative pressure from the surge tank 19 is introduced into the actuator 24 that controls the opening degree of the control valve 23 through the negative pressure passage 25.
Is provided with a three-way valve 26 that controls the introduction negative pressure.

The injector 22 is connected to a fuel tank 28 via a fuel supply passage 27. A fuel filter 29 is provided in the fuel supply passage 27. Alternatively, a fuel return passage 30 is connected to the injector 22 to return excess fuel to the tank. The return passage 30 is provided with a pressure adjusting valve 31 for adjusting the pressure of fuel. Further, an evaporative fuel passage 32 is connected to the fuel tank 28 for treating the evaporative fuel, and this passage is connected to the surge tank 13 via a two-way valve 33 and a canister 34.

A fuel pump 35 is arranged in the fuel tank 28, a delivery side of the fuel pump 35 is connected to the fuel supply passage 29, and a fuel filter 36 is attached to the suction side. Further, the exhaust passage 37 is provided with an O ₂ sensor 38 that generates an output based on the oxygen concentration in the exhaust gas. Further, a catalytic converter 39 is provided downstream of the O ₂ sensor 38 to form an exhaust system.

Further, the automatic transmission of the present example is, as shown in FIG. 2, a torque converter 50, a speed change gear mechanism 70 driven by the output of the converter, and a clutch, a brake, etc. for switching the power transmission path of the mechanism 70. It has a plurality of friction elements. By combining the operations of these friction elements, a desired gear stage or a stopped state in the range of D, 2, 1, R, P, N, etc. is established.

The torque converter 50 has an engine output shaft 5
Pump 53 provided in case 52 connected to 1
A turbine 54 disposed to face the pump 53, a stator 57 disposed between the turbine 54 and the pump 53, supported by the transmission case 55 via a one-way clutch 56, and performing a torque increasing action; The lockup clutch 58 is provided between the case 52 and the turbine 54, and directly connects the engine output shaft 51 and the turbine 54 via the case 52. The rotation of the turbine 54 is output to the speed change gear mechanism 70 side via the turbine shaft 59. Here, the turbine shaft 5 is attached to the engine output shaft 51.
A pump shaft 60 penetrating the inside of the transmission 9 is connected, and the shaft 12 drives an oil pump 61 provided at the rear end of the transmission.

On the other hand, the speed change gear mechanism 70 has a small diameter small sun gear 71 loosely fitted on the turbine shaft 59 and a large diameter small sun gear 71 rearwardly fitted on the turbine shaft 59. A large sun gear 72, a plurality of short pinion gears 73 meshed with the small sun gear 71, a front half of the long pinion gear 74 meshed with the short pinion gear 71, and a second half of the long pinion gear 74 meshed with the large sun gear 72; Pinion gear 74 and the short pinion gear 73
It is composed of a carrier 75 for rotatably supporting and a ring gear 76 meshed with the long pinion gear 74.

A forward clutch 77 and a first one-way clutch 78 are provided in series between the turbine shaft 59 and the small sun gear 71, and a coast clutch 79 is provided in parallel with these clutches 77, 78. A 3-4 clutch 80 is provided between the turbine shaft 59 and the carrier 75, and a reverse clutch 44 is provided between the turbine shaft 27 and the large sun gear 32. Further, between the large sun gear 72 and the reverse clutch 81, a 2-4 brake 82 which is a band brake for fixing the large sun gear 72 is provided. A second one-way clutch 83 that receives the reaction force of the carrier 75 and a low reverse brake 84 that fixes the carrier 75 are provided in parallel. The ring gear 76 is connected to the output gear 85, and the rotation is transmitted from the output gear 85 to the left and right wheels via the differential device. Here, the friction elements 77-84 such as the above clutches and brakes.
The relationship between the operating states of the one-way clutches 78 and 83 and the shift speed is summarized in FIG.

The engine 1 of this example preferably includes an electronic control unit 40 including a microcomputer. The control unit 40 is
The engine speed sensor attached to the distributor, the signal from the air flow meter 11, the throttle opening sensor 16, the water temperature sensor 41 for detecting the temperature of the cooling water in the water jacket of the engine, the O ₂ sensor 38, and the turbine speed are detected. Various control signals are output based on the detected signals from the turbine sensor 42 and the like. Further, it outputs a throttle valve opening signal and a fuel supply signal to the injector 22. Further, it outputs an ignition control signal to the ignition plug 43 via the ignition coil and the distributor. Also, a control signal is output to a solenoid valve that controls a hydraulic circuit of the automatic transmission to obtain a predetermined shift position.

Next, a basic idea of the relationship between the air-fuel ratio control and the shift control performed by the control unit 40 will be described with reference to the block chart of FIG. The control unit 40 of this example is configured to include the following components in terms of function. That is, it is defined by a zone determination unit 90 that determines to which operating zone (region) the current operating state of the vehicle belongs in terms of the air-fuel ratio from the engine speed and the accelerator opening, the accelerator opening, and the vehicle speed. A gear shift determination unit 91 that determines whether or not to perform a gear shift based on the operating state of the gear shift control line
It has and. The result from the zone determination unit 90 is from the lean zone (λ> 1) to the theoretical air-fuel ratio zone (λ = 1).
It is sent to the change determination unit 92 which determines whether or not the operating state should be shifted to. Further, the determination result from the shift determination unit 91 is sent to the lockup determination unit 93, and it is determined whether or not the lockup should be performed. Furthermore, the control unit 40 of this example is provided with a control determination unit 94.
The control determination unit 94 is an air-fuel ratio control unit 94a that performs control on the premise that the target air-fuel ratio is changed from the lean zone to the rich zone, and changes the target air-fuel ratio from the lean zone to the rich zone. The shift control unit 94 that prohibits and responds to the output request by the shift control (shift down)
b. Then, these control units 94a and 94b
The control signals are controlled so as to achieve the target air-fuel ratio and shift speed.

Referring to FIG. 5, the air-fuel ratio of this embodiment and the automatic
The control of the transmission will be described. First, control unit
The input unit 19 inputs various signals (step S1).
Among these, the engine speed N from the speed sensor,
And the intake air intake amount Qa from the air flow meter 11,
Cell opening, shift position in automatic transmission, vehicle speed, O ₂Sen
The status of the air-fuel ratio due to the output from the sensor is included. Next
In addition, the control unit 19 has an engine speed.
The operating conditions specified by the vehicle speed and engine load.
The air-fuel ratio is leaner than the stoichiometric air-fuel ratio.
To determine whether the vehicle is being driven (step S
2).

In this case, the control unit is shown in FIG.
It is equipped with a map created based on the relationship between the engine speed and the engine speed as shown in, and in light of this map, the air-fuel ratio operating zone is either the lean zone or the theoretical air-fuel ratio operating at the theoretical air-fuel ratio. It is determined whether it is a zone or an enriched zone operating on the rich side (smaller than the theoretical air-fuel ratio) side of the theoretical air-fuel ratio. In addition, PS1, PS
2 and PS3 are the same horsepower line. As can be seen from the figure, the same horsepower line extends over a region having different air-fuel ratios.

Regarding the shift position, the control unit 40 detects the shift position and the lockup state based on the shift map of the automatic transmission as shown in FIG. And the control unit 40
Determines whether the output request is increased by the accelerator operation (step S3).

In this case, the control unit 40 is
The value of the flag F1 is determined based on the result of executing the subroutine which is the interrupt routine of FIG. In the routine of FIG. 9, it is assumed that the control unit 40 achieves by shifting down the output request after the accelerator operation is performed, and based on the map of FIG. It is determined whether the number N0 is greater than the reference rotation speed N1. When the rotational speed is higher than the reference rotational speed N1, it is impossible to perform lean operation regardless of the engine load, so the control unit 40 sets the flag F1 indicating this to 1. If not, it is possible to set the operating state in the lean zone, so F1 is set to 0 to display that fact.

In the main routine, the value of the flag F1 set by the procedure of FIG. 8 is judged (step S4). Next, the control unit sends another flag F
The value of 2 is determined (step S5). This flag F2
Although the current operating state is in the lean zone, the pumping loss becomes larger than that when operating at λ = 1 (increase in rotational speed, intake negative pressure is large), so in reality it is lean to improve fuel efficiency. It is determined whether or not the driving effect cannot be expected, that is, in the region on the low load side of the line K in FIG.

This determination is made by executing a subroutine which is an interrupt routine to determine the flag F2, similarly to the determination of the flag F1. This procedure is shown by the flowchart of FIG. In FIG. 9, the control unit 40 controls the intake negative pressure P
Detect B0. Then, the reference negative pressure PB1 indicating the limit at which fuel consumption deteriorates is read and both are compared. Then, the intake negative pressure PB0
Is larger than the reference negative pressure PB1, it corresponds to a region below the line K in FIG. 6 where the pumping loss is large. In this case, the flag F2 is set to 1. On the other hand, if not so, the fuel consumption can be improved by lean driving, so the control unit 40 sets the flag F2 to 0.

In step S5, when the value of the flag F2 is 0, the control unit 40 then determines whether the state of the automatic transmission is the torque converter state, that is, whether the lockup state is not established ( Step S6). If not, the control unit 40 then determines whether the shift position of the automatic transmission is the fourth speed (step S).
7). In the case of the fourth speed, the control unit 40
Shifts down the shift position of the automatic transmission from the fourth speed to the third speed (step S8).

This operation will be described with reference to FIG. now,
It is assumed that the same shift position is maintained when the accelerator is operated in the operating state at the point A in the lean zone of FIG. 6, that is, in order to secure a desired output in the state where the fourth speed is maintained. Changes the operating state to point B in the stoichiometric air-fuel ratio zone. As a result, fuel efficiency deteriorates.
However, if downshifting is performed so that the same output is obtained in the third speed state, it is possible to stay at the point C in the lean zone. In this case, the control unit does not change the air-fuel ratio zone but changes the shift position.

As described above, in this example, when the acceleration operation is performed, it is first determined whether or not the air-fuel ratio zone is changed while the same shift position is maintained. If there is a change in the air-fuel ratio zone in this state, further downshifting is performed to determine whether the air-fuel ratio zone has been changed (S3 '). When there is no change in the air-fuel ratio zone as a result of this determination, the control unit commands the shift-down operation to be performed so as not to deteriorate fuel efficiency as much as possible.

Similar control is performed in the case of the third speed and the second speed (steps S9, S10, S11, S12).
In the case of the 1st speed, the downshift operation is impossible, so in this case, the control unit allows the air-fuel ratio zone to shift to the rich tendency (step S1).
3). When it is determined in steps S4, S5, and S6 that the lean operation condition is not satisfied, the control unit 40 allows the lean air-fuel ratio to be increased to the stoichiometric air-fuel ratio (step S14).

In the lockup state, when the request for changing the zone of the air-fuel ratio is made, the lockup is not released but the zone is changed for the following reason. Fuel efficiency deteriorates due to the transition from the lean zone to the stoichiometric air-fuel ratio zone or the enrichment zone. In order to compensate for this deterioration of fuel efficiency, it is possible to perform the torque amplification and secure the same output by not changing the zone and releasing the lockup state to the torque converter state. However, when the lockup state is released to the torque converter state, power transmission is performed via fluid, and energy loss occurs due to fluid resistance, resulting in deterioration of fuel efficiency.

When the deterioration of fuel efficiency due to the change of the air-fuel ratio zone and the deterioration of fuel efficiency due to the lockup cancellation are compared, the deterioration of the fuel efficiency due to the lockup cancellation has a larger effect. Is allowed and the lockup state is maintained. Note that this is not the case in the case of acceleration operation in which the desired output cannot be achieved simply by changing the air-fuel ratio.

Referring to FIG. 10, there is shown a procedure for detecting the zone on the lower load side than the line K using the means of the present invention. In this example, the accelerator opening T0 is detected instead of the intake negative pressure, and the zone is determined by comparing it with the reference value T1. Then, the value of the flag F3 is determined. This flag F3 is used instead of the above flag F2.

[0046]

According to the present invention, the engine is operated so that the air-fuel ratio is on the lean side as much as possible, and the output of the automatic transmission is changed to secure the output, so that the fuel consumption can be improved. In addition, the desired output performance can be secured. Further, in the lockup state, the change in the air-fuel ratio is allowed and the state in which the energy loss is small is maintained, so that the deterioration of fuel consumption can be suppressed.

Further, in a region where lean operation is practically impossible, the limit is set to allow the change of the air-fuel ratio, so that when the air-fuel ratio and the automatic transmission are comprehensively controlled, There are no other obstacles.

[Brief description of drawings]

FIG. 1 is a schematic configuration of an engine equipped with an air-fuel ratio control device according to an embodiment of the present invention,

FIG. 2 is a schematic view of a transmission mechanism of an automatic transmission,

FIG. 3 is a diagram showing a relationship between an operation of a friction element of an automatic transmission and a shift position,

FIG. 4 is a block diagram of a control unit according to an embodiment of the present invention,

FIG. 5 is a flowchart of control of an engine air-fuel ratio and an automatic transmission according to the present invention,

FIG. 6 is a graph showing the relationship between the throttle opening, the engine speed, and the air-fuel ratio zone,

FIG. 7 is a shift control map of the automatic transmission,

FIG. 8 is a flowchart showing a procedure for defining a lean zone based on the engine speed,

FIG. 9 is a flowchart showing a procedure for determining a lean zone based on an intake negative pressure,

FIG. 10 is a flowchart showing a procedure for determining a lean zone based on an accelerator opening.

[Explanation of symbols]

1 engine, 3 pistons, 11 intake passages, 12
Air flow meter, 16 throttle valve, 38 O ₂
Sensor, 40 control unit, 50 torque converter, 70 speed change gear mechanism.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location F02D 41/14 310 P 8011-3G (72) Inventor Hiroshi Takagi Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture No. 1 in Mazda Motor Corporation

Claims (7)

[Claims] 1. An engine, an automatic transmission coupled to the engine, an air-fuel ratio detecting means for detecting an air-fuel ratio of fuel supplied to the engine, and an air-fuel ratio for setting an air-fuel ratio corresponding to an operating region of the engine. Setting means, and air-fuel ratio control means for controlling the air-fuel ratio of the fuel to be supplied to the air-fuel ratio to reach a predetermined value so as to achieve the target air-fuel ratio set by the air-fuel ratio setting means according to the operating state, and the operating state Change means for performing a shift operation in the automatic transmission in response to the change of the target value, a determining means for determining whether or not a change in the target air-fuel ratio occurs based on a change in the operating region due to a change in the operating state, and the target by the determining means. When it is determined that a change in the air-fuel ratio will occur, an air-fuel ratio change inhibiting means for inhibiting the change in the target air-fuel ratio, and a signal for inhibiting the change in the target air-fuel ratio by the air-fuel ratio change inhibiting means Rutoki, the general control unit of an engine and an automatic transmission, characterized in that a control means for maintaining the same work rate without changing the target air-fuel ratio and outputs a speed command to the speed change means. 2. The change of the operating range according to claim 1, wherein the target air-fuel ratio is set to a leaner range than the stoichiometric air-fuel ratio to a stoichiometric air-fuel ratio range where the target air-fuel ratio is set to the stoichiometric air-fuel ratio. Comprehensive control device for engine and automatic transmission characterized by being changed. 3. The engine according to claim 1 or 2, wherein when the automatic transmission is in a lockup state, the operation of the air-fuel ratio change prohibiting means is stopped to allow the change of the target air-fuel ratio. Integrated control system for automatic transmission. 4. The air-fuel ratio change prohibition according to claim 1 or 2, when the operating region after the gear shifting operation is predicted and the operating state realized in the operating region does not satisfy a predetermined condition. An integrated control device for an engine and an automatic transmission, characterized in that the operation of the means is stopped and the change of the air-fuel ratio is allowed. 5. A fuel consumption detecting means for detecting fuel consumption according to claim 1 or 2, further comprising a fuel consumption detecting means for comparing a fuel consumption after a change of an operating range and a fuel consumption after a gear shift operation, and changing a target air-fuel ratio based on the result. Alternatively, an integrated control device for an engine and an automatic transmission, characterized by performing either a gear shift operation. 6. An integrated control system for an engine and an automatic transmission according to claim 5, wherein the fuel consumption detection means detects an intake negative pressure. 7. An integrated control system for an engine and an automatic transmission according to claim 5, wherein the fuel consumption detecting means detects an accelerator opening degree.