JP2795087B2 - Integrated control device for engine and automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general control system for an engine and an automatic transmission of a vehicle equipped with both an engine and an automatic transmission capable of changing the air-fuel ratio to the lean side.

[0002]

2. Description of the Related Art In recent years, the reduction of fuel consumption of an automobile engine has become a major technical problem, and lean burn control of the engine is known as one means of achieving the reduction of fuel consumption. This is the vehicle operating conditions, specifically the vehicle speed,
Only when the conditions such as the gear position of the transmission, the engine coolant temperature, the throttle opening and the like are within a predetermined lean region, the target air-fuel ratio of the air-fuel ratio control is not the stoichiometric air-fuel ratio, but the leaner side. The air-fuel ratio is set to perform lean combustion.

Further, in a vehicle equipped with an engine that performs such lean burn control and an automatic transmission, the engine torque fluctuation caused by the lean burn control does not adversely affect the control of the automatic transmission. A control device described in JP-A-64-45933 is known.

In this conventional device, lockup control of the automatic transmission is prioritized over lean burn control of the engine. That is, during lockup control of the automatic transmission, even if the operating conditions of the vehicle are in the lean region, Target air-fuel ratio
The correction is made to a value smaller than the normal lean air-fuel ratio or to a value close to the stoichiometric air-fuel ratio. As a result, the engine does not become extremely unstable, and it is possible to avoid deterioration of the riding comfort and drivability of the vehicle.

[0005]

However, in the above-mentioned conventional integrated control device for an engine and an automatic transmission,
Since the change of the air-fuel ratio of the lean / stoichiometric air-fuel ratio of the engine and the change of the gear position of the automatic transmission are performed independently by separate controllers, there are the following problems.

(1) For example, when changing from the stoichiometric air-fuel ratio side to the lean side, a decrease in the engine torque causes a decrease in the output torque, and as a result, an operation such as increasing the throttle is required. However, when such an operation of increasing the throttle is performed, a downshift of the automatic transmission is induced, and as a result, control for changing from the lean side to the stoichiometric air-fuel ratio may be performed. In such a case, hunting of the shift speed and output torque occurs, and the drivability is significantly impaired.

(2) In the case of control by an independent controller, the engine control side prepares a map in which a lean region and a stoichiometric air-fuel ratio region are set according to the engine speed and the throttle opening, and the automatic transmission control side controls the vehicle speed. By preparing a map in which the shift speed region is set according to the throttle opening and the throttle opening, the regions are determined independently of each other, which leads to an increase in the memory capacity of the controller and an increase in the determination process, which is disadvantageous in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in consideration of the above-described problems. An engine for a vehicle having both an engine capable of changing the air-fuel ratio to the lean side and an automatic transmission, and an automatic transmission It is an object of the present invention to provide an integrated control device that improves the drivability by preventing the occurrence of hunting of the shift speed and the output torque while providing a control system that is advantageous in terms of cost.

[0009]

In order to solve the above-mentioned problems, in the engine and automatic transmission integrated control device of the present invention, a shift / air / fuel ratio boundary line also serving as a shift boundary line and one shift stage region are adjacent to each other. A map setting means that presets a common map in which air-fuel ratio boundaries dividing the stoichiometric air-fuel ratio area and the lean area are alternately arranged according to the driving state of the vehicle, and common to the input from the driving state detection means A region determining means for determining a lean, stoichiometric air-fuel ratio region of the engine and a gear position region of the automatic transmission based on the map is provided.

That is, as shown in the claim correspondence diagram of FIG. 1, an air-fuel ratio actuator a capable of changing the air-fuel ratio of the engine to a lean side or a stoichiometric air-fuel ratio side, and a speed change gear for switching a gear position of an automatic transmission. An actuator b, an operating state detecting means c for detecting an operating state of the vehicle, an air / fuel ratio boundary line also serving as a shift boundary line, and an air for dividing one shift speed region into an adjacent stoichiometric air / fuel ratio region and a lean region. Map setting means d which presets a common map in which fuel ratio boundary lines are alternately arranged according to the driving state of the vehicle,
The area determination means e for determining the engine lean, the stoichiometric air-fuel ratio area and the gear position area of the automatic transmission based on the input from the operating state detection means c and the common map, and the area determination means e An air-fuel ratio control command means f for outputting a command for setting a lean or stoichiometric air-fuel ratio to the air-fuel ratio actuator a, and a command for obtaining the shift speed determined by the area determining means e are output to the shift actuator b. And a shift control instructing means g.

The operating state detecting means c is means for detecting at least the vehicle speed and the throttle opening, and the map setting means d is a high vehicle speed / low throttle opening based on the vehicle speed and the throttle opening. It is also possible to use a means that sets a common map in which the higher the speed, the closer the lean side.

[0012]

When the vehicle is running, in the area determining means e, based on the input from the operating state detecting means c, based on the map set in the map setting means d, the engine lean, the stoichiometric air-fuel ratio and the speed of the automatic transmission are changed. A step region is determined.

Then, in the air-fuel ratio control command means f,
A command to set the air-fuel ratio to the lean or stoichiometric air-fuel ratio determined by the area determining means e is output to the air-fuel ratio actuator a. Further, a command for obtaining the shift speed determined by the region determining means e in the shift control command means g is output to the shift actuator b.

Therefore, the control is performed using the common map for the air-fuel ratio control and the shift control, and
This common map corresponds to the operating state of the vehicle by combining a shift-use air-fuel ratio boundary line also serving as a shift boundary line and an air-fuel ratio boundary line dividing one shift speed region into an adjacent stoichiometric air-fuel ratio region and a lean region. By arranging them alternately, hunting of the shift speed and the output torque is suppressed, and good operability is secured.

For example, when the vehicle is changed from the lean side to the stoichiometric air-fuel ratio side by increasing the vehicle speed or depressing the accelerator pedal, etc., and the air-fuel ratio boundary line traversing at that time is the shift / air-fuel ratio boundary line, the theoretical The change to the air-fuel ratio and the upshift are performed simultaneously, and the increase in the output torque caused by setting the air-fuel ratio of the engine to the stoichiometric air-fuel ratio is suppressed by the upshift, and it is necessary to increase the accelerator return that causes hunting. Not.

If the stoichiometric air-fuel ratio is changed from the stoichiometric side to the lean side by a decrease in the vehicle speed or the accelerator pedal is depressed, etc., and the air-fuel ratio boundary line traversing at that time is a shift / air-fuel ratio boundary line, the engine goes to the lean state. And the downshift are performed at the same time, and the decrease in output torque due to the leaner air-fuel ratio of the engine is compensated for by the downshift, and there is no need to increase the accelerator pedal which causes hunting.

Further, when the vehicle crosses the air-fuel ratio boundary line, which is divided into the stoichiometric air-fuel ratio region and the lean region, by increasing the vehicle speed or depressing the accelerator at each gear, the stoichiometric air-fuel ratio side is changed to the lean side. However, the output torque is reduced, but this corresponds to the increase in the vehicle speed and the operation of returning the accelerator pedal, and does not give a sense of incongruity in the driving performance.

At each gear, when the vehicle crosses an air-fuel ratio boundary line which is divided into a stoichiometric air-fuel ratio region and a lean region due to a decrease in vehicle speed or an accelerator pedal depression operation, the lean-to-stoichiometric air-fuel ratio side is changed. Although the output torque increases, this corresponds to a decrease in the vehicle speed or an operation of depressing the accelerator, and does not give a sense of incongruity to the drivability.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

The configuration will be described.

FIG. 2 is an overall control system diagram to which the integrated control device for the engine and the automatic transmission according to the embodiment of the present invention is applied.

In FIG. 1, E denotes an engine, which is provided with an injector 1 (corresponding to an air-fuel ratio actuator) for injecting fuel and a spark plug 2 for igniting the fuel. Note that the injector 1 can adjust the air-fuel ratio by arbitrarily changing the fuel injection amount.

In the figure, AT is an automatic transmission,
The shift speed is switched by control of the hydraulic pressure by the control valve CV, and the valve in the control valve CV is operated to switch the shift speed, reduce the shift shock, and reduce the torque converter torque.
A line pressure solenoid 3a, a lock-up solenoid 3b, an overrun clutch solenoid 3c, shift solenoids 3d and 3e (corresponding to a shift actuator) are provided for switching between lock-up and non-lock-up of C.

The driving of the injector 1, the ignition plug 2 and the solenoids 3a to 3e is controlled by a general control unit 4. That is, the overall control unit 4 includes an O ₂ sensor 5a, a throttle sensor 5b (corresponding to an operation state detecting means), a knock sensor 5
c, water temperature sensor 5d, engine rotation sensor 5e, inhibitor switch 5f, oil temperature sensor 5g, vehicle speed sensor 5h
A signal is input from a group of sensors 5 (corresponding to operating state detecting means) to control the ignition timing and the air-fuel ratio of the engine E, as well as to change the gear position of the automatic transmission AT, change the switching timing, and reduce the shift shock. The engine control unit (air-fuel ratio control command unit) 4a, the AT control unit (shift control command unit) 4b, the area determination unit (area determination unit) 4c, and the map setting unit (map setting unit) 4d perform control and the like. Have.

The engine control section 4a is a section for controlling the driving of the injector 1 and the spark plug 2 in order to control the ignition timing and the air-fuel ratio of the engine E. Also, A
The T control unit 4b controls each of the solenoids 3a to 3
This is a part for controlling the driving of 3e.

Among the controls performed by the engine control unit 4a and the AT control unit 4b, the control relating to the air-fuel ratio and the shift speed are both performed based on the determination of the region determination unit 4c. That is, the area determination unit 4c is provided with the vehicle speed sensor 5h.
Is a part that determines both the air-fuel ratio region of the engine E and the gear position region of the automatic transmission AT according to the vehicle speed VSP obtained from the vehicle speed V and the throttle opening TVO obtained from the throttle sensor 5b. This is performed based on the common map stored in the map setting unit 4d.

Here, the common map stored in the map setting section 4d will be described. As shown in FIG. 3, this common map switches between the vehicle speed (horizontal axis) VSP and the throttle opening (vertical axis) TVO. As the elements, the lean-side, the stoichiometric air-fuel ratio side, and the first-fourth to fourth-speed air-fuel ratio / gear speed regions are preset, and S in the figure represents the stoichiometric air-fuel ratio region.
Indicates a lean region, and numerals 1 to 4 at the lower right of S and L indicate shift speeds. As shown in the figure, the higher the vehicle speed and the lower the throttle opening, the leaner and the higher the speed. It is set as follows. In the drawing, (A) shows a common map for upshift, and (B) shows a common map for downshift. As shown in the figure, at the first speed, which is the low gear, there is no lean side, and there is no L1 region. In the kickdown region, only the stoichiometric air-fuel ratio region is set, and in the low throttle opening region, only the lean region except for the first speed is set.

Next, the air-fuel ratio / shift control operation will be described.

FIG. 4 is a flowchart showing a main routine of the flow of the air-fuel ratio / shift control operation performed by the integrated control unit 4.

In step 101, the throttle sensor 5
b and the throttle opening detected by the vehicle speed sensor 5h
TVO and vehicle speed VSP are read.

In step 102, the common map stored in the map setting section 4d is searched by the area determination section 4c, and based on the throttle opening TVO and the vehicle speed VSP, any one of the lean and stoichiometric air-fuel ratio ranges is determined. It is determined whether the vehicle is in the gear position and in what speed position it is.

In step 103, based on the determination by the area determination section 4c, a process is performed in which the injector 1 is driven by the engine control section 4a to switch the air-fuel ratio to the lean side or the stoichiometric air-fuel ratio side.

In step 104, the AT control section 4b drives the shift solenoids 3d and 3e based on the setting of the area determination section 4c to switch the automatic transmission AT to a predetermined gear.

The flowchart shown in FIG. 5 shows a subroutine for the common map search processing shown in step 102.

In step 201, the current state (air-fuel ratio / gear speed range) is read by replacing it with an integer n. This current state n is as shown in the control table of Table 1 below.

In step 202, the detected throttle opening TVO is partitioned into a state n + 1 on the right of the current state n (for example, Ln or Sn + 1 when the area is Sn or Ln in the current common map). Boundary line f
It is determined whether or not _{n / n + 1} (VSP) or less. Step 2
If YES in 02, the process proceeds to step 203, and if NO in step 202, the process proceeds to step 204.

In step 203, the current state n is n + 1
Is rewritten as

In step 204, if the detected throttle opening TVO is the state n-1 on the left of the current state n (for example, if it is the current Sn or Ln area, Ln-
1 or Sn) is determined to be greater than or _equal to a boundary line f _{n / n-1} (VSP).

In step 205, the current state n is n-1
Is rewritten as

[0040]

[Table 1] Next, a control operation during traveling will be described.

At the time of traveling, the area determination section 4c reads the throttle opening TVO and the vehicle speed VSP detected by the throttle sensor 5b and the vehicle speed sensor 5h, and based on these, the common map stored in the map setting section 4d. Is searched in accordance with the processing shown in FIG. 5 to determine the air-fuel ratio / gear ratio region.

That is, if the throttle opening TVO is equal to or smaller than the boundary line f _{n / n + 1} (VSP) that separates the currently controlled state n from the state n + 1 on the right in FIG. Set to the next state n + 1 (for example, if the current state is S3, L3
Conversely, if the throttle opening TVO is greater than or equal to the boundary line f _{n / n-1} (VSP) that separates the currently controlled state n from the state n-1 on the left. , State n-1 on the left
(For example, if it is the current S3, it is set to L2), otherwise, it is set to maintain the current state n.

As described above, the area determination unit 4c performs the area determination using only one common map, and the common map is used as the shift / air / fuel ratio boundary line (L2-S3 boundary line) which also serves as the shift boundary line. , L3-S4 boundary line) and an air-fuel ratio boundary line (S2-L2 boundary line, S3-L3) dividing one shift speed region into an adjacent stoichiometric air-fuel ratio region and a lean region.
Boundary line, S4-L4 boundary line) are alternately arranged corresponding to the vehicle speed VSP and the throttle opening TVO.
Hunting of the shift speed and output torque is suppressed, and good operability is ensured.

A specific example will be described below.

For example, in FIG. 3A, the throttle opening TVO associated with the increase in the vehicle speed VSP and the operation of depressing the accelerator pedal is shown.
When the air-fuel ratio is changed from the lean side to the stoichiometric air-fuel ratio side due to a decrease in the air-fuel ratio, and the air-fuel ratio boundary line crossing at that time is L2-S3
When the vehicle is on the boundary line, the change from lean L to the stoichiometric air-fuel ratio S and the 2 → 3 upshift are performed simultaneously, and the increase in the output torque caused by setting the air-fuel ratio of the engine E to the stoichiometric air-fuel ratio is 2 → 3. Suppressed by upshifting, there is no need to increase the accelerator return operation.

For example, in FIG. 3B, the throttle opening TVO associated with the decrease in the vehicle speed VSP and the accelerator depression operation is shown.
When the air-fuel ratio is changed from the stoichiometric air-fuel ratio side to the lean side due to an increase in the air-fuel ratio, the air-fuel ratio boundary line that crosses at that time is S3-L2
At the boundary line, the change from the stoichiometric air-fuel ratio S to the lean L and the 3 → 2 downshift are performed simultaneously, and the decrease in the output torque due to the leaning of the engine E air-fuel ratio reduces the 3 → 2 downshift. Supplemented by gear shifting, there is no need for additional accelerator operation.

For example, in FIG. 3A, at the third speed position, the S3-L3 boundary is divided into a stoichiometric air-fuel ratio region and a lean region by increasing the vehicle speed VSP or decreasing the throttle opening TVO due to the accelerator depressing operation. When the vehicle crosses the line, the stoichiometric air-fuel ratio is changed to the lean side, and the output torque decreases.However, this corresponds to the increase in vehicle speed and the accelerator step-back operation. Air-fuel ratio control with a reduction effect and an exhaust gas reduction effect is ensured.

For example, in FIG. 3B, at the third speed position, the S3-L3 boundary line is divided into a stoichiometric air-fuel ratio region and a lean region by a decrease in the vehicle speed VSP or an increase in the throttle opening TVO due to an accelerator depression operation. When the vehicle crosses, the output torque increases from the lean side to the stoichiometric air-fuel ratio, and this corresponds to the decrease in vehicle speed and the accelerator pedal depression operation. Is secured.

Next, the effects will be described.

(1) In an integrated control system for an engine and an automatic transmission of a vehicle equipped with both an engine E capable of changing the air-fuel ratio to the lean side and an automatic transmission AT, a shift / shift air which also serves as a shift boundary line. A common map in which the fuel ratio boundary line and the air-fuel ratio boundary line dividing one shift speed region into the adjacent stoichiometric air-fuel ratio region and lean region are alternately arranged corresponding to the vehicle speed VSP and the throttle opening TVO is set in advance. And a system for determining the leanness of the engine E, the stoichiometric air-fuel ratio region and the gear position region of the automatic transmission AT based on the input of the vehicle speed VSP and the throttle opening TVO and the common map. In addition, it is possible to prevent hunting of the shift speed and the output torque, thereby improving drivability.

(2) Since the driving state of the vehicle used in the common map is the vehicle speed VSP and the throttle opening TVO, the vehicle speed VSP
A common map can be easily created by using the shift map set by the throttle opening TVO and the lean area and the stoichiometric air-fuel ratio area.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to this embodiment.

In the embodiment, the example in which the vehicle speed sensor and the throttle sensor are used as the driving state detecting means has been described.
It is only necessary to be able to detect the operating state necessary for setting the optimum air-fuel ratio and the optimum gear position. Therefore, another sensor such as an engine speed sensor or a torque sensor may be used.

[0054]

As described above, according to the present invention, comprehensive control of an engine and an automatic transmission of a vehicle having both an engine capable of changing the air-fuel ratio to the lean side and an automatic transmission is provided. In the device, a shift / combination air-fuel ratio boundary line also serving as a shift boundary line and an air-fuel ratio boundary line dividing one shift speed region into an adjacent stoichiometric air-fuel ratio region and a lean region are alternately provided in accordance with the driving state of the vehicle. Map setting means for presetting the arranged common map, and area judging means for judging a lean, stoichiometric air-fuel ratio area of the engine and a gear position area of the automatic transmission based on the input from the operating state detecting means and the common map. Thus, it is possible to improve the drivability by preventing the occurrence of hunting of the shift speed and the output torque while providing a control system that is advantageous in terms of cost. That.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing an integrated control device for an engine and an automatic transmission according to the present invention.

FIG. 2 is an overall system diagram to which the integrated control device for the engine and the automatic transmission according to the embodiment is applied.

FIG. 3 is a diagram illustrating a common map stored and set in a map setting unit of the apparatus according to the embodiment.

FIG. 4 is a flowchart showing a flow of a main routine of engine control and shift control performed by a general control unit of the embodiment device.

FIG. 5 is a flowchart illustrating a flow of an operation of a common map search performed by the integrated control unit of the embodiment device.

[Explanation of symbols]

 a air-fuel ratio actuator b shift actuator c operating state detecting means d map setting means e area determining means f air-fuel ratio control command means g shift control command means

Claims (2)

(57) [Claims] 1. An air-fuel ratio actuator capable of changing an air-fuel ratio of an engine to a lean side or a stoichiometric air-fuel ratio side, a shift actuator for switching a gear position of an automatic transmission, and an operating state for detecting an operating state of a vehicle. A detecting means, a shift-use air-fuel ratio boundary line also serving as a shift boundary line, and an air-fuel ratio boundary line dividing one shift speed region into an adjacent stoichiometric air-fuel ratio region and a lean region, alternately corresponding to the operating state of the vehicle. Map setting means for presetting a common map arranged in the vehicle, and determining a lean, stoichiometric air-fuel ratio region and a gear position region of the automatic transmission based on an input from the operating state detecting means and the common map. Area determination means, and air-fuel ratio control instruction means for outputting a command to the lean or stoichiometric air-fuel ratio determined by the area determination means to the air-fuel ratio actuator; The general control unit of an engine and an automatic transmission, characterized in that and a transmission control command means for outputting a command to obtain the gear position determined by said area determining means, to the shift actuator. 2. The driving state detecting means is means for detecting at least a vehicle speed and a throttle opening, and the map setting means is a high vehicle speed / low throttle opening based on the vehicle speed and the throttle opening. 2. The integrated control device for an engine and an automatic transmission according to claim 1, wherein the common map is set such that the higher the speed, the closer to the lean side.