JPS5958251A - Control method for internal combustion engine and automatic speed change gear - Google Patents

Abstract

PURPOSE:To realize control of the automatic speed-change gear ratio to the speed of an engine so as to always set the smallest fuel consumption in response to an operational condition by determining the target number of rotations and displayed target average effective pressure not only for fulfilling required output but also satisfying axial torque which is most appropriate to fuel consumption or output. CONSTITUTION:Required output Po is determined according to opening of an accelerator, and target number of rotations and displayed target average effective pressure Pi, not only for fulfilling required output Po on the basis of a data map previously housed in a control circuit but also satisfying axial torque which is most appropriate to fuel consumption or output, are determined and the gear ratio of an automatic speed change gear and opening of a throttle are controlled so that said target engine speed and displayed target average effective pressure are maintained by an engine. Thus, the automatic speed change gear ratio to the speed of the engine can be controlled so as to set the smallest fuel consmption in response to an operational condition at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for controlling an internal combustion engine and an automatic transmission, and in particular a method for controlling an internal combustion engine and an automatic transmission. The present invention relates to an internal combustion engine and an automatic transmission control method for controlling the engine speed and the gear ratio of the automatic transmission so as to achieve a higher fuel efficiency rate without reducing fuel consumption.

Conventionally, automatic transmissions calculate the output and fuel efficiency in the current driving state, assume the fuel efficiency when changing the current transmission gear ratio while maintaining the current vehicle speed, and calculate the estimated fuel efficiency in the current driving state. If the fuel consumption rate is better than the fuel consumption rate, the method used is to change the gear/V ratio.

However, although this method relatively improves the fuel efficiency when driving at a constant speed, there is no margin for engine output, so the vehicle speed will change due to a slight change in load. Controlling the speed change gear ratio in response to the accelerator operation, i.e., the amount of accelerator depression and the accelerator depression speed, was a national expense.

The present invention provides an internal combustion engine (knee 2) that overcomes the above-mentioned problems.
- The purpose of this invention is to provide a method for controlling automatic transmissions (engines) and automatic transmissions.

This purpose is to provide a combustion pressure sensor for a cylinder of the engine in an internal combustion engine of a vehicle equipped with an automatic transmission, a crank angle sensor that detects the crank position by rotating the crankshaft, and an accelerator. An accelerator sensor that detects the opening, a vehicle speed sensor, and each of the above sensors
Based on the control circuit that controls the engine and automatic transmission, calculates the required output according to 188 of the accelerator sensor, and satisfies the required output by 1 - both of which are optimal in terms of fuel efficiency or output. The target engine speed and the target indicated mean effective pressure of the combustion pressure that satisfy the axis 1 to torque are determined in advance based on the data map stored in the control circuit, and the engine is controlled to the target speed and the target indicated mean effective pressure. This is achieved by a method for controlling an internal combustion engine and an automatic transmission, which is characterized by controlling the transmission gear ratio and throttle distance of the automatic transmission so that the automatic transmission is operated at the same speed.

The present invention will be explained below by giving an example and referring to the drawings.

-3- First, Fig. 1 is a schematic diagram showing an outline of an engine, an automatic transmission, and the surroundings thereof] 72 of an embodiment to which the non-inventive method is applied.

In the same figure, 1 is a four-stroke, four-cylinder engine, L engine, 2
is a rotating disk that rotates in synchronization with the rotation of the crankshaft and has a magnet arranged around its circumference, 3 tJ, which is picked up by the rotation of the rotating disk 2; 4 is a crank angle sensor that detects a re-crank angle signal; A combustion pressure sensor 5 is integrated with a spark plug in each cylinder of the engine and detects the pressure inside the cylinder combustion chamber; 5 is an amplifier with high input impedance that amplifies the signals of the crank angle sensor 3 and the combustion pressure sensor 4; 6 is a P1 meter that displays the indicated average effective ITPi of each cylinder in synchronization with the signal from the crank angle sensor 3;
8 is a control circuit, 8 is a transmission mechanism drive circuit that drives a shift solenoid (not shown) of automatic transmission 9, 10 is a throttle actuator 1-driver circuit that drives throttle actuator 11, and 12 is a circuit that responds to the amount of accelerator depression. 13 is a shift positive sensor that detects the position of the shift lever, 14 is a medium speed sensor, and 15 is an engine water temperature sensor.

As shown in FIG. 2, the control circuit 7 includes two input ports 1 to 20121, an output port 22, and an input/output data processing unit 1! l! , a CPU (sensor 1 heral processing unit) 23 that controls the transmission mechanism drive circuit 8 and the throttle drive circuit 10, a ROM (read only memory) 24 that stores control programs and control data, input/output data, etc. It is composed of a RAM (random access memory) 25 that temporarily stores data.

Also stored in the ROM 24 are control programs as shown in FIG. 3 and data maps corresponding to the diagrams shown in FIGS. 4 to 6.

In this embodiment configured in this way, the engine rotation speed Neo with a moderate output margin is set based on the signals from various sensors including the crank angle sensor 3 and the combustion pressure sensor 4. The indicated mean effective pressure PiO is determined as a target value, and the transmission gear ratio and throttle opening degree = 5 - necessary to maintain the target value are controlled.

The operation of this embodiment will be explained in detail below along with the control block diagram of FIG. 3 and FIGS. 4 to 7.

The engine 1 is started, the shift lever f1 is operated, the shift lever f1 is set to the drive mode, and the processing of this program is started.

First, in step 30, according to the data map as shown in FIG. In this case, request output: lPO+ is selected.

Then, in the next step 31, the current accelerator depression operation is calculated from a function showing the correlation between the torque margin α and the accelerator opening degree θ, as shown in FIG. 7, and the correlation between the torque margin α and the accelerator depression speed dO/dt. Therefore, if the 1-lux margin required for driving, that is, the accelerator opening θ1, then α1'
+α1″ is set to 1 to silk tolerance α1.

Here, the torque margin indicates how much margin -6- there is before reaching the maximum shaft torque of the engine as shown in FIG. Therefore, 1-lux margin α
The shaft torque having , becomes a curve indicated by leo in the same figure.

In the following step 32, the shaft torque Te and the engine speed Ne are determined as shown in FIG.

A data map determined corresponding to a diagram showing the correlation between fuel consumption rate and output P, and engine rotation speed N as shown in Fig. 6.
o, axes 1 to l, and d, which are determined in accordance with a diagram representing the correlation between the indicated mean effective pressure Pi.

(Details) If it is correct, the point with the lowest fuel efficiency relative to the engine rotation speed, indicated by the dotted line J in Figure 5, is Pron 1-L,
The connected curve represents the shaft torque with the lowest fuel efficiency. Therefore, it is preferable to control the engine 1 along this curve in terms of fuel efficiency, and among the points on the curve showing the minimum fuel efficiency shaft torque in the figure, the points that satisfy the required output po,
In other words, since the relationship is as follows: output P (ps) = -7 - rotational speed Ne (rpm), Te
-(Pox layer 716.2)/Ne The engine rotational speed Ne and indicated mean effective pressure Pi corresponding to the intersection point X with the equal output curve are set as target values for control. However, although constant speed running t, r ``jj''``r'' on flat ground may have such target values, due to the characteristics of the engine 1, operating the engine near the maximum shaft torque may result in insufficient leeway for driving. The vehicle speed may change due to zero load fluctuations.

Therefore, in this embodiment, a curve parallel to the maximum shaft torque is drawn at intervals of the torque margin α calculated by the smooth tube 31, and the shaft torque TeO is maintained on this curve.
Then, the required output po is iM 1' , t: target indicated mean effective pressure Pio and target engine rotation speed NeO are calculated.

That is, in this step 32, first, the target engine speed Neo and the torque Te on the curve are determined from the intersection Y of the equal output curve indicating the required output PO and the curve indicating the shaft torque Tea.
The value of O is determined.

This value and the data corresponding to the diagram shown in Figure 6 =
8 - A target indicated mean effective pressure PiO is selected based on the map.

Then, in the next step 33, the current vehicle speed output from the vehicle speed sensor 14, the current engine rotation speed Ne detected based on the signal from the crank angle sensor 3, and the accelerator sensor 12.
The accelerator depression speed dθ/(It) calculated in step 31 based on the signal from
A transmission gear ratio that maintains eO is selected, and the solenoid of the automatic transmission 9 is driven via the transmission mechanism drive circuit 8 based on this gear ratio, and the throttle actuator 11 is controlled to maintain the target indicated mean effective pressure P10. Then, the process moves to the next step 34. When driving the solenoid of the automatic transmission 9 or controlling the throttle actuator 11, if the difference between the current output and the required output is small, the target engine speed Ne01 target indicated mean effective pressure Pi
It is possible to control the gear ratio and throttle opening so that the target indicated mean effective pressure Pio 4 or the target indicated mean effective pressure Pi
The vehicle speed is controlled by controlling Throat 1 to Throat 11 so that the current transmission gear ratio becomes O, and by selecting the transmission gear ratio from the current transmission gear ratio or a transmission gear to 7 ratio that is not significantly different from it, and changing the vehicle speed. Then, perform the same process as °C for this step next time, and also change the accelerator depression speed d.
When θ/dt is large, especially rapid acceleration is required, so the engine speed is set to the target engine speed and the target indicated mean effective pressure in a short time, ignoring the equal output curve and the curve showing the shaft torque Tea. The transmission gear 17 ratio is selected and the throttle actuator 11 is controlled.

In step 34, the current output P of the engine 1 is calculated from the indicated mean effective pressure Pi of each cylinder after the throttle opening degree has been controlled by the torque actuator 11 in the step described above, and the current engine rotation speed. and the requested output PO
If ``rpmpO'' is compared with ``rpmpO'', the processing of this program is terminated as it is assumed that the control is being performed as per the target, and ``rpmpO'' is
PSPO"-10-, the process of step 33 is performed again, and the above-described process is repeated.

As a result of the above control, the engine 1 is operated at the output requested by the driver, that is, the output PO according to the accelerator opening degree O, and the axis 1 to the torque TeO are accelerated. It is controlled with sufficient margin depending on the driving condition, vehicle speed, and load condition, and the transmission gear is also controlled according to these driving conditions and shift 1.
~Position on the R road shift 1~Position on the R road.

The above-mentioned automatic transmission may be equipped with either a multi-stage gear or a continuously variable gear. In addition, as the control target value, a value corresponding to the shaft torque that provides the minimum fuel consumption rate or the shaft torque that has a torque margin may be automatically or manually selected as appropriate depending on the driving condition. good.

As explained above, the internal combustion engine and automatic transmission control method of the present invention determines the required output according to the accelerator opening,
Based on a data map stored in the control circuit in advance, a target rotation speed and target indicated mean effective pressure are determined that satisfy the required output and satisfy the fuel consumption rate or the optimum shaft torque for the output. , the gear ratio and throttle opening of the automatic transmission are controlled so that the engine maintains the target engine speed and target indicated mean effective pressure.

Therefore, according to the present invention, it is possible to control the gear ratio of the engine and automatic transmission so as to always achieve the minimum fuel consumption according to the operating condition, and also to control the gear ratio of the engine and automatic transmission so as to always achieve the minimum fuel consumption, and when necessary, such as during acceleration, high speed rotation, or high load. Accordingly, by providing a control 61I that maintains the shaft torque with a certain degree of margin relative to the maximum engine torque, it becomes possible to suppress fluctuations in vehicle speed due to load fluctuations and the like, thereby ensuring drivability.

Since the engine shaft 1 herk is calculated exclusively from the indicated mean effective pressure of each cylinder, it is possible to perform control with good precision and responsiveness.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an outline of an engine, an automatic transmission, and its peripheral equipment according to a different embodiment of the present invention, FIG. 2 is a circuit diagram mainly showing the control circuit, and FIG. The figure is a diagram showing the control program that is the main part of this embodiment, Figures 4 and 6 are explanatory diagrams corresponding to the data map stored in the control circuit, and Figure 7 is a diagram showing the torque margin and accelerator. FIG. 2 is an explanatory diagram showing the correlation between engine speed, torque margin, and accelerator depression speed. 1... Engine 3... Crank angle sensor 4... Combustion pressure sensor 5... Amplifier 6... Pi meter 7... Control circuit 8... Transmission mechanism drive circuit 9... Automatic gear shift Machine 10...S1. ] Tool drive circuit 11...Throttle actuator 23...CPU 24...ROM Agent Patent attorney Tsutomu Seitachi-13- Figure 1 Figure 2 Figure 3 Figure 4 A/71= -Noshi 2 75j, θ Fig. 5 1, L-,, l-1-:::II

Claims (1)

[Scope of Claims] In an internal combustion engine of a vehicle equipped with an automatic transmission, a combustion pressure sensor for the cylinder of the engine, a crank angle sensor that detects the crank position in synchronization with the rotation of the crankshaft, and an accelerator opening an accelerator sensor, a vehicle speed sensor, and
A control circuit is provided to control the engine and the automatic transmission based on the signals from each of the sensors, and calculates the required output according to the signal from the accelerator sensor, and satisfies the required output and improves the fuel efficiency or the automatic transmission. A target engine speed and a target indicated average effective pressure of combustion pressure that satisfy the optimum shaft torque for output are determined in advance based on a data map stored in the control circuit,
A method for controlling an internal combustion engine and an automatic transmission, comprising controlling a gear ratio and a throttle opening of the automatic transmission so that the engine is operated at the first revolution speed and the target indicated mean effective pressure. -1-