JPS6267243A - Engine control of vehicle installed automatic transmission - Google Patents

Abstract

PURPOSE:To gain the number of engine rotations responding to the will of a driver in a gear change, by computing an aimed number of engine rotations after the gear change, from the gear ratio after the gear change, and the car speed and the accelerator pedal pressing amount before the gear change, while controlling the fuel feeding amount to get the aimed number of engine rotations. CONSTITUTION:A processor 31a of an electronic control unit 31 computes the number of engine rotations No after the gear change, from the car speed before the gear change and the gear ratio after the gear change, when the car speed is being changed and the clutch 13 is disconnected. Then a correcting coefficient K responding to the accelerator pedal 26 pressing amount is found from a map and the final object number of engine rotation No' is found by multiplying the engine rotations No after the gear change by the correcting coefficient K. By a feedback control from the difference between the object engine rotations No' and the actual engine rotations Ne, a throttle actuator 30 is controlled. After the gear change is over, the clutch 13 is connected and the throttle position is controlled depending on the accelerator pedal pressing amount.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an engine control method for a vehicle equipped with an automatic transmission that performs gear change control based on a control signal output from an electronic control device depending on the driving state of the vehicle. Regarding.

(Prior art) In vehicles equipped with automatic transmissions, automatic transmission is automatically controlled depending on the engine load, that is, the amount of accelerator pedal depression or throttle valve opening, or the fuel control lever of the fuel injection device (hereinafter referred to as throttle opening), and the vehicle speed. A gear shifting operation is performed.

That is, the electronic control device that controls the transmission etc. stores a shift pattern corresponding to the throttle opening and the vehicle speed.
Shift control is performed based on this shift pattern. Figure 4 is an example of a shift pattern, with the vertical axis representing throttle opening and
In the diagram, which shows vehicle speed (km/h) on the horizontal axis, the solid line is the automatic shift line when shifting up, the broken line is the automatic shifting line when downshifting, and FSA, SSA, and TSA are the 1st speed range, respectively. These are the 2nd speed area and the 3rd speed area. Now, assuming that the throttle opening and vehicle speed are changing along the dashed line, when the operating point exceeds point P when the speed increases, the gear will automatically shift from 1st gear to 2nd gear, and Point) If Q is exceeded, the gear will automatically shift up from 2nd gear to 3rd gear. On the other hand, when speed decreases, when point Q' is exceeded, a downshift from 3rd speed to 2nd speed is performed, and when point P' is exceeded, a downshift from 2nd speed to 1st speed is automatically performed.

In such conventional vehicles with automatic transmissions, the throttle valve is returned by a predetermined amount when changing gears in order to prevent the engine from revving up. This reduces the vehicle's load on the engine when shifting, and for this reason, unless the throttle valve is set small, the engine speed increases (engine speed).
Because it does.

By the way, the throttle return position Is is determined by the following formula, where A is the current accelerator opening, as follows: S=α·A (1) (where α is a constant number, for example, 0.5). However, if α in equation (1) is held constant as described above, the engine may still rev up during gear changes depending on the amount of depression of the accelerator. For example, if the vehicle speed in low gear (L speed) is relatively high (accelerator depression amount is large) and 2nd gear is to be upshifted, the throttle should be adjusted using formula (1) because the accelerator depression amount is large. Even if the amount determined by is returned, the amount returned is not enough and the engine will rev up. Incidentally, if α in equation (1) is increased, engine revving will not occur, but the vehicle speed before and after the shift cannot be maintained constant, which is inconvenient and reduces the riding feeling.

In order to eliminate such problems, the engine speed after shifting is calculated from the gear ratio after shifting and the vehicle speed before shifting.
Japanese Patent Laid-Open No. 8436/1983 has proposed a system in which the throttle opening degree is controlled to achieve the engine speed.

(Problems to be Solved by the Invention) However, in the above publication, for example,
When downshifting to apply engine braking during deceleration, the throttle is controlled so that the target engine speed corresponds to the higher vehicle speed before shifting, even though the engine speed decreases during the shift. As a result, the actual engine speed is higher than the required engine speed after shifting, and a shock occurs on the acceleration side after shifting.
There is a problem in that it causes discomfort to the driver. In addition, when the driver wants to accelerate overtaking by kicking down, it is preferable to increase the engine speed according to the driver's will, but in the system disclosed in the above publication, the vehicle speed before shifting is The target engine speed is determined accordingly, and in such a case, the engine speed may be insufficient compared to the driver's intention, causing a problem that acceleration may be a little sluggish.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a throttle control method that can obtain an engine speed that corresponds to the driver's intention during gear shifting.

(Means for Solving the Problem) According to the present invention, there is provided an engine control method for a vehicle equipped with an automatic transmission, which performs gear change control based on a control signal output from an electronic control device depending on the driving state of the vehicle. , the electronic control device calculates a target engine speed after the shift based on the gear ratio after the shift, the vehicle speed before the shift, and the amount of depression of the accelerator pedal, and controls the fuel supply amount so as to reach the target engine speed. An engine control method for a vehicle equipped with an automatic transmission is provided.

(Function) In the present invention, the engine speed after the shift is calculated from the gear ratio after the shift and the vehicle speed before the shift, and the engine speed after the shift is corrected by the amount of depression of the accelerator pedal to achieve the target after the shift. The engine rotation speed is determined, and the fuel supply amount is controlled so as to reach the target engine rotation speed.

(Examples) Hereinafter, the present invention will be specifically described based on illustrated examples.

FIG. 1 is a block diagram showing an embodiment of a vehicle equipped with an automatic transmission that implements the present invention. In the figure, 11 is an engine, 12 is a flywheel of the engine 11, 13 is a clutch, and 14 is a clutch actuator that connects and disconnects the clutch 13. In this embodiment, this is composed of a hydraulic actuator, and its piston The actuation of the rod 15 causes the clutch release lever 16 to be actuated to disconnect or engage the clutch 13. The operating position of the clutch actuator is detected by a clutch stroke sensor 14a, and the detection signal is input to an electronic control device 31, which will be described later. Reference numeral 17 denotes a hydraulic mechanism that applies hydraulic pressure to the clutch actuator 14. Reference numeral 18 denotes an engine rotation sensor for detecting the engine rotation speed, which is disposed opposite to the flywheel 12, and inputs its detection signal to an electronic control unit 31, which will be described later. 19 is an input shaft of the transmission 20, 22 is an output shaft of the transmission 20,
Reference numeral 23 denotes a vehicle speed sensor that detects the rotational speed of the outboot shaft 22, and inputs its detection signal to an electronic control device 31, which will be described later. Reference numeral 21a is a speed change actuator that performs a speed change operation of the transmission 20, and is connected to the hydraulic mechanism 18. 2tb is a gear position sensor that detects the shift position of the transmission 20, and inputs its detection signal to an electronic control unit 31, which will be described later. 24 is a select lever operated by the driver, 25 is a select position detection sensor that detects the operating position of the select lever 24, and inputs the detection signal to an electronic control unit 31, which will be described later. 26 is an accelerator pedal, 27 is an accelerator pedal sensor that detects the amount of depression of the accelerator pedal 26, and inputs the detection signal to an electronic control device 31, which will be described later. 28 is a carburetor of the engine 11, 29 is a throttle valve, and 30 is a throttle actuator for operating the throttle valve 29, which is constituted by, for example, a step motor. Although this embodiment uses a carburetor as the fuel supply means for the engine 11, it goes without saying that the fuel supply means may also be a fuel injection device. In this specification, this is referred to as throttle control.

The electronic control device 31 is configured by a microcomputer, for example, and includes a processor 31a that executes arithmetic processing based on a control program, and a read-only memory 31b.
, a readable/writable data memory 31c for storing calculation results and input data of the processor 31a, an input/output interface 31d, and the like. The memory 31b stores a control program for automatic shift control, a shift pattern as shown in FIG. 4, and the like.

The electronic control device 31 includes the clutch stroke sensor 1
4a, based on input signals from engine rotation sensor 18, gear position sensor 21b, vehicle speed sensor 23, select position sensor 25, accelerator pedal sensor 27, etc., shift control, that is, clutch actuator 14, shift actuator 21a, throttle actuator 30, etc. control. That is, the electronic control device 31 uses the shift pattern shown in FIG. When the shift line at is reached, the clutch actuator 14 is actuated to disengage the clutch 13, the shift actuator 21a is actuated to change the gear of the transmission 20,
Thereafter, the clutch actuator 14 is operated to connect the clutch 13. During this gear shifting operation, the electronic control device 3
Reference numeral 1 controls the throttle actuator 30. During the gear shifting operation, the electronic control unit controls the throttle opening. Throttle control during gear shifting will be described below with reference to the flowchart shown in FIG.

(a) The processor 31a of the electronic control unit 31 determines whether or not the gear is being shifted, and if the gear is being shifted, determines whether the clutch is disengaged, and if the clutch is disengaged, Calculate the engine speed after shifting. That is,
The vehicle speed before shifting is ■ (km/h), the tire effective radius is r,
The gear ratio after shifting is in, the final gear ratio is if, and the engine speed after shifting is N. Then, the following formula holds true. Therefore, the engine speed NO after shifting is
From the vehicle speed ■ before shifting and the gear ratio 1m after shifting, No=C*V@im (3) (However, C is i
It is a constant that depends on f and r. ), the processor 31a calculates the engine rotational speed NO after the gear shift using equation (3).

(B) Next, the processor 31a obtains a correction coefficient (K) corresponding to the amount of depression of the accelerator pedal from the map shown in FIG. The final target engine speed No' is calculated by multiplying the engine speed NO.

No' = @No (4) As shown in Fig. 3, the correction coefficient (K) is less than 1 in the range where the amount of accelerator depression is small, and it is less than l or -L when the amount of accelerator depression is near the maximum. It is set to be. Therefore,
The target engine speed No' is the engine speed No. after shifting in the engine braking state when the accelerator pedal is released.
It becomes lower, and at the time of kickdown when the accelerator pedal is depressed to the maximum, it becomes higher than the engine rotation speed No. after shifting.

(c) In step (b), the target engine speed NO'
Once obtained, the processor 31a controls the throttle actuator 30 by feedback control based on the difference between the target engine speed No' and the actual engine speed Ne.

(iv) Next, the processor 31a monitors the output of the gear position sensor 21b and determines whether the gear change has been completed.

(e) If the gear change has not been completed, the processor 31a repeats the processing from step (a) onward; on the other hand, if the gear change has been completed, the processor 31a
operates the clutch actuator 14 to close the clutch 13.
The throttle position is controlled according to the amount of depression of the accelerator pedal 26.

1-1 The present invention has been explained based on the illustrated embodiments, but
The present invention is not limited to only those shown in the examples, and various modifications are possible within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) The present invention calculates a target engine speed from the gear ratio after shifting, the vehicle speed before shifting, and the amount of depression of the accelerator pedal, and controls the fuel supply amount so that the target engine speed is achieved. This prevents the engine from revving when changing gears, and when downshifting during deceleration, the engine speed is lowered according to the driver's intention to press the accelerator pedal, resulting in engine braking. works smoothly to improve safety, and when overtaking with a kickdown, the engine speed increases according to the driver's intention to press the accelerator pedal to obtain sufficient acceleration power. It has effects such as being able to.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of a vehicle equipped with an automatic transmission implementing the present invention, Fig. 2 is a flowchart showing an embodiment of the engine control method according to the invention, and Fig. 3 corresponds to the amount of accelerator depression. FIG. 4 is a map diagram showing correction coefficients to be used, and FIG. 4 is a diagram showing an example of a shift pattern. 11...Engine, 13...Clutch, 14...
Clutch actuator, 18... Engine rotation sensor, 20... Transmission, 21a... Speed change actuator, 21b... Gear position sensor, 24... Select lever, 25... Select position sensor, 26...
...Accelerator pedal, 27...Accelerator pedal sensor, 30...Throttle actuator, 31...Electronic control device.

Claims (1)

[Claims] An engine control method for a vehicle equipped with an automatic transmission that performs speed change control based on a control signal output from an electronic control device depending on the driving state of the vehicle, the electronic control device controlling the gear ratio after the speed change and the gear ratio before the speed change. A method for controlling an engine for a vehicle equipped with an automatic transmission, comprising calculating a target engine speed after shifting from a vehicle speed and an amount of depression of an accelerator pedal, and controlling a fuel supply amount so as to reach the target engine speed.