JPH02125936A - Engine output control device for vehicle - Google Patents

Abstract

PURPOSE:To prevent an abrupt accelerating phenomenon when slip restraining control is completed by the second throttle valve by fully opening the second throttle valve at slower speeds so as to be returned when slip restraining control on a driving wheel is completed. CONSTITUTION:The second throttle valve (e) is provided for the air intake passage (d) of an engine (c) in series with the first throttle valve 6 interlocked with an accelerator pedal (a). An open/close command signal T is outputted from an engine output control circuit (h) to the actuator (f) of the second valve (e) in such a way as to restrain the slip of a driving wheel (g). In this device, the second valve full open return control section (i) is additionally provided for the output control circuit (h). Then, a slip restraining control completion signal E is inputted into the control section (i), and a low opening speed return command TLOW is outputted at the time of the inputting, which fully opens the second throttle valve (e) at an opening speed lower than that at the time of slip restraining control.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention suppresses drive wheel slip by controlling the opening and closing of a second throttle valve that is provided separately from a first throttle valve that is linked to an accelerator pedal. The present invention relates to a vehicle engine output control device that controls engine output to be increased or decreased in a direction that increases or decreases engine output.

(Prior Art) Conventionally, a vehicle engine output control device includes a second throttle valve driven by an actuator in addition to a first throttle valve driven by accelerator operation, and controls the opening and closing of the second throttle valve to suppress drive wheel slip. For example, a device as described in Japanese Patent Application Laid-Open No. 62-45944 is known.

This conventional device controls the rotation of the driving wheels by engine output control (opening/closing control I of the second throttle valve provided auxiliary) so that the frictional force between the tires of the driving wheels and the road surface increases when the vehicle accelerates. I try to do that.

(Problem to be Solved by the Invention) However, in such a conventional vehicle engine output control device, as shown in the timing chart of FIG. 7 of the publication, the throttle opening degree θ5. The drive wheel is returned to the fully open state in a short period of time from the time Tll when the drive wheel slip is suppressed to the time T12, that is, the opening speed is higher than the opening speed during the slip suppression control.

For this reason, for example, if the driver enters a high friction coefficient road from a low friction coefficient road with the first throttle valve fully open or close to fully open, the second throttle valve will suddenly open; Full throttle operation causes the vehicle to accelerate suddenly, giving the driver a sense of fear.

The present invention has been made with attention to the above-mentioned problems, and an object of the present invention is to develop a vehicle engine output control device that can prevent sudden acceleration of the vehicle at the end of drive wheel slender suppression control by the second throttle valve. shall be.

(Means for Solving the Problems) In order to solve the above problems, in the vehicle engine output control device of the present invention, as shown in the claim correspondence diagram of FIG.
The first throttle valve b, which is interlocked with the accelerator pedal a, is connected in series with the second throttle valve e provided in the intake passage d of the engine C, and the valve actuator f of the second throttle valve e prevents the slip of the driving wheels 9. In the engine output control device for a vehicle, the engine output control circuit is configured to output a second valve opening/closing command signal (T) to suppress the slippage of the driving wheels. When the slip suppression control end signal (E) is inputted, the second throttle valve e, which returns to the fully open state, is opened at a speed slower than the opening speed during the slip suppression control. The means is characterized in that it is a circuit having a second valve full-open return control section i that outputs a low opening speed return command signal (T, .W) for returning to full open at the opening speed.

(Function) When a slip occurs in the drive wheels 9 when driving on a road with a low friction coefficient, the engine output control circuit causes the second throttle valve e, which is provided separately from the first throttle valve b, to be activated. A second valve opening/closing command signal (T) is output to the valve actuator f in order to suppress the slip of the driving wheels 9.

Then, the slip of the drive wheels 9 is suppressed due to entry from a low friction coefficient road to a high friction coefficient road, etc., and a predetermined slip suppression control end signal (E) indicating the end of the drive wheel slip suppression control is generated.
is output, the second output of the engine output control circuit
The valve full-open return control unit i receives the slip suppression control end signal (E) as an input signal, and returns the second throttle valve e to the full open state at an opening speed sufficiently lower than the opening speed during the slip suppression control. A low opening speed return command signal (T, .W) is output.

Therefore, at the end of the drive wheel slip suppression control, sudden acceleration of the vehicle due to the rapid return of the second throttle valve e to full opening is prevented.

(Example) Embodiments of the present invention will be described below based on the drawings.

First, the configuration will be explained.

The vehicle to which the engine output control device A of the embodiment is applied is:
As shown in FIG. 2, it includes an engine 1, an automatic transmission 2, a propeller shaft 3, a differential 4, a rear drive shaft 5.6, a rear wheel 7.8 degrees, and front wheels 9, 10.

The engine output control device A operates a second throttle valve 14 provided in the intake passage 13 of the engine 1 in series with the first throttle valve 12 which is interlocked with the accelerator pedal 11, and opens and closes the second throttle valve 14. It includes a throttle motor 15 (actuator) and an engine output control circuit 16 that outputs a second valve opening/closing command signal (T) to the throttle motor 15 in order to suppress slipping of the contact wheels 7 and 8.

The engine output control circuit 16 includes, as an internal circuit, an input circuit +6a that converts an input signal into a digital signal or the like;
CPU16b (central processing unit)
A processing unit), a memory 16c such as a RAM or ROM, and an output circuit +6d for converting into a predetermined analog signal or the like.

The input circuit 16a receives the right front wheel speed detection value VFR from the right front wheel speed sensor 17 and the left front wheel speed detection value V1. and a vehicle speed detection value V from a vehicle speed sensor 19 provided at the output shaft portion of the automatic transmission 2. , the first throttle opening detection value TH from the first throttle opening sensor 20, and the second throttle opening detection value TH from the second throttle opening sensor 21 are input.

In addition, during the control program of the engine output control circuit 16, the end of the driving wheel slip suppression control is determined by the output continuation time of the valve opening command signal exceeding the set timer value △T&J, and when this control end determination is made, When the first throttle opening detection value TH at that time exceeds the second throttle opening detection value TH, the second throttle valve 1 is sent instead of the valve opening command signal during slip suppression control.
Low opening speed return command (■1-ow
) is included.

Next, the effect will be explained.

First, the flow of the slip suppression control operation in the engine output control circuit 16, which is performed every predetermined control activation time Δ, will be explained with reference to the flowchart shown in FIG.

In step 100, the right front wheel speed detection value VFR, the left front wheel speed detection value VFL, the vehicle speed detection value VR, the first throttle opening detection value TH, and the second throttle opening detection value TH2 are read.

In step 101, a front wheel speed detection value VF is obtained by calculating the average value of the right front wheel speed detection value V p R and the left front wheel speed detection value V Fl-.

In step 102, the drive wheel slip rate S is calculated using the detected front wheel speed value V and the detected vehicle speed value VR.

In step 103, when the control is not performed (FLAG・■:0
) or during control (FLAG·■=1).

When FLAG-T=O in step 103, the process proceeds to step 104 and step 105, where the start condition for the sleeve suppression control is determined.

That is, the slip ratio S is greater than or equal to the set value 82 (step 104), and the first throttle opening detection value TH is fully closed (TH
, IN) (step +05), the process proceeds to step 106, and slip suppression control is started by rewriting FLAG.0 to FLAG.1.

Furthermore, when FLAG-T=I is rewritten in step 106, when the control is started thereafter, unless FLAG-T=O is rewritten, the process proceeds from step 103 to step 107 and thereafter, and the second throttle valve 14 is controlled to open and close. Slip suppression control is performed.

In step 107, a threshold value determination of the slip rate S is performed.

That is, if it is determined in step 107 that S≧82, the process proceeds to step 108, and a valve closing command for operating the second throttle valve 14 in the closing direction is output to the throttle motor 15.

Further, if it is determined in step 107 that S<S<57, the process proceeds to step 109, and a valve hold command to hold the second throttle valve 14 at that time is output to the throttle motor 15.

Further, if it is determined in step 107 that S≦81, the process proceeds to step 110, and a valve opening command for operating the second throttle valve 14 in the opening direction is output to the throttle motor 15.

Then, driving wheel slip is suppressed by repeating the cycle of closing the valve, holding the valve, and opening the valve, and when it is determined that the slip suppression control has ended by the output of the valve opening command or the elapse of the set timer value △TV. In step 115 and subsequent steps, the second throttle valve fully open return control is performed.

That is, the determination of the end of the slip suppression control is made in step 110.
If a valve opening command is output after passing , Δt is added to the previous timer value ΣΔt in step 113, and this timer value ΣΔt is added in step 114.
and the set timer value 6-11 are compared, and ΣΔt≧△01
When this happens, it is determined that the slip suppression control has ended.

The set timer value △TM is set as a fixed value or a variable value by cycle monitoring, which is a slightly longer time required from a valve opening command to the next valve hold command during normal slip suppression control, and is set as a fixed value or a variable value by cycle monitoring. If the valve open command is changed to the valve hold command without continuing for the time set timer value ΔTIJ, the previous timer value ΣΔt is cleared (ΣΔt− 0) to be done.

In step 114, when it is determined that ΣΔt≧ΔT&1 and the slip suppression control has ended, step 1
15, the first throttle opening detection value TH at that time,
is compared with the second throttle opening detection value TH2,
When the accelerator pedal 11 is depressed and TH,>TH, the process advances to step 116, and instead of the valve opening command signal during slip suppression control, the second throttle valve 14 is opened at a speed sufficiently higher than that during slip suppression control. A low opening speed return command (T, W) is output to return the second throttle valve 1 to full open at a slow opening speed, and for example, the second throttle valve 1 is
4, and in step +17, τF[8G-T=I is written to FLAG-T=O and I is set.

Also, in step 115, the amount of depression of the accelerator pedal 11 is small and T11. When ≦TH2, there is no risk of sudden acceleration even if the second throttle valve 14 is opened at the valve opening speed during slip suppression control, and
In order to ensure subsequent acceleration, the process proceeds from step 115 to step 118, where it is determined whether the valve opening TH of the second throttle valve 14 is fully open (THuAx), and step 110 is repeated several times. By doing so, the valve opening degree TH of the second throttle valve 14 becomes fully open (THI
JAx), step 119
T=I is rewritten to FLAG・T=0.

Next, referring to FIG. 4, an explanation will be given of the engine output control operation when the vehicle enters a low friction coefficient road from a high friction coefficient road and then enters a high friction coefficient road again.

When entering from a high friction coefficient road to a low friction coefficient road while keeping the accelerator pedal 11 depressed, as shown in the first throttle opening characteristic in FIG.
A so-called driving wheel slip condition occurs in which the wheel speed of the front wheels 9 and 10 increases compared to the wheel speed of the front wheels 9 and 10, which are non-driving wheels.

When this driving wheel slip occurs, the engine output control for suppressing the driving wheel slip is performed at time t in FIG. 4 when the slip rate S exceeds the set value S2. starting from the point in time, and then
As shown in the second throttle opening characteristic by comparing the slip rate S and its threshold value S, , S, it is determined that the second throttle valve 14 repeats the cycle of closing the valve → holding the valve → opening the valve → holding the valve. Valve opening/closing control is performed, and as shown in the driving wheel speed characteristics (characteristics of vehicle speed detection 1 value vR) in FIG. 4, the regression slip of the rear wheels 7.8, which are driving wheels, is suppressed.

When the vehicle enters a high friction coefficient road again from a low friction coefficient road, the drive wheel slip converges due to a change in the road surface friction coefficient.

With the convergence of this drive wheel slip, it is necessary to determine whether the second throttle valve full-open return control is performed or, prior to performing this full-open return control, whether the slip suppression control, which is a starting condition for the full-open return control, has ended.

Therefore, in this embodiment, the end of the slip suppression control is determined when the time t2, which is the set timer value ΔTtl, has elapsed from the time t1 when the last valve opening command is output.

When the time t2 indicating the end of the slip suppression control is reached, the first throttle opening detection value T at that time is reached.
H, is compared with the second throttle opening detection value TH, and when the accelerator pedal 11 is depressed, TH,>TH
, therefore, after time t, the second throttle valve 14 is fully opened at an opening speed sufficiently lower than the opening speed during slip suppression control (for example, from fully open to fully open, 20. control).

Therefore, when entering a high friction coefficient road again from a low friction coefficient road, a slow acceleration state is realized after entering the high friction coefficient road, and as shown by the dotted line characteristic in FIG. 4, the second throttle valve 14 This prevents sudden acceleration after entering a high friction coefficient road, such as when the opening speed is the same as the opening speed during slip suppression control until the opening is returned to full open.

In addition, the condition for starting the second throttle valve full-open return control includes the condition that the first throttle opening detection value TH, exceeds the second throttle opening detection value TH2, so there is a concern about sudden acceleration. When the amount of depression of the accelerator pedal 11 is small, the second throttle valve 14 is opened at the valve opening speed during slip suppression control, and acceleration corresponding to the subsequent depression of the accelerator pedal 11 is ensured.

Although the embodiments have been described above based on the drawings, the specific configuration is not limited to these embodiments, and any changes or additions that do not depart from the gist of the present invention are included in the present invention. It will be done.

For example, in the embodiment, the termination of the drive wheel slip suppression control is determined when the output of the valve opening command passes the set timer value ΔTIJ, but the road surface friction coefficient changes from a low friction coefficient to a high friction coefficient. Other methods may be used, such as by detecting that the acceleration gradient of the driving wheels has changed from a steep gradient to a gentle gradient, or by detecting the accelerator work of the driver.

(Effects of the Invention) As described above, in the vehicle engine output control device of the present invention, the engine output control circuit inputs a predetermined slip suppression control end signal indicating the end of drive wheel slip suppression control. When this slip suppression control end signal is input, a low opening speed return command signal is output that causes the second throttle valve to return to the fully open state at an opening speed that is sufficiently slower than the opening speed during slip suppression control. Since the second valve full-open return control section is included in the engine output control circuit, it is possible to prevent sudden acceleration of the vehicle at the end of driving wheel slip suppression control by the second throttle valve.

[Brief explanation of the drawing]

FIG. 1 is a claim correspondence diagram showing the vehicle engine output control device of the present invention, FIG. 2 is an overall view showing a vehicle to which the vehicle engine output control device of the embodiment is applied, and FIG. 3 is a diagram showing the vehicle engine output control device of the embodiment. FIG. 4 is a flowchart showing the flow of engine output control operation in the example device.
FIG. 4 is a time chart of engine output control operation when traveling on a road surface where the coefficient of friction changes depending on the road surface. a...-Accelerator pedal b...First throttle valve C...Engine d...Intake passage e...Second throttle valve f...Valve actuator 9...Drive wheel h...Engine output Control circuit 1...Second valve full open return control section (T)...-Drive torque increase/decrease command signal

Claims (1)

[Claims] 1) A first throttle valve that is linked with an accelerator pedal is connected in series with a second throttle valve that is provided in the intake passage of the engine, and a valve actuator of the second throttle valve that prevents slippage of the driving wheels. An engine output control device for a vehicle comprising an engine output control circuit that outputs a second throttle valve opening/closing command signal to suppress slip, wherein the engine output control circuit performs a predetermined slip suppression control that indicates the end of driving wheel slip suppression control. A low opening speed return command signal that takes in the end signal as an input signal, and when the slip suppression control end signal is input, causes the second throttle valve, which returns to the fully open state, to return to the full open state at an opening speed that is slower than the opening speed during the slip suppression control. 1. An engine output control device for a vehicle, characterized in that the circuit has a second valve full-open return control section that outputs.