JPS60107430A - Slip prevention device for car - Google Patents

Abstract

PURPOSE:To improve running stability, accelerationand drivability by arranging a torque control means which controls fuel supplying quantity based on a first slip judgment and performs ignition cutting control based on a second slip judgment. CONSTITUTION:A torque control means e, which controls fuel supplying quantity based on judgment of a first slip judging means c and performs ignition cutting control based on judgment of a second slip judging means d, is provided. And a first slip judgment level and a second slip judgment level which is higher than the former are set based on the speed of a driven wheel, and when the speed of a driving wheel exceeds the first slip judgment level, fuel cutting is performed and at the same time, when it exceeds the second slip judgment level, ignition cutting is performed. Thereby, excessive slip which occurs due to delay of response of fuel control is restrained, speed of the driving wheel is well controlled, and running stability is improved.

Description

[Detailed Description of the Invention] [Technical Field] -1- The present invention relates to a slip prevention device for a vehicle,
In particular, the present invention relates to a vehicle slip prevention device that prevents excessive slip when starting or accelerating a vehicle.

[Prior Art] Conventionally, a slip prevention device for a vehicle has been proposed that suppresses engine torque by cutting fuel from the engine when the vehicle slips, for example.

However, there is generally a delay between when fuel is supplied to the engine and when engine torque is generated, and this delay varies depending on the engine speed. In other words, when the engine speed is high, the delay is small, and when the engine speed is low, the delay is large. Therefore, if a sudden slip occurs on a road surface with an extremely low coefficient of friction when the engine speed is low, excessive slip will occur before the fuel cut starts to suppress the slip, causing the vehicle to become unstable. there were.

[Objective of the Invention 1 The present invention has been made in view of the above-mentioned points. -2- Its purpose is to improve running stability, acceleration, and drivability by controlling the fuel supply amount and shutting off the ignition. An object of the present invention is to provide an anti-slip 1F device that improves the slip resistance.

[Structure of the Invention] The structure of the present invention for achieving the above object is as shown in the basic configuration diagram in FIG. The driven wheel speed detection means includes first slip determination means C for determining whether or not the driving wheel speed exceeds a first slip determination level set based on the driven wheel speed; a second slip determination means d that determines whether the drive wheel speed exceeds a second slip determination level set higher than the first slip determination level; and fuel supply based on the determination of the first slip determination means C. The gist of this invention is a slip prevention device for a vehicle, characterized in that it is equipped with a torque control means e that controls the amount of torque and performs ignition cutoff control based on the determination of the second slip determination means d.

[Example] The present invention will be explained below by giving examples and referring to the drawings.

FIG. 2 is a block diagram of the anti-slip device of the present invention. In the figure, 1 is a driving wheel speed sensor that detects the driving wheel speed;
2 is a driven wheel speed sensor that detects the driven wheel speed; 3 is a slip control device consisting of a microcomputer that cuts fuel when a slip occurs; and 4 is a fuel supply device that supplies appropriate fuel to the engine according to the operating state of the engine. , 5 is an ignition device for igniting the engine. and,
In the slip control device 3, 31 is a central processing unit (hereinafter referred to as CPU) that performs calculations such as slip determination, etc.
2 is a counter that counts the pulse width of speed sensors 1 and 2;
33 is an input device for inputting the signals of speed sensors 1 and 2;
4 is a random access memory (hereinafter referred to as RAM) that temporarily stores calculation results, etc., and 35 is a read-only memory (hereinafter referred to as R) that stores calculation programs and control data.
36 is an output device that outputs a control signal to the fuel supply device 4 and the ignition device 5.

The slip control device 3 determines slip from the speed signals of the speed sensors 1 and 2, and when a slip occurs, the output device 36 instructs the fuel supply device 4 to cut fuel to reduce engine torque and suppress slip. .

Furthermore, in the embodiment, the slip control device 3 determines excessive slip based on the speed signals of the speed sensors 1 and 2, and when an excessive slip occurs, cuts the ignition to the ignition device 5 and immediately A command is issued from the output device 36 to reduce the engine torque and suppress excessive slip.

The driving wheel speed sensor 1 is used as the driving wheel speed detection means a, the driven wheel speed sensor 2 is used as the driven wheel speed detection means, and the slip control device 3, the fuel supply device 4 and the ignition device 5 are used as the first slip determination means C1. This corresponds to the second slip determination means d and the torque control means e, respectively.

Next, the detailed operation of the slip-5 control device 3 using a microcomputer will be explained with reference to the flowchart of FIG. First, when the process starts, step 10
0, the driving wheel speed Vw is calculated from the output of the driving wheel speed sensor 1, the driven wheel speed VV is calculated from the output of the driven wheel speed sensor 2 in step 101, and the driven wheel speed VV is calculated in step 102. (K=1.1~2)l, T 1st
Let the slip judgment level be yt. In the following step 103, a slip is determined by comparing the driving wheel speed VW and the first slip determination level Vt, and if VW≦Vt is established and it is determined that there is no slip, the process jumps to step 108 and resets the fuel cut signal. 1 and instructs the fuel supply device 4 to supply normal fuel through the output device 36.

In the following step 109, the ignition cut signal is reset and the ignition device 5 is commanded to perform normal ignition via the output device 36, and the process returns to step 100.

On the other hand, if Vw > Vt is satisfied and it is determined that there is a slip in step 103, a fuel cut signal is set in step 104, and fuel (λ/ 1 and commands to perform a fuel cut.Next, in step 105, the driven wheel speed VV is multiplied by '(K<K-; -=1.2 to 2.5) to set the second slip judgment level VS. In step 105, the driving wheel speed VW is compared with the second slip determination level VS to determine whether the currently occurring slip is an excessive slip.

If it is determined in step 105 that Vw≦ys is established and there is no excessive slip, the process goes to step 109, where the ignition cut signal is reset and the ignition device 5 is commanded to perform normal ignition via the output device 36. , step 100
Return to

On the other hand, if it is determined in step 106 that Vw>Vs is established and excessive slip has occurred, an ignition cut signal is set in step 107 and sent to the ignition device 5 via the output device 36. A command is given to stop the ignition, the process returns to step 100, and the same process is repeated thereafter. In this case, the ignition cut is about 1 to 3 ignition cuts, and there is almost no adverse effect on the engine or the catalyst.

-7- As a result, when there is no slip, normal fuel supply and ignition are performed, and when slip occurs, fuel cut is performed.
Furthermore, when the slip becomes excessive, a fuel cut and an ignition cut are performed.

FIG. 4 shows an example of the operation of this embodiment. In the figure, the solid line waveform is the driving wheel speed VW, the solid line is the driven wheel speed Vv, the dotted line is the first slip judgment level Vt, the second slip judgment level VS, and the dashed line is the driving wheel speed when only one combustion cut is performed. Each represents the speed VW.

During constant speed running, the driving wheel speed VW and the driven wheel speed Vv are equal. When acceleration starts at time ta, the driving wheel speed v
W increases rapidly and driven wheel speed Vv increases almost linearly. At time tb, the driving wheel speed VW is the driven wheel speed VV.
When the slip determination level Vt becomes equal to the first slip determination level Vt determined by , and the time point tb has passed, the fuel cut is started, but due to the fuel response delay, the engine torque does not decrease and the driving wheel speed VW increases. At time tc, the driving wheel speed Vw is at the second
becomes equal to the slip judgment level VS, and the time tc has passed.
8 = When the engine reaches 8, the ignition is cut off along with the fuel cut.

Conventionally, the driving wheel speed VW overshoots as shown by the dashed line in FIG. 4, causing excessive slip, which makes the vehicle unstable and dangerous.

However, in the embodiment, when the occurrence of excessive slip is detected, the ignition cut with very little control response delay is performed together with the fuel cut for a very short period of time, thereby reducing the engine torque and suppressing the slip by reducing the drive wheel speed [ Vw decreases rapidly. At time td, the driving wheel speed Vw becomes equal to the second slip determination level Vs again, the ignition cut is stopped, normal ignition is performed, only the fuel cut is performed, and the driving wheel speed VW gradually decreases.

At time te, the driving wheel speed VW becomes equal to the first slip determination level yt, the fuel cut is stopped, normal fuel supply is performed, and the driving wheel speed VW is gradually accelerated. At the time point "if", it becomes equal to the first slip judgment level Vt again, and after the time point "t", the fuel cut is restarted again, the engine torque is suppressed and the drive wheel speed VW is suppressed, and the first slip judgment level -〇 constant level V1 This process is repeated until the driving wheel speed vw reaches the first slip determination level Vt.
It will be kept nearby.

As described in detail above, in this embodiment, when the driving wheel speed VW exceeds the first slip judgment level Vt which is the predetermined times the driven wheel speed VV, the fuel is cut, and the driving wheel speed VW
is configured to cut the ignition when it exceeds a second slip determination level VS, which is set higher than the first slip determination level.

Therefore, when excessive slip occurs, the engine torque can be sufficiently suppressed to suppress the slip.

In this embodiment, slip control may be performed using an analog circuit instead of a microcomputer, and fuel cut may be performed by switching the number of cylinders to which fuel is cut depending on the engine speed. The amount of fuel supplied to each cylinder may be changed depending on the amount of fuel supplied to each cylinder. In other words, the engine torque may be reduced by cutting the fuel when the engine speed is high and increasing the air-fuel ratio when the engine speed is low, but this implementation is not limited to either method as long as the gist of the present invention is not exceeded. The examples are not limited.

[Effect of the invention 1] The present invention sets a first slip judgment level and a second slip judgment level higher than the first slip judgment level based on the driven wheel speed, and when the driving wheel speed exceeds the first slip judgment level, The fuel cut is executed when the slip is exceeded, and the ignition cut is executed when the second slip determination level is exceeded.

Therefore, when the engine speed is low and the vehicle is traveling on a road surface with a low road surface friction coefficient, excessive slip that occurs due to a delay in control response can be quickly suppressed.

It goes without saying that slips can also be suppressed well in cases other than those described above.

Therefore, it is possible to suppress excessive slip that occurs due to a delay in fuel control response, to satisfactorily suppress drive wheel speed, and to improve running stability.

In addition, acceleration and drivability can be ensured. There is also the effect of saying.

Another side effect is that it can suppress the unpleasant skidding noise that occurs when starting off.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram of the present invention, Fig. 2 is a block diagram of the embodiment, Fig. 3 is a flowchart of the control program of the embodiment, and Fig. 4 is a graph showing the operating status of the embodiment. represent. 1... Drive wheel speed sensor 2... Driven wheel speed sensor 3... Slip control I device 4... Fuel supply device 5... Ignition device 31... CPU 32... Counter 34...・RAM 35...ROM Agent Patent attorney Tsutomu Adachi and 1 other person -12-

Claims (1)

[Claims] Drive wheel speed detection means for detecting the drive wheel speed, driven wheel speed detection means for detecting the driven wheel speed, and the driven wheel i! !
a first slip determination means for determining whether or not the driving wheel speed exceeds a first slip determination level set based on the driven wheel speed; a second slip determination means for determining whether or not the driving wheel speed exceeds a two-slip determination level; and a fuel supply amount is controlled based on the determination by the first slip determination means; 1. A slip prevention device for a vehicle, comprising: a torque control means that performs ignition cutoff control based on the ignition cutoff control.