JPH0520574B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automobile equipped with a slip prevention device.
More particularly, the present invention relates to a motor vehicle equipped with a device for preventing wheel slippage.

[Conventional technology]

Conventionally, an automobile equipped with a slip prevention device has been disclosed, for example, in Japanese Patent Application Laid-open No. 116034/1983.

In this conventional vehicle equipped with an anti-slip device, there is a first
In addition to providing a throttle valve, a second throttle valve is provided upstream or downstream of the first throttle valve, and when slip is detected, the second throttle valve is closed to suppress engine output and suppress slip. It's getting old.

Note that the speed at which the second throttle valve is closed is constant, and the opening degree to which the second throttle valve is closed is determined depending on the vehicle speed.

Further, the speed at which the second throttle valve is opened is changed according to the road surface friction coefficient.

[Problem to be solved by the invention]

In the conventional slip prevention device mentioned above, if the speed at which the second throttle valve is closed is too high, engine braking will be applied too rapidly, and conversely, if it is too low, sufficient slip suppression effect will not be obtained quickly. However, there is a problem in that it is difficult to determine the speed.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automobile equipped with a slip prevention device that prevents sudden engine braking and quickly obtains a sufficient slip suppression effect.

[Means for Solving the Problems] An automobile with a slip prevention device of the present invention includes a first throttle valve and a second throttle valve installed in a fuel gas intake path, and the first throttle valve is connected to an accelerator operating section. In an automobile equipped with a slip prevention device in which the second throttle valve is closed by an actuator when a wheel slip is detected, the skip opening of the second throttle valve is rotated at maximum speed. a skip opening setting means for setting the degree of acceleration according to the degree of acceleration of the wheel being moved; and a quick switch for closing the second throttle valve at a relatively high speed until a predetermined skip opening is set by the skip opening degree setting means when a slip is detected. The present invention is characterized in that it includes a control means and a slow control means for closing the second throttle valve at a relatively low speed from the skip opening.

In the above configuration, it is preferable to detect wheel slip by detecting the speed of each wheel, and determining a slip when the difference between the maximum value and the minimum value exceeds a predetermined reference value.

[Effect]

In the present invention, at least two speeds are used to close the second throttle valve, an initial relatively high speed and a final relatively low speed depending on the actual slip situation.

Therefore, a certain slip suppression effect can be obtained without delay in response, and the engine output is also prevented from being excessively suppressed.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on embodiments shown in the drawings. Here, FIG. 1 is a conceptual diagram of the structure of an automobile equipped with a slip prevention device according to an embodiment of the present invention, FIG. 2 is a flowchart of the "starting slip determination" process, and FIG. 3 is a flowchart of the "starting slip prevention" process. , Fig. 4 is a correlation diagram between the first throttle valve opening a and the skip opening _bs , Fig. 5 is a flowchart of the "grip judgment" process, and Fig. 6 is a time chart showing the change in throttle opening over time. Chaat, 7th
The figure is a flowchart showing the procedure of an embodiment of the "start slip prevention" process, and FIG. 8 is a correlation diagram between the acceleration α of the slip wheel and the skip opening _bs . Note that the present invention is not limited to this example.

In the automobile 10 shown in FIG.
A first throttle valve 1 and a second throttle valve 2 are arranged in series with respect to the flow of fuel gas in a fuel gas intake path I to the fuel gas.

The first throttle valve 1 is connected to the accelerator pedal P.
Opens and closes by operating. Further, the second throttle valve 2 is opened and closed by the motor 3.

The opening degree of the first throttle valve 1 is read by an ECU (Electric Control Unit) 5 by an opening sensor 4. Further, the opening degree of the second throttle valve 2 is determined by a command given to the motor 3 by the ECU 5.

Speed sensors 6, 7, 8, and 9 are installed on each wheel W ₁ , W ₂ , W ₃ , and W ₄ , respectively.
The ECU 5 is capable of reading the speed of each wheel W ₁ to _{W 4} .

Next, an example of the operation will be explained with reference to FIGS. 2 to 6.

First, the ECU 5 initially sets the second throttle valve opening b to 100%. Then, the "start slip determination" process shown in FIG. 2 is entered.

In the "start slip determination" process, the speed sensor 6
~9 detects the speed of each wheel _W1 ~ _W4 (S1),
It is checked whether each speed is 0 or not (S2).

If each speed is not 0, it is determined that the car 10 has started, and the maximum speed of each wheel W ₁ to W ₄ is set as the maximum speed V _h , and the minimum speed is set as the minimum speed V _l. Set (S3, S4).

Then, if the minimum speed V _l is less than a predetermined reference speed V _p (for example, 10 Km/h) (S5), it is determined that it is time to start, and then the speed difference ΔV (= V _h − V _l ) is calculated. (S6).

Next, the speed difference ΔV is set to a predetermined reference value V _a (for example, 2
Km/h) or higher (S7),
If ΔV≧V _a , it is determined that a slip has occurred, and the process moves to "start slip prevention" processing.

In the "start slip prevention" process, as shown in FIG. 3, the opening degree a of the first throttle valve 1 is detected by the opening degree sensor 4 (R1).

Next, the skip opening degree _bs is determined based on the opening degree a of the first throttle valve 1 (R2). This is determined based on a predetermined correlation as shown in FIG. 4, for example.

Next, the ECU 5 drives the motor 3 at high speed, thereby closing the second throttle valve 2 at a relatively high speed (for example, 300 degrees/sec) up to the skip opening degree _bs (R3).

When the skip opening is closed to _bs , the motor 3 is driven at a low speed, thereby closing the second throttle valve 2 at a relatively low speed (for example, 3 degrees/sec) (R4).

Then, the process moves to "grip determination" processing.

In the "grip determination" process, as shown in FIG. 5, the speed of each wheel W ₁ to W ₄ is detected (U1), the maximum speed V _h and the minimum speed V _l are extracted (U2, U3), Calculate the speed difference ΔV (=V _h −V _l ) (U4).

Next, the speed difference ΔV is set to a predetermined reference value V _b (for example, 1
Km/h) or less (U5), ΔV≦
If it is not V _b, it is determined that the slip state continues, and the low speed closing operation of the second throttle valve 2 is continued (U6).

When ΔV≦V _b (U5), it is determined that each wheel W ₁ to _{W 4} has sufficient grip, and the motor 3 is driven at a medium speed, thereby driving the motor 3 at a relatively medium speed (for example, 10 degrees/sec).
Open the second throttle valve 2 (U7).

Then, steps U1 to U7 are repeated until the opening degree b of the second throttle valve 2 matches the opening degree a of the first throttle valve 1.

If the opening degree b of the second throttle valve 2 equals the opening degree a of the first throttle valve 1, the "grip determination process" is finished and the process moves to other processes (U8).
Among other processes, the second throttle valve 2
Can be opened to 100%.

FIG. 6 shows changes in the opening degree a of the first throttle valve 1 and the opening degree b of the second throttle valve 2 at each point in time during the above-described operation.

That is, the opening degree a of the first throttle valve 1 is initially opened to about 95%, as shown by the broken line, and is maintained as it is.

On the other hand, the opening degree b of the second throttle valve 2 is initially 100%, but is closed at a relatively high speed at time _t1 , and the opening degree b of the second throttle valve 2 is reduced to a predetermined skip opening degree b _s
Closed until. After time _t2 when the predetermined skip opening degree _bs is reached, the closing operation is performed at a relatively low speed. When it is determined that the wheels W ₁ to _{W 4} have gripped at time t ₃ , the opening operation is performed at a medium speed. At time _t4 , the slip state again occurs, so the closing operation is performed again at a low speed. At time _t5 , the grip of the wheels _W1 to _W4 is detected again, so the opening operation is thereafter performed at a medium speed. At time _t6 , the second throttle valve 2
The opening degree b of the throttle valve 1 matches the opening degree a of the first throttle valve 1, and the "grip determination" process ends. However, after that, the second throttle valve 2 is opened to the 100% opening degree (at time t ₇ ).

Now, in the above procedure, the skip opening degree b _s was determined based only on the opening degree a of the first throttle valve 1. It is effective to determine this based on the acceleration of FIG. 7 shows the "start slip prevention" process in that case.

In other words, the wheel rotating at the highest speed V _h is determined to be the wheel that is slipping, and the predetermined time τ of that wheel is
Calculate the change amount α (Q1 to Q7). Since the amount of change α represents acceleration, this is called the amount of acceleration.

For example, the ECU 5 has a correlation shown in FIG. 8 in advance, and based on this, the acceleration amount α
Determine the skip opening b _s from (Q8). In this case, as is clear from the figure, when the slip is large (acceleration amount α is large), the skip opening is set small and the opening of the second throttle valve 2 is greatly corrected, so that the slip is When the acceleration amount α is small (the acceleration amount α is small), the skip opening degree is set relatively large and the opening degree of the second throttle valve 2 is corrected to be small. This prevents excessive deceleration during slip prevention control.

Once the skip opening b _s is determined, the second throttle valve 2 is closed at a relatively high speed until the skip opening b _s is reached (Q9), and then at a relatively low speed (Q10). The process moves on to "Grip Judgment" processing.

As can be understood from the above description, in the vehicle 10 with the slip prevention device of the present invention, when a slip is detected, the second throttle valve 2 first opens a predetermined skip at a relatively high speed according to the actual slip situation. is operated closed to degrees b _s , then wheels W ₁ ~
The closing operation is performed at relatively low speed until W ₄ grips. Therefore, by closing the skip to a predetermined skip opening degree _bs at a relatively high speed, a delay in response can be prevented, and the minimum necessary slip prevention effect can be quickly obtained. Furthermore, after obtaining the minimum necessary slip prevention effect, the closing operation is performed at a relatively low speed until sufficient wheel grip is obtained, so that sufficient slip prevention effect can be obtained without causing inconveniences due to excessively sudden engine braking. It will be.

〔Effect of the invention〕

According to the present invention, the first throttle valve and the second throttle valve are installed in the fuel gas intake path, and the first throttle valve opens and closes in conjunction with the accelerator operation section, and the second throttle valve In a vehicle equipped with a slip prevention device that uses an actuator to close the door when wheel grip is detected, the skip opening method sets the skip opening degree of the second throttle valve in accordance with the degree of acceleration of the wheel rotating at maximum speed. a speed setting means, a quick control means for closing the second throttle valve at a relatively high speed up to a predetermined skip opening set by the skip opening setting means when a slip is detected; An automobile equipped with a slip prevention device is provided, characterized in that it is equipped with a slow control means for closing a slip valve at a relatively low speed, thereby making it possible to carry out suitable slip prevention control according to the actual slip situation. At the same time, a sufficient slip prevention effect can be obtained while avoiding sudden changes in vehicle speed due to excessively rapid engine braking.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the structure of an automobile equipped with a slip prevention device according to an embodiment of the present invention, FIG. 2 is a flowchart of the "starting slip determination" process, FIG. 3 is a flowchart of the "starting slip prevention" process, and FIG. Fig. 4 is a correlation diagram between the first throttle valve opening a and the skip opening _bs , Fig. 5 is a flowchart of the "grip judgment" process, Fig. 6 is a time chart showing changes in the throttle opening over time, FIG. 7 is a flowchart showing the procedure of an embodiment of the "start slip prevention" process, and FIG. 8 is a correlation diagram between the acceleration α of the slip wheel and the skip opening _bs . Explanation of symbols, 1...First throttle valve, 2
...Second throttle valve, 3...Motor, 5...
...ECU, 6 to 9...Speed sensor, 10...Automobile with anti-slip device, I...Fuel gas intake path.

Claims (1)

[Claims] 1. A first throttle valve and a second throttle valve are installed in a fuel gas intake path, and the first throttle valve is opened and closed in conjunction with an accelerator operation section, and the second throttle valve is opened and closed in conjunction with an accelerator operation section. In automobiles equipped with a slip prevention device in which the valve is closed by an actuator when wheel slip is detected, the skip opening of the second throttle valve is set in accordance with the degree of acceleration of the wheel rotating at maximum speed. opening setting means; quick control means for closing the second throttle valve at a relatively high speed up to a predetermined skip opening set by the skip opening setting means when a slip is detected; An automobile equipped with a slip prevention device, characterized in that it is equipped with slow control means for closing a throttle valve at a relatively low speed.