JPS63134359A - Antiskid device for motorcycle - Google Patents

Abstract

PURPOSE:To carry out the optimum antiskid control under whatever road surface condition by providing a switchover device for switching over the set value of a comparing device when the generation of a slip signal is continued for more than a defined time. CONSTITUTION:Defined two large and small deceleration references are set in a deceleration signal generating circuit 7, and are switched over by the output of an on/off delay timer 9 connected to a slip signal generating circuit 4, and a signal-b is generated when a detected wheel deceleration exceeds the selected reference value. Accordingly, when a slip signal continues longer than a defined time, the set value of the deceleration signal-b is switched over to be small to carry out a control suited to the case of a road surface mu, or, when the slip signal is short, since the set value-b is left large, a control suited to the case of a large road surface mu can be carried out. Thereby, the optimum antiskid control can be carried out under whatever road surface condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an anti-skid device for a two-wheeled vehicle (motorcycle) that prevents wheels from skidding during braking.

[Conventional technology and its problems]

For example, in Japanese Patent Application Laid-Open No. 56-142735, the reference deceleration set in the deceleration signal generator is a fixed value, but optimal control cannot be performed under driving conditions where the road surface friction coefficient μ changes significantly. In other words, when a slip signal occurs, the brakes are released, but with a low coefficient of road friction, the slip signal continues for a long time, and the wheels become difficult to decelerate, so the brakes are released only after a predetermined deceleration is reached. If it is too long, the braking distance will be significantly longer.

[Problem that the invention seeks to solve]

The present invention was made in view of the above problems, and an object of the present invention is to provide an anti-skid device for a two-wheeled vehicle that can perform optimal control under any road surface conditions.

[Failure to solve the problem]

The above purpose is to compare a wheel speed detection device that monitors the rotational state of the wheels and detects the wheel speed, a vehicle speed generator that generates an approximate vehicle speed based on the wheel speed, and the wheel speed and approximate vehicle speed. a slip detection device that generates a slip signal when the difference between the two reaches a predetermined value based on a predetermined relationship;
A differentiating device that differentiates the wheel speed to generate a wheel acceleration, and a comparator that generates a deceleration signal when the wheel acceleration reaches a negative set value, and in response to generation of the slip signal and the deceleration signal. This is achieved by an anti-skid device for a two-wheeled vehicle capable of reducing brake pressure, which is provided with a switching device that switches the set value of the comparator when the generation of the slip signal continues for a predetermined period of time.

[For production]

If the slip signal continues for a long time, the set value of the deceleration signal can be changed to a small value, which is suitable when the road surface μ is small, or
If the slip signal is short, the set value of -b remains large, so that appropriate control can be performed when the road surface μ is large.

〔Example〕

Hereinafter, details of the present invention will be explained based on illustrated embodiments.

The drawing shows a block diagram of an anti-skid device according to an embodiment of the present invention applied to a motorcycle. Represents a mounted wheel speed sensor that generates a signal with a frequency proportional to the rotational speed of the wheel. This signal is supplied to the wheel speed calculation circuit (2), which generates an analog output proportional to the wheel speed, and outputs it to a differentiating circuit (5), an approximate vehicle speed calculation circuit (3), and an analog output proportional to the wheel speed. The signal is supplied to the slip signal generation circuit (4). A predetermined slip rate is set in the slip signal generating circuit (4), and is set to 15 in this embodiment.

Approximate vehicle speed calculation circuit (3) is wheel speed calculation circuit (2)
until the deceleration of the wheels reaches a predetermined value, an output equal to the wheel speed is generated, and when the deceleration of the wheels exceeds the predetermined value, the wheel speed at that point is set to the initial value. , an approximate vehicle speed is generated that decreases at a predetermined slope thereafter. The output from the approximate vehicle speed calculation circuit (3) is supplied to a slip signal generation circuit (4).

In the slip signal calculation circuit (4), the above set rate of 15% is compared with the value (slip rate) obtained by subtracting the percentage of the wheel speed to the approximate vehicle speed from 100, and if this slip rate is larger than the set rate, the slip signal is A generating circuit (4) generates a slip rate signal λ. This is fed to one input terminal of AND gate east.

The output terminal of the differentiation circuit (5) is the acceleration signal generation circuit (6)
, is connected to the deceleration signal circuit (7). A predetermined acceleration reference value, for example 0.5f, is set in the acceleration signal generation circuit (6), and when the detected wheel acceleration exceeds 0.5t, the acceleration reference value is generated, which is described above. is supplied to the other negative input terminal of the AND gate συ.

The deceleration signal generation circuit (7) is set with two predetermined deceleration reference values, for example -1, Of and -1,5F, which are connected to the slip signal generation circuit (4). Switched by the output of the on-off delay timer (9), a deceleration signal is generated when the detected wheel deceleration exceeds this selected reference value. The output of the deceleration signal generating circuit (7) is supplied to one input terminal of an anti-gear (11), and is supplied to the other input terminal via a timer (8). 10 for timer (8)
Hsec is set, the input to it becomes "1" and becomes "1", but from now on 101rLSeC
When elapses, an output that becomes ``0#'' is generated.

The output terminal of the AND gate αQ is the final stage OR gate for loosening (
2), and the output terminal of the above-mentioned AND gate ση is connected to this first input terminal.

The on/off delay timer (9) has an on delay time of 200771 seconds and an off delay time of 5007 seconds.
If 71 sec is set, the slip signal generation circuit (
A slip signal λ is generated from 4) and this is 200rrLs.
If it continues for more than ec, the output of this timer (9) will be @1”
Tonanashi, even if the slip signal λ disappears from now on, 500g5e
c is designed to maintain this output 11''.In other words, 200rnBee is the time when the slip signal λ is considered to continue for a sufficiently long time, and 500771 sec.
is a sufficiently longer time than one anti-skid control time.

The output terminal of the OR gate is connected to the solenoid section C14 of the solenoid valve via an amplifier. Although not shown,
The mask cylinders are connected to front and rear wheel cylinders via electromagnetic valves, respectively.

When the solenoid part α◆ is energized, the mask cylinder side and the wheel cylinder side are cut off, but the wheel cylinder side and the reservoir side are communicated, and the pressure fluid in the wheel cylinder is discharged to the reservoir and the brake is released. It is now possible to The brake fluid discharged from the wheel cylinder into the reservoir is pressurized by the hydraulic pump and returned to the pressure fluid supply pipe.

The anti-skid control device according to the embodiment of the present invention is constructed as described above, and its operation will be explained below.

Now, suppose that the motorcycle is running at a constant speed and you start operating the brakes on the front and rear wheels.

The wheel speeds of the front wheels and the rear wheels are detected by a wheel speed sensor (1) (the circuit will be described only for the front wheels), and a wheel speed signal is formed by a wheel speed calculation circuit (2).
These are differentiated by a differentiating circuit (5).

The output of the differential circuit (5), that is, the deceleration, is compared with the larger reference value of the deceleration generating circuit (7), but it has not yet reached this value, and the wheel slip is still at a predetermined level at the beginning of braking. Since the value does not reach 15ch, the slip signal generating circuit (4) does not generate the slip rate signal λ. Therefore, since neither the slip rate signal nor the deceleration signal is supplied to the OR gate (2), the solenoid (B) of the electromagnetic valve is not energized. Therefore, when the brake operation is started, the brake fluid pressure from the mask cylinder is applied to the brake fluid pressure cylinders of the front and rear wheels through the valve.

As described above, the brakes are applied to the front and rear wheels.Assuming that you are currently driving on a road surface with a high friction coefficient, if the slip rate exceeds 15, a slip signal is sent from the slip signal generation circuit (4). λ occurs. Since the acceleration signal signal S is not generated now, the output of the AND gate (lη) and therefore the output of the OR gate (B) is "11". The solenoid part (B) is energized. Therefore, the brake of the wheel is released.

The speed at which the wheels decelerate varies depending on the brake gain, the speed at which the brake pedal is depressed, the condition of the road surface, etc., but it is assumed that the deceleration has now exceeded -1.51. That is, a signal is generated from the deceleration signal generation circuit (7) (for the sake of clarity, it is assumed that the front and rear wheels are equally decelerated).As a result, the output of the AND gate αQ is Therefore, the output of OR gate (2) is "1". Therefore, the solenoid portion Q41 is energized and the pressure fluid in the front and rear wheel cylinders is discharged into the reservoir. The brakes on the front and rear wheels are released, but when the set time 10@see of the timer (8) has elapsed, the output of the AND gate αQ becomes 10'', the brake release is completed, and the brakes are applied again. Power increases.

In the above description, it is assumed that the automobile is traveling on a road with a high coefficient of friction and the slip signal λ does not last long and suddenly disappears. Therefore, the output of the on/off delay timer (9) remains in the positive state, and the larger reference value -1, 5f is selected in the deceleration signal generating circuit (7).

Next, assume that the car is traveling on a road surface with a low coefficient of friction. In this case, the slip signal λ continues for more than 20 seconds, and as a result, the output of the on-off delay timer (9) remains at "°'l".
00@sec is output @1''.

The reference value of the deceleration signal generation circuit (7) is determined by the output 11# of the on-off delay timer (9) to -1 of the smaller one,
Switched to O7. Therefore, when the wheel deceleration exceeds this reference value -1.01, the brake is released, and when it falls below this value, the brake is increased again. Since the road surface has a low coefficient of μ, it is difficult for the wheels to decelerate, but since the reference value is switched to a small value, it is possible to release the brakes at an appropriate time, and also to release the brakes while the deceleration is small. Therefore, the time during which the deceleration is below this reference deceleration can be shortened, and it is possible to prevent the brake from being loosened too much.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the slip reference values in the deceleration signal generation circuit (7) were set to -1, Of and -1, 52, but the slip reference values are not limited to these and may be other values.

Furthermore, a plurality of on/off delay timers may be used to further finely divide the reference values to be switched.

〔Effect of the invention〕

As described above, according to the anti-skid device for a two-wheeled vehicle of the present invention, optimal anti-skid control can be performed no matter how the road surface changes.

[Brief explanation of the drawing]

The figure is a block diagram of an anti-skid device for a motorcycle according to an embodiment of the present invention. In the figure,

Claims (1)

[Claims] A wheel speed detection device that monitors the rotational state of the wheels to detect the wheel speed, a vehicle speed generator that generates an approximate vehicle speed based on the wheel speed, and a difference between the two by comparing the wheel speed and the approximate vehicle speed. a slip detection device that generates a slip signal when the wheel acceleration reaches a predetermined value based on a predetermined relationship; a differentiator that generates a wheel acceleration by differentiating the wheel speed; and a deceleration signal when the wheel acceleration reaches a negative set value. In the anti-skid device for a two-wheeled vehicle, the anti-skid device for a two-wheeled vehicle is equipped with a comparator device that generates a brake pressure in response to generation of the slip signal and deceleration signal, and when the generation of the slip signal continues for a predetermined period of time, the comparison device An anti-skid device for two-wheeled vehicles equipped with a switching device that changes the setting value of the device.