JP3914000B2 - Anti-lock brake control method for motorcycles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention calculates the acceleration / deceleration of front wheels and rear wheels based on the wheel speeds detected by the front wheel and rear wheel wheel speed sensors, respectively, and the calculated acceleration / deceleration has changed from positive to negative. Thus, the present invention relates to an antilock brake control method for a motorcycle that can execute antilock control of front and rear wheel brakes independently of each other by starting pressure increase control.
[0002]
[Prior art]
Such an antilock brake control method for a motorcycle is already well known, for example, in Japanese Patent Laid-Open No. 9-328065.
[0003]
[Problems to be solved by the invention]
By the way, when anti-locking control of front wheel brakes in motorcycles, considering the road surface with a low coefficient of friction in order to improve vehicle stability, set a large amount of pressure reduction during decompression control of front wheel brakes. It is common to do. However, although it is possible to travel, it tends to be over-depressurized while traveling on a road surface with a low friction coefficient (for example, μ = 0.4). A “feeling of falling out” may occur in the deceleration, and the braking feeling may deteriorate.
[0004]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an antilock brake control method for a motorcycle with improved braking feeling during single braking of a front wheel traveling on a road surface having a low friction coefficient. And
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention calculates acceleration / deceleration of front wheels and rear wheels based on wheel speeds detected by a wheel speed sensor for front wheels and rear wheels, and calculates and accelerates them. Anti-lock brake control for motorcycles that can perform anti-lock control for wheel brakes for front wheels and rear wheels independently of each other by starting pressure-increasing control with the change from positive to negative In the method, when the anti-lock control of the front wheel brake is performed on the road surface having a low friction coefficient, the front wheel has a calculated acceleration / deceleration that is a positive value set in advance with respect to the calculated acceleration / deceleration . after exceeding the set acceleration and deceleration, the differential value of the front wheel of the operation acceleration and deceleration, and the front wheel slip becomes a preset range below a predetermined set differential value relates differential values of the calculated acceleration and deceleration Rate set When equal to or less than the slip ratio is characterized in that Gosuru pressure increasing the fluid pressure in the front wheel brake even before the front wheels of the operational acceleration and deceleration is converted from positive to negative.
[0006]
According to such a control method, when performing antilock control of the front wheel brake in the single brake state of the front wheel, the front wheel brake is prevented from being over-depressurized on the road surface with a low friction coefficient, The braking feeling can be improved by avoiding the occurrence of “missing feeling” in the deceleration. In other words, the differential value of the calculated acceleration / deceleration of the front wheels indicates the tendency of the calculated acceleration / deceleration of the front wheels to change. The wheel speed of the front wheel should recover relatively quickly by taking into account the pressure reduction control of the front wheel brake. Therefore, after detecting a relatively fast wheel speed return by the calculated acceleration / deceleration of the front wheels exceeding the positive set acceleration / deceleration, the calculation of the front wheels is calculated / decelerated. When the differential value of the front wheel brake is less than a predetermined differential value, and the slip ratio of the front wheel is sufficiently reduced in that state, the pressure control of the front wheel brake is started. Since the state occurs before the calculated acceleration / deceleration of the front wheels changes from positive to negative, the front wheel brake can be brought into a pressure increasing state early.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0008]
1 and 2 show an embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a motorcycle brake device, and FIG. 2 is a timing chart.
[0009]
First, in FIG. 1, a scooter type motorcycle includes a first master cylinder MA that outputs a hydraulic pressure in response to an operation of a right brake lever 1 that is operated by an occupant with a right hand, and a left brake lever that is operated by an occupant with a left hand. The second master cylinder MB that outputs the hydraulic pressure in response to the operation of 2 is mounted. On the other hand, a front wheel brake BF having a pair of pods 3 and 4 is mounted on the front wheel of the motorcycle, and the first master cylinder MA is connected to the front wheel brake BF via the control valve means 6A. The second master cylinder MB is connected via the control valve means 6B1 and the delay valve 5 while being connected. The second master cylinder MB is connected to the rear wheel brake BR mounted on the rear wheel via the control valve means 6B2.
[0010]
The control valve means 6A includes a normally open solenoid valve 7 provided between the pod 3 of the front wheel brake BF and the first master cylinder MA, a check valve 8 connected in parallel to the normally open solenoid valve 7, It is composed of a normally closed electromagnetic valve 9 provided between the pod 3 of the front wheel brake BF and the reservoir 10A. The communication between the first master cylinder MA and the pod 3 of the front wheel brake BF is interrupted. The communication between the pod 3 of the front wheel brake BF and the reservoir 10A can be switched.
[0011]
A suction side of a return pump 11A that pumps up the brake fluid of the reservoir 10A and pumps it to the first master cylinder MA side is connected to the reservoir 10A via a suction valve 12A. The discharge side of the return pump 11A is It is connected to the first master cylinder MA via the discharge valve 13A.
[0012]
The control valve means 6B1, like the control valve means 6A, is composed of a normally open solenoid valve 7, a check valve 8, and a normally closed solenoid valve 9, and is connected to the pod 4 of the front wheel brake BF. It is possible to switch between communication / blocking between the delay valve 5 and the second master cylinder MB and communication / blocking between the delay valve 5 and the reservoir 10B.
[0013]
Similarly to the control valve means 6A, 6B1, the control valve means 6B2 is composed of a normally open type electromagnetic valve 7, a check valve 8 and a normally closed type electromagnetic valve 9. The communication / blocking between the two master cylinders MB and the communication / blocking between the rear wheel brake BR and the reservoir 10B can be switched.
[0014]
A suction side of a return pump 11B that pumps up the brake fluid of the reservoir 10B and pumps it to the second master cylinder MB side is connected to the reservoir 10B via a suction valve 12B. The discharge side of the return pump 11B is It is connected to the second master cylinder MB via the discharge valve 13B.
[0015]
A common single motor 16 is connected to the both return pumps 11A and 11B, and the both return pumps 11A and 11B are driven by the motor 16.
[0016]
In such control valve means 6A, 6B1, 6B2, during the anti-lock brake control when the wheel is about to enter the locked state when the right and left brake levers 1, 2 are operated, the normally open solenoid valve 7. The normally open solenoid valve corresponding to the wheel that is likely to enter the locked state is closed by energization, and the normally closed solenoid valve corresponding to the wheel of the normally closed solenoid valve 9 is opened by energization. . Then, a part of the brake fluid pressure is released to the reservoir 10A or 10B and is reduced. In order to maintain the brake fluid pressure, the normally open solenoid valve 7... May be closed by energization and the normally closed solenoid valve 9. When pressure is applied, the normally open solenoid valves 7 are opened by de-energization and the normally closed solenoid valves 9 are kept closed by de-energization.
[0017]
The motor 16 that drives the pair of return pumps 11A and 11B in common starts operation in response to the start of the antilock brake control, and the brake fluid released to the reservoirs 10A and 10B is returned to the return pumps 11A and 11B. 11B is returned to the first and second master cylinders MA and MB. Accordingly, the amount of operation of the brake levers 1 and 2 in the first and second master cylinders MA and MB does not increase by the amount released to the reservoirs 10A and 10B.
[0018]
The deenergization / energization of the normally open solenoid valve 7... And the normally closed solenoid valve 9... And the operation of the motor 16 in each control valve means 6A, 6B1, 6B2 individually detect the wheel speeds of the front wheels and the rear wheels. It is controlled by a control unit 18 to which detection signals of front wheel and rear wheel wheel speed sensors 19F and 19R are inputted. The control unit 18 detects the wheels based on the detection signals of the wheel speed sensors 19F and 19R. When it is determined that the vehicle is about to enter the locked state, the operation of each control valve means 6A, 6B1, 6B2 is controlled so as to repeat the brake fluid pressure decreasing / increasing cycle, so that the wheel brakes for the front and rear wheels are controlled. Anti-lock control of BF and BR is executed.
[0019]
The control unit 18 starts the operation of the motor 16 with the start of antilock brake control by any one of the control valve means 6A, 6B1, 6B2.
[0020]
By the way, the control unit 18 calculates acceleration / deceleration of the front wheels and the rear wheels based on the wheel speeds detected by the front wheel and rear wheel wheel speed sensors 19F and 19R, respectively. The pressure increase control starts when the deceleration changes from positive to negative, but the friction coefficient μ of the running road surface is about 0.4, that is, the low friction coefficient that enables the motorcycle to run. During anti-lock control of the front wheel brake BF with front wheel single braking on the road surface, the front wheel calculated acceleration / deceleration ACL exceeds the positive set acceleration / deceleration ACLO before the front wheel calculated acceleration / deceleration ACLO. When the front wheel slip rate falls below the set slip rate within a range where the ACL differential value WDD is less than the predetermined set differential value WDDO, even before the front wheel calculation acceleration / deceleration ACL changes from positive to negative. So that Gosuru the pressure increase control the hydraulic pressure in the wheel brake BF.
[0021]
Next, the operation of this embodiment will be described. The front wheel brake BF is used to prevent the front wheels from being locked when the front wheels are individually braked on a road surface having a low friction coefficient that allows the motorcycle to travel. When the anti-lock control is executed, when the front wheel speed, the front wheel calculation acceleration / deceleration ACL, and the front wheel calculation acceleration / deceleration ACL differential value WDD change as shown in FIG. In this case, the pressure increase control of the front wheel brake BF is started at time t4 when the front wheel calculation acceleration / deceleration ACL changes from positive to negative. The front wheel at time t3 within a range where the differential value WDD of the calculated acceleration / deceleration ACL of the front wheel is less than the set differential value WDDO at time t2 after the deceleration ACL exceeds the positive set acceleration / deceleration ACLO at time t1. Slip There when it becomes less than the set slip rate, i.e. at time t3 when the wheel speed of the front wheels is equal to or greater than the reference wheel speed setting slip ratio starts to pressure increasing control of the front wheel brake BF.
[0022]
In this way, the front wheel brake BF is in an over-depressurized state by determining the start-up control start timing of the front wheel brake BF when the front wheels are individually braked on a road surface having a low friction coefficient that allows the motorcycle to run. Thus, the braking feeling can be improved by avoiding the occurrence of “missing feeling” in the deceleration.
[0023]
That is, the differential value WDD of the front wheel arithmetic acceleration / deceleration ACL indicates a change tendency of the front wheel arithmetic acceleration / deceleration ACL, and the low friction coefficient that is difficult to travel on a road surface that can travel but has a low friction coefficient. By reducing the pressure of the front wheel brake BF in consideration of the road surface, the front wheel speed should recover relatively quickly. Therefore, after detecting a relatively fast wheel speed return when the front wheel calculation acceleration / deceleration ACL exceeds the positive setting acceleration / deceleration ACLO, the front wheel calculation acceleration / Detection is performed when the differential value WDD of the deceleration ACL is less than a predetermined set differential value WDDO, and pressure increase control of the front wheel brake BF is started in response to a sufficient decrease in the slip ratio of the front wheels. This state occurs before the front wheel calculation acceleration / deceleration ACL changes from positive to negative, so that the front wheel brake BF can be brought into a pressure increasing state early.
[0024]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.
[0025]
【The invention's effect】
As described above, according to the present invention, when the anti-lock control of the front wheel brake is executed in the single brake state of the front wheel , the front wheel brake is prevented from being over-depressurized on the road surface having a low friction coefficient. Further, it is possible to improve the braking feeling by avoiding a “feeling of falling out” in the deceleration. In other words, the differential value of the calculated acceleration / deceleration of the front wheels indicates the changing tendency of the calculated acceleration / deceleration of the front wheels, and the road surface with a low friction coefficient that is difficult to drive on a road surface that can travel but has a low friction coefficient. By reducing the pressure of the front wheel brake in consideration of the above, the front wheel speed should recover relatively quickly. Therefore, after detecting a relatively fast wheel speed recovery by the front wheel calculation acceleration / deceleration exceeding the preset positive acceleration / deceleration, the front wheel changes gradually. This is detected when the differential value of the calculated acceleration / deceleration is less than the preset differential value set in advance, and the front wheel brake increases in response to the sufficiently reduced slip ratio of the front wheels in that state. The control is started, and this state occurs before the front wheel calculation acceleration / deceleration changes from positive to negative. Even when the road surface has a coefficient of friction, it is possible to avoid the occurrence of “feeling of slipping” in the deceleration and improve the braking feeling.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a motorcycle brake device.
FIG. 2 is a timing chart.
[Explanation of symbols]
19F: front wheel speed sensor 19R: rear wheel speed sensor ACL: front wheel calculation acceleration / deceleration ACLO ... positive setting acceleration / deceleration BF ... front wheel brake BR・ ・ ・ ・ Rear wheel brake WDD ・ ・ ・ Calculation acceleration / deceleration differential value WDDO of front wheel ・ ・ Predetermined set differential value

Claims (1)

The acceleration / deceleration of the front and rear wheels is calculated based on the wheel speed detected by the front wheel and rear wheel speed sensors (19F, 19R), respectively, and the calculated acceleration / deceleration changes from positive to negative. Thus, in the antilock brake control method for a motorcycle, the antilock control for the front wheel and rear wheel brakes (BF, BR) can be executed independently of each other by starting the pressure increase control. ,
During antilock control of the front wheel brake (BF) in the state where the front wheel single brake is executed on the road surface with a low friction coefficient, the calculated acceleration / deceleration (ACL) of the front wheel is related to the calculated acceleration / deceleration (ACL). After the preset positive set acceleration / deceleration (ACLO) is exceeded, the differential value (WDD) of the calculated acceleration / deceleration (ACL) of the front wheel is the differential value of the calculated acceleration / deceleration (ACL) ( When the front wheel slip ratio falls below the preset slip ratio when the range is less than the preset preset differential value (WDDO) for WDD) , the front wheel calculation acceleration / deceleration (ACL) changes from positive to negative. An anti-lock brake control method for a motorcycle, characterized in that the hydraulic pressure of the front wheel brake (BF) is increased even before starting.

Images