JPS633799B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device for a motorcycle.

Generally, when braking a car suddenly, in order to prevent unstable behavior due to wheel lock, the system detects wheel lock due to excessive braking or signs thereof and weakens the braking force.
Various devices have been developed to prevent or release wheel locks, so-called anti-skid devices. In such a device, once wheel lock is detected, the brake input may further increase during the time delay from the actual excessive braking start point to the lock detection and brake input adjustment. With this in mind, the braking input was reduced by several tens of percent in one fell swoop to alleviate the braking force. Therefore, in a normal case, that is, when the braking input does not increase much, the braking force will temporarily drop to a value that is considerably lower than the braking force that should originally be obtained, that is, the maximum braking force that will not cause the wheels to lock.

By the way, as shown in FIG. 1, a conventional brake system for a motorcycle has a front wheel brake system 1.
and a rear wheel brake system 2 are provided independently, and the driver performs braking by using both brake systems 1 and 2 in combination at an appropriate ratio. In addition, in the case of a two-wheeled vehicle, even if the rear wheel locks, you can avoid the risk of falling by operating the steering wheel, whereas if the front wheel locks, it will immediately lead to a fall.
The aforementioned anti-skid device 3 is connected to the front wheel brake system 1.
Various studies are being conducted on installing the but,
When the anti-skid device 3 is activated, the braking force of the front wheel brake system 1 is suddenly reduced, and although the vehicle is prevented from falling over, there is a problem in that the braking and stopping distance becomes longer.

In addition, when the anti-skid device 3 as described above is installed, the following two measures should be taken in case of failure of the device.
Two methods are possible. That is, the first method is a method in which the braking function of the front wheel brake 4 is lost when the anti-skid device 3 fails, and braking is performed solely by the rear wheel brake 5. This method is not a desirable method because the braking distance becomes very long. The second method, contrary to the above, is a method in which the braking function of the front wheel brake 4 is not lost even if the anti-skid device 3 fails. In this case, there is no problem like the above problem of longer braking distance, but if the driver does not notice the failure of the anti-skid device 3, the driver will strongly brake the front wheel brakes 4 in anticipation of the anti-skid device 3 working. In this case, if the device 3 is out of order, there is a risk that the front wheels will be overbraked, leading to a front wheel lock condition.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a brake device for a motorcycle equipped with an anti-skid device that solves the above-mentioned problems. Embodiments of the present invention will be described below based on FIGS. 2 and 3.

As shown in FIG. 2, the brake system of the present invention includes a first brake system 12 that brakes the front wheels 10 and rear wheels 11 simultaneously, and a second brake system 13 that brakes only the front wheels 10. The first brake system 12 includes a brake pedal 14 and a master cylinder 1.
5. Front wheel 1st brake system 16, Rear wheel brake 1
7. Consists of a hydraulic pressure adjustment valve 18 provided in the middle of the oil path of the rear wheel brake 17. The brake force distribution in the first brake system 12 is such that the effect of the rear wheel brake 17 is sufficiently greater than the ideal brake force distribution curve b, as shown by the curve a in FIG. 3, due to the action of the hydraulic pressure regulating valve 18. It is set as follows. The above curve a
A corner point c in FIG. 1 indicates the starting point of the proportional pressure reduction action of the oil pressure regulating valve 18.

On the other hand, the second brake system 13 includes a brake lever 19 on the handlebar, a master cylinder 20, and a second brake lever on the front wheel.
It consists of a brake 21 and an anti-skid device 22 provided in the middle of the oil path of the front second brake 21.

In FIG. 3, the limit line at which the front wheels are locked under a certain road surface condition is represented by d, but now suppose that a braking force exceeding the front wheel lock limit is applied, as represented by point p, and the anti-skid device is activated. In this case, the braking force in the case where the front and rear wheel brake systems 1 and 2 are independent as shown in FIG.
and the front wheel brake force QP, and the front wheel brake force is increased by the operation of the anti-skid device 3.
For example, 50% of QP will be removed.

On the other hand, the braking force in the brake system of the present invention shown in FIG. 2nd brake system 13
For example, 50% of the brake force RP will be released. Comparing this with the brake system shown in FIG. 1, the magnitude of the brake force released is clearly smaller, and therefore the braking stopping distance is shorter.

Further, an on-off valve 23 is provided in the second brake system 13, and a failure of the anti-skid device 22 is detected by, for example, a self-diagnosis device 24, and the on-off valve 23 is closed by the self-diagnosis device 24, thereby controlling the braking function of the second brake system 13. By losing it, it is possible to prevent the front wheels from locking even when the anti-skid device 22 fails, and to obtain a relatively large braking effect using the remaining first brake system 12.

For example, if the rear wheel lock limit line in the same road surface condition as the front wheel lock limit line is represented by a is represented by e, the braking function of the front wheel brake system 1 of the brake system shown in FIG. 1 will be lost in the same way as above. In this case, the maximum braking force applied only by the rear wheel brake system 2 will be OS, but in the brake system of this invention shown in FIG. 2, the maximum braking force applied only by the first brake system 12 will be OU + UT,
A much greater braking effect can be obtained.

In the case of FIG. 2, a function may be added to increase the volume of the oil passage between the on-off valve 23 and the second brake 21 at the same time as the on-off valve 23 is closed. Also,
The means for losing the braking function of the second brake system 13 when the anti-skid device 22 fails is not limited to electrical methods, but in purely mechanical anti-skid devices, a purely mechanical method depending on the principle and structure of the anti-skid device can be adopted. be done.

As mentioned above, the first claim of this application
The inventions described in the second and second embodiments exhibit the common effect of being able to minimize an increase in braking distance due to the operation of a so-called anti-skid device in a brake device for a motorcycle. In addition, the invention stated in the second item of the same is:
Even if the brake function of the second brake system to which the anti-skid device belongs is lost in order to prevent the front wheels from locking when the anti-skid device malfunctions, the front and rear wheels are simultaneously braked by the first brake system, and the brakes are sufficiently applied to the rear. Therefore, it is possible to brake within a short braking distance and without the risk of locking the front wheels.

[Brief explanation of the drawing]

FIG. 1 is a simplified diagram of a conventional brake device, FIG. 2 is a simplified diagram of a brake device of the present invention, and FIG. 3 is a brake force distribution curve diagram. 12...First brake system, 13...Second brake system, 16...Front wheel first brake, 17...Rear wheel brake, 18...Hydraulic pressure adjustment valve, 21...Front wheel second brake, 22...Anti skid device, 23
...Open/close valve.

Claims (1)

[Claims] 1. A first brake system that simultaneously brakes the front and rear wheels;
A second brake system is provided that brakes only the front wheels, and the first
A brake for a motorcycle, characterized in that the brake force distribution between the front and rear wheels of the brake system is set to be sufficiently rearward, and the second brake system is provided with a device that detects excessive braking of the front wheels and reduces the braking effect. Device. 2. A first brake system that brakes the front and rear wheels simultaneously;
A second brake system is provided that brakes only the front wheels, and the first
The brake force distribution between the front and rear wheels of the brake system is set to be sufficiently rearward, and the second brake system is equipped with a device that detects excessive braking of the front wheels and reduces the braking effect, and when the device fails, the second brake is activated. A braking device for a motorcycle, characterized by being provided with a mechanism that causes the system to lose its braking function.