JP2662222B2 - Anti skid brake - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of an anti-skid brake having a function of preventing a tire from slipping or skidding due to braking. (Prior art) If the rotation of the wheel is locked by the brake during braking of the motorcycle, the tire is likely to slip or skid on the track, so braking is performed so that the rotation of the wheel is not completely locked during the brake operation. Brakes provided with an anti-skid mechanism for controlling torque are known (for example, Japanese Patent Application Laid-Open Nos.
No. -110658). (Problems to be Solved by the Invention) However, each of these anti-skid mechanisms controls the hydraulic pressure supplied for braking. Therefore, a pump, a check valve, a relief valve, Many hydraulic devices, such as accumulators, need to be interposed, and undesired factors such as a slight decrease in responsiveness of the braking operation and an increase in the chance of oil leaks compared to brakes without an antilock mechanism are required. Included. SUMMARY OF THE INVENTION An object of the present invention is to provide an anti-skid brake that does not require control of braking hydraulic pressure in order to solve the above-described problems of the conventional brake having an anti-skid mechanism. (Means for Solving the Problems) According to the present invention, a brake disk is rotatably provided with respect to a wheel, the brake disk and the wheel are interconnected via a differential gear, and the relative rotation of the differential gear is used. A driven hydraulic pump is provided, and a solenoid valve is provided to open and close the discharge passage of hydraulic oil from the hydraulic pump. This solenoid valve is normally closed to lock the hydraulic pump, thereby restricting the relative rotation of the differential gear. On the other hand, the relative rotation of the differential gear is allowed by releasing the lock of the hydraulic pump by opening the solenoid valve according to the slip state, so that the transmission of the braking torque between the brake disc and the wheel is cut or reduced. ing. (Operation) In normal braking, the solenoid valve blocks the discharge of hydraulic oil and regulates the operation of the hydraulic pump, thereby preventing the relative rotation of the differential gear, and the brake disc is integrally connected to the wheel. Transmits braking torque. On the other hand, when the rotation of the wheel is locked due to braking and the tire starts to slip, the relative rotation of the differential gear is allowed by opening the solenoid valve and making the pump movable, and the braking torque transmitted from the brake disk to the wheel Is cut or reduced. (Embodiment) FIGS. 1 and 2 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a front wheel of a motorcycle, and 2A and 2B denote brake discs. The brake disc 2A is fixed to the floating piece 5 rotatably supported around the axle 3 via the bearing 4 by bolts 6, and the brake disc 2B is fixed to the center of the side surface of the wheel 1 by bolts 7. 8 is fixed with bolts 9. The side cover 8 is rotatably supported by a hollow shaft 10 fixed around the axle 3 via bearings 11 and 12. Also, a side cover on the opposite side of the wheel 1
13 is fixed by bolts 14 and a floating piece 5 is provided by a bearing 15 interposed inside the side cover 13.
Is rotatably supported on the wheel 1 as well. Axle 3
Protrudes to both sides of the wheel 1 and its protruding ends are supported by front forks 16A and 16B. Front forks 16A and 1
A brake caliper (not shown) for braking the brake discs 2A and 2B is attached to 6B, respectively. A planetary gear 17 as a differential gear and a gear pump 18 are housed inside the side covers 8 and 13 fixed to the side surface of the wheel 1. The planetary gear 17 is constituted by a combination of a sun gear 17A housed in a cylindrical recess 19 formed in the wheel 1 and a planet gear 17B and a ring gear 20 formed on the inner periphery of the recess 19, facing the side cover 13. You. The sun gear 17A is configured to be rotatable via a bearing 21 on the outer periphery of the hollow shaft 10 fixed to the outer periphery of the axle 3. Planet gear 17B is composed of sun gear 17A and ring gear 20.
A planet carrier 23 for supporting the rotating shaft 22 is held between the brake disc 2A and the brake disk 2A together with the floating piece 5.
Fixed through. On the other hand, the gear pump 18 is provided between the planetary gear 17 and the side cover 8. The gear pump 18 is a gear 18A rotatably configured on the outer periphery of the hollow shaft 10 via a bearing 24.
And a gear 18B formed around a shaft 25 parallel to the axle 3. The shaft 25 is rotatably supported by the wheel 1 and the side cover 8 via a bearing 26 while being rotatably supported by a seal 27 via a seal 27. A pump gear 28 that projects into the recess 19 and engages with the sun gear 17A is fixed to the projecting end. A seal is provided between the gear 18A and the sun gear 17A adjacent to the hollow shaft 10.
Cut off at 29. A suction passage 30 and a discharge passage 31 are opened before and after the meshing portion of the gears 18A and 18B, and the gear pump 18 sucks the operating oil of the suction passage 30 into the meshing portion by the rotation of the gears 18A and 18B to the discharge passage 31. Discharge. The discharge passage 31 is connected to the hollow shaft 1 through an annular groove 31A formed in the hollow shaft 10.
Through the inside of 0, it reaches a solenoid valve 32 provided outside the side cover 8. In addition, the suction passage 30 is connected to the downstream side of the solenoid valve 32 via the inside of the hollow shaft 10 via the same annular groove 30A, and communicates with an oil reservoir 33 formed inside the wheel 1. An elastic air chamber 33A for volume compensation is defined in the oil reservoir 33 via a diaphragm. The solenoid valve 32 is attached to the outer periphery of the hollow shaft 10 between the side cover 8 and the front fork 16B, and includes a valve body 35 that shuts off the discharge passage 31 and prevents the gear pump 18 from discharging hydraulic oil. The valve body 35 is supported from behind by a magnetic push rod 36 urged by a relief spring 34. The relieving spring 34 is interposed between a core 37 made of the same magnetic material located behind the push rod 36, and a solenoid 38 housed in a magnetic material case 39 is arranged around the core 37. Is established. The solenoid 38 is connected to a battery mounted on the vehicle via a control circuit by electric wiring (not shown), and when energized by receiving power, the bush rod 36 opposes the relief spring 34 so as to form a closed magnetic circuit around it. Adsorb to the core 37. Although not shown, the control circuit controls the solenoid 38 according to the slip of the front tire detected by comparing the rotation speed of the wheel 1 with the vehicle speed.
It is configured to energize the device. Next, the operation will be described. In the solenoid valve 32 during normal running, the control circuit does not energize the solenoid 38, and the valve body 35 urged by the relief spring 34 closes the discharge passage 31 of the gear pump 18. For this reason, the discharge of the hydraulic oil from the gear pump 18 is locked, and the gear 18A slides on the bearing 24 and rotates with the gear 18B while rotating by rotating the bearing 24 around the hollow shaft 10 integrally with the wheel 1. To maintain a constant relative position.
That is, the gears 18A and 18B rotate around the hollow shaft 10 integrally while engaging the same tooth surface. Further, the pump gear 28 fixed to the same shaft 25 as the gear 18B also does not rotate, and the hollow shaft 10
, And the sun gear 17A meshing therewith is rotated integrally with the wheel 1. Thereby, the planet gear 17B meshing with both the sun gear 17A and the ring gear 20 revolves around the hollow shaft 10 integrally with the wheel 1 without rotating. Therefore, the brake disc 2A and the wheel 1
Are stopped from rotating relative to each other, and when the brake is applied in this state, the braking torque of the brake caliper is immediately transmitted to the wheel 1. That is, in this state, a braking operation similar to that of a normal disc brake having no anti-skid mechanism is performed with good response. On the other hand, when the slip of the tire is detected during braking and the solenoid valve 32 is energized by the control circuit, the excited solenoid 38 attracts the push rod 36 to the core 37 against the relief spring 34. Thus, the discharge passage 31 communicates with the suction passage 30 and the oil reservoir 33, and the relative rotation of the gears 18A and 18B performed while discharging the hydraulic oil to the discharge circuit 31 is free. The hydraulic oil discharged to the discharge circuit 31 by this relative rotation is sucked into the gear pump 18 from the solenoid valve 32 via the suction passage 30, and circulates inside the discharge pump 31 again. The oil reservoir 33 compensates for the pressure fluctuation in the circulating system, and prevents the suction passage 30 from becoming negative pressure, for example, when the solenoid valve 32 is shut off. When the restriction on the relative rotation between the gears 18A and 18B is released, the constraint on the sun gear 17A by the pump gear 28 is released, and the relative rotation between the planet gear 17B and the sun gear 17 becomes possible.
In this state, even if braking torque is applied to the brake disc 2A, the planet gear 17B meshing with the ring gear 20 revolves while rotating the sun gear 17A.
This braking torque is not transmitted to the wheel 1 on the side. Therefore, only the braking torque is transmitted to the wheel 1 via the brake disc 2B fixed to the side cover 8, and as a result, the braking torque acting on the wheel 1 is reduced, so that the tire comes out of the slip state. Start spinning again. The mechanism for transmitting the braking torque described above is schematically shown in FIG. That is, when the braking torque acts on the rotating shaft 22 integral with the brake disc 2A while the ring gear 20 fixed to the wheel 1 is rotating in the direction of the arrow, the planet gear 17B
And the sun gear 17A rotate in the directions of the arrows, respectively, and try to drive the gear pump 18 via the pump gear 28.
At this time, when the solenoid valve 32 is closed as shown in the figure, the rotation of the gear pump 18 is locked, and the braking torque is transmitted to the ring gear 20 (brake disc 2A) as it is.
When the gear 32 is open, the rotation of the gear pump 18 becomes free, so the braking torque drives the gear pump 18 to rotate via the planet gear 17B, the sun gear 17A, and the pump gear 28, and thus the revolution of the planet gear 17B is allowed. Therefore, it is not transmitted to the ring gear 20. Incidentally, the torque for restraining the planet gear 17B during braking depends on the suppression torque generated by the gear pump 18. The braking torque from the disc plate 2A is a gear pump
When the braking torque is larger than the stopping torque for holding the wheel 18 in a stopped state, the brake disc 2A and the wheel 1 rotate relative to each other. Therefore, it is necessary to set the stopping torque generated by the gear pump 18 in accordance with the required braking torque of the disc brake.
Also increases its capacity. However, when the gear pump 18 is driven by increasing the speed by the planetary gear 17 and the pump gear 28 in this way, the stopping torque of the gear pump 18 required to secure the same braking torque must be reduced according to the above-described speed increasing ratio. Therefore, the size of the gear pump 18 can be reduced accordingly. By intermittently connecting the brake caliper 2A and the wheel 1 during braking, the braking torque is optimally adjusted so as not to cause a slip or skid, so that the braking operation is performed without impairing the directional stability, Complete braking efficiently with distance. Although this embodiment is directed to a double caliper, the present invention is sufficiently applicable to a single caliper motorcycle using only the brake caliper 2A. (Effects of the Invention) As described above, the present invention includes a hydraulic pump driven by the relative rotation of the differential gear by coupling the brake disc and the wheel via the differential gear, and The solenoid valve that opens and closes the hydraulic oil discharge passage is normally provided, so the relative rotation of the differential gear is regulated by closing the solenoid valve and locking the hydraulic pump, and the braking torque from the brake disc side is transmitted to the wheel side. While transmitting immediately, the solenoid valve is opened according to the slip state to unlock the hydraulic pump, thereby permitting the relative rotation of the differential gear and cutting or reducing the transmission of the braking torque between the brake disc and the wheel. be able to. Therefore, tire slip and skid due to braking are suppressed, directional stability during braking is improved, and the braking distance is shortened. Further, in the normal braking operation, the transmission of the braking torque between the brake disc and the wheel is performed through the gear whose relative rotation is locked, so that the transmission loss of the braking torque is small, and a special driving system for the brake caliper is used. Since there is no need to intervene devices, the responsiveness of the braking operation is good. For this reason, according to the present invention, it is possible to provide a good anti-skid function without impairing the reliability of the braking force and responsiveness of the brake at all.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a center portion of a wheel showing an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining a mechanism of transmitting a braking torque. 1… wheel, 2A, 2B …… brake disc, 17…
Planet gears, 17A …… Sun gears, 17B …… Planet gears,
18 ... gear pump, 31 ... discharge passage, 32 ... solenoid valve.

Claims (1)

(57) [Claims] A brake disk is rotatably provided with respect to the wheel, a brake disk is connected to the wheel via a differential gear, and a hydraulic pump driven by the relative rotation of the differential gear is provided. A solenoid valve for opening and closing the discharge passage is provided, and the relative rotation of the differential gear is regulated by normally closing the solenoid valve and locking the hydraulic pump, while opening the solenoid valve according to the slip state. An anti-skid brake, wherein the hydraulic pump is unlocked to permit relative rotation of the differential gear and cut or reduce transmission of braking torque between the brake disc and the wheel.