JPS6220956B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a braking device for a motorcycle that is equipped with independently operated brake levers and brake pedals, and is capable of approximating the braking force of front and rear wheels to an ideal distribution curve. In addition, under driving conditions that require only rear wheel braking, such as when driving at slow speeds, on rough roads, or when driving down steep slopes, only the rear wheel disc brake can be activated as necessary. It is an object of the present invention to provide the above-mentioned braking device.

In order to achieve the above object, the present invention provides a hydraulic cylinder for operating a front wheel disc brake and a hydraulic cylinder for operating a rear wheel disc brake, which are connected to the output port of a front master cylinder operated by a brake lever through first and second oil passages, respectively. and connected to the second oil passage, a pressure reducing valve capable of reducing the output oil pressure and transmitting it to the rear wheel disc brake operating hydraulic cylinder when the output oil pressure of the output port increases to a predetermined value or more. Furthermore, the rear wheel disc brake is provided with a mechanical actuation mechanism that can be operated at any time even when the hydraulic cylinder for actuating the rear wheel disk brake is not actuated, and this actuation mechanism and the brake pedal are connected mechanically. It is characterized by being linked to each other.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 1, M is a known front master cylinder that is installed in a handle pipe 1 of a motorcycle and manually operated by a brake lever 2, and its output port P The output oil path L connected to the pressure reducing valve V branches into two systems, the first and second oil paths L ₁ and L ₂ , and the first oil path L ₁ is connected to the hydraulic cylinder for operating the front wheel disc brake Bf. (not shown), and the second oil passage _L2 is connected to a hydraulic cylinder 21 (see FIG. 2) for operating the rear wheel disc brake Br. Df and Dr are brake discs of front and rear wheel disc brakes Bf and Br, respectively.

As shown in Fig. 3, the pressure reducing valve V proportionally reduces the output hydraulic pressure of the front master cylinder M and transmits it to the rear wheel disc brake Br, and is equipped with a valve case 3 fixed to a suitable position on the vehicle body. Outside of that,
The inlet 4 connected to the output oil passage L and the first and second outlets 5 ₁ and 5 ₂ connected to the first and second oil passages L ₁ and L ₂ , respectively, are opened. Further, an input hydraulic chamber 6 is formed in the valve case 3 to communicate the inlet 4 with the first and second outlets 5 ₁ , 5 ₂ , and an output hydraulic chamber 7 is formed on the second outlet 5 ₂ side. Ru. An elastic valve seat 8 made of rubber or the like is installed between the two hydraulic chambers 6 and 7, and a valve body 9 that cooperates with the valve seat 8 to communicate and cut off communication between the two hydraulic chambers 6 and 7 is installed on the valve seat 8. is placed through the The valve body 9 has a piston-like valve part 9b that cooperates with the valve seat 8 and a guide shaft 9c that projects from its outer end surface integrally formed at the tip of a valve rod 9a. Bearing 10 forming the outer end wall of chamber 6
is slidably supported via a seal member 11,
Further, the valve portion 9b and the protruding shaft 9c are arranged in the output hydraulic pressure chamber 7, and the protruding shaft 9c is loosely fitted into a bearing hole 12 that opens into the output hydraulic pressure chamber 7. The bearing hole 12 prevents the valve body 9 from tilting, and the opening limit of the valve rod 9 is regulated by the wall surface of the output hydraulic chamber 7. Between the seat plate 13 fixed to the tip of the valve rod 9a and the seat plate 14 supported on the inner end of the bearing 10, the valve part 9b is urged in a direction to separate it from the valve seat 8, in the illustrated example upward. Spring 1
5 will be reduced.

As shown in FIG. 2, the rear wheel disc brake Br includes a brake caliper 16 having a pair of left and right arms 16 ₁ and 16 ₂ that straddle the brake disc Dr.
It is slidably supported via a dustproof boot _B1 on a sleeve 19 fitted onto a support bolt 18 of No.7.
As shown in Fig. 1, the bracket 17 is fixed to the rear axle supported by the rear fork Fr with a bolt 20, and the bracket 17 and the rear fork Fr
A torque rod R for preventing rotation of the bracket 17 is attached between the bracket 17 and the bracket 17.

A hydraulic cylinder 21 connected to the second oil passage L ₂ is formed inside the right arm body ₁₆₂ , and a cup-shaped actuating piston 22 is slidably fitted inside the cylinder 21 via a seal member 23. A base plate 24a of a movable brake pad 24 is fixed to the open end surface of the actuating piston 22, and a friction member 24 is bonded to the base plate 24a.
b faces one side of the brake disc Dr.
On the other hand, a base plate 25a of a fixed brake pad 25 is fixed to the inner surface of the left arm body ₁₆₁ .
A friction member 25b bonded to 5a faces the other side of the brake disc Dr.

On the outside of the right arm body ₁₆₂ , a female threaded member 26, which was enclosed during casting, opens, and a male threaded member 27 is screwed into the threaded hole from the outside. These screw members 2
The threads 6 and 27 are formed as multistart left-handed threads with a coarse lead, so that the male threaded member 27 undergoes a relatively large axial displacement with a small rotation angle.

A square shaft 27a is integrally formed at the outer end of the male threaded member 27, and a flange 27b is integrally formed at the base end thereof, and the lower end of the operating lever 28 is fitted and attached to the square shaft 27a. The tip of the operating lever 28 is connected to a brake pedal 30 via a guide wire (or rod) 29, as shown in FIG.

A large end 31a of an operating rod 31 that advances the movable brake pad 24 independently of the operating piston 22 is slid into the operating piston 22 via a seal member 32, and its end surface is connected to the base plate 2 of the movable brake pad 24.
Face 4a. The shaft portion 31b of the actuating rod 31 is slidably fitted into the bottom of the actuating piston 22 and through holes 33, 34 in the cylinder wall via seal members 35, 36, respectively, and its end surface is fitted with an adjusting bolt 37 screwed into a male threaded member 27. Abuts on the inner edge. The adjustment bolt 37 is used to adjust the gap between the movable brake pad 24 and the brake disc Dr via the operating rod 31, and is fixed to the male threaded member 27 by a lock nut 38 after adjustment. B ₂ and B ₃ are dustproof boots.

According to the present invention, the operating rod 31, the adjusting bolt 37, the male threaded member 27, and the operating lever 28 cooperate with each other to operate the rear wheel disc brake Br at any time even when the hydraulic cylinder 21 is not operating. It constitutes a mechanical actuation mechanism S.

The front wheel disc brake Bf is a known caliper sliding type that is attached to the front fork Ff and is equipped with a brake caliper, a hydraulic cylinder, an operating piston, and fixed and movable brake pads that are substantially similar to the rear wheel disc brake Br. Therefore, detailed configuration will be omitted.

Next, to explain the function of this embodiment, when driving on a normal road surface, the front and rear wheel disc brakes Bf, Br
When braking is performed by operating the brake lever 2, the front master cylinder M is operated by manually operating the brake lever 2, and hydraulic pressure is output from the output port P thereof. The output oil pressure is output oil path L, pressure reducing valve V
The hydraulic pressure is transmitted to the front wheel disc brake Bf through the input hydraulic chamber 6 and the first oil passage _L1 , and from the hydraulic chamber 6 to the rear wheel disc brake Br through the output hydraulic chamber 7 and the second oil passage _L2 communicating therewith. and operate them.

In the rear wheel disc brake Br, the operating piston 22 moves forward due to the output oil pressure, the movable brake pad 24 is pressed against one side of the brake disc Dr, and the reaction force causes the brake caliper 16 to move the sleeve 19 to the right in FIG. The fixed brake pad 25 is pressed against the other side of the brake disc Dr, and braking of the rear wheel is started. A similar operation is performed for the front wheel disc brake Bf, and the front and rear wheel disc brakes Bf,
The working oil pressure of Br increases equally as shown by the line segment OA of the distribution line W in FIG.

When the working oil pressure of the front and rear wheel disc brakes Bf, Br reaches point A in Figure 4 due to an increase in the output oil pressure of the output port P of the front master cylinder M, the working oil pressure of the rear wheel disc brake Br is activated by the pressure reducing valve V. Next, we will explain its effects.

First, when the hydraulic pressure in the input and output hydraulic chambers 6 and 7 rises to correspond to point A in Figure 4 due to an increase in the output hydraulic pressure at the output port P, a downward pressing force is generated in Figure 3 due to the hydraulic pressure acting on the valve body 9. (corresponds to the cross-sectional area S ₁ of the base of the valve rod 9a multiplied by the hydraulic pressure of the output hydraulic chambers 6 and 7) is applied to the biasing force of the spring 15 on the valve body 9 (the set load of the spring 15). Then, the valve body 9 is moved downward in FIG. 3, and its valve portion 9b is seated on the valve seat 8, and the communication between the output hydraulic chambers 6 and 7 is cut off. After that, if the output oil pressure of the output port P further increases, the upward pressing force of the valve body 9 due to the oil pressure of the input oil pressure chamber 6 (the cross-sectional area S ₂ of the valve portion 9b and the cross-sectional area
This approximately corresponds to the difference from _S1 multiplied by the oil pressure of the input oil pressure chamber 6. ) overcomes the downward pressing force of the valve body 9 due to the hydraulic pressure of the output hydraulic chamber 7 (approximately equivalent to the cross-sectional area S ₂ multiplied by the hydraulic pressure of the output hydraulic chamber 7) and pushes the valve body 9 upward. This pushes back the valve part 9b away from the valve seat 8 and communicates between the two hydraulic chambers 6 and 7 again, increasing the pressure in the output hydraulic chamber 7. However, as the pressure increases, the pressure in the valve body 9 due to the hydraulic pressure in the output hydraulic chamber 7 increases. The downward pressing force immediately increases and the valve body 9 is moved downward again to cut off the communication between the two hydraulic chambers 6 and 7, and from then on, the output port P
The same operation is repeated as the output oil pressure increases,
As a result, the output hydraulic pressure of the output port P can be proportionally reduced and transmitted to the rear wheel disc brake Br as shown by the line AB in FIG. 4.

Therefore, the locking phenomenon of the rear wheels due to the decrease in rear wheel load accompanying the braking effect is prevented, and the braking force for the front and rear wheels that approximates the ideal distribution curve X in FIG. 4 is obtained.
The vehicle can be stopped reliably. Figure 4 Y
is the actual distribution line when no pressure reducing valve is provided, and Z is the limit lock line of the road surface friction coefficient μ (μ=1).

The pressure at which the pressure reducing valve V starts reducing pressure is determined by the cross-sectional area S ₁ and the biasing force of the spring 15 on the valve body 9, and the pressure reducing ratio is determined by the cross-sectional area (S ₂ - _{S 1} ) and the cross-sectional area S ₁ . approximately determined by the ratio.

When driving on rough roads such as gravel roads or uneven roads where the front wheels tend to skid, or when driving down steep slopes and only rear wheel braking is required, depress the brake pedal 30 and the pedal force will be transferred to the wire. 29 to the operating lever 28, and the operating lever 28 rotates counterclockwise in FIG. As a result, the male threaded member 27 moves forward, so the operating rod 31 also moves forward via the adjustment bolt 37, and the movable brake pad 24 is pressed against one side of the brake disc Dr, and the reaction force causes the brake caliper 16 to move forward in the same manner as described above. 2, the fixed brake pad 25 is pressed against the other side of the brake disc Dr, and braking is applied to the rear wheel.

If the rear wheel braking described above is applied even when the vehicle is running at very low speeds, it is possible to use both driving and braking to achieve stable running without wobbling.

As described above, according to the present invention, the front wheel disc brake operating hydraulic cylinder and the rear wheel disc brake operating hydraulic cylinder 21 are connected to the output port P of the front master cylinder M operated by the brake lever 2 as the first and second hydraulic cylinders, respectively. 2 oil road
L ₁ and L ₂ are connected to the second oil passage L ₂ , and when the output oil pressure of the output port P rises above a predetermined value, the output oil pressure is reduced and the oil pressure for operating the rear wheel disc brake is supplied. Since a pressure reducing valve V that can be transmitted to the cylinder 21 is installed, the braking hydraulic pressure can be ideally distributed to the front and rear disc brakes Br and Bf by simply manually operating the brake lever 2, and the braking effect of these brakes is Therefore, it is possible to prevent the occurrence of locking of the rear wheels due to a reduction in the rear wheel load, and it is possible to contribute to improving the braking efficiency as a whole.

In addition, the rear wheel disc brake Br is connected to the hydraulic cylinder 21 for operating the rear wheel disc brake.
A mechanical actuation mechanism S that can be activated at any time even when the brake pedal is not in operation is attached, and this actuation mechanism S and the brake pedal 30 are mechanically linked, so that when running at a slow speed,
When driving on rough roads or down steep slopes, etc.
Under driving conditions that require only rear wheel braking, only the rear wheel disc brake Br can be operated accurately by simply pressing the brake pedal 30, and since the rear wheel braking is performed mechanically, It is possible to brake and stop for a long time without relying on hydraulic pressure, and there is no need to worry about oil leakage. In addition, there is no need to specially install expensive hydraulic piping on the brake pedal 30 side, that is, it is sufficient to install only one master cylinder M on the brake lever 2 side, so the overall configuration of the hydraulic circuit is simple and can contribute to cost reduction. . Furthermore, even if a failure of hydraulic fluid should occur in the brake hydraulic system, the rear wheel disc brake Br can be effectively operated by mechanical operation using the brake pedal 30.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, in which Fig. 1 is an overall schematic diagram, Fig. 2 is a vertical cross-sectional view of the rear wheel disc brake, Fig. 3 is a longitudinal cross-sectional view of the pressure reducing valve, and Fig. 4 is a front view. , is a graph showing changes in rear wheel disc brake operating pressure. Bf...Front wheel disc brake, Br...Rear wheel disc brake, _L1 ...1st oil passage, _L2 ...2nd
Oil passage, M...front master cylinder, P...output port, V...pressure reducing valve, S...operating mechanism, 2...
...brake lever, 30...brake pedal.

Claims (1)

[Claims] 1. A front wheel disc brake operating hydraulic cylinder and a rear wheel disc brake operating hydraulic cylinder 21 are connected to the output port P of the front master cylinder M operated by the brake lever 2 through first and second oil passages L ₁ and L ₂ , respectively. is connected to the second oil path _L2 , and when the output oil pressure of the output port P rises to a predetermined value or more, the output oil pressure is reduced and transmitted to the rear wheel disc brake operating hydraulic cylinder 21. A pressure reducing valve V is installed, and the rear wheel disc brake Br is further provided with a mechanical actuating mechanism S that can be operated at any time even when the rear wheel disc brake actuating hydraulic cylinder 21 is not in operation. A braking device for a motorcycle that mechanically interlocks a mechanism S and a brake pedal 30.