JPS6213893Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a master cylinder that operates the disc brake of vehicles such as motorcycles, and relates to a switch that turns on the brake light when the brake lever is squeezed or the brake pedal is depressed. It is.

Normally, the master cylinder of a brake brakes the vehicle by transmitting the force of gripping the brake lever or pressing the brake pedal to the disc brake pads using hydraulic pressure. At this time, it will notify the following vehicle to stop.

Conventionally, especially in rear wheel braking of motorcycles,
When you step on the brake pedal, as shown in Figure 1,
Mechanical switch 1 was activated and the brake lights were turned on. That is, when the brake pedal 2 is depressed in the direction of the arrow in the figure, the other end of the brake pedal 2, which is supported around the shaft 3, pushes up the push rod 4 in the direction of the arrow, thereby operating the master cylinder 5. At the same time, the switch 1 is actuated via a spring 6 secured to the approximate center of the brake pedal 2, and the brake light is turned on.

In this case, as can be seen in the figure, a switch 1 is attached to a brake pedal 2 via a spring 6 to a vehicle body (not shown). This switch 1
Since the parts are exposed to wind and rain, they sometimes rust or collect dust, making it difficult to operate smoothly.

The present invention was developed to solve the above problem, and includes a switch built into the master cylinder.

Embodiments of the present invention will be described below with reference to the drawings.
In FIGS. 2 and 3, 7 is the body of the master cylinder, 8 is a piston fitted in the master cylinder body 7, and 9 is a primary cup fixed to the piston head 8a. A return spring 1 is installed between the master cylinder body 7 and the piston 8.
0 is interposed, and always pushes the piston 8 downward in the figure. A secondary cup 11 is fixed to the piston body 8b, and together with the primary cup 9, prevents leakage of the pressure fluid in the hydraulic pressure chamber 12. 13 is a retainer, and 14 is a piston stop, both of which prevent the piston 8 from coming off from the master cylinder body 7. Reference numeral 15 denotes a + side contact, which is installed in an insulator 17 buried in the inner wall of the master cylinder body 7, and a lead wire 18.
is connected to the battery. Reference numeral 16 denotes a contact mounted in the piston leg 8c opposite the contact 15, and the piston 8 is connected to the master cylinder body 7.
When it slides inside, it contacts the contact point 15. It is preferable that the contact 16 is always pressed against the master cylinder body 7 by a spring 20 or the like inserted in the recess 19 of the piston leg 8c, as shown in FIG. Further, instead of the spring 20, a leaf spring may be fixed to the bottom of the recess 19 with screws.

The present invention is constructed as described above, and when the piston rod 4 is pushed up as shown by the arrow in FIG. Push up. Then, as indicated by the dashed line in FIG. 3, the contact 15 on the master cylinder body 7 side and the contact 16 on the piston leg 8c come into contact, and are connected to the battery via the lead wire 18, turning on the brake light.

As described above, according to the present invention, compared to conventional mechanical switches, the switch mechanism is not exposed to the outside, so it is possible to prevent rust and dust from accumulating.

Furthermore, since the switch for turning on the brake light is built into the master cylinder, there is no need for a mounting part for the switch mechanism, resulting in a cleaner appearance, a reduction in the number of parts, and improved assembly work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing a conventional brake system, FIG. 2 is a sectional view of a master cylinder according to the present invention, and FIG. 3 is a partially enlarged sectional view of FIG. 2. 7... Master cylinder body, 8... Piston, 8a... Piston head, 8b... Piston body, 8c... Piston leg, 9... Primary cup, 10... Return spring, 15, 16
... Contact, 17 ... Insulator, 18 ... Lead wire.

Claims (1)

[Scope of utility model registration request] In a brake master cylinder that transmits the grip force of a brake lever or the force of pressing a brake pedal to a piston fitted in a master cylinder body via a push rod, and brakes a vehicle by the hydraulic pressure generated from the piston, the above-mentioned master cylinder is used. A contact is embedded in the inner wall of the body through an insulator, and a contact that slides in opposition to the contact is attached to the leg of the piston, so that the contact contacts as the piston slides and lights up the brake light. A brake master cylinder with a built-in brake light switch.