JPS6238845Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a master cylinder equipped with a brake switch mechanism, and more particularly to a master cylinder in which a brake switch mechanism for opening and closing the brake lamp of a vehicle is incorporated into the master cylinder.

Conventionally, in master cylinders in which a piston is slidably fitted into the cylinder body and the operating force applied to the piston is converted into hydraulic pressure, a brake switch is fitted into a hole parallel to the push rod that pushes the piston into the cylinder body. It is known that the brake switch is fixed, and the movable contact of the brake switch protrudes from the cylinder body and faces a plate provided on the push rod or the brake pedal, and the brake lamp is controlled to open and close in response to the operation of the brake pedal.

The purpose of the present invention is to incorporate the brake switch, which is attached to the outside of the cylinder body of the master cylinder, into the cylinder body, so that the brake switch does not increase the size of the master cylinder, and in addition, the brake switch can be directly operated by the actuation of the piston. To provide a master cylinder equipped with a brake switch mechanism which can be opened and closed and whose operation is more reliable without variation in operation timing.

In accordance with the above object, the present invention provides a master cylinder in which a piston is slidably fitted into a cylinder body and converts operating force applied to the piston into hydraulic pressure. At the same time, a magnetically responsive reed switch connected to the brake lamp is housed in the switch housing.
Further, a magnet is provided on the piston perpendicularly to the piston axis and parallel to the reed switch so as to operate the reed switch, and piston rotation preventing means is provided for holding the magnet parallel to the magnetically responsive reed switch. It is characterized by this.

Hereinafter, an embodiment in which the present invention is applied to a vertical master cylinder of a two-wheeled vehicle will be described based on the drawings.

A piston 3 is slidably fitted into a cylinder hole 2 formed in a cylinder body 1 of a vertical master cylinder, thereby forming a pressure liquid chamber 4 and a pressureless liquid chamber 5.
are defined respectively. The pressure fluid chamber 4 is provided with an output port 6, to which a brake fluid pressure circuit is connected. A reservoir 7 is attached to the side wall of the cylinder body 1, and when the brake is not applied in the state shown in FIG. It communicates with

A dust boot 1 is provided at the bottom of the cylinder body 1 between the cylinder opening 10 and the piston head 11.
2 is provided to prevent sand, water, etc. from entering the cylinder hole 2.

A switch storage portion 1a is formed in the cylinder opening 10 and is arranged in a direction perpendicular to the cylinder axis.
A reed switch board 14 to which a magnetically responsive reed switch 13 is attached is housed in the switch housing 1a, and one end of this reed switch board 14 abuts against a positioning step 15 formed in the cylinder opening 10. , the other end is filled with adhesive 16 and fixed. A magnet 17 is press-fitted into the piston head 11 in a direction perpendicular to the piston axis. This magnet 17 is parallel to the reed switch 13, which is disposed facing inside the cylinder. In this example, the magnet 17
is press-fitted in a direction perpendicular to the piston axis, but it only needs to be perpendicular to the piston axis, and the distance from the reed switch 13 can be freely set depending on the strength of the magnetic force of the magnet 17.

The magnet 17 and the reed switch 13 are always held parallel to each other by the piston rotation prevention means A. The piston rotation prevention means A includes a guide groove 18 formed in the piston end 11 in the piston axial direction.
and a spring pin 19 which is inserted into the cylinder opening 10 and whose tip engages with the guide groove 18, restricts the rotation of the piston 3, and comes into contact with the collar 3a of the piston 3 to prevent a return spring. 20 restricts the position of the piston 3 in the backward direction.

Next, to explain the operation of this embodiment, in the non-braking state shown in FIG.
contacts the collar portion 3a of the piston 3, and the magnet 17 is in a position parallel to the magnetically responsive reed switch 13, so the reed switch 13 is closed by the magnetic force of the magnet 17. However, since the B contact 22 is turned off due to the operation of the relay coil 21, the brake lamp 23 is turned off.

Next, when the actuating lever (not shown) is rotated to press the piston head 11 and move the piston 3 forward, the pressure fluid 4 is increased in pressure, and the pressure fluid is supplied from the output port 6 to the brake device. can be braked.

At the same time, as the piston 3 moves forward, the magnetic force of the magnet 17 no longer acts on the reed switch 13, so the reed switch 13 opens, the B contact 22 switches from the OFF state to the ON state, and the brake lamp 23 lights up. This allows the driver to sense that the vehicle is in a braking state.

When the brake is released, the piston 3 returns to its initial position by the return spring 20, and the magnetic force of the magnet 17 acts on the reed switch 13 again to close its contact, and by the action of the relay coil 21, the B contact 22 is switched from the on state to the off state, and the brake lamp 23 is turned off.

When the master cylinder is operated, the piston 3 moves forward and backward within the cylinder hole 2, but its rotation is prevented by the piston rotation prevention means A, so that the magnet 17 and the reed switch 13 can always be maintained in a parallel state. Good opening/closing operation.

Furthermore, the retraction limit of the piston 3 can be set by the piston rotation preventing means A, and there is no need to provide a separate mechanism for setting the retraction limit of the piston, so the structure is simple.

As described above, according to the present invention, a magnetically responsive reed switch is arranged in the cylinder opening of the cylinder body in a direction perpendicular to the cylinder axis, and a magnet perpendicular to the piston axis is attached to the piston, and the reed switch is connected to the reed switch by the piston rotation preventing means. Since the reed switch is opened and closed by holding the reed switch parallel to the piston, the brake lamp lights up due to the operation of the piston, allowing the driver to more reliably sense whether or not the brake is being applied. The reed switch is built into the conventional cylinder body and does not protrude outside like in the past, so the switch mechanism does not increase the size of the master cylinder, making it particularly easy to install in master cylinders for motorcycles. This is even more advantageous due to space constraints.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view of a master cylinder for a two-wheeled vehicle to which the present invention is applied, and FIG. 2 is a cross-sectional view taken from FIG. 1. 1 is the cylinder body, 1a is the switch storage part, 3
1 is a piston, 10 is a cylinder opening, 11 is a piston head, 13 is a magnetically responsive reed switch, 1
4 is a reed switch board, 17 is a magnet, 1
8 is a guide groove, 19 is a spring pin, and A is a piston rotation prevention means.

Claims (1)

[Scope of utility model registration request] The piston is slidably fitted into the cylinder body,
In a master cylinder that converts operating force applied to a piston into hydraulic pressure, a switch housing is formed in the cylinder opening of the cylinder body in a direction orthogonal to the cylinder axis, and the switch housing is connected to a brake light. A magnetically responsive reed switch is housed, and a magnet is provided on the piston perpendicularly to the piston axis and parallel to the reed switch so as to operate the reed switch, and the magnet is installed parallel to the magnetically responsive reed switch. A brake switch mounting device for a master cylinder, characterized in that it is equipped with means for holding a piston to prevent rotation.