JPH1053184A - Hydraulic master cylinder with brake switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve brake actuation detecting accuracy by turning on a brake switch and lighting a stop lamp by the movement of an operating element following the movement of a piston at the time of the piston moving in association with the actuation of a push rod. SOLUTION: When a brake pedal or a brake lever is operated to move a push rod 20 leftward, a piston 7 in contact with the head part of the push rod 20 moves left so as to generate hydraulic pressure in a hydraulic pressure chamber 8, and this hydraulic pressure is fed to a wheel cylinder through brake piping to put a brake in action. In association with the leftward movement of the piston 7 at this time, an operating element 16c of a brake switch 16 is also moved left following the movement of the piston 7 by the energizing force of a spring in the switch, so that the brake switch is turned on, and a stop lamp is lighted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic master cylinder for hydraulically operating a vehicle brake, and more particularly, to a hydraulic master cylinder having a brake switch for turning on a stop lamp in conjunction with generation of hydraulic pressure. It relates to a pressure master cylinder.

[0002]

2. Description of the Related Art Conventionally, there is known a hydraulic master cylinder for a vehicle equipped with a brake switch described in Japanese Patent Publication No. 4-2158, which makes it easy to mount and replace the brake switch. In this hydraulic master cylinder for a vehicle with a brake switch, a stop ring which is prevented from falling off on an opening side of a cylinder hole formed in a cylinder body is provided with a head end of a push rod for pushing a piston inserted in the cylinder hole. The hydraulic master cylinder for a vehicle, comprising: a brake switch for stopping the push rod during non-operation and restricting a retraction limit of the push rod when the cylinder is not operated; A ramp is provided so as to be movable toward the bottom of the cylinder hole as the push rod advances, and a brake switch is fixed to the inner periphery of the cylinder hole on the opening side of the stop ring. In the position, it is pressed by the stop ring, and when the push rod is actuated, the pressure is released. It is characterized in that a working element which projects are. In the device having the above configuration, the brake switch is provided on the opening side of the stop ring, so that not only new installation but also replacement work can be performed easily in a short time. Replacement work that has been performed can be eliminated.

[0003]

However, in the above device, the brake switch is arranged on the inner hole side of the cylinder body covered with the boot, so that the brake switch is housed in the cylinder body side. Space must be provided, and the mounting work is troublesome because the boots must be removed one by one. In addition, because the brake switch is mounted on the inner hole side of the cylinder body, it is not easy to adjust the position of the stop ring and the brake switch, and there is variation in the detection of hydraulic pressure, and sufficient braking force is generated. However, inconveniences such as the stop lamp not being lit may occur. Since the brake operation state is detected by the movement of the stop ring fixed to the push rod, the movement of the piston for generating hydraulic pressure cannot be directly detected. A slight shift may occur between the time when the lamp is turned on and the time when the lamp is turned on.

Therefore, the present invention makes it possible to detect the operation of the brake switch directly from the movement of the hydraulic piston as much as possible, simplify the structure of the master cylinder, and further reduce the number of parts. It is an object of the present invention to provide a hydraulic master cylinder with a brake switch which can reduce the number of assembly steps and the number of assembly steps, thereby improving the accuracy of brake operation detection and reducing costs.

In the hydraulic master cylinder with a brake switch according to the present invention, the movement of the hydraulic piston can be detected directly or almost directly through a small number of parts, so that the detection accuracy at the time of brake operation is improved. Inconveniences such as delay in lighting of the stop lamp can be eliminated. In addition, since the brake switch is configured to be externally attached to the master cylinder, assembly of the brake switch is facilitated, and adjustment of the mounting position of the brake switch is also simplified.

[0006]

For this reason, the technical solution adopted by the present invention is to move the piston in the master cylinder along with the movement of the push rod to generate brake hydraulic pressure, In a master cylinder with a brake switch that can light a stop lamp in conjunction with the movement of the rod, the piston is prevented from coming off from the cylinder body by a stopper plate attached to the cylinder body, and the stopper plate has a notch. The actuator of the brake switch externally attached to the cylinder body is inserted into the notch so that the actuator and the piston come into contact with each other. Move following the movement, turn on the brake switch and stop lamp A hydraulic master cylinder with a brake switch, characterized in that it is configured to be turned on, and a piston in the master cylinder can be moved with the movement of the push rod to generate brake hydraulic pressure, and the push rod In a master cylinder with a brake switch capable of lighting a stop lamp in conjunction with movement, a radial step is formed on the push rod, and an actuator of a brake switch externally attached to the cylinder body 3 is applied to the step. A hydraulic master cylinder with a brake switch, characterized in that the actuator is moved in accordance with the movement of the push rod, and the stop switch is turned on by turning on the brake switch in accordance with the movement of the push rod. .

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a hydraulic master cylinder with a brake switch according to the present invention; FIG. 2 is a sectional view showing a brake switch, a push rod and a piston; FIG. 3 is an enlarged cross-sectional view and a front view of a brake switch portion in a state where a retainer ring and the like are removed in order to facilitate understanding of a stopper plate.

In each of the drawings, a master cylinder 1 has a cylinder body 3 having a cylinder hole 2 formed therein, and a reservoir 6 that communicates with the cylinder hole 2 via a relief port 4 and a supply port 5. It is configured as a figure. A piston 7 for generating hydraulic pressure is provided in the cylinder hole 2.
Are fluid-tightly and movably fitted, and a hydraulic chamber 8 is defined in the cylinder hole 2. The piston 7 is provided with a spring seat 9, and a spring 10 for urging the piston 7 rightward in the drawing is disposed in a hydraulic chamber 8 formed between the spring seat 9 and the cylinder body 3. I have.
A primary cup 11 and a secondary cup 12 are provided on the outer periphery of the piston 7 as is well known.

The piston 7 is constantly urged rightward in the figure by a spring 10 disposed in the hydraulic chamber 8, and the piston 7 is fixed to the step 3a of the cylinder body 3 by a retainer ring 14. The stopper plate 13 prevents the stopper plate from coming off. The head of the push rod 20 is in contact with the end of the piston 7, and when the push rod 20 is pushed to the left in the drawing, the piston 7 moves to generate a hydraulic pressure in the hydraulic chamber 8. . A rod boot 15 for preventing dust from entering is provided between the push rod 20 and the cylinder body 3. As shown in FIGS. 2 and 3, the stopper plate 13 is
An operator 16c of the brake switch 16, which will be described later, is disposed in the notch (gap) 13a.

The brake switch 16 includes a switch cover 16a, a switch main body 16b, and an operator 16c for turning on and off a switch inside the main body. It is externally fixed to the cylinder body 3 by bolts 17 or the like so as to be orthogonal. The actuator 16c of the brake switch 16 is configured to be urged leftward in FIGS. 1 and 3 by a spring (not shown) provided inside the main body, and when it is attached to the cylinder body 3, The actuator 16c is brought into contact with the end face of the piston 7 by the urging force of the spring, and the switch is kept off. A switch boot 18 for preventing dust and the like from entering is mounted between the brake switch 16 and the cylinder body 3.

The operation of the hydraulic master cylinder with a brake switch having the above configuration will be described. In FIG. 1, when the brake pedal or the brake lever is operated and the push rod 20 moves to the left in the figure, the piston 7 in contact with the head of the push rod 20 moves to the left. Hydraulic pressure is generated in the hydraulic pressure chamber 8, and this hydraulic pressure is supplied to the wheel cylinder via the brake pipe to operate the brake. At this time, the movement of the piston 7 to the left causes the actuator 16c of the brake switch 16 to move.
The piston 7 is also activated by the biasing force of the spring inside the switch.
Then, the brake switch is turned on and the stop lamp is turned on. When the brake is released, the piston 7 returns to the initial state by the urging force of the spring 10 in the hydraulic chamber 8, and the end face of the piston 7 pushes the brake switch actuator 16c against the urging force of the spring in the brake switch. Then, in order to return to the state shown in FIG. 1, the brake switch 16 is turned off and the stop lamp is turned off.

As described above, in the present apparatus, the operating member 16c for turning on and off the brake switch 16 is in direct contact with the piston 7 that generates hydraulic pressure. It is possible to detect directly, the detection accuracy at the time of braking is improved,
Inconveniences such as a delay in lighting the stop lamp can be eliminated. Further, since the brake switch 16 can be externally attached to the cylinder body 2 of the master cylinder, it is easy to assemble the brake switch 16 into the master cylinder. Since the mounting position of the brake switch is adjusted simply by arranging and fixing the brake switch 7 so as to be in a contact state, the complicated switch mounting adjustment as in the related art is unnecessary.

Next, another embodiment of the present invention will be described with reference to the drawings. FIGS. 4A to 4C are explanatory diagrams showing the relationship between the piston and the operating element. The first embodiment has a configuration in which the actuator 16c of the brake switch directly contacts the end face of the piston 7 as shown in FIGS.
The second and third embodiments shown in FIGS. 4A and 4B are characterized in that the actuator fits into a radial step or groove formed on the piston 7 end face. That is, in the embodiment shown in FIG. 4A, a radial step 7a is provided at the end of the piston 7,
An operator 16c of the brake switch 16 is loosely fitted in the step. In the embodiment shown in FIG. 4B, a groove 7b is provided at the end of the piston 7, and an actuator 16c of the brake switch is loosely fitted in the groove. In either case, since the movement of the piston 7 can be directly detected, the detection accuracy is good.

The fourth embodiment shown in FIG. 4C is characterized in that the movement of the piston can be detected almost directly through the movement of the push rod 20. In this embodiment, a stopper plate provided with a notch is not always necessary as in the first embodiment, and the movement of the push rod can be detected at a position where the stopper plate is removed. In this embodiment, a step 20a in the radial direction is provided on the head of the push rod 20, and the actuator 16c of the brake switch comes into contact with the step.
In this case, the movement of the piston 7 cannot be directly detected, but the movement of the piston can be detected almost directly via the push rod 20. The detection accuracy is improved as compared with the detection of the operation state.

[0015]

As described above in detail, according to the present invention, 1) the operation of the brake switch can be detected almost directly from the movement of the hydraulic piston, so that the accuracy of the brake operation detection can be improved. Cost can be reduced. 2) Since the configuration in which the brake switch is externally attached to the master cylinder body is adopted, the number of assembly steps can be reduced. 3) The master cylinder can be shared regardless of the structure of the brake pedal and the brake lever. 4) The structure of the master cylinder can be simplified, the number of parts can be reduced, and the cost can be reduced. 5) Adjustment of the mounting position of the brake switch is facilitated. And other excellent effects.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic master cylinder with a brake switch according to an embodiment of the present invention.

FIG. 2 shows a brake switch, a push rod,
It is a perspective sectional view showing piston arrangement relation.

FIG. 3 is an enlarged cross-sectional view and a front view of a brake switch portion of the same device excluding a retainer ring and the like.

FIG. 4 is an explanatory diagram showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Master cylinder 2 Cylinder hole 3 Cylinder body 7 Piston 8 Hydraulic pressure chamber 10 Spring 13 Stopper plate 14 Retainer ring 15 Boot 16 Brake switch 16a Switch cover 16b Switch body 16c Actuator 17 Bolt 18 Switch boot 20 Push rod

Claims (4)

[Claims] A brake fluid pressure can be generated by moving a piston in a master cylinder in accordance with the movement of a push rod, and a stop lamp is turned on in conjunction with the movement of the push rod. In the master cylinder with the brake switch 16 which can be provided, the piston 7 is prevented from coming off from the cylinder body 3 by a stopper plate 13 attached to the cylinder body 3, and the stopper plate 13 is provided with a notch 13a. The actuator 16c of the brake switch 16 externally attached to the cylinder body 3 is inserted into the cylinder body 3 to bring the actuator 16c into contact with the piston 7. When the piston 7 moves with the operation of the push rod 20, the actuator 16c also Move following the movement of the piston 7 and turn on the brake switch. Hydraulic pressure master cylinder with a brake switch, characterized by being configured so as to light the stop lamp. 2. An operator 16c of the brake switch 16.
2. The structure according to claim 1, wherein the radial stepped portion 7a formed at the end of the piston contacts the piston.
2. A hydraulic master cylinder with a brake switch according to the item 1. 3. An actuator 16c of the brake switch,
The hydraulic master cylinder with a brake switch according to claim 1, wherein the hydraulic master cylinder with a brake switch is configured to abut on the piston 7 at a groove 7b formed at an end of the piston. 4. A brake fluid pressure can be generated by moving the piston 7 in the master cylinder with the movement of the push rod 20, and a stop lamp can be turned on in conjunction with the movement of the push rod 20. In a master cylinder with a brake switch, a radial stepped portion 20a is formed on the push rod 20,
The actuator 16c of the brake switch 16 externally attached to the cylinder body 3 is brought into contact with 0a, and with the operation of the push rod 20, the actuator 16c also moves following the movement of the push rod 20, and the brake switch 16 is turned on. A hydraulic master cylinder with a brake switch, which is configured to light a stop lamp.