JPH0439113Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a foot-operated hydraulic brake device for small vehicles such as motorcycles.

Prior Art and its Problems FIGS. 1 and 2 show an example of a known foot-operated hydraulic brake device for a motorcycle. 1st
The figure shows the main parts of the right side of the vehicle.
A step support member 02 extending toward the rear wheel RW side is fixed to the vehicle body frame 01 located near the rear of the vehicle, and the step support member 02 has a step (footrest bar) 03 for the driver and a step 04 for the passenger. has been done. In addition, the step support member 02 includes:
Brake pedal 05, hydraulic master cylinder 0
8 is attached. A support shaft 06 of the brake pedal 05 passes through the step support member 02 from the outside to the inside of the vehicle body, and a swing arm member 07 is attached to the tip of the support shaft 06 so as to be relatively non-rotatable.

The hydraulic master cylinder 08 is attached to the inside surface of the step support member 02, and a piston housed in the cylinder body 09 is moved by a push rod 011 (FIG. 2).
This push rod 011 is connected to one end of the swinging arm member 07, and is a tension rod bridged between the other end of the swinging arm member 07 and a hook 012 attached to the step support member 02. It is biased in the direction of arrow A by a coil spring 013 and a piston return compression coil spring 010 housed in the cylinder.
Tension coil spring 013, compression coil spring 010
not only biases the push rod 010 but also biases the brake pedal 05 in the direction of arrow B (return direction).

The reason why the tension coil spring 013 is used in addition to the compression coil spring 010 as the biasing spring is that in a foot-operated brake system, a large spring reaction force is required to obtain a feeling of pedal operation, and the stroke of the piston is This is because the cylinder is relatively large and the spring housing space within the cylinder is small, making it impossible to accommodate a compression coil spring with a sufficiently large resiliency force within the cylinder.

In such a structure using the tension coil spring 013, it is necessary to provide the spring locking portion 07a on the swinging arm member 07 and to attach the hook piece 012 to the step support member 02.
Since the space for arranging the spring must be allocated in a narrow and limited space on the surface of the brake pedal, and the degree of freedom in arranging the spring is small, the brake pedal 05 may have to be intentionally bent. In a vehicle in which the mounting position of the brake pedal 05 can be changed to a higher or lower position depending on the driver's preference or physique, there is a drawback that the spring reaction force changes depending on the mounting position.

Means to Solve the Problems The present invention was devised against this technical background, and consists of a hydraulic master cylinder that has a built-in piston inside the cylinder body that is pushed by a push rod, and is located near the brake pedal. , a foot-operated hydraulic brake system in which the push rod is moved by operating the brake pedal, does not require a special hook for locking the return spring for the brake pedal and the push rod, and the mounting height of the brake pedal can be reduced. The object of the present invention is to provide a foot-operated hydraulic brake device that can set a spring reaction force regardless of the position of the foot.

This objective is achieved by interposing a return compression coil spring between the cylinder body and the push rod which moves relative to the cylinder body.

Embodiment Hereinafter, an embodiment of the present invention shown in FIGS. 3 to 5 will be described.

FIG. 3 shows a motorcycle 10 with an engine E mounted between the front and rear wheels FW and RW as a right side view of the vehicle body. A rear fork 14 is supported by the vehicle body frame 12 at point P so as to be swingable in the vertical direction.
A hydraulic disc brake device 56 is installed at the rear end.
The rear wheel RW with is supported.

The disc brake device 56 is activated by operating the brake pedal 20 located near point P. The brake pedal 20 is swingably supported by a support shaft 22 of a step support member 16 projecting from the vehicle body frame 12, and is located close to the step 18. The support shaft 22 of the brake pedal 20 passes through the step support member 16 from the outside to the inside of the vehicle body, and has a swing arm member 24 similar to the swing arm member 07 in FIG. 2 at the tip of the step support member 16. are mounted so that they cannot rotate relative to each other.

On the inside surface of the step support member 16,
The hydraulic master cylinder 26 is screwed onto the cylinder body 28 using protrusions 30, 30.
The cylinder main body 28 is a hollow cylindrical body with both ends open, a push rod guide cylinder 40 is screwed into one end, and a brake hose 54 is connected to the other end. Further, in the cylinder hole of the cylinder body 28, a piston 32, a compression coil spring 36 for pushing back the piston 32, and a compression coil spring 3 are provided.
6, an oil pressure element 34 which also serves as a spring seat, a tip half of the push rod 42 that penetrates the push rod guide tube 40 and presses the rear end of the pin strike 32, and a press head of the push rod 42 that engages with the pressure head of the push rod 42. Annular stopper 38 to prevent detachment
(The annular stopper 38 itself is prevented from coming off by a circlip 38a). A screw is formed at the rear end of the push rod 42, and a connector 44 and a hexagonal nut 48 are screwed into the screw, and a spring seat 50 supported by the hexagonal nut 48 is fitted onto the outside. The center axis of the rod 42 coincides with the spring seat 50 and the push rod guide cylinder 4.
A compression coil spring 52 is interposed between the two.
This compression coil spring 52 biases the push rod 42 in the direction of arrow A via the spring seat 50, and the previous compression coil spring 36 biases the push rod in the backward direction via the oil pressurizer 34. The end of the swing arm member 24 is swingably connected to an annular portion 46 formed at the rear end of the connector 44.

Therefore, when the brake pedal 20 is depressed and operated, the push rod 42 moves in the direction of the arrow C, the piston 32 and the oil pressurizer 34 move forward, the pressure oil in the cylinder hole is pushed out, and the pressure oil in the caliper cylinder of the disc brake device 56 is pushed out. Pressure oil enters the caliper piston and moves the pair of friction pads to the disk 58.
Braking of the rear wheel RW is performed by slidingly contacting both sides of the rear wheel RW. Next, when you release your foot from the brake pedal 20, the push rod 42 is pulled out in the direction of arrow A by the elastic force of the compression coil spring 52, and the oil pressurizer is pulled out by the elastic force of the compression coil spring 36. 34,
The piston 32 is pushed back and the disc brake device 56 becomes inactive.

The features of this embodiment are as follows.

Since the compression coil spring 52 is integrally assembled with the hydraulic master cylinder 26, it is not necessary to provide a spring hook on the step support member 16 and form a spring locking portion on the swing arm member 24. The shapes of the step support member 16 and the swing arm member 24 are simplified accordingly,
It is possible to plan to reduce production costs.

By using the compression coil spring 36 instead of the tension coil spring as the return spring for the push rod 42 and the brake pedal 20, the compression coil spring 52 is assembled to the hydraulic master cylinder 26 with its center axis aligned with the push rod 42. structure became possible.

In the structure in which the compression coil spring 52 is assembled outside the cylinder body 28, its shape is smaller than that of the compression coil spring 36 provided inside the cylinder chamber.
Since the dimensions can be selected with a high degree of freedom, a sufficiently large spring reaction force can be applied to the brake pedal 20.

The space for the tension coil spring that was conventionally required near the hydraulic master cylinder and brake pedal is no longer required, and the degree of freedom in arranging the hydraulic master cylinder 26 and the brake pedal 20 is increased.

The elastic force of the compression coil spring 52 is always constant regardless of the mounting position of the brake pedal 20. Therefore, not only can the mounting position of the brake pedal 20 be freely selected, but also the shape of the brake pedal 20 can be selected freely. The degree of freedom is also improved.

Effects of the invention As is clear from the above explanation, the foot-operated hydraulic system for small vehicles is constructed by interposing a compression coil spring for return between the cylinder body and the push rod that moves relative to the cylinder body. A brake device was proposed.

This device adopts a structure in which the compression coil spring for returning the push rod and brake pedal is assembled integrally with the hydraulic master cylinder, so there is no need for a hook for locking the spring. The dedicated space for the return spring, which was required nearby, can be omitted. In addition, the spring force of the return compression coil spring can be set regardless of the mounting position of the brake pedal, so the mounting position of the brake pedal can be selected with great freedom according to the driver's preference and physique. obtain.

[Brief explanation of the drawing]

FIG. 1 is a right side view of the main parts of a motorcycle equipped with a known foot-operated hydraulic brake device, FIG. 2 is a view of the foot-operated hydraulic brake device viewed from the center side of the vehicle body in the vehicle width direction, and FIG. The figure is a right side view of a motorcycle equipped with a foot-operated hydraulic brake device according to an embodiment of the present invention, and FIG. 4 is a sectional view of essential parts showing a hydraulic master cylinder assembly in the foot-operated hydraulic brake device. , FIG. 5 is a view taken along the line V-V. 10...Motorcycle, 12...Vehicle frame,
14... Rear fork, 16... Step support member, 18... Step, 20... Brake pedal, 22... Support shaft, 24... Swinging arm member, 26...
... Hydraulic master cylinder, 28 ... Cylinder body, 30 ... Protrusion, 32 ... Piston, 34 ...
...Oil pressurizer, 36...Compression coil spring, 38...
Annular stopper, 40...Push rod guide tube, 42...
... Push rod, 44 ... Connector, 46 ... Annular part, 4
8...Hexagonal nut, 50...Spring seat, 52...Compression coil spring, 54...Brake hose, 56...
...Disc brake device, 58...Disc, E
...engine, FW...front wheel, RW...rear wheel.

Claims (1)

[Scope of claim for utility model registration] A foot-operated hydraulic system in which a hydraulic master cylinder with a built-in piston that is pushed by a push rod is placed near the brake pedal, and the push rod is moved by operating the brake pedal. A foot-operated hydraulic brake device for a small vehicle, characterized in that a compression coil spring for return is interposed between a cylinder body and a push rod that moves relative to the cylinder body.