JPH0331647Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a reservoir for a master cylinder used in a brake device or a clutch device of motorcycles, tricycles, three-wheeled buggies, etc.

[Conventional technology]

Conventionally, this type of reservoir has a flexible diaphragm sandwiched between caps around the mouth of the reservoir to prevent air bubbles generated by vibrations caused by driving from entering the working fluid and causing vapor lock. , the atmospheric chamber formed between the lower surface of the cap and the diaphragm is communicated with the outside via an atmospheric communication hole, and the diaphragm is able to follow the liquid level and is sealed to prevent the generation of bubbles due to vibrations during running. There is a type.

[Problem that the invention attempts to solve]

However, with the type that uses a diaphragm, the hydraulic fluid permeates through the diaphragm over time and accumulates on the diaphragm, and when the vehicle body is tilted, the hydraulic fluid leaks to the outside from the atmosphere communication hole, causing oil in the reservoir. Inconveniences such as contamination due to adhesion of dirt and dust and clogging of the air communication holes have occurred.

Therefore, the object of the present invention is to provide a master cylinder reservoir that can store the working fluid that permeates onto the diaphragm on the atmospheric chamber side in the atmospheric chamber and prevent it from leaking out of the reservoir through the atmospheric communication hole. .

[Means for solving problems]

In order to solve the above object, the present invention has been developed by sandwiching the peripheral edge of a diaphragm, which has a flexible part that can be raised and lowered according to the level of the hydraulic fluid, between the lip of the reservoir that stores the hydraulic fluid and the cap. In the reservoir of a sealed master cylinder that forms an atmospheric chamber between the diaphragm and the lower surface of the cap, the reservoir is placed on the atmospheric chamber side of the diaphragm and covers the liquid level of the hydraulic fluid and is not in contact with the lower surface of the cap. A rib that surrounds the flexible part, has an upper edge in contact with the lower surface of the cap, and an outer peripheral surface in contact with the inner peripheral surface of a protrusion protruding from the lower surface of the cap, is attached to the inside of the peripheral edge on the outer periphery of the flexible part. It is characterized by being built upright.

[Function] With the above structure, the hydraulic fluid passing through the diaphragm is sealed between the upper edge of the surrounding rib and the lower surface of the cap, and between the outer circumferential surface of the surrounding rib and the inner circumferential surface of the protrusion formed on the lower surface of the cap. Store in
Prevents leakage outside the reservoir.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

A master cylinder 1 used in a brake device or a clutch device includes a reservoir 2 that stores hydraulic fluid F;
A cylinder body 3 is integrally formed into which a piston (not shown) that communicates with the reservoir 2 and pumps the hydraulic fluid F is inserted.

The reservoir 2 has a peripheral edge 4 on its mouth edge 2a.
The diaphragm 4, which is fluid-tightly sandwiched between the cap 5 and the mouth edge 2a, receives the hydraulic fluid F.
diaphragm 4 and cap 5
An atmospheric chamber 6 is defined between the cap 5 and the cap 5, and an atmospheric communication hole 7 is formed in the cap 5.

The diaphragm 4 has the mouth edge 2 of the reservoir 2 on its outer periphery.
The peripheral edge 4a placed on the cap 5 and sandwiched by the cap 5 is not in contact with the lower surface 5a of the cap 5,
There is a flat bottom part 4b in the center that contacts the surface of the hydraulic fluid F and follows the displacement of the liquid level, and a flat bottom part 4b around the flat bottom part 4b so that the flat bottom part 4b follows the displacement of the liquid surface of the hydraulic fluid F. It has a flexible portion 4e consisting of a bellows portion 4c formed on the diaphragm 4 and a flat portion 4d that is provided around the bellows portion 4c and easily comes into contact with the hydraulic fluid F. Flexible part 4
A rib 4f surrounding the flexible portion 4e is erected inside the peripheral portion 4a on the outer periphery of the flexible portion 4e.

The upper edge 4g of this rib 4f comes into contact with the lower surface 5a of the cap 5 when the diaphragm 4 is held between the mouth edge 2a of the reservoir 2 and the cap 5, and the outer peripheral surface of the rib 4f contacts the lower surface 5a of the cap 5. They are formed so as to abut on the inner circumferential surfaces of the protruding ridges 5b, respectively.

With the above configuration, when the hydraulic fluid F passes through the diaphragm 4 and accumulates in the flexible portion 4e of the diaphragm 4 due to long-term use, the rib 4f
The upper edge 4g and the outer peripheral surface are the lower surface 5a of the cap 5.
Since the atmospheric chamber 6 is sealed by contacting the protrusion 5b, the hydraulic fluid F will not leak directly to the outside even if the vehicle body is tilted.

In addition, the bottom flat portion 4b
As the rib 4f follows, the rib 4f bends due to the pressure difference between the atmospheric chamber 6 and the outside, and its upper edge 4g separates from the lower surface 5a of the cap 5, and its outer circumferential surface separates from the inner circumferential surface of the protrusion 5b, creating a gap. Since the atmosphere enters the atmospheric chamber 6 through this gap, the diaphragm 4 operates smoothly.

Incidentally, a groove may be formed on the lower surface 5a of the cap 5 against which the upper edge 4g of the rib 4f comes into contact, allowing the atmospheric chamber 6 and the atmospheric communication hole 7 to communicate with each other.

[Effect of idea]

As described above, the present invention involves sandwiching the peripheral edge of a diaphragm, which has a flexible part that can be raised and lowered according to the level of the hydraulic fluid, between the lip of the reservoir that stores the hydraulic fluid and the cap. In the reservoir of a sealed master cylinder that forms an atmospheric chamber between the diaphragm and the lower surface of the cap, the flexible portion is provided on the atmospheric chamber side of the diaphragm and covers the liquid level of the working fluid and is not in contact with the lower surface of the cap. A rib that surrounds the cap and whose upper edge abuts the lower surface of the cap and whose outer circumferential surface abuts the inner circumferential surface of a protrusion protruding from the lower surface of the cap is erected on the outer periphery of the flexible portion and inside the circumferential edge. Therefore, the working fluid that has passed through the diaphragm and accumulated on the diaphragm can be sealed in the atmospheric chamber and can be prevented from directly leaking to the outside.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a partially sectional front view of a master cylinder, and FIG. 2 is a plan view of a diaphragm. 1...Master cylinder, 2...Reservoir, 2a
...Reservoir mouth edge, 4...Diaphragm, 4a
...Diaphragm peripheral part, 4e...Flexible part, 4f
...Rib, 4g...Rib upper edge, 5...Cap, 5a...Cap bottom surface, 5b...Protrusion, 6...
... Atmospheric chamber, F... Working fluid.

Claims (1)

[Scope of utility model registration request] The peripheral edge of a diaphragm having a flexible part that can be raised and lowered according to the level of the hydraulic fluid is held between the cap and the lip of the reservoir that stores the hydraulic fluid, and the diaphragm and the lower surface of the cap are sandwiched between the diaphragm and the cap. In the reservoir of a sealed master cylinder forming an atmospheric chamber, the diaphragm has an upper edge portion on the atmospheric chamber side that surrounds the flexible portion that covers the liquid level of the working fluid and is not in contact with the lower surface of the cap. A master cylinder characterized in that a rib is erected on the outer periphery of the flexible portion and inside the peripheral edge portion, the rib abutting the lower surface of the cap and having an outer peripheral surface abutting the inner peripheral surface of a protrusion protruding from the lower surface of the cap. reservoir.