JP2505549Y2 - Reservoir for master cylinder - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master cylinder reservoir, and more particularly to an improvement of a diaphragm installed in the reservoir.

[0002]

2. Description of the Related Art A master cylinder reservoir has a diaphragm interposed between the reservoir body and the cap in order to prevent moisture and foreign matter from entering the reservoir chamber and to keep the reservoir chamber at almost atmospheric pressure. Some of them are mounted in a reservoir chamber and an atmosphere chamber is defined by the diaphragm.

That is, in such a reservoir, when the liquid level of the working fluid is lowered, the reservoir chamber is expanded and the chamber becomes negative pressure accordingly, but the diaphragm is immediately deformed / displaced downward to cause the reservoir. When the volume of the chamber is reduced, thereby keeping the pressure in the reservoir chamber at about atmospheric pressure, and when the temperature rises, the air in the reservoir chamber expands, which increases the pressure in the reservoir chamber, but the diaphragm immediately rises. The reservoir chamber is maintained at approximately atmospheric pressure because it is deformed / displaced to and is expanded.

[0004]

By the way, in the reservoir provided with the diaphragm as described above, in order to make the diaphragm respond to the entire range of the pressure change of the reservoir chamber, the amount of deformation and displacement is considerably large. A diaphragm,
A reservoir tank having a size that allows the deformation and displacement of the diaphragm is required.

Therefore, when a slit is formed in the center of the diaphragm to form a stop valve there, and when the pressure in the reservoir chamber further increases or decreases after the diaphragm reaches the upper limit or the lower limit, the stop valve described above is used. Open the chamber to release air from the reservoir chamber to the atmospheric chamber or take air from the atmospheric chamber into the reservoir chamber so that the reservoir chamber is maintained at approximately atmospheric pressure, thus providing a reservoir with a miniaturized reservoir tank. (For example, the actual exploitation 54-4
2881).

In such a reservoir diaphragm,
When the pressure in the reservoir chamber further increases or decreases after the diaphragm reaches the upper limit or the lower limit, as shown in FIG. 5, the slit forming portion of the diaphragm a bends to open the slit b.

However, in such a diaphragm, as is clear from the figure, when the slit b is opened on the outer surface on the projecting side, but the inner surface is kept in contact, the air is not sufficiently circulated. In such a case, the reservoir chamber cannot be brought to almost atmospheric pressure.

Therefore, an object of the present invention is to provide a master cylinder reservoir in which the reservoir tank can be downsized and the pressure in the reservoir chamber can be reliably maintained at atmospheric pressure.

[0009]

The master cylinder reservoir of the present invention comprises a diaphragm that moves up and down as the pressure in the reservoir chamber increases and decreases to maintain the reservoir chamber at approximately atmospheric pressure, and further, in the center of the diaphragm, In the master cylinder reservoir in which the diaphragm has reached the upper limit or the lower limit, and when the pressure in the reservoir chamber increases or decreases, a slit is formed to maintain the reservoir chamber at substantially atmospheric pressure. First to surround
And forming a second annular rib so as to surround the rib with an appropriate distance from the rib, and at a position reaching the movement limit of the diaphragm,
A stopper that is in contact with the first and second annular ribs is provided in the reservoir tank, and the first and second annular rings are operated by the differential pressure acting on the upper and lower surfaces of the diaphragm as the pressure in the reservoir chamber increases and decreases. The rib comes into contact with the stopper, and the differential pressure causes the first of the diaphragm to move.
The second annular rib is bent between the second annular rib and the peripheral portion of the slit is pulled toward the first annular rib to open the slit.

[0010]

In the master cylinder reservoir according to the present invention, the first and second annular ribs come into contact with the stopper due to the differential pressure acting on the upper and lower surfaces of the diaphragm as the pressure in the reservoir chamber increases and decreases, and the differential pressure causes the first and second annular ribs to abut. The diaphragm is bent between the first and second annular ribs, whereby the peripheral portion of the slit is pulled toward the first annular rib to open the slit.

[0011]

1 to 3 show the essential parts of an oil reservoir according to the present invention.

FIG. 1 shows a master cylinder reservoir according to the present invention, and FIGS. 2 and 3 show a diaphragm adopted in the reservoir.

This master cylinder has a cylinder body 1
A reservoir 2 is provided on the upper part of the. A reservoir tank 3 forming an outer shell of the reservoir 2 has an opening at its upper end, and is composed of a tank body 4 for containing a working fluid therein, and a cap 5 for closing the opening of the tank body 4. In the reservoir 2, the diaphragm 6 is sandwiched between the tank body 4 and the cap 5 via the retainer ring 7, and the inside of the reservoir tank 3 is divided into the reservoir chamber 8 and the atmosphere chamber 9 by the diaphragm 6. Well defined.

A float 11 guided vertically by a guide 10 formed in the tank body 4 is arranged in the reservoir chamber 8, and an atmosphere chamber 9 is formed at the upper end of the retainer ring 7. Groove 7a and tank body 4
It is open to the outside (atmosphere) through an annular gap 12 formed between the cap 5 and the cap 5 and a notch 4a formed in the upper edge of the tank body 4.

As shown in FIG. 1, the diaphragm 6 is continuous with a deformed portion 6b which is curved and projected upward, and an inner end edge of the deformed portion 6b slightly inward from the peripheral mounting portion 6a. It is formed of a flat bottom portion 6c. This bottom 6
A slit 6d having a function as a shutoff valve is provided at the center of c.
Are formed. Further, as shown in FIG. 2, a C-shaped first rib 6e and a second rib 6f surrounding the slit 6d are formed on the upper surface of the bottom portion 6c, and the discontinuous portion 6g of the rib 6e is formed. A plurality of protrusions 6i are formed in a straight line in a space from to the discontinuous portion 6h of the rib 6f.
The C-shaped rib 6e prevents the peripheral portion including the slit 6d from coming into close contact with the lower surface 5a of the cap 5, and prevents the peripheral portion from being deformed during the operation of the diaphragm 6 and thereby opening the slit 6d. It has a role to play.

In such a master cylinder reservoir 2, when the pressure in the reservoir chamber 8 rises, the diaphragm 6 in the state shown in FIG. 4a is deformed / displaced upward so that the ribs 6e, 6f form the cap 5. It hits the lower surface (stopper) 5a. Further, when pressure acts on the diaphragm 6, the fourth
The portion A between the ribs 6e and 6f is deformed upward as shown in FIG. Along with this, the peripheral portion of the slit 6d is pulled in the arrow direction, and as a result, the slit 6d is expanded. At this time, the bottom portion 6c of the diaphragm 6 other than the vicinity of the slit 6d may come into contact with the lower surface 5a of the cap 5 to cut off the communication between the slit 6d and the outside. , Ribs 6e, 6f discontinuous portion 6g,
An air passage is secured by 6h and the protrusion 6i.

Although the present invention has been described in principle in the above embodiments, the rib 6f is made thicker than the rib 6e depending on the material and shape of the diaphragm 6, and the rib 6f is increased. It is preferable to further increase the expansion effect of the slit 6d by reducing the deformation of the above or making the height of the rib 6e higher than that of the rib 6f.

Further, in the above embodiment, the ribs 6e and 6f are formed on the upper surface of the diaphragm 6, but these ribs 6e and 6f are formed on the lower surface of the diaphragm 6 and the ribs 6e and 6f are formed on the diaphragm 6. The slit 6d may be expanded by abutting against the float 11 or the like as a stopper at the lower limit position.

[0019]

As described above, in the master cylinder reservoir according to the present invention, the force in the direction of pulling the periphery of the slit acts on the upper limit or the lower limit position of the diaphragm, so that the slit is reliably opened. Therefore, in this reservoir, even if it is downsized, the reservoir chamber is always kept at about atmospheric pressure.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a master cylinder having a reservoir according to the present invention.

2 is a plan view showing a diaphragm of the reservoir of FIG. 1. FIG.

3 is a vertical cross-sectional view of the diaphragm of FIG.

FIG. 4 is a partially enlarged cross-sectional view illustrating the operation of the diaphragm of the reservoir according to the present invention.

FIG. 5 is a partial cross-sectional view showing an open state of a slit in a conventional diaphragm.

[Explanation of symbols]

 1 Cylinder body 2 Reservoir 3 Reservoir tank 4 Tank body 4a Notch 5 Cap 6 Diaphragm 6a Mounting part 6b Deformation part 6c Bottom part 6d Slit 6e, 6f Rib 6g, 6h Discontinuous part 6i Projection 7 Retainer ring 7a Groove 8 Atmosphere chamber 10 Guide 11 Float 12 Gap

Claims (2)

(57) [Scope of utility model registration request] 1. A diaphragm, which moves up and down as the pressure in the reservoir chamber increases and decreases to maintain the reservoir chamber at substantially atmospheric pressure, further comprising a diaphragm in the center of the diaphragm which has reached an upper limit or a lower limit. In a master cylinder reservoir in which a slit is formed to open and maintain the reservoir chamber at approximately atmospheric pressure when the pressure in the reservoir chamber increases or decreases, a first annular rib is formed so as to surround the slit, and A second annular rib is formed so as to surround the rib at an appropriate distance from the rib, and a stopper that comes into contact with the first and second annular ribs is provided in the reservoir tank at a position where the movement limit of the diaphragm is reached. And the differential pressure acting on the upper and lower surfaces of the diaphragm as the pressure in the reservoir chamber increases and decreases,
The first and second annular ribs come into contact with the stopper, and the differential pressure further bends the diaphragm between the first and second annular ribs, thereby causing the peripheral portion of the slit to have the first portion. A master cylinder reservoir characterized in that the slit is opened by pulling in the direction of the annular rib. 2. The first and second annular ribs are formed in a C shape, and a plurality of them are provided between the discontinuous portion of the first annular rib and the discontinuous portion of the second annular rib. 2. The master cylinder reservoir according to claim 1, wherein the protrusions are linearly scattered.