JP3512221B2 - Reservoir for master cylinder - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As shown in FIG. 7, in a master cylinder reservoir, moisture and foreign matter are prevented from entering the reservoir chamber 1, and the reservoir chamber 1 is always maintained at approximately atmospheric pressure. In some cases, a diaphragm 4 is interposed between the tank body 2 and the cap 3, and the interior of the reservoir tank is divided into a reservoir chamber 1 and an atmosphere chamber 5 by the diaphragm 4.

That is, in such a reservoir, when the liquid level of the hydraulic fluid is lowered, the reservoir chamber 1 is expanded, and the chamber becomes negative pressure accordingly, but the diaphragm 4 is immediately deformed and displaced downward. , Reduce the volume of the reservoir chamber 1,
As a result, the pressure in the reservoir chamber 1 is maintained at approximately atmospheric pressure, and when the temperature rises, the air in the reservoir chamber 1 expands, which increases the pressure in the reservoir chamber 1, but the diaphragm 4 immediately deforms upward. Since the reservoir chamber 1 is displaced and expanded, the reservoir chamber 1 is maintained at approximately atmospheric pressure.

By the way, in the reservoir provided with the diaphragm 4 as described above, in order to make the diaphragm 4 respond to the entire range of the pressure change of the reservoir chamber 1, the diaphragm 4 which is considerably deformed and displaced is required. , A reservoir tank of a size that allows the amount of deformation / displacement of the diaphragm 4 is required.

Therefore, the slit 6 is formed at the center of the diaphragm.
When the pressure in the reservoir chamber 1 further increases or decreases after the diaphragm 4 reaches the upper limit or the lower limit, the above-mentioned shutoff valve is opened and the stop valve is opened from the reservoir chamber 1. The air is released into the atmosphere chamber 5, or the air is taken into the reservoir chamber 1 from the atmosphere chamber 5,
There is provided a reservoir in which the reservoir tank is maintained at about atmospheric pressure, and thus the size of the reservoir tank is reduced (for example, Japanese Utility Model Laid-Open No. 54-42881).

In such a diaphragm 4 of the reservoir, when the pressure in the reservoir chamber 1 further increases or decreases after the diaphragm 4 reaches the upper limit or the lower limit,
As shown in FIG. 8, the slit 6 forming portion of the diaphragm 4 is bent to open the slit 6.

[0007]

By the way, in such a reservoir, as shown in FIG. 7, the diaphragm 4 is sandwiched between the tank body 2 and the cap 3, and the cap 3 is screwed into the tank body 2. As a result, the diaphragm 4 is locked in the reservoir tank.

In such a reservoir, when the cap 3 is screwed into the tank body 2, a part of the diaphragm 4 may be rotated together with the cap 3. In such a case, the deformation area of the diaphragm 4 may be twisted, which may leave the slit 6 open. Of course,
In this case, the slit 6 does not serve as a closing valve.

Therefore, an object of the present invention is to provide a reservoir for a master cylinder that reliably keeps the slit closed when the diaphragm is not in operation.

[0010]

In the master cylinder reservoir of the present invention, a diaphragm having a slit in the center and an annular rib formed around the slit is sandwiched between the tank body and the cap, and the cap is provided. In a master cylinder reservoir in which the diaphragm is locked to a reservoir tank by being screwed into the tank body, a twist formed in a wavy shape in a circumferential direction in a deformation region between an annular rib and a peripheral portion of the diaphragm. It has an absorption part.

[0011]

In the reservoir for a master cylinder of the present invention, when the cap is fastened to the tank body, even if a part of the diaphragm is rotated together with the cap, the deformation of the diaphragm caused by the rotation is absorbed by the twist absorbing portion.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a master cylinder reservoir according to the present invention, and FIGS. 2 and 3 show a diaphragm adopted in the reservoir.

The master cylinder 10 has a reservoir 12 on the top of a cylinder body 11. Reservoir 1
The reservoir tank 13 forming the outer shell of 2 has an opening at the upper end, and is composed of a tank body 14 for containing the working fluid therein, and a cap 15 for closing the opening of the tank body 14. In the reservoir 12, the diaphragm 20 is sandwiched between the tank body 14 and the cap 15, and the diaphragm 20 divides the inside of the reservoir tank 13 into a reservoir chamber 16 and an atmosphere chamber 17.

The diaphragm 20 has a slit 21 at the center, which functions as a shutoff valve.
Around the circumference of 1, a C-shaped annular rib 22 is formed. The C-shaped annular rib 22 prevents the peripheral portion including the slit 21 from coming into close contact with the ceiling surface 15a of the cap 15, and the peripheral portion is deformed during the operation of the diaphragm 20, whereby the slit 21 is opened. It has a role to prevent it. Further, an annular rib 24 is formed slightly inside the attachment portion 23 on the peripheral edge of the diaphragm 20, and an annular rib 25 is further formed between the rib 24 and the annular rib 22. Then, as shown in FIG. 1, the inside of the annular rib 25 is formed flat. Further, between the annular rib 23 and the annular rib 24, as shown in FIG. 3, a twist absorbing portion 26 is formed in a wave shape in the circumferential direction. The twist absorbing portion 26 absorbs the deformation of the diaphragm 20 in the circumferential direction. Furthermore, in this embodiment, the contour lines of the waves constituting the torsional absorption portion 26, for example, the top portion 26a, the bottom portion 26b, etc., are waved in the radial direction, that is, in the circumferential direction, as shown in FIG. Formed into a shape, thereby
The main deformation portion 27 of the diaphragm 20 is configured.

In such a reservoir, the diaphragm 2
0 is sandwiched between the tank body 14 and the cap 15,
The diaphragm 20 is locked to the reservoir tank 13 by screwing the cap 15 onto the tank body 14.

At this time, even if a part of the diaphragm 20 is rotated together with the cap 15, the twist absorbing portion 26 of the diaphragm 20 absorbs the circumferential deformation. Further, the deforming portion 27 facilitates the displacement of the diaphragm 20 when the diaphragm 20 is largely displaced in the vertical direction due to the pressure difference between the reservoir chamber 16 and the atmospheric pressure chamber 17.

In the above embodiment, the twist absorbing portion 26
As shown in FIG. 2, the wave forming the (deformation part 27) is
Although the contour line is formed by one mountain, this wave may be formed in an S shape as shown in FIG. In this way, the deformation in the twisting direction (circumferential direction in FIG. 4) and the original deformation of the diaphragm 20 (perpendicular to the paper surface in FIG. 4) become easier.

Further, in any of the above embodiments, the twist absorbing portion 2
Although 6 and the deformed portion 27 are formed at the same location, they may be formed at different locations as shown in FIGS. 5 and 6. The diaphragm 20 shown in FIGS. 5 and 6 is
Between the annular rib 24 and the annular rib 25, a twist absorbing portion 26 having a wavy shape in the circumferential direction is formed, and the annular rib 2
As shown in FIG. 6, a main deforming portion 27 having a mountain shape in the radial direction is formed in the inner peripheral portion of No. 5.

[0019]

As described above, in the master cylinder reservoir according to the present invention, when the cap is fastened to the tank body, even if a part of the diaphragm is deformed by the turning force of the cap, the deformation is twisted. Since it is absorbed by the absorbing portion, it does not adversely affect the slit. Therefore, in the non-actuated state of the diaphragm, the slit is reliably maintained in the closed state.

[Brief description of drawings]

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

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

FIG. 3 is a vertical sectional view taken along the line AA of the diaphragm of FIG.

FIG. 4 is a plan view showing another embodiment of the diaphragm of the master cylinder reservoir according to the present invention.

FIG. 5 is a plan view showing yet another embodiment of the diaphragm of the master cylinder reservoir according to the present invention.

6 is a cross-sectional view taken along the line BB of the diaphragm of FIG.

FIG. 7 is a vertical cross-sectional view showing a conventional master cylinder reservoir.

FIG. 8 is a partial cross-sectional view showing an open state of a slit in a diaphragm of a conventional master cylinder reservoir.

[Explanation of symbols]

10 Master cylinder reservoir 12 reservoir 13 Reservoir tank 14 Tank body 15 caps 16 Reservoir chamber 17 atmosphere room 20 diaphragm 21 slits 22 Annular rib 23 Mounting part 24, 25 annular rib 26 Twist absorber 27 Deformation part

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B60T 11/26 B60T 17/06 B65D 51/16

Claims (3)

(57) [Claims] 1. A reservoir having a slit in the center and an annular rib formed around the slit is sandwiched between a tank body and a cap, and the cap is screwed into the tank body to store the diaphragm. A master cylinder reservoir to be locked in a tank, characterized in that a twist absorbing portion formed in a wavy shape in a circumferential direction is provided in a deformation area between the annular rib of the diaphragm and a peripheral edge portion. Reservoir. 2. The master cylinder reservoir according to claim 1, wherein the contour line of the twist absorbing portion is formed in a wave shape in the radial direction. 3. The reservoir for a master cylinder according to claim 1, wherein the contour lines of the twist absorbing portion are formed straight in the radial direction.