JPH0445979Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a reservoir for a vehicle hydraulic master cylinder that operates the brakes and clutches of vehicles using hydraulic pressure. This invention relates to a structure for preventing leakage of hydraulic fluid.

[Conventional technology]

As shown in FIG. 4, this type of reservoir used in a hydraulic master cylinder has a diaphragm 1 that follows the liquid level of the hydraulic fluid and prevents the generation of bubbles.
The flange portion 1a is placed between the mouth edge 2a of the liquid storage chamber 2 and the cap 3 attached to the mouth edge 2a, and the side wall portion 1b continuous to the flange portion 1a is placed between the mouth edge 2a of the liquid storage chamber 2. The diaphragm 1 and the cap 3 are sandwiched between the inner circumferential wall 2b and a protrusion 3a provided on the lower surface of the cap 3.
An atmospheric chamber 4 that communicates with the outside via an atmospheric communication hole 3b formed in the cap 3 is defined.

Since the diaphragm 1 is always immersed in the liquid level as described above, the hydraulic fluid F permeates the diaphragm and accumulates on the upper surface, and when the vehicle body is tilted, this leaks to the outside from the atmosphere communication hole 4a and spreads around the reservoir. Because there is a risk of contaminating the atmosphere or clogging the air communication hole 4a, the applicant has previously proposed
The technology disclosed in Publication No. 159263 was presented.

In this technology, a diaphragm plate interposed between the cap and the diaphragm is caulked and fixed to the underside of the cap, and a first atmospheric chamber communicating with the outside is created between the cap and the diaphragm plate, and a first atmospheric chamber is created between the diaphragm plate and the diaphragm. Two atmospheric chambers are defined, and both atmospheric chambers are communicated with each other through a vent hole drilled in the diaphragm plate.The hydraulic fluid that has permeated the top surface of the diaphragm is transferred to the second atmospheric chamber by the diaphragm plate that covers the top. kept in
This prevents the staining and clogging mentioned above.

[Problem to be solved by the invention] The diaphragm 1 installed as described above is
When a strong tightening torque is applied to the screws that fix the cap 3, the flange 1a and the side wall 1b are pulled inward by the protrusions 3a, as shown in FIG. 5, and the flange 1a becomes liquid storage. There was a risk that it would fall into the chamber 2 and the sealing performance of the diaphragm 1 would be impaired.

The present invention was developed against this background, and provides a reservoir for a vehicle hydraulic master cylinder that uses a diaphragm plate to improve the sealing performance of the diaphragm and further prevent leakage of hydraulic fluid. The purpose is to

[Means to solve the problem]

In order to achieve the above object, in a reservoir for a vehicle hydraulic master cylinder, a flange portion of a diaphragm is sandwiched between an opening edge of a fluid storage chamber that stores hydraulic fluid and a cap that is fitted to the opening edge, and a diaphragm plate is interposed between the cap and the diaphragm to define a first atmospheric chamber that communicates with the outside between the cap and the diaphragm plate and a second atmospheric chamber between the diaphragm plate and the diaphragm, and both atmospheric chambers communicate with each other through an air hole drilled in the diaphragm plate, the inner periphery of the opening of the fluid storage chamber is formed into a tapered surface, and the diaphragm plate is provided with:
The diaphragm is provided with a tapered edge that clamps it against the tapered surface of the liquid storage chamber, a rib is provided on the upper surface that abuts against the lower surface of the cap and biases the diaphragm plate toward the liquid storage chamber, and the air vent is formed in the center of the diaphragm plate.

[Effect]

According to the above configuration, when the cap is attached, the edge of the diaphragm plate, which is pressed by the rib that comes into contact with the lower surface of the cap, clamps the diaphragm between the tapered surface of the liquid storage chamber. The pressing force of the edge acts in the direction of expanding the diaphragm toward the outer periphery, and the diaphragm is compressed without being drawn into the liquid storage chamber. This improves the sealing performance of the diaphragm and connects the liquid storage chamber with the first and second The airtightness of the atmospheric chamber is reliably maintained.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

The hydraulic master cylinder 10 is a brake master cylinder that hydraulically operates the front brake of a bar handle vehicle such as a motorcycle or tricycle. A reservoir 13 for storing a working fluid F is integrally formed in the fluid storage chamber 12.

A piston 16, which generates pressure fluid in the bottom hydraulic chamber 15 when the brake lever 14 is pushed, is inserted into the cylinder hole 11a, which is opened at the rear of the cylinder body 11, in a fluid-tight and movable manner. The inclined partition wall 11b that defines the cylinder hole 11a and the liquid storage chamber 12 has a relief port 17 and a supply port 18 for supplying the hydraulic fluid F in the liquid storage chamber 12 to the cylinder hole 11a. is drilled.

The reservoir 13 includes an opening 12a of the liquid storage chamber 12.
A cap 19 is attached to the cap 19 with screws 20, and a flange 21a of a diaphragm 21 is clamped between the mouth edge 12a and the cap 19. , the diaphragm plate 22 is caulked and fixed.

The gap between the cap 19 and the diaphragm 21 is
It is divided into two upper and lower chambers by the interposition of the diaphragm plate 22, with a first atmospheric chamber 23 between the cap 19 and the diaphragm plate 22, and a second atmospheric chamber 24 between the diaphragm plate 22 and the diaphragm 21.
The first atmospheric chamber 23 communicates with the outside through an atmospheric communication hole 19b formed in the cap 19, and the first and second atmospheric chambers 23 and 24 are connected to the center of the diaphragm plate 22. It communicates through a ventilation hole 22a formed in the.

The inner circumferential wall 12b of the liquid storage chamber 12 is formed with a tapered surface that gradually widens toward the mouth edge 12a due to a mold release draft provided in the mold.
A tapered surface 12c having a larger slope than the inner circumferential wall 12b is formed on the inner periphery of the opening of the opening 2b.

The diaphragm 21 includes the above-mentioned mounting flange portion 21a, a tapered side wall portion 21b laid on the tapered surface 12c, and a plate-shaped liquid surface contact portion 21c that follows changes in the liquid level of the hydraulic fluid F. , the liquid surface contact portion 2 concentrically surrounds the liquid surface contact portion 21c.
A bellows portion 21d is provided that allows vertical movement of 1c.

A pair of ribs 21 are provided on the upper surface of the liquid surface contact portion 21c.
e, 21e are spaced apart and protrude, and both ribs 2
1e and 21e act as spacers between the liquid surface contact portion 21c and the diaphragm plate 22, and maintain the required volume of the second atmospheric chamber 24 even when the liquid level is shaken due to the tilt of the reservoir 13 or vibrations caused by running. In addition, in order to prevent the liquid surface contact portion 21c from adhering to the diaphragm plate 22, the ventilation hole 22a is not blocked.

The diaphragm plate 22 is a plate-shaped body made of synthetic resin that is meterable and impermeable to the hydraulic fluid F, and the vent hole 22a is located in the center of the diaphragm plate 22, and the caulking protrusion 1 is connected to the diaphragm plate 22.
The diaphragm plate 22 is provided continuously with the mounting hole 22b through which the diaphragm plate 9a is inserted, and horse-shoe-shaped ribs 22c, 22c are provided on the upper surface of the diaphragm plate 22 so as to protrude from each other and face each other in the longitudinal direction of the diaphragm plate 22, with the ventilation hole 22a and the mounting hole 22b in between. The protrusion 19a inserted into the mounting hole 22b
When the diaphragm plate 22 is fixed to the cap 19 by caulking, the ribs 22c, 22c come into contact with the lower surface of the cap 19, and the required gap of the first atmospheric chamber 23 is secured.

An edge 22d is formed on the outer periphery of the lower surface of the diaphragm plate 22, and the diaphragm plate 22 and the cap 19 are attached to the liquid storage chamber 22d at both ends.
2, the semicircular fitting groove 22 is fitted into the boss 12d for attaching the cap of the liquid storage chamber 12.
e, 22e are recessed. The above edge 22d
The lower outer peripheral surface 22f is formed in a tapered shape with the same slope as the tapered surface 12c formed on the inner periphery of the mouth of the liquid storage chamber 12, and the cap 19 to which the diaphragm plate 22 is fixed is screwed into the liquid storage chamber 12. When stopped, the edge 22d is pressed by the ribs 22c, 22c that come into contact with the lower surface of the cap 19, and presses the side wall 21b of the diaphragm 21 between it and the tapered surface 12c of the liquid storage chamber 12.

The pressing force of the edge portion 22d acts in a direction to expand the side wall portion 21b toward the outer circumference, and the diaphragm 21 is compressed without being drawn into the liquid storage chamber 12 as in the conventional case, so the sealing performance of the diaphragm 21 is improved. However, together with the mouth edge 12a and the flange 21a that is clamped to the cap 19, the liquid storage chamber 12 and the first,
The airtightness of the second atmospheric chambers 23 and 24 is reliably maintained.

In addition, a ventilation hole 2 that communicates both atmospheric chambers 23 and 24 is provided.
2a is provided in the center of the diaphragm plate 22, so even if the reservoir 13 is tilted in any direction on a slope or bank, the vent hole 22a will be located far from the liquid surface, so that no leakage will occur on the liquid surface contact part 21c. The discharged hydraulic fluid F is less likely to come out from the vent hole 22a to the first atmospheric chamber 23, thereby preventing clogging of the atmospheric communication hole 19b and leakage to the outside.

Furthermore, in this embodiment, one of the ribs 22c is located between the ventilation hole 22a and the atmospheric chamber communication hole 19b.
2a, so that even if the working fluid F should come out from the vent hole 22a to the first atmospheric chamber 23, the rib 22c acts as a barrier and does not allow easy leakage.

In the above embodiment, in order to obtain more reliable sealing performance of the diaphragm, the tapered surface on the inner periphery of the liquid storage chamber opening was formed separately from the draft taper formed on the inner peripheral wall. In the present invention, it is also possible to utilize the draft taper by extending it to the inner periphery of the mouth.

Further, although the desired purpose of the edge of the diaphragm plate can be achieved by forming only the outer circumferential surface into a tapered shape as in the embodiment, the same effect can be achieved even if the entire edge is formed into a tapered shape.

[Effect of idea]

As described above, in the reservoir of the present invention, the inner periphery of the mouth of the liquid storage chamber is formed into a tapered surface, and a diaphragm plate that defines the first and second atmospheric chambers is interposed between the cap and the diaphragm. , the diaphragm plate is provided with a tapered edge that clamps the diaphragm against the tapered surface of the liquid storage chamber, and the upper surface is in contact with the lower surface of the cap to urge the diaphragm plate toward the liquid storage chamber. Because the diaphragm is provided with a protruding rib, the diaphragm is compressed between the tapered surface of the liquid storage chamber and the edge of the diaphragm plate, without being drawn into the liquid storage chamber as in the conventional case, improving the sealing performance of the diaphragm. Thus, the airtightness of the liquid storage chamber and the first and second atmospheric chambers can be maintained reliably.

In addition, a vent hole that communicates both atmospheric chambers is drilled in the center of the diaphragm plate, so that even if the reservoir is tilted in either direction when the vehicle body is tilted, the vent hole will be located far from the liquid level and The hydraulic fluid seeping out onto the upper surface of the diaphragm is more difficult to leak into the first atmospheric chamber, thereby preventing leakage to the outside and clogging of the atmospheric communication hole.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention,
Figure 1 is a partially cutaway front view of the hydraulic master cylinder, Figure 2 is a perspective view of the diaphragm plate, Figure 3 is an enlarged front view of the main parts of the reservoir, and Figures 4 and 5.
Each figure is an enlarged front view of a main part of a reservoir showing a conventional example. 10... Hydraulic pressure master cylinder, 11... Cylinder body, 12... Liquid storage chamber, 12a... Mouth edge,
12b...Inner peripheral wall, 12c...Tapered surface, 13...
... Reservoir, 19 ... Cap, 19a ... Protrusion, 19b ... Atmospheric communication hole, 21 ... Diaphragm, 21a ... Flange part, 21b ... Side wall part,
21c...Liquid surface contact part, 22...Diaphragm plate, 22a...Vent hole, 22b...Mounting hole, 22c...Rib, 22d...Edge, 22e...
...Fitting groove, 22f... Outer peripheral surface, 23... First atmospheric chamber, 24... Second atmospheric chamber, F... Working fluid.

Claims (1)

[Scope of utility model registration request] The flange portion of the diaphragm is clamped between the mouth edge of a liquid storage chamber that stores working fluid and a cap attached to the mouth edge, and a diaphragm plate is interposed between the cap and the diaphragm. , between the cap and the diaphragm plate, a first
In the reservoir of a hydraulic master cylinder for a vehicle, the atmospheric chamber is defined by a second atmospheric chamber between a diaphragm plate and a diaphragm, and both atmospheric chambers are communicated with each other through a vent hole drilled in the diaphragm plate. The inner periphery of the mouth portion is formed into a tapered surface, and the diaphragm plate is provided with a tapered edge portion that clamps the diaphragm with the tapered surface of the liquid storage chamber, and the upper surface is in contact with the lower surface of the cap, so that the diaphragm plate 1. A reservoir for a hydraulic master cylinder for a vehicle, characterized in that a rib is protrudingly provided to urge the plate toward the liquid storage chamber, and the vent hole is formed in the center of the diaphragm plate.