JPS5843482Y2 - master cylinder - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a master cylinder used in hydraulic brakes of automobiles and the like.

A master cylinder is usually constructed by connecting a reservoir to the top of the cylinder body so that fluid can be supplied, but the hydraulic fluid (brake fluid) stored in the reservoir can become contaminated with moisture when it comes into contact with air, causing early deterioration. The master cylinder is equipped with a moisture seal in the reservoir to isolate the stored hydraulic fluid from the atmosphere in order to prevent liquid leakage during rollover, and to prevent dust from entering from the atmosphere.
) has been proposed.

When this type of master cylinder is equipped with a liquid level alarm and a device liquid level detector to notify whether the amount of hydraulic fluid stored in the reservoir, that is, the liquid level is within a specified value,
As described in, for example, Japanese Utility Model Application No. 52-141585 and Japanese Utility Model Application No. 52139986, this detector was provided so as to be linked to the part of the moisture seal that was in contact with the liquid level and represented the level. .

However, with this configuration, if you do not remove the reservoir cap after filling the reservoir with hydraulic fluid to the specified level,
Due to the pressure difference acting on both sides of the moisture seal, the moisture seal part moves to follow the liquid level so that it is always in contact with the liquid level, so although the liquid level detector functions normally, once the cap is opened, Once atmospheric pressure is introduced, the pressure difference between the two sides of the moisture seal disappears and the moisture seal moves upward, so even when the cap is closed next time, the moisture seal can no longer come into contact with the lowered liquid level. Since it moves with a large gap between it and the surface, the liquid level detector cannot function properly.

Therefore, in order to eliminate the need to link the liquid level detector to the moisture seal part,
As disclosed in the above publication, a configuration has also been proposed in which a float that floats on the stored hydraulic fluid is provided in the reservoir and a liquid level detector is attached to this float.

However, with this configuration, it is not possible to provide a filter for removing foreign matter mixed in when the hydraulic fluid is injected into the reservoir, and the only way to remove the mixed foreign matter is with a filter provided at the hydraulic fluid outlet of the reservoir.

However, if a filter is provided at the hydraulic fluid outlet of the reservoir in this way, cleaning the filter becomes extremely troublesome, and in the worst case scenario, it is expected that the reservoir will have to be removed from the cylinder body to clean the filter.

From the above points of view, the present invention provides a float with a liquid level detector that is suspended above the storage operating source in the reservoir, but the float is made thick enough to cover almost the entire surface of the liquid.
In addition, the present invention proposes an improved master cylinder in which an opening is formed in the float and a filter is provided in the opening so that the liquid level detector can always function normally and the filter can be easily cleaned. It is.

The invention will now be described in detail with reference to the illustrated embodiments.

Figures 1 to 3 show an example of the configuration of the master cylinder of the present invention when the reservoir is box-shaped. , 4 is a boss portion of the cylinder body 1 which also serves as a liquid supply port.

Reference numeral 5 indicates a reservoir whose upper part is entirely open, and 6 indicates a lid that closes the upper opening.The reservoir 5 has a boss part 7 at its bottom that also serves as a liquid outlet, and these boss parts are connected through an elastic grommet 8. The reservoir 5 is attached to the cylinder body 1 by liquid-tightly fitting it into the boss portion 4.

As clearly shown in FIGS. 2 and 3, the lid 6 is attached with one side edge hinged to the corresponding side edge of the reservoir 5 with a pin 9, thereby allowing the lid 6 to be opened and closed.

The closed position of the lid body 6 can be restrained by a normal releasable clamp 10, and when the lid body 6 is in the closed position, a peripheral edge of a moisture seal 11 is formed between the opening edge of the reservoir 5 and the inner surface of the lid body 6. This moisture seal 11 is disposed within the reservoir 5 by applying pressure to the moisture seal 11a.

In the present invention, the float 13 floating on the hydraulic fluid 12 stored in the reservoir 5 is removably inserted into the reservoir from the upper opening of the reservoir 5, and is designed to cover the entire surface of the hydraulic fluid. Bottom 1 of seal 11
1b, and provided in the reservoir 5.

A permanent magnet 14 as a liquid level detector is fixed at the center of the float 13, and a reed switch 15, which closes when the permanent magnet 14 approaches, is embedded in a partition wall 5a protruding from the inner surface of the bottom wall of the reservoir 5. .

The float 13 is further provided with openings 13a penetrating between its upper and lower surfaces, and a net-shaped filter 16 is provided in the float 13 so as to cross each of these openings.

An atmospheric communication hole 6a is formed in the lid 6, and a cap 1T is detachably placed over the hole 6a so as not to block the hole 6a.

Thus, the cavity 18 whose bottoms are closed by the lid 6 and the moisture seal 11 is always open to the atmosphere through the hole 6a, and the remaining cavity in the reservoir 5 (the cavity filled with the working fluid 12) is filled with the moisture seal 11. isolated from the atmosphere by
Atmospheric pressure is applied to the liquid level to enable liquid replenishment to the master cylinder side.

In the tandem master cylinder of the present invention having the above-described structure, the moisture seal 11 completely isolates the hydraulic fluid filling space in the reservoir 5 as described above, and prevents moisture from entering the hydraulic fluid 12 due to contact with air. Deterioration can be prevented, leakage of the hydraulic fluid 12 due to rollover can be prevented, and dirt and the like can be prevented from entering the hydraulic fluid.

When the liquid level of the hydraulic fluid 12 decreases, the float 13 descends accordingly, and when the liquid level falls below a specified value, the permanent magnet 14 provided on the float 13 closes the reed switch 15. As a result, the liquid level alarm device can be activated to warn of a drop in the liquid level.

Note that when the liquid level drops, the bottom part 1 of the moisture seal 11
1b is the pressure difference that occurs on both sides of the moisture seal,
The float 13 is always maintained in the state shown in the first figure in contact with the float 13 and lowered in one piece, but at this time, once the lid 6 is opened, atmospheric pressure is introduced into the hydraulic fluid filling space in the reservoir 5. Even when the lid body 6 is closed thereafter, the moisture seal bottom portion 11b is located above the float 13 with a distance therebetween.

However, even in this case, the float 13 floats on the surface of the hydraulic fluid 12 and accurately detects the level, and the permanent magnet 14
By closing the reed switch 15 at , it is possible to warn of a drop in the liquid level.

Here, when replenishing the reservoir 5 with hydraulic fluid, the lid 6 is opened and the moisture seal 11 is removed.

During this operation, the replenishment hydraulic fluid enters the reservoir 5 through the filter 16, and the filter 16 reliably removes any foreign matter contained in the hydraulic fluid.

If the filter 16 is dirty, take it out from the upper opening of the reservoir 5 together with the float 13,
The filter 16 can be cleaned without difficulty.

Note that when the reservoir 5 has a shape other than the box shape described above, the shapes of the moisture seal 11 and the float 13 are naturally determined to correspond to this shape, but an example of a configuration when the reservoir 5 is cylindrical is are shown in FIGS. 4 and 5.

In this example as well, by basically adopting the same configuration as in the above-described example, it is possible to achieve the same effects as described above, but the opening 13 provided in the float 13
For example, as shown in FIG. 5, there are four filters a, which are preferably arranged at equal intervals in the circumferential direction, and the filter 16 is provided on the float 13 so as to cross each opening 13a.

[Brief Description of the Drawings] Figure 1 is a cutaway side view of essential parts of the master cylinder of the present invention, Figure 2 is a plan view thereof, Figure 3 is a sectional view taken along line A-A in Figure 2, and Figure 4 is a main part of the master cylinder of the present invention. A sectional view of a reservoir showing another example of the invention,
FIG. 5 is a plan view of a float to be provided in the reservoir shown in FIG. 4. 1... Cylinder body, 2... Liquid supply port, 3... Relief port, 4, 7...
...Boss part, 5...Reservoir, 6...
Lid body, 6a... Atmospheric communication hole, 8... Elastic grommet, 9... Pin, 10...
Clamp, 11... Moisture seal, 12
......Hydraulic fluid, 13...Float, 13
a...Opening, 14...Permanent magnet, 15
...Reed switch, 16...Filter 17...Cap.

Claims (1)

[Scope of utility model registration request] In the master cylinder, which has a reservoir coupled to the upper part of the cylinder body so as to be able to supply liquid, and a moisture seal is provided in the reservoir, the upper part of the reservoir is entirely opened and the upper opening is covered with a lid body that can be opened and closed. , between the liquid level in the reservoir and the moisture seal, the liquid level detector is inserted removably into the reservoir from the upper opening to cover almost the entire surface of the liquid level, and has a liquid level detector of a liquid level alarm device. A master cylinder characterized in that a float is inserted, an opening is formed in the float, and a filter is provided across the opening.