JPS581394Y2 - Master cylinder reservoir - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a brake fluid reservoir attached to a mask cylinder of an automobile brake system, to which a fluid level switch is added.

Conventionally, in order to ensure that there is sufficient brake fluid in the reservoir for brake safety reasons, it is activated when the fluid level in the reservoir is below a predetermined minimum allowable height. A liquid level switch is installed to alert the driver.

However, with a reservoir that is long in the longitudinal direction of the vehicle body, such as the integrated reservoir common to both brake systems in tandem mask cylinders, when the vehicle suddenly starts or brakes, the brake fluid inside the reservoir will be transferred to one side of the reservoir in the longitudinal direction of the vehicle body. The liquid level switch would malfunction and give a false alarm to the driver, causing more anxiety than necessary.

The purpose of this invention is to prevent the fluid level switch from malfunctioning by preventing sudden changes in the level of the brake fluid in the reservoir where the fluid pressure switch is located, even in such a case.

The configuration of this invention will be explained by way of embodiments with reference to the drawings.

2 is the cylinder body of a tandem master cylinder with two brake systems, and a single cylinder hole 4.
The cylinder axis is defined in the longitudinal direction of the vehicle, with the front direction in the direction of travel of the vehicle being the front direction of the vehicle body, and the rear direction in the direction of travel being the rear direction of the vehicle body.

) and can be attached to the vehicle body.

The side wall of the cylinder hole 4 has supply ports 6 and 8 for replenishing brake fluid into the cylinder hole 4, return ports 10 and 12 for returning brake fluid from the cylinder hole 4, and discharges brake fluid to a wheel cylinder (not shown). Discharge ports 14 and 16 are provided.

Reference numeral 18 denotes a brake fluid reservoir, which is fluid-tightly fitted into recesses 20 and 22 communicating with the supply ports 6 and 8 and the return ports 10 and 12, and coupled to the cylinder body 2.

Reference numeral 24 indicates a welding mark, and since the internal shape of the reservoir 18 is complicated, the upper and lower parts of the reservoir 18 are previously molded separately and welded together.

The reservoir 18 comprises an outer wall 25, and inside thereof there is a cylindrical surrounding wall 30 extending in the vertical direction of the vehicle body, and a dividing wall 2 provided on a temporary plane passing through the central axis and perpendicular to the longitudinal direction of the vehicle body.
6.28 forms liquid chambers 32, 34 outside the surrounding wall 30 and a liquid chamber 36 inside the surrounding wall 30.

The liquid chamber 32 is located in the recess 20. Supply port 6. In the brake system of the return port 10 and the discharge port 14, the liquid chamber 34 is located in the recess 22. Supply port 8. Brake fluid to be supplied to the brake system at the return port 12 and the discharge port 16 is stored.

Reference numeral 38 denotes a liquid level switch provided in the liquid chamber 36, which is fitted into a portion extending upward from the surrounding wall 30 to the reservoir 18, and a float having a permanent magnet 42 on the inner periphery is fitted around the lower mandrel 40. The child 44 is provided to slide up and down depending on the liquid level height of the liquid chamber 36.

Although not shown, a reed switch is provided inside the mandrel 40, and when the liquid level in the liquid chamber 36 is below a predetermined minimum allowable height, the reed switch is activated by the magnetic force of the permanent magnet 42. Then, a warning is given to the driver via the electric wire 46 extended to the outside of the liquid level switch 38.

At the connecting portions of the dividing walls 26 and 28 with the surrounding wall 30, there are narrow grooves 48 and 5 whose lower end height is the above-mentioned minimum allowable height.
0, and similar narrow grooves 52, 54 are provided at the connection portions of the surrounding wall 30 with the dividing walls 26, 28.

Therefore, the brake fluid supplied to the fluid chamber 36 is
2.54 and is also stored in the liquid chambers 32 and 34.

The operation of this embodiment will be explained.

When the vehicle is stopped on a horizontal road or is traveling at a constant speed on a horizontal road, the level of the brake fluid in the reservoir 18 is parallel to the cylinder axis and horizontal.

At this time, if the brake fluid level in the reservoir 18 is higher than the minimum allowable height, the brake fluid in each fluid chamber 32, 34, and
．． 52, 54, and moves between each liquid chamber 32, 34, 36, and the liquid level in each liquid chamber 32, 34, 36 is at the same height and horizontal.

In this case, if one of the systems, for example the system for the liquid chamber 32, fails and the liquid level in the liquid chamber 32 drops to below the minimum allowable height, the liquid in the other liquid chambers 34, 36 The surface height is brought to the minimum allowable height by movement of the brake fluid through the slots 48, 50, 52, 54.

Then, the alarm switch 38 is activated to alert the driver, but the minimum allowable height of the fluid chamber 34 remains, that is, the minimum amount of brake fluid necessary to operate the brakes of the systems in the fluid chamber 34 that are not malfunctioning. .

When an automobile suddenly starts or brakes suddenly without a malfunction, the liquid level in each of the liquid chambers 32, 34, and 36 suddenly and greatly tilts with respect to the cylinder axis due to the inertial force acting on the brake fluid.

Then, the brake fluid passes through the grooves 48, 50, 52, 54 and gradually fills each fluid chamber 32, 34, 36 due to the throttling effect.
However, the size of the dividing grooves 48, 50, 52, and 54 is determined to be an appropriate size so that the amount of brake fluid that moves while the car is running is as small as possible (therefore, the size of the dividing grooves 48, 50, 52, and A small passage of any shape and size can be used in place of the groove.

). Also, when the car starts or brakes particularly suddenly,
The brake fluid in the reservoir scatters to the vicinity of the inner surface of the upper end wall, but when the scattered brake fluid also moves between the respective fluid chambers 32, 34, and 36, it passes through the dividing grooves 4B, 50, 52, and 54, and its throttling effect gradually move.

From the above explanation, this invention has the following effects.

(1) When a car suddenly starts or brakes, does the movement of brake fluid between the fluid chamber within the surrounding wall and other fluid chambers cause the brake fluid to scatter due to the throttling effect of the small passage? Regardless of the situation, it will not occur suddenly and the alarm switch will not malfunction.

(2) Since the inertial force acting on the brake fluid acts at right angles to the direction of passage of the brake fluid that attempts to move between the fluid chamber in the surrounding wall and other fluid chambers through the small passage, This inertia effect on the movement of brake fluid is avoided, the movement of the fluid is slow, and the alarm switch does not malfunction.

(3) Since the enclosure wall has been extended from the bottom wall of the reservoir to the top edge, when installing or removing the alarm switch, the alarm switch will not reach the upper end of the enclosure wall, as would be the case if the enclosure wall was only extended halfway. Or, it will not be damaged by hitting the upper end wall of the reservoir inward.

(4) Since the dividing wall extends from the bottom wall of the reservoir to the top wall, even if brake fluid splashes to the inner surface of the top wall of the reservoir, it will not spread between the fluid chambers outside the surrounding wall. Since no movement of brake fluid occurs, and therefore there is no movement of fluid except through small passages, when one system fails,
The minimum amount of brake fluid required to operate the brakes of other systems is secured in the fluid chambers of other systems, and will not be lost due to splashing.

(5) Since the liquid chambers are commonly communicated through small passages, the structure is simple and manufacturing is easy.

That is, in the present invention, in particular, the small passage is provided by connecting the enclosing wall and the dividing wall at a portion parallel to the longitudinal direction of the vehicle body, and connecting the three rooms at this connection point. , as a passage connecting the inside and outside of the surrounding wall, perpendicular to the longitudinal direction of the vehicle body, in other words, perpendicular to the direction in which inertial force acts, and when liquid moves, combined with the throttling effect, the liquid moves. Further, since communication between the inside and outside of the enclosing wall is possible only through such small passages, this effect is further enhanced.

[Brief explanation of drawings]

Figure 1 is a front cross-sectional view of the assembled mask cylinder reservoir, cylinder body, and liquid level switch, Figure 2 is a ■-■ cross-sectional view of the reservoir in Figure 1, and Figure 3 is the same <m-m cross-sectional view. It is. 2; cylinder body, 4; cylinder hole, 6, 8; supply port,
10, 12; return port, 14, 16; discharge port, 18; reservoir, 25; outer wall, 26, 28; dividing wall, 30; surrounding wall, 32, 34, 36; liquid chamber, 38; liquid level switch, 48
, 50, 52, 54; Warimizo.

Claims (1)

[Scope of utility model registration request] The internal cavity formed by the outer wall is divided into a liquid chamber separated by a cylindrical surrounding wall and two liquid chambers separated by a dividing wall formed from the surrounding wall to the outer wall. In the reservoir of the mask cylinder, the chamber is provided with a liquid level alarm switch that is activated to give an alarm when the liquid pressure drops below a certain level, and the surrounding wall and the dividing wall are formed from the bottom to the top of the outer wall. The surrounding wall and the dividing wall are connected at a portion of the wall surface of the surrounding wall parallel to the longitudinal direction of the vehicle body, and a small passage whose lower end is at the constant height is provided at the connection point. A mask cylinder reservoir that communicates three liquid chambers.