JPS5943160Y2 - Reservoir cap in master cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reservoir cap in a master cylinder.

The cap of the reservoir in the master cylinder is provided with a vent hole for constantly communicating the inside of the reservoir with the atmosphere.

This vent hole is designed in various ways to prevent oil from leaking from the reservoir to the outside through the vent hole due to vibration.

The most common example is a cap with a plurality of hollow chambers through which atmospheric air is introduced into the reservoir.

However, none of the conventional devices having such a configuration has been able to achieve reliable leakage prevention.

An object of the present invention is to solve these problems by providing a cap with a simple structure.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a longitudinal cross-sectional view of a part of the reservoir body and the entire cap of the master cylinder according to the present invention.

The cap 1 according to the present invention includes an outer cap 2, an inner cap 3, and a plate 4.

The outer cap 2 has a small diameter cylindrical body 5 on its central lower surface.
is installed protrudingly.

The inner cap 3 has a large-diameter cylindrical body 6 protruding from its upper central surface, and a ventilation hole 7 protruding from its bottom.

The plate 4 has a ventilation hole 8 projecting from the upper and lower surfaces of the center thereof, and leg portions 9 projecting from the lower peripheral surface.

These outer cap 2 and inner cap 3 are fitted together so that the cylindrical bodies 5 and 6 face each other, and are positioned below the lower end of the small diameter cylindrical body 5 of the outer cap 2, and A plate 4 is slidably disposed inside a large-diameter cylindrical body 6 and is assembled into a cap 1.
and the cap is fitted onto the reservoir body 10.

As a result, in the cap 1, there is a recess 11 as an oil reservoir formed inside the small diameter cylindrical body 5 of the outer cap 2, and a concave part 11 as an oil reservoir formed inside the small diameter cylindrical body 5 of the outer cap 2 and a large diameter cylindrical part of the inner cap 3. An annular space 12 formed between the body 6 and the body 6
A large hollow chamber A consisting of the above, and a first hollow chamber 13 consisting of the lower surface of the plate 4 and the large diameter cylindrical body 6 of the inner cap 3 are formed.

Note that the hollow chamber in the present invention refers to a chamber that is completely surrounded by a wall, and the hollow chambers are communicated with each other through ventilation holes protruding from the iron wall.

Therefore, as shown by the arrow in Figure 1, the atmosphere
A gap 14 formed by the inner surface of the circumferential wall of the cap 20 and the outer surface of the circumferential wall of the reservoir body 100, a ventilation hole 15 formed by the lower surface of the outer cap 2 and the upper circumferential surface of the inner cap 3, and the outer circumferential side of the cylindrical body 6 of the inner cap 3. an annular chamber 16 formed between the outer cap 2 and the upper end surface of the inner cap 30 and the inner cap 30;
An annular space 12 formed by the cap 20 and the cylindrical body 5, a gap 18 between the lower end of the outer cap 20 and the cylindrical body 5 and the upper surface of the plate 4, a ventilation hole 8 in the plate 4, and a lower surface of the plate 4 and the inner cap. 3 and the first hollow chamber 13 formed by the upper surface of the inner cap 30 and the ventilation hole 7
It is guided into the reservoir main body 10 through the.

Note that 19 in FIG. 1 is a filter.

Figure 2 (■) is an enlarged view of the main part of Figure 1, and shows the stable state of the reservoir 1, that is, the normal state in which the reservoir cap 1 is not vibrating enough to cause the plate 4 to move up and down. be.

If large vibrations occur in the cap 1 in this state,
The plate 4 jumps up as shown in FIG. An isolation chamber 20 is formed there.

During this time, the ventilation hole 7 of the inner cap 3 and the plate 40
The oil leaked out of the reservoir body 10 through the vent hole 8,
Accumulates in isolation room 20.

However, since the outer peripheral gap of the plate 4 is formed to be very narrow, a throttling effect acts on the oil passing through this gap.
The ejection resistance increases.

As a result, only a very small amount of oil flows into the annular space 12.

Subsequently, when the plate 4 returns to the state shown in FIG.
is formed, so that the oil accumulated in the isolation chamber 20 and the annular space 12 flows through the ventilation holes 8. of the plate 4. The water flows back into the reservoir main body 10 through the inner cap 30 vent hole 7.

At this time, since the oil liquid flowing back is not subjected to the throttling effect due to the outer peripheral gap of the plate 4, its flow resistance is small, and the oil liquid smoothly flows back into the reservoir body 10.

If the vibrations generated in the reservoir are continuous, the above action will be repeated.

During this time, the plate 4 moves up and down almost in synchronization with the discharge movement of the oil from the reservoir body 10, thereby creating an annular space formed by the cylindrical body 5 of the outer cap 20 and the cylindrical body 6 of the inner cap 3. 12 to prevent the oil from flowing out to the outside as much as possible.

In the above embodiment of the present invention, the plate 4 is installed in the inner cap 30 and the cylindrical body 6 so as to be movable up and down, and when the plate 4 is at the uppermost position, the plate and the cylindrical body of the outer cap 2 This forms an isolation chamber, thereby temporarily insulating the inside of the reservoir body 10 from the atmosphere.

Therefore, since the plate 4 is disposed on the cylindrical body 6 of the inner cap 3 so as to be movable up and down, a slight gap is formed between the sliding surfaces of the plate 4 and the cylindrical body 6.

This gap is, of course, necessary for the plate 4 to move up and down smoothly, but also has the following important functions.

In other words, if the pressure inside the reservoir increases due to a rise in the oil level or a change in outside temperature, this pressure will be formed around the plate 4 even if it moves upward as shown in Figure 2 (■). It is smoothly discharged to the outside through the gap.

Therefore, no unexpected pressure is applied to the oil level in the reservoir, and erroneous operation of the brake system is reliably prevented.

Note that the amount of oil flowing out through this gap into the annular space 12 formed by the cylindrical body 5 of the outer cap 2 and the cylindrical body 6 of the inner cap 3 is so small that it can be ignored.

In addition, if there is a risk that the lower end of the cylindrical body 5 of the outer cap 2 and the upper surface of the plate 4 may stick together due to the adhesive force of oil, the lower end surface of the cylindrical body 5 of the outer cap 20 should be roughened. As described above, in the reservoir cap of the master cylinder according to the present invention, the plate jumps up almost in synchronization with the oil discharged from the reservoir body due to vibration, and the plate prevents the attachment of the oil to the atmosphere. Since there is no possibility of the oil discharged from the reservoir body leaking to the outside during that time, it is possible to completely prevent the oil from leaking out of the reservoir.

Moreover, since the plate is arranged to be movable up and down with a predetermined gap formed between it and the inner circumferential wall of the large diameter cylindrical body, the inside of the reservoir body and the atmosphere are always communicated through the gap. Therefore, no unexpected pressure is applied to the oil level in the reservoir, and malfunction of the brake system is reliably prevented.

Further, a plate is disposed below the oil reservoir chamber so that the oil reservoir chamber can be closed off by this plate, so that the weight of the oil stored in the oil reservoir chamber acts directly on the plate.

Therefore, the plate that has moved upward quickly and reliably returns to its original position due to its own weight and the weight of the oil, and the oil in the oil reservoir is smoothly returned to the reservoir body.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of part of the reservoir body and its entire cap in the master cylinder according to the present invention, and Figure 2 (■) is an enlarged cross-sectional view of the main part, showing the state in which the plate is in its normal position. The figure shown in FIG. 2 (2) is an enlarged cross-sectional view of the main part showing the state where the plate is in the flipped up position. 1... Cap, 2... Outer cap 3... Inner cap, 4...
Plate, 5゜6... Cylindrical body, 8...
Ventilation hole, 10... Reservoir body, 11...
・・Concave part (oil reservoir chamber), 12 annular space part, 17...
- Ventilation holes, 20 isolation rooms.

Claims (1)

[Claims for Utility Model Registration] The upper end opening of the reservoir of the master cylinder is covered twice with an inner cap and an outer cap each having a ventilation hole, and a plurality of hollow chambers communicating with each other are formed between the two caps. forming one of the hollow chambers in communication with the interior of the reservoir through a vent hole in the inner cap, and communicating the other hollow chamber with the outside of the reservoir through a vent hole in the outer cap. In the reservoir cap of the master cylinder, which communicates with the reservoir so that air in the reservoir can enter and exit through the vents of both caps and a plurality of hollow chambers, a) protruding from the upper surface of the inner cap 3; a large-diameter cylindrical body 6 surrounding the ventilation hole 7; b) a small-diameter cylindrical body 5 that protrudes from the lower surface of the outer cap 2 and loosely fits into the inner periphery of the large-diameter cylindrical body 6; ) Ventilation hole 17 formed at the upper end of the large diameter cylindrical body 6
and d) A predetermined gap is formed between the lower end of the small-diameter cylindrical body 5 and the upper surface of the inner cap 3 and the inner circumferential wall of the large-diameter cylindrical body 6 to enable vertical movement. e) a ventilation hole 8 formed in the plate 4 and opening facing the inside of the small diameter cylindrical body 5; and f) the large diameter cylindrical body 6 and the small diameter cylindrical body 5. and an annular space 12 formed between the plate 4 and the inner cap 30, and the annular space 12 is communicated with the inside of the reservoir via the outer circumferential gap of the plate 4 and the vent hole 1 of the inner cap 30, and the plate 4 A cap for a reservoir in a master cylinder, characterized in that when it comes into contact with the lower end of the small diameter cylindrical body 5, an isolation chamber 20 is formed inside the small diameter cylindrical body 5.