JPS585165Y2 - air breather - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of an air breather attached to a transmission case, a rear differential case, etc.

The air breather described above is installed at the top of a case such as a rear differential case, and discharges the expanding gas inside the case to the outside. A function is required to prevent the leakage to the outside as much as possible.

As such an air breather, for example, the one described in Japanese Utility Model Publication No. 52-36938 shown in FIG. A plurality of shielding plates 15 are fixed downwardly on the inner circumferential surface of the cylindrical part 110, and the distal ends of the shielding plates 15 overlap each other and face each other in different steps. A groove 16 is provided, and a cap 13 is placed over the head to form an air passage 14 communicating with the air passage 14. According to this, since the inner surface of the cap 13 is formed flat, there is no shielding. If the oil rises inside the cylindrical portion beyond the plate 15, it is not possible to sufficiently prevent the oil from flowing out.

In other words, when such an air breather is installed in the differential case 8 of an automobile, a large amount of oil may be splashed on the air breather mounting part due to high-speed movement of the vehicle body, or the air breather mounting part may be damaged due to uphill driving. When the level of oil in the vicinity rises, the oil blows up over the shielding plate 15, passes through the cylindrical portion 11, reaches the cap 13, and is deposited there as oil droplets.

These oil droplets easily sink due to vibrations during operation of the vehicle and flow out through the left and right air passages 14 formed between the cap 13 and the head.

Also known is the air breather described in Japanese Utility Model Publication No. 46-29062 filed by the present applicant as shown in FIG. A notch 3 is provided in the upper part of the main body 1, and a gap 6 is provided between the cap 5 and the upper surface of the flange 2 and the notch 3, and the cap 5 is loosely fitted so as to be movable up and down. The air breather is equipped with a spherical or inverted conical protrusion T, but as mentioned above, when the car is operated at high speeds, a large amount of oil can be scattered on the air breather mounting part, and when the car is running uphill, When the oil level near the air breather mounting part rises, the oil flows through the notch 3 or as the cap 5 is pushed up.
It flows out through the gap formed between this and the flange 20.

Therefore, such an air breather has a drawback in that it cannot function satisfactorily to prevent oil from flowing out.

The present invention was developed in view of the above circumstances, and aims to provide an air breather that has a simple structure but can effectively eliminate the above-mentioned defects and sufficiently prevent oil leakage. .

In order to achieve this purpose, the air breather according to the present invention has a cylindrical part with a cylindrical part inner circumferential surface so as to block the direction in which the oil is scattered inside the object to which the air breather is attached, such as a rear differential case. A partition plate is fixedly installed from the reaching side to the opposite wall surface, the top surface of which slopes downward toward the tip, and the tip of the partition plate and
An air passage is formed between the inner wall surface of the cylindrical part and the opposite inner wall surface of the cylindrical part, and a band-shaped notch is provided in the head of the cylindrical part on the opposite side of the air passage, so as to be in close contact with the upper surface of the head. A conical or pyramid-shaped protrusion is provided on the back surface of the fitted cap so that the protrusion faces into the cylindrical portion, and the lower end of the protrusion is located above the portion other than the air passage, and an air passage is formed between these. The present invention is characterized in that the oil blown up into the cylindrical portion is configured to drip toward the inside of the case body.

Embodiments of the present invention will be specifically described below with reference to the drawings.

1 and 2 show an air breather according to the present invention, and reference numeral 1 in the figures indicates a rear differential case body to which the air breather according to the present invention is attached;
2 is a cylindrical portion of the air breather.

Further, the arrows indicate the direction in which oil is scattered inside the case.

A partition plate 3 is fixed to the inner peripheral surface 2a of the cylindrical portion 2 at approximately the center in the vertical direction from the oil reaching side to the wall surface on the opposite side, the upper surface of which slopes downward toward the tip. Ori,
A semicircular air passage 4 is formed between the tip 3a and the wall surface.

Further, a protrusion 2b for locking the cap 5 is provided around the head of the cylindrical portion 20, and a notch 6 is further provided in a portion of the head of the cylindrical portion 20 opposite to the air passage 40. The cap 5 is fitted tightly onto the upper surface of the cylindrical portion 5 by the protruding portion 2b.

A conical protrusion 5a is provided on the back surface of the cap 5 so as to protrude downwardly inside the cylindrical portion 2, and its lower end apex is located above the portion other than the air passage 4, A space formed by the protrusion 5a and the partition plate 3 is communicated with the air passageway 4 and the notch 6, thereby forming an air discharge path.

In the air breather configured in this way, the oil that is normally scattered in the direction shown by the arrow in FIG. 2
Even if the oil infiltrates into the partition plate 3, it collides with the lower surface of the partition plate 3 on the fixed part side and is prevented from blowing upward.

In addition, under severe conditions such as when the oil level rises relative to the air breather installation position, such as when the car is mounted or when driving at high speed, or when a large amount of oil is splashed, the oil may Even when the air blows upward through the air passage 4 formed at the tip of the plate 3, the notch 6 that communicates with the outside is connected to the air passage 4 at the head of the cylindrical part 20.
Since the cap 5 is provided on the opposite side of the head and is in close contact with the upper surface of the other part of the head, the oil passing through the air passage 4 and scattering upward as shown by the dotted line arrow, A projection that does not flow out to the outside and whose lower end apex collides with a downward slope on the side of the passageway 4 of a conical or pyramidal projection 5a located above a portion other than the air passageway 4, and which continues on this slope. 5a, it goes around the downward slope on the opposite side of the passageway 40 along with the air (during which time, most of it becomes oil droplets and adheres to these slopes, etc., and these oil droplets also Without stopping, it easily drips from the center along the slope, and then flows downward along the slope of the upper surface of the partition plate 3 and returns to the inside of the rear differential case body 1. , oil hardly ever reaches the space facing the notch 6, and therefore almost no oil flows out from the notch 6.

Thus, according to the present invention, even under vehicle operating conditions in which a larger amount of oil than normal is splashed on the air breather mounting part, the oil that has blown up from inside the case into the air breather cylindrical part can easily be spilled inside the case. This eliminates the defects of the prior art, as the liquid is returned to the original state and prevented from leaking outside.

In addition, the structure is simple and there is no need to provide a plurality of shielding plates as in the above-mentioned known technology, so production costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view of the cylindrical portion 2 in FIG. 1, and FIGS. 3 and 4 are sectional views of a conventional air breather. 1... Rear differential case body, 2
...Air breather cylindrical part, 2a...Inner peripheral surface of the cylindrical part, 2b...Protrusion part, 3...
Partition plate, 3a...Tip, 4...Air passage, 5...Cap, 5a...Protrusion, 6... Notch.

Claims (1)

[Scope of Claim for Utility Model Registration] An air breather for a rear differential case, etc., in which a cap is fitted to the upper end of a cylindrical part with openings at both ends, and an air passage is formed between the inside of the cylindrical part and the cap. From the side wall surface where the oil splashed from inside the case reaches the inner wall of the cylindrical section, the upper surface slopes downward toward the tip, and the tip and the inner wall of the cylindrical section are connected to each other. A partition plate that forms an air passage therebetween protrudes and surrounds the cap, and the cap is brought into close contact with the upper end of the cylindrical portion, and has an inverted conical or inverted pyramid-shaped protrusion on the back surface thereof directed into the cylindrical portion, Moreover, the lower end apex is located above a portion other than the air passage, and an air passage opening is provided in a portion of the head of the cylindrical portion on the opposite side of the air passage; An air breather characterized in that it is configured to return oil blown up from the inside of a case etc. into the case. ,′