JP2503109Y2 - Breather device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a breather device for a side valve type engine.

[Conventional technology]

A conventional breather device for a 4-cycle valve type general-purpose engine will be described with reference to FIGS.
2 is a gasket, 3 is a cylinder, 4 is a crankcase,
5 is a crank chamber, 6 is a piston, 7 is a connecting rod, 8 is an intake valve, 9 is an intake passage, 10 is a carburetor, 11 is a tappet chamber, 12 is a tappet, 13 is an intake cam, and 20 is a breather device. The breather device 20 includes an outer plate 21 and a small hole 22 formed in the outer plate.
A check valve 23 and a support plate 24 made of an elastic material mounted on the inner surface of the outer plate 21 by rivets or the like so as to face the small hole, an air chamber 25 in the outer plate 21, and the outer plate 21. A small hole 26 formed in the lower part of the pipe, a cover 27 of the tappet 12, a pipe 28 opened to the air chamber 25, a hose 29 for connecting an air cleaner (not shown) to the pipe 28, and a packing 31.
It is composed of A communication hole 30 that communicates the crank chamber 5 and the tappet chamber 11 is provided in the lower portion of the tappet chamber 11, and the spring 14 of the intake / exhaust valve is provided in the tappet chamber 11.
The spring bridge 15 is stored.

 Next, the operation of the conventional example will be described.

While the engine is rotating, blow-by gas containing oil is discharged from the crank chamber 5 through the communication hole 30 and the tappet chamber 11 to an air cleaner (not shown) due to pressure fluctuations in the crank chamber 5. In order to prevent this, after the oil and the gas are separated by the breather device, only the gas is sent to the air cleaner, while the oil is returned to the tappet chamber 11. That is, when the internal pressure of the crank chamber 5 is a positive pressure, the blow-by gas containing oil flows through the crank chamber 5 → the communication hole 30 → the tappet chamber 11 → the small hole 22 of the outer plate 21 to the air chamber.
When it enters 25, it collides with the check valve 23 to separate the oil and gas, and only this gas is sent from the pipe 28 to the air cleaner through the hose 29, while the oil separated from the gas is provided in the lower part of the outer plate 21. The small holes 26 are dropped into the tappet chamber 11 and returned to the crank chamber 5 when the internal pressure of the crank chamber 5 is a negative pressure.

[Problems to be solved by the device]

However, when the general-purpose valve engine tilts and the amount of lubricating oil splashes in the crankcase 4 increases, the lubricating oil is sucked into the engine from the air cleaner while containing a large amount of lubricating oil in the gas. Generation of white smoke due to combustion of
Problems such as smoldering of the spark plug, clogging of the air cleaner element, malfunction of the engine, increase of lubricating oil consumption, etc. will occur.

An object of the present invention is to solve the problems of the conventional device and to provide a breather device in which the lubricating oil is not discharged together with the breather gas even when the engine is tilted.

[Means for solving the problem]

The breather device of the present invention has a check valve chamber and a check valve cover in a tappet chamber which also serves as a valve chamber of a side valve type engine and communicates with a crankcase through a ventilation hole. An oil barrier member is erected between the tappet chamber and the space where the vent is opened and the space communicated with the check valve opening, and there is a gap between the lower end of the oil barrier member and the bottom surface of the tappet chamber. It is characterized in that it is partitioned by the presence of γ, and that a vent hole cover is laterally provided so as to cover the upper part of the vent hole.

[Action]

When the general-purpose engine tilts and the crankcase chamber has a positive pressure, even if the breather gas containing a large amount of lubricating oil flows into the tappet chamber 11 through the communication hole 30 that communicates between the crankcase chamber and the tappet chamber 11, Lubricating oil is blocked by the vent hole cover 60, the oil shield member 52, etc., and does not flow out to the air cleaner through the check valve.

〔Example〕

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

FIG. 1 is a vertical sectional view of the breather device according to the first embodiment, and FIG. 2 is a sectional view taken along line II-II of FIG.

A check valve cover 51 is fixed to the outer plate 21 of the breather device 20, and has a check valve opening 51a on the intake valve 8 side. An oil shield 52 extends from the check valve cover 51 toward the cylinder 3. As shown in FIG. 2, the tappet chamber 11 is partitioned by the oil shield plate 52 into a space 11a in which the vent hole 30 is opened and a space 11b in communication with the check valve opening 51a. , 11b are communicated with each other through gaps (narrow overflow portions) α, β, γ between the end face of the oil shield plate 52 and the side face, top face, and bottom face of the tappet chamber. Reference numeral 60 denotes a ventilation hole cover which is provided horizontally on the breather device 20 and covers the ventilation hole 30.

 Next, the operation of the first embodiment will be described.

Even if the breather gas containing the lubricating oil is ejected from the vent hole 30, most of the lubricating oil is returned by the vent hole cover 60 covering the upper part of the vent hole 30. In addition, a part of the lubricating oil that has passed through the ventilation hole 30 is also blocked by the oil shield plate 52, which stands upright in the cylinder direction from the check valve cover 51, to the back of the tappet chamber 11, so that the lubricating oil is dammed and checked. Valve opening
It does not flow in the direction of 51a. A part of the lubricating oil that has passed through the ventilation holes 30 is blocked by the oil shield plate 52, passes through the wall surface, the ceiling, and the floor and is returned from the ventilation holes 30 to the crank chamber 4. On the other hand, the gas flows from the clearance α between the oil shield plate 52 and the outer circumference of the cylinder and the upper and lower narrow overflow parts β and γ of the tappet chamber 11 to the opening 51a of the check valve 51.
And is discharged from the check valve cover 51 through the check valve 23 to the outlet hole 28.

Note that the mist-like lubricating oil contained in the gas component is gas-oil separated in the check valve chamber 25, and is returned to the crank chamber through the vent hole 30 from a small hole 26 for oil return provided in the bottom of the check valve chamber. .

FIGS. 3 to 4 show the same results as the present invention.
This is an embodiment, and the second embodiment of FIG. 3 shows an oil shield rib 53 projecting from the outer peripheral portion of the cylinder toward the check valve cover 51. The oil shield plate 52a and the oil shield rib 53 are provided so as to overlap with each other with a gap δ as shown in the drawing.

The third embodiment shown in FIG. 4 shows an embodiment in which the oil shield rib 53a is extended to the vicinity of the check valve cover 51.

The other members of the second to third embodiments are the same as those of the first embodiment.

[Effect of device]

According to the present invention, when the engine tilts and the amount of lubricating oil scattered in the crank chamber increases, the lubricating oil in the blow-by gas ejected from the vent hole 30 is returned to the crank chamber by the vent hole cover 60 and passes through the vent cover. Some of the lubricating oil that has been used is dammed up by an oil blocking member that is erected between the check valve cover 51 and the cylinder 3, and is prevented from being discharged from the check valve 23 to the outlet hole 28. It is possible to prevent malfunctions such as smoldering of the plug and clogging of the air cleaner element, and problems such as an increase in lubricating oil consumption.

[Brief description of drawings]

1 to 4 relate to the present invention. FIG. 1 is a longitudinal sectional view of a main part of the first embodiment, FIG. 2 is a II-II sectional view of FIG. 1, and FIG.
FIG. 2 is a second drawing of the second embodiment, FIG. 4 is a second drawing of the third embodiment, FIGS. 5 to 6 are conventional examples, and FIG. 5 is a longitudinal sectional view around a combustion chamber. FIG. 6 is a view on arrow VI of FIG. 3 ... Cylinder, 5 ... Crank chamber, 11 ... Tappet chamber, 25 ... Check valve chamber, 30 ... Vent hole, 51 ... Check valve cover, 51a ... Check valve opening, 52, 52a, 53 , 53a
…… Oil shield, 60 …… Vent hole cover.

Claims (2)

(57) [Scope of utility model registration request] 1. A ventilation hole (3
Tappet chamber (11) connected to the crank window via (0)
A breather device having a check valve chamber (25) and a check valve cover (51) inside, wherein a check valve cover (51) in the tappet chamber and a cylinder (3) are provided from the outer surface of the check valve cover to the cylinder. The oil shield member (52) extending toward the bottom of the tappet chamber (11) with a gap (γ) between the lower end and the bottom surface of the tappet chamber (11). A breather device, which is partitioned into a space communicating with a space check valve opening (51a) in which the vent hole (30) opens. 2. The vent hole cover (60) is further provided on the upper part of the vent hole (30) so as to cover the vent hole.
The breather device described.