JPH053691Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a breather mechanism for a general-purpose vertical engine.

[Conventional technology]

FIG. 9 shows a longitudinal sectional front view of a breather mechanism in a splash type lubrication system for a vertical engine.
In the figure, 1 is the crankcase, 2 is the cover, and 3
is the check valve, 4 is the crankshaft, 5 is the breather outlet, 6 is the hole drilled in the crankcase 1,
7 is a space constituted by case 1 and cover 2;
8 is a space that communicates the check valve 3 and the breather outlet 5. The hole 6 communicates the inside of the crankcase 1 with the space 7, and the space 8 is connected to the space 7 via the check valve 3. 9 is a journal bearing that supports the crankshaft 4 in the case 1.

When the engine is operated, the internal pressure in the crankcase becomes positive when the piston descends, and this pressure
The outside air is released through the following path: → space 7 → check valve 3 → space 8 → breather 5. At this time, the air is mixed with atomized oil, and this oil reaches the journal bearing 9 from the space 7. As a result, oil adheres to the journal bearing 9 and provides lubrication. Although the breather mechanism is used to lubricate the journal bearing in this way, the number of parts and the number of machined parts increase (the journal bearing fitting hole 9 of the crankcase 1,
In addition to hole 6, parts marked with * are machined parts such as the contact parts with cover 2). Note that 10 indicates an oil seal.

[Problems to be Solved by the Invention] However, as described above, the conventional example has the disadvantage that the breather mechanism has a large number of parts and many parts require pressure machining.

The purpose of the present invention is to eliminate the drawbacks of the conventional example,
It is an object of the present invention to provide a breather and a lubrication mechanism which have the same functions as the conventional example and have the number of parts and machined parts minimized.

[Means to solve the problem]

The breather mechanism of the vertical internal combustion engine of the present invention has a communication hole 16 formed by casting so as to communicate the space formed above the upper bearing of the crankshaft with the inside of the crank chamber. ,
A breather chamber 17 which communicates with the communication hole through a drilled hole 19 and is formed by casting with a part open, and a check valve which is removably attached to the open part of the breather chamber are integrated. The breather chamber lid 22 is provided with a breather chamber lid 22, and the breather chamber is divided into two chambers by the breather chamber lid.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a longitudinal sectional view corresponding to FIG. 9 of the conventional example,
2 is a view taken in the direction of the arrow in FIG. 1, FIG. 3 is a partially sectional front view of the breather chamber lid, and FIG. 4 is a side view of the breather chamber lid.

In the figure, a crankcase 11 rotatably supports a crankshaft 12 via a bearing 13 and an oil seal 14. 15 is a boss and the bearing 13
The bearing 13 has a cast hole 16 on its outer periphery. 18 is a space formed in the upper part of the bearing 13 and serves as a blow-by gas passage; 19 is a cast hole that communicates the space with the breather chamber 17; Reference numeral 20 denotes a breather pipe connection boss, which projects from the breather chamber 17 and has a cast hole 21 that communicates the breather chamber 17 with the outside.

22 is a breather chamber cover, which is made of synthetic resin and has a T-shaped cross section, a check valve 24, and a support plate 25.
and a rivet 26. Reference numeral 23 denotes a main body whose side edges 27 and lower edge 28 in FIG.
The side edge 27 has a saw-shaped tooth 31 that is smooth during insertion and provides resistance when removed after installation. The breather chamber lid 22 divides the breather chamber 17 into a front chamber 17a and a rear chamber 17b.

Further, the portion facing the check valve 24 has a plurality of small holes 32. 33 and 34 are breather room 1
The separated oil is returned to the case 11 through a return hole formed in the bottom wall of the case 7.

The parts of the crankcase 11 other than those marked with * remain as cast surfaces.

Next, the operation of the above embodiment will be explained.

The positive pressure inside the crankcase 11 generated when the piston (not shown) descends from the cast hole 16 to the space 18
Air flows through the following route: → cast hole 19 → front chamber 17a → small hole 32 → check valve 24 → rear chamber 17b → cast hole 21, and is released to the outside air. When the pressure inside the crankcase 11 is negative, the check valve 24 closes the small hole 32 and the front chamber 17a and rear chamber 17b are separated. The air containing the atomized oil thus reaches the bearing while passing through the above-mentioned path and performs a lubricating action.

In this way, the pressure inside the crankcase and the bearing lubrication can be simultaneously performed.

Figure 5 shows the second embodiment, and is a cutaway plan view of a portion corresponding to Figure 2 of the first embodiment, Figure 6 is a cross-sectional view of Figure 5, and Figure 7 is a cross-sectional view of the breather chamber cover. 6
8 is a view in the direction of the arrows in FIG. 7.

Next, differences from the first embodiment will be explained.

35 is a breather chamber, and in addition to the vertical groove 36 and the bottom groove 37, partial vertical grooves 38 and partitions 39 are formed by casting. The front chamber 3 is closed by a breather chamber cover 40 to be described later.
5a and a rear chamber 35b. 40 is a breather chamber lid, and the main body 41 is made of synthetic resin and has a T-shaped cross section.
and a partition 42 inserted into the partial vertical groove 38,
It is composed of a check valve 24, a support plate 25, and a rivet 26.

As in the first embodiment, the air containing atomized oil flows through the cast hole 16 → space 18 → cast hole 19 → front chamber 35a → small hole 32 → check valve 24 → rear chamber 3
5b→gap 43→cast hole 21, and is released to the outside air. In the second embodiment, the breather chamber 35
By forming a labyrinth with the partitions 39, 42, etc., it becomes easier to separate oil from the air passing through.

[Effects of the invention] As mentioned above, the breather mechanism for an internal combustion engine according to the present invention is a vertical engine splash type lubrication system, in which a breather chamber with an open upper part is cast at the top of the crankshaft, and this breather chamber is opened at the top by casting. The chamber is removably fitted with a breather chamber lid that integrates a check valve and breather lid that only allows air to flow from the crank chamber in the direction of outside air, which simplifies the structure compared to conventional ones and reduces the number of parts. In addition, by providing many cast holes, the number of machined parts can be reduced, and production costs can be lowered.

[Brief explanation of the drawing]

Figures 1 to 4 are a first embodiment of the present invention; Figure 1 is a vertical sectional view of the main part; Figure 2 is a view taken in the direction of the arrows in Figure 1; Figure 3 is a partial sectional view of the breather chamber cover; Figure 4 is the third
5 to 8 are the second embodiment of the present invention, FIG. 5 is a cutaway plan view of a portion corresponding to FIG. 2 of the first embodiment, and FIG. 6 is the − of FIG. 5. 7 is a sectional view of only the breather chamber cover in FIG. 6, FIG. 8 is a view of FIG. 7 in the direction of arrows, and FIG. 9 is a longitudinal sectional front view of the conventional example. 12...Crankshaft, 13...Upper bearing part, 1
7, 35...breather chamber, 24...check valve,
22,40...breather chamber lid.

Claims (1)

[Claims for Utility Model Registration] In a vertical internal combustion engine equipped with a splash-type lubrication device and a blow-by gas passage leading to the outside of the crankcase through a space formed above the upper bearing of the crankshaft, A communication hole 16 that is formed by casting out of the crankcase adjacent to the upper bearing and communicates between the inside of the crankcase and the space, and a communication hole 16 that communicates with the space 18 through the casting hole 19 and is partially open. It has a breather chamber 17 formed by casting, and a breather chamber lid 22 that is removably attached to the opening part of the breather chamber 17 and is integrally equipped with a check valve. A breather mechanism for an internal combustion engine, characterized in that a chamber is divided into two chambers via a check valve.