JPS6242095Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air bleed structure for an engine used for construction machinery such as a power shovel.

In general, the air bleed mechanism that connects the inlet manifold connected to the cylinder head of the engine and the inside of the crankcase compensates for the engine's air/fuel efficiency characteristics, and also generates a mist of oil heated in the oil pan. It has the function of guiding fuel into the engine and making it into fuel.

By the way, air bleed in engines used for conventional construction machinery has been considered with reference to general vehicles, especially passenger cars.

However, construction machinery such as power shovels can be used not only on flat surfaces but also on inclined surfaces (the maximum angle of inclination is 30°).
(about 35 degrees), so if you use the air bleed mechanism of a general vehicle or work with a power shovel on a steep slope, the oil accumulated in the engine oil pan may leak out. It flows into the air bleed pipe.
As a result, the air bleed pipe was closed, making breathing difficult, and the increased pressure within the crankcase caused the oil that had flowed into the bleed pipe to spout out, worsening the combustion efficiency of the engine.

Another method for communicating the air bleed pipe is to raise it up from the crankcase surrounding the cylinder block and cylinder head and connect it to the air bleed body above the cylinder head, as described in Japanese Utility Model Application Publication No. 49-24830. If you do this,
The above problem can be solved. However, raising the passage so as to surround the engine body in this way complicates the engine structure and requires major design changes, making it impractical. There is no solution to prevent clogging of practical pipes connected with oil due to oil.

The pipe connecting the air cleaner and the crankcase shown in the above-mentioned publication is a pipe that, as pointed out above, becomes clogged with oil when the engine is tilted significantly. However, the problem of pipe clogging due to oil has not been resolved.

In yet another prior art air bleed structure, a pipe is provided to guide blow-by gas from the engine crank chamber to an oil bleeder filled with a filter, and oil separated from the blow-by gas is provided in the blow-by gas pipe. There is an idea in Japanese Utility Model Publication No. 1983-4802 in which the oil is returned to the oil pan through a return pipe.

This prior art was made to improve the conventional type in which oil separated by an air bleeder is made to flow down the blow-by gas pipe and collected in an oil pan. That is, in this prior art, when the recovered oil flows down inside the blow-by gas pipe, it is blown back by the blow-by gas that continuously rises at high speed and is returned to the air bleeder again, which improves the oil separation efficiency. However, it does not solve the problem of the above-mentioned power shovel where the engine tilts significantly and the oil in the oil pan flows into the blow-by gas pipe, closing the gas passage. It won't happen.

This invention was devised by focusing on such conventional problems, and its purpose is to easily perform air breathing even when construction machinery is used on a slope, and at the same time to prevent oil from gushing out. This provides an engine air bleed structure that effectively prevents air bleed.

In order to achieve the above objectives, the engine air bleed structure of this invention is provided with a sub-pipe within the main air bleed pipe that connects the air bleed main body located at a high position in the engine and the crankcase. The crankcase side end of the sub-pipe has a shape that protrudes toward the top, and protrudes from the end where the main pipe opens into the case, and is disposed above the opening, and the other end is The main pipe is characterized in that it opens at a high part within the upright part.

The subpipe of the present invention has the following functions. In other words, even if the engine is tilted to the side of the air bleed pipe and lubricating oil flows into the pipe, since the end protrudes from above, it will not flow into the subpipe, and the other end is opened in the rising part of the air bleed pipe, so that the lubricating oil that has flowed into the air bleed pipe is prevented from blocking the outlet of the sub-pipe within the pipe.
Since the tip of the sub-pipe is shaped to protrude toward the top, even when the engine is tilted, there is no risk of lubricating oil falling from above entering the sub-pipe, and a passage for air breathing is always secured.

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

1 is an engine used for construction machinery, and between an inlet manifold 5 attached to a cylinder head 3 of this engine 1 and a crankcase 7, there is an air tank equipped with an oil separator (not shown). An air bleed mechanism 13 consisting of a bleed body 9 and an air bleed pipe 11 is interposed. The air bleed body 9 is connected to the inlet manifold 5, and the lower surface of the air bleed body 9 has a substantially L-shaped cross section that is connected to the side wall of the crankcase 7 through a sealing material 15 and a cover 17. The air bleed pipe 11 is provided. A sub-bleed pipe 19 having a substantially L-shaped cross section and cut at an inclined end is fixed to the upper inner wall surface 11a of the air bleed pipe 11 by welding or the like.

One end of the sub-bleed pipe 19 protrudes into a cover 17 attached to the side wall of the crankcase 7, and the other end opens above the air bleed pipe 11 that stands parallel to the engine 1. Note that 21 is a cylinder head cover attached to the upper part of the cylinder head 3, and 23 is an oil pan attached to the lower part of the crankcase 7.

That is, even if the engine 1 of this embodiment is tilted and the oil Q in the oil pan 23 flows into the air bleed pipe 11, the air bleed main body 9 and the crankcase 7 are separated by the sub-bleed pipe 19. You can maintain communication with
Gas and oil pan 23 in crankcase 7
The misted oil inside can be guided into the cylinder head 3 of the engine 1.

As explained above, the air bleed structure of the present invention is such that a sub-pipe is provided within the main air bleed pipe that connects the air bleed main body located high in the engine and the crankcase, and the sub-pipe is provided on the crankcase side. The end part has a shape that protrudes toward the top, and the end part protrudes from the end part where the main pipe opens into the case, and is disposed above the opening part, and the other end part is located above the opening part of the main pipe. Because the opening is made at a high point within the raised section, even if the engine is tilted and the oil in the oil pan flows into the air bleed pipe, the air bleed pipe remains in communication at all times. This does not impair air breathing, and it also prevents pressure from rising inside the crankcase, which has the effect of preventing oil that has flowed into the pipe from spouting out.

Therefore, for example, when the engine is mounted on a mechanical device such as a power shovel that requires work on a large slope with an angle of 30° to 35° depending on the work situation, it is necessary to It can be effectively applied as an air bleed structure for engines that may be used.

[Brief explanation of the drawing]

The drawing is a sectional view of the air bleed of the engine according to this invention. 1...Engine, 3...Cylinder head, 7...
...Crankcase, 11...Air bleed pipe, 19...Sub bleed pipe.

Claims (1)

[Scope of utility model registration request] A sub-pipe is provided within the main air bleed pipe that connects the air bleed main body located at a high position of the engine and the crankcase, and the crankcase side end of the sub-pipe has a shape that protrudes toward the top. and that the main pipe protrudes from an end opening into the case and is located above the opening, and the other end is opened at a high part within the rising part of the main pipe. The engine features an air bleed structure.