JPS6345531Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention (1) Industrial application field The present invention is an engine breather device for maintaining an average negative pressure in the crank chamber during engine operation, particularly for a crank chamber. A through hole and a valve seat surrounding the through hole are provided in the partition plate that separates the crank chamber side from the atmosphere side, and the valve seat is provided with a check valve that opens when the crank chamber side is pressurized and closes when the pressure is reduced. Concerning what is to be created in opposition to each other.

(2) Prior Art A conventional breather device will be explained with reference to FIG. 5. 6 is a partition plate that partitions the crank chamber side A and the atmosphere side B, 13 is a through hole, 8 is a valve seat, 9 is a check valve, Reference numeral 10 denotes a valve holder for holding the check valve 9, and the through hole 13 is formed so large that it approaches the inner peripheral edge of the valve seat 8.

(3) Problems to be solved by the invention The conventional device described above has a structure in which oil droplets from the crank chamber side A gather and easily form oil droplets d at the edge of the through hole 13. Since the edge and the valve seat 8 are very close to each other, when the check valve 9 is opened,
The oil droplets d are easily carried away to the atmosphere side B through the valve seat 8 by the pressurized air that is trying to pass through the through hole 13 and the valve seat 8 with force, and as a result, oil droplets are mixed in the air discharged to the outside. However, this is one of the causes of wasting lubricating oil in the engine.

This invention was made in view of these points,
It is an object of the present invention to provide the breather device, which can effectively prevent oil droplets from being carried away from the crank chamber side to the atmospheric chamber side with an extremely simple structure.

B. Structure of the invention (1) Means for solving the problem In order to achieve the above object, the present invention provides a through hole in the partition plate that partitions the crank chamber side and the atmosphere side, and a valve surrounding the through hole. In the breather device for an engine, the valve seat is provided with a check valve that opens when the crank chamber side is pressurized and closes when the pressure is reduced. The present invention is characterized in that a bulging wall protruding from the periphery toward the crank chamber side and defining a damping chamber between the bulging wall and the check valve is integrally provided, and the through hole is bored in the bottom of the bulging wall.

(2) Effect According to the above configuration, it is possible to provide a sufficient distance between the valve seat of the bulkhead plate and the edge of the through hole that follows the valve seat, and also to provide a sufficient distance between the through hole and the check valve on the valve seat. By interposing a damping chamber in between, it is possible to reduce the flow velocity of pressurized air from the through hole toward the valve seat side when the check valve is opened, so that oil droplets attached to the edge of the through hole can be It is possible to very effectively prevent pressure air from being carried away to the atmosphere through the valve seat.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, a cylinder head 1 of an engine is formed with a valve train chamber 3 that accommodates a valve train 2. A head cover 4 is fastened to the upper end surface of the cylinder head 1 with bolts 5 to close the open upper surface of the valve operating chamber 3. Valve chamber 3
communicates with a crank chamber (not shown), and lubricating oil is circulated between the two chambers.

A partition plate 6 is fitted to the head cover 4, so that the inside of the head cover 4 has a first chamber A connected to the valve operating chamber 3, and an exhaust hole 7 provided in the head cover 4.
It is divided into a second chamber B which is connected to the atmosphere via a tube (see FIG. 2).

A valve seat 8 is formed on the partition plate 6 and protrudes in an annular manner toward the second chamber B, and a check valve 9 is disposed opposite to the valve seat 8. In order to hold the check valve 9, a valve holding plate 10 is welded to the partition wall plate 6 on the second chamber B side. Annular protrusion 10 regulating
a is formed.

The partition plate 6 further includes a first
A bulging wall 11 protruding toward the chamber A side is integrally provided and defines a damping chamber 12 between the bulging wall 11 and the check valve 9. A through hole 13 communicating between the first chamber A and the damping chamber 12 is bored at the bottom of the expansion wall 11.
The area of the through hole 13 is, when the check valve 9 is opened,
The area is selected to be equal to or slightly larger than the area of the annular passage formed between it and the valve seat 8.

Next, the operation of this embodiment will be explained.

During operation of the engine, when the crank chamber is pressurized with the downward stroke of a piston (not shown), air in the valve train chamber 3 communicating with the crank chamber flows from the first chamber A through the through hole 13 to the damping chamber. 12, push open the check valve 9, pass through the valve seat 8, and open the second chamber B.
It is discharged into the atmosphere through the exhaust hole 7.

By the way, pressurized air flows from the first chamber A to the through hole 13.
When the air passes through the valve chamber 3 and moves to the damping chamber 12, it is attenuated and the flow velocity decreases.
2, it loses its force and falls without reaching the valve seat 8 and returns to the first chamber A through the through hole 13. Also, through hole 1
3 has a sufficient distance from the opening edge to the valve seat 8, so oil droplets attached to the edge of the through hole 13 may be damaged by the pressure air whose flow velocity is lowered in the damping chamber 12. It is also rare for it to be taken away to the seat 8 and, by extension, to the second chamber B side. In this way, oil is prevented from passing through the valve seat 8.

Next, when the pressure inside the crank chamber is reduced due to the upward stroke of the piston, the pressure inside the valve train chamber 3 is also reduced.
The check valve 9 receives negative pressure from the damping chamber 12 and closes, thereby preventing air from flowing backward from the second chamber B to the first chamber A. By opening and closing the check valve 9 in this manner, the internal pressures of the crank chamber and the valve operating chamber 3 are maintained at an average negative pressure, and leakage of lubricating oil from these chambers is prevented.

It will be understood that in the above embodiment, the first chamber A corresponds to the crank chamber side in the present invention, and the second chamber B corresponds to the atmosphere side.

C. Effect of the invention As described above, according to the invention, a through hole is provided in the partition plate that partitions the crank chamber side and the atmosphere side, and a valve seat surrounding the through hole is provided, and the valve seat is provided with a valve seat that surrounds the through hole. In an engine breather device comprising a check valve that opens when the chamber side is pressurized and closes when the pressure is reduced, the partition plate has a check valve that protrudes from the inner peripheral edge of the valve seat toward the crank chamber side and connects with the check valve. Since the expansion wall defining the damping chamber is integrally installed in between, and the through hole is bored at the bottom of the expansion wall, the partition plate and the valve seat,
It is possible to provide a sufficient distance between the valve seat and the edge of the through hole following the valve seat, and a damping chamber is interposed between the through hole and the check valve on the valve seat. The flow velocity of the pressurized air toward the seat side can be reduced, which is extremely effective in preventing oil droplets attached to the edge of the hole from being carried away by the pressure air to the atmosphere side through the valve seat when the check valve is opened. Furthermore, the structure for preventing oil droplets from being taken away is extremely simple, simply having the swelling wall integrally protruded from a bulkhead plate with a valve seat. This can greatly contribute to cost reduction and improved assembly efficiency.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the present invention, in which Figure 1 is a vertical sectional side view of the main parts of an engine equipped with the device of the present invention, and Figure 2 is a sectional view taken along the line -- in Figure 3. , 3 and 4 are views taken in the direction of the arrows in FIG. 1, and FIG. 5 is a sectional view showing the conventional device. A...First chamber facing the crank chamber, B...Second chamber facing the atmosphere, 1...Cylinder head, 3...
Valve chamber, 4... Head cover, 6... Bulkhead plate, 8
... Valve seat, 9 ... Check valve, 11 ... Bulging wall, 1
2...attenuation chamber, 13...through hole.

Claims (1)

[Scope of utility model registration request] A through hole 13 in the partition plate 6 that partitions the crank chamber side and the atmosphere side is provided, and a valve seat 8 surrounding the through hole 13 is provided, and the valve seat 8 opens when the crank chamber side is pressurized to reduce the pressure. In this engine breather device, a damping chamber 12 is provided in the partition wall plate 6 and protrudes from the inner peripheral edge of the valve seat 8 toward the crank chamber side, and is disposed between the check valve 9 and the check valve 9.
The swelling walls 11 that define the
1. A breather device for an engine, characterized in that the through hole 13 is bored in the bottom of the engine.