JPS62131955A - Cylinder head cover structure for engine - Google Patents

Abstract

PURPOSE:To separate oil during passing of blow-by gas, by forming ribs which extends in the direction substantially orthogonal to the cylinder arranging direction, in the inner surface of a cylinder head covers at positions shifted from valve drive mechanism in the cylinder arranging direction. CONSTITUTION:Rib members 13 are formed on the inner surface of a cylinder head cover 2, projecting downward and directed toward spaces between adjacent valve drive mechanisms 3, and are directed from one of opening side edges of the cylinder head cover 2 to the other, and overhangs orthogonal to the cylinder arranging direction. That is, they are projected downward to check blow-by gas which travels along the axial direction of a cam shaft in a rocker room 4, crossing the stream of the blow-by gas.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a cylinder rad cover structure in an engine in which blow-by gas is taken out to the outside via a locker chamber covered with a cylinder head cover.

(Prior Art) Conventionally, in this type of engine, an oil separator is installed on the cylinder head cover in order to separate and recover oil mist contained in blow-by gas, as disclosed in Japanese Utility Model Application Publication No. 56-149013, for example. has been established.

Generally, an oil separator is equipped with a maze of partition walls inside and at the inlet, and while the blow-by gas bypasses the partition walls, oil mist collides with and adheres to the partition walls and the inner wall of the separator. Efforts are being made to separate and recover the waste.

(Problems to be Solved by the Invention) Incidentally, in order to more reliably separate the blow-by gas and oil mist as described above and to reduce oil consumption, it is better to improve the ability of the oil separator. However, as mentioned above, in a device that separates oil mist by dividing the interior of the separator into a labyrinth shape with partition walls, in order to obtain sufficient oil separation performance, the size of the internal space of the separator must be made considerably large. This tends to cause new problems, such as an increase in weight and manufacturing costs, and a reduction in the freedom of design regarding its layout. Due to these circumstances, conventional oil separators have been set to be somewhat smaller in terms of capacity and structure, and a certain increase in oil consumption has been unavoidable.

(Objective of the Invention) The present invention makes it possible to separate oil mist with a simple structure that utilizes existing structures, and reduces weight and! ! The objective is to improve oil separation performance and reduce oil consumption without causing a significant increase in manufacturing costs.

(Means for Solving the Problems) In the present invention, an oil separation function is provided to the locker chamber, which serves as a passage for blow-by gas, so that oil mist can be directly separated in the locker chamber.

Specifically, the locker chamber is divided by a valve mechanism disposed in the cylinder head and a member protruding from the inner surface of the cylinder head cover so as to intersect with the flow direction of the blow-by gas, so that the blow-by gas does not reach the valve mechanism. The structure is such that it meanders up and down while bypassing the tab member. To this end, the rib member is protruded substantially orthogonally to the cylinder arrangement direction so as to obstruct the flow of blow-by gas, and is also provided at a position offset from the valve mechanism in the cylinder arrangement direction. Preferably, the outer protruding end lPs of the rib member is located below the upper end outline of the valve mechanism, that is, the two outlines overlap when viewed from one end in the cylinder arrangement direction.

(Function) Accordingly, in the present invention, the locker chamber is partitioned into a state in which the valve train valve member protrudes in the opposite direction at a position shifted in the cylinder arrangement direction.

For this reason, the blow-by gas has no choice but to meander up and down while detouring around the valve mechanism valve member in the opposite direction.
The transition occurs while repeatedly colliding with the outer surface of the constituent members of the valve mechanism or the inner wall of the cylinder head cover. Due to this transition, the oil mist floating in the blow-by gas may collide with and adhere to structures in the locker room when the blow-by gas collides, or when the blow-by gas detours, the gas flow due to the inertial force due to the mass difference. By separating from the gas and adhering to the structure, it is separated from the blow-by gas.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, a locker chamber 4 that accommodates a valve mechanism 3 is defined by a cylinder head 1 and a cylinder head cover 2 that covers the top surface of the cylinder head 1. The valve mechanism 3 includes a camshaft 5 disposed at the inner bottom of a locker chamber 4, a rocker shaft 6 disposed above and to the left and right of the camshaft 5, a rocker arm 7 supported by the rocker shaft 6, and the like. , which opens and closes the intake valve 8 and the exhaust valve 9. The camshaft 5 is rotationally driven synchronously by a crankshaft (not shown) via a timing gear 10 fixed to its front end and a chain 11 wound around the gear 10.

Blow-by gas leaking from the combustion chamber into the crank chamber is pushed out of the crank chamber by the downward movement of the piston.
It ascends inside the chain case 12 that covers the outer surface of the chain 11 and reaches the locker room 4. In order to separate and recover the oil mist contained in the blow-by gas, the inside of the locker chamber 4 is equipped with a valve train 11113 disposed in the cylinder head 1 and a cylinder head cover 2, as shown in FIG.
It is divided into a plurality of parts along the cylinder arrangement direction by a pipe member 13 provided on the inner surface of the cylinder. Said rib member 1
3 protrudes downward toward the space between adjacent valve mechanisms 3, and extends from one opening side edge of the cylinder head cover 2 toward the other in a state perpendicular to the cylinder arrangement direction. In other words, against the blow-by gas moving inside the locker chamber 4 along the axial direction of the camshaft 5,
It protrudes downward to cross the flow orthogonally and obstruct it. As shown in FIG. 2, the rib member 13 is large enough to overlap the outer line of the rib member 13 and the outer line of the rocker arm 7 vertically when viewed from the cylinder arrangement at the left and right corners of the inner surface of the cylinder head cover 2. It is overhanging.

Roughly speaking, an oil separator 15 is provided near the rear end of the upper surface of the cylinder head cover 2 (the side farthest from the chain case 2) in order to collect a small amount of oil mist remaining in the blow-by gas.

As shown in Figure 3, the oil separator 15 is
The partition is formed by a convex partition wall 15a that opens downward and a cover 16 that closes the opening edge of this partition, and the inside is partitioned into three front and rear chambers by a partition wall 15b perpendicular to the cylinder arrangement direction. Partition wall 1 along the cylinder arrangement direction
It is divided into multiple parts by 5C. The blow-by gas enters the oil separator 15 through gas inlets 17 opened on one side of the chambers at both front and rear ends, flows into the central chamber in a U-turn shape, and is taken out to the outside through an outlet 18 provided in this chamber. be done. A vibrator 19 is connected to the outlet 18 and communicates with the intake passage.

Further, as shown in FIG. 3, a breather chamber 20 for taking in fresh air is defined on the inner surface of the front end of the cylinder head cover 2. It passes through the outside air.

Therefore, in the above embodiment, the blow-by gas moves from the chenoke case 12 side to the oil separator 15 side in the locker room 4.

At this time, the valve mechanism 3 and the rib member 13 move the locker chamber 4 back and forth in the cylinder arrangement direction. ! Since the blow-by gas is divided into two sections, the blow-by gas is distributed between the valve train @3 and the rib member 1.
3 alternately in opposite directions and meandering upward and downward, and repeatedly collides with the rocker arm 7 and the cylinder, the rad cover 2 and the rib member 13. Due to this collision between the structures in the locker room 4 and the blow-by gas, the oil mist contained in the blow-by gas adheres to the structures and is separated from the blow-by gas. Furthermore, when the blow-by gas bypasses the rib member 13 and the like, only the oil mist moves straight due to the inertia force applied to the blow-by gas flow, separates from the blow-by gas, and adheres to nearby structures. In this way, most of the oil mist contained in the blow-by gas is separated before it flows into the oil separator lake 15. Therefore, the oil separator 15 only needs to separate a small amount of remaining oil mist, and its oil separation capacity may be small. In some cases, the oil separator 15 may be omitted. The oil mist separated within the locker chamber 4 accumulates on the inner bottom of the locker chamber 4, and then flows down to the crank chamber and is collected and reused.

In addition, in the above embodiment, a so-called 5ot-+C type valve train (a number of valves were explained, but it is not necessarily necessary.
The present invention is also applicable to DOHC type and OHV type.

Further, the rib member 13 does not need to be orthogonal to the cylinder arrangement direction, and it is sufficient that the rib member 13 is formed as a series in a direction that obstructs the flow of blow-by gas while crossing it, that is, in a direction that is substantially perpendicular to the flow. .

Roughly speaking, in the above embodiment, the outline of the rib member 13 and the outline of the valve mechanism 3 are set to overlap only partially, but in some cases, the outline may be set so that most of the outlines overlap. It's okay.

(Effects of the Invention) As described above, according to the present invention, when the blow-by gas passes through the locker chamber, the blow-by gas is forcibly detoured in the opposite direction by the valve mechanism and the rib member, and moves in a vertically meandering state. Therefore, it is possible to directly and effectively separate oil within the locker room and reduce oil consumption.

In addition, by using the locker room with a sufficiently large internal space,
Moreover, since oil separation is performed using the existing valve mechanism, compared to conventional oil separation methods, oil separation can be performed reliably without increasing engine weight or significantly increasing manufacturing costs. Furthermore, when an oil separator is separately provided on the cylinder head cover, its oil separation capacity can be reduced, which is advantageous in that restrictions on the layout of the oil separator can be reduced during design.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, in which FIG. 1 is a longitudinal side view schematically showing the internal structure of a locker room, and FIG.
The figure is A-Aa! in Figure 1! The sectional view and FIG. 3 are bottom views of the cylinder head cover. 2... Cylinder head cover, 3... Valve mechanism, 4
...Locker room, 13... Lip member, 17... Outlet. murmur゛-゛-i'

Claims (1)

[Claims] (1) In an engine in which the cylinder head cover is provided with a blow-by gas outlet, and the blow-by gas is led out from the outlet via a locker chamber partitioned by the cylinder head cover, the cylinder array is arranged on the inner surface of the cylinder head cover. A rib member extending in a direction substantially perpendicular to the direction is protruded, and the rib member is disposed in the locker chamber at a position offset from the valve mechanism disposed in the cylinder head in the cylinder arrangement direction. The engine cylinder head cover structure is characterized by: