JPS6349559Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cylinder head cover for an internal combustion engine, and more particularly to an improvement in a sealing member.

Prior Art In recent years, in order to reduce the weight of the engine body, a structure in which the cylinder head cover is formed from a thin iron plate has been proposed. Now, in an engine having an overhead camshaft mechanism, in order to separate the blow-by gas that has entered the head cover from the engine oil scattered by the rotation of the camshaft, the first and second casings, which are open on the engine head side, are connected to each other. These casings are fitted so that their openings match to form a separation chamber between the bottoms of the casings, and the opening side is fixed to the cylinder head. That is, blow-by gas and oil are separated within this separation chamber. However, in a head cover having such a configuration, if there is a gap between the first and second casings, engine oil will flow down through this gap, so all of this oil is collected into the cylinder head, and A sealing member is required to reliably isolate the inside and outside of the head cover.

Purpose of the invention In view of the above points, the present invention was made with the aim of recovering all the engine oil into the cylinder head and also ensuring a seal between the head cover and the cylinder head.

Structure of the invention The annular sealing members of the cylinder head cover according to the invention are fitted into the annular gaps formed between the edges of the first and second casings, and are formed at predetermined intervals on the inner circumferential side. The protrusions contact the outer circumferential surface of the second casing, and the portions between the protrusions are separated from the outer circumferential surface, and the outer circumferential portion is in close contact with the inner circumferential surface of the first casing over the entire circumference. It is characterized by

Example The present invention will be explained below with reference to the illustrated embodiments.

Referring to FIG. 1, cylinder head cover 1
is fixed to the cylinder head 2 by a bolt 3 provided on the cylinder head 2. The head cover 1 is constructed by combining several box-shaped casings made of, for example, press-formed thin iron plates. That is, a box-shaped second casing 12, which is open on the cylinder head 2 side and whose ceiling wall is bent inward, is fitted into a box-shaped first casing 11 that is open on the cylinder head 2 side. These first and second casings 11,1
The two side wall parts 13 and the ceiling part 14 are each fixed to each other by spot welding. The edge 15 of the first casing 11 is bent outward over the entire circumference, and an annular gap 17 is formed between this edge 15 and the edge 16 of the second casing 12.

An annular seal member 20 made of an elastic material such as rubber is fitted into the annular gap 17, and as shown in FIG. be done. This protrusion 21
As shown in Fig. 4, these protrusions 2
As shown in FIG. 5, the portion 22 between the two portions 1 and 1 is formed into a flat shape, and a tapered surface 26 is formed along the entire circumference at the lower edge. Seal member 20
When the projections 21 are fitted into the annular gap 17, as shown in FIG. The outer circumferential portion 23 and the upper portion 24 are in close contact with the inner circumferential surface of the first casing 11 over the entire circumference.

In this manner, by providing the protrusion 21, the outer circumferential portion 23 is brought into close contact with the first casing 11, while the flat portion 22 and the second casing 12 are closely attached to each other.
Since a gap is formed between the first and second
Oil A that has entered between the casings 11 and 12 is returned into the cylinder head through this gap. That is, normally the first and second casings 11,1
Since the manufacturing accuracy of casing 2 is not very high, a slight gap 25 is formed between the first and second casings 11 and 12 after spot welding, as shown in FIG. All oil passing through this gap 25 is collected into the cylinder head. Further, in the assembly process, when the seal member 20 is installed between the first and second casings 11 and 12 and transported to the cylinder head 2, the seal member 20 is firmly fixed within the annular space 17 by the protrusion 21. There is no risk of it coming off from the head cover 1.

Now, the upper part of the second casing 12 is recessed to be separated from the first casing 11, except for the part where the ceiling part 14 contacts the first casing 11,
The floor portion 30 of this recessed portion and the first casing 1
A first separation chamber 31 is formed between the two. Floor part 3
0 is gently sloped, and a recess 32 is formed at the lowest point, and a first oil drain hole 33 is formed in this recess 32.
is bored, and furthermore, a first hole is formed adjacent to this recess 32.
An intake hole 34 is formed. A box-shaped third casing 35 is provided within the first separation chamber 31 . This third casing 35 is fixed to the upper part of the first casing 11, and the floor part 36 is close to the floor part 30 of the second casing 12 and is inclined, and has a second oil drain hole 37 and a second oil intake in the lowest part. A hole 38 is drilled. Thus, a second separation chamber 39 is formed within the third casing 35, and a fourth casing 40 is provided within this separation chamber 39. This fourth casing 4
0 is also fixed to the upper part of the first casing 11 in the same way as the third casing 35, and the floor part 41 is close to the floor part 36 of the third casing 35, and the floor part 3
6 and an opening 42 is formed in the lowest side. However, the fourth casing 4
A third separation chamber 43 is formed within 0.

In the upper part of the first casing 11 that forms the third separation chamber 43, an intake (not shown) is connected via a PCV valve 44 configured to suck out the blow-by gas in the head cover 1 using the engine's intake negative pressure. An exhaust hole communicating with the manifold and an intake hole 45 communicating with the air cleaner are provided.

The second, third and fourth casings 12, 3
5 and 40, the oil is separated from the separation chamber 3.
Although it becomes difficult for the oil to enter the cylinder head 1, 39, and 43, even if it does, it is separated from the blow-by gas in the following manner, the blow-by gas is exhausted through the PCV valve 44, and the oil is returned to the cylinder head 2. In FIG. 1, the blow-by gas generated inside the engine enters the first separation chamber 31 through the first intake hole 34 together with mist oil as shown by the white arrow in the figure, and then enters the second separation chamber 31 through the first intake hole 34. It flows into the second separation chamber 39 through the inlet hole 38 . During this time, the oil is separated, and the oil that has fallen onto the floor 30 of the second casing 12 is collected into the cylinder head 2 through the first oil drain hole 33, as shown by the black arrow in the figure, and is also collected into the cylinder head 2 from the third casing. The oil that has fallen onto the floor 36 of the second casing 12 passes through the second oil drain hole 37 and then the first oil drain hole 33 of the second casing 12.
The water is returned to the cylinder head 2 via the cylinder head 2. On the other hand, the blow-by gas is exhausted from the opening 42 through the third separation chamber 43 and the PCV valve 44, and the oil separated in the third separation chamber 43 is
Returns from the opening 42 to the second separation chamber 39 and drains the oil through the oil drain hole 3
7, 33 and is recovered to the cylinder head 2.

In the above separation action, the oil that has entered the gap 25 between the first and second casings 11 and 12 (see FIG. 6) without passing through the oil drain holes 37 and 33,
As described above, the seal member 20 and the second casing 1
2 to the cylinder head 2, whereby all the separated oil is recovered to the cylinder head 2.

The bolts 3 are attached to both ends of the first and second casings 11 and 12, respectively. Both ends 51 of the first casing 11 are bent upward, while both ends 52 of the second casing 12
are bent downwards, and these ends 51, 52
Holes 53 and 54 are drilled in the holes 53 and 54 through which the bolts 3 pass. The bolt 3 protrudes upward from the first casing 11, and a nut 55 is screwed onto the protruding portion of the bolt 3 via a seal washer 56 having an elastic member. Therefore, head cover 1 is connected to cylinder head 2.
Fixed.

Note that the cross-sectional shape of the protrusion 21 of the annular seal member 20 does not necessarily have to be mountain-shaped as shown in FIGS. 4 and 6, but may be rectangular or any other shape. .

Effects of the invention As described above, according to the invention, the first and second
Since the oil that has entered between the casings flows to the cylinder head through between the seal member and the second casing, it is possible to recover all the oil in the head cover to the cylinder head. Also,
Since the outer circumferential portion of the annular seal member is in close contact with the inner circumferential surface of the first casing over the entire circumference, the head cover and the cylinder head can be reliably sealed. Furthermore, some of the oil passing through the inner circumferential side of the annular seal member permeates into this seal member.
As a result, the sealing member expands and comes into closer contact with the inner circumferential surface of the first casing, thereby achieving the effect that the sealing between the head cover and the cylinder head can be performed more reliably.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a head cover showing an embodiment of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, Fig. 3 is a plan view showing an annular seal member, and Fig. 4 is a sectional view of a head cover showing an embodiment of the present invention.
The figure is a sectional view taken along the - line in Fig. 3, Fig. 5 is a sectional view taken along the - line in Fig. 3, and Fig. 6 shows a state in which the annular seal member is fitted between the first and second casings. FIG. 1... Cylinder head cover, 2... Cylinder head, 11... First casing, 12... Second
casing, 17... annular space, 20... annular sealing member, 21... protrusion;

Claims (1)

[Scope of utility model registration request] a first casing with an opening on the cylinder head side; a second casing with an opening on the cylinder head side and fitted to the inner peripheral side of the first casing;
An annular seal member made of an elastic material is fitted into an annular gap formed between the opening edges of the first and second casings, and the annular seal member is arranged at a predetermined interval on the inner circumferential side. The protrusions formed at each contact abut the outer circumferential surface of the second casing, and the portions between these protrusions are separated from the outer circumferential surface, and the outer circumferential portion contacts the inner circumferential surface of the first casing over the entire circumference. A cylinder head cover for an internal combustion engine, which is characterized by being in close contact with the cylinder head cover.