JPH0113779Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention provides a gas-liquid separation device for the blowby gas when extracting the blowby gas in the cylinder head cover of an internal combustion engine to a blowby gas processing section such as an intake system. It is related to.

[Conventional technology]

When extracting the blowby gas in the cylinder head cover of an internal combustion engine to a blowby gas processing section such as an intake system, a gas-liquid separation device for separating oil in the blowby gas is integrally provided in the cylinder head cover. has been well known for a long time.

In the conventional gas-liquid separation device that is integrally provided with the cylinder head cover, a frame-shaped side frame wall is integrally formed on the inner surface of the cylinder head cover, and the lower surface of the side frame wall is formed integrally with the cylinder head cover. A bottom plate that closes the inside of the side frame wall is joined to form a gas-liquid separation chamber that communicates with the inside of the cylinder head cover. By providing a gas-liquid separation partition plate in the gas-liquid separation chamber to form a zigzag passage from the blow-by gas inlet to the blow-by gas outlet to the gas-liquid separation chamber, oil in the blow-by gas can be removed. A so-called labyrinth type device configured to separate the gas from the blow-by gas flowing into the gas-liquid separation chamber from the blow-by gas inlet at one end of the gas-liquid separation chamber without forming a zigzag passage or the like in the gas-liquid separation chamber. There is a positive displacement type in which the oil content in the blow-by gas is separated by temporarily retaining it in a liquid separation chamber.

These conventional gas-liquid separation devices have a bottom plate attached to the lower surface of the side frame wall that forms the periphery of the gas-liquid separation chamber, thereby making the inside a gas-liquid separation chamber. When joining the bottom plate to the lower surface of the side frame wall, if there is a gap at the joint between the side frame wall and the bottom plate, the blow-by gas containing lubricating oil, which is constantly being scattered in large quantities into the cylinder head cover, will flow through this gap. In case of leakage inflow and maze type,
The blow-by gas flows out from the outlet without being subjected to the gas-liquid separation effect by the gas-liquid separation partition plate in the gas-liquid separation chamber.In addition, in the case of a positive displacement type, the blow-by gas does not remain in the gas-liquid separation chamber. Since it flows out from the outlet, the amount of lubricating oil carried away by the blowby gas to the blowby gas processing section increases, which not only increases the amount of lubricating oil consumption but also causes deterioration of exhaust gas. Become.

Therefore, in conventional gas-liquid separators, as described in, for example, Japanese Utility Model Application Publication No. 59-43613,
When joining the bottom plate to the side frame wall that is integrally formed on the lower surface of the cylinder head cover, a sealing gasket is inserted into the joint surface of the side frame wall and the bottom plate to ensure the joint. This is to prevent blow-by gas from leaking into the gas-liquid separation chamber.

[Problem that the invention attempts to solve]

However, when joining the bottom plate to the side frame wall that is integrally formed with the cylinder head cover, inserting a gasket at the joint between the side frame wall and the bottom plate requires a large number of parts. This not only increases the manufacturing cost, but also causes problems in that a gasket must be inserted each time the bottom plate is attached to the side frame wall, which increases the amount of work required.

In the case where the gas-liquid separation chamber is formed by joining the bottom plate to the lower surface of the side frame wall that is integrally formed with the cylinder head cover, the present invention provides a method for connecting the side frame wall and the bottom plate. The problem of the prior art is overcome by allowing surfaces to be reliably sealed without the use of gaskets.

[Means for solving problems]

In order to achieve this objective, the present invention has an enclosure-shaped side frame wall integrally formed on the inner surface of the cylinder head cover, and the lower surface of the side frame wall is designed to close the inside of the side frame wall. After joining the bottom plate, the inside of it is
In the gas-liquid separation device for blow-by gas formed in a gas-liquid separation chamber having a blow-by gas inlet communicating with the cylinder head cover and a blow-by gas outlet to the blow-by gas processing section, the side frame A sealing piece that comes into contact with or approaches the inner circumferential surface of the wall is provided so as to extend along the periphery of the side frame wall, and a portion where the sealing piece approaches the inner circumferential surface of the side frame wall; A volume enlarged portion is formed between the bottom plate and the joint portion to the lower surface of the side frame wall so as to extend along the periphery of the side frame wall.

[Functions and effects of the idea]

With this configuration, the blow-by gas leaking into the gas-liquid separation chamber from the joint of the bottom plate to the side frame wall first passes through the narrow gap at the joint of the bottom plate to the side frame wall, and then flows inside the narrow gap. It reaches the volume expansion part formed in , expands here, and then
It passes through a narrow gap where the seal piece contacts or approaches the inner circumferential surface of the side frame wall.

In other words, the blow-by gas that leaks and flows into the gas-liquid separation chamber from the joint surface of the bottom plate with the side frame wall can be seen from the joint of the bottom plate with the side frame wall and the inside of the side frame wall. Both narrow gaps at the contact or approach portion of the seal piece with the peripheral surface and the volume expansion portion located between these narrow gaps are arranged alternately,
This exhibits the action of the so-called labyrinth packing described in the ``Mechanical Engineering Handbook'' published by the Japan Society of Mechanical Engineers, for example, so that the blow-by gas containing lubricating oil in the cylinder head cover is transferred to the joint surface of the bottom plate against the side frame wall. It is possible to reliably reduce leakage and inflow into the gas-liquid separation chamber, and also to separate oil contained in the blow-by gas that leaks and inflow into the gas-liquid separation chamber from the joint surface of the bottom plate to the side frame wall. It can be done.

Therefore, according to the present invention, it is possible to omit the gasket that was conventionally inserted at the joint between the side frame wall and the bottom plate, so the number of parts is reduced.
Not only can manufacturing costs be reduced, but the labor required for assembly can also be reduced. Moreover, by not requiring a gasket at the joint between the side frame wall and the bottom plate, the bottom plate can be attached to the side frame wall using multiple bolts. There is no need to fasten the bottom plate to the side frame wall, which has the effect of simplifying the attachment of the bottom plate to the side frame wall.

〔Example〕

Hereinafter, a drawing will be explained in which an embodiment of the present invention is applied to a positive displacement gas-liquid separation device of a positive displacement gas-liquid separation device and a labyrinth-type gas-liquid separation device. This figure shows a cylinder head cover attached to the upper surface of a cylinder head (not shown) so as to cover the valve mechanism on the upper surface. A side frame wall 3 formed into an enclosure frame shape is integrally molded as shown in FIG. A positive displacement air cylinder communicates with the cylinder head cover 1 through a blow-by gas inlet (not shown), and has a blow-by gas outlet 5 for blow-by gas treatment such as an intake manifold (not shown) in an internal combustion engine. It is formed in the liquid separation chamber 6.

In this case, the bottom plate 4 is fastened to the side frame wall 3 with a plurality of bolts 7 as shown in FIG. 2, or is integrally protruded from the side frame wall 3 as shown in FIG. It may be installed by simply fitting the snap-type pins 8 into the holes 9 in the bottom plate 4.

A seal piece 10 is provided on the upper surface of the bottom plate 4 and extends along the periphery of the side frame wall 3, the upper end of which touches or approaches the inner circumferential surface of the side frame wall 3. An enlarged volume portion 11 is provided between the portion where the seal piece 10 approaches the inner circumferential surface of the side frame wall and the joint portion of the bottom plate 4 with the lower surface of the side frame wall 3.
is formed to extend along the periphery of the side frame wall 3.

The enlarged volume portion 11 may be formed as a recess at the inner circumferential corner of the lower surface of the side frame wall 3 as shown in FIGS. 1 and 2, but as shown in FIG. Needless to say, it may be formed by recessing a part thereof, or may be formed by other means.

Due to the existence of this volume expansion part 11, the blow-by gas leaking into the gas-liquid separation chamber 6 from the joint of the bottom plate 4 to the side frame wall 3 is first After passing through the gap, it reaches the volume expansion part 11 formed inside the gap and expands there, and then squeezes and passes through the narrow gap where the seal piece 10 contacts or approaches the inner peripheral surface of the side frame wall 3. In other words, when the blow-by gas leaking into the gas-liquid separation chamber 6 from the joint surface of the bottom plate 4 with respect to the side frame wall 3 is viewed from the direction of leakage and inflow, the bottom plate 4 with respect to the side frame wall 3 is a narrow gap at the joint part and the part where the seal piece 10 contacts or approaches the inner circumferential surface of the side frame wall 3;
Volume expansion part 11 located between these two narrow gaps
are lined up alternately, and this acts as a so-called labyrinth packing, so that the blow-by gas containing lubricating oil in the cylinder head cover 1 is released from the joint between the side frame wall 3 and the bottom plate 4 into gas and liquid. It is possible to reduce leakage and inflow into the separation chamber 6, and also to separate oil contained in the blow-by gas that leaks into the gas-liquid separation chamber from the joint surface of the bottom plate to the side frame wall.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional front view, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is an enlarged view of the main part of another embodiment. 1...Cylinder head cover, 2...Ceiling plate,
3... Side frame wall, 4... Bottom plate, 5... Blowby gas outlet, 6... Gas-liquid separation chamber, 7... Bolt, 8...
...Snap type pin, 10...Seal piece, 11...
Volume expansion section.

Claims (1)

[Scope of utility model registration request] An enclosing frame-shaped side frame wall is integrally formed on the inner surface of the cylinder head cover, and a bottom plate that closes the inside of the side frame wall is joined to the lower surface of the side frame wall. A blowby gas gas-liquid separation device formed in a gas-liquid separation chamber having a blowby gas inlet communicating with a head cover and a blowby gas outlet to a blowby gas processing section,
A seal piece is provided on the upper surface of the bottom plate so as to extend along the periphery of the side frame wall, and the seal piece abuts or approaches the inner peripheral surface of the side frame wall. An enlarged volume portion is formed between a portion approaching the inner circumferential surface and a joint portion of the bottom plate to the lower surface of the side frame wall so as to extend along the periphery of the side frame wall. Blow-by gas gas-liquid separation equipment.