JPH0231532Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an oil separator for separating blow-by gas and oil in a PCV system, and particularly relates to the structure of an oil separator in a PCV system in a double-overhead camshaft engine.

[Conventional technology] PCV that recirculates blow-by gas to the intake system
(Positive crankcase ventilation)
In the system, the path of blow-by gas is typically from the crankcase through the cam chamber to the intake system. Since the blow-by gas from the crankcase contains a large amount of oil mist, and a large amount of oil is scattered in the cam chamber, the oil must be separated from the blow-by gas before being sent to the intake system. No.

The oil separator that separates oil from this blow-by gas is usually installed inside the head cover of the cam chamber, but various oil separator structures have been proposed (for example, in
No. 152313, Utility Model No. 56-149013, Utility Model No. 58-2344
No., Utility Model No. 58-79009, Utility Model No. 58-108215,
Utility Model No. 59-94106).

[Problems to be solved by the invention] However, because the conventional oil separator was installed on the camshaft, and the blow-by gas intake was located directly above the cam, a large amount of oil scraped up by the cam was transferred to the oil separator. There was a risk that the oil could get into the oil, making it difficult to separate the oil efficiently. Particularly when driving at high speeds, the camshaft rotates quickly, which increases the amount of oil that is thrown up and thrown away, and the centrifugal force caused by the rotation of the cam makes it easier for the oil thrown away to enter the oil separator, making it difficult to separate it properly. . In addition, since the direction of the oil separator's blow-by gas intake was in the same direction as the cam rotation direction, the oil scraped up by the cam easily entered the oil separator, making it difficult to achieve good oil removal performance. was difficult.

In addition, if the blow-by gas inlet is installed at the end of the head cover, the oil level may reach the blow-by gas inlet during sharp turns, climbing, sudden acceleration and deceleration, etc., or the oil may leak onto the inner wall of the head cover. There is also a risk that the oil may enter the blow-by gas intake port through the air, causing a sudden increase in the amount of oil carried away to the intake system.

In this conventional structure where the blow-by gas intake port is provided directly above the cam and the blow-by gas intake direction is the cam rotation direction, a large amount of oil enters the oil separator, and the blow-by gas is not sufficiently separated into gas and liquid. I had some concerns. Another problem was that the amount of oil entering the PCV system was likely to increase, especially during harsh driving conditions such as high speeds, sharp turns, climbing, sudden acceleration and deceleration, etc.

In order to improve the above-mentioned problems, the applicant previously proposed that the blow-by gas intake port of the oil separator provided in the head cover be located at a position intermediate and adjacent to the intake manifold side camshaft and the exhaust manifold side camshaft. A guide plate was provided at an intermediate position of the plug tube, and a guide plate was provided below the blow-by gas intake port to guide the blow-by gas to the blow-by gas intake port, and the blow-by gas intake direction of the guide plate was made parallel to the axis of the camshaft. structure is proposed. (Akira Jigan
No. 59-124698 (Utility Model Application Publication No. 61-39422)).

Although this proposal has significantly reduced the amount of oil entering the PCV system, there is still room for improvement in the oil separator's oil removal performance. Furthermore, in the structure proposed above, the PCV path is made into a labyrinth within the limited space inside the head cover, so there remains the problem that it may be difficult to secure a sufficient cross-sectional area for the blow-by gas passage. .

In order to improve the problems of the prior art and the remaining problems of the previously proposed structure, the present invention is capable of preventing the intrusion of oil blown away by the cam, and even under severe driving conditions. To provide an oil separator structure capable of suppressing the amount of oil intrusion, greatly improving oil cutting performance, and simplifying the gas passage structure.

[Means for Solving the Problems] In order to achieve this objective, in the oil separator of the PCV system of the present invention, the oil separator of the PCV system installed in the head cover of a double overhead camshaft engine has the following features: A blow-by gas intake port is provided at an intermediate position between the intake manifold side camshaft and the exhaust manifold side camshaft, and at an intermediate position between adjacent plug tubes. A guide plate is further provided at the bottom of the blow-by gas intake port to guide the blow-by gas to the blow-by gas intake port as an oil separator, and the blow-by gas intake direction of this guide plate is oriented parallel to the axis of the camshaft. In addition, the opening direction is only on the side opposite to the position of the blowby gas hole in the cylinder head that guides blowby gas from the crankcase side onto the cylinder head.

[Function] In the cam chamber, a large amount of oil is blown away by the cam portion of the camshaft in the direction of cam rotation and above the cam, but the blow-by gas intake is located between the two camshafts and between the plug tubes. Therefore, the blow-by gas intake port is removed from the position in the rotational direction of the cam and from the position directly above the cam. This blow-by gas intake port is blocked from a direct line from the cam by the lower guide plate, and the blow-by gas intake direction of the guide plate is set perpendicular to the cam rotation direction. This prevents the blown oil from directly entering through the blow-by gas intake port of the oil separator. In addition, a portion of the blow-by gas collides with the plug tube in that direction before entering the blow-by gas intake portion of the guide plate, so that a certain amount of mist-like oil is also removed at the time of collision. Therefore, the amount of oil that reaches the blow-by gas intake port of the oil separator is kept small, and the amount of oil that enters the PCV system is reduced.

In addition, the blow-by gas intake port is located between the plug tubes and is located away from the inner wall surface of the head cover, so even if there is oil flowing through the inner wall surface or the oil level fluctuates depending on the driving conditions, the blow-by gas intake can be easily removed. The amount of oil entering from the inlet does not increase. Therefore, even under severe driving conditions, the amount of oil intrusion can be suppressed.

Furthermore, the blowby gas that rises from inside the crankcase to the cylinder head through the blowby gas hole flows toward the oil separator, but since the opening direction of the guide plate is only in the opposite direction to the blowby gas hole, the blowby gas does not flow. The blow-by gas makes a U-turn and enters the guide plate to reach the blow-by gas intake port. Therefore, the blow-by gas is prevented from entering in a straight line, and the oil is already sufficiently separated at the stage of entering the oil separator, improving the gas-liquid separation performance of the oil separator.

[Embodiments] Hereinafter, preferred embodiments of the oil separator of the PCV system of the present invention will be described with reference to the drawings.

1 to 3 show an oil separator for a PCV system according to an embodiment of the present invention, which is applied to a 4-cylinder, 4-valve double overhead camshaft engine. In the figure, numeral 1 indicates a head cover attached to the upper part of the cylinder head 2, numeral 3 indicates a camshaft on the intake manifold side, and numeral 4 indicates a camshaft on the exhaust manifold side. An oil separator 5 of the PCV system is installed inside the head cover 1. The oil separator 5 is
It consists of two rooms, PCV room 6 and PCV room 7.
A PCV pipe or
PCV valve 8 is connected.

The PCV chamber 6 and the PCV chamber 7 are partitioned so that they can communicate with each other by a rib 9 hanging down between them.
A blow-by gas intake port 10 having a punch hole structure is provided at the lower part of the PCV chamber 7, and the blow-by gas enters the PCV chamber 7 from here.

The blow-by gas intake port 10 of the oil separator 5 is located at an intermediate position between the intake manifold side camshaft 3 and the exhaust manifold side camshaft 4, and adjacent plug tubes 11, 1.
It is provided at an intermediate position between the two. Therefore, the blow-by gas intake port 10 is located between the two camshafts 3 and 4 and between the cams 13 and 4 of the camshafts 3 and 4.
14 and between the rotating surfaces of 15 and 16. Further, the blow-by gas intake port 10 is set above the center of the camshaft shaft.

At the lower part of the blow-by gas intake port 10, there is further provided a blow-by gas intake port 10 for supplying blow-by gas.
A guide plate 17 is provided to guide the user. Information board 17
is provided so as to cover the blow-by gas intake port 10 from below. The interior of the guide plate 17 also communicates with the PCV chamber 7 side, and the lower surface of the PCV chamber 7 is configured to be an inclined surface so that oil flows from the PCV chamber 7 side to the guide plate 17 side.

The flow-by gas intake direction of the guide plate 17 is oriented parallel to the axes of the camshafts 3 and 4. This guide plate 17 extends to a position near the plug tube 11, and the blow-by gas intake port 18 of the guide plate 17 itself is connected to the blow-by gas of the cylinder head 2 which guides the blow-by gas from the crankcase side onto the cylinder head 2. It is opened only on the side opposite to the position of the hole 19.

Note that the diagram only shows the #1 and #2 cylinders among the four cylinders, but the #3 and #4 cylinders have a similar structure and are symmetrical to the structure shown in the diagram. .

The operation of the embodiment device configured as described above will be explained below.

Blow-by gas hole 1 from inside the crankcase
The blow-by gas rising onto the cylinder head 2 through the oil separator 9 flows toward the oil separator 5. When this blow-by gas enters the guide plate 17, since the opening direction of the intake port 18 of the guide plate 17 is only in the opposite direction to the blow-by gas hole 19, the blow-by gas that has flowed into the guide plate 17 in a straight line. Instead of entering the guide plate 17, you will make a U-turn and enter the guide plate 17. Gas can make a smooth U-turn, but oil cannot make a smooth U-turn due to its inertia; gas and liquid are already separated when it enters the guide plate 17, and the blow-by gas intake port 10 has a small amount of oil. gas is sent.

In addition, the blow-by gas intake port 10 is located between the two camshafts 3 and 4 through the plug tube 1.
This position is set at an intermediate position between cams 13, 14, 15, and 16, and is a position that avoids being directly above the cams 13, 14, 15, and 16, and avoiding the position of the rotating surface of the cam. Therefore, the oil scraped up by the cams 13, 14, 15, 16, and the cams 13,
Any of the oil swept away by the centrifugal force due to the rotation of the cylinders 14, 15, and 16 becomes difficult to reach the blow-by gas intake port 10 directly. Since the guide plate 17 is provided to cover the blow-by gas intake port 10 from below, the blow-by gas intake direction of the guide plate 17 is in the cam rotation direction.
That is, since the direction is set perpendicular to the direction in which oil is blown away by centrifugal force due to the rotation of the cam, the blown oil does not directly reach the blow-by gas intake port 10. Therefore,
The amount of the blown oil that enters the oil separator 5 is suppressed to a large extent, and a large amount of oil is prevented from entering even during high-speed rotation.

Further, since the intake port 18 of the guide plate 17 is provided near the plug tube 11, a portion of the blow-by gas collides with the plug tube 11. Therefore, even if the oil is in the form of a mist, it adheres to the wall surface of the plug tube at the time of collision and flows down, and some of the oil is removed before entering the oil separator 5.

In addition, the blow-by gas intake port 10 is located between the plug tubes and is located away from the inner wall surface of the head cover 1, so that blow-by gas may occur near the inner wall surface of the head cover during sharp turns, sudden acceleration/deceleration, climbing, etc. It also prevents oil from entering due to fluctuations in the oil level or oil flowing through the inner wall surface.

Furthermore, since the height of the blow-by gas intake port 10 is set higher than the center of the camshaft shaft, oil accumulated in the head will not jump into the blow-by gas intake port 10 due to oil level fluctuations.

From the blow-by gas intake port 10 like this
The blow-by gas that has flowed into the PCV chamber 6 has a flow path rapidly expanded in the PCV chamber 6, so that its flow velocity is temporarily lowered, and then its velocity is increased by the restriction of the ribs 9. The blow-by gas, which is a gas, smoothly follows the increase in speed, but the oil, which is a liquid, does not follow the increase in speed due to its inertia, and the oil is separated from the blow-by gas. Further, the oil that has collided with the inner surface of the rib 9 also falls downward and is returned into the guide plate 17, and is returned from the guide plate 17 to the oil pan side.

The blow-by gas that has flowed into the PCV chamber 7 is
The oil is further separated due to the rapid expansion of the flow path in chamber 7, and the blow-by gas from which the oil has been separated is
It is sent from the PCV pipe or PCV valve 8 to the air cleaner or intake system of the intake manifold. The oil that adheres to the wall inside the PCV chamber 7 is
Due to the slope of the lower surface of the PCV chamber 7, it flows down into the guide plate 17 and returns from the guide plate 17 to the oil pan side.

[Effects of the invention] As explained above, according to the invention, the position of the blow-by gas intake port is specified, the blow-by gas intake direction is separated from the cam rotation direction by the guide plate, and the blow-by gas intake direction of the guide plate is Since the intake direction was directed opposite to the blow-by gas hole,
It is possible to greatly reduce the amount of oil that has already entered the oil separator when the blow-by gas flows into the oil separator, improve the gas-liquid separation function of the oil separator, and supply the desired blow-by gas with a low oil content to the intake system. The effect is that it can be supplied.

As a result of confirming this effect through tests, it was possible to significantly reduce the amount of oil carried away to the intake system compared to conventional devices, and the structure proposed by the applicant earlier (the guide plate opens in both directions) compared to
By setting the blow-by gas intake direction of the guide plate only in the direction opposite to the blow-by gas hole, the amount of oil carried away to the intake system could be reduced to one-eighth. Therefore, by adopting the structure of the present invention, it is possible to significantly reduce oil consumption and improve exhaust purification performance.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a head cover and cam chamber with an oil separator attached to a PCV system according to an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the device shown in Fig. 1 taken along the - line, and Fig. 3 1 is a longitudinal cross-sectional view taken along the - line of the apparatus of FIG. 1. FIG. 1...Head cover, 2...Cylinder head,
3...Intake manifold side camshaft, 4
...Exhaust manifold side camshaft, 5...
...Oil separator, 6,7...PCV chamber, 9...
...Rib, 10...Blow-by gas intake, 11,
12...Plug tube, 13, 14, 15, 1
6...cam, 17...information board, 18...intake port,
19...Blow-by gas hole.

Claims (1)

[Scope of utility model registration request] In the oil separator of the PCV system installed in the head cover of a double-overhead camshaft engine, the blow-by gas intake port of the oil separator is located between the intake manifold side camshaft and the exhaust manifold side camshaft, and between the adjacent plug tubes. In addition, a guide plate is provided below the blow-by gas intake port to guide the blow-by gas to the blow-by gas intake port, and the blow-by gas intake direction of the guide plate is parallel to the axis of the camshaft and An oil separator for a PCV system characterized by having only one side opposite to the blowby gas hole of the cylinder head that guides blowby gas from the case side to the top of the cylinder head.