JPH0229212Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention relates to a blow-by gas reduction device that recirculates blow-by gas in the crankcase of an engine to an intake manifold. The present invention relates to a blow-by gas return device equipped with a ventilation valve that is biased to be pressurized.

(Prior Art) In an automobile engine, in order to prevent the blow-by gas in the crankcase from being released into the atmosphere and to ventilate the inside of the crankcase, the engine is connected to the crankcase or connected to the crankcase. A blow-by gas reduction device (PCV system) is provided, which connects the inside of the cylinder head and the intake manifold to return blow-by gas to the combustion chamber for combustion. Generally, such blowby gas reduction devices include a ventilation valve (hereinafter referred to as
PCV valve) is installed. and,
The PCV valve allows blow-by gas to be inhaled only when the negative pressure in the intake manifold is high, preventing blow-by gas from fouling the air cleaner and carburetor.

Normally, the valve element of such a PCV valve is always biased in the closing direction by a valve spring, and the valve element is moved in the opening direction by negative pressure in the intake manifold. It's like that. That is, the valve body is supported in a floating state. For this purpose, a PCV valve is installed, for example, in the middle of a rubber tube that connects the crankcase and the intake manifold, and
As shown in Publication No. 59-158307, if the valve body is attached to the top side of the intake manifold so that its valve body is pressed upward or sideways, engine vibration etc. As a result, the valve body vibrates and its operation becomes unstable.

Therefore, the PCV valve is usually fixedly attached to a breather chamber or the like provided in the crankcase. Also, Jikko 44
It has also been considered to attach it to the lower surface of the intake manifold, as shown in Japanese Patent No. 11271.
In this way, the valve body is pressed downward in the direction of gravity, and is stably held in the closed state. Therefore,
PCV valve operation becomes stable.

(Problem that the invention attempts to solve) However, in the case where the PCV valve is attached to the breather chamber of the crankcase or the bottom surface of the intake manifold,
Since the PCV valve is located below the intake manifold, there is a problem in that it becomes difficult to perform maintenance, inspection, replacement, etc. of the PCV valve.

Also, since blow-by gas contains moisture, the PCV valve may freeze during cold weather. When the PCV valve freezes like this, the pressure inside the crankcase increases, which has a negative impact on the engine. Therefore,
It is necessary to heat the PCV valve to prevent it from freezing, and to thaw it quickly if it does freeze.

However, in the case where the PCV valve is attached to the breather chamber of the crankcase as described above, the PCV valve is located away from the engine body, so a special means is required to heat it. Also,
Even if the PCV valve is attached to the lower surface of the intake manifold, the PCV valve protrudes below the intake manifold, making it difficult to heat it.

In the case where the PCV valve is attached to the upper surface of the intake manifold as shown in the above-mentioned Japanese Patent Application Laid-Open No. 59-158307, a water jacket is provided on the upper surface of the intake manifold, and the PCV valve is connected to the engine cooling water. However, if the PCV valve is placed on the top side of the intake manifold in this way, the PCV
Not only does the operation of the valve become unstable, but the blow-by gas conduit that leads blow-by gas from the crankcase to the PCV valve becomes long, and there is a possibility that the conduit may freeze. Moreover, since a water jacket is not normally provided on the top surface of the intake manifold, in order to do so, it is necessary to provide a water jacket dedicated to heating the PCV valve on the top surface of the intake manifold.
The structure of the intake manifold becomes complicated and its processing becomes difficult.

The present invention was developed in view of these problems, and its purpose is to prevent the operation of the PCV valve from becoming unstable even when subjected to engine vibration, etc. To enable a PCV valve to be heated without requiring any special means, and to facilitate maintenance and inspection of the PCV valve.

(Means for Solving the Problem) In order to achieve this purpose, the present invention extends the hot water riser normally provided on the intake manifold, and extends the extended portion vertically.
It is characterized by the installation of a PCV valve.
The PCV valve is configured such that its valve body is pressed downward by a valve spring and biased in the closing direction. The lower end of the PCV valve communicates with the crankcase via a blow-by gas conduit, and the upper end communicates with the intake manifold via an inverted U-shaped pipe.

(Function) By attaching the PCV valve to the hot water riser portion of the intake manifold in this manner, the PCV valve is heated by the hot water riser for heating the intake air. Moreover, that
Since the PCV valve is installed so as to pass through the hot water riser, the entire area is heated from the surrounding area, improving its heating efficiency.

Also, install the PCV valve in the vertical direction,
By forcing the valve body in the downward closing direction, the biasing direction coincides with the direction of gravity. Therefore, the valve body is stably held in the closed state, and the PCV
Valve operation becomes stable.

Furthermore, by making the PCV valve pass through the hot water riser extension part up and down, the
The PCV valve will be exposed on the top side of the intake manifold. Therefore, operations such as maintenance, inspection, and replacement become easier. Moreover, since the blow-by gas conduit that guides the blow-by gas from the crankcase is connected to the lower end side of the PCV valve, the conduit can be shortened. Also, the upper end of the PCV valve will be connected to the intake manifold via an inverted U-shaped pipe, so
This also prevents water from accumulating on the downstream side of the PCV valve. As a result, the blow-by gas passage is also prevented from freezing.

(Example) Hereinafter, an example of the present invention will be described using the drawings.

The figures show an embodiment of the blow-by gas reducing device according to the present invention, and FIG. 1 is a partially cutaway schematic side view of an engine equipped with the blow-by gas reducing device, and FIGS. are a top view, a rear view, and a side view of the intake manifold of the engine, respectively.

As is clear from FIG. 1, air taken in from an air cleaner 2 is mixed with fuel in a carburetor 3 and supplied to a combustion chamber 1a of an engine body 1 through an intake manifold 4. A hot water riser 5 is provided on the lower surface of the intake manifold 4 to heat the air-fuel mixture to promote vaporization, and cooling water heated in the engine body 1 is guided to the hot water riser 5. ing.

On the other hand, a breather chamber 6 is provided on one side of the crankcase 1b of the engine body 1.
The breather chamber 6 and the intake manifold 4 are connected by a blowby gas passage consisting of a blowby gas conduit 8 and an inverted U-shaped pipe 9 connected via a PCV valve 7.

The engine body 1 is an in-line four-cylinder engine, and its intake manifold 4 consists of a pair of intake pipes 10, 10 connected to a pair of independent carburetors 3, 3, as shown in FIG. ing. Each intake pipe 10 includes an intake introduction pipe 11 and branch pipes 12, 12 branching from the intake pipe 11, and each branch pipe 12, 12, . . . has a common mounting flange 1 at its tip.
3, and by fastening the mounting flange 13 to the side surface of the engine body 1 with bolts, each branch pipe 12, 12, . . .
are connected to the corresponding combustion chambers 1a, 1a, .

As is clear from FIGS. 2 and 3, a pair of intake introduction pipes 11,
A blow-by gas introduction passage 14 is provided which communicates with each of the blow-by gas introduction passages 11, and a blow-by gas introduction port 1 that opens diagonally upward is provided in the center of the introduction passage 14.
5 is provided.

The hot water riser 5 provided on the lower surface of the intake manifold 4 extends from the lower surface of each intake introduction pipe 11, 11 to the lower surface of each branch pipe 12, 12,..., connects them together, and also connects them together. 1
It extends to both sides of 1 and 11. One of the extensions 5a is provided with a hot water inlet 16 for introducing the cooling water sent from the engine body 1, and the other extension 5b is provided with a hot water outlet 17 for returning the cooling water to the radiator. It is provided. In the vicinity of this hot water inlet 16, there is a PCV
A mounting seat 18 for the valve 7 is provided. Second,
As is clear from FIG. 4, the mounting seat 18 is cylindrical, extending in the vertical direction, and having an open top surface.
A female thread for fastening the PCV valve 7 is formed on its inner surface. The outer periphery thereof is surrounded by a hot water riser 5.
In addition, a hot water riser 5 is provided at the bottom of this mounting seat 18.
A connecting pipe 19 protruding from the lower surface of the housing is press-fitted, and a blow-by gas conduit 8 such as a rubber tube is connected to the connecting pipe 19. In this way, the PCV valve 7 is connected to the hot water riser 5.
It is designed so that it can be attached while vertically penetrating the extending portion 5a of the.

As shown in Figure 4, PCV valve 7
The valve body 7a is pressed downward by a valve spring 7b and always urged in the closing direction, and a pipe connection part 7c is provided at the upper part of the valve body 7a. The pipe connecting portion 7c and the blow-by gas inlet 15 of the intake manifold 4 are connected by an inverted U-shaped pipe 9 made of a rubber tube or the like.

In the blow-by gas return device configured in this way, when the engine is under low load, the negative pressure inside the intake manifold 4 increases, and the negative pressure passes through the blow-by gas introduction passage 14 and the inverted U-shaped pipe 9 to the PCV.
Since it is guided to the valve 7, the valve body 7a rises against its own weight and the pressing force of the valve spring 7b, and the PCV valve 7 is opened. Therefore,
After oil is separated from the blowby gas in the crankcase 1b in the breather chamber 6, the blowby gas is transferred to the blowby gas conduit 8, the PCV valve 7, and the reverse U.
It is drawn into each intake introduction pipe 11, 11 from the blowby gas introduction port 15 at the center of the blowby gas introduction passage 14 through the double pipe 9, and is inhaled into each of the branch pipes 12, 12, . . .
evenly distributed to each corresponding combustion chamber 1a, 1
It is guided to a,... and burned. In this way, the inside of the crankcase 1b is ventilated without releasing blow-by gas into the atmosphere.

When the negative pressure inside the intake manifold 4 is low,
The valve body 7a of the PCV valve 7 is lowered, and the PCV valve 7 is closed. At that time, the valve body 7a is subjected to the pressing force exerted by the valve spring 7b as well as
Since the weight of the valve body 7a is applied, the valve body 7a is stably held in that state. Therefore,
The operation of the PCV valve 7 becomes stable.

When the engine is in operation, the cooling water heated by the engine body 1 flows through the hot water inlet 16.
from the hot water riser 5 to the intake manifold 4
PCV valve 7
heat up. Therefore, the PCV valve 7 is prevented from freezing, and even if it is frozen, it is thawed quickly. Furthermore, since the blow-by gas passing through the PCV valve 7 is also heated, freezing of the inverted U-shaped pipe 9 and the like is also prevented. At this time, PCV
Since the valve 7 is attached near the hot water inlet 16 of the hot water riser 5, the heating can be done effectively. The hot water in the hot water riser 5 is led to the radiator from the hot water outlet 17, cooled, and then led back to the engine body 1 for circulation.

Since the PCV valve 7 is attached to vertically penetrate the hot water riser 5, the blow-by gas conduit 8 has a length long enough to connect the connecting pipe 19 protruding from the lower surface of the PCV valve 7 and the breather chamber 6 provided below. It's good if it's good. Therefore, the blow-by gas conduit 8 can be short. Furthermore, since the PCV valve 7 and the blow-by gas inlet 15 of the intake manifold 4 are connected by an inverted U-shaped tube 9, moisture and oil mist in the blow-by gas may adhere to the inner surface of the inverted U-shaped tube 9. However, they will flow down without accumulating inside. The PCV valve 7 is provided in the middle of the blowby gas passage consisting of the blowby gas conduit 8 and the inverted U-shaped tube 9, and since the PCV valve 7 is heated, the blowby gas flowing through the blowby gas passage is disposed in the middle of the blowby gas passage. It will be heated. As a result, the blow-by gas passage is also prevented from freezing.

Furthermore, since the PCV valve 7 is exposed on the upper surface side of the intake manifold 4, its replacement and maintenance and inspection work are facilitated.

In addition, in the above embodiment, the intake manifold 4 is provided with a plurality of intake pipes 10, 10 connected to a plurality of carburetors 3, 3, respectively, but this is not necessarily the case.
For example, it may be a tournament-type intake manifold. In that case, blow-by gas inlet 1
5 may be provided on the upper surface of the intake introduction pipe portion common to all the branch pipes 12, 12, .

Further, in the above embodiment, the blowby gas conduit 8 is connected directly to the crankcase 1b, but in the present invention, the blowby gas is guided from the crankcase 1b to the valve chamber in the cylinder head, and the blowby gas conduit 8 is directly connected to the crankcase 1b. It can also be applied to blow-by gas reduction devices of the type in which the blow-by gas is introduced into the intake manifold 4 through a blow-by gas conduit connected to the cover.

(Effects of the invention) As is clear from the above explanation, according to the invention, the PCV valve is attached to the hot water riser for heating the intake air, which is normally provided in the intake manifold. The PCV valve can now be heated by engine cooling water without the need for a dedicated water jacket, preventing it from freezing.
Moreover, since the PCV valve is attached so as to vertically penetrate the extended portion of the hot water riser, it is surrounded by the hot water riser and is heated from the entire surrounding area. Therefore, the heating can be performed extremely efficiently. Furthermore, since the intake manifold only needs to be provided with a vertical through hole for mounting the PCV valve in the extending portion of the hot water riser, its workability is also improved. Furthermore, since the PCV valve is exposed on the upper surface of the intake manifold, its replacement, maintenance and inspection work, etc. can be easily performed.

The PCV valve has a valve body that is pressed downward by a valve spring and is biased in the closing direction, and is attached to the hot water riser in the vertical direction, so that its operation is stable. can do.

Furthermore, by installing the PCV valve so that it passes through the extension part of the hot water riser up and down,
When connecting the PCV valve to the crankcase, the blow-by gas conduit can be short. In addition, it becomes possible to connect the PCV valve and the blow-by gas inlet of the intake manifold with an inverted U-shaped pipe.
This also prevents moisture from accumulating during this time. Therefore, freezing of the blow-by gas passage can also be prevented.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway schematic side view showing an embodiment of an engine equipped with a blow-by gas reduction device according to the present invention, FIG. 2 is a plan view of the intake manifold of the engine, and FIG. FIG. 4, a rear view of the intake manifold, is a cutaway side view of the main part of the intake manifold. 1...Engine body, 1a...Combustion chamber, 1b...
... Crank case, 3 ... Carburetor, 4 ... Intake manifold, 5 ... Hot water riser, 5a, 5b ... Extension part, 7 ... Ventilation valve (PCV valve), 7a ... Valve body, 7b ... Valve spring, 8 ... Blowby gas conduit, 9 ... Inverted U-shaped pipe, 14 ... Blowby gas introduction passage, 15 ...
Blow-by gas inlet, 16...Hot water inlet, 1
7...Hot water outlet.

Claims (1)

[Claims for Utility Model Registration] A ventilator is provided by extending the hot water riser 5 provided on the intake manifold 4, and having a valve body 7a pressed downwardly in the closing direction by a valve spring 7b. The intake valve 7 is installed vertically from the lower surface side of the intake manifold 4 through the extension portion 5a of the warm water riser and exposed to the upper surface side of the intake manifold, and the blow-by gas in the crankcase 1b is removed. A blow-by gas conduit 8 is connected to the lower end of the ventilation valve 7, and the upper end of the ventilation valve 7 is connected to the blow-by gas introduced into the intake manifold 4 through an inverted U-shaped pipe 9. A blow-by gas reduction device in an engine connected to port 15.