JPS6318749Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a filter device for introducing fresh air in a blow-by gas reduction device for an engine.

The so-called blow-by gas that leaks into the crankcase from between the piston and the cylinder wall contains a large amount of unburned gas, oil mist, etc., so it is returned to the intake system using negative intake pressure and combusted within the cylinder. The device for this purpose is known as a blow-by gas reduction device.

This type of blowby gas return device communicates the inside of the crankcase with the inside of the cylinder head cover, communicates the crankcase side with the intake manifold, and sucks the blowby gas with negative pressure inside the intake manifold. A so-called closed type system is often used in which fresh air is returned to the intake system and fresh air is introduced into the crankcase through a filter element provided separately from the air cleaner element, thereby ventilating the inside of the crankcase.

By the way, when the engine is operated at high revolutions and the amount of blow-by gas leaking into the crankcase increases, and the suction action of the negative pressure in the intake manifold can no longer handle it, the blow-by gas is sent to the filter element. There are things to do,
Therefore, oil mist contained in the blow-by gas may adhere to the filter element and cause clogging.

In addition, since the filter element that controls the amount of fresh air introduced is generally placed on the dirty side of the air cleaner case where outside air is introduced, there is a risk of foreign matter such as dust clogging when fresh air is introduced through the filter element. There is a risk that this may occur.

If the filter element becomes clogged in this way, ventilation control of the internal pressure of the crankcase will not be performed smoothly, so countermeasures are desired.

The present invention was developed in response to the above requirements, and its purpose is to ensure that fresh air can be introduced even if the filter element for introducing fresh air into the crankcase becomes clogged. In addition to making it possible to control the ventilation of the internal pressure of the crankcase, it also has a fresh air purification effect that approximates the performance of a filter, and is ideal for introducing fresh air into the blow-by gas reduction system of an engine that is designed to be more compact. To provide filter equipment.

In order to achieve such an objective, the present invention forms a space in the filter case on the back side of the filter element housed in the filter case, forms a labyrinth in the space, and further includes a space at one end of the labyrinth-like space. The gist is that the fresh air intake side on the surface side of the filter element is communicated with the fresh air intake side through a passage, and a fresh air intake port connected to the crankcase side is provided at the other end of the labyrinth-like space.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a longitudinal side view showing an example of a blow-by gas reduction device including an engine, and FIG. 2 is a longitudinal side view of an air cleaner.

The engine 1 consists of a crankcase 2, a cylinder block 3, a cylinder head 4, and a cylinder head cover 5.
A piston 7, which is slidably fitted therein, is connected to the cylinder head 4 by a connecting rod 8, and a combustion chamber 10 is formed in the cylinder head 4 on the upper surface side of the piston 7. The combustion chamber 10 includes an intake port 11 and an intake manifold 1
2. It communicates with the clean side 22 of the air cleaner 20 via the throttle body 13 and conduit 14, as well as with the exhaust port 16 and the exhaust manifold 17.

The inside of the crankcase 2 and the inside of the cylinder head cover 5 are communicated with each other via a communication passage 9 formed through the cylinder block 3 and the cylinder head 4, and one side of the crankcase 2 is connected to the inside of the case 2. A breather chamber 25 is attached, in which a maze 26 is formed, and this breather chamber 25 has a PCV valve (PosiveCrankcaseVentilationValve) 27.
and communicates with the intake manifold 12 via a conduit 28. Here, the PCV valve 27 is a type of flow control valve, and its flow characteristics are set such that the larger the differential pressure, the smaller the flow rate.

On the other hand, a maze-like chamber 31 is formed above the cam chamber 30 in the cylinder head cover 5 and communicates with the cam chamber 30.
It communicates with the dirty side 23 of the air cleaner 20 via the filter case 40 and the filter case 40 .

An annular air cleaner element 21 is housed inside the air cleaner 20. The inside of the air cleaner element 21 constitutes a clean side 22, and the outside constitutes a dirty side 23 communicating with an outside air intake pipe 24. A filter device according to the invention is attached to a part of the side wall of side 23.

The structure of the filter device is as shown in FIG. 4--FIG. 3 showing a vertical side view and FIG.
It is formed into a box shape with an opening 41 on one side of the rectangular part, and the interior is divided into a large space S ₁ and a small space S ₂ by a partition plate 42 formed near one end of the interior. Vertical slits 43, 43 are formed on the left and right sides of this partition plate 42, respectively.

In the large space _S1 of the filter case 40,
Two cylindrical mounting brackets 45, 45 in the longitudinal direction extending from the bottom wall 44 face up to the opening 41, and screw holes 46, 46 are provided in the mounting brackets 45, 45.
are formed, and the lower part between these mounting brackets 45, 45 is continuous with a protrusion 52 extending from the bottom wall 44 in the longitudinal direction, and as if the protrusion 52 is extended, each mounting bracket 45, Projecting pieces 53 and 54 are also provided at the outer ends of the bottom wall 44 in the longitudinal direction, respectively, and the tips of these projecting pieces 53 and 54 are as follows.
Partition plate 42 and rear wall 47 of filter case 40, respectively.
The space is created in a difficult manner.

Projections 55, 55 and 56, 56 extending in the left-right direction are respectively provided upright from the bottom wall 44 at the front and back of the projection 52 that extends between the lower portions of both mounting brackets 45, 45. The tips of the pieces 55, 55 and 56, 56 are spaced apart from the left and right walls 48, 49 of the filter case 40, respectively.

On the other hand, protrusions 57 and 57 are also provided inwardly at the longitudinally intermediate portions of the left and right walls 48 and 49 of the filter case 40, respectively.
are formed continuously with the bottom wall 44, and these projecting pieces 5
The tips of 7 and 57 are attached to both mounting brackets 45 and 45.
The protruding piece 52 is continuous between the lower parts of the partition plate 42 of the left and right walls 48, 49 to form a space.
Similarly, protrusions 58, 58 are formed inwardly at the closer portions, respectively. Further, protrusions 59, 59 are formed on the left and right sides of the rear wall 47 and extend inward.

Each of the protrusions described above is formed at the same height, and thus a labyrinth 51 is formed at the bottom of the large space _S1 of the filter case 40 in the longitudinal direction.

The lower or bottom wall 4 of the rear wall 47 of the filter case 40 faces the partition plate 42 across the large space _S1 .
A fresh air intake port 61 is formed in the center of the rear part of the air conditioner 4, and a fresh air intake pipe 62 is formed to be continuous with the intake port 61 in an inclined manner.

The filter element 60 is housed in the large space _S1 of the filter case 40 constructed as described above so as to be placed on each protrusion. As a result, a labyrinth-like space 50 is formed on the back side of the filter element 60. Further, a fresh air intake space 65 is formed between the front side of the filter element 60 and the opening 41 of the filter case 40.

The opening 41 of the filter case 40 housing the filter element 60 is thus aligned with the side wall of the dirty side 23 of the air cleaner 20, and the air cleaner 2
Attach the filter case 40 to the air cleaner 20 by tightening the two mounting screws 69, 69 from the inside of the filter case 40 into the screw holes 46, 46 of the mounting brackets 45, 45, respectively. The vent pipe 62 is connected to the pipe line 32 leading to the cylinder head cover 5 in the embodiment.

Note that a rectangular shape 71 indicated by diagonal lines in FIG. 4 represents the opening shape of a fresh air intake port provided on the side wall of the air cleaner 20 for introducing fresh air into the filter case 40.

Next, the operation of such a filter device will be described.

First, while the engine 1 is operating, the breather chamber 25 is in communication with the intake manifold 12, so
Blowby gas leaking into the crankcase 2 from between the piston 7 and the cylinder block 3 is returned to the intake manifold 12 via the breather chamber 25, the PCV valve 27, and the conduit 28 due to the negative pressure within the intake manifold 12.

On the other hand, since the inside of the cylinder head cover 5 is connected to the inside of the crankcase 2 through the communication passage 9, the negative pressure in the cylinder head cover 5 draws the air from the dirty side 23 of the air cleaner 20 into the filter case 40 as shown by the white arrow in FIG. 3, and the fresh air purified by the filter element 60 flows into the labyrinth space 50 and is discharged from the fresh air outlet pipe 6.
Fresh air is introduced from the cylinder head cover 5 through a pipe 32 and a chamber 31 into a cam chamber 30 in the cylinder head cover 5, and this fresh air is further introduced into the crankcase 2 to ventilate the crankcase.

In the above, since the filter case 40 is arranged on the dirty side 23 of the crankcase 20, foreign matter such as dust flows into the fresh air intake space 65 together with the air, and this causes the filter element 60 to
There is a risk of clogging.

Further, when the engine 1 is operated at high speed, that is, under high load, a large amount of blowby gas leaks from the combustion chamber 10, and since the intake negative pressure of the intake manifold 12 is small, little blowby gas is returned to the intake manifold 12. Therefore, the pressure inside the crankcase 2 and the cylinder head cover 5 becomes higher than atmospheric pressure, and the blow-by gas flows into the maze-like space 50 inside the filter case 40 through the chamber 31 and the pipe 32 inside the cylinder head cover 5. There is a possibility that the oil mist contained in the blow-by gas may clog the filter element 60.

If the filter element 60 becomes clogged in this way, first, when introducing fresh air, the outside air containing foreign matter is introduced into the fresh air intake space 65 in the filter case 40 through the left and right slits 4 of the partition plate 42.
It flows into the small space S ₂ at one end from the upper part of the slits 3 and 43, and further flows from the small space S ₂ into the maze-like space 50 through the lower part of the slits 43 and 43. When the outside air flows into the maze-like space 50 inside the filter case 40 through the so-called bypass passage consisting of the slits 43, 43 and the small space _S2 , the slits 43, 43
Since the upper and lower parts of the partition plate 42 are also squeezed, foreign matter adheres to the front and back sides of the partition plate 42, respectively. Furthermore, the outside air flowing into the maze-like space 50 flows between the left and right projections 58 and 58 of the first stage, as shown by the solid line arrows in FIGS. 3 and 4.
Each of the protrusions and Longitudinal projecting pieces 53, 52, 54, and further the rear wall 4
Foreign matter adheres to the protrusions 59, 59, etc. of 7, and only the fresh air that has been purified by removing the foreign matter flows out from the fresh air outlet 61 to the fresh air outlet pipe 62, and thereafter flows through the pipe line 32.
Fresh air is introduced into the cam chamber 30 through the chamber 31, and the desired ventilation inside the crankcase 2 is performed.

As described above, the maze-like space 50 inside the filter case 40 performs a fresh air purification action that approximates the performance of a filter.

Further, when the blow-by gas flows back into the filter case 40, the oil mist is removed through the maze-like space 50 and the bypass passages 43, 43, _S2 , and the air is opened to the atmosphere, contrary to the above.

Therefore, according to the filter device according to the present invention, the internal pressure of the crankcase 2 can be sufficiently controlled for ventilation, and moreover, it can also provide a fresh air purification effect that approximates the performance of a filter.

Furthermore, since it is sufficient to form the labyrinthine space 50 and the bypass passages 43, 43, _S2 within the filter case 40, it is convenient in terms of compactness.

By the way, as a blow-by gas return device, two chambers 35 and 36 are formed in the upper part of the cylinder head cover 5 as shown in FIG. The filter case 40 communicates with the other chamber 36 through a conduit 32.
The filter case 40 may be attached to the dirty side 123 of the air cleaner 120 housing the disk-shaped air cleaner element 121.

Although not shown, there is also a blow-by gas return device that communicates the inside of the cylinder head cover with the inside of the intake manifold via a PCV valve, and communicates the inside of the crankcase with an air cleaner.

FIGS. 6 and 7 show the structure of a filter device having substantially the same construction as that described above, which is employed in such a blow-by gas reduction device.

A box-shaped filter case 140 that is approximately a rectangular parallelepiped and has an opening 141 on one side of the rectangular part.
The interior is divided into a large space S ₁ and a small space S ₂ by a partition plate 142 formed near one end, and vertical slits 143 and 1 are provided on the left and right sides of this partition plate 142, respectively.
43 is formed, and two mounting brackets 145, 145 are installed in the longitudinal direction within the large space _S1 .

and the mounting bracket 145,1 in the large space _S1 .
A protruding piece 152 is continuously formed between the lower part of the protruding piece 152, and protruding pieces 155, 1 are formed in the left and right direction at the front and back of this protruding piece 152, respectively.
55, 156, and 156 are formed.

In addition, protrusions ₁₅₇ , 157, 158,
158 and 159, 159, and the rear wall 147
A fresh air outlet 161 is formed in the lower central part of the air outlet, and a fresh air outlet pipe 162 is formed to be continuous with the outlet 161 at an angle.

The filter element 160 is housed in the large space S ₁ of the filter case 140, thereby forming a labyrinth-like space 150 on the back side of the filter element 160.
A fresh air intake space 165 is formed on the surface side.

Then, align the opening 141 of the filter case 140 with the dirty side of the air cleaner, tighten the two mounting screws to the mounting brackets 145, 145, and attach the filter case 140 to the air cleaner.
A fresh air take-off pipe 162 is connected to the crankcase via a conduit.

In FIG. 7, which is a plan view, the circular shapes 171, 171 indicated by diagonal lines are the opening shapes of fresh air intake ports provided in the side wall of the air cleaner for introducing fresh air into the filter case 140.

The fresh air introduced into the filter case 140 is purified by the filter element 160 and sucked into the crankcase, as shown by the blank arrow in FIG. If the element 160 becomes clogged, the slits 143, 1 of the partition plate 142
Outside air flows into the maze-like space 150 through a bypass passage consisting of a small space S ₂ and a small space S 2 . As shown by solid line arrows in FIGS. 6 and 7, between the protrusions 158 and 158 of the first stage, and between the protrusions 156 and 156 of the second stage.
between the protruding pieces 157, 157 of the third stage, the outer side of the protruding pieces 155, 155 of the fourth stage, and the protruding piece 1 of the final stage.
59 and 159, only fresh air that has been purified by removing foreign matter flows out from the fresh air outlet 161 to the fresh air outlet pipe 162, thereby ventilating the inside of the crankcase.

Also, when blow-by gas flows backward from inside the crankcase, the air is released to the atmosphere in the reverse order.

In each of the embodiments, slits are formed vertically in the partition plate, but instead of slits, small holes may be formed at the top and bottom of the partition plate.

As is clear from the above description, according to the filter device of the present invention, a space is formed on the back side of the filter element housed inside, a labyrinth is formed in the space, and one end of the labyrinth-like space is formed. and the fresh air intake side on the surface side of the filter element are communicated through a so-called bypass passage, and a fresh air intake port connected to the engine case side is provided at the other end of the labyrinth-like space to configure the filter device. Even if the filter element becomes clogged, fresh air can be smoothly introduced into the crankcase side, and sufficient ventilation control of the crankcase internal pressure can be performed, and the performance approximates that of the filter. It has many advantages, such as being able to have a good fresh air purification effect and requiring only a simple and compact structure.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a longitudinal side view showing an example of a blow-by gas reduction device including an engine, Fig. 2 is a longitudinal side view showing an example of an air cleaner, and Fig. 3 is a longitudinal side view showing an example of an air cleaner. FIG. 4 is a plan view of the filter device according to the first embodiment, FIG. 5 is a longitudinal side view showing another embodiment of the blow-by gas reduction device, and FIG. 6 is a second embodiment of the present invention. FIG. 7 is a longitudinal sectional side view of the filter device according to the example, and FIG. 7 is a plan view thereof. In the drawing, 1 is the engine, 2 is the crankcase,
12 is an intake system, 20 is an air cleaner, 21 is its element, 40 is a filter case, 50 is its space, 51 is a labyrinth, 43, 43 and S ₂ are passages, 6
0 is the filter element, 61 is the fresh air intake port, 6
5 is the new intake side.

Claims (1)

[Scope of utility model registration request] In a blow-by gas return device that introduces fresh air into the crankcase side through a filter element provided separately from the air cleaner element and returns blow-by gas from the crankcase side to the engine intake system, a filter housing the above-mentioned filter element is used. A space is formed on the back side of the filter element in the case, a passage communicating between one end of the space and the fresh air intake side on the front side of the filter element is formed, and the crank is connected to the other end of the space. A filter device for introducing fresh air in a blow-by gas reduction device for an engine, characterized in that a fresh air intake port connected to a case side is formed, and a labyrinth is further formed in the space.