JP2009097386A - Blow-by gas recirculation device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the inspection work of a PCV valve in a blow-by gas recirculation device for an internal combustion engine. <P>SOLUTION: The blow-by gas recirculation device 3 includes a head cover 2, the PCV valve 4, and a valve cover 5. The PCV valve 4 includes a suction port 44 and a discharge port 45, and is installed on the head cover 2 in such a manner that the suction port 44 is connected to a second passage 22. The valve cover 5 is a member which is installed in an outer part of the head cover 2 to cover the PCV valve 4 and a hole 25. The valve cover 5 forms a third passage 27 connecting a hole 25 and the discharge port 45 of the PCV valve 4, and includes a pressure variable mechanism 52 capable of changing pressure in the third passage 27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a blow-by gas recirculation device for an internal combustion engine.

A conventional internal combustion engine is provided with a blow-by gas recirculation device that guides the blow-by gas in the crank chamber to the intake passage. This blow-by gas recirculation device has a recirculation passage connecting the crank chamber and an intake passage, and a PCV (Positive Crankcase Ventilation) valve provided in the recirculation passage (see, for example, Patent Document 1). The flow rate of blow-by gas is adjusted by the PCV valve.
JP-A-11-117722

The valve body of the PCV valve may stick due to moisture or oil contained in the blow-by gas. For this reason, it is necessary to periodically check the PCV valve.
However, in the blow-by gas recirculation device described in Patent Document 1, the lid member is fixed to the intake manifold by bolts. For this reason, when inspecting the PCV valve, it is necessary to remove these bolts and the lid member and further remove the PCV valve.
Thus, in the conventional blow-by gas recirculation device, the inspection work of the PCV valve becomes complicated.
An object of the present invention is to simplify the inspection work of a PCV valve in a blow-by gas recirculation device for an internal combustion engine.

The blow-by gas recirculation device for an internal combustion engine according to the present invention includes a head cover, a PCV valve, and a cover member. The head cover has a hole included in the return passage that connects the crank chamber of the internal combustion engine and the intake passage. The PCV valve is provided in the reflux passage and is attached to the head cover. The cover member is a member attached to the outside of the head cover so as to cover the PCV valve and the hole. The cover member is formed in an intermediate passage that is included in the reflux passage and connects the discharge port of the PCV valve and the hole together with the head cover, and has a pressure variable mechanism that can change the pressure of the intermediate passage.
In this blow-by gas recirculation device, the pressure in the intermediate passage formed on the discharge port side of the PCV valve can be changed by the pressure variable mechanism. In the PCV valve, the valve body moves inside the casing in accordance with the pressure difference between the suction port side and the discharge port side, and adjusts the flow rate of blow-by gas. For example, when the pressure in the intermediate passage is changed so that this pressure difference becomes small, the PCV valve is closed. At this time, when the valve body is not fixed, the valve body collides with the casing, and a collision sound is generated in the PCV valve. When the valve body is fixed, this collision noise is not generated even if the pressure of the intermediate passage is changed by the pressure variable mechanism.

  Thus, in this blow-by gas recirculation device, since the cover member has the variable pressure mechanism, the operation of the PCV valve can be confirmed without removing the cover member, and the inspection work of the PCV valve can be simplified. It becomes possible.

  In the blow-by gas recirculation device for an internal combustion engine according to the present invention, since the cover member has a pressure variable mechanism, the inspection work of the PCV valve can be simplified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
<Overall configuration of internal combustion engine>
An internal combustion engine 1 employing a blowby gas recirculation device 3 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a schematic configuration diagram of the internal combustion engine 1.
As shown in FIG. 1, the internal combustion engine 1 mainly includes a cylinder block 11, a cylinder head 20, a head cover 2, and a crankcase 12. The cylinder block 11 and the crankcase 12 form a crank chamber 10 in which the crankshaft 17 is disposed.
The cylinder block 11 has a plurality of cylinders 13. A piston 14 is movably disposed in the cylinder 13. The cylinder head 20 is provided on the upper part of the cylinder block 11. A combustion chamber 15 is formed by the cylinder head 20, the cylinder 13 and the piston 14. An intake passage 18 and an exhaust passage 19 are connected to the combustion chamber 15. The piston 14 is connected to the crankshaft 17 via a connecting rod 16. A head cover 2 is attached to the upper part of the cylinder head 20.

<Overall configuration of blow-by gas recirculation device>
As shown in FIG. 1, the blow-by gas recirculation device 3 that guides the blow-by gas in the crank chamber 10 to the intake passage 18 is incorporated in the internal combustion engine 1. Here, the whole structure of the blowby gas recirculation apparatus 3 is demonstrated using FIGS. FIG. 2 is an exploded perspective view of the valve cover 5 and the head cover 2. FIG. 3 is a plan view of the valve cover 5. 4 and 5 are VV cross-sectional views of FIG. In addition, in FIG. 1, the main structures of the blowby gas recirculation apparatus 3 are shown, and the other structure is abbreviate | omitted.
As shown in FIG. 1, the blow-by gas recirculation device 3 mainly includes a recirculation passage P that connects the crank chamber 10 and the intake passage 18, a PCV valve 4 that is provided in the recirculation passage P and adjusts the flow rate of blow-by gas, It is composed of The recirculation passage P includes a first recirculation passage P1 that connects the suction port 44 of the PCV valve 4 and the crank chamber 10, and a second recirculation passage P2 that connects the discharge port 45 of the PCV valve 4 and the intake passage 18. Have.

(1) First return passage As shown in FIG. 1, the first return passage P <b> 1 includes a first passage 31 provided in the cylinder block 11 and a second passage 22 provided in the head cover 2. Yes. The first passage 31 connects the crank chamber 10 and the second passage 22. The second passage 22 has an oil separator 23 and is connected to the suction port 44 of the PCV valve 4.
(2) PCV Valve As shown in FIG. 4, the PCV valve 4 is attached to the head cover 2 via a grommet 46 and is covered with a valve cover 5 as a cover member. The PCV valve 4 includes a substantially cylindrical casing 41, a valve body 42 that is movably disposed in the casing 41, and a spring 43. Since the spring 43 is disposed between the casing 41 and the valve body 42 in a pre-compressed state, the valve body 42 is pressed against the casing 41 by the spring 43.

The casing 41 has a suction port 44 and a discharge port 45. When the PCV valve 4 is closed, the suction port 44 is sealed by the valve body 42. When the pressure on the discharge port 45 side becomes lower than the pressure on the suction port 44 side, the valve body 42 moves to the discharge port 45 side due to the pressure difference, and the PCV valve 4 is opened. In this case, blow-by gas flows from the suction port 44 to the discharge port 45 through a gap formed between the casing 41 and the valve body 42. Thus, the PCV valve 4 has a function of adjusting the flow rate of blow-by gas in accordance with the pressure difference. The suction port 44 is connected to the first return passage P1, and the discharge port 45 is connected to the second return passage P2.
(3) Second return passage As shown in FIG. 1, the second return passage P2 is provided in the head cover 2 and the third passage 27 (intermediate passage) formed between the valve cover 5 and the head cover 2. A fourth passage 26 and a fifth passage 32 provided in the cylinder block 11 are provided. A hole 25 included in the fourth passage 26 is formed in the head cover 2. The hole 25 and the PCV valve 4 are covered with a valve cover 5. The discharge port 45 and the hole 25 of the PCV valve 4 are connected by a third passage 27. The third passage 27 is connected to the intake passage 18 via the fourth passage 26 and the fifth passage 32.

With the above configuration, blow-by gas is guided to the intake passage 18 via the first return passage P1, the PCV valve 4, and the second return passage P2.
<Configuration of valve cover>
(1) Outline of Valve Cover As described above, the blow-by gas recirculation device 3 has the valve cover 5 attached to the head cover 2.
Specifically, as shown in FIGS. 2 to 4, the valve cover 5 is made of, for example, aluminum or a resin having a relatively high heat insulating property, and the head cover is covered with two bolts 59 so as to cover the PCV valve 4 and the hole 25. 2 is fixed to the outer wall surface 29. The head cover 2 is formed with a recess 24 that is recessed inward from the outer wall surface 29. The PCV valve 4 is disposed in the recess 24. Most of the PCV valve 4 is accommodated in the recess 24. A hole 25 included in the fourth passage 26 is formed in the recess 24. The valve cover 5 is attached to the head cover 2 so as to cover the recess 24. A third passage 27 is formed by the recess 24 and the valve cover 5.

The valve cover 5 has a function of changing the pressure in the third passage 27 (the discharge port 45 side of the PCV valve 4). Specifically, as shown in FIGS. 2 to 4, the valve cover 5 includes a cover main body 51 and a pressure variable mechanism 52 provided on the cover main body 51.
(2) Cover body The cover body 51 has a cover part 51a and a flange 51b. The cover part 51 a is a part that accommodates a part of the PCV valve 4. The flange 51 b is a portion that is fixed to the head cover 2 by a bolt 59 and is in contact with the outer wall surface 29. A pressure variable mechanism 52 is provided on the side of the cover portion 51a.
(3) Pressure variable mechanism The pressure variable mechanism 52 includes a cylindrical portion 53 as an opening projecting from the cover portion 51 a and a lid 54 as a lid member attached to the cylindrical portion 53.

The cylindrical portion 53 has a hole 53a. In a state where the lid 54 is not fitted in the cylindrical portion 53, the inner space (third passage 27) and the outer space S of the cover main body 51 are connected by a hole 53a. The cylindrical portion 53 is integrally formed with the cover portion 51a, and is made of the same aluminum or resin as the cover portion 51a.
The lid 54 is fitted into the cylindrical portion 53 so that the air in the space S does not flow into the third passage 27 via the cylindrical portion 53. Specifically, the lid 54 includes a cylindrical lid body 54a and a closing portion 54b that closes one end of the lid body 54a. By removing the lid 54 from the cylindrical portion 53 or mounting the lid 54 on the cylindrical portion 53, the opening 53a of the cylindrical portion 53 can be opened and closed. The lid 54 is made of rubber, for example.
For example, the inner diameter of the lid main body 54 a is set slightly smaller than the outer diameter of the cylindrical portion 53 so that outside air does not leak into the third passage 27 from between the lid 54 and the cylindrical portion 53. During operation of the internal combustion engine 1, the intake passage 18 has a negative pressure, so the pressure in the third passage 27 is lower than the pressure in the space S, and the lid 54 is pulled toward the third passage 27. For this reason, the lid 54 does not fall off the cylindrical portion 53 unless an external force is applied.

As shown in FIGS. 3 and 4, the variable pressure mechanism 52 is disposed at a position higher than the hole 25 and the PCV valve 4. More specifically, the center of the cylindrical portion 53 is disposed at a position higher than the center of the hole 25 and the center of the discharge port 45. The hole 25 is disposed at a position lower than the discharge port 45 of the PCV valve 4. More specifically, the center of the hole 25 is disposed at a position lower than the center of the discharge port 45. As shown in FIG. 3, in this embodiment, the hole 25 is disposed on the left side in the horizontal direction with respect to the discharge port 45 of the PCV valve 4.
<Operation of blow-by gas recirculation device>
Operation | movement of the blowby gas recirculation apparatus 3 is demonstrated using FIGS.
As shown in FIG. 4, the third passage 27 that is the space around the discharge port 45 of the PCV valve 4 is connected to the intake passage 18. For this reason, during operation of the internal combustion engine 1, the pressure in the third passage 27 is lower than the pressure in the second passage 22, and a pressure difference occurs between the suction port 44 side and the discharge port 45 side of the PCV valve 4. As a result, the valve element 42 moves toward the discharge port 45 against the spring force of the spring 43, and blow-by gas flows into the third passage 27 through the gap between the casing 41 and the valve element 42.

Thus, the PCV valve 4 is automatically opened in accordance with the pressure difference, and the blow-by gas in the crank chamber 10 enters the intake passage 18 through the first recirculation passage P1, the PCV valve 4 and the second recirculation passage P2. Led. Thereby, the unburned part of blow-by gas can be burned in the combustion chamber 15.
<PCV valve inspection work>
Since the blow-by gas contains an oil component, the PCV valve 4 may be fixed due to the oil component. For this reason, it is necessary to periodically check whether the valve body 42 of the PCV valve 4 operates normally.
Therefore, in this blow-by gas recirculation device 3, a variable pressure mechanism 52 is provided in the valve cover 5. The operation of the PCV valve 4 can be easily confirmed by the pressure variable mechanism 52.

For example, as shown in FIG. 5, when the lid 54 of the pressure variable mechanism 52 is removed from the cylindrical portion 53 during the operation of the internal combustion engine 1, the air outside the valve cover 5 (space S) passes through the hole 53 a of the cylindrical portion 53. It flows into the third passage 27. As a result, the pressure in the third passage 27 (around the discharge port 45 of the PCV valve 4) increases, and the pressure difference between the suction port 44 side and the discharge port 45 side decreases. For this reason, if the valve body 42 is not firmly fixed in the casing 41, the valve body 42 returns to the position (closed position) shown in FIG. At this time, since the valve body 42 collides with the casing 41, a collision sound of the valve body 42 is generated. If the valve body 42 is fixed in the casing 41, the collision sound of the valve body 42 cannot be heard.
When the lid 54 is attached to the cylindrical portion 53, the pressure of the third passage 27 becomes lower than the pressure of the second passage 22, and the valve body 42 moves to the discharge port 45 side according to this pressure difference. Thereby, the valve body 42 moves to the position (open position) shown in FIG. 4, and blow-by gas flows into the intake passage 18 via the first recirculation passage P1, the PCV valve 4 and the second recirculation passage P2.

As described above, in this blow-by gas recirculation device 3, by simply removing the lid 54 from the cylindrical portion 53, it is confirmed whether or not the valve body 42 of the PCV valve 4 is fixed based on the collision sound of the valve body 42. Can do.
<Features>
The features of the blow-by gas recirculation device 3 are as follows.
(1)
In this blow-by gas recirculation device 3, the pressure variable mechanism 52 can change the pressure on the discharge port 45 side (third passage 27) of the PCV valve 4. Specifically, by removing the lid 54 from the cylindrical portion 53, the pressure in the third passage 27 (on the discharge port 45 side of the PCV valve 4) is made substantially the same as the pressure outside the valve cover 5 (space S). The pressure difference between the suction port 44 side and the discharge port 45 side is reduced. As a result, when the valve body 42 is not fixed in the casing 41, the valve body 42 of the PCV valve 4 moves to the suction port 44 side by the spring force of the spring 43, and the valve body 42 collides with the casing 41. By confirming the collision sound of the valve body 42, it can be confirmed whether or not the valve body 42 is fixed.

Thus, in this blow-by gas recirculation device 3, the pressure on the outlet 45 side of the PCV valve 4 can be changed simply by removing the lid 54, and the operation of the PCV valve 4 is confirmed based on the collision sound. Can do. As a result, the operation of the PCV valve 4 can be checked without removing the valve cover 5, and the inspection work of the PCV valve 4 can be simplified.
(2)
In this blow-by gas recirculation device 3, since the cylindrical portion 53 is provided at a position higher than the hole 25, even if water or oil separated from the blow-by gas accumulates in the valve cover 5, the cylindrical portion 53 passes through the hole 53 a of the cylindrical portion 53. Prevents leakage of moisture and oil.
(3)
In this blow-by gas recirculation device 3, since the PCV valve 4 is provided in the recess 24 of the head cover 2, the PCV valve 4 can be prevented from projecting greatly outside the head cover 2, and the internal combustion engine 1 can be downsized. Become.

(4)
When the moisture in the blow-by gas is discharged from the PCV valve 4 to the valve cover 5 side, the moisture accumulates in the valve cover 5 and may be cooled by outside air and freeze.
In this blow-by gas recirculation device 3, since the hole 25 is disposed at a position lower than the discharge port 45 of the PCV valve 4, it is possible to prevent the discharge port 45 of the PCV valve 4 from being blocked due to water icing.
(5)
In this blow-by gas recirculation device 3, since the third passage 27 is formed by the valve cover 5 and the head cover 2, compared to the case where the outlet 45 and the hole 25 of the PCV valve 4 are connected by a hose or the like, The third passage 27 is easily warmed by the heat transmitted from the cylinder block 11 and the head cover 2. Thereby, it is possible to prevent the moisture in the blow-by gas from freezing in the third passage 27 and to stabilize the operation of the blow-by gas recirculation device 3.

Further, since the valve cover 5 is used instead of the hose, it is possible to prevent the hose from protruding greatly from the outer wall surface 29 of the head cover 2. That is, in this blow-by gas recirculation device 3, the internal combustion engine 1 can be downsized.
[Second Embodiment]
Here, components having substantially the same functions as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
<Composition of cover>
In the first embodiment described above, the valve cover 5 is provided with the cylindrical portion 53 and the lid 54, but the valve cover 105 shown in FIGS. 6 to 8 is also conceivable.
As shown in FIG. 6, the valve cover 105 includes a cover main body 151 and a pressure variable mechanism 152 provided on the cover main body 151. The cover main body 151 has a fixed portion 151b and a substantially cylindrical side wall portion 151a extending from the fixed portion 151b. The fixing portion 151 b is a portion that is fixed to the head cover 2.

The pressure variable mechanism 152 includes a cover plate 153 fixed to the cover main body 151 (more specifically, the side wall portion 151a). An annular protrusion 151c extending toward the inner periphery is formed at the end of the side wall 151a. The cover plate 153 has an annular fixed portion 154 fitted into the protruding portion 151c, and a plate-shaped deformable portion 155 formed inside the fixed portion 154.
The cover plate 153 is made of a softer material (for example, rubber) than the cover main body 151. The deforming portion 155 is disposed so as to face the discharge port 45 of the PCV valve 4, and a gap is secured between the deforming portion 155 and the discharge port 45. The deforming portion 155 can be elastically deformed toward the third passage 27 so as to come into contact with the discharge port 45 of the PCV valve 4. For this reason, as shown in FIG. 9, by applying an external force to the deformation portion 155, the discharge port 45 of the PCV valve 4 can be blocked by the deformation portion 155. That is, the pressure on the discharge port 45 side of the PCV valve 4 can be changed simply by pressing the deforming portion 155 from the outside.

<PCV valve inspection work>
When the internal combustion engine 1 is in operation, when the deformed portion 155 of the cover plate 153 is pushed toward the PCV valve 4 as shown in FIG. 9, the deformed portion 155 is elastically deformed, and the discharge port 45 of the PCV valve 4 is closed. The As a result, the connection between the discharge port 45 of the PCV valve 4 and the third passage 27 is cut off, and the pressure difference between the suction port 44 side and the discharge port 45 side is reduced. As a result, when the valve body 42 is not fixed in the casing 41, the valve body 42 of the PCV valve 4 returns to the closed state, and the valve body 42 collides with the casing 41. At this time, a collision sound of the valve body 42 is generated in the PCV valve 4.
Thus, in this valve cover 105, the operation of the PCV valve 4 can be confirmed based on the collision sound of the valve body 42 only by pressing the deforming portion 155 from the outside, and the inspection work of the PCV valve 4 is simplified. Is possible.

[Other Embodiments]
The specific configuration of the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the invention. In addition, about the structure which has the substantially same function as above-mentioned embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.
(A)
In the first embodiment described above, the pressure variable mechanism 52 includes the cylindrical portion 53 and the lid 54, but the configuration of the pressure variable mechanism 52 is not limited thereto. For example, the valve cover 205 shown in FIG. 10 may be used.
The valve cover 205 includes a cover body 251 and a pressure variable mechanism 252. The cover body 251 has substantially the same shape as the cover body 51 described above. The pressure variable mechanism 252 has a hole 253 formed in the cover main body 251 and a lid 254 fitted in the hole 253. The lid 254 is made of rubber, for example, and is formed at the intermediate portion 254b inserted into the hole 253, the first head 254a formed at the first end of the intermediate portion 254b, and the second end of the intermediate portion 254b. Second head 254c. The outer diameters of the first head 254a and the second head 254c are set to be slightly larger than the inner diameter of the hole 253. Therefore, the lid 254 can be easily removed and attached to the hole 253 while the hole 253 is reliably closed by the lid 254.

Even in this case, the hole 253 can be opened and closed simply by removing the lid 254 from the hole 253 as in the first embodiment, and the inspection work of the PCV valve 4 can be simplified. .
(B)
The shape of the valve cover is not limited to the above-described embodiment. For example, a valve cover 305 shown in FIG. 11 can be considered as a modification of the first embodiment. The valve cover 305 has a cover body 351 having a plate shape. The cover main body 351 is provided with a variable pressure mechanism 52 as in the first embodiment. In this case, the recess 324 is formed deeper than the aforementioned recess 24, and the PCV valve 4 is accommodated inside the outer wall surface 29 by the recess 324.
As in the case of FIG. 11, a valve cover 405 shown in FIG. 12 can be considered as a modification of the second embodiment. The valve cover 405 has a fixed portion 454 and a deformable portion 455. The deformation portion 455 corresponds to the above-described deformation portion 155, and can be elastically deformed toward the discharge port 45 side.

Furthermore, a valve cover 505 shown in FIG. 13 is also conceivable. The valve cover 505 employs the same configuration as the pressure variable mechanism 252 shown in FIG. 10 in the modification shown in FIG. Specifically, the valve cover 505 includes a cover main body 551 and a pressure variable mechanism 552 provided on the cover main body 551. The cover main body 551 has an annular fixing portion 551b and a plate portion 551a. A hole 553 is formed in the plate portion 551a. A lid 554 is attached to the hole 553.
In any case, the configuration of the valve cover can be simplified while enabling the inspection of the PCV valve 4 to be simplified.
(C)
The shape of the head cover is not limited to the above embodiment. For example, a head cover 602 shown in FIG. 14 can be considered as a modification of the first embodiment. The head cover 602 does not have the above-described recess 24, and the PCV valve 4 protrudes from the outer wall surface 629. A hole 25 is formed in the outer wall surface 629.

Similarly to the modification shown in FIG. 14, the case may be considered that the valve cover 105 shown in FIG. 8 is attached to the head cover 602 (see FIG. 15). Furthermore, the case where the valve cover 205 shown in FIG. 10 is attached to the head cover 602 is also conceivable (see FIG. 16).
In either case, the configuration of the head cover can be simplified while enabling the inspection of the PCV valve 4 to be simplified.

  In the blow-by gas recirculation apparatus according to the present invention, the inspection work of the PCV valve can be simplified, and the present invention is useful in the field of internal combustion engines.

Schematic configuration diagram of internal combustion engine (first embodiment) Head cover and exploded perspective view of the cover (first embodiment) Plan view of the cover (first embodiment) PCV valve and its schematic cross-sectional view (first embodiment) PCV valve and its schematic cross-sectional view (first embodiment) Head cover and exploded perspective view of the cover (second embodiment) Plan view of the cover (second embodiment) PCV valve and its schematic sectional view (second embodiment) PCV valve and its schematic sectional view (second embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment) PCV valve and its schematic cross-sectional view (another embodiment)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 10 Crank chamber 11 Cylinder block 12 Crankcase 18 Crank case 18 Intake passage 19 Exhaust passage 2 Head cover 24 Recess 25 Hole 3 Blow-by gas recirculation device 4 PCV valve 41 Casing 42 Valve body 43 Spring 44 Inlet port 45 Outlet port 5 Valve cover (cover) Element)
51 Cover body 52 Variable pressure mechanism 53 Cylindrical part (opening part)
53a hole 54 lid (lid member)
105 Valve cover (cover member)
155 Deformation part P Return passage P1 First return passage 31 First passage 22 Second passage P2 Second return passage 27 Third passage (intermediate passage)
26 4th passage 32 5th passage

Claims (6)

A head cover having a hole included in a reflux passage connecting the crank chamber of the internal combustion engine and the intake passage;
A PCV valve provided in the reflux passage and attached to the head cover;
A member attached to the outside of the head cover so as to cover the PCV valve and the hole, and an intermediate passage included in the reflux passage and connecting the discharge port of the PCV valve and the hole is formed together with the head cover; A cover member having a pressure variable mechanism capable of changing the pressure of the intermediate passage;
An internal combustion engine blow-by gas recirculation device. The cover member has a cover main body that covers the PCV valve and the hole, and the pressure variable mechanism provided in the cover main body.
The pressure variable mechanism includes an opening provided in the cover body and connecting the intermediate passage and a space outside the cover member, and a lid member provided so that the opening can be opened and closed. ing,
The blow-by gas recirculation device for an internal combustion engine according to claim 1. The opening is provided at a position higher than the hole.
The blow-by gas recirculation device for an internal combustion engine according to claim 2. The cover member is at least a part of the pressure variable mechanism and is disposed so as to face the discharge port of the PCV valve via a gap, and is deformed to the discharge port side so as to contact the discharge port of the PCV valve. Have possible deformations,
The blow-by gas recirculation device for an internal combustion engine according to claim 1. The head cover has a recess recessed from the outer wall surface,
The PCV valve is provided in the recess,
The blow-by gas recirculation device for an internal combustion engine according to any one of claims 1 to 4. The hole is provided at a position lower than the discharge port of the PCV valve,
A blow-by gas recirculation device for an internal combustion engine according to any one of claims 1 to 5.

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