JP4910973B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine having a circulation passage for reintroducing blow-by gas into a combustion chamber.

When combustion of the mixed gas occurs in the combustion chamber of the internal combustion engine, the pressure of the gas in the combustion chamber becomes extremely high. Accordingly, a part of the gas in the combustion chamber leaks through the gap formed between the wall surface forming the cylinder bore and the piston ring into the crankshaft housing space formed by the cylinder block portion and the crankcase portion (blows through). ). This blown-out gas (blow-by gas) contains harmful components such as hydrocarbon (HC), nitrogen oxide (NOx), and sulfur oxide (SOx) in addition to carbon dioxide (CO ₂ ) and water vapor (H ₂ O). Contains relatively much.

  Therefore, if the blowby gas accumulates in the crankshaft housing space and the pressure in the crankshaft housing space becomes excessively high, harmful components contained in the blowby gas leak from the crankshaft housing space to the outside of the internal combustion engine. There was a risk of getting out.

Therefore, the conventional internal combustion engine includes a circulation passage for reintroducing blow-by gas into the combustion chamber. According to this internal combustion engine, blow-by gas is subjected to combustion in the combustion chamber, then purified by the catalyst disposed in the exhaust passage, and then released to the atmosphere (see, for example, Patent Document 1). ).
JP 2007-100651 A

  Therefore, since the pressure in the crankshaft housing space can be prevented from becoming excessively high, it is possible to prevent the blowby gas from leaking from the crankshaft housing space to the outside of the internal combustion engine. That is, it is possible to prevent harmful components contained in blow-by gas from being released to the atmosphere as they are.

  By the way, the blow-by gas passing through the circulation passage is cooled by the wall surface forming the circulation passage. Thereby, the water vapor | steam contained in blowby gas condenses and water is produced | generated. This water adheres to the wall surface forming the circulation passage. Furthermore, an acidic substance is produced | generated by combining the nitrogen oxide and / or sulfur oxide contained in this water and blow-by gas.

  On the other hand, the blowby gas contains mist-like lubricating oil (engine oil). This lubricating oil produces sludge (sludge-like substance) by combining with the acidic substance produced on the wall surface forming the circulation passage. As a result, there is a problem in that sludge accumulates on the wall surface forming the circulation passage, thereby reducing the cross-sectional area of the circulation passage and obstructing the passage of blow-by gas.

  Therefore, it is considered suitable to dispose a basic substance that neutralizes the acidic substance on the wall surface forming the circulation passage. However, for example, when a sludge suppression layer made of a basic substance is formed on the wall surface forming the circulation passage, there is a problem that if the sludge suppression layer deteriorates, the generation of sludge cannot be suppressed.

  The present invention has been made in order to address the above-described problems, and the object thereof includes a sludge suppression layer without removing the cylinder head portion and the crankcase portion from the cylinder block portion when the sludge suppression layer is deteriorated. An object of the present invention is to provide an internal combustion engine in which members can be exchanged.

In order to achieve such an object, an internal combustion engine according to the present invention provides:
A cylinder bore that is a cylindrical hole penetrating in a predetermined bore central axis direction is formed, and a cylinder block portion that accommodates a piston in the cylinder bore, and the cylinder block portion so as to cover one of the opening portions of the cylinder bore A cylinder head portion that is fixed and includes a head cover, and a crank shaft housing space that is a space for housing a crank shaft connected to the piston and that is connected to the cylinder bore at the other of the opening portions of the cylinder bore. Thus, an engine main body comprising a crankcase fixed to the cylinder block is provided.

  Further, the internal combustion engine according to the present invention forms a mixed gas containing air and fuel in a combustion chamber formed by the wall surface forming the cylinder bore, the cylinder head portion and the piston, and the mixed gas formed in the same manner. An internal combustion engine configured to burn a blow-by gas that is a gas leaked from the combustion chamber into the crankshaft housing space and re-introducing the blow-by gas into the combustion chamber. is there.

In addition, the internal combustion engine according to the present invention is:
It has a sludge suppression layer made of a material that neutralizes acidic substances that promotes sludge generation, and is attached to and detached from the engine body in a state where the cylinder head part and the crankcase part are fixed to the cylinder block part. The sludge suppression member is configured to be configured so that the sludge suppression layer is exposed to the circulation passage when attached to the engine body.
That is, the sludge suppressing member can be said to be a member that defines (forms) a part of the circulation passage.

  According to this, the sludge suppression layer which consists of a substance which neutralizes the acidic substance which accelerates | stimulates the production | generation of sludge is exposed to the circulation path. Thereby, even if an acidic substance is formed on the sludge suppression layer by NOx and / or SOx in the combustion gas, the acidic substance is neutralized by the sludge suppression layer. Thereby, the production | generation of sludge can be suppressed.

  Furthermore, the sludge suppressing member is configured to be detachable from the engine body in a state where the cylinder head portion and the crankcase portion are fixed to the cylinder block portion. Therefore, when the sludge suppression layer deteriorates (that is, when the sludge suppression layer can no longer neutralize the acidic substance), the sludge suppression member is replaced without removing the cylinder head portion and the crankcase portion from the cylinder block portion. can do. That is, the trouble of replacing the sludge suppressing member can be reduced.

In this case, the engine main body has the communication passage formed therein, the communication passage communicating the circulation passage with the outside of the engine main body, and from the outside through the communication hole. The supplied lubricating oil is configured to pass through a part of the circulation passage,
The sludge suppression member is configured to be detachable from the engine main body so as to open and close the communication hole in a state where the sludge suppression member is attached to the engine main body, and the sludge suppression layer is formed at least in part. In addition, it is preferable that the sludge suppression layer is provided with a filler cap configured to be exposed to the circulation passage when attached to the engine main body.

  According to this, it is formed in the filler cap by removing the filler cap provided so that the lubricating oil can be supplied from the outside of the engine main body without removing the sludge suppressing member from the engine main body. A sludge suppression layer can be observed. Thereby, the deterioration state of the sludge suppression layer of a sludge suppression member can be estimated based on the deterioration state of the sludge suppression layer of a filler cap. That is, the deterioration state of the sludge suppressing layer of the sludge suppressing member can be estimated by using the filler cap without providing another part. As a result, the sludge suppressing member can be replaced at an appropriate timing.

In this case, the crankcase part has a lubricating oil storage part for storing lubricating oil,
The sludge suppression member is configured to be detachable from the engine main body while being attached to the engine main body, and when the sludge suppressing member is attached to the engine main body, the tip is stored in the lubricating oil reservoir. The amount of the lubricating oil can be measured by reaching the lubricating oil, and the sludge suppressing layer is formed in the state where the sludge suppressing layer is formed at least partially and attached to the engine body. It is preferable to provide an oil level gauge configured such that the layer is exposed to the circulation passage.

  According to this, by removing the oil level gauge provided in order to be able to measure the amount of stored lubricating oil without removing the sludge suppressing member from the engine main body, the oil level gauge is obtained. The formed sludge suppression layer can be observed. Thereby, the deterioration state of the sludge suppression layer of the sludge suppression member can be estimated based on the deterioration state of the sludge suppression layer of the oil level gauge. That is, the deterioration state of the sludge suppression layer of the sludge suppression member can be estimated by using the oil level gauge without providing another part. As a result, the sludge suppressing member can be replaced at an appropriate timing.

  In this case, it is preferable that the sludge suppressing member is formed integrally with an oil filter that filters the lubricating oil in the engine body.

  According to this, when replacing | exchanging an oil filter, a sludge suppression member can be replaced | exchanged simultaneously. Thereby, compared with the case where a sludge suppression member is replaced | exchanged independently with an oil filter, the effort which replaces | exchanges an oil filter and a sludge suppression member can be reduced.

<First Embodiment>
Embodiments of an internal combustion engine according to the present invention will be described below with reference to the drawings. Hereinafter, the description will be continued using a right-handed orthogonal coordinate system including the X axis, the Y axis, and the Z axis, in which the negative direction of the Z axis coincides with the vertically downward direction (that is, the direction in which gravity acts). .

  The internal combustion engine 10 is an internal combustion engine in which four cylinders are arranged in series in the Y-axis direction. As shown in FIG. 1, the internal combustion engine 10 includes a cylinder block portion 20, a crankcase portion 30, a cylinder head portion 40, an intake system 50, an exhaust system 60, and a circulation passage forming unit 70. ing. Although FIG. 1 shows only a cross section of one cylinder, the other cylinders have the same configuration. Moreover, the cylinder block part 20, the crankcase part 30, and the cylinder head part 40 constitute an engine body part.

<< Cylinder block section >>
The cylinder block 20 is formed with a cylinder bore 21 that is a cylindrical hole penetrating in the Z-axis direction (bore central axis direction). Further, the cylinder block portion 20 includes a piston 22, a connecting rod 23, and a crankshaft 24 as an output shaft.

  The piston 22 is accommodated in the cylinder bore 21. The crankshaft 24 is connected to the piston 22 via a connecting rod 23. The piston 22 reciprocates in the cylinder bore 21, and the reciprocating motion of the piston 22 is transmitted to the crankshaft 24 via the connecting rod 23, whereby the crankshaft 24 is driven to rotate. The crankshaft 24 is disposed on the Z axis negative direction side with respect to the cylinder bore 21. The bore wall surface BS that forms the cylinder bore 21, the top surface (surface on the Z-axis positive direction side) PS of the piston 22, and the lower surface (surface on the Z-axis negative direction side) HS of the cylinder head 40 form the combustion chamber 25. is doing.

  A piston ring PR is disposed in the vicinity of the top surface PS on the side surface of the piston 22. The piston ring PR improves the air tightness of the combustion chamber 25 and scrapes off an excess lubricating oil film formed on the bore wall surface BS forming the cylinder bore 21 in the vertically downward direction.

<< Crankcase part >>
The crankcase portion 30 is fixed to the cylinder block portion 20 at the end of the cylinder block portion 20 on the Z axis negative direction side. The crankcase portion 30, together with the cylinder block portion 20, forms a crankshaft accommodation space SA <b> 1 that is a space that accommodates the crankshaft 24 and that is connected to the cylinder bore 21 at the opening portion of the cylinder bore 21 on the Z axis negative direction side. is doing.

  The crankcase part 30 includes an oil pan 31 as a lubricating oil storage part. Lubricating oil is stored in the oil pan 31. Lubricating oil in the oil pan 31 is sent out to a driving unit of the cylinder block unit 20 and the cylinder head unit 40 by an oil pump (not shown) via a lubricating oil distribution passage (not shown).

<< Cylinder head part >>
The cylinder head portion 40 is fixed to the cylinder block portion 20 so as to cover an opening portion of the cylinder bore 21 on the Z axis positive direction side. The cylinder head portion 40 includes a cylinder head 41 fixed to an end portion on the Z-axis positive direction side of the cylinder block portion 20, and a head cover 42 fixed to an end portion of the cylinder head 41 on the Z-axis positive direction side. . The head cover 42 is fixed to the cylinder head 41 with bolts. A cam housing space SA2 is formed between the cylinder head 41 and the head cover. The cam housing space SA2 constitutes a part of the circulation passage.

The cylinder head 41 is formed with an intake port 41 a that communicates with the combustion chamber 25 and an exhaust port 41 b that communicates with the combustion chamber 25.
The cylinder head 41 further includes an intake valve 41a1 for opening and closing the intake port 41a, an intake valve drive mechanism 41a2 including a cam CI for driving the intake valve 41a1, an exhaust valve 41b1 for opening and closing the exhaust port 41b, and a cam for driving the exhaust valve 41b1. An exhaust valve drive mechanism 41b2 including CE, an ignition plug 41c, an igniter 41d including an ignition coil that generates a high voltage to be applied to the ignition plug 41c, and an injector 41e are provided. The cam CI and the cam CE are accommodated in the cam accommodation space SA2. The injector 41e is configured to inject fuel into the intake port 41a.

  In the head cover 42, as shown in FIG. 3, which is a cross-sectional view of the internal combustion engine 10 taken along a plane including the line 3-3 in FIGS. 2 and 2 and perpendicular to the Y axis, A columnar communication hole 42a is formed to communicate with the outside of the cylinder head portion 40 (engine body portion). The communication hole 42 a is disposed at the end of the head cover 42 on the Y axis negative direction side.

The communication hole 42 a is used when lubricating oil is supplied to the internal combustion engine 10. That is, lubricating oil is supplied from the outside of the internal combustion engine 10 through the communication hole 42a. The supplied lubricating oil passes through the cam housing space SA <b> 2 and flows down in the negative Z-axis direction, and is then stored in the oil pan 31.
Further, a thread is formed on the wall surface forming the communication hole 42a.

  Further, the internal combustion engine 10 includes a filler cap FC. The filler cap FC includes a columnar foot part FCa having the same diameter as the communication hole 42a, and a disk-shaped head part FCb having a larger diameter than the foot part FCa. The foot part FCa and the head part FCb are arranged coaxially.

  On the side surface of the foot portion FCa, a thread groove is formed that is screwed into a thread on the wall surface that forms the communication hole 42a. That is, the filler cap FC opens and closes the communication hole 42a in a state where a first lubricating oil separating cartridge 71 and a second lubricating oil separating cartridge 72 described later are attached to the head cover 42 (engine body). Further, the head cover 42 is configured to be detachable.

  A sludge suppression layer SL made of a substance that neutralizes an acidic substance that promotes the generation of sludge is formed at the tip of the foot part FCa. In this example, the substance which comprises the sludge suppression layer SL is calcium carbonate. The substance constituting the sludge suppression layer SL may be a carboxylate, sulfonate, phenolate or carbonate of an alkaline earth metal such as calcium and magnesium.

  With such a configuration, the sludge suppression layer SL formed at the tip of the foot portion FCa of the filler cap FC has the cam housing space SA2 (circulation passage) in a state where the filler cap FC is attached to the head cover 42 (engine body portion). ) (See FIG. 3).

  FIG. 4 is a cross-sectional view of the internal combustion engine 10 taken along a plane including the line 4-4 of FIG. 2 and perpendicular to the Y axis, and the first lubricating oil separating cartridge 71 and the second lubricating oil. As shown in FIG. 5 showing the head cover 42 with the separation cartridge 72 removed from the head cover 42, the head cover 42 has a first communication hole 42b1 and a second communication hole 42b2. Each of the first communication hole 42b1 and the second communication hole 42b2 opens toward the positive direction of the Z axis. Each of the first communication hole 42b1 and the second communication hole 42b2 is connected to the cam housing space SA2.

  As shown in FIG. 5, each of the first communication hole 42b1 and the second communication hole 42b2 has a substantially rectangular shape having a long side parallel to the Y axis and a short side parallel to the X axis. Is. The first communication hole 42b1 and the second communication hole 42b2 are arranged in parallel with each other at both ends of the head cover 42 in the X-axis direction. The first communication hole 42b1 and the second communication hole 42b2 are disposed on the Y axis positive direction side with respect to the communication hole 42a.

  As shown in FIG. 4, a vertical wall 42c1 extending in the Z-axis positive direction is erected on the surface on the Z-axis positive direction side of the edge of the first communication hole 42b1. The vertical wall portion 42c1 is formed so as to surround the first communication hole 42b1 at a position moved from the edge of the first communication hole 42b1 by the distance L1 toward the outside of the first communication hole 42b1. Has been.

  The vertical wall portion 42c1 is formed with a protruding portion 42c2 that protrudes inward of the first communication hole 42b1. The protrusion 42c2 is disposed at a position away from the surface on the Z-axis positive direction side of the edge by a distance D1 in the Z-axis direction. The length L2 in the protruding direction of the protrusion 42c2 is shorter than the distance L1.

  Similarly to the edge of the first communication hole 42b1, the edge of the second communication hole 42b2 on the Z-axis positive direction side surface of the head cover 42 has the same configuration as the vertical wall 42c1. A wall 42c3 is erected. That is, the protruding portion 42c4 is formed on the vertical wall portion 42c3 in the same manner as the protruding portion 42c2.

  As shown in FIG. 1, the cylinder block portion 20 and the cylinder head portion 40 are formed with an internal passage PT1 that communicates the crankshaft accommodation space SA1 and the cam accommodation space SA2. The internal passage PT1 constitutes a part of the circulation passage.

<< Intake system >>
The intake system 50 supplies air to the engine body. The intake system 50 includes a plurality of independent passages communicating with the intake ports 41a of the respective cylinders, and an intake manifold 51 that forms a collection portion that collects these passages on the upstream side, and an end portion on the collection portion side of the intake manifold 51 A surge tank 52 connected to the suction tank 52, one end connected to the surge tank 52, and an intake duct 53 that forms an intake passage with the intake port 41 a, the intake manifold 51, and the surge tank 52, and the other end of the intake duct 53 downstream (the surge tank 52 ), An air filter 54 and a throttle valve 55 disposed in the intake duct 53 in order.

  The throttle valve 55 is rotatably supported by the intake duct 53. The throttle valve 55 is driven (controlled) by a throttle valve actuator (not shown), thereby adjusting the opening (throttle valve opening TA) to adjust the passage sectional area of the intake duct 53.

<< Exhaust system >>
The exhaust system 60 discharges exhaust gas from the engine body to the outside of the internal combustion engine 10. The exhaust system 60 includes a plurality of independent passages communicating with the exhaust ports 41b of the respective cylinders and an exhaust manifold that forms a collecting portion that collects these passages on the downstream side, and forms an exhaust passage together with the exhaust ports 41b. An exhaust pipe 61 and a three-way catalyst device 62 disposed in the exhaust pipe 61 are provided. The three-way catalyst device 62 purifies harmful components in the exhaust gas such as nitrogen oxide NOx, sulfur oxide SOx, hydrocarbon HC and carbon monoxide CO.

<< Circulation passage formation part >>
The circulation passage forming unit 70 includes a first lubricating oil separating cartridge 71 as a sludge suppressing member, a second lubricating oil separating cartridge 72 as a sludge suppressing member, a first circulating pipe 73, and a second circulating pipe 73. And a circulation pipe 74 of the above.

  As shown in FIGS. 1, 2, and 4, the first lubricant separating cartridge 71 is detachably attached to the head cover 42 at the upper portion of the first communication hole 42b1. The first lubricating oil separating cartridge 71 is a cross-sectional view of the first lubricating oil separating cartridge 71 taken along a plane including the line 6-6 in FIGS. 4 and 2 and perpendicular to the X axis. As shown in FIG. 6, a base portion 71a, a baffle plate 71b, a plurality (two in this example) of lubricating oil separation plates 71c, and a plurality (three in this example) of lubricating oil separation A plate 71d and a seal member 71e are provided.

The base portion 71a is a plate-like member having a predetermined thickness. The base portion 71a has one rectangular top surface TS and four side surfaces SS that are bent from four sides of the top surface TS and extend in the negative Z-axis direction. The ends ES of the four side surfaces SS on the Z axis negative direction side are located in one plane PL1 orthogonal to the Z axis.
That is, the base portion 71a forms a rectangular parallelepiped concave portion SB1 opened at the plane PL1. A sludge suppression layer SL is formed on the surface of the base portion 71a on the concave portion SB1 side.

  The base portion 71a has a shape formed by the side surface SS in a cross section obtained by cutting the base portion 71a in a plane orthogonal to the Z axis, and the shape of the base cover 71a is a plane orthogonal to the Z axis and passes through the protrusion 42c2. It is formed so as to coincide with the shape formed by the tip of the protrusion 42c2 in the cut section. In addition, in the base portion 71a, the wall surface on the recess SB1 side of the portion forming one of the side surfaces SS of the base portion 71a constitutes the same plane as one of the wall surfaces forming the first communication hole 42b1. To be formed.

  Further, each side surface SS is formed with a claw portion 71a1 projecting in a direction (outward) perpendicular to the side surface SS. The claw portion 71a1 is disposed in the vicinity of the end ES of the side surface SS. The length of the claw portion 71a1 in the Z-axis direction is substantially the same as the distance D1. The length in the protruding direction of the claw portion 71a1 monotonously decreases toward the Z-axis negative direction. The maximum length L3 in the protruding direction of the claw portion 71a1 is slightly shorter than the length L2 in the protruding direction of the protruding portion 42c2.

  A communication hole 71a2 that opens in the positive direction of the Z-axis is formed at the end of the base portion 71a where the top surface TS is formed. The communication hole 71a2 is connected to the recess SB1.

  The baffle plate 71b is a flat member. The baffle plate 71b is disposed along a plane orthogonal to the Z axis. The baffle plate 71b is fixed to the surface on the concave portion SB1 side of the portion of the base portion 71a forming the side surface SS so as to form the PCV chamber R1 together with the base portion 71a. The PCV chamber R1 constitutes a part of the circulation passage.

  A sludge suppression layer SL is formed on the surface of the baffle plate 71b on the PCV chamber R1 side. Further, as shown in FIG. 6, the baffle plate 71b is formed with a gas hole 71b1 and a lubricating oil hole 71b2 that connect the upper part of the baffle plate 71b and the lower part of the baffle plate 71b. The gas hole 71b1 is disposed at the end of the baffle plate 71b on the Y axis positive direction side. Further, the lubricating oil hole 71b2 is disposed at the end of the baffle plate 71b on the Y axis negative direction side.

  Each of the lubricant separating plate 71c and the lubricant separating plate 71d is a flat plate-like member. A sludge suppression layer SL is formed on each surface of the lubricating oil separating plate 71c and the lubricating oil separating plate 71d.

  Each lubricating oil separating plate 71c is fixed to the surface on the concave portion SB1 side of the portion of the base portion 71a forming the top surface TS. Each lubricating oil separation plate 71c is arranged along a plane orthogonal to the Y axis. Each of the lubricating oil separating plates 71c is slightly smaller than the position between the baffle plate 71b and the portion closest to the baffle plate 71b on the baffle plate 71b side of the portion of the base portion 71a that forms the top surface TS. It extends to a plane that is located on the Z axis negative direction side and that is orthogonal to the Z axis.

Each lubricating oil separation plate 71d is fixed to a baffle plate 71b. Each of the lubricating oil separating plates 71d is arranged along a plane perpendicular to the Y axis. Each of the lubricating oil separating plates 71d is slightly smaller than the position between the baffle plate 71b and the portion closest to the baffle plate 71b on the baffle plate 71b side of the portion of the base portion 71a that forms the top surface TS. It extends to a plane located on the positive side of the Z-axis and perpendicular to the Z-axis.
The lubricating oil separation plates 71c and the lubricating oil separation plates 71d are arranged so as to be alternately arranged at predetermined intervals in the Y-axis direction.

  The seal member 71e is made of an elastic material (in this example, rubber). The seal member 71e is a string-like body having a rectangular cross-sectional shape. The seal member 71e is fixed to the side surface SS so as to surround the side surface SS of the first lubricant separating cartridge 71 in one plane orthogonal to the Z-axis. The seal member 71e is disposed such that the distance in the Z-axis direction between the seal member 71e and the claw portion 71a1 substantially matches the length of the protrusion 42c2 in the Z-axis direction.

  With such a configuration, in the state where the first lubricant separating cartridge 71 is attached to the head cover 42, the seal member 71e allows gas or lubricant to be discharged from the gap between the projection 42c2 and the claw 71a1 of the internal combustion engine 10. Prevent leakage to the outside.

  As described above, the sludge suppression layer SL is formed on the wall surface forming the PCV chamber R1 and the lubricating oil separating plate 71c and the lubricating oil separating plate 71d disposed in the PCV chamber R1. Accordingly, it can be said that “the sludge suppression layer SL is exposed to the circulation passage in a state where the first lubricant separating cartridge 71 is attached to the head cover 42”.

  The second lubricating oil separation cartridge 72 has the same configuration as the first lubricating oil separation cartridge 71. That is, the second lubricating oil separating cartridge 72 is a cross-sectional view of the second lubricating oil separating cartridge 72 taken along a plane including the line 7-7 in FIG. 4 and FIG. 2 and perpendicular to the X axis. 7, the base portion 72a, the baffle plate 72b, a plurality (two in this example) of lubricating oil separating plates 72c, and a plurality (three in this example) of lubricating oil. A separation plate 72d and a seal member 72e are provided. A sludge suppression layer SL is formed on the surface of the base portion 72a, the baffle plate 72b, the lubricating oil separating plate 72c, and the lubricating oil separating plate 72d, as with the first lubricating oil separating cartridge 71.

  A claw portion 72a1 is formed in the base portion 72a, similarly to the base portion 71a. Further, in the base portion 72a, in place of the communication hole 71a2 formed in the portion where the top surface TS of the base portion 71a is formed, a portion of the base portion 72a where the side surface SS on the Y axis negative direction side is formed. A communication hole 72a2 opened in the Y-axis negative direction is formed. The communication hole 72a2 is connected to the PCV chamber R2 formed by the baffle plate 72b and the base portion 72a. The PCV chamber R2 constitutes a part of the circulation passage.

  Further, the second lubricating oil separation cartridge 72 includes a flow rate control valve (PCV valve) 72f. The PCV valve 72f is inserted into the communication hole 72a2. The PCV valve 72f allows the PCV chamber R2 to communicate with the outside of the second lubricant separating cartridge 72 through the internal space. The PCV valve 72f can adjust the flow rate of the gas passing through the internal space.

  Similarly to the baffle plate 71b, the baffle plate 72b has a gas hole 72b1 and a lubricating oil hole 72b2.

  One end of the first circulation pipe 73 shown in FIG. 1 is connected to the intake duct 53 at a position upstream of the throttle valve 55 so that the internal space is connected to the intake passage. The other end of the first circulation pipe 73 is detachably connected to the first lubricant separating cartridge 71 so that the internal space is connected to the communication hole 71a2. The internal space of the first circulation pipe 73 constitutes a part of the circulation passage.

  One end of the second circulation pipe 74 is connected to the intake duct 53 at a position downstream of the throttle valve 55 so that the internal space is connected to the intake passage. The other end of the second circulation pipe 74 is detachably connected to the PCV valve 72f so that the internal space is connected to the internal space of the PCV valve 72f. The internal space of the second circulation pipe 74 constitutes a part of the circulation passage.

  With this configuration, the first circulation pipe 73 is removed from the first lubricating oil separation cartridge 71, and the first lubricating oil separation cartridge 71 is compressed in the X-axis direction and the first lubrication is performed. By applying a force for compressing the oil separating cartridge 71 in the Y-axis direction to the side surface SS of the base portion 71a, the base portion 71a and the baffle plate 71b are deformed, and the concave portion SB1 of the first lubricating oil separating cartridge 71 is obtained. Both the distance in the X-axis direction and the distance in the Y-axis direction of the opening of each of the apertures become shorter.

  Thus, the claw portion 71a1 can be moved to a position that does not face the protruding portion 42c2. Therefore, the first lubricant separating cartridge 71 can be removed from the head cover 42. That is, the first lubricant separating cartridge 71 is configured to be attachable to and detachable from the head cover 42 (engine body portion) in a state where the cylinder head portion 40 and the crankcase portion 30 are fixed to the cylinder block portion 20. Yes.

  Similarly, the second lubricating oil separating cartridge 72 is also configured to be detachable from the head cover 42 (engine body portion) in a state where the cylinder head portion 40 and the crankcase portion 30 are fixed to the cylinder block portion 20. ing.

  In the internal combustion engine 10 configured as described above, air is introduced into the combustion chamber 25 through the intake passage, and fuel injected by the injector 41e is introduced into the combustion chamber 25. Thereby, a mixed gas containing air and fuel is formed in the combustion chamber 25. The mixed gas in the combustion chamber 25 is ignited by the spark plug 41c generating a spark. As a result, combustion of the mixed gas occurs in the combustion chamber 25. As a result, the pressure of the gas in the combustion chamber 25 becomes extremely high.

  Thereby, a part of this gas leaks from the gap between the piston ring PR and the bore wall surface BS. This leaked gas is called blow-by gas. The blow-by gas passes through the cylinder bore 21, the crankshaft housing space SA1, and the internal passage PT1 in this order as shown by the arrow with the reference symbol A2 in FIG. 1, and reaches the cam housing space SA2.

  By the way, when the load required for the internal combustion engine 10 is relatively small, the throttle valve opening degree TA is relatively small. Accordingly, the pressure of the air in the intake passage upstream of the throttle valve 55 is substantially equal to the atmospheric pressure. On the other hand, the pressure of the air in the intake passage downstream of the throttle valve 55 is lower than the atmospheric pressure because the air is sucked into the combustion chamber 25.

  Accordingly, as indicated by the arrow labeled A1 in FIG. 1, the air in the intake passage upstream of the throttle valve 55 is converted into the first circulation pipe 73 and the first lubricant separating cartridge 71. Through the communication holes 71a2 in this order and flow into the PCV chamber R1. In the PCV chamber R1, air flows in the positive Y-axis direction. Further, the air in the PCV chamber R1 flows into the cam housing space SA2 through the gas hole 71b1.

  Thereby, blow-by gas and air are mixed in the cam housing space SA2. Accordingly, the concentration of harmful components such as hydrocarbon (HC), nitrogen oxide (NOx), and sulfur oxide (SOx) in the gas in the cam housing space SA2 is lower than the concentration of harmful components in the blow-by gas. .

  Further, the gas including the blow-by gas in the cam housing space SA2 flows into the PCV chamber R2 through the gas hole 72b1. In the PCV chamber R2, the gas flows in the negative Y-axis direction. At this time, when the gas collides with the lubricating oil separating plate 72c and the lubricating oil separating plate 72d, the mist-like lubricating oil contained in the gas adheres to the lubricating oil separating plate 72c and the lubricating oil separating plate 72d. . The adhering lubricating oil flows down in the negative direction of the Z-axis through the lubricating oil hole 72b2, and then returns into the oil pan 31. Thus, the mist-like lubricating oil contained in the gas in the PCV chamber R2 is removed from the gas.

  Then, the gas in the PCV chamber R2 flows into the intake passage through the internal space of the PCV valve 72f and the second circulation pipe 74 in this order, as indicated by the arrow with the symbol A3 in FIG. . As a result, the blow-by gas is reintroduced into the combustion chamber 25 and used for combustion, and then purified by the three-way catalyst device 62 disposed in the exhaust passage. Thereafter, the purified gas is discharged into the atmosphere (internal combustion engine 10). To the outside).

  On the other hand, when the load required for the internal combustion engine 10 is relatively high, the throttle valve opening TA is relatively large. Therefore, the pressure of air in the intake passage upstream of the throttle valve 55 and the pressure of air in the intake passage downstream of the throttle valve 55 are substantially the same.

  By the way, at the time of high load, more fuel is used for combustion than at the time of light load, so the pressure of the gas in the combustion chamber 25 after combustion becomes higher than that at the time of light load. As a result, the amount of blow-by gas also increases. Therefore, the blow-by gas pressure in the cam housing space SA2 also increases.

  As a result, the blow-by gas in the cam housing space SA2 flows into the PCV chamber R1 through the gas hole 71b1. And in PCV room R1, blowby gas flows toward the Y-axis negative direction. At this time, the mist-like lubricating oil contained in the gas in the PCV chamber R1 is removed from the gas by adhering to the lubricating oil separating plate 71c and the lubricating oil separating plate 71d.

  Then, the gas in the PCV chamber R1 flows into the intake passage through the communication hole 71a2 and the first circulation pipe 73 in this order, as indicated by the arrow with the symbol A4 in FIG. In addition, as in the case of a light load, as indicated by the arrow with the symbol A3 in FIG. 8, blow-by gas that has passed through the PCV chamber R2 also flows into the intake passage. As a result, the blow-by gas is reintroduced into the combustion chamber 25 and subjected to combustion, and then purified by the three-way catalyst device 62 disposed in the exhaust passage, and then the purified gas is released to the atmosphere. .

  Thus, according to the internal combustion engine 10, the blow-by gas is reintroduced into the combustion chamber 25. As a result, the pressure of the gas in the crankshaft housing space SA1 can be prevented from becoming excessively high, so that the blow-by gas can be prevented from leaking from the crankshaft housing space SA1 to the outside of the internal combustion engine 10. it can. That is, it is possible to prevent harmful components contained in blow-by gas from being released to the atmosphere as they are.

  Furthermore, in the internal combustion engine 10, the sludge suppression layer SL is formed on the wall surfaces forming the PCV chamber R1 and the PCV chamber R2. That is, the sludge suppression layer SL is exposed to the circulation passage. Thereby, even if an acidic substance is formed on the sludge suppression layer SL by NOx and / or SOx in the blow-by gas, the acidic substance is neutralized by the sludge suppression layer SL. Thereby, the production | generation of sludge can be suppressed.

  In addition, the first lubricating oil separation cartridge 71 and the second lubricating oil separation cartridge 72 as the sludge suppressing member are in a state where the crankcase portion 30 and the cylinder head portion 40 are fixed to the cylinder block portion 20. It is configured to be detachable from the engine body. Therefore, when the sludge suppression layer SL is deteriorated (that is, when the sludge suppression layer SL can no longer neutralize the acidic substance), the crankcase portion 30 and the cylinder head portion 40 (head cover 42) are replaced with the cylinder block portion 20. The sludge suppressing member can be exchanged without removing it from. That is, the trouble of replacing the sludge suppressing member can be reduced.

  In the internal combustion engine 10, the sludge suppression layer SL is formed at the tip of the foot portion FCa of the filler cap FC exposed in the cam housing space SA2. Thereby, the sludge suppression layer SL formed on the filler cap FC can be observed by removing the filler cap FC from the head cover 42 without removing the sludge suppression member from the engine body.

  Thereby, the deterioration state of the sludge suppression layer SL of the first lubricant separation cartridge 71 and the second lubricant separation cartridge 72 can be estimated based on the deterioration state of the sludge suppression layer SL of the filler cap FC. . In other words, the deterioration state of the sludge suppression layer SL of the sludge suppression member can be estimated by using the filler cap FC without providing another part. As a result, the sludge suppressing member can be replaced at an appropriate timing.

Second Embodiment
Next, an internal combustion engine according to a second embodiment of the present invention will be described. The internal combustion engine according to the second embodiment is different from the internal combustion engine according to the first embodiment in that the PCV chamber is disposed in the vicinity of the side wall of the cylinder block portion 20, and the sludge suppression member is formed integrally with the oil filter. The only difference is that the sludge suppression layer SL is formed on a part of the oil level gauge and the sludge suppression layer SL is exposed to the circulation passage. Accordingly, the following description will focus on such differences.

  As shown in FIGS. 9 and 10, the internal combustion engine 10 </ b> A according to the second embodiment includes a circulation passage forming unit 100 instead of the circulation passage forming unit 70. The circulation passage forming unit 100 includes an oil filter unit 101, a PCV chamber forming unit 102, a first circulation pipe 103, a second circulation pipe 104, and a third circulation pipe 105.

  The oil filter unit 101 is a cylindrical member. The oil filter unit 101 is fixed to the side wall of the cylinder block unit 20 on the X axis positive direction side. Oil filter section 101 is a cross-sectional view of oil filter section 101 cut along a plane along line 11-11 in FIG. 10 (a plane including the central axis of oil filter section 101 and perpendicular to the Z axis). As shown in Fig. 5, the oil filter 101a and the annular passage forming portion 101b as a sludge suppressing member are provided.

  The oil filter 101a is a columnar member having a central axis parallel to the X axis. A thread that is screwed into a thread groove (not shown) formed on the side wall of the cylinder block 20 is formed at the end of the side surface of the oil filter 101a on the X axis negative direction side.

  The oil filter 101a is formed with an inflow hole 101a1 and an outflow hole 101a2 that open on the surface on the X axis negative direction side. An internal passage PT2 that connects the inflow hole 101a1 and the outflow hole 101a2 is formed in the oil filter 101a. A filter paper PF for filtering the lubricating oil is disposed in the internal passage PT2.

The cylinder block 20 is formed with a passage (not shown) that connects the oil pump outlet and the inflow hole 101a1. Furthermore, a passage (not shown) that connects the outflow hole 101a2 and the lubricating oil distribution passage is formed in the cylinder block portion 20.
With such a configuration, the lubricating oil sent out from the oil pump flows into the internal passage PT2 through the inflow hole 101a1, passes through the filter paper PF, and then flows into the lubricating oil distribution passage through the outflow hole 101a2. .

  The annular passage forming part 101b is a hollow cylindrical member. The inner diameter of the annular passage forming portion 101b is slightly larger than the diameter of the oil filter 101a. The annular passage forming portion 101b is fixed so as to be rotatable relative to the side surface of the oil filter 101a through a known rolling bearing mechanism. That is, the annular passage forming portion 101b as the sludge suppressing member is formed integrally with the oil filter 101a.

  A hollow cylindrical annular passage SA3 that constitutes a part of the circulation passage is formed in the annular passage forming portion 101b. A sludge suppression layer SL is formed on the wall surface forming the annular passage SA3. The annular passage forming portion 101b is formed with an inflow hole 101b1 and an outflow hole 101b2 that communicate the annular passage SA3 and the outside of the annular passage forming portion 101b. The inflow hole 101b1 is disposed at the end of the annular passage forming portion 101b on the Y axis negative direction side. The outflow hole 101b2 is disposed at the end on the Y axis positive direction side of the annular passage forming portion 101b.

  As shown in FIG. 12, which is a cross-sectional view of the oil filter portion 101 cut along a plane along line 12-12 in FIG. 10, the wall on the outer diameter side of the annular passage forming portion 101b has a positive A through hole HL1 opening in the direction and a through hole HL2 opening in the Z-axis negative direction are formed. Each of the through hole HL1 and the through hole HL2 communicates the annular passage SA3 with the outside of the oil filter portion 101. Each of the through hole HL1 and the through hole HL2 has the same cross-sectional shape. Each of the through hole HL1 and the through hole HL2 is coaxially disposed in the vicinity of the end portion on the Y axis negative direction side of the annular passage forming portion 101b.

  As shown in FIG. 9, the PCV chamber forming part 102 is a rectangular parallelepiped member. Inside the PCV chamber forming portion 102, a PCV chamber R3 (not shown) that constitutes a part of the circulation passage is formed. In the PCV chamber R3, a lubricating oil separating plate (not shown) is disposed. An inflow hole and an outflow hole (not shown) are formed in the PCV chamber forming portion 102. The inflow hole is opened at the wall surface of the PCV chamber forming portion 102 on the Y axis negative direction side so as to communicate the PCV chamber R3 and the outside of the PCV chamber forming portion 102. The outflow hole is opened at the wall surface on the Z-axis positive direction side of the PCV chamber forming portion 102 so as to communicate the PCV chamber R3 and the outside of the PCV chamber forming portion 102.

  The first circulation pipe 103 has one end so that the crankshaft housing space SA1 and the internal space of the first circulation pipe 103 communicate with each other through a through hole (not shown) formed in the side wall of the cylinder block portion 20. Is connected to the side wall of the cylinder block portion 20. The other end of the first circulation pipe 103 is detachably connected to the annular passage forming part 101b so that the internal space is connected to the inflow hole 101b1 of the oil filter part 101. The first circulation pipe 103 forms part of the circulation passage.

  One end of the second circulation pipe 104 is detachably connected to the annular passage forming part 101b so that the internal space is connected to the outflow hole 101b2 of the oil filter part 101. The other end of the second circulation pipe 104 is connected to the PCV chamber forming portion 102 so that the internal space is connected to the inflow hole of the PCV chamber forming portion 102. Note that the second circulation pipe 104 forms a part of the circulation passage.

  One end of the third circulation pipe 105 is connected to the PCV chamber forming portion 102 so that the internal space is connected to the outflow hole of the PCV chamber forming portion 102. The other end of the third circulation pipe 105 is connected to the intake duct 53 on the downstream side of the throttle valve 55 so that the internal space is connected to the intake passage. The third circulation pipe 105 forms a part of the circulation passage.

  Furthermore, the internal combustion engine 10A includes an oil level gauge guide GG and an oil level gauge OG, as shown in FIGS.

  The oil level gauge guide GG is a hollow cylindrical member. As shown in FIG. 12, the oil level gauge guide GG is arranged such that its central axis is parallel to the Z axis and its central axis passes through the central axes of the through hole HL1 and the through hole HL2.

The oil level gauge guide GG includes an upper GGa and a lower GGb.
The upper GGa is fixed to the side wall of the cylinder block portion 20 as shown in FIGS. The end of the upper GGa on the Z axis negative direction side is made of an elastic member (in this example, rubber). The end of the upper GGa on the negative side in the Z-axis is in contact with the outer wall surface of the annular passage forming part 101b. With such a configuration, the upper GGa prevents the gas in the oil level gauge guide GG from leaking from the gap between the end of the upper GGa on the negative side in the Z-axis direction and the outer wall surface of the annular passage forming portion 101b. .

  The lower GGb is a through-hole formed in the cylinder block portion 20, and the cylinder so that the inner space of the lower GGb is connected to a through-hole HL 3 (not shown) that connects the crankshaft housing space SA 1 and the outside of the cylinder block portion 20. It is fixed to the side wall of the block part 20. The end of the lower GGb on the Z axis positive direction side is made of an elastic member (in this example, rubber). The end portion of the lower GGb on the positive side in the Z-axis is in contact with the outer wall surface of the annular passage forming portion 101b. With such a configuration, the lower GGb prevents the gas in the oil level gauge guide GG from leaking from the gap between the end of the lower GGb on the positive side in the Z-axis direction and the outer wall surface of the annular passage forming portion 101b. .

  The oil level gauge OG is inserted into the engine body through the oil level gauge guide GG. As shown in FIG. 12, the oil level gauge OG includes a handle portion OGa, a connection portion OGb, and a main body portion OGc.

  The handle portion OGa constitutes a portion of the oil level gauge OG that is located closest to the Z-axis positive direction. The handle portion OGa is located on the Z axis positive direction side with respect to the oil level gauge guide GG. The handle portion OGa is formed in a shape that can be easily grasped by a measurer who wants to measure the amount of lubricating oil.

  The connecting portion OGb constitutes a portion of the oil level gauge OG that is adjacent to the handle portion OGa on the Z-axis negative direction side. An annular seal member OGb1 is fixed to the outer wall of the connection part OGb. Seal member OGb1 is in sliding contact with the inner wall surface of oil level gauge guide GG. With such a configuration, the seal member OGb1 has a space on the positive side in the Z-axis direction relative to the seal member OGb1 in the internal space of the oil level gauge guide GG and a seal member OGb1 in the internal space of the oil level gauge guide GG. And the space on the negative side of the Z axis.

  The main body portion OGc constitutes a portion adjacent to the connection portion OGb on the Z-axis negative direction side in the oil level gauge OG. The main body OGc is a flat bar member. The main body OGc has the same cross-sectional shape as the cross-sectional shapes of the through hole HL1 and the through hole HL2. The main body portion OGc passes through the through hole HL1, the through hole HL2, and the through hole HL3. That is, a part of the main body OGc is exposed to the annular passage SA3.

  A sludge suppression layer SL is formed in a portion of the main body OGc exposed to the annular passage SA3. That is, it can be said that the sludge suppression layer SL is exposed to the circulation passage in a state where the oil level gauge OG is attached to the engine body. Further, as shown in FIG. 10, the main body portion OGc extends to the vicinity of the bottom surface of the oil pan 31 so as to reach the lubricating oil stored in the oil pan 31.

  As described above, the oil level gauge OG is an oil level gauge guide GG fixed to the cylinder block portion 20 in a state where the oil filter portion 101 as a sludge suppressing member is attached to the cylinder block portion 20 (engine body portion). It is comprised so that attachment or detachment is possible.

  With such a configuration, the measurer removes the oil level gauge OG from the engine main body and checks the position of the portion of the oil level gauge OG where the lubricating oil has adhered, thereby storing the oil level gauge OG in the oil pan 31. The amount of lubricating oil can be measured.

  Further, with the above-described configuration, the oil level gauge OG is removed from the oil level gauge guide GG, the first circulation pipe 103 and the second circulation pipe 104 are removed from the annular passage forming portion 101b, and the oil filter The oil filter part 101 is removed from the cylinder block part 20 by rotating the oil filter 101a to loosen the coupling state between the thread formed on the side surface of the 101a and the thread groove formed on the side wall of the cylinder block part 20. Can do. That is, the oil filter portion 101 is configured to be detachable from the cylinder block portion 20 (engine body portion) in a state where the cylinder head portion 40 and the crankcase portion 30 are fixed to the cylinder block portion 20.

  In the internal combustion engine 10A configured as described above, the blow-by gas in the crankshaft accommodating space SA1 passes through the first circulation pipe 103 and flows into the annular passage SA3 through the inflow hole 101b1. The blow-by gas in the annular passage SA3 flows into the second circulation pipe 104 through the outflow hole 101b2. Next, the blow-by gas flows into the PCV chamber R3 in the PCV chamber forming portion 102, and then flows into the intake passage through the third circulation pipe 105.

  As a result, the blow-by gas is reintroduced into the combustion chamber 25 and subjected to combustion, and then purified by the three-way catalyst device 62 disposed in the exhaust passage, and then the purified gas is released to the atmosphere. .

  Thus, according to the internal combustion engine 10A, the blow-by gas is reintroduced into the combustion chamber 25. As a result, the pressure of the gas in the crankshaft housing space SA1 can be prevented from becoming excessively high, so that the blow-by gas can be prevented from leaking from the crankshaft housing space SA1 to the outside of the internal combustion engine 10A. it can. That is, it is possible to prevent harmful components contained in blow-by gas from being released to the atmosphere as they are.

  Further, in the internal combustion engine 10A, a sludge suppression layer SL is formed on the wall surface forming the annular passage SA3. That is, the sludge suppression layer SL is exposed to the circulation passage. Thereby, even if an acidic substance is formed on the sludge suppression layer SL by NOx and / or SOx in the blow-by gas, the acidic substance is neutralized by the sludge suppression layer SL. Thereby, the production | generation of sludge can be suppressed.

  In addition, the annular passage forming portion 101b as a sludge suppressing member is configured to be detachable from the engine main body portion with the crankcase portion 30 and the cylinder head portion 40 fixed to the cylinder block portion 20. . Therefore, when the sludge suppression layer SL is deteriorated (that is, when the sludge suppression layer SL can no longer neutralize the acidic substance), the crankcase portion 30 and the cylinder head portion 40 are not removed from the cylinder block portion 20. The sludge suppressing member can be replaced. That is, the trouble of replacing the sludge suppressing member can be reduced.

  Furthermore, in the internal combustion engine 10A, the annular passage forming portion 101b as the sludge suppressing member is formed integrally with the oil filter 101a. Therefore, the annular passage forming portion 101b can be replaced at the same time when the oil filter 101a is replaced. Thereby, compared with the case where an annular passage formation part is exchanged independently with an oil filter, the effort which replaces oil filter 101a and annular passage formation part 101b can be reduced.

  Further, in the internal combustion engine 10A, in a state where the oil level gauge OG is attached (inserted) to the engine main body, the portion accommodated in the annular passage SA3 of the main body OGc of the oil level gauge OG. A sludge suppression layer SL is formed. Thus, the sludge suppression layer SL formed on the oil level gauge OG can be observed by removing the oil level gauge OG from the engine body without removing the sludge suppression member from the engine body.

  Thereby, the deterioration state of the sludge suppression layer SL of the annular passage formation part 101b can be estimated based on the deterioration state of the sludge suppression layer SL of the oil level gauge OG. That is, it is possible to estimate the deterioration state of the sludge suppression layer SL of the sludge suppression member by using the oil level gauge OG without providing another component. As a result, the sludge suppressing member can be replaced at an appropriate timing.

  In addition, in the said 2nd Embodiment, although the annular channel | path formation part 101b was arrange | positioned in the upstream of the PCV chamber formation part 102, you may arrange | position in the downstream of the PCV chamber formation part 102.

  Moreover, although the said 2nd Embodiment was provided with the PCV chamber formation part 102, the PCV chamber formation part 102 does not need to be provided. In this case, it is preferable that the lubricating oil separating plate is disposed in the annular passage SA3 in the annular passage forming portion 101b.

  In addition, this invention is not limited to said each embodiment, A various modification can be employ | adopted within the scope of the present invention.

1 is a schematic cross-sectional view of an internal combustion engine according to a first embodiment of the present invention. FIG. 2 is a perspective view of the head cover shown in FIG. 1. FIG. 3 is a view showing a vicinity of a head cover in a cross section obtained by cutting an internal combustion engine along a plane including a line 3-3 in FIG. 2. FIG. 4 is a diagram showing a vicinity of a head cover in a cross section obtained by cutting the internal combustion engine along a plane including line 4-4 in FIG. 2. FIG. 3 is a perspective view of the head cover in a state where a first lubricant separating cartridge and a second lubricant separating cartridge are removed from the head cover shown in FIG. 1. FIG. 6 is a cross-sectional view of the first lubricant separating cartridge taken along a plane including line 6-6 in FIG. 2; FIG. 7 is a cross-sectional view of the second lubricant separating cartridge taken along a plane including line 7-7 in FIG. 2. It is explanatory drawing which showed the flow of blow-by gas at the time of high load. It is a perspective view of the circulation passage formation part arrange | positioned at the side wall of the cylinder block part of the internal combustion engine which concerns on 2nd Embodiment of this invention. FIG. 10 is a front view of the internal combustion engine shown in FIG. 9 as viewed from the front. It is sectional drawing which cut | disconnected the oil filter part in the plane containing the 11-11 line | wire of FIG. It is sectional drawing which cut | disconnected the oil filter part, the oil level gauge, and the oil level gauge guide in the plane containing the 12-12 line | wire of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 10A ... Internal combustion engine, 20 ... Cylinder block part, 25 ... Combustion chamber, 30 ... Crankcase part, 31 ... Oil pan, 40 ... Cylinder head part, 41 ... Cylinder head, 42 ... Head cover, 42a ... Communication Hole 42b1... First communication hole 42b2 Second communication hole 42c1 Vertical wall portion 42c2 Projection portion 42c3 Vertical wall portion 42c4 Projection portion 70 Circulation passage forming portion 71 ... 1st lubricating oil separation cartridge, 71a ... base part, 71a1 ... claw part, 71b ... baffle plate, 72 ... second lubricating oil separation cartridge, 72a ... base part, 72a1 ... claw part, 72b ... baffle plate , 72f ... PCV valve, 100 ... circulation passage forming portion, 101 ... oil filter portion, 101a ... oil filter, 101b ... annular passage forming portion, FC ... fi -Cap, FCa ... foot, FCb ... head, GG ... oil level gauge guide, OG ... oil level gauge, OGc ... main body, R1 ... PCV chamber, R2 ... PCV chamber, SA1 ... crankshaft housing space, SA3 ... circle Ring passage, SL: Sludge suppression layer.

Claims (4)

A cylinder bore that is a cylindrical hole penetrating in a predetermined bore central axis direction is formed, and a cylinder block portion that accommodates a piston in the cylinder bore, and the cylinder block portion so as to cover one of the opening portions of the cylinder bore A cylinder head portion that is fixed and includes a head cover, and a crank shaft housing space that is a space for housing a crank shaft connected to the piston and that is connected to the cylinder bore at the other of the opening portions of the cylinder bore. A crankcase portion fixed to the cylinder block portion, and an engine body portion comprising
A mixed gas containing air and fuel is formed in a combustion chamber formed by the wall surface forming the cylinder bore, the cylinder head portion, and the piston, and the formed mixed gas is combusted in the combustion chamber. An internal combustion engine configured and formed with a circulation passage for reintroducing blowby gas, which is gas leaked from the combustion chamber into the crankshaft housing space, into the combustion chamber,
It has a sludge suppression layer made of a material that neutralizes acidic substances that promotes sludge generation, and is attached to and detached from the engine body in a state where the cylinder head part and the crankcase part are fixed to the cylinder block part. An internal combustion engine comprising a sludge suppressing member configured to be capable of being exposed to the circulation passage when the sludge suppressing layer is attached to the engine main body. The internal combustion engine according to claim 1,
The engine main body is formed with the circulation passage therein, and has a communication hole that communicates the circulation passage and the outside of the engine main body, and is supplied from the outside through the communication hole. The lubricating oil is configured to pass through a part of the circulation passage,
The sludge suppression member is configured to be detachable from the engine main body so as to open and close the communication hole in a state where the sludge suppression member is attached to the engine main body, and the sludge suppression layer is formed at least in part. An internal combustion engine comprising a filler cap configured to expose the sludge suppression layer to the circulation passage when attached to the engine main body. The internal combustion engine according to claim 1 or 2,
The crankcase portion has a lubricating oil reservoir that stores lubricating oil,
The sludge suppression member is configured to be detachable from the engine main body while being attached to the engine main body, and when the sludge suppressing member is attached to the engine main body, the tip is stored in the lubricating oil reservoir. The amount of the lubricating oil can be measured by reaching the lubricating oil, and the sludge suppressing layer is formed in the state where the sludge suppressing layer is formed at least partially and attached to the engine body. An internal combustion engine comprising an oil level gauge configured such that a layer is exposed to the circulation passage. The internal combustion engine according to any one of claims 1 to 3,
The sludge suppressing member is an internal combustion engine formed integrally with an oil filter that filters lubricating oil in the engine body.

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