阅读说明：本技术 窜缸混合气排出装置 (Blow-by gas discharge device ) 是由 五十岚修 于 2019-09-25 设计创作，主要内容包括：窜缸混合气排出装置包括加热室(24),其设于窜缸混合气配管的中途,形成于内燃机的飞轮壳体(10),并且对窜缸混合气进行加热。内燃机具备：将动力从曲轴(6)传递到凸轮轴(7)的动力传递机构(13)和容纳动力传递机构的机构室(14)。加热室隔着分隔壁(41)与机构室相邻,在分隔壁上设有用于使机构室内的机油滞留的滞留部(60)。(The blow-by gas discharge device is provided with a heating chamber (24) which is provided in the middle of the blow-by gas pipe, is formed in the flywheel housing (10) of the internal combustion engine, and heats the blow-by gas. An internal combustion engine is provided with: a power transmission mechanism (13) that transmits power from the crankshaft (6) to the camshaft (7), and a mechanism chamber (14) that houses the power transmission mechanism. The heating chamber is adjacent to the mechanism chamber with a partition wall (41) therebetween, and the partition wall is provided with a retention section (60) for retaining oil in the mechanism chamber.)

1. A blow-by gas discharge device comprising:

a blow-by gas pipe extending from a height position of an upper end portion to a height position of a lower end portion of the internal combustion engine, exposed to the outside air, and having an outlet portion opened to the atmosphere, and

a heating chamber that is provided in the middle of the blow-by gas pipe, that is formed in a flywheel housing of the internal combustion engine, and that heats blow-by gas;

the internal combustion engine includes a power transmission mechanism for transmitting power from a crankshaft to a camshaft, and a mechanism chamber for accommodating the power transmission mechanism;

the heating chamber is adjacent to the mechanism chamber with a partition wall interposed therebetween;

the partition wall is provided with a retention portion for retaining the engine oil in the mechanism chamber.

2. The blow-by gas discharge apparatus according to claim 1,

the partition wall is formed independently of the flywheel housing and fixed to the flywheel housing;

the retention portion is formed of at least one of a protruding portion protruding from the partition wall to the mechanism chamber side and a recessed portion recessed from the partition wall to the heating chamber side.

3. The blow-by gas discharge apparatus according to claim 1,

the heating chamber is formed by a hollow portion formed in the flywheel housing and a cover for closing an opening of the hollow portion;

the cover constitutes the partition wall and is formed of a metal plate.

4. The blow-by gas discharge apparatus according to claim 2,

the heating chamber is formed by a hollow portion formed in the flywheel housing and a cover for closing an opening of the hollow portion;

the cover constitutes the partition wall and is formed of a metal plate.

5. The blow-by gas discharge apparatus according to claim 3,

the retention portion is formed of a convex portion formed by deforming a part of the cover so as to protrude toward the mechanism chamber side, and a concave portion formed by deforming a part of the cover so as to recess toward the heating chamber side.

6. The blow-by gas discharge apparatus according to claim 3,

the retention portion is formed by a shelf member fixed to a surface of the cover on the mechanism chamber side.

7. The blow-by gas discharge apparatus according to claim 4,

the retention portion is formed of a convex portion formed by deforming a part of the cover so as to protrude toward the mechanism chamber side, and a concave portion formed by deforming a part of the cover so as to recess toward the heating chamber side.

8. The blow-by gas discharge apparatus according to claim 4,

the retention portion is formed by a shelf member fixed to a surface of the cover on the mechanism chamber side.

Technical Field

The present disclosure relates to a blow-by gas discharge device, and more particularly, to a device for discharging blow-by gas to the atmosphere through a blow-by gas pipe exposed to the outside air.

Background

Blow-by gas generated in a crank chamber of the internal combustion engine is generally returned to an intake system and delivered into a combustion chamber where it is burned together with the mixture.

Documents of the prior art

Patent document

Patent document 1: japanese Utility model laid-open No. Hei 1-95513

Disclosure of Invention

Technical problem to be solved by the invention

On the other hand, there is known a device that discharges blow-by gas to the atmosphere without returning it to the intake system (for example, see patent document 1). In this case, it is considered that a blowby gas pipe exposed to the outside air is provided from the height position of the upper end portion to the height position of the lower end portion of the internal combustion engine, and the blowby gas is discharged to the atmosphere through the blowby gas pipe.

However, in such a case, since the blow-by gas pipe is cooled by the outside air, the blow-by gas passing through the pipe is also cooled, and condensed water due to the blow-by gas is generated in the pipe. If the outside air temperature is below the freezing point, the condensed water may freeze and block the pipes.

The present disclosure provides a blow-by gas discharge device capable of suppressing freezing of condensed water in a blow-by gas pipe.

Means for solving the problems

According to an aspect of the present disclosure, a blow-by gas discharge device includes:

a blow-by gas pipe that extends from a height position of an upper end portion to a height position of a lower end portion of the internal combustion engine, is exposed to outside air, and has an outlet portion that is open to the atmosphere; and

a heating chamber which is provided in the middle of the blow-by gas pipe, is formed in a flywheel housing of the internal combustion engine, and heats blow-by gas,

the internal combustion engine is provided with: a power transmission mechanism that transmits power from the crankshaft to the camshaft; and a mechanism chamber accommodating the power transmission mechanism,

the heating chamber is adjacent to the mechanism chamber with a partition wall therebetween,

the partition wall is provided with a retention portion for retaining the engine oil in the mechanism chamber.

The partition wall may also be formed separately from the flywheel housing, and fixed to the flywheel housing,

the retention portion may be formed of at least one of a protrusion protruding from the partition wall toward the mechanism chamber side and a recess recessed from the partition wall toward the heating chamber side.

The heating chamber may be formed by a hollow portion formed in the flywheel housing and a cover for closing an opening of the hollow portion,

the cover may also constitute the partition wall and be formed of a metal plate.

The retention portion may be formed of a convex portion formed by deforming a part of the cover so as to protrude toward the mechanism chamber side, and a concave portion formed by deforming a part of the cover so as to recess toward the heating chamber side.

The retention portion may be formed of a shelf member fixed to a surface of the cover on the mechanism chamber side.

Effects of the invention

According to the present disclosure, freezing of condensed water in the blow-by gas piping can be suppressed.

Drawings

Fig. 1 is a vertical cross-sectional side view showing the structure of an end portion of an internal combustion engine.

Fig. 2 is a schematic longitudinal sectional rear view showing the heating chamber.

Fig. 3 is a vertical cross-sectional side view showing the structure of an end portion of the internal combustion engine according to modification 1.

Fig. 4 is a schematic vertical sectional rear view showing a heating chamber of modification 1.

Fig. 5 is a vertical cross-sectional side view showing the structure of an end portion of the internal combustion engine according to modification 2.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Further, it should be noted that the present disclosure is not limited to the following embodiments.

Fig. 1 is a side cross-sectional view showing the structure of an end portion of an internal combustion engine according to the present embodiment. The internal combustion engine (engine) 1 is a diesel engine mounted on a vehicle (not shown), and the vehicle is a large vehicle such as a truck. However, the type, use, and the like of the vehicle and the engine are not limited, and for example, the vehicle may be a small vehicle such as a car, and the engine may be a gasoline engine. The engine is disposed longitudinally of the vehicle. The front, rear, left, right, up and down directions of the vehicle and the engine are shown in the figure.

The engine 1 has: a cylinder block 2 integrally having a crankcase (not shown); a cylinder head 3 fastened to an upper end portion of the cylinder block 2; a head cover 4 fastened to an upper end portion of the cylinder head 3; and an oil pan 5 fastened to a lower end portion of the crankcase. The crankshaft 6 is rotatably supported by the crankcase, and the camshaft 7 is rotatably supported by the cylinder head 3.

A flywheel 8 is attached to a rear end surface portion of the crankshaft 6 by a plurality of bolts 9. A flywheel housing 10 that accommodates the flywheel 8 is attached to the cylinder block 2 by bolts or the like, not shown. Further, the flywheel housing 10 may be formed integrally with the cylinder block 2. A cylindrical flywheel chamber 11 is formed inside the flywheel housing 10, and the flywheel chamber 11 accommodates the flywheel 8 so as to be substantially rotatable. A clutch device, not shown, is connected to the rear end of the flywheel housing 10, and a clutch input shaft of the clutch device is coaxially coupled to the crankshaft 6. A part of the oil pan 5 is attached to the flywheel housing 10 by bolts 12.

A mechanism chamber in which a power transmission mechanism that transmits power from the crankshaft 6 to the camshaft 7 is housed is formed between the rear end surface portion of the cylinder block 2 and the flywheel housing 10. In the case of the present embodiment, the power transmission mechanism is formed by a gear mechanism 13 configured by meshing a plurality of gears, and the mechanism chamber is formed by a gear chamber 14. However, the power transmission mechanism may be of any type, and may be formed of, for example, a chain mechanism. The gear mechanism 13 includes: a crank gear 15 fixed to the crankshaft 6; a cam gear 16 fixed to the camshaft 7; and a plurality of (2 in the present embodiment) intermediate gears 17A and 17B interposed between the crank gear 15 and the cam gear 16. The gear chamber 14 communicates with a crank chamber 18 in the crankcase, a valve chamber 3A in the cylinder head 3, and a cover chamber 19 in the head cover 4.

C1 denotes the center axis of the crankshaft 6, and C2 denotes the center axis of the camshaft 7.

A gear chamber partition wall 20 having a half-frame shape (コ shape) in a plan view is integrally formed to protrude from the rear end portion of the cylinder head 3. The space inside the gear chamber partition wall 20 is a part of the gear chamber 14. The upper end surface of the flywheel housing 10 is closely attached to the lower end surface of the gear chamber partition wall 20, and the lower end surface of the cover 4 is closely attached to the upper end surface of the gear chamber partition wall 20.

The rear end of the crankshaft 6 protrudes rearward into the flywheel chamber 11 through an insertion hole 21 provided in the flywheel housing 10. A seal member (not shown) for preventing oil or gas from leaking from the gear chamber 14 is provided at the peripheral portion of the insertion hole 21.

As is well known, blow-by gas leaks from the combustion chamber in the cylinder into the crank chamber 18 through a gap between the piston ring and the cylinder bore. The blow-by gas is introduced into the housing chamber 19 through the gear chamber 14 or other gas passing holes.

On the other hand, an oil separator 22 that separates oil from blow-by gas is formed in the cover chamber 19. Although not shown, a serpentine passage through which blow-by gas flows is formed in the oil separator 22. In the case of the present embodiment, the blow-by gas from which the oil has been separated by the oil separator 22 is discharged to the atmosphere through the gas pipe 23 serving as a blow-by gas pipe.

The gas pipe 23 is exposed to the outside air and directly cooled by the outside air. In particular, the gas pipe 23 of the present embodiment is formed of a metal such as stainless steel, and the entire pipe is exposed to the outside air and is easily cooled by the outside air. In this case, the blow-by gas passing through the gas pipe 23 is also cooled, and condensed water due to the blow-by gas is generated in the gas pipe 23. Further, for example, if the outside air temperature is below the freezing point in a cold region or the like, the condensed water may freeze to block the inside of the gas pipe 23. If the gas pipe 23 is clogged, there is a possibility that the blow-by gas may be obstructed from being discharged.

Therefore, in the present embodiment, the heating chamber 24 that heats the blow-by gas is provided in the middle of the gas pipe 23, and the blow-by gas is heated in the heating chamber 24, whereby the generation and freezing of condensed water due to the blow-by gas is suppressed. In particular, the heating chamber 24 is formed inside the flywheel housing 10, is adjacent to the gear chamber 14 with a partition wall (a lid 41 described later in this embodiment) therebetween, and heats the blow-by gas mainly by heat received from the oil in the gear chamber 14. This makes it possible to efficiently heat the blow-by gas without providing a dedicated heat source. The structure of such a blow-by gas discharge device will be described in detail below.

The gas pipe 23 extends from the height position of the upper end portion to the height position of the lower end portion of the engine 1 as a whole. However, the gas pipe 23 is divided into two parts at a position halfway in the height direction, and is divided into an upstream side gas pipe 25 and a downstream side gas pipe 26 (indicated by a phantom line (dashed-dotted line) in fig. 1). A heating chamber 24 is connected between the upstream gas pipe 25 and the downstream gas pipe 26. The upstream gas pipe 25 and the downstream gas pipe 26 are both made of metal such as stainless steel, and are exposed to the outside air outside the engine.

The inlet 27 of the upstream-side gas pipe 25 is connected to the oil separator 22. The head cover 4 is provided with an outlet 28 for taking out the blow-by gas from which the oil has been separated by the oil separator 22, and the inlet 27 of the upstream gas pipe 25 is connected to the outlet 28. The inlet 27 of the upstream side gas pipe 25 constitutes an inlet of the gas pipe 23. The head cover 4 and the oil separator 22 are provided at the height position of the upper end portion of the engine 1, and since the inlet portion 27 of the upstream side gas pipe 25 is connected to the oil separator 22, the gas pipe 23 extends downstream from the height position of the upper end portion of the engine 1.

The oil separator 22 may be provided outside, not inside the head cover 4. Reference numeral 22A in the drawing denotes a delimiting wall that delimits the oil separator 22.

On the other hand, as shown in fig. 2, the outlet portion 29 of the upstream gas pipe 25 is connected to the heating chamber 24. An inlet 30 for introducing the blowby gas into the heating chamber 24 is provided at the upper end portion and the right end portion of the heating chamber 24, and the outlet portion 29 of the upstream side gas pipe 25 is connected to the inlet 30.

The inlet 31 of the downstream gas pipe 26 is also connected to the heating chamber 24. An outlet 32 for discharging the blow-by gas from the heating chamber 24 is provided at the upper end and the left end of the heating chamber 24, and the inlet 31 of the downstream side gas pipe 26 is connected to the outlet 32.

On the other hand, as shown in fig. 1, the downstream gas pipe 26 extends downward while passing through the left side of the flywheel housing 10 as it goes to the downstream side. The outlet 33 of the downstream gas pipe 26 is disposed at a height of the lower end of the engine 1, and is opened to the atmosphere in a downward state. This can suppress engine fouling due to blow-by gas discharged from the outlet portion 33. The outlet portion 33 of the downstream side gas pipe 26 constitutes the outlet portion of the gas pipe 23. Therefore, the gas pipe 23 extends to the height position of the lower end portion of the engine 1.

The heating chamber 24 is formed in the flywheel housing 10 at the upper end thereof. The heating chamber 24 is mainly defined by a cavity 40 and a lid 41, the cavity 40 being formed in the flywheel housing 10 and being open toward the front, and the lid 41 closing a front end opening of the cavity 40. The flywheel housing 10 is cast from aluminum or iron, while the cover 41 is formed from any metal plate. However, the material of the cover 41 is preferably a material having excellent heat resistance and corrosion resistance and high thermal conductivity, for example, aluminum. The cover 41 is superposed on the cover attachment surface 42 of the flywheel housing 10 positioned around the front end opening of the cavity 40, and is detachably and airtightly fixed by a plurality of bolts 43.

As shown in fig. 2, the heating chamber 24 of the present embodiment has a fan shape or a substantially fan shape extending around the crankshaft center axis C1 in a rear view seen from the rear (i.e., one end side in the direction of the crankshaft center axis C1). The same applies to the rear view shape of the cover 41. An inlet 30 is provided on the right side of the upper end of the heating chamber 24, and an outlet 32 is provided on the left side of the upper end. The central axes of the inlet 30 and the outlet 32 are substantially along the radial direction with respect to the crankshaft central axis C1.

Partition wall 44 forming a serpentine passage in heating chamber 24 is provided inside heating chamber 24. The partition wall 44 is formed integrally with the flywheel housing 10. As shown in fig. 1, partition wall 44 integrally and linearly protrudes forward from rear inner wall surface 45 of heating chamber 24, which is the bottom surface of hollow portion 40, and is in airtight contact with lid 41, thereby partitioning the space in heating chamber 24 vertically. As shown in fig. 2, partition wall 44 extends integrally and arcuately to the right from left inner wall surface 46 of heating chamber 24, which is one side surface of hollow 40, and terminates at a position where a predetermined gap 48 is formed with right inner wall surface 47 of heating chamber 24, which is the other side surface of hollow 40.

The outlet of the introduction port 30 faces the gap 48 and the lower inner wall surface 49 of the heating chamber 24. Thus, as indicated by the solid arrows, the introduction port 30 linearly conveys the blow-by gas discharged from the introduction port 30 to the space 50 below the partition wall 44 through the gap 48.

As shown in fig. 1, heating chamber 24 and flywheel chamber 11 are vertically overlapped, and a lower end portion of heating chamber 24 is disposed in front of an upper end portion of flywheel chamber 11. In the space 50 below the heating chamber 24, a step 51 protruding forward is provided on the rear inner wall surface 45 of the heating chamber 24. The step 51 can form the flywheel chamber 11 of a sufficient size on the rear back side of the rear inner wall surface 45 while avoiding the flywheel 8.

The shape of heating chamber 24 is not limited to the above shape, and may be changed to any shape. The partition wall 44 may be provided not in one but in plural as in the present embodiment. The step 51 may not be provided if possible.

The cover 41 constitutes a partition wall that partitions the heating chamber 24 and the gear chamber 14. In particular, the cover 41 of the present embodiment is provided with a retention portion for retaining the oil in the gear chamber 14. The retention portion of the present embodiment is formed by a protruding portion protruding from the cover 41 toward the gear chamber 14 side, specifically, a protruding portion 60, and the protruding portion 60 is formed by deforming a part of the cover 41 so as to protrude toward the gear chamber 14 side. The convex portion 60 can be easily formed in the cover 41 by press working or the like, and the cover 41 is a metal plate formed separately from the flywheel housing 10 in advance. By providing such a convex portion 60, the high-temperature oil in the gear chamber 14 can be retained on the upper surface of the convex portion 60, and heat transfer from the oil to the lid can be promoted, and the blow-by gas in the heating chamber 24 can be further heated.

As shown in fig. 1, the upper surface of the convex portion 60 is a shelf surface 61 extending straight in the front-rear direction. The shelf plate surface 61 captures and retains oil in the gear chamber 14 that has splashed toward the cover 41 and oil that has flowed down from above along the front surface, which is the surface of the cover 41 on the gear chamber 14 side. As shown in fig. 1, the side cross-sectional shape of the convex portion 60 of the present embodiment is a triangle, but it may be any shape. The number of the convex portions 60 in the present embodiment is 3 in the vertical direction at substantially equal intervals, but the number and arrangement thereof are arbitrary. In order to promote the oil retention effect, the side cross-sectional shape of the shelf plate surface 61 may be a concave shape with a depressed center.

As shown in fig. 2, convex portion 60 is formed in an arc shape extending around crankshaft center axis C1 in correspondence with the fan shape of heating chamber 24. The region of the angle θ in the center of heating chamber 24 is a convex portion forming region. Further, since the convex portion 60 is formed by pressing the metal plate to be depressed from the heating chamber 24 side to the gear chamber 14 side, the back side of the convex portion 60 in the heating chamber 24 is a concave portion of course. In order to promote the oil retention effect, the convex portion 60 may extend horizontally in the left-right direction, or may have an arc shape that is vertically reversed from the illustrated example.

The flow of blow-by gas in the configuration of the present embodiment is shown by solid arrows in fig. 1 and 2. The blow-by gas from which the oil has been separated by the oil separator 22 flows into the heating chamber 24 through the upstream gas pipe 25 and the introduction port 30. As shown in fig. 2, in the heating chamber 24, the blow-by gas discharged from the introduction port 30 linearly and smoothly enters the lower space 50 through the gap 48. The blow-by gas once moves to the left side in the lower space 50, then turns U-shaped to the right side, rises in the gap 48, and enters the upper space 52 partitioned by the partition wall 44. Then, the air advances to the left side in the upper space 52, and is discharged into the downstream air tube 26 from the discharge port 32. Then, the blow-by gas flows through the downstream gas pipe 26, and is discharged to the outside air through the outlet portion 33 (i.e., atmospheric release).

As described above, the blowby gas can be made to meander in the heating chamber 24, and the mixture can be temporarily retained.

On the other hand, high-temperature oil in the gear chamber 14 that lubricates the gear mechanism 13 adheres to the flywheel housing 10 and the cover 41, and the flywheel housing 10 and the cover 41 are heated by the oil. Therefore, the blow-by gas in the heating chamber 24 can be heated, kept warm, or at least suppressed from decreasing in temperature by the heat. Therefore, the generation of condensed water due to condensation of moisture contained in the blow-by gas, the freezing of the condensed water in the gas pipe 23, and the clogging of the gas pipe 23 due to the freezing can be suppressed. Since the blowby gas is meandering and stays in the heating chamber 24, it is advantageous to extend the heating time and suppress the generation of condensed water.

In particular, the blow-by gas tends to be cooled by the outside air as it goes downstream in the gas pipe 23 exposed to the outside air, and its temperature tends to decrease. The most serious is at the outlet portion 33 of the downstream side gas pipe 26 where the temperature of the blow-by gas is lowest. On the other hand, outside air including traveling wind enters the outlet portion 33, and the temperature of the outside air entering the outlet portion 33 is also very low in a cold region or the like. In this case, condensed water is likely to be generated and frozen in the outlet portion 33.

However, according to the configuration of the present embodiment, since the blowby gas can be heated in the heating chamber 24 in the middle of the gas pipe 23, the temperature of the blowby gas when reaching the outlet portion 33 can be increased, and the generation and freezing of the condensed water in the interior of the outlet portion 33 can be effectively suppressed.

Further, according to the configuration of the present embodiment, as shown by broken line arrows in fig. 1, oil scattered from the gears 15, 16, 17A, and 17B rotating in the gear chamber 14 and oil overflowing rearward from the valve chamber 3A in the cylinder head 3 fall down to adhere to the cover 41 and flow down along the front surface of the cover 41. In the case where the lid 41 does not have the projection 60, the oil flowing down easily passes through the lid 41, but in the case of the present embodiment, since the projection 60 is provided, the oil adhering and flowing down can be captured and accumulated on the shelf plate surface 61. Therefore, as compared with the case without the projection 60, the amount of heat transfer from the oil to the lid 41 can be increased, and the temperature of the lid 41 can be further increased, so that the blow-by gas in the heating chamber 24 can be further heated.

The cover 41 serving as the partition wall may be regarded as a part of the flywheel housing 10 divided in advance from the flywheel housing 10. In the case thus explained, the cover 41 as the partition wall is divided from the flywheel housing 10 and fixed to the flywheel housing 10. By dividing the partition wall in this manner, the retention portion can be provided in the partition wall before the partition wall is fixed to the flywheel housing 10, and therefore the retention portion can be easily provided.

In the present embodiment, the cover 41 is formed of a metal plate, and the convex portion 60 is provided by deforming a part of the cover 41. This makes it possible to easily provide the retention portion on the partition wall.

Of course, the partition wall may not necessarily be formed separately, and may be formed integrally with the flywheel housing. The retention portion may be formed integrally with the flywheel housing as the partition wall by casting or the like.

The cover 41 may not necessarily be a metal plate, and may be a cast product similar to the flywheel housing 10.

According to the configuration of the present embodiment, since heating chamber 24 is formed by cavity 40 and cover 41 for closing the cavity, heating chamber 24 can be easily formed. Further, since the lid 41 is detachable, the lid 41 can be detached if necessary to inspect and repair the inside of the heating chamber 24.

Next, a modified example will be described. Note that, in the drawings, the same reference numerals are given to the same portions as those of the above-described basic embodiment, and description thereof is omitted, and the differences from the basic embodiment will be mainly described below.

In the modification 1 shown in fig. 3 and 4, the retention portion for retaining oil is formed by a frame plate member 70 fixed to the front surface of the cover 41 on the gear chamber 14 side. The shelf member 70 constitutes a protruding portion that protrudes from the cover 41 toward the gear chamber 14 side. The shelf member 70 is formed in a plate shape, specifically, a shelf formed of a metal plate, and is fixed to the front surface of the cover 41 by an appropriate means such as welding, screwing, or the like. The upper surface of the shelf member 70 is a shelf surface 71 extending straight in the front-rear direction. As shown in fig. 4, the shelf member 70 is formed in an arc shape extending by an angle θ around the crankshaft center axis C1 in correspondence with the fan shape of the heating chamber 24.

The shelf member 70 may be a block-shaped member having a larger thickness in the vertical direction. The number of the shelf plate members in this modification is 3 in the vertical direction at substantially equal intervals, but the number and arrangement thereof can be arbitrarily changed. In order to promote the oil retention effect, the side cross-sectional shape of the shelf plate surface 71 shown in fig. 3 may be a concave shape with a central depression. In order to promote the oil retention effect, the rear view shape of the shelf plate member 70 shown in fig. 4 may be a shape extending horizontally in the left-right direction, or may be an arc shape which is vertically reversed from the illustrated example.

The present modification also exhibits the same operational advantages as the basic embodiment.

Next, a 2 nd modification will be described. In the modification 2 shown in fig. 5, the retention portion for retaining oil is formed by a recess recessed toward the heating chamber 24 from the lid 41 as a partition wall, specifically, by a recess 80, and the recess 80 is formed by deforming a part of the lid 41 so as to be recessed toward the heating chamber 24. The recess 80 can be easily formed in the cover 41, which is a metal plate, by press working or the like.

The inner lower surface of the recess 80 is a shelf plate surface 81 extending linearly in the front-rear direction.

The shelf surface 81 captures and retains oil that has splashed toward the cover 41 and oil that has flowed down from above along the front surface of the cover 41. The recess 80 of the present modification has a triangular side cross-sectional shape, but may have any shape. The number and arrangement of the recesses 80 can be changed arbitrarily. In order to promote the oil retention effect, the side cross-sectional shape of the shelf plate surface 81 may be a concave shape with a central depression. Although not shown, recess 80 has an arc-like rear view extending around crankshaft center axis C1 in accordance with the fan-like shape of heating chamber 24. However, the rear view shape of the recess 80 may be a shape extending horizontally in the left-right direction, or may be an arc shape protruding downward.

The present modification also exhibits the same operational advantages as the basic embodiment.

While the embodiments of the present disclosure have been described in detail above, the present disclosure may be implemented in other embodiments as follows.

(1) For example, the shelf plate surfaces 61, 71, 81 may be slightly inclined forward or backward with respect to the front-rear direction. If the oil is tilted forward, the effect of retaining the oil is impaired, but the oil flows down smoothly. Conversely, if the engine is tilted backward, the effect of retaining the engine oil and the effect of heating the engine oil are enhanced.

(2) The retention portion is not limited to the laterally elongated shape as described above, and may be a dot shape. The dot-like retention portions may be provided on the mechanism chamber side surface of the partition wall in any arrangement such as a lattice, a staggered arrangement, or a random arrangement.

The configurations of the above embodiments and modifications can be combined partially or entirely without any particular contradiction. The embodiments of the present disclosure are not limited to the above-described embodiments, and all modifications, applications, and equivalents included in the idea of the present disclosure defined by the scope of protection are included in the present disclosure. Therefore, the present disclosure should not be construed restrictively, but can be applied to any other techniques within the scope of the idea of the present disclosure.

The present application is based on the japanese patent application published on 27/9/2018 (japanese application 2018-182122), the contents of which are hereby incorporated by reference.

Industrial applicability

According to the present disclosure, freezing of condensed water in the blow-by gas piping can be suppressed.

Description of the reference numerals

1 internal combustion engine (Engine)

6 crankshaft

7 camshaft

10 flywheel casing

13 Gear mechanism

14 gear chamber

22 engine oil separator

23 gas pipe

24 heating chamber

27 inlet part

33 outlet part

41 cover

60 convex part

70 frame plate member

80 recess