JP2005016333A - Breather device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a breather device for an internal combustion engine whose intake amount of oil mist is small and which can be mounted without increasing height and overall width of an internal combustion engine. <P>SOLUTION: The gas-liquid separation chamber for separating oil in gas discharged from the crank chamber is provided in the side of a cylinder block or a cylinder head on the opposite side to a cam chain chamber or a push rod chamber with respect to a cylinder hole. The internal combustion engine is equipped with a generator chamber for accommodating an AC generator driven by the crank shaft in the end of the crank shaft. While the gas-liquid separation chamber for separating oil in gas discharged from the crank chamber is provided to the side of a cylinder block or a cylinder head and the upper side of the generator chamber, the crank chamber is communicated with the generator chamber which is communicated with the inlet side of the gas-liquid separation chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, in a four-stroke cycle internal combustion engine, relaxes fluctuations in the internal pressure of the crank chamber to smooth the movement of the piston, recirculates the blow-by gas to the combustion chamber, and separates oil in the gas to the crank chamber. It relates to a breather device for returning.
[0002]
[Prior art]
The breather device aims to smooth the movement of the piston by discharging air in the crank chamber when the internal pressure of the crank chamber increases and introducing air into the crank chamber when the internal pressure of the crank chamber decreases when operating the internal combustion engine. The crank chamber breathing device. In accomplishing this objective, the following two items that accompany it are considered.
[0003]
In a four-stroke cycle internal combustion engine, blow-by gas flows out of the combustion chamber into the crank chamber through a gap between the piston ring and the inner wall surface of the cylinder liner in a stroke in which the piston reciprocates in the cylinder. Most of this blow-by gas is an air-fuel mixture generated in the compression stroke, and contains a large amount of air pollutant hydrocarbon (HC). Generally, in order to prevent air pollution, blow-by gas is guided to the intake system, mixed with the intake air, recirculated to the combustion chamber, and burned. When the internal pressure of the crank chamber decreases when the piston moves up, fresh air is introduced from the intake system into the crank chamber.
[0004]
Further, during operation of the internal combustion engine, the lubricating oil in the crank chamber is vigorously agitated by the high speed rotation of the crankshaft and the power transmission gear to become oil mist, which fills the crank chamber. For this reason, when air is discharged from the crank chamber, oil mist is also discharged at the same time. Therefore, in general, a gas-liquid separation chamber is provided on the air discharge path to prevent the oil from being discharged from the exhaust air. Separate and return to the crankcase. The gas-liquid separation chamber is a chamber in which the inside is partitioned by a baffle plate to form a labyrinth flow path, and a gas discharge port is provided at the upper portion and an oil discharge port is provided at the lower portion.
[0005]
The configuration of a breather device for a general four-stroke cycle internal combustion engine is as described above, but various phases of the installation location of the air discharge path from the crank chamber and the gas-liquid separation chamber provided on the air discharge path Various breather apparatuses have been proposed depending on the combination of various positions of installation positions and structures.
[0006]
As a conventional technique, it is known to provide a gas-liquid separation chamber inside an internal combustion engine cylinder head cover (see, for example, Patent Document 1). In this configuration, since the overall height of the cylinder portion is increased, when the internal combustion engine is mounted on a motorcycle, there is a problem that mountability on the frame is lowered.
An example in which a gas-liquid separation chamber is provided inside the cam chain chamber is known (for example, see Patent Document 2). In the case of a motorcycle, the volume of the empty space in the cam chain chamber is very small, so it is impossible to provide a gas-liquid separation chamber with sufficient oil separation capacity unless the cam chain chamber is expanded to the side. There is a problem that there is a problem that the amount of oil mist sucked is large.
[0007]
[Patent Document 1]
Japanese Patent Laying-Open No. 2003-90205 (FIGS. 3 and 5)
[Patent Document 2]
Japanese Patent Publication No. 7-99088 (FIGS. 1 and 2).
[0008]
[Problems to be solved]
The present invention is intended to solve the above-described problems of the prior art, and to provide a breather device that can be installed without increasing the height and overall width of an internal combustion engine with a small amount of oil mist suction.
[0009]
[Means for solving the problems and effects]
The present invention solves the above-mentioned problems, and the invention according to claim 1 is a breather device for a four-stroke cycle internal combustion engine, wherein the cylinder block is located on the opposite side of the cylinder hole from the cam chain chamber or push rod chamber. Alternatively, a gas-liquid separation chamber for separating oil in the gas discharged from the crank chamber is provided on the side of the cylinder head.
[0010]
Since the present invention is configured as described above, the gas passage of the breather device can form an independent dedicated gas passage away from the cam chain chamber or the push rod chamber. It is possible to construct a breather device that does not suck oil flowing through the system and has a small amount of oil mist suction.
[0011]
According to a second aspect of the present invention, there is provided a breather device for an internal combustion engine according to the first aspect, wherein the gas-liquid separation chamber is provided integrally with a side of a cylinder block or a cylinder head. The gas-liquid separation chamber lid member is attached to the main body, and the gas-liquid separation chamber lid member is attached from the side of the cylinder block or cylinder head.
[0012]
Since the present invention is configured as described above, the gas-liquid separation chamber can be installed without increasing the height and overall width of the internal combustion engine, and the gas-liquid separation chamber can be disassembled from the outside of the internal combustion engine. Maintenance becomes easy.
[0013]
According to a third aspect of the present invention, there is provided a breather device for a four-stroke cycle internal combustion engine having a generator chamber that houses an AC generator driven by the crankshaft at an end of the crankshaft. A gas-liquid separation chamber for separating oil in the gas discharged from the crank chamber is provided on the side and above the generator chamber, the crank chamber is in communication with the generator chamber, and the generator chamber is It is characterized in that it communicates with the inlet side of the liquid separation chamber.
[0014]
Since the present invention is configured as described above, the generator chamber with less splashed oil is interposed between the gas-liquid separation chamber and the crank chamber, and the inlet of the gas-liquid separation chamber is communicated with the generator chamber. The flow of oil mist into the gas-liquid separation chamber can be reduced, and effective gas-liquid separation can be achieved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view of an internal combustion engine 1 on which the breather device of the present invention is mounted (partially has a longitudinal section), and FIG. 2 is a top view of the cross section of the internal combustion engine (II-II sectional view of FIG. 1). It is. The internal combustion engine 1 is a four-stroke cycle V-type two-cylinder internal combustion engine, and has two cylinders, a first cylinder 2A and a second cylinder 2B, and is V-shaped at intervals of 90 °. The left cylinder when the internal combustion engine is viewed from above is the first cylinder 2A, and when viewed from the side, the cylinder is inclined slightly upward and rearward. The cylinder on the right side when viewed from above is the second cylinder 2B, and is inclined toward the front slightly upward when viewed from the side. FIG. 1 shows a first cylinder 2A and a second cylinder 2B, and a gas-liquid separation chamber 50 of the breather device of the present invention is shown on the side of the first cylinder 2A. In FIG. 2, only the second cylinder 2B is shown in cross section.
[0016]
In FIG. 2, the crankcase 3 is divided into left and right parts, and includes a left crankcase 3L and a right crankcase 3R. Since the internal structures of the first cylinder 2A and the second cylinder 2B are the same, the structure will be described based on the second cylinder 2B shown in FIG. 2 without distinguishing the reference numerals of both cylinders. The cylinder outer shell includes a cylinder block 4, a cylinder head 5, and a cylinder head cover 6. The reciprocating motion of the piston 8 slidably fitted in each cylinder hole 7 of the cylinder block 4 is transmitted to the left and right crankshaft 10 rotatably supported by the crankcase 3 via the connecting rod 9. The shaft 10 rotates. A rotor 44 of an AC generator (ACG) 45 is fixed to the left end portion of the crankshaft 10, and the left side thereof is covered with a generator cover 41 coupled to the left crankcase 3L. Although the structure of the first cylinder 2A is not shown in FIG. 2, only the large end portion 9x of the connecting rod of the first cylinder appears in the drawing.
[0017]
In FIG. 2, the cylinder head 5 is provided with a valve mechanism. A camshaft 13 is rotatably supported by the cylinder head 5, and is camped over a drive sprocket 14 fixed to the right end of the crankshaft 10 and a driven sprocket 15 fixed to the right end of the camshaft 13. Thus, the camshaft 13 is rotationally driven at a reduction ratio of 1/2 that of the crankshaft 10. An intake cam 13a and an exhaust cam 13b provided integrally with the cam shaft 13 open and close the intake valve and the exhaust valve, respectively. After the fuel injected from the fuel injection valve into the intake passage passes through the intake valve together with air, the fuel is sucked into the combustion chamber 17 and ignited by the spark plug 18 to burn, and then the burned gas passes through the exhaust valve and passes through the exhaust passage. To be discharged.
[0018]
Next, the transmission will be described with reference to FIG. The transmission is housed in a transmission case. The transmission case is composed of three members: a left transmission case 20L, a right transmission case 20R, and a gear cover 21. The left transmission case 20L is fixed to the right crankcase 3R by bolts 22, the right transmission case 20R is fixed to the left transmission case 20L by bolts 23, and the gear cover 21 is fixed to the left transmission case 20L by bolts 24. Has been.
[0019]
The transmission is provided with four rotating shafts, that is, a driving pulley shaft 25, a driven pulley shaft 26, an intermediate shaft 27, and an output shaft 28. The drive pulley shaft 25 is supported by a right crankcase 3L, a left crankcase 3R, and a right transmission case 20L via a ball bearing, and the driven pulley shaft 26 is a ball bearing by the left transmission case 20L and the right transmission case 20R. The intermediate shaft 27 is supported via a ball bearing by the gear cover 21 and the left transmission case 20L, and the output shaft 28 is supported via a ball bearing by the gear cover 21 and the left transmission case 20L. Has been.
[0020]
A drive gear 30 is fixed to the crankshaft 10, and a driven gear 31 is fixed to a portion of the drive pulley shaft 25 in the crank chamber 11. The both gears are engaged. As a result, the drive pulley shaft 25 is rotationally driven by the crankshaft 10.
[0021]
A driving pulley 32 that rotates together with the driving pulley shaft 25 is attached to the driving pulley shaft 25, and a driven pulley 33 that is rotatable relative to the driven pulley shaft 26 is attached to the driven pulley shaft 26. A V-belt 34 is wound around. As a result, the rotation of the drive pulley shaft 25 is transmitted to the driven pulley 33 via the drive pulley 32.
[0022]
Further, a centrifugal start clutch 35 is attached to the driven pulley shaft 26 between the driven pulley 33 and the driven pulley shaft 26. When the rotational speed of the crankshaft 10 becomes greater than a predetermined value, the rotation of the driven pulley 33 also increases, whereby the start clutch 35 is connected and the driven pulley shaft 26 is rotationally driven. The drive pulley 32, the V belt 34, the driven pulley 33, and the starting clutch 35 constitute a V belt type transmission.
[0023]
A gear train is provided between the driven pulley shaft 26 and the output shaft 28. This is a small gear 36 provided integrally at the left end of the driven pulley shaft 26, an intermediate gear 37 provided integrally with the intermediate shaft and meshing with the small gear, and an output shaft gear fixed to the output shaft 28. There are 38 three gears. The rotation of the driven pulley shaft 26 is transmitted to the output shaft 28 by these gears. The small gear 36, the intermediate gear 37, and the output shaft gear 38 constitute a gear reduction device.
[0024]
A rear wheel drive shaft (not shown) provided with a drive sprocket is rotatably provided on the same axis as the output shaft 28 outside the left end of the output shaft 28 and is connected to the left end of the output shaft 28. A driven sprocket is provided on the rear wheel shaft (not shown) of the vehicle, and a chain is wound around the drive sprocket. The rear wheels of the vehicle are rotationally driven by the crankshaft 10 via the drive pulley shaft 25, the driven pulley shaft 26, the intermediate shaft 27, the output shaft 28, the rear wheel drive shaft and the rear wheel shaft.
[0025]
Next, the generator room 40 and the internal configuration will be described with reference to FIGS. The generator chamber 40 is provided on the left side of the crankcase, and is formed between the left crankcase 3L and the generator cover 41. The generator cover 41 is fixed to the left crankcase 3L via a bolt 42. The left end portion of the crankshaft 10 penetrates the left crankcase 3L and protrudes into the generator chamber 40. The internal space of the generator chamber 40 and the internal space of the crank chamber 11 communicate with each other via cast-through holes 71, 72, 73 (FIG. 1) formed in the left crankcase 3L at the time of casting.
[0026]
A generator stator 43 is fixed inside the generator cover 41. A generator rotor 44 having a shape surrounding the outer periphery of the generator stator 43 is attached to a protruding portion of the crankshaft 10 into the generator chamber 40. An AC generator 45 is formed by the generator stator 43 and the generator rotor 44, and power is generated when the generator rotor 44 rotates together with the crankshaft 10.
[0027]
A starter motor (not shown) is provided between the two cylinders. The rotation shaft of the starter motor protrudes into the generator chamber 40, and a starter motor pinion 46 is fixed to the protruding portion of the rotation shaft in the generator chamber 40 as shown in FIG. A starting gear 47 is fixed to a portion of the crankshaft 10 in the generator chamber 40. Further, a gear train 48 is interposed between the starter motor pinion 46 and the starting gear 47. When the starter motor rotates to start the internal combustion engine, the crankshaft 10 is given a starting rotation through the starter motor pinion 46, the gear train 48, and the starting gear 47.
[0028]
Next, the outline of the gas-liquid separation chamber 50 of the breather apparatus will be described with reference to FIG. The gas-liquid separation chamber 50 of the breather device is provided on the side of the cylinder block 4 and above the generator chamber 40. The gas-liquid separation chamber 50 has a plurality of baffle plates arranged therein to form a maze-like gas passage. Distribution ports 51 and 52 are provided in the lower part of the gas-liquid separation chamber 50. The interior of the gas-liquid separation chamber 50 communicates with the interior of the generator chamber 40 via the flow ports 51 and 52 and the communication holes 74 and 75 provided in the upper portion of the generator chamber 40. A gas outflow pipe 53 is provided in the upper part of the gas-liquid separation chamber 50.
[0029]
Next, the details of the position and structure of the gas-liquid separation chamber 50 will be described. 3 is a view of the cylinder block 4 as viewed from above, FIG. 4 is a view of the cross section of the cylinder block 4 as viewed from the rear (IV-IV sectional view of FIG. 3), and FIG. 5 is a view of the cylinder block 4 as viewed from below. FIG. In these figures, the arrow F ₁ Indicates the front in the direction perpendicular to the cylinder axis of the first cylinder, and the arrow U ₁ Indicates the upper side in the direction parallel to the cylinder axis of the first cylinder. Note that the arrow F in FIG. ₁ Is the same.
[0030]
A cylinder hole 7 is provided in the center of the cylinder block 4, and a water jacket 54 is provided in the wall around the cylinder hole 7 (FIGS. 3 and 4). A cooling water outlet pipe 55 is provided (FIGS. 3 and 5). In FIG. 4, a cylinder extension 56 that is inserted into the crankcase 3 is provided at the lower portion of the cylinder block 4. A cylinder liner 57 is provided on the inner surface of the cylinder hole 7 (FIGS. 4 and 5). The upper surface of the cylinder block 4 has a mating surface 58 with the cylinder head 5, and the lower surface of the cylinder block 4 has a mating surface 59 with the crankcase 3. 3 and 5, the mating surfaces 58 and 59 are shown with dots. A cam chain chamber 60 is provided integrally with the cylinder block 4 on the right side of the cylinder block 4. On the opposite side, that is, on the left side of the cylinder block 4, the air of the breather device is integrated with the cylinder block 4. A main body 61 of the liquid separation chamber 50 is provided.
[0031]
FIG. 6 is a view of the cylinder block 4 as viewed from the left, and shows the front of the gas-liquid separation chamber main body 61. 7 and 8 are views of the gas-liquid separation chamber lid member 62 attached to the gas-liquid separation chamber main body 61. FIG. 7 is a view seen from the front side, and FIG. 8 is a view seen from the inside. 6 and 8, the mating surfaces of the main body 61 and the lid member 62 are indicated by dots. The gas-liquid separation chamber body 61 and the gas-liquid separation chamber lid member 62 are integrally coupled to form one gas-liquid separation chamber 50.
[0032]
In FIG. 6, a baffle plate 63 </ b> A and a baffle plate 64 </ b> A are integrally formed with the cylinder block 4 in the gas-liquid separation chamber main body 61. A gas passage 65 is provided in the baffle plate 64A. In addition, flow holes 51 and 52 are provided in the lower part of the main body 61. The interior of the gas-liquid separation chamber 50 communicates with a communication chamber 66 provided in the lower part of the gas-liquid separation chamber main body 61 through the flow holes 51 and 52 (FIGS. 4, 5, and 6). FIG. 4 shows a cross section of the communication chamber 66. The downward opening 66a of the communication chamber 66 faces the generator chamber 40 through a mating surface between the cylinder block 4 and the left crankcase 3L.
[0033]
In FIG. 8, a baffle plate 63 </ b> B and a baffle plate 64 </ b> B are formed integrally with the lid member 62 on the gas-liquid separation chamber lid member 62. A gas passage 67 is provided in the baffle plate 63B. A gas outflow pipe 53 is attached to the upper part of the lid member 62. The gas outflow pipe 53 is connected to a clean side of an air cleaner box (not shown) by a hose.
[0034]
The gas-liquid separation chamber main body 61 and the gas-liquid separation chamber lid member 62 are inserted into the four female screw holes 68 of the main body 61 through four bolts inserted through the four bolt insertion holes 69 of the lid member. The gas-liquid separation chamber 50 is formed by being integrally joined by screwing.
[0035]
FIG. 9 is a view of the left crankcase 3L as viewed from above. The mating surface 77 with the cylinder block 4 is dotted. A communication hole 74 to the generator chamber 40 at a position corresponding to a downward opening 66a (FIGS. 4 and 5) of the communication chamber 66 provided adjacent to the gas-liquid separation chamber 50 on the upper surface of the left crankcase 3L. , 75 are provided. The positions of the communication holes 74 and 75 are also shown in FIG.
[0036]
In FIG. 1, an oil protection plate 79 formed integrally with the left crankcase 3 </ b> L is provided below the communication holes 74 and 75. Although the generator chamber 40 is a place with little oil mist, oil splashes generated by the rotation of the generator rotor 44 are prevented from flying toward the communication holes 74 and 75, and return oil from the gas-liquid separation chamber 50 is prevented. Is to prevent the liquid from dropping directly onto the generator rotor 44.
[0037]
FIG. 10 is a cross-sectional view for explaining the flow of gas and oil in the gas-liquid separation chamber 50. The gas outflow pipe 53, the gas passage 65, and the gas passage 66 are on mutually different cross sections, and originally cannot be represented in a single sectional view, but in order to explain the flow of gas and oil in an easy-to-understand manner, FIG. 4 is a diagram that expresses a single sectional view by combining partial views of different sections. In this figure, the internal combustion engine 1 is shown tilted so as to have a posture when mounted on a vehicle. Arrow F in this figure ₀ Is the front of the vehicle, arrow U ₀ Indicates the upper part of the vehicle. The thick broken line in the figure indicates the gas flow, and the thick solid line indicates the oil flow.
[0038]
When the gas including blow-by gas and oil mist flows into the first chamber 50 a of the gas-liquid separation chamber 50 through the flow holes 51 and 52, next flows into the second chamber 50 b through the gas passage 67. At this time, the gas collides with the baffle plate 64, and oil in the gas adheres to the lower surface of the baffle plate 64. The gas further flows into the third chamber 50c through the gas passage 65. At this time, the gas collides with the ceiling portion of the third chamber 50c, and oil in the gas adheres to the lower surface of the ceiling portion. The gas from which the oil component has been separated and removed is supplied to the clean side of the air cleaner box via a gas outlet pipe 53 and a hose (not shown) connected to the gas outlet pipe 53, and then to the combustion chamber of the internal combustion engine via the intake port. Sent and burned.
[0039]
The oil adhering to the lower surface of the baffle plate 64 and the ceiling portion of the third chamber is dripped as a soot and flows down the upper surface of the baffle plates 64 and 63 and is discharged from the lower flow hole 52. This oil returns to the crank chamber 11 through the generator chamber 40. The above description of the gas flow is a simplified description of the operation. Actually, the gas flows in a complicated manner in the gas-liquid separation chamber 50, so that the oil is attached to and collected in other parts than the above.
[0040]
The breather apparatus of the present invention has the above-described structure. Next, the operation will be described. When the internal combustion engine 1 is operated, blow-by gas flows out from the combustion chamber 17 into the crank chamber 11 through the gap between the piston 8 and the inner wall surface of the cylinder liner 57 in the compression combustion stroke. Further, the lubricating oil in the crank chamber 11 is vigorously stirred by the high speed rotation of the crankshaft 10 and the power transmission gears 30 and 31 to become oil mist, which fills the crank chamber 11.
[0041]
When the piston enters the downward stroke, the air in the crank chamber 11 including blow-by gas and oil mist is discharged to the generator chamber 40 through the cast through holes 71, 72, 73 (FIG. 1) of the left crankcase 3L. Next, the communication holes 74 and 75 (FIGS. 1 and 9) of the left crankcase 3L, the communication chamber 66 (FIGS. 4, 5 and 6) of the cylinder block 4 and the flow holes 51 and 52 (FIGS. 1 and 4). 6), the gas-liquid separation chamber is entered.
[0042]
The gas-liquid separation chamber 50 is a chamber in which the inside is partitioned by baffle plates 63 and 64 to form a labyrinth-like flow path, where air containing blowby gas and oil components are separated, and air containing blowby gas is The gas-liquid separation chamber-like part is led to the clean side of the air cleaner box through the gas outflow pipe 53 (FIGS. 1, 7 and 8), and is sucked together with fresh air into the combustion chamber through the intake port of the internal combustion engine. To be burned.
[0043]
The separated oil component flows down in the gas-liquid separation chamber 50, and of the two circulation holes 51, 52, the circulation hole 52, the communication chamber 66, which is mainly in a low position in the vehicle-mounted state of the internal combustion engine, Then, it returns to the generator chamber 40 through the communication hole 75 at the lower position, and further enters the crank chamber 11 through the cast through hole 73 at the lowest position among the three cast through holes 71, 72, 73. Return to.
[0044]
The internal combustion engine 1 of the present embodiment employs a dry sump type lubrication system, and the oil returned to the crank chamber 11 is provided below the generator chamber 40 of FIG. 1 by an oil pump (not shown). It is sucked out from the oil suction passage 78 and sent to an oil tank (not shown).
[0045]
When the piston enters the ascending stroke, the inside of the crank chamber 11 is depressurized, so that the air on the clean side of the air cleaner box is not shown in the drawing, the hose, the gas outflow pipe 53, the gas-liquid separation chamber 50, the flow holes 51, 52. , The communication chamber 66, the communication holes 74, 75, the generator chamber 40, and the cast through holes 71, 72, 73 are supplied to the crank chamber 11.
[0046]
Since the breather apparatus according to the present embodiment is configured and operates as described above, the following effects can be obtained. First, the breather unit's gas passage is an independent gas passage away from the cam chain chamber, so there is no suction of return oil from the cylinder head or oil flowing through the valve system, and the amount of oil mist suction is reduced. There are few breather devices. In addition, in the internal combustion engine in which a push rod chamber is provided instead of the cam chain in the cam chain chamber and the intake and exhaust valves are driven by the push rod, similarly, an independent dedicated gas passage away from the push rod chamber is used. Therefore, it is possible to provide a breather device that does not suck oil and has a small oil mist suction amount.
[0047]
Next, since the gas-liquid separation chamber is provided on the side of the cylinder block, the gas-liquid separation chamber can be installed without increasing the height and width of the internal combustion engine, and the gas-liquid separation chamber can be provided from the outside of the internal combustion engine. Since it can be disassembled, maintenance is easy.
[0048]
In addition, a generator chamber with less splashed oil is interposed between the gas-liquid separation chamber and the crank chamber, and the inlet of the gas-liquid separation chamber communicates with the generator chamber. Inflow can be reduced, and effective gas-liquid separation is possible.
[Brief description of the drawings]
FIG. 1 is a side view (partially with a longitudinal section) of an internal combustion engine 1 on which a breather device of the present invention is mounted.
FIG. 2 is a cross-sectional view of the internal combustion engine as viewed from above (II-II cross-sectional view of FIG. 1).
FIG. 3 is a view of a cylinder block 4 as viewed from above.
4 is a rear cross-sectional view of the cylinder block 4 (IV-IV cross-sectional view of FIG. 3).
FIG. 5 is a view of the cylinder block 4 as viewed from below.
6 is a view of the cylinder block 4 as viewed from the left, and shows the front of the gas-liquid separation chamber main body 61. FIG.
FIG. 7 is a view of the gas-liquid separation chamber lid member 62, as viewed from the front side.
FIG. 8 is a view of the gas-liquid separation chamber lid member 62, as viewed from the inside.
FIG. 9 is a view of the left crankcase 3L as viewed from above.
10 is an explanatory diagram of gas and oil flows in the gas-liquid separation chamber 50. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 4 stroke cycle V type 2 cylinder internal combustion engine, 2A ... 1st cylinder, 2B ... 2nd cylinder, 3 ... Crankcase, 3L ... Left crankcase, 3R ... Right crankcase, 4 ... Cylinder block, 4a ... Cooling water Passage, 5 ... Cylinder head, 6 ... Cylinder head cover, 7 ... Cylinder hole, 8 ... Piston, 9 ... Connecting rod, 9x ... Large end of connecting rod of the first cylinder, 10 ... Crank shaft, 11 ... Crank chamber, 13 ... Cam Shaft, 13a ... intake cam, 13b ... exhaust cam, 14 ... drive sprocket, 15 ... driven sprocket, 16 ... cam chain, 17 ... combustion chamber, 18 ... spark plug, 20L ... left transmission case, 20R ... right transmission case 21 ... gear cover, 22 ... bolt, 23 ... bolt, 24 ... bolt, 25 ... drive pulley shaft, 26 ... driven pulley shaft, 27 ... intermediate shaft, 2 DESCRIPTION OF SYMBOLS ... Output shaft, 30 ... Drive gear, 31 ... Drive gear, 32 ... Drive pulley, 33 ... Drive pulley, 34 ... V belt, 35 ... Starting clutch, 36 ... Small gear, 37 ... Intermediate gear, 38 ... Output shaft gear, DESCRIPTION OF SYMBOLS 40 ... Generator room, 41 ... Generator cover, 42 ... Bolt, 43 ... Generator stator, 44 ... Generator rotor, 45 ... Alternator, 46 ... Starter motor pinion, 47 ... Starting gear, 48 ... Gear 50, gas-liquid separation chamber, 50a, first chamber, 50b, second chamber, 50c, third chamber, 51, flow hole, 52, flow hole, 53, gas outflow pipe, 54, water jacket, 55 ... Cooling water outlet pipe, 56 ... cylinder extension, 57 ... cylinder liner, 58 ... mating surface with cylinder head 5, 59 ... mating surface with crankcase 3, 60 ... cam chain chamber, 61 ... gas-liquid separation chamber Body part, 62 Gas-liquid separation chamber lid member, 63 ... baffle plate, 63A ... baffle plate, 63B ... baffle plate, 64 ... baffle plate, 64A ... baffle plate, 64B ... baffle plate, 65 ... gas passage, 66 ... generator chamber 40 and air Communication chamber with the liquid separation chamber 50, 66a ... Opening of communication chamber, 67 ... Gas passage, 68 ... Female screw hole, 69 ... Bolt insertion hole, 71 ... Cast-through hole, 72 ... Cast-through hole, 73 ... Punched through hole, 74 ... Communication hole, 75 ... Communication hole, 76 ... Splash protection plate, 77 ... Mating surface with cylinder block 4, 78 ... Oil suction passage, 79 ... Oil protection plate.

Claims (3)

In a breather device for a four-stroke cycle internal combustion engine,
A gas-liquid separation chamber for separating oil in the gas discharged from the crank chamber is provided on the side of the cylinder block or cylinder head opposite to the cam chain chamber or push rod chamber with respect to the cylinder hole. A breather device for an internal combustion engine. The gas-liquid separation chamber comprises a gas-liquid separation chamber main body integrally provided on the side of the cylinder block or cylinder head, and a gas-liquid separation chamber lid member attached to the main body, and the gas-liquid separation The breather device for an internal combustion engine according to claim 1, wherein the chamber lid member is attached from a side of the cylinder block or the cylinder head. In a breather device for a four-stroke cycle internal combustion engine comprising a generator chamber that houses an AC generator driven by the crankshaft at the end of the crankshaft,
A gas-liquid separation chamber for separating oil in the gas discharged from the crank chamber is provided on a side of the cylinder block or the cylinder head and above the generator chamber, and the crank chamber is in communication with the generator chamber; and A breather device for an internal combustion engine, characterized in that a generator chamber communicates with an inlet side of the gas-liquid separation chamber.

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