JP2023136175A - internal combustion engine - Google Patents

Abstract

To efficiently discharge engine oil supplied to a generator chamber to the outside of a crank chamber in an internal combustion engine in which the engine oil supplied to the generator chamber is returned to an oil reservoir via the crank chamber.SOLUTION: An internal combustion engine includes a crankcase forming a sealed crank chamber 23 for storing a crankshaft, and a plurality of scavenge pumps 51L sucking engine oil flowing down from the sealed crank chamber 23 and returning it to an oil pan. An ACG chamber 28 for storing an ACG 17 is formed on one side (left side) in an axial direction of the crankshaft in the crankcase, a communication portion 45 for allowing the ACG chamber 28 to communicate with the sealed crank chamber 23 is provided in a partition wall 25a partitioning the ACG chamber 28 and the sealed crank chamber 23, and the communication portion 45 guides the engine oil flowing into the ACG chamber 28 to an oil suction port 72aL of the left scavenge pump 51L opened into the sealed crank chamber 23.SELECTED DRAWING: Figure 8

Description

The present invention relates to internal combustion engines.

Patent Document 1 discloses that a through hole is formed in a cylinder block of an engine to communicate a cam chamber and a crank chamber, and the through hole is used as a blow-by gas passage or the like.

Japanese Patent Application Publication No. 2018-193972

As in the above-mentioned prior art, it is conceivable to use the space as an engine oil passage for the purpose of communicating the spaces inside the engine. For example, it is conceivable that an oil passage for returning engine oil supplied to the generator chamber on one side of the crankcase to the crank chamber is formed by a communication portion that communicates the generator chamber and the crank chamber. The engine oil returned to the crank chamber is sucked into, for example, a scavenge pump and returned to an oil pan (oil reservoir).
It is desirable that the engine oil supplied to the generator room be efficiently discharged to the outside of the crank room. That is, since the generator rotates at the same speed as the crankshaft, friction due to oil stirring is large, and it is desirable to prevent oil from stagnation in the generator room and reduce oil resistance.

Therefore, an object of the present invention is to enable the engine oil supplied to the generator room to be efficiently discharged to the outside of the crank room in an internal combustion engine in which the engine oil supplied to the generator room is returned to the oil reservoir via the crank room. .

As a means for solving the above problem, the invention described in claim 1 provides a crank case (20) forming a crank chamber (23) for accommodating a crankshaft (11), and an engine oil flowing down from the crank chamber (23). In an internal combustion engine equipped with a scavenge pump (51L, 51R) that sucks in oil and returns it to the oil storage part (40), a power generating unit is provided on one side of the crankshaft (11) in the axial direction of the crankcase (20). A generator room (28) that accommodates the engine (17) is formed, and a partition wall (25a) that partitions the generator room (28) and the crank room (23) has a partition wall (25a) that separates the generator room (28) and the crank room (23). A communication part (45) is provided that communicates with the crank chamber (23), and the communication part (45) opens the engine oil that has flowed into the generator room (28) into the crank room (23). An internal combustion engine is provided that guides the oil to the oil suction port (72aL) of the scavenge pump (51L).
According to this configuration, the engine oil in the crank chamber is discharged to the outside of the crank chamber by the scavenge pump, and the engine oil that has flowed into the generator chamber is passed through the at least one scavenge pump opening into the crank chamber through the communication part provided in the partition wall. directly into the pump suction port. Therefore, compared to a configuration in which the communication portion guides the engine oil to a portion of the crank chamber that avoids the suction port, the engine oil can be quickly discharged to the outside of the crank chamber. Therefore, the amount of oil sucked in and the amount of oil discharged by the scavenge pump can be easily increased, and the oil resistance generated within the crankcase (resistance during power transmission by the crankshaft) can be reduced.

In the invention described in claim 2, the communication portion (45) is arranged above the oil suction port (72aL).
According to this configuration, the engine oil that has passed through the communication part directly enters the oil suction port of the scavenge pump and is immediately discharged to the outside of the crankcase by the scavenge pump, so that the engine oil in the generator compartment is smoothly transferred to the outside of the crankcase. can be discharged. Therefore, the resistance (oil resistance) during power transmission by the crankshaft can be reduced.

In the invention described in claim 3, the communication portion (45) is arranged above the pump rotor (53L) of the scavenge pump (51L).
According to this configuration, the engine oil that has passed through the communication part is directly sucked into the pump rotor of the scavenge pump, and is immediately guided to the outside of the crankcase by the scavenge pump, so that the engine oil in the generator compartment can be smoothly transferred to the outside of the crankcase. Can be discharged. Therefore, the resistance (oil resistance) during power transmission by the crankshaft can be reduced.

In the invention described in claim 4, the communication portion (45) is arranged below the rotation orbit (R) of the crankshaft (11).
According to this configuration, the engine oil flowing into the crank chamber from the communication portion is prevented from being rolled up by the crankshaft, so that the engine oil in the generator chamber can be smoothly discharged to the outside of the crank chamber. Therefore, the resistance (oil resistance) during power transmission by the crankshaft can be reduced.

The invention described in claim 5 is provided with a crank chamber oil separator (86) in the crank chamber (23) for scraping off stirring oil on the outer peripheral side of the crankshaft (11), and the communication portion (45) is , is arranged below the crank chamber oil separator (86).
According to this configuration, the engine oil flowing through the communication path and the engine oil scraped off by the crank chamber oil separator in the crank chamber are less likely to interfere with each other. Therefore, each engine oil in the generator chamber and the crank chamber can be smoothly discharged to the outside of the crank chamber. Therefore, the resistance (oil resistance) during power transmission by the crankshaft can be reduced.

In the invention described in claim 6, the lower wall portion (29a) of the generator room (28) is inclined downwardly toward the rear, and the communication portion (45) is arranged at the lower rear of the generator room (28). It is located.
According to this configuration, engine oil dripping onto the lower wall of the generator room is naturally guided toward the communication section at the rear lower part of the generator room, so the engine oil flowing into the generator room is concentrated. It becomes easier. Therefore, the engine oil in the generator chamber can be smoothly discharged to the outside of the crank chamber. Therefore, the resistance (oil resistance) during power transmission by the crankshaft can be reduced.

According to the present invention, in an internal combustion engine in which the engine oil supplied to the generator chamber is returned to the oil storage portion via the crank chamber, the engine oil supplied to the generator chamber can be efficiently discharged to the outside of the crank chamber.

FIG. 1 is a left side view of a motorcycle in an embodiment of the present invention. FIG. 2 is a right side view of the engine of the motorcycle, showing an outline of the internal configuration. FIG. 3 is a right side view including a partial cross section of the main parts of the engine. It is a top view of the said pump unit. 5 is a sectional view taken along line VV in FIG. 4. FIG. FIG. 3 is a left side view of the ACG chamber of the engine. It is a right side view of the ACG cover which covers the above-mentioned ACG chamber, and shows the ACG chamber oil separator of the first embodiment. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7; 8 is an enlarged view of the main part of FIG. 7, showing the action of the ACG chamber oil separator of the first embodiment. FIG. It is a right side view of the ACG chamber oil separator removed from FIG. 9 in the first lowered state. It is a perspective view of the ACG chamber oil separator of a first embodiment. 12 is a perspective view of the ACG chamber oil separator seen from a different direction from FIG. 11. FIG. It is a left side view of the above-mentioned ACG chamber, and shows an oil separator of a second embodiment. 14 is a left side view with the ACG removed from FIG. 13. FIG. FIG. 15 is a left side view of FIG. 14 with the ACG chamber oil separator removed. 14 is a sectional view taken along the line XVI-XVI in FIG. 13. FIG. It is a perspective view of the ACG chamber oil separator of a second embodiment. 18 is a perspective view of the ACG chamber oil separator seen from a different direction from FIG. 17. FIG.

Embodiments of the present invention will be described below with reference to the drawings. Note that the directions such as front, rear, left, and right in the following description are the same as the directions of the vehicle described below unless otherwise specified. In addition, arrow FR indicating the front of the vehicle, arrow LH indicating the left side of the vehicle, and arrow UP indicating the upward direction of the vehicle are shown at appropriate locations in the drawing used in the following explanation. In the specifications and drawings of the embodiments, "L" and "R" may be omitted from the symbols of a pair of left and right components to be collectively referred to.

<Entire vehicle>
As shown in FIG. 1, a motorcycle (saddle-type vehicle) 1 according to the embodiment includes a front wheel 2, a rear wheel 3, a front fork 4 that supports the front wheel 2, a swing arm 5 that supports the rear wheel 3, and a front fork 4 that supports the front wheel 2. The vehicle includes a vehicle body frame 6 that supports a front fork 4 and a swing arm 5, and an engine (internal combustion engine, prime mover) 7 supported by the vehicle body frame 6.

Referring also to FIG. 2, the engine 7 of the embodiment is a V-type four-cylinder engine in which the rotation center axis (crank axis) C1 of the crankshaft 11 is aligned in the vehicle width direction (vehicle left-right direction). The engine 7 includes a crankcase 20, a forward-tilting cylinder 31, and a backward-tilting cylinder 32.
The crankcase 20 rotatably supports the crankshaft 11. Arrow F in the figure indicates the direction of rotation of the crankshaft 11 during engine operation. The crankcase 20 accommodates the crankshaft 11 at the front and the transmission 16 at the rear.

The crankcase 20 includes a crank chamber forming section 21 that accommodates the crank pin 12 of the crankshaft 11 and a crank web (crank arm) 13, and a mission case section 26 that accommodates the transmission 16.
An oil pan 40 is attached to the lower part of the crankcase 20 from below. A pump unit 50, which will be described in detail later, is attached to the lower part of the crank chamber forming portion 21 from below. The oil pan 40 is an example of an oil reservoir. An oil tank separate from the engine 7 may be provided as the oil storage section.

The forward tilting cylinder 31 and the backward tilting cylinder 32 are provided above the front part of the crankcase 20. The forward tilting cylinder 31 stands up diagonally upward and forward, and the backward tilting cylinder 32 stands up diagonally upward and backward. A piston 14 is inserted into each of the forward-tilting cylinder 31 and the backward-tilting cylinder 32, respectively.

Each piston 14 is connected to a crank pin 12 of the crankshaft 11 via a connecting rod 15, respectively. The reciprocating motion of the piston 14 is converted into rotational motion of the crankshaft 11 via the connecting rod 15. The rotational driving force of the crankshaft 11 is transmitted to the transmission 16 via a clutch (not shown), and after appropriate gear changes are transmitted to the rear wheels 3 via, for example, a chain-type power transmission mechanism.

<Sealed crank chamber>
Referring to FIGS. 2 and 5, the crank chamber forming portion 21 forms a pair of closed crank chambers (crank chambers) 23 that are independent from each other. The pair of sealed crank chambers 23 are lined up in the vehicle width direction. Each sealed crank chamber 23 communicates with either the left or right cylinder interior of the forward-tilting cylinder 31 and the backward-tilting cylinder 32, respectively. Each sealed crank chamber 23 is partitioned from each space within the mission case portion 26 and the oil pan 40 by a partition wall within the crankcase 20 .

By forming a sealed crank chamber 23 and forcing the internal pressure of the crankcase 20 to negative pressure using scavenge pumps 51L and 51R, which will be described later, pumping loss caused by piston movement is reduced. By discharging excess engine oil in the sealed crank chamber 23, oil agitation by the crankshaft 11 is reduced and friction loss is suppressed. Each of the pair of crank pins 12 of the crankshaft 11 , a pair of crank webs 13 that support each crank pin 12 , and a pair of connecting rods 15 connected to each crank pin 12 are arranged in each sealed crank chamber 23 . has been done.

Although the engine 7 of the embodiment uses the scavenge pumps 51L and 51R to create a negative pressure in the sealed crank chamber 23, the present invention is not limited to this configuration. For example, the engine may be a dry sump engine in which the oil in the crank chamber is discharged by a scavenge pump without the need to seal the crank chamber (negative pressure). A wet sump engine may also be used in which engine oil is stored in an oil pan below the engine without using a scavenge pump.

Referring to FIGS. 4 and 5, a pair of openings 23a are formed in the lower partition wall 22 that partitions the lower part of the crank chamber forming portion 21 to open each closed crank chamber 23 downward. Each opening 23a in the lower partition wall 22 is connected to and communicates with each oil suction port 72aL, 72aR of a pair of scavenge pumps 51L, 51R in the pump unit 50 from below. In the figure, reference numeral 23c indicates a pump mounting surface on the lower partition wall 22 of the crank chamber forming portion 21 to which the pump unit 50 is attached, and reference numeral 50c indicates an attached surface of the pump unit 50 that faces (contacts) the pump mounting surface 23c. Each is shown below. The pump mounting surface 23c and the mounting surface 50c are arranged so as to be inclined backwardly when the engine 7 is mounted on the vehicle, for example.

Referring to FIGS. 2 and 3, the oil pan 40 is attached below the crankcase 20. The oil pan 40 is provided so as to protrude downward from a substantially horizontal lower end surface of the crankcase 20. The oil pan 40 is formed into a container shape that opens upward. The upper end opening of the oil pan 40 is coupled to the lower end opening of the crankcase 20 by coming into contact with it from below.

An oil storage space 41 is formed within the oil pan 40 to store engine oil. The oil storage space 41 communicates with the lower space of the crankcase 20 (the space below the lower partition wall 22). A pump unit 50 is arranged in the lower space of the crankcase 20.

<Pump unit>
Referring to FIGS. 4 and 5, the pump unit 50 is attached to the lower surface side of the lower partition wall 22 of the crank chamber forming portion 21. The pump unit 50 has a plurality of oil pumps, which are internal gear pumps with trochoidal teeth, arranged along the vehicle width direction (crankshaft direction). The pump unit 50 includes, in order from left to right, a left scavenge pump 51L, a feed pump 51C, and a right scavenge pump 51R.

The left scavenge pump 51L, feed pump 51C, and right scavenge pump 51R each include rotors 53L, 53C, and 53R inside housings (pump housings) 52L, 52C, and 52R.

Each of the rotors 53L, 53C, and 53R includes an annular outer rotor 54 that is rotatably provided in a cylindrical space within the corresponding housing 52L, 52C, and 52R, but cannot be moved in parallel; The inner rotor 55 is rotatably provided around an axis eccentric with respect to the inner rotor 54. The outer rotor 54 has internal teeth, and the inner rotor 55 has more external teeth than internal teeth. The outer rotor 54 and the inner rotor 55 form an oil chamber 56 between the inner teeth and the outer teeth.

When the drive shaft 66 rotates in conjunction with the rotation of the crankshaft 11, the outer rotor 54 and the inner rotor 55 rotate while changing the volume of the oil chamber 56, forcing the fluid in the oil chamber 56 to the downstream side.
The pump unit 50 includes a single pump body 60 and a single drive shaft 66 that are shared by the left scavenge pump 51L, feed pump 51C, and right scavenge pump 51R.

The pump body 60 includes left and right divided bodies 61 and 63 arranged on the left and right outer sides, respectively, and a first intermediate divided body 62 and a second intermediate divided body 64 arranged between the left and right divided bodies 61 and 63. . The plurality of divided bodies 61 to 64 are arranged in this order from the left: left divided body 61, first intermediate divided body 62, second intermediate divided body 64, and right divided body 63. The plurality of divided bodies 61 to 64 are integrally fastened to each other by a plurality of connecting bolts extending in the vehicle width direction. By dividing the pump body 60 into a plurality of divided bodies 61 to 64 in the vehicle width direction, the pump rotor 57 (outer rotor 54 and inner rotor 55) of each pump 51L, 51C, 51R can be assembled. The pump rotor 57 has a configuration corresponding to the rotor 53L, 53C, 53R of each pump 51L, 51C, 51R. "Middle" in the description of the embodiments means not only the center between both ends of the object but also the inner range between both ends of the object.

The drive shaft 66 is provided so as to be rotatable around an axis (pump rotation center axis) C2 along the vehicle width direction. The drive shaft 66 has left and right end portions protruding to the left and right outer sides of the pump body 60 . For example, the input gear 36 to which the rotation of the crankshaft 11 is transmitted is attached to the right end of the drive shaft 66 so as to be rotatable therewith. For example, an output gear (not shown) that transmits rotation to other auxiliary equipment such as a water pump (not shown) is rotatably attached to the left end of the drive shaft 66. The drive shaft 66 coaxially supports each inner rotor 55 of the left scavenge pump 51L, feed pump 51C, and right scavenge pump 51R.

<Scavenge pump>
Referring to FIGS. 4 and 5, each housing 52L, 52R of the left scavenge pump 51L and right scavenge pump 51R has a rotor housing section 70 (FIG. 6) that accommodates the respective pump rotor 57 (outer rotor 54 and inner rotor 55). ), and suction ports 71L, 71R and a discharge port (not shown) that are continuous with the rotor accommodating portion 70 and are independent from each other.

Each of the rotor housing portions 70 of the left scavenge pump 51L and the right scavenge pump 51R forms a cylindrical housing space that follows the outer shape of each pump rotor 57. Each suction port 71L, 71R extends below each oil suction port 72aL, 72aR. The rotor accommodating portions 70 of the left scavenge pump 51L and the right scavenge pump 51R are provided so as to protrude below each suction port 71L, 71R. A pair of openings 23a are formed in the pump mounting surface 23c of the lower partition wall 22 and communicate with the respective oil suction ports 72aL and 72aR.

The upper end surface of each suction port 71L, 71R (the surface forming each oil suction port 72aL, 72aR) is a mounting surface 50c relative to the pump mounting surface 23c. Each oil suction port 72aL, 72aR has a substantially rectangular shape in plan view, and is arranged with front and rear sides along the vehicle width direction. Each of the oil suction ports 72aL and 72aR on the mounting surface 50c communicates with a pair of openings 23a formed in the lower partition wall 22 of the crank chamber forming portion 21, respectively. Each suction port 71L, 71R forms an oil flow path extending from each oil suction port 72aL, 72aR to oil chamber 56 of pump rotor 57, respectively. The oil flow path of each suction port 71L, 71R is connected to the corresponding sealed crank chamber 23 through each oil suction port 72aL, 72aR and each opening 23a.

Each of the discharge ports of the left scavenge pump 51L and the right scavenge pump 51R has an oil discharge port on the outside in the vehicle width direction of the corresponding rotor accommodating portion 70 (both not shown).
A crank chamber oil separator 86 is disposed on the upper surface side of the lower partition wall 22 (on the closed crank chamber 23 side) for scraping off engine oil that circulates along the crankshaft 11. The crank chamber oil separator 86 will be described in detail later.

<Feed pump>
Referring to FIGS. 3 to 5, the housing 52C of the feed pump 51C includes a rotor accommodating part 70 that accommodates the pump rotor 57 (outer rotor 54 and inner rotor 55), and a rotor accommodating part 70 that extends below the rotor accommodating part 70 and connects to the strainer 77. It includes a suction pipe 75 to be connected, and a discharge pipe 76 that extends downward parallel to the suction pipe 75, bends forward, and is connected to an oil line extending to each part of the engine 7. The rotor accommodating portion 70 of the feed pump 51C is sandwiched between the rotor accommodating portions 70 of the left and right scavenge pumps 51L, 51R in the left-right direction, and overlaps with the rotor accommodating portions 70 of the left and right scavenge pumps 51L, 51R in side view. It is provided.

The strainer 77 extends below the suction pipe 75 and is immersed in engine oil stored in the oil pan 40 . The feed pump 51C sucks the engine oil in the oil pan 40 through the strainer 77 and pumps this engine oil from the discharge pipe 76 to the oil line.

<Reed valve>
Referring to FIGS. 4 and 5, the pump unit 50 includes a pair of left and right reed valves 90L and 90R. The left and right reed valves 90L and 90R are provided corresponding to the sealed crank chambers 23 on the same left and right sides, respectively. The left reed valve 90L is provided at the suction port 71L of the left scavenge pump 51L, and the right reed valve 90R is provided at the suction port 71R of the right scavenge pump 51R. The left and right reed valves 90L, 90R allow engine oil to flow in a direction from each suction port 71L, 71R toward the oil storage space 41 outside the pump unit 50, and restrict flow in the opposite direction.

The left and right reed valves 90L, 90R are provided in a communication portion 92 that communicates the inside and outside of each suction port 71L, 71R. The left and right reed valves 90L and 90R include a valve body 93 that opens and closes the communication portion 92 according to the internal pressure of the corresponding closed crank chamber 23, and a stopper 94 that restricts movement of the valve body 93 when the valve is opened. .

The communication portion 92 penetrates the front lower wall 71a of each of the suction ports 71L, 71R in the normal direction (front-to-back direction inclined downward). The communication portion 92 communicates the inside of each suction port 71L, 71R (inside the sealed crank chamber 23) with the oil storage space 41 in the oil pan 40.

The upper side portion (one side edge portion) of the valve body 93 is fastened and fixed to a valve fastening portion 95 connected to the upper side of the front lower wall 71a by a pair of left and right valve fixing bolts. The lower side (the other side edge) of the valve body 93 is a free end that can be separated from the pump body 60. The valve body 93 can be elastically deformed so as to separate the lower side from the front lower wall 71a as the internal pressure of the closed crank chamber 23 increases. This allows communication between the closed crank chamber 23 and the oil storage space 41 by opening the communication portion 92.

The valve fastening portion 95 projects upwardly from the upper end of the front lower wall 71a along the slope of the front lower wall 71a. The valve fastening portion 95 protrudes (overhangs) above the pump mounting surface 23c (on the side opposite to the pump main body including the housing and rotor). The valve fastening portion 95 protrudes to the inside of the crankcase 20 (the side closer to the crankshaft 11) beyond the pump mounting surface 23c.
A space bulging portion 24 is formed in the lower partition wall 22 of the crank chamber forming portion 21. The space bulging portion 24 bulges out the oil storage space 41 in the oil pan 40 toward the inside of the crankcase 20 rather than the pump mounting surface 23c. A valve fastening portion 95 is arranged inside this space bulge portion 24 .

The direction in which each of the reed valves 90L and 90R opens (the direction of the valve opening) is diagonally backward and downward along the front lower wall 71a. A rotor accommodating portion 70 that protrudes forward and downward at the front end of the pump body 60 is arranged in the direction in which each reed valve 90L, 90R opens. When each reed valve 90L, 90R opens and engine oil is discharged from the sealed crank chamber 23 side into the oil storage space 41, this engine oil hits the outer surface of the rotor housing part 70 and is contained in the engine oil. Air separation (gas-liquid separation) is achieved.

<Crank chamber oil separator>
Referring to FIG. 5, the engine 7 according to the embodiment includes a crank chamber oil separator 86 for scraping off engine oil that circulates around the crankshaft 11 (particularly the crank web 13 having a large rotation radius). The crank chamber oil separator 86 is supported and fixed to the crankcase 20, for example. The crankcase 20 includes a space bulge 24 adjacent to the front of the opening 23a. The space bulge portion 24 forms a substantially horizontal flat upper surface portion 24a immediately before the opening 23a, and a crank chamber oil separator 86 is supported and fixed to this upper surface portion 24a. The space bulge 24 forms a support shape that supports the crank chamber oil separator 86.

Referring also to FIG. 8, a crank chamber oil separator 86 is provided for each left and right oil suction port 72aL, 72aR (for each left and right scavenge pump 51L, 51R). The crank chamber oil separator 86 includes a flat plate-shaped fixing part 87a that overlaps and is fixed to the upper surface part 24a of the space bulging part 24, and a rearward extension that is connected to the rear of the fixing part 87a and extends to a position overlapping with the oil suction port 72a in a plan view. An exit portion 87b is provided. The fixing portion 87a is fixed to the upper surface portion 24a of the space bulging portion 24, for example, by a bolt b1 that is tightened from above (closed crank chamber 23 side). The rear extending portion 87b extends along the tangential direction of the lower end position of the rotational orbit (region) R of the crankshaft 11. A rear end pawl 87c that is bent upward so as to approach the outer circumference of the crankshaft 11 is formed at the tip of the rear extending portion 87b.

The crank chamber oil separator 86 is disposed below the crankshaft 11 when viewed from the axial direction of the crankshaft 11 so that the rear extending portion 87b extends in the reverse direction of the crankshaft 11. The rear end claw 87c of the rearward extending portion 87b of the crank chamber oil separator 86 peels off the engine oil that is attached to the outer periphery of the crankshaft 11 (crank web 13) and moves around, and scrapes it downward. The scraped engine oil falls toward the oil suction port 72a located directly below the crank chamber oil separator 86, and is received by the oil suction port 72a.

If a large amount of engine oil remains attached to the outer periphery of the crank web 13, friction occurs due to flow resistance of the engine oil at a portion where the distance between the crank web 13 and the inner wall of the crankcase 20 narrows. On the other hand, by appropriately scraping off the engine oil on the outer periphery of the crank web 13, the oil resistance generated within the crankcase 20 is reduced.

<ACG>
Referring to FIGS. 6 and 8, an ACG (AC Generator) 17 is arranged at the left end of the crankshaft 11.
The ACG 17 is arranged coaxially with the crankshaft 11 so that the rotational center axis C1 coincides with the crankshaft 11. The ACG 17 is driven by the rotation of the crankshaft 11 during engine operation to generate electricity. The ACG 17 includes, for example, a stator (not shown) having a plurality of coils arranged in a circumferential direction around the center of the crankshaft and fixed to the ACG cover 27, and a rotor having a plurality of magnets facing the plurality of coils of the stator in the radial direction. It is equipped with 19. The rotor 19 is supported by the crankshaft 11 so as to be able to rotate integrally therewith. For example, the ACG 17 may function as a starter motor that starts the engine 7 or as an assist motor that assists in driving the engine 7.

The rotor 19 has a bowl shape (cylindrical shape with a bottom) that opens outward in the vehicle width direction, and has magnets facing the stator coils from the outside in the radial direction. Hereinafter, the rotor 19 will be referred to as an outer rotor 19.
The outer rotor 19 includes a disc-shaped rotor bottom wall part 19a that is perpendicular to the axial direction, and a cylindrical rotor peripheral wall part 19b that extends outward in the vehicle width direction from the outer periphery of the rotor bottom wall part 19a. . The outer rotor 19 functions as a flywheel whose mass is increased by increasing the thickness of the rotor bottom wall portion 19a. The rotor peripheral wall portion 19b holds a plurality of magnets on its inner peripheral surface.

The front left side of the crankcase 20 is open outward in the vehicle width direction. A left case cover 27 is attached to the front left side of the crankcase 20 so as to cover this open portion from the outside in the vehicle width direction. The front left side of the crankcase 20 and the left case cover 27 form an ACG chamber (generator chamber) 28 on the front left side of the crankcase 20 (left side of the crankshaft 11) to accommodate the ACG 17. Hereinafter, the left case cover 27 will be referred to as the ACG cover (generator cover) 27. Further, a portion of the front left side of the crankcase 20 that is open to the outside in the vehicle width direction is referred to as an ACG indoor side portion 25. The ACG chamber 28 is an oil chamber in which engine oil circulates. Engine oil for lubricating the rotating parts of the ACG 17 is supplied into the ACG chamber 28 .

<ACG cover>
Referring to FIGS. 7 to 10, the ACG cover 27 has a container shape that opens inward (right side) in the vehicle width direction. The ACG cover 27 includes a plate-shaped cover outer wall 27a that is perpendicular to the axial direction of the ACG 17, and a cover peripheral wall 27b that extends inward in the vehicle width direction from the outer periphery of the cover outer wall 27a. A lower cover 27c is integrally provided below the ACG cover 27 to cover the periphery of the left end of a rotating body (for example, a water pump, a balancer shaft, etc.) disposed below the crankshaft 11. Reference numeral K3 in the figure indicates a lower storage chamber covered by the lower cover 27c.

The ACG chamber 28 forms a circular space K1 that is generally coaxial with the crankshaft 11 when viewed from the side (viewed in the axial direction), and also has a protruding space that has a triangular shape when viewed from the side and protrudes outward in the radial direction at the rear lower part of the circular space K1. It forms K2. Reference numeral 27d in the figure indicates an outer wall protrusion that covers the outside of the protrusion space K2 at the rear lower part of the cover outer wall 27a. The lower part of the cover peripheral wall portion 27b constitutes a middle cover wall 27e that partitions the ACG chamber 28 and the lower storage chamber K3. The middle cover wall 27e is formed in a flat shape that slopes downward toward the rear when viewed from the side. The rear lower side of the cover peripheral wall portion 27b extends linearly along the front end of the protrusion space K2 when viewed from the side. The lower rear side of the cover peripheral wall portion 27b forms a flat rear lower extending portion 27f extending in the vertical direction. The rear lower extending portion 27f is inclined so that the lower side is located toward the front side with respect to the up-down direction when viewed from the side.

Referring to FIGS. 6 and 7, the ACG indoor side part 25 on the front left side of the crankcase 20 includes an inner wall part (partition wall) 25a that faces the cover outer wall part 27a of the ACG cover 27 in the axial direction, and an inner wall part 25a of the inner wall part 25a. It includes an inner peripheral wall portion 25b that extends outward in the vehicle width direction from the outer periphery. The inner wall portion 25a and the inner peripheral wall portion 25b are formed to overlap with the cover outer wall portion 27a and the cover peripheral wall portion 27b, respectively, in a side view. The inner circumferential wall portion 25b is connected to the cover circumferential wall portion 27b inward in the vehicle width direction. Hereinafter, the part of the cover peripheral wall part 27b of the inner peripheral wall part 25b that overlaps with the cover middle wall 27e will be referred to as the inner middle wall 25c, and the part of the inner peripheral wall part 25b that overlaps with the rear lower extending part 27f of the cover peripheral wall part 27b will be referred to as the inner rear lower extending part. It is called part 25d.

The cover middle wall 27e and the inner middle wall 25c constitute a lower wall portion 29a located below the ACG chamber 28, and the rear lower extending portion 27f and the inner rear lower extending portion 25d constitute a lower rear wall portion 29a of the ACG chamber 28. It constitutes a rear lower wall portion 29b located at the rear.
The inner wall portion 25a constitutes a partition wall 25a that partitions the ACG chamber 28 and the closed crank chamber 23 in the axial direction. A portion of the partition wall 25a that faces the outer wall protrusion 27d of the cover outer wall portion 27a in the axial direction is referred to as a partition protrusion 25e.

<Communication section>
Referring to FIGS. 6 and 8, a communication portion 45 that communicates between the ACG chamber 28 and the sealed crank chamber 23 is formed through the partition wall protrusion 25e. The communication portion 45 has an opening 45a at one end that opens into the ACG chamber 28, an opening 45b at the other end that opens into the sealed crank chamber 23, and a communication path 45c spanning between the opening 45a at one end and the opening 45b at the other end. There is. The communication path 45c is an oil flow path that is inclined so that the closer to the closed crank chamber 23 the lower the position in the cross-sectional view of FIG. 8 is. One end opening 45a that opens into the ACG chamber 28 opens at the side surface (partition protrusion 25e) of the lower end of the ACG chamber 28. Hereinafter, the opening 45a at one end of the communication portion 45 will be referred to as a first opening 45a, and the opening 45b at the other end will be referred to as a second opening 45b.

Engine oil is supplied into the ACG chamber 28 to lubricate the rotating parts of the ACG 17 during engine operation (ACG operation). The engine oil supplied into the ACG chamber 28 reaches the sealed crank chamber 23 through the communication portion 45 (communication path 45c), and is sucked into the scavenge pumps 51L and 51R together with the engine oil in the sealed crank chamber 23. The lower wall portion 29a of the ACG chamber 28 is inclined backwardly toward the communication portion 45, and the rear lower wall portion 29b of the ACG chamber 28 extends downward toward the communication portion 45. Therefore, the engine oil that has scattered around the outer circumferential portion of the ACG 17 and adhered to the lower wall portion 29a and the rear lower wall portion 29b is smoothly guided to the communication portion 45. The communication portion 45 (communication path 45c) guides the engine oil particularly toward the oil suction port 72aL of the left scavenge pump 51L when returning the engine oil in the ACG chamber 28 to the closed crank chamber 23.

The second opening 45b of the communication portion 45 on the closed crank chamber 23 side is arranged vertically above the oil suction port 72aL of the left scavenge pump 51L when viewed from the side. For example, the second opening 45b of the communication portion 45 is arranged along the left edge 72b (see FIG. 4) of the oil suction port 72aL of the left scavenge pump 51L in a plan view of FIG. The oil suction port 72aL of the left scavenge pump 51L is arranged so as to overlap the extension region 45d of the communication portion 45 on the closed crank chamber 23 side when viewed from the front and back direction (see FIG. 8). As a result, the engine oil guided into the sealed crank chamber 23 through the communication portion 45 does not flow excessively in plan view or in the vertical direction. will be entered directly. This prevents oil from remaining in the sealed crank chamber 23 and prevents an unnecessary increase in friction.

Referring to FIG. 4, the pump rotor 57 is exposed upward below the oil suction port 72aL. The second opening 45b of the communication passage 45c is arranged vertically above the oil suction port 72aL of the left scavenge pump 51L and the pump rotor 57 when viewed from the side. Since the engine oil that has entered the oil suction port 72aL flows down onto the pump rotor 57, it is possible to efficiently utilize the function of the left scavenge pump 51L.

Referring to FIGS. 5 and 8, the second opening 45b of the communication portion 45 is located at a height that overlaps the crank chamber oil separator 86 in the vertical direction. The second opening 45b is arranged rearward of the crank chamber oil separator 86. The crank chamber oil separator 86 has a rear end pawl 87c arranged near the lower end of the rotational path R of the crankshaft 11. The second opening 45b is arranged behind the lower end of the rotational path R of the crankshaft 11. The second opening 45b is arranged upstream of the rear end pawl 87c in the rotational direction F of the crankshaft 11. The outer peripheral edge of the rotational orbit R indicates the rotational orbit of the outermost peripheral part of the crankshaft 11 (for example, the outer peripheral part of the crank web 13). The second opening 45b is arranged on the outer circumferential side of the outer circumferential edge of the rotation orbit R of the crankshaft 11. The second opening 45b is arranged so as to protrude below the lower end position of the rotational path R of the crankshaft 11.

The engine oil scraped off by the crank chamber oil separator 86 has momentum due to the rotation of the crankshaft 11. This engine oil flows forward and downward of the rear end pawl 87c and then reaches the oil suction port (see arrow f1 in the figure). Therefore, the engine oil scraped off by the crank chamber oil separator 86 does not flow near the communication section 45 behind the rear end pawl 87c, and does not affect the oil flow from the communication section 45. Since the oil in the communication portion 45 flows by natural dripping due to the slope of the communication path 45c (see arrow f2 in the figure), the effect of avoiding disturbance is great.

<First embodiment of ACG chamber oil separator>
Referring to FIGS. 6 to 12, the engine 7 of the embodiment includes an ACG chamber oil separator 100 for scraping off engine oil that is carried along with the outer rotor 19 of the ACG 17. The ACG chamber oil separator 100 of the first embodiment is supported and fixed to the ACG cover 27. The ACG chamber oil separator 100 is arranged on the outer peripheral side of the ACG 17 when viewed from the side. The ACG chamber oil separator 100 is fixed inside the cover outer wall 27a (outer wall protrusion 27d) of the ACG cover 27. The ACG chamber oil separator 100 includes a flat base 101 fixed to the inner surface of the cover outer wall 27a (outer wall protrusion 27d) of the ACG cover 27, and a flat base 101 that is bent inward in the vehicle width direction from the side edge of the base 101 on the ACG 17 side. and an inner extending portion 102 extending inward.

The base portion 101 has a pair of bolt insertion holes 101a formed therein and includes a pair of knock pins 101b that protrude toward the cover outer wall portion 27a.
The inner extending portion 102 includes a curved portion 102a that curves in an arc shape in a side view along the outer circumferential surface of the ACG 17, and a curved portion 102a that extends radially outward from an edge of the curved portion 102a on the downstream side in the rotation direction F of the outer rotor 19. A bent piece 102b that extends in a bent manner. As a result, the ACG chamber oil separator 100 has a box shape with three mutually intersecting sides, increasing component strength.
The curved portion 102a is arranged below the outer rotor 19 and along the outer peripheral surface of the outer rotor 19. Peeling claws 102c for peeling off engine oil adhering to the outer periphery of the outer rotor 19 are formed at the edge of the curved portion 102a on the upstream side in the rotation direction F of the outer rotor 19.

The peeling pawl 102c of the ACG chamber oil separator 100 peels off the engine oil adhering to the outer periphery of the outer rotor 19 and scraping it off toward the bottom of the peeling pawl 102c. The scraped engine oil flows rearward and downward on the lower wall portion 29a of the ACG chamber 28, and flows into the communication portion 45 located inside the ACG chamber oil separator 100 in the vehicle width direction. This engine oil reaches the closed crank chamber 23 through the communication portion 45 and is received by the oil suction port 72aL of the left scavenge pump 51L.

The cover outer wall portion 27a of the ACG cover 27 is provided with a separator fixing portion 103 for fastening and fixing the base portion 101 of the ACG chamber oil separator 100 with bolts b2. In the figure, reference numeral 103a indicates a screw hole into which the bolt b2 is tightened in the separator fixing portion 103, and reference numeral 103b indicates a knock hole into which the knock pin 101b protruding from the base 101 is engaged. The screw hole is a blind hole that is closed on the outside in the vehicle width direction of the cover outer wall portion 27a of the ACG cover 27.

Since the flywheel (outer rotor 19) attached to the crankshaft 11 rotates at the same number of rotations as the crankshaft 11, friction due to oil stirring is large. Since the stirring oil on the outer peripheral side of the flywheel is scraped off by the ACG chamber oil separator 100, the friction reduction effect is high.

Since a separate ACG chamber oil separator 100 is attached to the ACG cover 27 side, even if the size of the flywheel (and even the ACG 17) is changed, only the ACG chamber oil separator 100 can be replaced without changing the ACG cover 27 itself. It is possible to deal with this. The gap (oil flow path) between the inner surface of the ACG chamber 28 and the ACG chamber oil separator 100 can be adjusted by changing the shape of the separator.

The flywheel (ACG 17) is stored so as to protrude more toward the ACG cover 27 than the ACG indoor side portion 25 of the crankcase 20. Therefore, the ACG chamber oil separator 100 can be smaller when installed on the ACG cover 27 side than on the crankcase 20 side, and it is easier to obtain advantages in terms of space and weight. Furthermore, the mounting surface of the ACG chamber oil separator 100 does not have to interfere with the arrangement of the communication section 45, increasing the degree of freedom in designing the communication section 45.

<Second embodiment of ACG chamber oil separator>
Next, the ACG chamber oil separator 110 of the second embodiment will be described.
Referring to FIGS. 13 to 18, the ACG chamber oil separator 110 of the second embodiment is supported and fixed to the partition wall 25a of the crankcase 20. The ACG chamber oil separator 110 includes a flat base 111 fixed to the outer surface of the partition wall 25a, and an outer extending portion 112 that bends and extends outward in the vehicle width direction from the outer peripheral side edge of the ACG 17 at the base 111. It is equipped with The base 111 is disposed on the inner peripheral side of the ACG 17 (at a position overlapping the outer rotor 19) when viewed from the side. The outer extending portion 112 includes a curved portion 112a that curves in an arc shape when viewed from the side so as to follow the outer circumferential surface of the ACG 17.

The base 111 is provided with a pair of bolt insertion holes 111a and a pair of knock pins 111b that protrude toward the partition wall 25a.
The curved portion 112a is disposed at the lower rear of the outer rotor 19 along the outer circumferential surface of the outer rotor 19. Peeling claws 112b for peeling off engine oil adhering to the outer periphery of the outer rotor 19 are formed at the edge of the curved portion 112a on the upstream side in the rotation direction F of the outer rotor 19.

The peeling pawl 112b of the ACG chamber oil separator 110 peels off the engine oil adhering to the outer periphery of the outer rotor 19 and scraping it off toward the bottom of the peeling pawl 112b. The scraped engine oil flows rearward and downward on the lower wall portion 29a of the ACG chamber 28, and flows into the communication portion 45 located below the ACG chamber oil separator 110. This engine oil reaches the closed crank chamber 23 through the communication portion 45 and is received by the oil suction port 72aL of the left scavenge pump 51L.

The partition wall 25a of the crankcase 20 is provided with a separator fixing part 113 for fastening and fixing the base part 111 of the ACG chamber oil separator 110 with a bolt b3. The separator fixing portion 113 is arranged so as to avoid the fastening region 20a for fastening the upper and lower halves of the crankcase 20. In the figure, reference numeral 113a indicates a screw hole into which the bolt b3 is tightened in the separator fixing portion 113, and reference numeral 113b indicates a knock hole into which the knock pin 111b protruding from the base 111 is engaged.

Here, the outer rotor 19 has a bowl shape that opens outward in the vehicle width direction (ACG cover 27 side), and its outer peripheral surface has a cylindrical shape with the outer peripheral surface (outer peripheral surface 19c) extending in the axial direction. On the other hand, the inner portion in the vehicle width direction (inner outer circumferential surface 19d) has a tapered shape whose diameter decreases toward the inner side in the vehicle width direction.
The outer extending portion 112 (curved portion 112a) of the ACG chamber oil separator 110 has a bent portion in the middle of extending outward in the vehicle width direction. A portion of the outer extending portion 112 on the outer side in the vehicle width direction than the bent portion (outside portion) is arranged along the outer peripheral surface 19c of the outer rotor 19. A portion (inner portion) of the outer extending portion 112 on the inner side in the vehicle width direction than the bent portion is arranged along the inner outer circumferential surface 19d of the outer rotor 19.

Engine oil adhering to the cylindrical outer peripheral surface along the axial direction can be easily scraped off regardless of whether the ACG side oil separator is installed on either the ACG cover 27 side or the crankcase 20 side. Engine oil adhering to the tapered surface of the outer rotor 19 whose diameter decreases from the outer peripheral surface to the bottom surface is easier to scrape off with the ACG oil separator installed on the crankcase 20 side (bottom side) than on the ACG cover 27 side. If the mounting surface of the ACG chamber oil separator 110 is arranged at a position overlapping the outer rotor 19 in a side view, the arrangement of the communication portion 45 can be avoided.

As described above, the engine 7 in the above embodiment includes a crankcase 20 that forms a sealed crank chamber 23 that accommodates the crankshaft 11, and a plurality of crankcases 20 that suck engine oil flowing down from the sealed crank chamber 23 and return it to the oil pan 40. scavenge pumps 51L and 51R, and an ACG chamber 28 that accommodates the ACG 17 is formed on one axial side (left side) of the crankshaft 11 in the crankcase 20, and the ACG chamber 28 and the sealed crank chamber 23 are separated. The partitioning wall 25 a is provided with a communication part 45 that communicates the ACG chamber 28 and the sealed crank chamber 23 , and the communication part 45 connects the engine oil that has flowed into the ACG chamber 28 to the left scavenge opening into the sealed crank chamber 23 . It is guided to the oil suction port 51aL of the pump 51L.

According to this configuration, the engine oil in the closed crank chamber 23 is discharged to the outside of the closed crank chamber 23 by the scavenge pumps 51L and 51R, and the engine oil that has flowed into the ACG chamber 28 is removed from the communication section provided in the partition wall 25a. 45, the oil is directly led to the oil suction port 51aL of at least one scavenge pump (left scavenge pump 51L) that opens into the closed crank chamber 23. Therefore, compared to a configuration in which the communication portion 45 guides the engine oil to a portion of the sealed crank chamber 23 that avoids the oil suction port 51aL, the engine oil can be discharged out of the sealed crank chamber 23 more quickly. Therefore, the amount of oil sucked in and the amount of oil discharged by the scavenge pumps 51L, 51R can be easily increased, and the oil resistance generated within the crankcase 20 (resistance during power transmission by the crankshaft 11) can be reduced.

In the engine 7, the opening 45b of the communication portion 45 on the closed crank chamber 23 side is arranged vertically above the oil suction port 51aL of the left scavenge pump 51L and the pump rotor 53L when viewed from the side.
According to this configuration, the engine oil that has passed through the communication portion 45 directly enters the oil suction port 51aL of the left scavenge pump 51L and is directly sucked into the pump rotor 53L, so that the oil remains in the closed crank chamber 23. This can prevent unnecessary increases in friction.

In the engine 7, the opening 45b of the communication portion 45 on the closed crank chamber 23 side is arranged below the rotational orbit R of the crankshaft 11.
According to this configuration, the engine oil flowing into the sealed crank chamber 23 from the communication portion 45 is prevented from being rolled up by the crankshaft 11, so that the engine oil in the ACG chamber 28 can be smoothly transferred to the outside of the sealed crank chamber 23. Can be discharged. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced.

In the engine 7 described above, a crank chamber oil separator 86 is provided in the sealed crank chamber 23 to scrape off the stirring oil on the outer peripheral side of the crankshaft 11, and the communication portion 45 is arranged below the crank chamber oil separator 86. .
According to this configuration, the engine oil flowing through the communication path 45c and the engine oil scraped off by the crank chamber oil separator 86 in the closed crank chamber 23 are less likely to interfere with each other. Therefore, each engine oil in the ACG chamber 28 and the closed crank chamber 23 can be smoothly discharged to the outside of the closed crank chamber 23. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced.

In the engine 7, the lower wall portion 29a of the ACG chamber 28 is inclined downward toward the rear, and the communication portion 45 is disposed at the rear lower portion of the ACG chamber 28.
According to this configuration, the engine oil dripped onto the lower wall portion 29a of the ACG chamber 28 is naturally guided toward the communication portion 45 at the rear lower part of the ACG chamber 28, so that the engine oil flowing into the ACG chamber 28 is It becomes easier to aggregate. Therefore, the engine oil in the ACG chamber 28 can be smoothly discharged to the outside of the sealed crank chamber 23. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced. Since the crankshaft 11 rotates backward, the engine oil scattered from the outer circumference of the crankshaft 11 tends to collide head-on with the lower wall 29a of the ACG chamber 28, making it easy to separate the engine oil into gas and liquid. be able to.

Further, the engine 7 in the above embodiment includes a crankcase 20 that forms a sealed crank chamber 23 that accommodates the crankshaft 11, and the ACG 17 is accommodated on one side (left side) in the axial direction of the crankshaft 11 in the crankcase 20. The ACG chamber 28 is provided with at least one of an ACG chamber oil separator 100 or 110 for scraping off stirring oil on the outer peripheral side of the ACG 17.

According to this configuration, since the stirring oil adhering to the outer circumferential side of the ACG 17 is scraped off by the ACG chamber oil separators 100 and 110, it is possible to prevent the engine oil from scattering due to the rotation of the ACG 17. Therefore, the engine oil in the ACG chamber 28 can be efficiently collected, and the oil resistance generated in the ACG 17 can be reduced.

The engine 7 is equipped with scavenge pumps 51L and 51R that suck engine oil flowing down from the closed crank chamber 23 and return it to the oil pan 40. The lower wall portion 29a of the ACG chamber 28 is provided with a communication portion 45 that communicates with the closed crank chamber, and the lower wall portion 29a of the ACG chamber 28 is inclined downwardly toward the rear, and the communication portion 45 is disposed at the rear lower portion of the ACG chamber 28.
According to this configuration, the engine oil dripped onto the lower wall portion 29a of the ACG chamber 28 is naturally guided toward the communication portion 45 at the rear lower part of the ACG chamber 28, so that the engine oil flowing into the ACG chamber 28 is It becomes easier to aggregate. Therefore, the engine oil in the ACG chamber 28 can be smoothly discharged to the outside of the sealed crank chamber 23. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced.

In the engine 7 described above, the ACG chamber oil separators 100 and 110 are arranged above the communication portion 45.
According to this configuration, the engine oil scraped off by the ACG chamber oil separators 100, 110 is immediately guided to the communication portion 45 and led out of the closed crank chamber 23. Therefore, the engine oil in the ACG chamber 28 can be smoothly discharged to the outside of the sealed crank chamber 23. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced.

In the engine 7, an ACG cover 27 that covers the ACG chamber 28 is attached to one axial side (left side) of the crankcase 20, and the ACG chamber oil separator 100 is attached to the ACG cover 27.
According to this configuration, the ACG chamber oil separator 100 is attached to the ACG cover 27 side instead of the crankcase 20 side (partition wall 25a side, communication part 45 side), so the base 101 (attachment part) of the ACG chamber oil separator 100 is attached to the ACG cover 27 side. This does not affect the arrangement of the communication portion 45 of the partition wall 25a. That is, the individual designs of the ACG chamber oil separator 100 and the communication portion 45 do not interfere with each other. Therefore, the engine oil can be efficiently scraped off by the ACG chamber oil separator 100, and the engine oil can be efficiently guided to the sealed crank chamber 23 by the communication portion 45. This engine oil is smoothly discharged to the outside of the closed crank chamber 23 by a scavenge pump located below the closed crank chamber 23. Therefore, the resistance (oil resistance) during power transmission by the crankshaft 11 can be reduced. Furthermore, since the ACG chamber oil separator 100 is installed on the ACG cover 27, it is possible to easily install the ACG chamber oil separator 100 with a different shape, etc., and the amount of engine oil discharged outside the sealed crank chamber 23 can be easily adjusted. can do.

Note that the present invention is not limited to the above-described embodiments; for example, in the above-described embodiments, the present invention is applied to a V-type four-cylinder engine, but the scope of application of the present invention is not limited thereto. That is, the present invention may be applied to various internal combustion engines having a sealed crank chamber. Further, the present invention may be applied to an internal combustion engine with a separate transmission.
The internal combustion engine of this embodiment may be applied to saddle-ride type vehicles other than motorcycles. The saddle-riding type vehicle includes all types of vehicles in which the driver rides astride the body of the vehicle, and includes not only motorcycles (including motorized bicycles and scooter-type vehicles) but also three-wheeled vehicles (including one front wheel and two rear wheels). , vehicles with two wheels in the front and one wheel in the rear) or vehicles with four wheels (four-wheel buggy, etc.) are also included.
The present invention may be applied to a vehicle that includes an electric motor as a prime mover. Furthermore, the present invention may be applied to vehicles other than saddle-ride vehicles (passenger cars, buses, trucks, etc.).
Furthermore, although the internal combustion engine of this embodiment is applied to a vehicle, the present invention is not limited to application to vehicles, and can be applied to various transportation equipment such as aircraft and ships, as well as various vehicles such as construction machinery and industrial machinery. It may also be applied to mobile objects. Furthermore, the present invention is widely applicable to devices other than vehicles that include an internal combustion engine, such as hand-operated lawn mowers and cleaning machines.
The configuration in the embodiment described above is an example of the present invention, and various changes can be made without departing from the gist of the present invention, such as replacing the constituent elements of the embodiment with well-known constituent elements.

1 Motorcycle (saddle type vehicle)
7 Engine (internal combustion engine)
11 Crankshaft 17 ACG (generator)
20 Crank case 23 Sealed crank chamber (crank chamber)
25a Bulkhead 27 ACG cover (generator cover)
28 ACG room (generator room)
29a Lower wall part 40 Oil pan (oil storage part)
45 Communication portions 51L, 51R Scavenge pump 53L Pump rotor 72aL Oil suction port 86 Crank chamber oil separator 100, 110 ACG chamber oil separator (generator chamber oil separator)
R Rotating orbit

Claims (6)

a crankcase (20) forming a crank chamber (23) that accommodates the crankshaft (11);
An internal combustion engine comprising a scavenge pump (51L, 51R) that sucks engine oil flowing down from the crank chamber (23) and returns it to the oil storage part (40),
A generator chamber (28) that accommodates a generator (17) is formed on one side of the crankcase (20) in the axial direction of the crankshaft (11),
The partition wall (25a) that partitions the generator room (28) and the crank room (23) is provided with a communication part (45) that communicates the generator room (28) and the crank room (23),
The communication portion (45) guides the engine oil flowing into the generator chamber (28) to the oil suction port (72aL) of the scavenge pump (51L) that opens into the crank chamber (23). Internal combustion engine. The internal combustion engine according to claim 1, wherein the communication portion (45) is arranged above the oil suction port (72aL). The internal combustion engine according to claim 1, wherein the communication portion (45) is arranged above a pump rotor (53L) of the scavenge pump (51L). The internal combustion engine according to claim 1, wherein the communication portion (45) is arranged below a rotation orbit (R) of the crankshaft (11). A crank chamber oil separator (86) is provided in the crank chamber (23) for scraping off stirring oil on the outer peripheral side of the crankshaft (11),
The internal combustion engine according to claim 1, wherein the communication portion (45) is located below the crank chamber oil separator (86). The lower wall portion (29a) of the generator room (28) is inclined backwardly,
The internal combustion engine according to any one of claims 1 to 5, wherein the communication portion (45) is disposed at a rear lower portion of the generator chamber (28).

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