WO2019026989A1 - Engine and vehicle - Google Patents

Engine and vehicle Download PDF

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Publication number
WO2019026989A1
WO2019026989A1 PCT/JP2018/028981 JP2018028981W WO2019026989A1 WO 2019026989 A1 WO2019026989 A1 WO 2019026989A1 JP 2018028981 W JP2018028981 W JP 2018028981W WO 2019026989 A1 WO2019026989 A1 WO 2019026989A1
Authority
WO
WIPO (PCT)
Prior art keywords
crankshaft
cylinder
engine
balancer shaft
oil
Prior art date
Application number
PCT/JP2018/028981
Other languages
French (fr)
Japanese (ja)
Inventor
真浩 和久田
Original Assignee
ヤマハ発動機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ヤマハ発動機株式会社 filed Critical ヤマハ発動機株式会社
Priority to EP18841325.6A priority Critical patent/EP3663547B1/en
Publication of WO2019026989A1 publication Critical patent/WO2019026989A1/en

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02FCYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F7/00Casings, e.g. crankcases or frames
    • F02F7/0002Cylinder arrangements
    • F02F7/0019Cylinders and crankshaft not in one plane (deaxation)
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/0004Oilsumps
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/02Arrangements of lubricant conduits
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B61/00Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing
    • F02B61/02Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving cycles
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02BINTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B77/00Component parts, details or accessories, not otherwise provided for
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02FCYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F7/00Casings, e.g. crankcases or frames
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/0004Oilsumps
    • F01M2011/0037Oilsumps with different oil compartments
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/0004Oilsumps
    • F01M2011/0083Dry sumps
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01MLUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/0004Oilsumps
    • F01M2011/0087Sump being made of different parts

Definitions

  • the present invention relates to a technology for storing oil supplied to each part of an engine.
  • Patent Document 1 describes an engine employing a dry sump method. In this engine, the oil dropped to the bottom of the crankcase is sucked up by the scavenge pump and stored in the oil storage chamber. And a feed pump supplies oil to each part inside the engine from the oil storage chamber.
  • This invention is made in view of the said subject, and aims at provision of the technique which makes it possible to suppress the enlargement of an engine, ensuring the storage volume of oil widely.
  • the engine according to the present invention comprises a cylinder, a crankcase connected to the cylinder, and at least a part of which is disposed in the crankcase and connected via a connecting rod to a piston reciprocating in the cylinder via the connecting rod.
  • a crankshaft that rotates around a crankshaft in conjunction with movement, an oil pan provided in the crankcase, a reservoir for storing oil, and an oil pan from the oil pan to the reservoir are provided in the crankcase
  • the crankshaft center is located on one side of the cylinder centerline in offset directions orthogonal to the cylinder centerline and the crankshaft center respectively, and at least a portion of the reservoir is in the offset direction. Located on the other side of the center line of the cylinder at It overlaps with the crank shaft.
  • the crankshaft is positioned on one side of the center line of the cylinder, thereby securing a space on the other side of the center line of the cylinder. Then, at least a part of the storage portion is disposed on the other side of the center line of the cylinder so as to overlap the crankshaft as viewed from the offset direction, and this space is effectively used. By this, it is possible to suppress the enlargement of the engine while securing a large storage volume of oil.
  • the present invention exhibits such an effect effectively by utilizing the features of the dry sump method. That is, in the wet sump, the oil is stored in the oil pan itself provided at the bottom of the crankcase. Therefore, a large amount of oil can not be stored to prevent the crankshaft from getting soaked in the oil. On the other hand, since the present invention adopts the dry sump method of sending the oil from the oil pan to the storage portion, the oil storage volume can be widely secured as described above without the crankshaft being soaked in the oil. It is possible.
  • the engine may be configured to further include a transmission disposed in the crankcase, and the transmission is positioned on one side of the center line of the cylinder in the offset direction.
  • the transmission and at least a portion of the reservoir are located on opposite sides of the center line of the cylinder. Therefore, it is possible to secure at least a part of the reservoir without being obstructed by the space for arranging the transmission.
  • the engine may be configured to further include a balancer shaft that rotates in conjunction with the crankshaft between at least a part of the storage portion and the crankshaft. That is, in the present invention, a space is secured on the other side of the center line of the cylinder by positioning the crankshaft on one side of the center line of the cylinder. Therefore, the balancer shaft can be further disposed while securing the oil storage volume on the other side of the center line of the cylinder.
  • the storage portion has a first storage chamber and a second storage chamber arranged in the axial direction of the balancer shaft, and stores oil in the first storage chamber and the second storage chamber,
  • the weight of the balancer shaft is located between both ends of the second storage chamber
  • the first storage chamber is the balancer shaft in the vertical direction perpendicular to the axial direction of the balancer shaft than the second storage chamber.
  • the engine may be configured to have a protruding portion that protrudes to the side, and at least a portion of the protruding portion overlaps the rotation trajectory of the weight of the balancer shaft when viewed from the axial direction of the balancer shaft. In this configuration, the protrusion is provided in the first storage chamber of the storage unit, and more oil can be stored while preventing interference between the storage unit and the balancer shaft.
  • At least a portion of the storage portion is described so as to be located in a direction opposite to the oil pan with respect to a straight line passing through the crankshaft center and the rotation center of the balancer shaft when viewed from the axial direction of the balancer shaft You may configure an engine. Such a configuration contributes to securing a large oil storage volume.
  • the crankcase may have an outer wall portion constituting an outer wall surface, and the engine may be configured such that at least a part of the wall surface of the storage portion is constituted by the outer wall surface of the outer wall portion.
  • the volume in the crankcase can be effectively utilized to secure a large oil storage volume.
  • a vehicle according to the present invention includes the above engine and wheels driven by the engine. Therefore, it is possible to suppress the enlargement of the engine while securing a large storage volume of oil.
  • FIG. 1 is a side view showing a motorcycle which is an example of a straddle-type vehicle equipped with an engine according to the present invention.
  • the fragmentary sectional view which shows the internal structure of an engine by a substantially center cross section.
  • FIG. 4 is a partial cross-sectional view of the engine along the IV-IV cut line shown in FIG. 3;
  • the fragmentary sectional view which shows arrangement of a storage part, a crankshaft, and a balancer shaft.
  • FIG. 1 is a side view showing a motorcycle which is an example of a straddle-type vehicle equipped with an engine according to the present invention.
  • the motorcycle 1 shown in the figure is a so-called off-road type, but the straddle-type vehicle also includes an on-road type, a scooter type, or a so-called moped type motorcycle and the like besides the type.
  • the vehicle according to the present invention includes not only straddle type vehicles but also ATVs (All Terrain Vehicles) and four-wheeled buggies.
  • front, rear, left and right mean front, rear, left and right as viewed from the occupant seated on the seat 10 respectively.
  • front and rear directions Dp, the front side Df in the front and rear directions Dp, the rear side Db in the front and rear directions Dp, the vehicle width direction Dw, and the vertical direction Dv are appropriately shown.
  • the longitudinal direction Dp and the vehicle width direction Dw are both horizontal directions, and the longitudinal direction Dp, the vehicle width direction Dw and the vertical direction Dv are orthogonal to each other.
  • the motorcycle 1 includes a vehicle body frame 2.
  • the vehicle body frame 2 includes a head pipe 21, a main frame 22, a tank rail 23, a seat rail 24, a back stay 25, a down frame 26, and the like.
  • the head pipe 21 is disposed at the front end Df end of the vehicle body frame 2, and the main frame 22 bends downward while extending from the head pipe 21 to the rear side Db.
  • the tank rail 23 is disposed between the head pipe 21 and the tank rail 23, and the fuel tank 31 is attached to the tank rail 23.
  • the seat rail 24 extends from the main frame 22 to the rear side Db, and the seat 10 is attached to the seat rail 24.
  • the rear Db end of the seat rail 24 is connected to the main frame 22 by a back stay 25.
  • the down frame 26 extends downward from the head pipe 21 and is bent to the rear side Db, and the rear side Db ends of the down frame 26 and the main frame 22 are connected.
  • a steering shaft (not shown) is rotatably inserted into the head pipe 21 and a handle 32 is attached to the upper end of the steering shaft. Further, a front fork 33 extending obliquely downward toward the front side Df is attached to the steering shaft, and a front wheel 34 is rotatably attached to a lower end portion of the front fork 33.
  • a pivot shaft 221 is attached to the rear Db end of the main frame 22, and a rear arm 35 is extended from the pivot shaft 221 to the rear Db.
  • the rear arm 35 is attached to the main frame 22 via the rear suspension 36 in a state of being supported by the pivot shaft 221 so as to be pivotable in the vertical direction (vertical direction Dv) about the pivot shaft 221.
  • a rear wheel 37 is rotatably attached to the rear Db end of the rear arm 35.
  • the engine 5 is mounted to the vehicle body frame 2 in a region surrounded by the main frame 22 and the down frame 26. Then, the engine 5 rotationally drives the rear wheel 37 via a secondary reduction mechanism (not shown).
  • the secondary reduction mechanism may be any of a chain drive type, a shaft drive type and a belt drive type.
  • FIG. 2 is a partial cross-sectional view showing the internal configuration of the engine in a substantially central cross section
  • FIG. 3 is a partial cross-sectional view showing the internal configuration of the engine in a cross section outside
  • FIG. 4 is a partial cross-sectional view of the engine along the IV cut line.
  • the engine 5 includes a cylinder block 51, a cylinder head 52 attached to the upper end of the cylinder block 51, and a crankcase 53 attached to the lower end of the cylinder block 51.
  • the cylinder block 51 is formed with a head mating surface 51 a that is a contact surface with the cylinder head 52.
  • a cylinder mating surface 52a which is a contact surface with the cylinder block 51 is formed.
  • the cylinder block 51 and the cylinder head 52 are attached to each other in a state where the head joint surface 51a of the cylinder block 51 and the cylinder joint surface 52a of the cylinder head 52 are in contact with each other.
  • a flange 51 b is formed on the outer peripheral surface of the cylinder block 51
  • a crank mating surface 51 c which is a contact surface with the crank case 53 is formed on the flange 51 b.
  • a crank mating surface 53c which is a contact surface with the cylinder block 51 is formed in the crankcase 53.
  • the engine 5 is a single cylinder type in which a single cylinder 511 is provided in a cylinder block 51.
  • a piston 512 is disposed in the cylinder 511, and the piston 512 can reciprocate in the cylinder 511.
  • the cylinder 511 is disposed rearward. That is, the center line Lc of the cylinder 511 is inclined to the rear side Db with respect to the vertical direction Dv, in other words, the center line Lc of the cylinder 511 is inclined to the rear side Db as it goes upward.
  • the center line Lc of the cylinder 511 can be determined, for example, as a virtual straight line parallel to the direction of the stroke of the piston 512 through the center of the bore in the cylinder 511.
  • the cylinder head 52 has an intake port 522 communicating with the combustion chamber between the upper end surface of the piston 512 and an intake valve 523 opening and closing the intake port 522 with respect to the combustion chamber.
  • the intake valve 523 is biased by a valve spring 524 to a position where the intake port 522 is closed.
  • the intake valve 523 can be opened and closed by rotating the cam shaft 525 in contact with the upper end of the intake valve 523.
  • the cylinder head 52 also has an exhaust port 526 in communication with the combustion chamber, and an exhaust valve 527 for opening and closing the exhaust port 526 relative to the combustion chamber.
  • the exhaust valve 527 is biased by a valve spring 528 to a position where the exhaust port 526 is closed.
  • the exhaust valve 527 can be opened and closed by rotating the cam shaft 529 in contact with the upper end of the exhaust valve 527.
  • the engine 5 is provided with a DOHC (Double Over Head Camshaft) type intake and exhaust valve mechanism provided with camshafts 525 and 529 on the intake side and the exhaust side, respectively.
  • the engine 5 includes a multi-valve mechanism provided with a plurality (two) of intake valves 523 and exhaust valves 527 respectively.
  • the crankcase 53 has a storage portion 54 for storing the mechanical configuration of the engine 5 and a storage portion 55 (oil tank) for storing engine oil circulating in the engine 5, and the storage portion 54 and the storage portion 55 Are separated by a partition 56. Furthermore, the housing portion 54 has a crank chamber 541 inside.
  • the crank chamber 541 is in communication with the cylinder 511, and accommodates the crankshaft 61 disposed parallel to the vehicle width direction Dw.
  • the crankshaft 61 has a crank journal 611 rotatably supported by the crankcase 53 around a crankshaft center C61 parallel to the vehicle width direction Dw, and a crank pin 612 eccentric to the crankshaft center C61.
  • the crank pin 612 is connected to the piston 512 by a connecting rod 62, and the crankshaft 61 rotates around a crankshaft center C61 in conjunction with the reciprocating motion of the piston 512.
  • the crankshaft 61 has a counterweight 613 eccentrically located on the opposite side of the crankpin 612 with respect to the crankshaft center C61, and the counterweight 613 is intended to suppress the vibration.
  • crank chamber 541 accommodates the balancer shaft 63 disposed in parallel to the vehicle width direction Dw.
  • the balancer shaft 63 is rotatably supported by the crankcase 53 about a balancer axial center C63 parallel to the vehicle width direction Dw, and has a weight 631 eccentric to the balancer axial center C63.
  • the balancer shaft 63 rotates in conjunction with the rotation of the crankshaft 61 to suppress the vibration of the crankshaft 61.
  • the primary drive gear 614 is coaxially attached to the crankshaft 61, and the primary drive gear 614 rotates around the crankshaft center C61 together with the crankshaft 61.
  • a balancer gear 632 is coaxially attached to the balancer shaft 63, and the balancer shaft 63 rotates with the balancer gear 632 around a balancer axial center C63.
  • the primary drive gear 614 and the balancer gear 632 are engaged with each other, reduce the rotation of the crankshaft 61 and transmit it to the balancer shaft 63.
  • the engine 5 also includes a generator 64 that generates electric power from the rotational motion of the crankshaft 61.
  • the generator 64 has a flywheel 641 and a stator coil 642 disposed inside the flywheel 641.
  • the flywheel 641 is coaxially attached to the crankshaft 61 and is rotatable with the crankshaft 61 about a crankshaft center C61.
  • the N pole magnet and the S pole magnet are alternately arranged to surround the stator coil 642 from the outside. Then, the generator 64 generates electric power by electromagnetic induction between the magnet and the stator coil 642 generated as the flywheel 641 rotates.
  • crank chamber 541 accommodates the clutch mechanism 65 and the transmission 66.
  • an end of the crankcase 53 in the vehicle width direction Dw is a clutch box 532 that covers the clutch mechanism 65, and protrudes from the cylinder 511 in the vehicle width direction Dw.
  • the clutch mechanism 65 has a clutch housing 651 rotatable around a main axial center C67 parallel to the vehicle width direction Dw, and on the outer periphery of the clutch housing 651 is a primary driven gear 652 centered on the main axial center C65. It is provided.
  • the primary drive gear 614 and the primary driven gear 652 are engaged with each other to configure a primary reduction mechanism that decelerates the rotation of the crankshaft 61 and transmits it to the clutch housing 651.
  • the clutch boss 653 rotatable around the main axial center C67 is disposed inside the clutch housing 651, and rotates together with the friction plate 654 that rotates with the clutch housing 651 and the clutch boss 653.
  • the clutch plates 655 are alternately arranged.
  • the clutch mechanism 65 has a pressure portion 656 biased toward the clutch boss 653 by the elastic force of the clutch spring.
  • the clutch mechanism 65 can transmit the rotation of the clutch housing 651 to the clutch boss 653 by pressing the friction plate 654 and the clutch plate 655 to the clutch boss 653 by the pressure portion 656.
  • the clutch mechanism 65 can interrupt the transmission of the rotation from the clutch housing 651 to the clutch boss 653 by moving the pressure portion 656 to the opposite side of the clutch boss 653 against the elastic force of the clutch spring.
  • the main shaft 67 of the transmission 66 is attached to the clutch boss 653. Therefore, the clutch mechanism 65 can selectively execute the transmission operation of transmitting power from the crankshaft 61 to the main shaft 67 and the blocking operation of blocking transmission of power from the crankshaft 61 to the main shaft 67.
  • the transmission 66 has a main shaft 67 and a drive shaft 68 arranged parallel to the vehicle width direction Dw.
  • the main shaft 67 is rotatably supported by the crankcase 53 around a main axial center C67
  • the drive shaft 68 is rotatably supported by the crankcase 53 around a drive axial center C68 parallel to the vehicle width direction Dw.
  • the main shaft 67 is provided with a plurality of gears 671 that constitute a part of the transmission 66. Therefore, the weight of the main shaft 67 including the plurality of gears 671 is generally heavier than the balancer shaft 63 described above.
  • the main shaft 67 is further provided with a shift fork 672 for sliding the gear 671 in the axial direction of the main shaft 67 (in the vehicle width direction Dw).
  • the drive shaft 68 is provided with a plurality of gears 681 and a shift fork 682 for sliding the gears 681 in the axial direction of the drive shaft 68 (in the vehicle width direction Dw).
  • the shift forks 672 and 682 are provided with shift drums 661 that rotate according to the operation of the driver, and each of the shift forks 672 and 682 corresponds to a position according to the rotation angle of the shift drum 661 Move gears 671, 681.
  • the transmission 66 transmits the rotation of the main shaft 67 to the drive shaft 68 at a gear ratio according to the driver's operation. Then, the rotation of the drive shaft 68 is transmitted to the rear wheel 37 by the secondary reduction mechanism.
  • crank chamber 541 engine oil is cyclically supplied to the crank chamber 541.
  • the bottom of the crank chamber 541 functions as an oil pan 544 for receiving engine oil that has fallen by its own weight.
  • the storage unit 55 stores engine oil in a storage chamber 551 inside thereof.
  • the storage chamber 551 is disposed on the front side Df of the crank chamber 541 and at least partially overlaps the crank chamber 541 in a front view from the front side Df.
  • the engine oil has a composition in which an additive is added to a base oil such as mineral oil, chemically synthesized oil or partially chemically synthesized oil, and is circulated in the engine 5 by a pump (scavenge pump, feed pump).
  • the drive of the pump is performed using the rotation of the crankshaft 61. That is, a pump gear (not shown) engaged with the primary drive gear 614 is coaxially attached to the pump, and the primary drive gear 614 and the pump gear transmit the rotation of the crankshaft 61 to the pump.
  • crankshaft 61 the balancer shaft 63, the main shaft 67, and the drive shaft 68 are arranged in parallel to one another. Then, as shown in FIG. 2, the crankshaft 61 is offset rearward with respect to the center line Lc of the cylinder 511. That is, an imaginary half straight line Lh extending toward the cylinder 511 parallel to the center line Lc of the cylinder 511 with the crankshaft center C61 of the crankshaft 61 at the end is positioned rearward of the center line Lc of the cylinder 511.
  • the center line Lc of the cylinder 511 is located closer to the balancer shaft 63 than the virtual half line Lh in the offset direction Do perpendicular to the center line Lc of the cylinder 511 and the crankshaft center C61.
  • the crankshaft center C61 (or the imaginary half line Lh) is located on one side Do1 of the offset direction Do from the center line Lc of the cylinder 511, and the balancer shaft 63 is offset from the center line Lc of the cylinder 511 It is located on the other side Do2 of the direction Do.
  • the other side Do2 is the opposite side of the one side Do1.
  • the balancer shaft 63 is provided on the opposite side of the main shaft 67 with respect to the virtual half line Lh.
  • “the balancer shaft 63 is provided on the opposite side of the main shaft 67 with respect to the virtual half line Lh” means that the virtual straight line is parallel to the center line Lc of the cylinder 511 through the crankshaft center C61. Is equivalent to the case where the balancer shaft 63 is provided on the opposite side of the main shaft 67.
  • an angle ⁇ 1 (0 ° ⁇ 1 ⁇ 90 °) is provided between the first imaginary line segment L1 between the main axial center C67 and the crankshaft center C61 and the virtual half straight line Lh.
  • An angle ⁇ 2 (0 ° ⁇ 2) is provided between the second imaginary line L2 and the imaginary half line Lh between C63 and the crankshaft center C61.
  • the crankshaft 61, the balancer shaft 63, and the main shaft 67 are disposed such that the angle ⁇ 1 ⁇ the angle ⁇ 2.
  • the angle between the line segment and the half line indicates the inferior angle of the superior angle (angle greater than 180 degrees) and the inferior angle (angle smaller than 180 degrees) formed therebetween. That is, both the angle ⁇ 1 and the angle ⁇ 2 are smaller than 180 degrees.
  • the center line Lc, the virtual half line Lh, the first virtual segment L1 and the second virtual segment L2 used in the description herein are all perpendicular to the axial direction of the crankshaft 61 (the vehicle width direction Dw).
  • the mass of each of the main shaft 67 and the balancer shaft 63 is distributed on both sides of an imaginary half straight line Lh extending to the cylinder 511 side parallel to the center line Lc of the cylinder 511 with the crankshaft center C61 as an end.
  • the arrangement of the main shaft 67 affects the concentration of mass. Therefore, in the present embodiment, the main shaft 67 is disposed so as to satisfy the angle ⁇ 1 ⁇ the angle ⁇ 2. That is, in order to satisfy this angular relationship, the main axis 67 is disposed close to the virtual half line Lh having the crankshaft center C61 as an end to achieve mass concentration.
  • the lower end 55 B of the reservoir 55 is disposed below the crankshaft 61, and the upper end 55 T (portion above the lower end 55 B) of the reservoir 55 is an offset of the crankshaft 61. It is arranged on the other side Do2 of the direction Do.
  • the upper end 551T of the storage chamber 551 provided in the upper end 55T of the storage portion 55 is also located on the other side Do2 of the offset direction Do of the crankshaft 61.
  • the balancer shaft 63 is disposed so as to be sandwiched between the upper end 55T of the storage chamber 551 and the crankshaft 61 in the offset direction Do.
  • FIG. 5 is a block diagram showing an example of an oil circulation system provided in the engine. Arrows in FIG. 5 indicate the direction in which the engine oil flows.
  • the engine 5 includes a scavenge pump 91 driven by rotation of a pump gear, and the scavenge pump 91 is connected to the crank chamber 541 via a pipe T1. Therefore, the engine oil that has dropped into the oil pan 544 in the crank chamber 541 is sucked by the scavenge pump 91 and discharged from the crank chamber 541. At this time, engine oil is filtered by a strainer 547 in the crank chamber 541 and then discharged to the scavenge pump 91.
  • the scavenge pump 91 pressure-feeds the sucked engine oil to the pipe T2 communicating with the reservoir 55. Therefore, the engine oil delivered from the scavenge pump 91 is returned to the reservoir 55 via the pipe T2. Thus, the engine oil sucked from the crank chamber 541 by the scavenge pump 91 is stored in the storage portion 55.
  • the reservoir 55 and the crank chamber 541 communicate with each other through the pipe T3, and the engine oil overflowing in the reservoir 55 is discharged to the crank chamber 541 through the pipe T3.
  • the engine 5 includes a feed pump 93 driven by rotation of a pump gear, and the feed pump 93 is connected to the reservoir 55 via a pipe T4. Therefore, the engine oil stored in the storage portion 55 is sucked by the feed pump 93 and discharged from the storage portion 55. At this time, the engine oil is filtered by the strainer 552 in the reservoir 55 and then discharged to the feed pump 93.
  • the feed pump 93 is connected to the relief valve 94 through the pipes T5 and T6. When the pressure at the feed pump 93 becomes larger than a predetermined value, the relief valve 94 operates to discharge the engine oil from the feed pump 93 to the pipe T5, and the engine oil returns to the feed pump 93 via the pipe T6.
  • the feed pump 93 pressure-feeds the engine oil sucked from the reservoir 55 to the oil cleaner 95 through the pipe T7.
  • the pipe T8 and the pipe T9 are connected to the output side of the oil cleaner 95, and the engine oil pressure-fed to the oil cleaner 95 is purified by the oil cleaner 95 and then flows out to the pipes T8 and T9.
  • the pipe T8 is in communication with the crankshaft 61 in the crank chamber 541, and supplies engine oil to the crank journal 611 and the crank pin 612 on the right side of the crankshaft 61.
  • the pipe T9 supplies engine oil to each of the piston 512 and the left crank journal 611, and then extends to the cylinder head 52 to supply engine oil to the camshafts 525 and 529.
  • the pipe T9 branches into the pipe T10 and the pipe T11.
  • the pipe T10 supplies engine oil to the main shaft 67, the primary driven gear 652, and the clutch mechanism 65 in this order.
  • the pipe T11 supplies engine oil to the mission shower 683 and the drive shaft 68 in this order.
  • the engine oil supplied to the mission shower 683 is poured from the mission shower 683 to the drive shaft 68.
  • FIG. 6 is a view showing the arrangement of the storage section and the crankshaft as viewed from the other side in the offset direction toward the one side
  • FIG. 7 is a partial sectional view showing the arrangement of the storage section, the crankshaft and the balancer shaft It is.
  • the crankshaft 61 when the piston 512 is located at the top dead center is shown, and a portion of the crankshaft 61 hidden by the reservoir 55 is shown by a broken line.
  • FIG. 6 is a view showing the arrangement of the storage section and the crankshaft as viewed from the other side in the offset direction toward the one side
  • FIG. 7 is a partial sectional view showing the arrangement of the storage section, the crankshaft and the balancer shaft It is.
  • the crankshaft 61 when the piston 512 is located at the top dead center is shown, and a portion of the crankshaft 61 hidden by the reservoir 55 is shown by a broken line.
  • FIG. 6 is a view showing the arrangement of the storage section and the crankshaft as viewed from the
  • FIG. 7 shows the arrangement in a top view when the weight 631 of the balancer shaft 63 is closest to the front side Df, and the rotation locus 631T of the weight 631 of the balancer shaft 63 (that is, the area passing through one rotation of the weight 631) Together. Further, in FIG. 7, the right side Dr and the left side Dl in the vehicle width direction Dw are shown.
  • the upper end 55T of the storage portion 55 and the upper end 551T of the storage chamber 551 therein are disposed on the other side Do2 of the offset direction Do of the crankshaft 61.
  • the upper end 55T of the reservoir 55 overlaps the crankshaft 61, and a part of the crankshaft 61 is hidden by the upper end 55T of the reservoir 55. More specifically, the entire left and right crank journals 611 are hidden at the upper end 55T of the reservoir 55.
  • the storage chamber 551 of the storage unit 55 is divided into a first storage chamber 553 and a second storage chamber 554 by the partition wall 555, and the first storage chamber 553 and the second storage chamber 554. Are adjacent to each other in the vehicle width direction Dw with the partition wall 555 interposed therebetween.
  • the first storage chamber 553 and the second storage chamber 554 are arranged in the axial direction of the balancer shaft 63, that is, in the vehicle width direction Dw.
  • the first storage chamber 553 on the left side Dl is a projecting portion 553J that protrudes from the second storage chamber 554 on the right side Dr to the rear side Db (balancer shaft 63 side). Is provided.
  • the first and second storage chambers 553 and 554 are provided over the entire storage chamber 551 including the upper end portion 551T and are in communication with each other. Therefore, engine oil can pass between the first reservoir 553 and the second reservoir 554.
  • the weight 631 of the balancer shaft 63 is arranged as follows with respect to the first and second storage chambers 553 and 554. That is, the rotation locus 631T of the weight 631 is located on the right side Dr (that is, the second storage chamber 554 side) in the vehicle width direction Dw of the protrusion 553J of the first storage chamber 553. Then, in the vehicle width direction Dw, both ends 631r, 6311 of the rotation locus 631T of the weight 631 are located between the both ends 554r, 554l of the second storage chamber 554. The rotation locus 631T of the weight 631 faces the projection 553J while being separated in the vehicle width direction Dw.
  • the end 631f of the front side Df of the weight 631 is located on the front side Df from the end 553b of the rear side Db of the protrusion 553J, and the projection 551J of the first storage chamber 551a and the weight when viewed from the vehicle width direction Dw.
  • the rotation trajectories 631T of 631 partially overlap each other.
  • the storage portion 55 is provided so as to straddle an imaginary straight line I passing through the crankshaft center C61 and the balancer shaft 63 (that is, an imaginary straight line passing through the second imaginary line segment L2). If it does, it extends from the side of the oil pan 544 to the opposite side of the oil pan 544 with respect to the imaginary straight line I. As described above, the reservoir 55 is extended such that a part of the reservoir 55 is located in the opposite direction of the oil pan 544 with respect to the imaginary straight line I.
  • the crankcase 53 has an outer wall portion 531 that constitutes the outer wall surface thereof.
  • the wall surface of the storage portion 55 is constituted by the outer wall surface of the outer wall portion 531. That is, the outer wall portion 531 functions as a wall of the crankcase 53 and also functions as a wall of the storage portion 55. Thus, a part of the wall of the crankcase 53 and a part of the wall of the reservoir 55 are made common.
  • a space is secured on the other side Do2 of the center line Lc of the cylinder 511 by positioning the crankshaft center C61 of the crankshaft 61 on one side Do1 of the center line Lc of the cylinder 511 . Then, the upper end 55T of the reservoir 55 is disposed on the other side Do2 of the center line Lc of the cylinder 511 so as to overlap the crankshaft 61 when viewed from the offset direction Do, and this space is effectively used. By this, it is possible to suppress the enlargement of the engine 5 while securing a large storage volume of engine oil.
  • the above-mentioned engine 5 exerts such an effect effectively by utilizing the features of the dry sump method. That is, in the wet sump, the engine oil is stored in the oil pan 544 itself provided at the bottom of the crankcase 53. Therefore, a large amount of engine oil can not be stored in order to prevent the crankshaft 61 from getting soaked in the engine oil. On the other hand, since the above-mentioned engine 5 adopts the dry sump method of sending the engine oil from the oil pan to the storage portion 55, the crankshaft 61 is not immersed in the engine oil, and the engine oil is stored as described above. It is possible to secure a large volume.
  • the transmission 66 is disposed on one side Do1 from the center line Lc of the cylinder 511 in the offset direction Do. That is, the transmission 66 and the upper end 55T of the reservoir 55 are located on opposite sides of the center line Lc of the cylinder 511. Therefore, it is possible to secure the volume of the upper end 55T of the reservoir 55 without being obstructed by the arrangement space of the transmission 66.
  • a balancer shaft 63 that rotates in conjunction with the crankshaft 61 is provided between the upper end 55 T of the storage portion 55 and the crankshaft 61. That is, in the engine 5 described above, the crankshaft 61 is positioned on one side Do1 of the center line Lc of the cylinder 511, thereby securing a space on the other side Do2 of the center line Lc of the cylinder 511. Therefore, the balancer shaft 63 can be further disposed while securing the engine oil storage volume on the other side Do2 of the center line Lc of the cylinder 511.
  • the upper end 55T of the storage portion 55 has a first storage chamber 553 and a second storage chamber 554 arranged in the axial direction of the balancer shaft 63, that is, in the vehicle width direction Dw.
  • the oil is stored in each of the storage chambers 554.
  • the weight 631 of the balancer shaft 63 is located between both ends 554r and 554l of the second storage chamber 554.
  • the first storage chamber 553 has a projecting portion 553J that protrudes to the weight 631 side more than the second storage chamber 554 in the front-rear direction Dp, and a part of the projecting portion 553J is a balancer as viewed from the vehicle width direction Dw.
  • the protrusion 553J is provided in the first storage chamber 553 of the storage 55, and more engine oil can be stored while preventing interference between the storage 55 and the balancer shaft 63.
  • the storage portion 55 is extended from the side of the oil pan 544 to the opposite side of the oil pan 544 with respect to an imaginary straight line I passing through the crankshaft center C 61 and the balancer shaft 63. As a result, a large storage volume of engine oil is secured.
  • crankcase 53 has an outer wall portion 531 constituting an outer wall surface, and at least a part of the wall surface of the storage portion 55 is constituted by the outer wall surface of the outer wall portion 531.
  • the volume in the crankcase 53 is effectively utilized to ensure a wide storage volume of engine oil.
  • the engine 5 is corresponded to an example of the "engine” of this invention.
  • the cylinder 511 corresponds to an example of the "cylinder” of the present invention.
  • the crankcase 53 corresponds to an example of the “crankcase” in the present invention.
  • the outer wall 531 corresponds to an example of the “outer wall” in the present invention.
  • the crankshaft 61 corresponds to an example of the "crankshaft” of the present invention.
  • the crankshaft center C61 corresponds to an example of the "crankshaft center” in the present invention.
  • the piston 512 corresponds to an example of the "piston” of the present invention.
  • the connecting rod 62 corresponds to an example of the "connecting rod” of the present invention.
  • the oil pan 544 corresponds to an example of the "oil pan” of the present invention.
  • Storage part 55 is equivalent to an example of a "storage part” of the present invention.
  • the first storage chamber 553 corresponds to an example of the “first storage chamber” in the present invention.
  • the second storage chamber 554 corresponds to an example of the “second storage chamber” in the present invention.
  • the projecting portion 553J corresponds to an example of the "projecting portion” in the present invention.
  • the scavenge pump 91 corresponds to an example of the “scavenge pump” of the present invention.
  • the offset direction Do corresponds to an example of the “offset direction” in the present invention.
  • One side Do1 corresponds to an example of "one side” of the present invention.
  • the other side Do2 corresponds to an example of the "other side” of the present invention.
  • the balancer shaft 63 corresponds to an example of the “balancer shaft” in the present invention.
  • the weight 631 corresponds to an example of the “weight” in the present invention.
  • the rotation trajectory 631T corresponds to an example of the “rotation trajectory” in the present invention.
  • the transmission 66 corresponds to an example of the "transmission” of the present invention.
  • the motorcycle 1 corresponds to an example of the "vehicle” in the present invention.
  • the front wheel 34 and the rear wheel 37 correspond to an example of the "wheel” of the present invention.
  • the present invention is not limited to the above-described embodiment, and various modifications can be made other than the above without departing from the scope of the invention.
  • the configuration of the storage unit 55 may be changed as appropriate. Specifically, it is not necessary to provide the partition 555 between the first storage chamber 553 and the second storage chamber 554, and it is not always necessary to provide the projection 553J.
  • the degree of overlapping the storage portion 55 or the storage chamber 551 with the crankshaft 61 may be changed as appropriate, and the balancer shaft 63 needs to be disposed between the upper end portion 55T of the storage portion 55 and the crankshaft 61 There is not.
  • the single-cylinder engine 5 having the single cylinder 511 in the cylinder block 51 is illustrated.
  • the number of cylinders 511 provided in the engine 5 is not limited to one, and may be two or more.
  • the intake and exhaust valve mechanism provided in the engine 5 is not limited to the above-described DOHC, and may be another mechanism such as SOHC (Single Over Head Camshaft).
  • the drive system of the intake valve 523 and the exhaust valve 527 is not limited to the above-described direct acting system, and other systems such as a rocker arm system may be used.
  • the posture of the cylinder 511 is not limited to the above-described backward inclination, and may be forward inclination or upright.
  • crankcase 53 may be changed as appropriate. Therefore, for example, it is not necessary to integrally provide the storage unit 55.
  • the position or angle at which the engine 5 is attached to the vehicle body frame 2 is not limited to the above example, and can be changed as appropriate.
  • the present invention can be applied to all engines using engine oil and vehicles equipped with such engines.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Lubrication Of Internal Combustion Engines (AREA)
  • Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)

Abstract

Provided is an engine in which a crankshaft 61 is positioned further toward one side Do1 than the center line Lc of a cylinder 511 and a space is thereby maintained on the other side Do2 of the center line Lc of the cylinder 511. In addition, the space is used effectively by arranging the upper end 55T of a reservoir section 55 on the other side Do2 of the center line Lc of the cylinder 511 so as to overlap with the crankshaft 61 when viewed from an offset direction Do. As a result, it is possible to maintain a wide engine oil storage volume while minimizing increases in the size of the engine 5.

Description

エンジン、車両Engine, vehicle
 この発明は、エンジンの各部に供給されるオイルを貯留する技術に関する。 The present invention relates to a technology for storing oil supplied to each part of an engine.
 従来、エンジンはその内部を循環するオイルにより潤滑、冷却および洗浄等を行って、正常な動作を実現している。また、オイルを循環する方式としては、ウェットサンプ方式とドライサンプ方式とが存在する。例えば特許文献1では、ドライサンプ方式を採用したエンジンが記載されている。このエンジンでは、クランクケースの底部に落下してきたオイルが、スカベンジポンプにより吸い上げられてオイル貯留室に貯留される。そして、フィードポンプがオイル貯留室からエンジン内部の各部品にオイルを供給する。 Heretofore, the engine has been lubricated, cooled, washed, etc. by the oil circulating inside to realize a normal operation. Further, as a method of circulating oil, there are a wet sump method and a dry sump method. For example, Patent Document 1 describes an engine employing a dry sump method. In this engine, the oil dropped to the bottom of the crankcase is sucked up by the scavenge pump and stored in the oil storage chamber. And a feed pump supplies oil to each part inside the engine from the oil storage chamber.
特許第5330052号公報Patent No. 5330052
 ところで、ウェットサンプ方式およびドライサンプ方式のいずれにおいても、オイル不足によるエンジンの不良動作の発生を確実に防止するためには、十分な量のオイルをエンジンに貯留しておくことが求められる。しかしながら、オイルの貯留容積を広く確保しようとすると、エンジンが大型化してしまうという問題があった。 Incidentally, in any of the wet sump method and the dry sump method, in order to reliably prevent the occurrence of the defective operation of the engine due to the lack of oil, it is required to store a sufficient amount of oil in the engine. However, in order to secure a large oil storage volume, there has been a problem that the size of the engine is increased.
 この発明は、上記課題に鑑みなされたものであり、オイルの貯留容積を広く確保しつつエンジンの大型化を抑制することを可能とする技術の提供を目的とする。 This invention is made in view of the said subject, and aims at provision of the technique which makes it possible to suppress the enlargement of an engine, ensuring the storage volume of oil widely.
 本発明に係るエンジンは、シリンダーと、シリンダーに接続されたクランクケースと、 少なくともその一部がクランクケース内に配置され、シリンダー内を往復移動するピストンにコネクティングロッドを介して接続され、ピストンの往復運動に連動してクランク軸心を中心に回転するクランク軸と、クランクケース内に設けられたオイルパンと、クランクケース内に設けられ、オイルを貯留する貯留部と、オイルパンから貯留部にオイルを送るスカベンジポンプとを備え、シリンダーの中心線およびクランク軸心のそれぞれに直交するオフセット方向において、クランク軸心はシリンダーの中心線より一方側に位置し、貯留部の少なくとも一部は、オフセット方向においてシリンダーの中心線の他方側に位置し、オフセット方向から見てクランク軸と重なる。 The engine according to the present invention comprises a cylinder, a crankcase connected to the cylinder, and at least a part of which is disposed in the crankcase and connected via a connecting rod to a piston reciprocating in the cylinder via the connecting rod. A crankshaft that rotates around a crankshaft in conjunction with movement, an oil pan provided in the crankcase, a reservoir for storing oil, and an oil pan from the oil pan to the reservoir are provided in the crankcase The crankshaft center is located on one side of the cylinder centerline in offset directions orthogonal to the cylinder centerline and the crankshaft center respectively, and at least a portion of the reservoir is in the offset direction. Located on the other side of the center line of the cylinder at It overlaps with the crank shaft.
 このように構成された本発明では、クランク軸心をシリンダーの中心線より一方側に位置させることで、シリンダーの中心線の他方側にスペースを確保している。そして、貯留部の少なくとも一部を、オフセット方向から見てクランク軸に重なるようにシリンダーの中心線の他方側に配置して、このスペースを有効活用している。これによって、オイルの貯留容積を広く確保しつつエンジンの大型化を抑制することが可能となっている。 In the present invention configured as described above, the crankshaft is positioned on one side of the center line of the cylinder, thereby securing a space on the other side of the center line of the cylinder. Then, at least a part of the storage portion is disposed on the other side of the center line of the cylinder so as to overlap the crankshaft as viewed from the offset direction, and this space is effectively used. By this, it is possible to suppress the enlargement of the engine while securing a large storage volume of oil.
 さらに言えば、本発明は、ドライサンプ方式の特徴を活用することで、かかる効果を効果的に奏している。つまり、ウェットサンプでは、クランクケースの底に設けられたオイルパンそのものにオイルを貯留する。したがって、クランク軸がオイルに漬かるのを避けるために、多くのオイルを貯留することができない。これに対して、本発明は、オイルパンから貯留部にオイルを送るドライサンプ方式を採用しているため、クランク軸がオイルに漬かることなく、上述のようにオイルの貯留容積を広く確保することが可能となっている。 Furthermore, the present invention exhibits such an effect effectively by utilizing the features of the dry sump method. That is, in the wet sump, the oil is stored in the oil pan itself provided at the bottom of the crankcase. Therefore, a large amount of oil can not be stored to prevent the crankshaft from getting soaked in the oil. On the other hand, since the present invention adopts the dry sump method of sending the oil from the oil pan to the storage portion, the oil storage volume can be widely secured as described above without the crankshaft being soaked in the oil. It is possible.
 また、クランクケース内に配置されるトランスミッションをさらに備え、トランスミッションは、オフセット方向においてシリンダーの中心線より一方側に位置するように、エンジンを構成しても良い。かかる構成では、トランスミッションと貯留部の少なくとも一部とはシリンダーの中心線を挟んで反対側に位置する。したがって、貯留部の少なくとも一部を、トランスミッションの配置スペースに妨げられることなく確保することが可能となる。 Further, the engine may be configured to further include a transmission disposed in the crankcase, and the transmission is positioned on one side of the center line of the cylinder in the offset direction. In such a configuration, the transmission and at least a portion of the reservoir are located on opposite sides of the center line of the cylinder. Therefore, it is possible to secure at least a part of the reservoir without being obstructed by the space for arranging the transmission.
 また、貯留部の少なくとも一部とクランク軸との間に、クランク軸に連動して回転するバランサ軸をさらに備えるように、エンジンを構成しても良い。つまり、本発明では、クランク軸をシリンダーの中心線より一方側に位置させることで、シリンダーの中心線の他方側にスペースを確保している。したがって、シリンダーの中心線の他方側にオイルの貯留容積を確保しつつ、さらにバランサ軸を配置することができる。 In addition, the engine may be configured to further include a balancer shaft that rotates in conjunction with the crankshaft between at least a part of the storage portion and the crankshaft. That is, in the present invention, a space is secured on the other side of the center line of the cylinder by positioning the crankshaft on one side of the center line of the cylinder. Therefore, the balancer shaft can be further disposed while securing the oil storage volume on the other side of the center line of the cylinder.
 また、貯留部の少なくとも一部は、バランサ軸の軸方向に配列された第1貯留室および第2貯留室を有し、第1貯留室および第2貯留室それぞれの内部にオイルを貯留し、バランサ軸の軸方向において、バランサ軸のウェイトは、第2貯留室の両端の間に位置し、第1貯留室は、バランサ軸の軸方向に垂直な垂直方向に第2貯留室よりもバランサ軸側に突出する突出部を有し、突出部の少なくとも一部は、バランサ軸の軸方向から見て、バランサ軸のウェイトの回転軌跡と重なるように、エンジンを構成しても良い。かかる構成では、貯留部の第1貯留室に突出部が設けられており、より多くのオイルを、貯留部とバランサ軸との干渉を防止しつつ貯留することができる。 Further, at least a portion of the storage portion has a first storage chamber and a second storage chamber arranged in the axial direction of the balancer shaft, and stores oil in the first storage chamber and the second storage chamber, In the axial direction of the balancer shaft, the weight of the balancer shaft is located between both ends of the second storage chamber, and the first storage chamber is the balancer shaft in the vertical direction perpendicular to the axial direction of the balancer shaft than the second storage chamber. The engine may be configured to have a protruding portion that protrudes to the side, and at least a portion of the protruding portion overlaps the rotation trajectory of the weight of the balancer shaft when viewed from the axial direction of the balancer shaft. In this configuration, the protrusion is provided in the first storage chamber of the storage unit, and more oil can be stored while preventing interference between the storage unit and the balancer shaft.
 また、貯留部の少なくとも一部は、バランサ軸の軸方向から見て、クランク軸心とバランサ軸の回転中心とを通る直線に対してオイルパンとは反対の方向に位置するように、記載のエンジンを構成しても良い。かかる構成は、オイルの貯留容積を広く確保するのに資する。 In addition, at least a portion of the storage portion is described so as to be located in a direction opposite to the oil pan with respect to a straight line passing through the crankshaft center and the rotation center of the balancer shaft when viewed from the axial direction of the balancer shaft You may configure an engine. Such a configuration contributes to securing a large oil storage volume.
 また、クランクケースは、外壁面を構成する外壁部を有し、貯留部の壁面の少なくとも一部は、外壁部の外壁面により構成されるように、エンジンを構成しても良い。これによって、クランクケース内の容積を有効に活用して、オイルの貯留容積を広く確保することができる。 The crankcase may have an outer wall portion constituting an outer wall surface, and the engine may be configured such that at least a part of the wall surface of the storage portion is constituted by the outer wall surface of the outer wall portion. As a result, the volume in the crankcase can be effectively utilized to secure a large oil storage volume.
 本発明に係る車両は、上記のエンジンと、エンジンにより駆動される車輪とを備える。したがって、オイルの貯留容積を広く確保しつつエンジンの大型化を抑制することが可能となっている。 A vehicle according to the present invention includes the above engine and wheels driven by the engine. Therefore, it is possible to suppress the enlargement of the engine while securing a large storage volume of oil.
 この発明では、オイルの貯留容積を広く確保しつつエンジンの大型化を抑制することが可能となっている。 In the present invention, it is possible to suppress the size increase of the engine while securing a large oil storage volume.
本発明に係るエンジンを搭載した鞍乗型車両の一例である自動二輪車を示す側面図。FIG. 1 is a side view showing a motorcycle which is an example of a straddle-type vehicle equipped with an engine according to the present invention. エンジンの内部構成を略中心断面で示す部分断面図。The fragmentary sectional view which shows the internal structure of an engine by a substantially center cross section. エンジンの内部構成を図2よりも外側の断面で示す部分断面図。The fragmentary sectional view which shows the internal structure of an engine by the cross section outside FIG. 図3に示すIV-IV切り出し線に沿ったエンジンの部分断面図。FIG. 4 is a partial cross-sectional view of the engine along the IV-IV cut line shown in FIG. 3; エンジンが備えるオイル循環系の一例を示すブロック図。The block diagram showing an example of the oil circulation system with which an engine is provided. オフセット方向の他方側から一方側を向いて見た貯留部およびクランク軸の配置を示す図。The figure which shows arrangement | positioning of the storage part seen from the other side of an offset direction toward one side, and a crankshaft. 貯留部、クランク軸およびバランサ軸の配置を示す部分断面図。The fragmentary sectional view which shows arrangement of a storage part, a crankshaft, and a balancer shaft.
 図1は本発明に係るエンジンを搭載した鞍乗型車両の一例である自動二輪車を示す側面図である。同図に示す自動二輪車1は所謂オフロードタイプであるが、鞍乗型車両には、当該タイプ以外に、オンロードタイプ、スクータータイプ、または所謂モペットタイプの自動二輪車等も含まれる。また、本発明に係る車両には、鞍乗型車両のみならず、ATV(All Terrain Vehicle)および四輪バギー等が含まれる。 FIG. 1 is a side view showing a motorcycle which is an example of a straddle-type vehicle equipped with an engine according to the present invention. The motorcycle 1 shown in the figure is a so-called off-road type, but the straddle-type vehicle also includes an on-road type, a scooter type, or a so-called moped type motorcycle and the like besides the type. The vehicle according to the present invention includes not only straddle type vehicles but also ATVs (All Terrain Vehicles) and four-wheeled buggies.
 本明細書では、前、後、左、右とは、シート10に着座した乗員から見た前、後、左、右をそれぞれ意味するものとする。また、前後方向Dp、前後方向Dpの前側Df、前後方向Dpの後側Db、車幅方向Dwおよび鉛直方向Dvを適宜示す。前後方向Dpおよび車幅方向Dwはいずれも水平な方向であり、前後方向Dp、車幅方向Dwおよび鉛直方向Dvは互いに直交する。 In the present specification, front, rear, left and right mean front, rear, left and right as viewed from the occupant seated on the seat 10 respectively. Also, the front and rear directions Dp, the front side Df in the front and rear directions Dp, the rear side Db in the front and rear directions Dp, the vehicle width direction Dw, and the vertical direction Dv are appropriately shown. The longitudinal direction Dp and the vehicle width direction Dw are both horizontal directions, and the longitudinal direction Dp, the vehicle width direction Dw and the vertical direction Dv are orthogonal to each other.
 自動二輪車1は、車体フレーム2を備える。車体フレーム2は、ヘッドパイプ21、メインフレーム22、タンクレール23、シートレール24、バックステー25およびダウンフレーム26等で構成される。ヘッドパイプ21は車体フレーム2の前側Df端部に配置され、メインフレーム22はヘッドパイプ21から後側Dbへ延びつつ下方へ屈曲する。タンクレール23は、ヘッドパイプ21とタンクレール23との間に配置され、タンクレール23に燃料タンク31が取り付けられている。シートレール24はメインフレーム22から後側Dbに延設され、シートレール24にシート10が取り付けられている。このシートレール24の後側Db端部はバックステー25によってメインフレーム22に接続されている。また、ダウンフレーム26はヘッドパイプ21から下方に延びつつ後側Dbに屈曲し、ダウンフレーム26とメインフレーム22とのそれぞれの後側Db端部が接続されている。 The motorcycle 1 includes a vehicle body frame 2. The vehicle body frame 2 includes a head pipe 21, a main frame 22, a tank rail 23, a seat rail 24, a back stay 25, a down frame 26, and the like. The head pipe 21 is disposed at the front end Df end of the vehicle body frame 2, and the main frame 22 bends downward while extending from the head pipe 21 to the rear side Db. The tank rail 23 is disposed between the head pipe 21 and the tank rail 23, and the fuel tank 31 is attached to the tank rail 23. The seat rail 24 extends from the main frame 22 to the rear side Db, and the seat 10 is attached to the seat rail 24. The rear Db end of the seat rail 24 is connected to the main frame 22 by a back stay 25. The down frame 26 extends downward from the head pipe 21 and is bent to the rear side Db, and the rear side Db ends of the down frame 26 and the main frame 22 are connected.
 ヘッドパイプ21には、図示しないステアリングシャフトが回転可能に挿入され、ステアリングシャフトの上端部にハンドル32が取り付けられている。また、ステアリングシャフトには、前側Dfへ向かって斜め下方に延設されたフロントフォーク33が取り付けられ、フロントフォーク33の下端部に前輪34が回転可能に取り付けられている。 A steering shaft (not shown) is rotatably inserted into the head pipe 21 and a handle 32 is attached to the upper end of the steering shaft. Further, a front fork 33 extending obliquely downward toward the front side Df is attached to the steering shaft, and a front wheel 34 is rotatably attached to a lower end portion of the front fork 33.
 メインフレーム22の後側Db端部には、ピボット軸221が取り付けられており、ピボット軸221から後側Dbにリアアーム35が延設されている。このリアアーム35は、ピボット軸221を中心にして上下方向(鉛直方向Dv)に揺動可能にピボット軸221に支持された状態で、リアサスペンション36を介してメインフレーム22に取り付けられている。そして、リアアーム35の後側Db端部に後輪37が回転可能に取り付けられている。 A pivot shaft 221 is attached to the rear Db end of the main frame 22, and a rear arm 35 is extended from the pivot shaft 221 to the rear Db. The rear arm 35 is attached to the main frame 22 via the rear suspension 36 in a state of being supported by the pivot shaft 221 so as to be pivotable in the vertical direction (vertical direction Dv) about the pivot shaft 221. A rear wheel 37 is rotatably attached to the rear Db end of the rear arm 35.
 エンジン5は、メインフレーム22とダウンフレーム26に囲まれた領域で車体フレーム2に装着されている。そして、エンジン5が不図示の二次減速機構を介して後輪37を回転駆動する。なお、二次減速機構は、チェーンドライブ式、シャフトドライブ式およびベルトドライブ式のいずれでも構わない。 The engine 5 is mounted to the vehicle body frame 2 in a region surrounded by the main frame 22 and the down frame 26. Then, the engine 5 rotationally drives the rear wheel 37 via a secondary reduction mechanism (not shown). The secondary reduction mechanism may be any of a chain drive type, a shaft drive type and a belt drive type.
 図2はエンジンの内部構成を略中心断面で示す部分断面図であり、図3はエンジンの内部構成を図2よりも外側の断面で示す部分断面図であり、図4は図3に示すIV-IV切り出し線に沿ったエンジンの部分断面図である。エンジン5は、シリンダーブロック51と、シリンダーブロック51の上端に取り付けられたシリンダーヘッド52と、シリンダーブロック51の下端に取り付けられたクランクケース53とを備える。シリンダーブロック51には、シリンダーヘッド52との当接面であるヘッド合面51aが形成されている。一方、シリンダーヘッド52には、シリンダーブロック51との当接面であるシリンダー合面52aが形成されている。そして、シリンダーブロック51のヘッド合面51aとシリンダーヘッド52のシリンダー合面52aとが当接した状態で、シリンダーブロック51とシリンダーヘッド52とが互いに取り付けられる。また、シリンダーブロック51の外周面にはフランジ51bが形成されており、クランクケース53との当接面であるクランク合面51cがフランジ51bに形成されている。一方、クランクケース53には、シリンダーブロック51との当接面であるシリンダー合面53cが形成されている。そして、シリンダーブロック51のクランク合面51cとクランクケース53のシリンダー合面53cとが当接した状態で。シリンダーブロック51とクランクケース53とが互いに取り付けられる。 FIG. 2 is a partial cross-sectional view showing the internal configuration of the engine in a substantially central cross section, FIG. 3 is a partial cross-sectional view showing the internal configuration of the engine in a cross section outside FIG. FIG. 4 is a partial cross-sectional view of the engine along the IV cut line. The engine 5 includes a cylinder block 51, a cylinder head 52 attached to the upper end of the cylinder block 51, and a crankcase 53 attached to the lower end of the cylinder block 51. The cylinder block 51 is formed with a head mating surface 51 a that is a contact surface with the cylinder head 52. On the other hand, in the cylinder head 52, a cylinder mating surface 52a which is a contact surface with the cylinder block 51 is formed. Then, the cylinder block 51 and the cylinder head 52 are attached to each other in a state where the head joint surface 51a of the cylinder block 51 and the cylinder joint surface 52a of the cylinder head 52 are in contact with each other. Further, a flange 51 b is formed on the outer peripheral surface of the cylinder block 51, and a crank mating surface 51 c which is a contact surface with the crank case 53 is formed on the flange 51 b. On the other hand, in the crankcase 53, a cylinder mating surface 53c which is a contact surface with the cylinder block 51 is formed. Then, in a state where the crank mating surface 51 c of the cylinder block 51 and the cylinder mating surface 53 c of the crank case 53 are in contact with each other. The cylinder block 51 and the crankcase 53 are attached to each other.
 エンジン5は、単一のシリンダー511をシリンダーブロック51に備えた単気筒型である。シリンダー511内にはピストン512が配置されており、ピストン512はシリンダー511内を往復移動することができる。このシリンダー511は後傾に配置されている。つまり、シリンダー511の中心線Lcは鉛直方向Dvに対して後側Dbに傾いており、換言すれば、シリンダー511の中心線Lcは上側に行くにつれて後側Dbに傾斜する。ここで、シリンダー511の中心線Lcは、シリンダー511内のボアの中心を通ってピストン512のストロークの方向に平行な仮想直線として例えば求めることができる。 The engine 5 is a single cylinder type in which a single cylinder 511 is provided in a cylinder block 51. A piston 512 is disposed in the cylinder 511, and the piston 512 can reciprocate in the cylinder 511. The cylinder 511 is disposed rearward. That is, the center line Lc of the cylinder 511 is inclined to the rear side Db with respect to the vertical direction Dv, in other words, the center line Lc of the cylinder 511 is inclined to the rear side Db as it goes upward. Here, the center line Lc of the cylinder 511 can be determined, for example, as a virtual straight line parallel to the direction of the stroke of the piston 512 through the center of the bore in the cylinder 511.
 シリンダーヘッド52は、ピストン512の上端面との間の燃焼室に連通する吸気ポート522と、燃焼室に対して吸気ポート522を開閉する吸気バルブ523とを有する。吸気バルブ523は、吸気ポート522を閉じる位置にバルブスプリング524によって付勢されている。そして、吸気バルブ523の上端に当接するカムシャフト525を回転させることで、吸気バルブ523を開閉することができる。また、シリンダーヘッド52は、燃焼室に連通する排気ポート526と、燃焼室に対して排気ポート526を開閉する排気バルブ527とを有する。排気バルブ527は、排気ポート526を閉じる位置にバルブスプリング528によって付勢されている。そして、排気バルブ527の上端に当接するカムシャフト529を回転させることで、排気バルブ527を開閉することができる。このようにエンジン5は、吸気側および排気側のそれぞれにカムシャフト525、529を備えた、DOHC(Double Over Head Camshaft)型の吸排気バルブ機構を備える。また、エンジン5は、吸気バルブ523および排気バルブ527をそれぞれ複数(2個)設けたマルチバルブ機構を備える。 The cylinder head 52 has an intake port 522 communicating with the combustion chamber between the upper end surface of the piston 512 and an intake valve 523 opening and closing the intake port 522 with respect to the combustion chamber. The intake valve 523 is biased by a valve spring 524 to a position where the intake port 522 is closed. The intake valve 523 can be opened and closed by rotating the cam shaft 525 in contact with the upper end of the intake valve 523. The cylinder head 52 also has an exhaust port 526 in communication with the combustion chamber, and an exhaust valve 527 for opening and closing the exhaust port 526 relative to the combustion chamber. The exhaust valve 527 is biased by a valve spring 528 to a position where the exhaust port 526 is closed. Then, the exhaust valve 527 can be opened and closed by rotating the cam shaft 529 in contact with the upper end of the exhaust valve 527. Thus, the engine 5 is provided with a DOHC (Double Over Head Camshaft) type intake and exhaust valve mechanism provided with camshafts 525 and 529 on the intake side and the exhaust side, respectively. In addition, the engine 5 includes a multi-valve mechanism provided with a plurality (two) of intake valves 523 and exhaust valves 527 respectively.
 クランクケース53は、エンジン5の機械的構成を収容する収容部54と、エンジン5内を循環するエンジンオイルを貯留する貯留部55(オイルタンク)とを有し、収容部54と貯留部55とは隔壁56によって区分けされている。さらに、収容部54は、クランク室541を内部に有する。 The crankcase 53 has a storage portion 54 for storing the mechanical configuration of the engine 5 and a storage portion 55 (oil tank) for storing engine oil circulating in the engine 5, and the storage portion 54 and the storage portion 55 Are separated by a partition 56. Furthermore, the housing portion 54 has a crank chamber 541 inside.
 クランク室541はシリンダー511に連通しており、車幅方向Dwに平行に配置されたクランク軸61を収容する。このクランク軸61は、車幅方向Dwに平行なクランク軸心C61を中心に回転可能にクランクケース53に支持されたクランクジャーナル611と、クランク軸心C61に対して偏心するクランクピン612とを有する。クランクピン612は、コネクティングロッド62によってピストン512に接続されており、クランク軸61は、ピストン512の往復運動に連動してクランク軸心C61を中心に回転する。また、クランク軸61は、クランク軸心C61に対してクランクピン612の反対側に偏心するカウンターウェイト613を有し、カウンターウェイト613によって振動の抑制を図っている。 The crank chamber 541 is in communication with the cylinder 511, and accommodates the crankshaft 61 disposed parallel to the vehicle width direction Dw. The crankshaft 61 has a crank journal 611 rotatably supported by the crankcase 53 around a crankshaft center C61 parallel to the vehicle width direction Dw, and a crank pin 612 eccentric to the crankshaft center C61. . The crank pin 612 is connected to the piston 512 by a connecting rod 62, and the crankshaft 61 rotates around a crankshaft center C61 in conjunction with the reciprocating motion of the piston 512. In addition, the crankshaft 61 has a counterweight 613 eccentrically located on the opposite side of the crankpin 612 with respect to the crankshaft center C61, and the counterweight 613 is intended to suppress the vibration.
 また、クランク室541は、車幅方向Dwに平行に配置されたバランサ軸63を収容する。このバランサ軸63は、車幅方向Dwに平行なバランサ軸心C63を中心に回転可能にクランクケース53に支持されており、バランサ軸心C63に対して偏心するウェイト631を有する。そして、バランサ軸63は、クランク軸61の回転に連動して回転することで、クランク軸61の振動を抑制する。 Further, the crank chamber 541 accommodates the balancer shaft 63 disposed in parallel to the vehicle width direction Dw. The balancer shaft 63 is rotatably supported by the crankcase 53 about a balancer axial center C63 parallel to the vehicle width direction Dw, and has a weight 631 eccentric to the balancer axial center C63. The balancer shaft 63 rotates in conjunction with the rotation of the crankshaft 61 to suppress the vibration of the crankshaft 61.
 つまり、クランク軸61には、プライマリードライブギア614が同軸上に取り付けられており、プライマリードライブギア614はクランク軸61とともにクランク軸心C61を中心に回転する。一方、バランサ軸63には、バランサギア632が同軸上に取り付けられており、バランサ軸63はバランサギア632とともにバランサ軸心C63を中心に回転する。そして、プライマリードライブギア614とバランサギア632とが相互に係合しており、クランク軸61の回転を減速してバランサ軸63に伝達する。 That is, the primary drive gear 614 is coaxially attached to the crankshaft 61, and the primary drive gear 614 rotates around the crankshaft center C61 together with the crankshaft 61. On the other hand, a balancer gear 632 is coaxially attached to the balancer shaft 63, and the balancer shaft 63 rotates with the balancer gear 632 around a balancer axial center C63. The primary drive gear 614 and the balancer gear 632 are engaged with each other, reduce the rotation of the crankshaft 61 and transmit it to the balancer shaft 63.
 また、エンジン5は、クランク軸61の回転運動から発電を行う発電機64を備える。この発電機64は、フライホイール641と、フライホイール641の内側に配置されたステーターコイル642とを有する。フライホイール641は、クランク軸61に対して同軸上に取り付けられて、クランク軸心C61を中心にクランク軸61とともに回転可能である。このフライホイール641では、N極の磁石とS極の磁石とが交互に並んで、ステーターコイル642を外側から取り囲む。そして、発電機64は、フライホイール641の回転に伴って生じる磁石とステーターコイル642との間の電磁誘導によって発電を行う。 The engine 5 also includes a generator 64 that generates electric power from the rotational motion of the crankshaft 61. The generator 64 has a flywheel 641 and a stator coil 642 disposed inside the flywheel 641. The flywheel 641 is coaxially attached to the crankshaft 61 and is rotatable with the crankshaft 61 about a crankshaft center C61. In the flywheel 641, the N pole magnet and the S pole magnet are alternately arranged to surround the stator coil 642 from the outside. Then, the generator 64 generates electric power by electromagnetic induction between the magnet and the stator coil 642 generated as the flywheel 641 rotates.
 さらに、クランク室541は、クラッチ機構65とトランスミッション66とを収容する。図4に示すように、クランクケース53の車幅方向Dwの端部は、クラッチ機構65を覆うクラッチボックス532となっており、シリンダー511より車幅方向Dwに突き出ている。クラッチ機構65は、車幅方向Dwに平行なメイン軸心C67を中心に回転可能なクラッチハウジング651を有し、クラッチハウジング651の外周には、メイン軸心C65を中心とするプライマリードリブンギア652が設けられている。そして、プライマリードライブギア614とプライマリードリブンギア652とが互いに係合しており、クランク軸61の回転を減速してクラッチハウジング651に伝達する一次減速機構を構成する。 Further, the crank chamber 541 accommodates the clutch mechanism 65 and the transmission 66. As shown in FIG. 4, an end of the crankcase 53 in the vehicle width direction Dw is a clutch box 532 that covers the clutch mechanism 65, and protrudes from the cylinder 511 in the vehicle width direction Dw. The clutch mechanism 65 has a clutch housing 651 rotatable around a main axial center C67 parallel to the vehicle width direction Dw, and on the outer periphery of the clutch housing 651 is a primary driven gear 652 centered on the main axial center C65. It is provided. The primary drive gear 614 and the primary driven gear 652 are engaged with each other to configure a primary reduction mechanism that decelerates the rotation of the crankshaft 61 and transmits it to the clutch housing 651.
 また、クラッチ機構65では、メイン軸心C67を中心に回転可能なクラッチボス653が、クラッチハウジング651の内側に配置されており、クラッチハウジング651とともに回転するフリクションプレート654と、クラッチボス653とともに回転するクラッチプレート655とが交互に並んでいる。さらに、クラッチ機構65はクラッチスプリングの弾性力によってクラッチボス653へ向けて付勢されたプレッシャー部656を有する。そして、クラッチ機構65は、プレッシャー部656によってフリクションプレート654とクラッチプレート655とをクラッチボス653に押圧することでクラッチハウジング651の回転をクラッチボス653に伝達できる。あるいは、クラッチ機構65は、クラッチスプリングの弾性力に抗してプレッシャー部656をクラッチボス653の逆側へ移動させることで、クラッチハウジング651からクラッチボス653への回転の伝達を遮断できる。 Further, in the clutch mechanism 65, the clutch boss 653 rotatable around the main axial center C67 is disposed inside the clutch housing 651, and rotates together with the friction plate 654 that rotates with the clutch housing 651 and the clutch boss 653. The clutch plates 655 are alternately arranged. Further, the clutch mechanism 65 has a pressure portion 656 biased toward the clutch boss 653 by the elastic force of the clutch spring. The clutch mechanism 65 can transmit the rotation of the clutch housing 651 to the clutch boss 653 by pressing the friction plate 654 and the clutch plate 655 to the clutch boss 653 by the pressure portion 656. Alternatively, the clutch mechanism 65 can interrupt the transmission of the rotation from the clutch housing 651 to the clutch boss 653 by moving the pressure portion 656 to the opposite side of the clutch boss 653 against the elastic force of the clutch spring.
 そして、クラッチボス653に、トランスミッション66のメイン軸67が取り付けられている。したがって、クラッチ機構65は、クランク軸61からメイン軸67へ動力を伝達する伝達動作と、クランク軸61からメイン軸67への動力の伝達を遮断する遮断動作とを選択的に実行できる。 The main shaft 67 of the transmission 66 is attached to the clutch boss 653. Therefore, the clutch mechanism 65 can selectively execute the transmission operation of transmitting power from the crankshaft 61 to the main shaft 67 and the blocking operation of blocking transmission of power from the crankshaft 61 to the main shaft 67.
 トランスミッション66は、それぞれ車幅方向Dwに平行に配置されたメイン軸67およびドライブ軸68を有する。メイン軸67は、メイン軸心C67を中心に回転可能にクランクケース53に支持され、ドライブ軸68は、車幅方向Dwに平行なドライブ軸心C68を中心に回転可能にクランクケース53に支持されている。このメイン軸67には、トランスミッション66の一部を構成する複数のギア671が設けられている。したがって、複数のギア671を含めたメイン軸67の重量は一般的に上述のバランサ軸63よりも重い。メイン軸67には、さらにギア671をメイン軸67の軸方向(車幅方向Dw)にスライドさせるシフトフォーク672が設けられている。また、ドライブ軸68には、複数のギア681と、ギア681をドライブ軸68の軸方向(車幅方向Dw)にスライドさせるシフトフォーク682とが設けられている。これらシフトフォーク672、682に対しては、運転者の操作に応じて回転するシフトドラム661が設けられており、シフトフォーク672、682のそれぞれはシフトドラム661の回転角度に応じた位置に対応するギア671、681を移動させる。こうして、トランスミッション66は、運転者の操作に応じた変速比でメイン軸67の回転をドライブ軸68に伝達する。そして、このドライブ軸68の回転が二次減速機構によって後輪37に伝達される。 The transmission 66 has a main shaft 67 and a drive shaft 68 arranged parallel to the vehicle width direction Dw. The main shaft 67 is rotatably supported by the crankcase 53 around a main axial center C67, and the drive shaft 68 is rotatably supported by the crankcase 53 around a drive axial center C68 parallel to the vehicle width direction Dw. ing. The main shaft 67 is provided with a plurality of gears 671 that constitute a part of the transmission 66. Therefore, the weight of the main shaft 67 including the plurality of gears 671 is generally heavier than the balancer shaft 63 described above. The main shaft 67 is further provided with a shift fork 672 for sliding the gear 671 in the axial direction of the main shaft 67 (in the vehicle width direction Dw). Further, the drive shaft 68 is provided with a plurality of gears 681 and a shift fork 682 for sliding the gears 681 in the axial direction of the drive shaft 68 (in the vehicle width direction Dw). The shift forks 672 and 682 are provided with shift drums 661 that rotate according to the operation of the driver, and each of the shift forks 672 and 682 corresponds to a position according to the rotation angle of the shift drum 661 Move gears 671, 681. Thus, the transmission 66 transmits the rotation of the main shaft 67 to the drive shaft 68 at a gear ratio according to the driver's operation. Then, the rotation of the drive shaft 68 is transmitted to the rear wheel 37 by the secondary reduction mechanism.
 ちなみに、上述のとおり、クランク室541には、エンジンオイルが循環的に供給される。そして、クランク室541の底部は、自重で落下してきたエンジンオイルを受け止めるオイルパン544として機能する。 Incidentally, as described above, engine oil is cyclically supplied to the crank chamber 541. The bottom of the crank chamber 541 functions as an oil pan 544 for receiving engine oil that has fallen by its own weight.
 貯留部55は、その内部の貯留室551にエンジンオイルを貯留する。この貯留室551は、クランク室541の前側Dfに配置され、前側Dfからの正面視においてクランク室541と少なくとも部分的に重なる。エンジンオイルは、鉱物性オイル、化学合成オイルあるいは部分化学合成オイル等のベースオイルに添加剤を加えた組成を有し、ポンプ(スカベンジポンプ、フィードポンプ)によってエンジン5内を循環する。このポンプの駆動は、クランク軸61の回転を利用して実行される。つまり、ポンプには、プライマリードライブギア614と係合するポンプギア(図示省略)が同軸上に取り付けられており、プライマリードライブギア614およびポンプギアがクランク軸61の回転をポンプに伝達する。 The storage unit 55 stores engine oil in a storage chamber 551 inside thereof. The storage chamber 551 is disposed on the front side Df of the crank chamber 541 and at least partially overlaps the crank chamber 541 in a front view from the front side Df. The engine oil has a composition in which an additive is added to a base oil such as mineral oil, chemically synthesized oil or partially chemically synthesized oil, and is circulated in the engine 5 by a pump (scavenge pump, feed pump). The drive of the pump is performed using the rotation of the crankshaft 61. That is, a pump gear (not shown) engaged with the primary drive gear 614 is coaxially attached to the pump, and the primary drive gear 614 and the pump gear transmit the rotation of the crankshaft 61 to the pump.
 ここで、図2に示すクランク軸61の軸方向(つまり、車幅方向Dw)からの側面視におけるエンジン5内のレイアウトについて詳述しておく。クランク軸61、バランサ軸63、メイン軸67およびドライブ軸68は互いに平行に配置されている。そして、図2に示すように、クランク軸61は、シリンダー511の中心線Lcに対して後方にオフセットして配置されている。つまり、クランク軸61のクランク軸心C61を端としてシリンダー511の中心線Lcに平行にシリンダー511側に延びる仮想半直線Lhは、シリンダー511の中心線Lcより後方に位置する。別の見方をすると、シリンダー511の中心線Lcおよびクランク軸心C61のそれぞれに垂直なオフセット方向Doにおいて、シリンダー511の中心線Lcが、仮想半直線Lhよりもバランサ軸63側に位置している。このように、クランク軸心C61(あるいは仮想半直線Lh)は、シリンダー511の中心線Lcよりオフセット方向Doの一方側Do1に位置しており、バランサ軸63は、シリンダー511の中心線Lcよりオフセット方向Doの他方側Do2に位置している。ここで、他方側Do2は、一方側Do1の逆側である。 Here, the layout in the engine 5 in a side view from the axial direction of the crankshaft 61 (that is, the vehicle width direction Dw) shown in FIG. 2 will be described in detail. The crankshaft 61, the balancer shaft 63, the main shaft 67, and the drive shaft 68 are arranged in parallel to one another. Then, as shown in FIG. 2, the crankshaft 61 is offset rearward with respect to the center line Lc of the cylinder 511. That is, an imaginary half straight line Lh extending toward the cylinder 511 parallel to the center line Lc of the cylinder 511 with the crankshaft center C61 of the crankshaft 61 at the end is positioned rearward of the center line Lc of the cylinder 511. From another point of view, the center line Lc of the cylinder 511 is located closer to the balancer shaft 63 than the virtual half line Lh in the offset direction Do perpendicular to the center line Lc of the cylinder 511 and the crankshaft center C61. . Thus, the crankshaft center C61 (or the imaginary half line Lh) is located on one side Do1 of the offset direction Do from the center line Lc of the cylinder 511, and the balancer shaft 63 is offset from the center line Lc of the cylinder 511 It is located on the other side Do2 of the direction Do. Here, the other side Do2 is the opposite side of the one side Do1.
 また、バランサ軸63は仮想半直線Lhに対してメイン軸67の反対側に設けられている。ここで、「バランサ軸63が仮想半直線Lhに対してメイン軸67の反対側に設けられている」とは、クランク軸心C61を通ってシリンダー511の中心線Lcに平行な仮想直線に対してバランサ軸63がメイン軸67の反対側に設けられているのと同義である。さらに、メイン軸心C67とクランク軸心C61との間の第1仮想線分L1と、仮想半直線Lhとの間には角度θ1(0°<θ1<90°)が設けられ、バランサ軸心C63とクランク軸心C61との間の第2仮想線分L2と仮想半直線Lhとの間には角度θ2(0°<θ2)とが設けられている。そして、角度θ1<角度θ2となるように、クランク軸61、バランサ軸63およびメイン軸67が配置されている。 The balancer shaft 63 is provided on the opposite side of the main shaft 67 with respect to the virtual half line Lh. Here, “the balancer shaft 63 is provided on the opposite side of the main shaft 67 with respect to the virtual half line Lh” means that the virtual straight line is parallel to the center line Lc of the cylinder 511 through the crankshaft center C61. Is equivalent to the case where the balancer shaft 63 is provided on the opposite side of the main shaft 67. Furthermore, an angle θ1 (0 ° <θ1 <90 °) is provided between the first imaginary line segment L1 between the main axial center C67 and the crankshaft center C61 and the virtual half straight line Lh. An angle θ2 (0 ° <θ2) is provided between the second imaginary line L2 and the imaginary half line Lh between C63 and the crankshaft center C61. The crankshaft 61, the balancer shaft 63, and the main shaft 67 are disposed such that the angle θ1 <the angle θ2.
 なお、線分と半直線との角度とは、これらの間にできる優角(180度より大きい角度)および劣角(180度より小さい角度)のうちの劣角を示すものとする。つまり、角度θ1および角度θ2はいずれも180度より小さい。また、ここの説明で用いた中心線Lc、仮想半直線Lh、第1仮想線分L1および第2仮想線分L2はいずれもクランク軸61の軸方向(車幅方向Dw)に垂直である。 The angle between the line segment and the half line indicates the inferior angle of the superior angle (angle greater than 180 degrees) and the inferior angle (angle smaller than 180 degrees) formed therebetween. That is, both the angle θ1 and the angle θ2 are smaller than 180 degrees. Further, the center line Lc, the virtual half line Lh, the first virtual segment L1 and the second virtual segment L2 used in the description herein are all perpendicular to the axial direction of the crankshaft 61 (the vehicle width direction Dw).
 このように構成されたエンジン5では、クランク軸心C61を端としてシリンダー511の中心線Lcに平行にシリンダー511側に延びる仮想半直線Lhの両側にメイン軸67およびバランサ軸63それぞれのマスが分散する。そのため、メイン軸67の配置はマスの集中に影響する。そこで、本実施形態では、角度θ1<角度θ2を満たすように、メイン軸67が配置されている。つまり、この角度関係を満たすように、クランク軸心C61を端とする仮想半直線Lhにメイン軸67を近づけて配置して、マスの集中を図っている。これによって、メイン軸67、クランク軸61およびバランサ軸63を備えたエンジン5において、マスの集中を図ることが可能となっている。 In the engine 5 configured in this manner, the mass of each of the main shaft 67 and the balancer shaft 63 is distributed on both sides of an imaginary half straight line Lh extending to the cylinder 511 side parallel to the center line Lc of the cylinder 511 with the crankshaft center C61 as an end. Do. Therefore, the arrangement of the main shaft 67 affects the concentration of mass. Therefore, in the present embodiment, the main shaft 67 is disposed so as to satisfy the angle θ1 <the angle θ2. That is, in order to satisfy this angular relationship, the main axis 67 is disposed close to the virtual half line Lh having the crankshaft center C61 as an end to achieve mass concentration. Thus, in the engine 5 provided with the main shaft 67, the crankshaft 61, and the balancer shaft 63, it is possible to achieve mass concentration.
 さらに、図2に示すように、貯留部55の下端部55Bはクランク軸61の下側に配置され、貯留部55の上端部55T(下端部55Bより上側の部分)は、クランク軸61のオフセット方向Doの他方側Do2に配置されている。これに伴って、貯留部55の当該上端部55T内に設けられた貯留室551の上端部551Tも、クランク軸61のオフセット方向Doの他方側Do2に位置する。また、バランサ軸63は、オフセット方向Doにおける貯留室551の上端部55Tとクランク軸61とに挟まれるように配置されている。なお、貯留部55、クランク軸61、バランサ軸63およびトランスミッション66(メイン軸67、ドライブ軸68)のレイアウトについては、図6および図7を用いて後に詳述する。 Further, as shown in FIG. 2, the lower end 55 B of the reservoir 55 is disposed below the crankshaft 61, and the upper end 55 T (portion above the lower end 55 B) of the reservoir 55 is an offset of the crankshaft 61. It is arranged on the other side Do2 of the direction Do. Along with this, the upper end 551T of the storage chamber 551 provided in the upper end 55T of the storage portion 55 is also located on the other side Do2 of the offset direction Do of the crankshaft 61. The balancer shaft 63 is disposed so as to be sandwiched between the upper end 55T of the storage chamber 551 and the crankshaft 61 in the offset direction Do. The layout of the storage portion 55, the crankshaft 61, the balancer shaft 63, and the transmission 66 (main shaft 67, drive shaft 68) will be described in detail later with reference to FIGS.
 続いて、図5を用いてエンジンオイルを循環させるオイル循環系について説明する。ここで、図5はエンジンが備えるオイル循環系の一例を示すブロック図である。図5において矢印はエンジンオイルが流れる方向示す。エンジン5は、ポンプギアの回転により駆動されるスカベンジポンプ91を備え、スカベンジポンプ91は、配管T1を介してクランク室541に接続されている。したがって、クランク室541内でオイルパン544に落下したエンジンオイルは、スカベンジポンプ91によって吸引されてクランク室541から排出される。この際、エンジンオイルは、クランク室541内のストレーナー547により濾過されてからスカベンジポンプ91に向けて排出される。 Subsequently, an oil circulation system for circulating the engine oil will be described with reference to FIG. Here, FIG. 5 is a block diagram showing an example of an oil circulation system provided in the engine. Arrows in FIG. 5 indicate the direction in which the engine oil flows. The engine 5 includes a scavenge pump 91 driven by rotation of a pump gear, and the scavenge pump 91 is connected to the crank chamber 541 via a pipe T1. Therefore, the engine oil that has dropped into the oil pan 544 in the crank chamber 541 is sucked by the scavenge pump 91 and discharged from the crank chamber 541. At this time, engine oil is filtered by a strainer 547 in the crank chamber 541 and then discharged to the scavenge pump 91.
 スカベンジポンプ91は、吸引したエンジンオイルを、貯留部55に連通する配管T2に圧送する。したがって、スカベンジポンプ91から送り出されたエンジンオイルは配管T2を介して貯留部55に戻される。こうして、スカベンジポンプ91によってクランク室541から吸引されたエンジンオイルが貯留部55に貯留される。また、貯留部55とクランク室541とは、配管T3を介して連通しており、貯留部55で溢れたエンジンオイルは、配管T3を介してクランク室541に排出される。 The scavenge pump 91 pressure-feeds the sucked engine oil to the pipe T2 communicating with the reservoir 55. Therefore, the engine oil delivered from the scavenge pump 91 is returned to the reservoir 55 via the pipe T2. Thus, the engine oil sucked from the crank chamber 541 by the scavenge pump 91 is stored in the storage portion 55. The reservoir 55 and the crank chamber 541 communicate with each other through the pipe T3, and the engine oil overflowing in the reservoir 55 is discharged to the crank chamber 541 through the pipe T3.
 エンジン5は、ポンプギアの回転により駆動されるフィードポンプ93を備え、フィードポンプ93は、配管T4を介して貯留部55に接続されている。したがって、貯留部55内に貯留されたエンジンオイルは、フィードポンプ93によって吸引されて貯留部55から排出される。この際、エンジンオイルは、貯留部55内のストレーナー552により濾過されてからフィードポンプ93に向けて排出される。フィードポンプ93は、配管T5、T6を介してリリーフバルブ94に接続されている。フィードポンプ93での圧力が所定値より大きくなるとリリーフバルブ94が作動して、フィードポンプ93から配管T5へエンジンオイルが排出され、このエンジンオイルが配管T6を介してフィードポンプ93に戻る。 The engine 5 includes a feed pump 93 driven by rotation of a pump gear, and the feed pump 93 is connected to the reservoir 55 via a pipe T4. Therefore, the engine oil stored in the storage portion 55 is sucked by the feed pump 93 and discharged from the storage portion 55. At this time, the engine oil is filtered by the strainer 552 in the reservoir 55 and then discharged to the feed pump 93. The feed pump 93 is connected to the relief valve 94 through the pipes T5 and T6. When the pressure at the feed pump 93 becomes larger than a predetermined value, the relief valve 94 operates to discharge the engine oil from the feed pump 93 to the pipe T5, and the engine oil returns to the feed pump 93 via the pipe T6.
 フィードポンプ93は、貯留部55から吸引したエンジンオイルを、配管T7を介してオイルクリーナー95に圧送する。オイルクリーナー95の出力側には、配管T8および配管T9が接続されており、オイルクリーナー95に圧送されたエンジンオイルは、オイルクリーナー95により浄化されてから配管T8、T9に流出する。 The feed pump 93 pressure-feeds the engine oil sucked from the reservoir 55 to the oil cleaner 95 through the pipe T7. The pipe T8 and the pipe T9 are connected to the output side of the oil cleaner 95, and the engine oil pressure-fed to the oil cleaner 95 is purified by the oil cleaner 95 and then flows out to the pipes T8 and T9.
 配管T8はクランク室541内のクランク軸61に連通しており、クランク軸61の右側のクランクジャーナル611およびクランクピン612のそれぞれにエンジンオイルを供給する。配管T9は、ピストン512および左側クランクジャーナル611のそれぞれにエンジンオイルを供給してから、シリンダーヘッド52に延びて、カムシャフト525、529にエンジンオイルを供給する。 The pipe T8 is in communication with the crankshaft 61 in the crank chamber 541, and supplies engine oil to the crank journal 611 and the crank pin 612 on the right side of the crankshaft 61. The pipe T9 supplies engine oil to each of the piston 512 and the left crank journal 611, and then extends to the cylinder head 52 to supply engine oil to the camshafts 525 and 529.
 さらに、配管T9は配管T10および配管T11に分岐する。配管T10は、メイン軸67、プライマリードリブンギア652およびクラッチ機構65にこの順でエンジンオイルを供給する。配管T11は、ミッションシャワー683およびドライブ軸68にこの順でエンジンオイルを供給する。ミッションシャワー683に供給されたエンジンオイルは、ミッションシャワー683からドライブ軸68へと注がれる。 Furthermore, the pipe T9 branches into the pipe T10 and the pipe T11. The pipe T10 supplies engine oil to the main shaft 67, the primary driven gear 652, and the clutch mechanism 65 in this order. The pipe T11 supplies engine oil to the mission shower 683 and the drive shaft 68 in this order. The engine oil supplied to the mission shower 683 is poured from the mission shower 683 to the drive shaft 68.
 続いて、図2とともに、図6および図7を併用して、エンジン5内における貯留部55のレイアウトについて詳述する。ここで、図6はオフセット方向の他方側から一方側を向いて見た貯留部およびクランク軸の配置を示す図であり、図7は貯留部、クランク軸およびバランサ軸の配置を示す部分断面図である。図6では、ピストン512が上死点に位置する際のクランク軸61が示されており、クランク軸61のうち貯留部55に隠れる部分が破線で示されている。図7ではバランサ軸63のウェイト631が前側Dfに最も寄った際の上面視における配置を示すとともに、バランサ軸63のウェイト631の回転軌跡631T(すなわち、ウェイト631が1回転する間に通る領域)を併せて示す。また、図7では、車幅方向Dwにおける右側Drおよび左側Dlが示されている。 Subsequently, the layout of the storage portion 55 in the engine 5 will be described in detail using FIG. 6 and FIG. 7 together with FIG. Here, FIG. 6 is a view showing the arrangement of the storage section and the crankshaft as viewed from the other side in the offset direction toward the one side, and FIG. 7 is a partial sectional view showing the arrangement of the storage section, the crankshaft and the balancer shaft It is. In FIG. 6, the crankshaft 61 when the piston 512 is located at the top dead center is shown, and a portion of the crankshaft 61 hidden by the reservoir 55 is shown by a broken line. FIG. 7 shows the arrangement in a top view when the weight 631 of the balancer shaft 63 is closest to the front side Df, and the rotation locus 631T of the weight 631 of the balancer shaft 63 (that is, the area passing through one rotation of the weight 631) Together. Further, in FIG. 7, the right side Dr and the left side Dl in the vehicle width direction Dw are shown.
 上述のとおり、貯留部55の上端部55Tと、その内部の貯留室551の上端部551Tは、クランク軸61のオフセット方向Doの他方側Do2に配置されている。その結果、図6に示すように、オフセット方向Doから見て、貯留部55の上端部55Tはクランク軸61と重なり、クランク軸61の一部が貯留部55の上端部55Tに隠れる。より詳しくは、左右のクランクジャーナル611の全体は貯留部55の上端部55Tに隠れる。また、ピストン512が上死点に位置する状態において、左右のカウンターウェイト613の全体が貯留部55の上端部55Tに隠れ、クランクピン612の全体が貯留部55の上端部55Tに隠れ、クランクアーム615の上端615aが僅かに貯留部55の上端部55Tから突出し、クランクアーム615の当該上端615a以外の部分が貯留部55の上端部55Tに隠れる。なお、ここではオフセット方向Doから見た配置関係を説明したが、前後方向Dp(水平方向)から見た場合にもここでの説明と同様の配置関係が満たされている。 As described above, the upper end 55T of the storage portion 55 and the upper end 551T of the storage chamber 551 therein are disposed on the other side Do2 of the offset direction Do of the crankshaft 61. As a result, as shown in FIG. 6, when viewed in the offset direction Do, the upper end 55T of the reservoir 55 overlaps the crankshaft 61, and a part of the crankshaft 61 is hidden by the upper end 55T of the reservoir 55. More specifically, the entire left and right crank journals 611 are hidden at the upper end 55T of the reservoir 55. When the piston 512 is at the top dead center, the entire left and right counterweights 613 are hidden by the upper end 55T of the reservoir 55, and the entire crankpin 612 is hidden by the upper end 55T of the reservoir 55. The upper end 615a of 615 slightly protrudes from the upper end 55T of the reservoir 55, and the portion of the crank arm 615 other than the upper end 615a is hidden by the upper end 55T of the reservoir 55. Although the arrangement relation viewed from the offset direction Do has been described here, the arrangement relation similar to the explanation here is satisfied also when viewed from the front-rear direction Dp (horizontal direction).
 また、図7に示すように、貯留部55の貯留室551は、第1貯留室553と第2貯留室554とに隔壁555によって区分けされており、第1貯留室553と第2貯留室554とは隔壁555を挟んで車幅方向Dwに隣接する。こうして、貯留部55内では、第1貯留室553と第2貯留室554とがバランサ軸63の軸方向、すなわち車幅方向Dwに配列されている。これら第1貯留室553および第2貯留室554のうち、左側Dlの第1貯留室553には、右側Drの第2貯留室554から後側Db(バランサ軸63側)に突出した突出部553Jが設けられている。なお、これら第1・第2貯留室553、554は、上端部551Tを含む貯留室551の全体に渡って設けられ、相互に連通している。したがって、エンジンオイルは、第1貯留室553と第2貯留室554との間を往来できる。 Further, as shown in FIG. 7, the storage chamber 551 of the storage unit 55 is divided into a first storage chamber 553 and a second storage chamber 554 by the partition wall 555, and the first storage chamber 553 and the second storage chamber 554. Are adjacent to each other in the vehicle width direction Dw with the partition wall 555 interposed therebetween. Thus, in the storage section 55, the first storage chamber 553 and the second storage chamber 554 are arranged in the axial direction of the balancer shaft 63, that is, in the vehicle width direction Dw. Of the first storage chamber 553 and the second storage chamber 554, the first storage chamber 553 on the left side Dl is a projecting portion 553J that protrudes from the second storage chamber 554 on the right side Dr to the rear side Db (balancer shaft 63 side). Is provided. The first and second storage chambers 553 and 554 are provided over the entire storage chamber 551 including the upper end portion 551T and are in communication with each other. Therefore, engine oil can pass between the first reservoir 553 and the second reservoir 554.
 これら第1・第2貯留室553、554に対して、バランサ軸63のウェイト631が次のように配置されている。つまり、ウェイト631の回転軌跡631Tは、第1貯留室553の突出部553Jの車幅方向Dwの右側Dr(すなわち、第2貯留室554側)に位置している。そして、車幅方向Dwにおいて、ウェイト631の回転軌跡631Tの両端631r、631lは、第2貯留室554の両端554r、554lの間に位置する。かかるウェイト631の回転軌跡631Tは、突出部553Jに対して車幅方向Dwに離間しつつ対向する。換言すれば、ウェイト631の前側Dfの端631fは、突出部553Jの後側Dbの端553bより前側Dfに位置し、車幅方向Dwから見て、第1貯留室551aの突出部551Jとウェイト631の回転軌跡631Tとは、部分的に互いに重複する。 The weight 631 of the balancer shaft 63 is arranged as follows with respect to the first and second storage chambers 553 and 554. That is, the rotation locus 631T of the weight 631 is located on the right side Dr (that is, the second storage chamber 554 side) in the vehicle width direction Dw of the protrusion 553J of the first storage chamber 553. Then, in the vehicle width direction Dw, both ends 631r, 6311 of the rotation locus 631T of the weight 631 are located between the both ends 554r, 554l of the second storage chamber 554. The rotation locus 631T of the weight 631 faces the projection 553J while being separated in the vehicle width direction Dw. In other words, the end 631f of the front side Df of the weight 631 is located on the front side Df from the end 553b of the rear side Db of the protrusion 553J, and the projection 551J of the first storage chamber 551a and the weight when viewed from the vehicle width direction Dw. The rotation trajectories 631T of 631 partially overlap each other.
 また、図2に示すように、貯留部55は、クランク軸心C61とバランサ軸63とを通る仮想直線I(すなわち、第2仮想線分L2を通る仮想直線)を跨ぐように設けられ、換言すれば、仮想直線Iに対してオイルパン544の側からオイルパン544の反対側にまで延設されている。このように、貯留部55の一部が仮想直線Iに対してオイルパン544の反対の方向に位置するほどに、貯留部55が延設されている。 Further, as shown in FIG. 2, the storage portion 55 is provided so as to straddle an imaginary straight line I passing through the crankshaft center C61 and the balancer shaft 63 (that is, an imaginary straight line passing through the second imaginary line segment L2). If it does, it extends from the side of the oil pan 544 to the opposite side of the oil pan 544 with respect to the imaginary straight line I. As described above, the reservoir 55 is extended such that a part of the reservoir 55 is located in the opposite direction of the oil pan 544 with respect to the imaginary straight line I.
 また、クランクケース53は、その外壁面を構成する外壁部531を有する。そして、貯留部55の壁面は、外壁部531の外壁面により構成されている。つまり、外壁部531は、クランクケース53の壁として機能するとともに、貯留部55の壁としても機能する。このように、クランクケース53の一部の壁と貯留部55の一部の壁とが共通化されている。 Further, the crankcase 53 has an outer wall portion 531 that constitutes the outer wall surface thereof. The wall surface of the storage portion 55 is constituted by the outer wall surface of the outer wall portion 531. That is, the outer wall portion 531 functions as a wall of the crankcase 53 and also functions as a wall of the storage portion 55. Thus, a part of the wall of the crankcase 53 and a part of the wall of the reservoir 55 are made common.
 以上に説明したエンジン5では、クランク軸61のクランク軸心C61をシリンダー511の中心線Lcより一方側Do1に位置させることで、シリンダー511の中心線Lcの他方側Do2にスペースを確保している。そして、貯留部55の上端部55Tを、オフセット方向Doから見てクランク軸61に重なるようにシリンダー511の中心線Lcの他方側Do2に配置して、このスペースを有効活用している。これによって、エンジンオイルの貯留容積を広く確保しつつエンジン5の大型化を抑制することが可能となっている。 In the engine 5 described above, a space is secured on the other side Do2 of the center line Lc of the cylinder 511 by positioning the crankshaft center C61 of the crankshaft 61 on one side Do1 of the center line Lc of the cylinder 511 . Then, the upper end 55T of the reservoir 55 is disposed on the other side Do2 of the center line Lc of the cylinder 511 so as to overlap the crankshaft 61 when viewed from the offset direction Do, and this space is effectively used. By this, it is possible to suppress the enlargement of the engine 5 while securing a large storage volume of engine oil.
 さらに言えば、上記のエンジン5は、ドライサンプ方式の特徴を活用することで、かかる効果を効果的に奏している。つまり、ウェットサンプでは、クランクケース53の底に設けられたオイルパン544そのものにエンジンオイルを貯留する。したがって、クランク軸61がエンジンオイルに漬かるのを避けるために、多くのエンジンオイルを貯留することができない。これに対して、上記のエンジン5は、オイルパンから貯留部55にエンジンオイルを送るドライサンプ方式を採用しているため、クランク軸61がエンジンオイルに漬かることなく、上述のようにエンジンオイルの貯留容積を広く確保することが可能となっている。 Furthermore, the above-mentioned engine 5 exerts such an effect effectively by utilizing the features of the dry sump method. That is, in the wet sump, the engine oil is stored in the oil pan 544 itself provided at the bottom of the crankcase 53. Therefore, a large amount of engine oil can not be stored in order to prevent the crankshaft 61 from getting soaked in the engine oil. On the other hand, since the above-mentioned engine 5 adopts the dry sump method of sending the engine oil from the oil pan to the storage portion 55, the crankshaft 61 is not immersed in the engine oil, and the engine oil is stored as described above. It is possible to secure a large volume.
 また、図2に示すように、クランクケース53内では、トランスミッション66は、オフセット方向Doにおいてシリンダー511の中心線Lcより一方側Do1に配置されている。つまり、トランスミッション66と貯留部55の上端部55Tとはシリンダー511の中心線Lcを挟んで互いに反対側に位置する。したがって、貯留部55の上端部55Tの容積を、トランスミッション66の配置スペースに妨げられることなく確保することが可能となっている。 Further, as shown in FIG. 2, in the crankcase 53, the transmission 66 is disposed on one side Do1 from the center line Lc of the cylinder 511 in the offset direction Do. That is, the transmission 66 and the upper end 55T of the reservoir 55 are located on opposite sides of the center line Lc of the cylinder 511. Therefore, it is possible to secure the volume of the upper end 55T of the reservoir 55 without being obstructed by the arrangement space of the transmission 66.
 また、貯留部55の上端部55Tとクランク軸61との間に、クランク軸61に連動して回転するバランサ軸63が設けられている。つまり、上記のエンジン5では、クランク軸61をシリンダー511の中心線Lcより一方側Do1に位置させることで、シリンダー511の中心線Lcの他方側Do2にスペースを確保している。したがって、シリンダー511の中心線Lcの他方側Do2にエンジンオイルの貯留容積を確保しつつ、さらにバランサ軸63を配置することができる。 Further, a balancer shaft 63 that rotates in conjunction with the crankshaft 61 is provided between the upper end 55 T of the storage portion 55 and the crankshaft 61. That is, in the engine 5 described above, the crankshaft 61 is positioned on one side Do1 of the center line Lc of the cylinder 511, thereby securing a space on the other side Do2 of the center line Lc of the cylinder 511. Therefore, the balancer shaft 63 can be further disposed while securing the engine oil storage volume on the other side Do2 of the center line Lc of the cylinder 511.
 また、貯留部55の上端部55Tは、バランサ軸63の軸方向、すなわち車幅方向Dwに配列された第1貯留室553および第2貯留室554を有し、第1貯留室553および第2貯留室554それぞれの内部にオイルを貯留する。車幅方向Dwにおいて、バランサ軸63のウェイト631は、第2貯留室554の両端554r、554lの間に位置する。また、第1貯留室553は、前後方向Dpに第2貯留室554よりもウェイト631側に突出する突出部553Jを有し、突出部553Jの一部は、車幅方向Dwから見て、バランサ軸63のウェイト631の回転軌跡631Tと重なる。かかる構成では、貯留部55の第1貯留室553に突出部553Jが設けられており、より多くのエンジンオイルを、貯留部55とバランサ軸63との干渉を防止しつつ貯留することができる。 The upper end 55T of the storage portion 55 has a first storage chamber 553 and a second storage chamber 554 arranged in the axial direction of the balancer shaft 63, that is, in the vehicle width direction Dw. The oil is stored in each of the storage chambers 554. In the vehicle width direction Dw, the weight 631 of the balancer shaft 63 is located between both ends 554r and 554l of the second storage chamber 554. In addition, the first storage chamber 553 has a projecting portion 553J that protrudes to the weight 631 side more than the second storage chamber 554 in the front-rear direction Dp, and a part of the projecting portion 553J is a balancer as viewed from the vehicle width direction Dw. It overlaps with the rotation locus 631T of the weight 631 of the shaft 63. In this configuration, the protrusion 553J is provided in the first storage chamber 553 of the storage 55, and more engine oil can be stored while preventing interference between the storage 55 and the balancer shaft 63.
 また、貯留部55は、クランク軸心C61とバランサ軸63とを通る仮想直線Iに対してオイルパン544の側からオイルパン544の反対側にまで延設されている。これによって、エンジンオイルの貯留容積が広く確保されている。 The storage portion 55 is extended from the side of the oil pan 544 to the opposite side of the oil pan 544 with respect to an imaginary straight line I passing through the crankshaft center C 61 and the balancer shaft 63. As a result, a large storage volume of engine oil is secured.
 また、クランクケース53は、外壁面を構成する外壁部531を有し、貯留部55の壁面の少なくとも一部は、外壁部531の外壁面により構成されている。これによって、クランクケース53内の容積を有効に活用して、エンジンオイルの貯留容積が広く確保されている。 Further, the crankcase 53 has an outer wall portion 531 constituting an outer wall surface, and at least a part of the wall surface of the storage portion 55 is constituted by the outer wall surface of the outer wall portion 531. As a result, the volume in the crankcase 53 is effectively utilized to ensure a wide storage volume of engine oil.
 このように上記実施形態では、エンジン5が本発明の「エンジン」の一例に相当する。シリンダー511が本発明の「シリンダー」の一例に相当する。クランクケース53が本発明の「クランクケース」の一例に相当する。外壁部531が本発明の「外壁部」の一例に相当する。クランク軸61が本発明の「クランク軸」の一例に相当する。クランク軸心C61が本発明の「クランク軸心」の一例に相当する。ピストン512が本発明の「ピストン」の一例に相当する。コネクティングロッド62が本発明の「コネクティングロッド」の一例に相当する。オイルパン544が本発明の「オイルパン」の一例に相当する。貯留部55が本発明の「貯留部」の一例に相当する。第1貯留室553が本発明の「第1貯留室」の一例に相当する。第2貯留室554が本発明の「第2貯留室」の一例に相当する。突出部553Jが本発明の「突出部」の一例に相当する。スカベンジポンプ91が本発明の「スカベンジポンプ」の一例に相当する。オフセット方向Doが本発明の「オフセット方向」の一例に相当する。一方側Do1が本発明の「一方側」の一例に相当する。他方側Do2が本発明の「他方側」の一例に相当する。バランサ軸63が本発明の「バランサ軸」の一例に相当する。ウェイト631が本発明の「ウェイト」の一例に相当する。回転軌跡631Tが本発明の「回転軌跡」の一例に相当する。トランスミッション66が本発明の「トランスミッション」の一例に相当する。自動二輪車1が本発明の「車両」の一例に相当する。前輪34および後輪37が本発明の「車輪」の一例に相当する。 Thus, in the said embodiment, the engine 5 is corresponded to an example of the "engine" of this invention. The cylinder 511 corresponds to an example of the "cylinder" of the present invention. The crankcase 53 corresponds to an example of the "crankcase" in the present invention. The outer wall 531 corresponds to an example of the “outer wall” in the present invention. The crankshaft 61 corresponds to an example of the "crankshaft" of the present invention. The crankshaft center C61 corresponds to an example of the "crankshaft center" in the present invention. The piston 512 corresponds to an example of the "piston" of the present invention. The connecting rod 62 corresponds to an example of the "connecting rod" of the present invention. The oil pan 544 corresponds to an example of the "oil pan" of the present invention. Storage part 55 is equivalent to an example of a "storage part" of the present invention. The first storage chamber 553 corresponds to an example of the “first storage chamber” in the present invention. The second storage chamber 554 corresponds to an example of the “second storage chamber” in the present invention. The projecting portion 553J corresponds to an example of the "projecting portion" in the present invention. The scavenge pump 91 corresponds to an example of the “scavenge pump” of the present invention. The offset direction Do corresponds to an example of the “offset direction” in the present invention. One side Do1 corresponds to an example of "one side" of the present invention. The other side Do2 corresponds to an example of the "other side" of the present invention. The balancer shaft 63 corresponds to an example of the “balancer shaft” in the present invention. The weight 631 corresponds to an example of the “weight” in the present invention. The rotation trajectory 631T corresponds to an example of the “rotation trajectory” in the present invention. The transmission 66 corresponds to an example of the "transmission" of the present invention. The motorcycle 1 corresponds to an example of the "vehicle" in the present invention. The front wheel 34 and the rear wheel 37 correspond to an example of the "wheel" of the present invention.
 なお、本発明は上記した実施形態に限定されるものではなく、その趣旨を逸脱しない限りにおいて上述したもの以外に種々の変更を行うことが可能である。例えば、貯留部55の構成を適宜変更しても良い。具体的には、第1貯留室553と第2貯留室554との間に隔壁555を設ける必要は必ずしも無く、突出部553Jを設ける必要も必ずしも無い。 The present invention is not limited to the above-described embodiment, and various modifications can be made other than the above without departing from the scope of the invention. For example, the configuration of the storage unit 55 may be changed as appropriate. Specifically, it is not necessary to provide the partition 555 between the first storage chamber 553 and the second storage chamber 554, and it is not always necessary to provide the projection 553J.
 また、貯留部55あるいは貯留室551と、クランク軸61を重複させる程度を適宜変更しても良く、貯留部55の上端部55Tとクランク軸61との間にバランサ軸63を配置する必要も必ずしも無い。 Further, the degree of overlapping the storage portion 55 or the storage chamber 551 with the crankshaft 61 may be changed as appropriate, and the balancer shaft 63 needs to be disposed between the upper end portion 55T of the storage portion 55 and the crankshaft 61 There is not.
 また、上記では、単一のシリンダー511をシリンダーブロック51に備えた単気筒型のエンジン5を例示した。しかしながら、エンジン5が備えるシリンダー511の個数は1個に限られず、2個以上であってもよい。 Also, in the above, the single-cylinder engine 5 having the single cylinder 511 in the cylinder block 51 is illustrated. However, the number of cylinders 511 provided in the engine 5 is not limited to one, and may be two or more.
 また、エンジン5が備える吸排気バルブ機構は、上述のDOHCに限られず、SOHC(Single Over Head Camshaft)等の他の機構であっても構わない。さらに、吸気バルブ523や排気バルブ527の駆動方式は上記の直動式に限られず、ロッカーアーム式等の他の方式でも構わない。 In addition, the intake and exhaust valve mechanism provided in the engine 5 is not limited to the above-described DOHC, and may be another mechanism such as SOHC (Single Over Head Camshaft). Furthermore, the drive system of the intake valve 523 and the exhaust valve 527 is not limited to the above-described direct acting system, and other systems such as a rocker arm system may be used.
 また、シリンダー511の姿勢は、上述の後傾に限られず、前傾あるいは直立でも構わない。 Further, the posture of the cylinder 511 is not limited to the above-described backward inclination, and may be forward inclination or upright.
 また、クランクケース53の具体的な構成は適宜変更してもよい。したがって、例えば貯留部55を一体的に備える必要は必ずしも無い。 Also, the specific configuration of the crankcase 53 may be changed as appropriate. Therefore, for example, it is not necessary to integrally provide the storage unit 55.
 また、エンジン5を車体フレーム2に取り付ける位置あるいは角度は、上の例に限られず、適宜変更することができる。 Further, the position or angle at which the engine 5 is attached to the vehicle body frame 2 is not limited to the above example, and can be changed as appropriate.
 この発明は、エンジンオイルを用いるエンジンおよび当該エンジンを備えた車両の全般に適用することができる。 The present invention can be applied to all engines using engine oil and vehicles equipped with such engines.
 1…自動二輪車(車両)
 34…前輪(車輪)
 37…後輪(車輪)
 5…エンジン
 511…シリンダー
 512…ピストン
 53…クランクケース
 531…外壁部
 544…オイルパン
 55…貯留部
 553…第1貯留室
 553J…突出部
 554…第2貯留室
 61…クランク軸
 62…コネクティングロッド
 63…バランサ軸
 631…ウェイト
 631T…回転軌跡
 91…CRスカベンジポンプ
 C61…クランク軸心
 Do…オフセット方向
 Do1…一方側
 Do2…他方側
1 ... Motorcycle (vehicle)
34 ... front wheel (wheel)
37 ... rear wheel (wheel)
DESCRIPTION OF SYMBOLS 5 ... Engine 511 ... Cylinder 512 ... Piston 53 ... Crankcase 531 ... Outer wall part 544 ... Oil pan 55 ... Storage part 553 ... 1st storage chamber 553 J ... Projection part 554 ... 2nd storage chamber 61 ... Crank shaft 62 ... Connecting rod 63 ... Balancer shaft 631 ... Weight 631 T ... Rotation locus 91 ... CR Scavenge pump C 61 ... Crankshaft center Do ... Offset direction Do1 ... One side Do2 ... The other side

Claims (7)

  1.  シリンダーと、
     前記シリンダーに接続されたクランクケースと、
     少なくともその一部が前記クランクケース内に配置され、前記シリンダー内を往復移動するピストンにコネクティングロッドを介して接続され、前記ピストンの往復運動に連動してクランク軸心を中心に回転するクランク軸と、
     前記クランクケース内に設けられたオイルパンと、
     前記クランクケース内に設けられ、オイルを貯留する貯留部と、
     前記オイルパンから前記貯留部にオイルを送るスカベンジポンプと
    を備え、
     前記シリンダーの中心線および前記クランク軸心のそれぞれに直交するオフセット方向において、前記クランク軸心は前記シリンダーの中心線より一方側に位置し、
     前記貯留部の少なくとも一部は、前記オフセット方向において前記シリンダーの中心線の他方側に位置し、前記オフセット方向から見て前記クランク軸と重なるエンジン。
    With the cylinder,
    A crankcase connected to the cylinder,
    At least a portion of which is disposed in the crankcase, connected to a piston reciprocating in the cylinder via a connecting rod, and connected to a crankshaft that rotates around a crankshaft center in conjunction with the reciprocating motion of the piston ,
    An oil pan provided in the crankcase;
    A reservoir provided in the crankcase for storing oil;
    And a scavenge pump for feeding oil from the oil pan to the reservoir.
    The crankshaft center is positioned on one side of the cylinder centerline in offset directions orthogonal to the cylinder centerline and the crankshaft center, respectively.
    At least a portion of the storage portion is located on the other side of the center line of the cylinder in the offset direction, and overlaps the crankshaft when viewed from the offset direction.
  2.  前記クランクケース内に配置されるトランスミッションをさらに備え、
     前記トランスミッションは、前記オフセット方向において前記シリンダーの中心線より前記一方側に位置する請求項1に記載のエンジン。
    Further comprising a transmission disposed within the crankcase,
    The engine according to claim 1, wherein the transmission is located on the one side of a center line of the cylinder in the offset direction.
  3.  前記貯留部の少なくとも一部と前記クランク軸との間に、前記クランク軸に連動して回転するバランサ軸をさらに備える請求項1または2に記載のエンジン。 The engine according to claim 1, further comprising a balancer shaft that rotates in conjunction with the crankshaft, between at least a portion of the storage portion and the crankshaft.
  4.  前記貯留部の少なくとも一部は、前記バランサ軸の軸方向に配列された第1貯留室および第2貯留室を有し、前記第1貯留室および前記第2貯留室それぞれの内部にオイルを貯留し、
     前記バランサ軸の軸方向において、前記バランサ軸のウェイトは、前記第2貯留室の両端の間に位置し、
     前記第1貯留室は、前記バランサ軸の軸方向に垂直な垂直方向に前記第2貯留室よりも前記バランサ軸側に突出する突出部を有し、
     前記突出部の少なくとも一部は、前記バランサ軸の軸方向から見て、前記バランサ軸のウェイトの回転軌跡と重なる請求項3に記載のエンジン。
    At least a part of the storage unit has a first storage chamber and a second storage chamber arranged in the axial direction of the balancer shaft, and oil is stored in the first storage chamber and the second storage chamber, respectively. And
    The weight of the balancer shaft is located between both ends of the second storage chamber in the axial direction of the balancer shaft,
    The first storage chamber has a projecting portion which protrudes in the vertical direction perpendicular to the axial direction of the balancer shaft in a direction perpendicular to the balancer shaft with respect to the second storage chamber.
    4. The engine according to claim 3, wherein at least a part of the protrusion overlaps with a rotation trajectory of the weight of the balancer shaft when viewed from the axial direction of the balancer shaft.
  5.  前記貯留部の少なくとも一部は、前記バランサ軸の軸方向から見て、前記クランク軸心と前記バランサ軸の回転中心とを通る直線に対して前記オイルパンとは反対の方向に位置する請求項3または4に記載のエンジン。 At least a part of the storage portion is located in a direction opposite to the oil pan with respect to a straight line passing through the crankshaft center and the rotation center of the balancer shaft when viewed from the axial direction of the balancer shaft. The engine according to 3 or 4.
  6.  前記クランクケースは、外壁面を構成する外壁部を有し、
     前記貯留部の壁面の少なくとも一部は、前記外壁部の前記外壁面により構成される請求項1ないし5のいずれか一項に記載のエンジン。
    The crankcase has an outer wall portion forming an outer wall surface,
    The engine according to any one of claims 1 to 5, wherein at least a part of the wall surface of the storage portion is configured by the outer wall surface of the outer wall portion.
  7.  請求項1ないし6のいずれか一項に記載のエンジンと、
     前記エンジンにより駆動される車輪と
    を備える車両。
    An engine according to any one of claims 1 to 6;
    A vehicle comprising: a wheel driven by the engine.
PCT/JP2018/028981 2017-08-03 2018-08-02 Engine and vehicle WO2019026989A1 (en)

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JP2004108257A (en) * 2002-09-18 2004-04-08 Honda Motor Co Ltd Lubrication device of internal combustion engine
JP2008045529A (en) * 2006-08-21 2008-02-28 Honda Motor Co Ltd Lubrication device of internal combustion engine
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JPS5330052B2 (en) 1971-11-29 1978-08-24
JP2004108257A (en) * 2002-09-18 2004-04-08 Honda Motor Co Ltd Lubrication device of internal combustion engine
JP4451234B2 (en) * 2004-07-08 2010-04-14 ヤマハ発動機株式会社 engine
JP2008045529A (en) * 2006-08-21 2008-02-28 Honda Motor Co Ltd Lubrication device of internal combustion engine
JP2014227970A (en) * 2013-05-24 2014-12-08 スズキ株式会社 Engine for motorcycle
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