WO2019026989A1

WO2019026989A1 - Engine and vehicle

Info

Publication number: WO2019026989A1
Application number: PCT/JP2018/028981
Authority: WO
Inventors: 真浩和久田
Original assignee: ヤマハ発動機株式会社
Priority date: 2017-08-03
Filing date: 2018-08-02
Publication date: 2019-02-07
Also published as: EP3663547B1; EP3663547A1; EP3663547A4

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

Engine, vehicle

The present invention relates to a technology for storing oil supplied to each part of an engine.

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.

Patent No. 5330052

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

In the present invention, it is possible to suppress the size increase of the engine while securing a large oil storage volume.

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. The fragmentary sectional view which shows the internal structure of an engine by the cross section outside FIG. FIG. 4 is a partial cross-sectional view of the engine along the IV-IV cut line shown in FIG. 3; The block diagram showing an example of the oil circulation system with which an engine is provided. 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. 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.

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.

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. 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.

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.

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.

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. 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.

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.

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.

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.

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.

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.

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, 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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Further, the posture of the cylinder 511 is not limited to the above-described backward inclination, and may be forward inclination or upright.

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.

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.

The present invention can be applied to all engines using engine oil and vehicles equipped with such engines.

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

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.
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.
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.
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.
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.
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.
An engine according to any one of claims 1 to 6;
A vehicle comprising: a wheel driven by the engine.