JP3569539B2 - Motorcycle - Google Patents

Description

[0001]
[Industrial applications]
According to the present invention, an article storage chamber is provided below a seat, a two-cycle engine is disposed below the seat with its cylinder axis substantially horizontal, and the engine and a transmission for transmitting power of the engine to a rear wheel. The present invention relates to a motorcycle in which a power unit including a mechanism is swingably supported on a body frame.
[0002]
[Prior art]
Conventionally, such a motorcycle is already known, for example, from Japanese Patent Application Laid-Open No. 4-59454.
[0003]
[Problems to be solved by the invention]
In the above prior art, a support shaft for supporting the power unit to the vehicle body frame is disposed at a lower front position of the engine, and an intake system such as a carburetor is disposed at an upper position of the engine. However, the distance between the support shaft and the ground contact point of the rear wheel is relatively short, so that the swing angle of the power unit becomes relatively large, and the handling of the exhaust system of the engine is restricted. Therefore, it is simply conceivable to support the power unit on the body frame above the engine, but in that case, it is necessary to avoid a reduction in the degree of freedom in the arrangement of the intake system, and if the overall height of the engine increases, The volume of the article storage room must also be reduced.
[0004]
The present invention has been made in view of such circumstances, and has a relatively large degree of freedom in the arrangement of the intake system, a relatively low overall height of the engine, and a relatively low swing angle of the power unit. An object of the present invention is to provide a motorcycle that can be kept small.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is characterized in that a two-stroke engine in which an article storage chamber is provided below a seat and an axis of a crankshaft is arranged in a lateral direction of a vehicle body with its cylinder axis substantially horizontal. A rear wheel is disposed behind the engine and a rear wheel is disposed behind the engine, and a power unit including the engine and a transmission mechanism for transmitting the power of the engine to the rear wheel is swingable to a vehicle body frame. In a supported motorcycle, an intake port which is located near the cylinder axis in plan view and is opened on the upper surface of the crankcase is provided on the upper part of the crankcase of the engine, and the axis of the port and the cylinder axis are connected to the crankshaft. Are provided at an obtuse angle in a plane perpendicular to the axis of the cylinder. At the top of this power unit, an air cleaner extending rearward from the rear end of the unit, and a carburetor connected to the air outlet of the air cleaner and inclined inward in the front of the vehicle are mounted on the power unit. Disposed between the carburetor and the intake port,In plan viewConnected by an intake pipe with an obtuse bend, A wind guide duct that guides the air that has cooled the engine to the carburetor, and a cover that is connected to the air cleaner and covers the outside of the carburetor are integrally connected.It is characterized by the following.
[0006]
According to a second aspect of the present invention, in addition to the above-described feature of the first aspect, the intake pipe is provided at an upper portion of a crankcase, and is operatively connected to a crankshaft. According to a third aspect of the present invention, in addition to the second aspect, the accessory is accommodated in a recess provided on an upper surface of a crankcase at a position below the intake pipe. It is characterized by.
[0007]
According to a fourth aspect of the present invention, in addition to the above features of the first, second or third aspect, the filter material accommodated in the air cleaner is arranged on the vehicle body rear side with respect to the rear end of the article storage chamber. Features.
[0008]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0009]
1 to 14 show an embodiment of the present invention. FIG. 1 is a side view of a scooter type motorcycle, FIG. 2 is a plan view of FIG. 1 as viewed in the direction of arrow 2, and FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 3, FIG. 5 is a longitudinal sectional view partially cut away along line 5-5 of FIG. 4, and FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 7, FIG. 7 is a sectional view taken along line 7-7 of FIG. 4, FIG. 8 is a sectional view taken along line 8-8 of FIG. 7, FIG. 9 is a sectional view taken along line 9-9 of FIG. 11 is a sectional view taken along line 11-11 of FIG. 7, FIG. 12 is an enlarged sectional view taken along line 12-12 of FIG. 3, FIG. 13 is an enlarged sectional view taken along line 13-13 of FIG. 4, and FIG. It is sectional drawing which expands and shows the input shaft of a pump.
[0010]
First, in FIGS. 1 and 2, a body frame F of a scooter type motorcycle V has a head pipe 1 which supports a front fork 7 on which a front wheel Wf is suspended so as to be steerable, and a down tube which extends downward from the head pipe 1. 2, and a rear frame 3 and the like, which are connected to the lower end of the down tube 2 and extend rearward. The rear frame 3 has a pair of front frame portions 3a, 3a whose front ends are connected to the lower end of the down tube 2 and extends substantially horizontally toward the rear side, and from the rear ends of both front frame portions 3a, 3a. A pair of intermediate frame portions 3b, 3b extending upward and rearward, and a rear frame portion 3c interconnecting the rear ends of both intermediate frame portions 3b, 3b, and are formed in a substantially elliptical shape in plan view. It is.
[0011]
The vehicle body frame F is covered by a vehicle body cover C. The vehicle body cover C is a front cover 11 that covers a front portion of the head pipe 1 and an upper portion of the front wheel Wf. A pair of left and right front side covers 13 and 13 joined to the leg shield 12 covering the front, the front cover 11 and the leg shield 12 to cover both sides of the front vehicle body, and joined to the leg shield 12 to support the feet of the driver. Left and right rear lower covers 16, 16 joined to the floor board 14, both front side covers 13, 13 and the floor board 14 to cover both side surfaces of the rear body, and both rear lower covers 16, 16 and the floor board 14 is provided with a rear upper cover 17 and the like, and a rear portion of the rear upper cover 17 Rear fender 18 covering the upper portion of the wheel Wr is attached. The upper surface of the rear upper cover 17 is open, and the upper surface opening is covered with a seat 20 on which a driver sits. Thus, the seat 20 is hinged to the upper end of the rear upper cover 17 so as to be freely opened and closed, and the luggage box 21 having the upper end opened is housed and arranged in the upper portion of the rear upper cover 17. An article storage room 22 capable of storing a helmet or the like is formed below the seat 20, and the article storage room 22 is opened and closed by the seat 20.
[0012]
Referring also to FIG. 3, the rear wheel Wr is rotatably supported by a rear portion of a power unit P that is swingably supported on a vehicle body frame F. The power unit P includes a two-cycle forced air-cooled engine E And a continuously variable transmission M as a transmission mechanism for transmitting the output of the engine E to the rear wheel Wr. Thus, the front portion of the power unit P swings to both intermediate frame portions 3b, 3b of the rear frame 3 in the body frame F via a link mechanism 24 having a support shaft 23 parallel to the rotation axis of the rear wheel Wr. A rear cushion 25 is interposed between the rear portion of the power unit P and the rear frame 3 as possible.
[0013]
4 and 5, the cylinder head 26 of the two-cycle forced air-cooled engine E is disposed between the intermediate frames 3b, 3b of the rear frame 3, and has a substantially horizontal axis. Thus, a front end of the cylinder block 27 is connected, and a crankcase 28 is connected to a rear end of the cylinder block 27. A piston 30 is slidably fitted in a cylinder bore 29 of the cylinder block 27, and the piston 30 is connected to a crankshaft 32 via a connecting rod 31.
[0014]
A cooling fan 34 is connected to one end of the crankshaft 32 protruding from the crankcase 28 via a generator 33. A shroud 36 that forms a scroll passage 35 around the cooling fan 34 includes a cooling fan 34, The cylinder head 26 and the cylinder block 27 are covered.
[0015]
Referring also to FIG. 6, the shroud 36 includes a first member 37 as a head corresponding member that covers at least the cylinder head 26 (in this embodiment, the cylinder head 26 and the cylinder block 27) from the front side, and a remaining portion. The second member 38 to be covered is joined. The first member 37 has a plurality of fins 39 provided on the cylinder head 26 and a plurality of fins 39... With the rubber 40 interposed therebetween. It is fastened to the cylinder head 26 by mounting bolts 41. That is, the cylinder head 26 has a plurality of mounting bosses 42, each of which has a tip abutting on the inner surface of the rubber 40, protruding in parallel with the axis of the cylinder block 27, and abuts on the rubber 40 and the outer surface of the rubber 40. The first member 37 has insertion holes 43 corresponding to the mounting bosses 42. The mounting bolts 41 are inserted into the insertion holes 43 with one end abutting the mounting boss 42 and the other end is engaged with the outer surface of the first member 37 through the cylindrical mounting rubber 44. Each of the mounting bosses 42 is screwed.
[0016]
The first member 37 is provided with a hole 46 for inserting a spark plug 45 screwed into the cylinder head 26. The hole 46 has an outer periphery of a plug seal 47 that is in close contact with the outer periphery of the ignition plug 45. Are engaged. A cap 48 for covering the outer end of the spark plug 45 is detachably and resiliently engaged with the plug seal 47.
[0017]
As shown in FIGS. 1 and 3, a maintenance lid 49 is attached to the floor board 14 of the vehicle body cover C so as to be openable and closable on a front extension line of the cylinder head 26. A fuel tank 50 is fixedly disposed below the floor board 14 so that refueling can be performed when the fuel tank is opened.
[0018]
The first member 37 and the second member 38 are engaged with each other so as to be able to engage and disengage in accordance with the operation of moving the first member 37 along the axis of the cylinder block 27.
[0019]
7, the second member 38 of the shroud 36 has an annular partition wall 52 projecting inward, that is, toward the cooling fan 34 substantially corresponding to the rotation locus 51 of the outermost edge of the cooling fan 34. The scroll passage 35 is formed between the partition wall 52 and the outer peripheral wall of the second member 38. The scroll passage 35 gradually increases the flow area along the rotation direction 53 of the cooling fan 34, and the outer peripheral wall of the second member 38 at the portion corresponding to the partition wall 52 Is formed so as to be gradually separated from the partition wall 52 as it proceeds downstream along. In addition, a portion of the second member 38 corresponding to the scroll passage 35 is provided with a swelling portion 38 a swelling outward in the axial direction of the cooling fan 34, and the swelling portion 38 a extends along the rotation direction 53. It is formed so that the amount of swelling gradually increases toward the downstream side. That is, the first position P on the upstream side along the rotation direction 53 in the scroll passage 35.₁As shown in FIG.₁, The first position P₁Second position P downstream of_TwoThen, as shown in FIG.₁Larger bulging amount L than_TwoIs formed at the second position P_TwoThird position P downstream of_ThreeThen, as shown in FIG._TwoLarger bulging amount L than_ThreeIs formed at the third position P_Three4th position P further downstream than_FourThen, as shown in FIG._ThreeLarger bulging amount L than_FourAs a result, a bulging portion 38a is formed.
[0020]
A circular hole 55 facing the cooling fan 34 is provided in the second member 38 so as to be coaxial with the crankshaft 32, and a plurality of suction ports 56 communicating with the circular hole 55 are provided between the partition portions 57. The cover 58 is attached to the second member 38, and a space between the second member 38 and the cover 58 is filled with a sound absorbing material 59. A large number of holes 60 are formed in a portion of the second member 38 corresponding to the sound absorbing material 59, and noise generated in the shroud 38 is absorbed by the sound absorbing material 59 through the holes 60. Is done.
[0021]
Referring again to FIG. 4, the crankcase 28 is integrally provided with a case 61 extending to one side of the rear wheel Wr. The case 61 is connected to the case 61 via a gasket 62. Constitutes the transmission case 64. Thus, a continuously variable transmission M is provided between the other end of the crankshaft 32 protruding from the crankcase 28 and the axle 65 of the rear wheel Wr rotatably supported at the rear of the transmission case 64.
[0022]
Since the continuously variable transmission M is conventionally known, its configuration will be briefly described. The crankshaft 32 includes a fixed pulley half 66 fixed to an end of the crankshaft 32, a crankshaft A drive-side transmission pulley 68 comprising a movable pulley half 67 mounted to the shaft 32 so as to be slidable in the axial direction is provided. A V-shaped annular groove 69 is formed between the fixed and movable pulley halves 66 and 67, and an endless V-belt 70 is inserted into the annular groove 69. On the back of the movable pulley half 67, a ramp plate 71 is fixed to the crankshaft 32, and between the ramp plate 71 and the movable pulley half 67, a plurality of weight rollers 72 are accommodated in a floating state. . When the rotation speed increases during rotation of the crankshaft 32, the weight roller 72 receiving the centrifugal force moves radially outward, and moves the movable pulley half 67 in a direction to approach the fixed pulley half 66, Thereby, the contact radius of the V-belt 71 to both pulley halves 66 and 67 can be increased.
[0023]
On the other hand, a driven shaft 73 parallel to the crankshaft 32 is rotatably supported by the transmission case 64, and the driven shaft 73 is connected to an axle 65 of the rear wheel Wr via a reduction gear train 74.
[0024]
The driven shaft 73 is connected to a driven transmission pulley 76 coaxial with the driven shaft 73 via a conventionally known centrifugal clutch 75. The driven transmission pulley 76 forms a pair with the drive transmission pulley 68, and the V-belt 70 is wound around the drive transmission pulley 68.
[0025]
Referring also to FIG. 12, a carburetor 80 and an air cleaner 81 connected to the carburetor 80 are disposed above the transmission case 64. The air cleaner 81 has a filter member 84 sandwiched between a first case member 82 and a second case member 83 coupled to the second case member 82, and includes a first case member 82 and a filter member 84. An unpurified chamber 85 is formed therebetween, and a purifying chamber 86 is formed between the second case member 84 and the filter material 84. The first case member 82 is connected to a suction pipe 87 that opens downward through the unpurified chamber 85, and the second case member 83 is integrally provided with a connection pipe 88 that is connected to the vaporizer 80.
[0026]
A cover 89 covering the outside of the carburetor 80 extends forward and integrally with the first case member 82 of the air cleaner 81, and the cover 89 is used for adjusting the carburetor 80. Holes 90 are provided corresponding to the vaporizers 80.
[0027]
On the other hand, in the first member 37 of the shroud 36, at a position opposite to the suction port 56 with respect to the cylinder block 27, a discharge port ( (Not shown), and an exhaust port 90 for guiding exhaust air for keeping heat to the vaporizer 80. A rubber connecting pipe 91 is connected to the exhaust port 90, and the connecting pipe 91 is further connected to the exhaust pipe 90. Is connected to one end of the air guide duct 92.
[0028]
The air guide duct 92 is formed by joining a pair of duct halves 93 and 94 to each other. The air guide duct 92 is accommodated in a concave portion 95 provided in the case member 63 of the transmission case 64 and provided on the outer surface of the case member 63. It extends to the vaporizer 80 side so as to be substantially flush. Moreover, the other end of the air guide duct 92 is fastened to the cover 89 by a screw member 96. At the other end of the air guide duct 92, a cover 93 a that covers the upper front side of the vaporizer 80 is provided integrally with the duct half 93. Moreover, the air guide duct 92 is also provided with an engaging portion (not shown) for engaging pipings related to the vaporizer 80.
[0029]
As shown in FIG. 5, an intake port 98 in which a reed valve 97 is disposed is provided at an upper portion of the crankcase 28, and the carburetor 80 is connected to the intake port 98 via an intake pipe 99. Moreover, the angle α between the axis of the cylinder block 27 and the intake port 98 is set to an obtuse angle in a plane orthogonal to the axis of the crankshaft 32, and the support shaft 23 of the link mechanism 24 for supporting the power unit P to the vehicle body frame F. Is disposed at a position between the cylinder block 27 and the intake port 98.
[0030]
In FIG. 13, a recess 101 is provided on the upper surface of the crankcase 28 at a position below the intake pipe 99, and an input shaft 104 provided with a screw gear 103 meshed with a screw gear 102 provided on the crankshaft 32. Is attached to the crankcase 28 such that most of the oil pump 105 is accommodated in the recess 101.
[0031]
As shown in FIG. 13, the screw gear 103 of the input shaft 104 meshes with the screw gear 102 of the crankshaft 32 above the crankshaft 32 in the crankcase 28. No lubrication by the lubricating oil in the transmission case 64 can be expected at the meshing portion 103. Therefore, as shown in FIG. 14, at least one of the meshing portions, for example, substantially the entire surface of the input shaft 104 having the screw gear 103, is coated with a material having a self-lubricating property, for example, a material containing a fluorine resin or the like. 106 is formed.
[0032]
Here, the plating condition and heat treatment when the input shaft 104 is made of SCM415H (JIS) and is carburized to have a carburization depth of 0.2 to 0.4 mm and a surface hardness of HRA 78 to 83. The conditions are, for example, as follows.
[0033]
[Plating treatment]
Plating film thickness: 20 ± 4μm
Plating film composition
Ni: 88.2 to 89.3 wt%
P: 9.8 to 9.9 wt%
Polytetrafluoroethylene resin: 0.8 to 2.0 wt% (3.0 to 7.0 vol%)
Particle size of tetrafluoroethylene resin: 1 μm or less
Plating film density: 7Z3-7.6 g / cm^Three
〔Heat treatment〕
Processing temperature: 300 ± 10 ° C
Processing time: 60 minutes or more
Next, the operation of this embodiment will be described. When the engine E is operated, the cooling fan 34 connected to the crankshaft 32 rotates and the air sucked from the suction port 56 flows through the scroll passage 35 from the cooling fan 34. After that, it is discharged to the cylinder head 26 and the cylinder block 27 side. Here, the scroll passage 35 gradually increases its flow area along the rotation direction 53 of the cooling fan 34. Thus, the outer peripheral portion of the second member 38 in the shroud 36 gradually expands outward in the radial direction of the cooling fan 34 as it proceeds downstream along the rotation direction 53, and corresponds to the scroll passage 35 of the second member 38. By providing a swelling portion 38 a swelling outward in the axial direction of the cooling fan 34 in the portion, the flow area of the scroll passage 35 along the rotation direction 53 is increased. Therefore, it is possible to ideally change the flow area of the scroll passage 35 along the rotation direction 53 and to minimize the outward expansion of the second member 38 along the radial direction of the cooling fan 34. This makes it possible to maintain the maintainability of the rear wheel Wr even if the distance between the cooling fan 34 and the rear wheel Wr is relatively small, thereby contributing to downsizing of the motorcycle V.
[0034]
The temperature of the air from the scroll passage 35 rises by cooling the cylinder head 26 and the cylinder block 27, and a part of the air is discharged to the outside, and the remaining heated air is guided from the exhaust port 90 through the connection pipe 91. The air is discharged toward the vaporizer 80 by the wind duct 92. Thereby, the vaporizer 80 is kept warm. Further, a cover 89 covering the outside of the carburetor 80 is integrally connected to the air cleaner 81, and the air guide duct 92 is connected to the cover 89, so that external environmental factors such as rainfall, droplets, and traveling wind are generated. Can be performed in cooperation with the air guide duct 92 and the cover 89 of the air cleaner 81, and the durability of the vaporizer 80 against the external environmental factors can be improved.
[0035]
Further, since the exhaust air from the exhaust port 90 is guided to the carburetor 80 by the air guide duct 92, there is no need to dispose the carburetor 80 in the vicinity of the shroud 36, and the restriction on disposing the carburetor 80 is eliminated. Becomes possible.
[0036]
Since such a wind guide duct 92 is accommodated in the concave portion 95 of the case member 63 in the transmission case 64 and is arranged to be substantially flush with the outer surface of the case member 63, , The air cleaner 81, the air guide duct 92, and the transmission case 64 can be arranged so as to obtain a sense of unity in appearance.
[0037]
The shroud 36 is formed by joining a first member 37 that covers the cylinder head 26 and the cylinder block 27 from the front side, and a second member 38 that covers the remaining portion. The first member 37 includes a plurality of mounting members. It is fastened to the cylinder head 26 by bolts 41. Therefore, the distance between the cylinder head 26 and the shroud 36 can be strictly set, and the shroud 36 is formed so that the flow resistance is larger than the flow resistance when the cooling air flows between the fins 39 of the cylinder head 26. In addition, it is easy to narrow the interval between the cylinder heads 26, which can contribute to improvement of the cooling efficiency by the cooling air. In particular, when the rubber 40 is sandwiched between the shroud 36 and the fins 39 as in this embodiment, it is possible to ensure that the cooling air flows between the fins 39. The efficiency can be reliably improved. Further, the rubber 40 also exerts an action of suppressing the fin noise of the cylinder head 26. Since the shroud 36 is mounted on the cylinder head 26 by the mounting bolts 41 through the mounting rubber 44, noise due to vibration can be reduced. It becomes possible.
[0038]
Moreover, the first member 37 that covers the cylinder head 26 and the cylinder block 27 from the front side is fastened to the cylinder head 26 by mounting bolts 41 whose fastening direction is along the axis of the cylinder block 27, so that the cylinder block 27 It is easy to perform the maintenance work of the engine E by removing the first member 37 of the shroud 36 with the maintenance lid 49 on the extension of the axis line being opened.
[0039]
By the way, the intake port 98 of the engine E is provided at the upper part of the crankcase 28 so as to form an obtuse angle with the axis of the cylinder block 27 in a plane perpendicular to the axis of the crankshaft 32, The air-fuel mixture can be efficiently sucked from the intake port 98 into the crankcase 28 when the air-fuel mixture is moved. In addition, since the support shaft 23 of the link mechanism 24 that supports the power unit P to the vehicle body frame F is disposed at a position sandwiched between the cylinder block 27 and the intake port 98, the length from the contact point of the rear wheel Wr to the support shaft 23 is set. Can be set relatively long, the vertical swing angle of the power unit P can be kept relatively small, and the overall height of the engine E can be kept relatively low so that the arrangement of the intake system such as the carburetor 80 and the air cleaner 81 can be reduced. The degree of freedom described above can be increased, and the volume of the article storage room 22 can be increased. In addition, since the oil pump 105 is disposed so as to be mostly accommodated in the recess 101 provided in the crankcase 28 below the intake pipe 99, the connection of the intake pipe 99 to the intake port 98 The oil pump 105 does not impose any restrictions on the arrangement of 99, and the degree of freedom in the arrangement of the intake system is further increased.
[0040]
Further, the coating 106 is formed on the input shaft 104 of the oil pump 105 by plating with a material having self-lubricating properties, for example, a material containing a fluorine resin, so that the screw gear 103 of the input shaft 104 and the crankshaft 32 Even if the meshing portion with the screw gear 102 is in the crankcase 28 where lubrication by the lubricating oil in the transmission case 64 cannot be expected, sufficient lubrication can be obtained. Therefore, the degree of freedom in the arrangement of the meshing portion, that is, the oil pump 105 can be increased.
[0041]
As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.
[0042]
【The invention's effect】
As described above, according to the present invention, the intake port provided on the upper part of the crankcase of the engine and opened on the upper surface of the case is arranged near the cylinder axis in plan view (that is, near the center in the left-right direction of the engine). Since the center intake system is used, intake resistance can be reduced by smoothly introducing intake air from the intake port to the interior of the engine without disturbing the crank web.In addition, this intake port has a cylinder axis that is almost horizontal to the port axis. Are provided so as to form an obtuse angle with each other in a plane perpendicular to the axis of the crankshaft, and the power unit is swingably supported on the body frame at a position sandwiched between the intake port and the cylinder block. Set a relatively long distance from the ground contact point of the rear wheel to the swing fulcrum while avoiding mutual interference with the intake system without difficulty. Te can be suppressed relatively small vertical swing angle of the power unit, while suppressing the overall height of the engine relatively low it is possible to increase the degree of freedom in arrangement of the intake system while achieving a volume increase of the article storage compartment. In addition, an air cleaner extending rearward from the rear end of the power unit and a carburetor connected to the air outlet of the air cleaner and inclined inward toward the front of the vehicle are disposed above the power unit. Between the intake port,In plan viewSince the connection is made by the intake pipe having an obtuse-angled bent portion, the length of the intake pipe can be secured sufficiently long, and the obtuse angle of the bent portion of the intake pipe can be made sufficiently large in combination with the use of the center intake system. Therefore, the intake resistance of the intake pipe can be effectively reduced, which can contribute to an improvement in the output performance of the engine.
[0043]
Furthermore, since the air guide duct that guides the air that has cooled the engine to the carburetor and the cover that is connected to the air cleaner and covers the outside of the carburetor are integrally connected, the air guide duct and the cover are shared. To protect the carburetor against external environmental factors such as rainfall, splashes and running wind, thereby improving the durability of the carburetor against the external environmental factors. With the cover (air cleaner), a clean and unified feeling of appearance can be obtained. Moreover, since the exhaust air that has passed through the engine is guided to the carburetor by the air guide duct, it is not necessary to dispose the carburetor close to the shroud of the engine, and it is possible to eliminate restrictions on arranging the carburetor. As a result, the carburetor can be arranged as far away from the intake port as possible as far as possible, which also makes it possible to secure a sufficiently long intake pipe, which can further contribute to improving the output performance of the engine.
[0044]
According to the second aspect of the present invention, the intake pipe is vertically arranged on one side of the intake port with the auxiliary device provided on the upper part of the crankcase and interlocking with the crankshaft. Despite the adoption of the intake system, the intake pipe connected to the intake port can be easily routed without interfering with the rear wheels immediately after the engine or the accessories on the top of the crankcase, and without displacing the engine to the front. It becomes possible.
[0045]
According to the third aspect of the present invention, since the accessory is accommodated in the recess provided on the upper surface of the crankcase at a position below the intake pipe, the accessory is kept as much as possible even if the accessory is provided on the upper part of the crankcase. Therefore, despite the fact that the auxiliary equipment and the intake pipe are arranged side by side, the restrictions imposed by the auxiliary equipment on the arrangement of the intake pipe can be suppressed as much as possible. The degree of freedom in the arrangement of the elements further increases.
[0046]
According to the fourth aspect of the present invention, since the filter medium accommodated in the air cleaner is disposed on the rear side of the vehicle body from the rear end of the article storage chamber, even if the filter medium in the air cleaner is enlarged, The capacity of the article storage room can be sufficiently secured without being affected by the above.
[Brief description of the drawings]
FIG. 1 is a side view of a scooter type motorcycle.
FIG. 2 is a plan view as viewed in the direction of arrow 2 in FIG.
FIG. 3 is an enlarged view of a main part of FIG. 1;
FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. 3;
FIG. 5 is a partially cutaway longitudinal sectional view taken along line 5-5 in FIG. 4;
FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 5;
FIG. 7 is a view taken along line 7-7 in FIG. 4;
8 is a sectional view taken along line 8-8 of FIG. 7;
FIG. 9 is a sectional view taken along line 9-9 of FIG. 7;
FIG. 10 is a sectional view taken along line 10-10 of FIG. 7;
FIG. 11 is a sectional view taken along line 11-11 of FIG. 7;
FIG. 12 is an enlarged sectional view taken along line 12-12 of FIG. 3;
FIG. 13 is an enlarged sectional view taken along line 13-13 of FIG. 4;
FIG. 14 is an enlarged sectional view showing an input shaft of the oil pump.
[Explanation of symbols]
20 sheets
22 Article storage room
26 cylinder block
28 crankcase
32 crankshaft
81 air cleaner
84          Filter media
89          Cover
92          Air duct
98          Intake port
99 Intake pipe
101 recess
105 Oil pump (auxiliary equipment)
E 2 cycle engine
F Body frame
M Continuously variable transmission as transmission mechanism
P power unit
V motorcycle
Wr rear wheel

Claims (4)

An article storage chamber (22) is provided below the seat (20), and a two-stroke engine (E) in which the axis of the crankshaft (32) is arranged in the lateral direction of the vehicle body has its cylinder axis substantially horizontal, and ), A rear wheel (Wr) is disposed behind the engine (E), and the engine (E) and the power of the engine (E) are transmitted to the rear wheel (Wr). In a motorcycle in which a power unit (P) constituted by a transmission mechanism (M) is swingably supported by a body frame (F),
An intake port (98), which is located near the cylinder axis in plan view and opens on the upper surface of the crankcase (28), is provided above the crankcase (28) of the engine (E) with the axis of the port (98). And the cylinder axis are formed so as to form an obtuse angle with each other in a plane perpendicular to the axis of the crankshaft (32),
At a position sandwiched between the intake port (98) and the cylinder block (27), the power unit (P) is swingably supported on the body frame (F),
Above the power unit (P), an air cleaner (81) extending rearward from the rear end of the unit (P), and a carburetor (80) connected to the air outlet of the air cleaner (81) and inclined inward in front of the vehicle. ), And the carburetor (80) and the intake port (98) are connected by an intake pipe (99) having a bend at an obtuse angle in plan view ,
A baffle duct (92) for guiding the air that has cooled the engine (E) to the carburetor (80), and a cover (89) connected to the air cleaner (81) and covering the outside of the carburetor (80). A motorcycle characterized by being integrally connected . The intake pipe (99) is vertically arranged on one side of the intake port (98) with an accessory (105) provided at an upper portion of the crankcase (28) and interlocking with the crankshaft (32). The motorcycle according to claim 1, wherein: Motorcycle according to claim 2, characterized in that the accessory (105) is accommodated in a recess (101) provided on the upper surface of the crankcase (28) at a position below the intake pipe (99). The filter medium (84) housed in the air cleaner (81) is arranged on the vehicle body rear side with respect to the rear end of the article storage chamber (22), according to claim 1, characterized in that: Motorcycle.

Images