JP3619290B2 - Small vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention comprises an engine having a crankshaft parallel to a rotation axis of a rear wheel and swingably connected to a vehicle body frame, and a transmission having an output shaft parallel to the crankshaft. The present invention relates to a small vehicle in which a rear wheel coupled to the output shaft is pivoted on a power unit disposed on the side of the vehicle.
[0002]
[Prior art]
Conventionally, such a vehicle is already known, for example, from Japanese Patent Application Laid-Open No. Sho 62-187684, in which the engine is disposed at the front position of the rear wheel and the output shaft of the transmission is from the center of rotation of the rear wheel. Is also arranged in the front, and a hanger provided on the crankcase of the engine is connected to the body frame.
[0003]
[Problems to be solved by the invention]
However, in the conventional device, the power unit occupies from the front position of the rear wheel to the vicinity of the rotation center of the rear wheel, and it is difficult to reduce the size of the power unit. Further, the distance between the center of rotation of the rear wheel and the hanger is restricted by the outer diameter of the rear wheel. In the conventional device, the power unit is further enlarged as the diameter of the rear wheel is increased.
[0004]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a small vehicle in which the cooling performance of the engine is improved after downsizing the power unit.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 includes an engine having a crankshaft parallel to a rotation axis of a rear wheel and swingably connected to a vehicle body frame, and an output parallel to the crankshaft. In a small vehicle in which a rear wheel connected to the output shaft is mounted on a power unit that is configured by a transmission having a shaft and is disposed on the side of the rear wheel, the output shaft of the transmission is a longitudinal direction of the vehicle Is arranged behind the rotation axis of the rear wheel and the crankshaft of the engine is arranged in front of the rotation axis of the rear wheel along the longitudinal direction of the vehicle,The engine is placed in a posture in which the axis of the cylinder is inclined forward, and the front end portion of the cylinder head is located in front of the rear wheel, and an intake passage is formed inside the cylinder head. The inlet pipe and the hanger that is integrally connected to the inlet pipe and swingably connected to the vehicle body frame at a position in front of the rear wheel so that there is no joint between the cylinder head, the inlet pipe, and the hanger. , Provided integrallyIt is characterized by that.
[0006]
In addition to the configuration of the invention according to claim 1, the invention according to claim 2The intake passage is curved in a U-shape when viewed from the side, and both ends open rearward, and the hanger extends in the lateral direction of the vehicle body on the side of the inlet pipe.It is characterized by that.
[0007]
The invention according to claim 3It consists of an engine having a crankshaft parallel to the rotation axis of the rear wheel and swingably connected to the vehicle body frame, and a transmission having an output shaft parallel to the crankshaft. In a small vehicle in which a rear wheel connected to the output shaft is mounted on a power unit to be disposed, the output shaft of the transmission is disposed behind the rotation axis of the rear wheel along the longitudinal direction of the vehicle. The crankshaft of the engine is disposed in front of the rotation axis of the rear wheel along the longitudinal direction of the vehicle, and a hanger provided on the cylinder head of the engine at the front position of the rear wheel is swingably connected to the body frame. ,The hanger is connected to the vehicle body frame at a position shifted to the opposite side of the engine with respect to the center in the width direction of the vehicle.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0009]
1 to 10 show an embodiment of the present invention. FIG. 1 is a side view of a scooter type motorcycle to which the present invention is applied. FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. Is a cross-sectional view taken along line 3-3 in FIG. 2, FIG. 4 is a side view showing a connection structure of the engine and the body frame, FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 7 is a diagram showing a transmission gear arrangement between the crankshaft and the rear wheel, FIG. 8 is a sectional view taken along line 8-8 in FIG. 3, FIG. 9 is an enlarged sectional view taken along line 9-9 in FIG. FIG. 10 is an enlarged vertical cross-sectional view of a main part of FIG. 9.
[0010]
First, in FIG. 1, the front part of a vehicle body frame 11 provided in a scooter type motorcycle V as a small vehicle is covered with a front cover 12 having a front fender 12a, and left and right turning operations by a steering handle 13 are performed. The front fork 14 is supported on the front end of the vehicle body frame 11 as possible. Thus, front wheel W_FIs covered with the front fender 12a and pivotally supported at the lower end of the front fork 14.
[0011]
The rear portion of the vehicle body frame 11 is covered with a rear cover 15, and a seat 17 is provided on the upper portion of the rear cover 15 for a passenger who puts his / her foot on the footrest step 16 to sit down. A power unit P is connected to the rear portion of the vehicle body frame 11 so as to be able to swing up and down, and a suspension spring 18 is provided between the power unit P and the vehicle body frame 11. Rear wheel W_RIs covered with a rear fender 19 extending rearward from the rear cover 15 and is pivotally mounted on the power unit P.
[0012]
By the way, the seat 17 is disposed at the upper part of the rear cover 15 so that it can be opened and closed by a hinge (not shown) provided at the front thereof, and the seat 17 covers a large size so that the upper end opening is covered. A box 60 is provided over almost the entire area of the rear cover 15. In addition, a sufficient distance is secured between the storage box 60 and the power unit P, and the cooling performance of the power unit P and the storage box 60 can be improved even though the storage box 60 is large.
[0013]
2 and 3, the power unit P includes a four-cycle air-cooled single-cylinder engine E and a hydrostatic continuously variable transmission M, and a rear wheel W on the left side facing the front of the motorcycle V._RIt is arranged on the side.
[0014]
Engine E is rear wheel W_RAxis of rotation C_WLeft and right crankcases 21 and 22 that rotatably support the crankshaft 20 parallel to the cylinder, and a cylinder block 24 that is coupled to the left and right crankcases 21 and 22 in common and is provided with a cylindrical cylinder 23; A combustion chamber 26 is formed between the piston 25 slidably fitted in the cylinder 23 and coupled to the cylinder block 24. The cylinder head 27 is coupled to the cylinder head 27 on the opposite side of the cylinder block 24. The piston 25 is connected to the crankshaft 20 via a connecting rod 29 and a crankpin 30. Thus, the engine E has the rear wheel W in a posture in which the axis of the cylinder 23 is inclined forward until it becomes substantially horizontal._RPlaced on the side ofAnd the front end of the cylinder head 27 is the rear wheel W. _R (Refer to FIGS. 1 and 2).
[0015]
A spark plug 31 that faces the combustion chamber 26 is detachably attached to the upper portion of the cylinder head 27, and an inlet pipe 34 that forms an intake passage 33 that can be switched between communication and disconnection to the combustion chamber 26 by the intake valve 32. It is provided seamlessly and integrally. The inlet pipe 34 is fixedly supported by the power unit P and is flange-coupled to an outlet pipe 36 of a carburetor 35 disposed above the cylinder head 27.As is clear from FIG.It has a substantially U-shaped vertical cross-sectional shape opened on the vaporizer 35 side.Both ends open backwardsIt is formed in the inlet pipe 34. The inlet of the vaporizer 35 is connected to an air cleaner 37. Further, an exhaust passage 39 is formed in the lower portion of the cylinder head 27 so that the exhaust valve 38 can be switched between communication and shut-off to the combustion chamber 26, and an exhaust pipe (not shown) is connected to the exhaust passage 39.
[0016]
A camshaft 41 is rotatably supported between the cylinder head 27 and a cam holder 40 coupled to the cylinder head 27. The camshaft 41 includes an intake cam 42 for driving the intake valve 32 to open and close, An exhaust cam 43 that drives the exhaust valve 38 to open and close is integrally provided.
[0017]
4 and 5 together, a hanger 45 integrally connected to the inlet pipe 34 is provided on the upper portion of the cylinder head 27.SeamlesslyThe hanger 45 is integrated with the rear wheel W._RFrom the cylinder head 27 of the engine E arranged on the left side of the rear wheel W_RIt is extended so that it may be located in front of. On the other hand, the vehicle body frame 11 has a pair of frame portions 11a and 11a spaced in the width direction of the motorcycle V at a position in front of the power unit P, and the hanger 45 prevents the frame portions 11a and 11a. They are connected via a vibration link 46.
[0018]
The anti-vibration link 46 includes a hollow cylindrical base portion 46a, a tip portion 46b having a hollow cylindrical shape smaller in diameter than the base portion 46a, and a pair of arms 46c and 46c that integrally couple the base portion 46a and the tip portion 46b. It consists of. Thus, the base portion 46a is supported on the first support shaft 48 that is horizontally fixed to the brackets 47, 47 provided on the both frame portions 11a, 11a of the vehicle body frame 11 via the rubber bushes 49, 49, respectively. . Further, the second support shaft 50 is inserted into the tip portion 46 b, and both end portions of the second support shaft 50 protruding from the tip portion 46 b are attached with rubber bushes 52, 52 to a pair of brackets 51, 51 provided on the hanger 45. It is supported through. Moreover, the connecting position of the hanger 45 to the vehicle body frame 11, that is, the center position between the brackets 51, 51 is shifted from the engine E with respect to the center C in the width direction of the motorcycle V by a distance δ.
[0019]
A pair of stoppers 53, 53 projecting to the opposite side of the arms 46c, 46c are fixed to the base portion 46a of the anti-vibration link 46, and the stoppers 53, 53 are formed to be tapered. On the other hand, support plates 54 are fixed to both frame portions 11a, 11a of the vehicle body frame 11, and in the pair of support boxes 55, 55 fixed to the support plates 54 and opened to the anti-vibration link 46 side. Stopper rubbers 56 and 56 are provided, and the tips of both stoppers 53 and 53 are inserted into the stopper rubbers 56 and 56.
[0020]
According to such a connection structure of the power unit P to the vehicle body frame 11, the power unit P can swing around the axis of the second support shaft 50, and the anti-vibration link 46 includes the rubber bushes 49, 49, 52, The vibration of the vibration isolation link 46 is attenuated by the stopper rubbers 56 and 56 and transmitted to the vehicle body frame 11 side while absorbing the vibration from the power unit P by 52. It will be.
[0021]
Referring again to FIG. 2, a bracket 57 is provided at the upper rear portion of the right crankcase 22, and the lower end portion of the suspension spring 18 is connected to the bracket 57 via a rubber bush 58.
[0022]
In FIG. 6, a mission case 61 is constituted by a case portion 21a provided integrally with the left crankcase 21, a case portion 22a provided integrally with the right crankcase 22, and a mission cover 62 coupled to the case portion 21a. The transmission case 61 includes a constant capacity swash plate hydraulic pump 63 and a variable capacity swash plate hydraulic motor 64 that forms a hydraulic closed circuit between the hydraulic pump 63. The continuously variable transmission M is accommodated. The hydraulic pump P includes an input cylinder shaft 71 that is rotatably supported by the case portion 22a of the right crankcase 22, a pump cylinder 146 that is rotatably supported by the input cylinder shaft 71, and a pump cylinder 146 that has A plurality of pump plungers 147... That are slidably fitted in an annular arrangement surrounding the rotation axis, a pump swash plate 148 that engages and abuts the front surface with the outer end of each pump plunger 147. A virtual trunnion axis O perpendicular to the axis of the input cylinder shaft 71 with respect to the swash plate 148₁And a pump swash plate holder 149 that is supported at an angle with respect to the axis of the pump cylinder 146. The pump swash plate holder 149 is formed integrally with the input cylinder shaft 71.
[0023]
The hydraulic motor 64 includes a motor cylinder 150 that is coaxially coupled to the pump cylinder 146, a plurality of motor plungers 151 that are slidably fitted to the motor cylinder 150 in an annular arrangement surrounding the rotation axis thereof, and each motor plunger. 151... A motor swash plate 152 that engages and abuts the front surface with the outer end of 151, a motor swash plate holder 153 that supports the motor swash plate 152, and a motor swash plate anchor that supports the back surface of the motor swash plate holder 153. 154. Opposing contact surfaces of the motor swash plate holder 153 and the motor swash plate anchor 154 are arranged such that the axis of the motor cylinder 150 and the trunnion axis O₂The motor swash plate holder 153 has a trunnion axis O.₂It is supported by a motor swash plate anchor 154 so as to be capable of relative rotation around it.
[0024]
The pump cylinder 146 and the motor cylinder 150 are integrally coupled to form a cylinder block 145, and an output shaft 72 that passes through the input cylinder shaft 71 coaxially and relatively rotatably is coupled to the cylinder block 145. The In addition, a ring 155 that forms an annular outer oil passage 156 between the cylinder block 145 and the cylinder block 145 is coupled to the outer periphery of the cylinder block 145. An oil passage 157 is formed.
[0025]
The pump cylinder 146 is provided with pumps for inhaling hydraulic oil from the inner oil passage 157 according to the suction operation of the pump plunger 147 and discharging hydraulic oil to the outer oil passage 156 according to the discharge operation of the pump plunger 147. A plurality of spool-type first distribution valves 158... Arranged radially corresponding to the plungers 147. In addition, the motor cylinder 150 is configured to supply hydraulic oil from the outer oil passage 156 accompanying the expansion operation of the motor plunger 151 and discharge hydraulic oil to the inner oil passage 157 accompanying the contraction operation of the motor plunger 151. A plurality of spool-type second distribution valves 159 arranged radially corresponding to the motor plungers 151 are slidably fitted.
[0026]
The first eccentric valve 161 surrounding the 158... At the outer end of the first distribution valve 158... And the second eccentric ring 162 surrounding the 159. , 164 are engaged. The first eccentric ring 161 is coupled to the input cylinder shaft 71, and the virtual trunnion axis O₁Are arranged eccentrically by a predetermined distance from the center of the cylinder block 145. The second eccentric ring 162 is coupled to the case portion 22a of the right crankcase 22, and the virtual trunnion axis O₂Are arranged eccentrically by a predetermined distance from the center of the cylinder block 145. Thus, the motor swash plate anchor 154 is coupled to the second eccentric ring 162.
[0027]
In such a hydrostatic continuously variable transmission M, the reaction torque received by the pump cylinder 146 from the pump swash plate 148 via the pump plunger 147 in the discharge stroke, and the motor cylinder 150 in the motor via the motor plunger 151 in the expansion stroke. The cylinder block 145 is rotated by the sum of the reaction torque received from the swash plate 152. In addition, the gear ratio of the output shaft 72 to the input cylinder shaft 71 changes depending on the capacity of the hydraulic motor 64, and the capacity of the hydraulic motor 64 is determined by the stroke of the motor plunger 151. The gear ratio can be changed steplessly by changing steplessly.
[0028]
A right crankcase cover 66 that forms a transmission gear chamber 65 between the right crankcase 22 and the outer surface thereof is coupled to the right crankcase 22, and a support plate 67 is coupled to the inner surface of the central portion of the right crankcase cover 66. Thus, along the longitudinal direction of the motorcycle V, the axis C of the crankshaft 20_CRotation axis C on the rear side_WThe axle 68 is rotatably supported by the right crankcase cover 66 and the support plate 67, and the rear wheel W together with the tire 70 is supported._RIs fixed to a protruding end portion of the axle 68 from the right crankcase cover 66. Moreover, a drum brake (not shown) is attached to the wheel 69, and the inner side of the drum brake is covered with the right crankcase cover 66.
[0029]
In the hydrostatic continuously variable transmission M, the input cylinder shaft 71, that is, the input end of the hydraulic pump 63, rotatably passes through the case portion 22a of the right crankcase 22 and protrudes into the transmission gear chamber 65. The output shaft 72 of the continuously variable transmission M, that is, the output end of the hydraulic motor 64 passes through the input shaft 71 coaxially and relatively rotatably, and projects into the transmission gear chamber 65. Moreover, the rotational axis C of the input shaft 71 and the output shaft 72_MIs the axis C of the crankshaft 20_CAnd the rear wheel W along the front-rear direction of the motorcycle V._RAxis of rotation C_WIt is arranged on the rear side. Therefore, rear wheel W_RAxis of rotation C_WIs the rotation axis C of the crankshaft 20_CAnd rotation axis C of transmission M_MArranged between them.
[0030]
Referring also to FIG. 7, the gear 73 coupled to the crankshaft 20 in the transmission gear chamber 65 is engaged with a gear 74 fixed to the input shaft 71 of the hydrostatic continuously variable transmission M. The gear 75 fixed to the output shaft 72 of the hydrostatic continuously variable transmission M is fixed to the transmission gear chamber 65 side end portion of the shaft 79 that is rotatably supported by the right crankcase cover 66 and the support plate 67. The gear 77 meshed with the gear 76 and fixed to the shaft 79 between the right crankcase cover 66 and the support plate 67 is connected to the rear wheel W._RIs engaged with a gear 78 fixed to the axle 68.
[0031]
Referring to FIGS. 8 and 9 together, a left crankcase cover 83 is coupled to the left crankcase 21, and the left crankcase 21, the transmission case 61, and the left crankcase cover 83 are surrounded around the crankshaft 20. A generator chamber 81 is formed therebetween, and a relatively narrow breather passage 82 is formed between the mission cover 62 and the left crankcase 21 and the left crankcase cover 83 in the mission case 61. In the generator chamber 81, a generator 84 having a rotor 85 fixed to the crankshaft 20 and a stator 86 fixed to the left crankcase cover 83 is accommodated. A breather hole 21b is provided in a portion of the left crankcase 21 that faces the generator chamber 81.
[0032]
The left crankcase cover 83 is integrally provided with a baffle plate 83a that faces the side surface of the mission cover 62 so as to partition the generator chamber 81 and the breather passage 82, and enters the generator chamber 81. The blow-by gas is guided to the breather passage 82 from the gap between the baffle plate 83a and the mission cover 62 as indicated by the broken-line arrows in FIG.
[0033]
On the other hand, a recess 87 for forming a breather main chamber 88 in cooperation with the mission case 61 and the left crankcase cover 83 is provided above the mission case 61 and above the left crankcase 21. The main chamber 88 communicates with the upper part of the breather passage 82. A breather pipe 89 having a lower end opened to the breather main chamber 88 is connected to the upper portion of the left crankcase 21, and the breather pipe 89 communicates with the air cleaner 37. Further, the left crankcase 21 and the mission cover 62 are provided with walls 90 and 91 for preventing the breather gas from the generator chamber 81 from being blown directly to the breather main chamber 88.
[0034]
Thus, the breather gas from the generator chamber 81 flows to the breather main chamber 88 side in the breather passage 82 as indicated by the broken arrow in FIG. 9. At this time, the inner surface of the left crankcase cover 83 and the mission cover 62 The mist accompanying the breather gas is separated from the breather gas due to the collision, and is moved downward along the outer surface of the mission cover 62 as shown by the solid line arrow in FIG. It will flow down.
[0035]
According to such a configuration, the breather passage 82 and the breather main chamber 88 can be formed by the left crankcase 21, the left crankcase cover 83, and the mission cover 62. Therefore, compared to the case where a labyrinth structure is obtained by forming a breather chamber between the two crankcases and forming a communication hole in the gasket sandwiched between the two crankcases, it is necessary to use dedicated parts for the breather. Therefore, the number of parts can be reduced, and the assembly can be automated by using a gasket as a liquid gasket. By the way, the lower portions of the left and right crankcases 21 and 22 and the lower portion of the left crankcase cover 83 function as an oil pan 92. In the oil pan 92, lubricating oil up to the liquid level L shown in FIG. The mist that has been stored and separated from the breather gas in the breather passage 82 falls to the oil pan 92 along the outer surface of the mission cover 62. Further, a level gauge 93 for detecting the liquid level L is attached to the left crankcase cover 83 so as to be detachable.
[0036]
The cylinder block 24, the cylinder head 27, and the head cover 28 are formed with a cam chain chamber 94 that communicates with the generator chamber 81 and extends in a substantially horizontal direction, and the generator chamber 81 has a space between the generator 84 and the left crankcase 21. An endless cam chain 97 wound around a drive pulley 95 fixed to the crankshaft 20 and a driven pulley 96 fixed to the camshaft 41 in the cam chain chamber 94 includes a generator chamber 81 and a cam chain chamber. 94 is stored so as to be able to run.
[0037]
An oil sump 98 is recessed in the bottom wall of the cam chain chamber 94, and the upper end of a hydraulic push rod 99 that extends vertically with the lower end immersed in the oil sump 98 is connected to the drive pulley 95 and the driven of the cam chain 97. The pulley 96 is connected to a tensioner member 100 that abuts from below on a portion that travels on the lower side between the pulleys 96.
[0038]
Referring also to FIG. 10, the oil sump 98 opens to the cylinder head 27 side and is provided in the lower portion of the cylinder block 24, and the oil reservoir 98 opens to the cylinder block 24 side and provided in the lower portion of the cylinder head 27. The recessed portion 27 a is formed, and is disposed at an upper position on the front side of the oil pan 92. Thus, the power unit P is swingably connected to the vehicle body frame 11 so that the rear part thereof is displaced up and down, and the lubricating oil is supplied from the oil pan 92 to the oil reservoir 98 by the swinging operation of the power unit P. Supplied.
[0039]
The hydraulic push rod 99 is slidable on the housing 101 by forming an oil chamber 102 between a bottomed cylindrical housing 101 that is screwed to the cylinder block 24 and extends upward, and a lower end closing portion of the housing 101. A cylindrical rod 103 fitted to the rod 103, a pressing member 105 coupled to the upper end of the rod 103 via a spring pin 104, a spring 106 contracted between the upper ends of the housing 101, and a lower portion of the pressing rod 103 The housing 101 is provided with a plurality of communication holes 108 through which the lubricating oil in the oil reservoir 98 is circulated, and the rod 103 also has a plurality of communication holes 109 that communicate with the communication holes 108. Is provided.
[0040]
The housing 101 is screwed into the lower part of the cylinder block 24 so that the upper end of the housing 101 protrudes above the oil level of the oil reservoir 98, and a seal member 111 is interposed between the housing 101 and the cylinder block 24. Be dressed.
[0041]
The check valve 107 has a valve seat 112 formed in a dish shape with a valve hole 112 in the center, and the valve seat member 113 is sandwiched between the rod 103 and the lower end portion of the rod 103. A dish-shaped cap 115 that is press-fitted and fixed and forms a valve chamber 114 between the valve seat member 113 and a spherical valve element 116 that is capable of closing the valve hole 112 and is accommodated in the valve chamber 114. The cap 115 is provided with a slit 117 that cannot be closed by the valve body 116 and always allows the valve chamber 114 to communicate with the oil chamber 102.
[0042]
The check valve 107 allows the lubricating oil to flow into the oil chamber 102 when the rod 103 moves upward by the spring force of the spring 106, but closes the valve hole 112 when the rod 103 is pressed downward to The chamber 102 is locked.
[0043]
The tensioner member 100 is formed in an arcuate shape so as to come into contact with a portion of the cam chain 97 that travels downward between the drive pulley 95 and the driven pulley 96 from below for a relatively long distance. Is pivotally supported on the left crankcase 21 by a support shaft 118 parallel to the crankshaft 20. Further, the pressing member 105 of the hydraulic push rod 99 is brought into contact with the lower portion of the tensioner member 100.
[0044]
According to such a configuration, the tensioner member 100 is pushed up so as to apply tension to the cam chain 97 by the spring 106 of the hydraulic push rod 99, and the reaction force from the cam chain 97 is acted on by the check valve 107. When 102 is locked, it is received by the hydraulic push rod 99 when the rod 103 is stepped on. 3 and 8, particularly, a kick spindle 120 having an axis parallel to the crankshaft 20 is rotatably supported at the lower front portions of the left and right crankcases 21 and 22, and the left crankcase 21 A kick pedal 121 extending forward is fixed to the end of the kick spindle 120 that protrudes outward from the front. A kick spindle gear 122, which is a sector gear, is fixed to the kick spindle 120 between the left and right crankcases 21 and 22, and a gear train 123 including the kick spindle gear 122 is connected to the crankshaft 20 via the start clutch 124. Connected. Further, a torsion spring 125 is provided between the left crankcase 21 and the kick spindle gear 122, and this torsion spring 125 causes the kick pedal 121, that is, the kick spindle 120 to return to the original state when the depression operation of the kick pedal 121 is completed. Demonstrates spring force to return to position.
[0045]
By the way, the cylinder block 24 and the cylinder head 27 are formed with a gear chamber 126 communicating with the lower part between the left and right crankcases 21 and 21, extending in the axial direction of the cylinder 23, that is, substantially in the horizontal direction. A part of the kick spindle gear 122 is operably stored in the gear chamber 126 and is disposed at the lower front part of the left and right crankcases 21 and 22.
[0046]
The gear train 123 includes a kick spindle gear 122, a gear 127 that meshes with the kick spindle gear 122, and a gear 128 that is coaxial with the gear 127. The gears 127 and 128 are integrally formed. It is formed and is rotatably supported by a shaft 129 provided between the left and right crankcases 21 and 22. Moreover, the gear train 123 is arranged substantially along the axis of the cylinder 23.
[0047]
The start clutch 124 is provided between a left crankcase 21 and a right crankcase cover 66 and includes a support shaft 130 having a flange 130a at an end on the right crankcase cover 66 side, and a stopper 131a facing the flange 130a. And a slide shaft 131 supported on the support shaft 130 so as to be axially slidable, and provided at an end portion of the slide shaft 131 on the left crankcase 21 side and meshed with a gear 128 of the gear train 123. The base end of the gear 132, the spring 133 that is contracted between the support shaft 130 and the sliding shaft 131 by exerting a spring force in the direction of separating the stopper 131a from the flange portion 130a, and the right crankcase 22. A pinch spring 134 that is stopped and frictionally engaged with the sliding shaft 131, and a gear 135 that is fixed to the sliding shaft 131 near the stopper 131a; And a gear 136 that is coupled to a crankshaft 20 as an enable engagement of the gear 135.
[0048]
The gear 128 of the gear train 123 and the gear 132 provided on the slide shaft 131 are helical gears. When rotational power from the gear train 123 is applied to the slide shaft 131, the pinion spring 134 causes the slide shaft 131 to move to the slide shaft 131. Since the rotational resistance is given, the sliding shaft 131 slides in a direction in which the stopper 131a is brought close to the flange portion 130a against the spring force of the spring 133, and the sliding shaft 131 is slid. As a result, the gear 135 meshes with the gear 136 of the crankshaft 20, so that rotational power is transmitted to the crankshaft 20.
[0049]
Incidentally, a starter motor 137 is attached to the right crankcase 22, and an output gear 138 provided on the output shaft of the starter motor 137 includes a gear 139, a gear 140 integrated with the gear 139, and an overrunning clutch. It is connected to the crankshaft 20 via 141.
[0050]
Therefore, it is possible to select one of starting the engine E by depressing the kick pedal 121 and starting the engine E by operating the starter motor 137.
[0051]
Next, the operation of this embodiment will be described. In the power unit P, the output shaft 72 of the hydrostatic continuously variable transmission M is arranged in the rear wheel W along the front-rear direction of the motorcycle V._RAxis of rotation C_WThe rear side of the rear wheel W_RAxis of rotation C_WThe rear wheel W_RIt is arranged on the side of Therefore, the rear wheel W_RThe power unit P can be compactly gathered on the side of the power unit P, and the power unit P can be further downsized by using the hydrostatic continuously variable transmission M as a transmission. Rear wheel W_RAs a result of the power unit P being on the side of the motorcycle, the traveling wind of the motorcycle V and the rear wheel W_RThe power unit P can be effectively cooled by the wind generated by.
[0052]
Moreover, the cylinder head 27 of the engine E has a rear wheel W._RA hanger 45 is provided so as to be located in front of the hanger 45, and the hanger 45 is connected to the vehicle body frame 11 via a vibration isolation link 46. Therefore, the cylinder block 24 of the engine E can be provided with a function as a rear fork, so that the entire length of the engine E can be used effectively, whereby the power unit P can be further downsized. Further, by providing the cylinder head 27 with the hanger 45, the surface area of the cylinder head 27 can be increased, and the cooling performance can be further improved.
[0053]
The hanger 45 is formed integrally with an inlet pipe 34 that is formed integrally with the cylinder head 27 by forming an intake passage 33, and a separate inlet pipe that connects between the carburetor 35 and the engine E is provided. It becomes unnecessary and can contribute to the reduction of the number of parts, and the inlet pipe 34 can improve the strength of the portion where the hanger 45 is connected to the cylinder head 27.
[0054]
Further, the hanger 45 is connected to the vehicle body frame 11 at a position shifted by a distance δ on the opposite side to the engine E with respect to the center C in the width direction of the motorcycle V._RThe stability of the straight movement stability due to the tilt of the vehicle body caused by the twist of the power unit P arranged on the side of the hull is canceled by the generation of the moment due to the deviation to improve the steering stability and the rigidity of the hanger 45 is set large. Accordingly, the hanger 45 can be reduced in size and weight.
[0055]
By the way, rear wheel W_RThe engine E in the power unit P arranged on the side of the_CRear wheel W_RAxis C_WThe kick spindle 120 is disposed at the lower front part of the left and right crankcases 21 and 22 in such an engine E. A gear train 123 including the kick spindle gear 122 is arranged substantially along the axis of the cylinder 23, and the cylinder block 24 is provided with a gear chamber 126 in which a part of the kick spindle gear 122 is operably accommodated. Therefore, engine E is rear wheel W_RThe kick spindle 120 can be disposed as far forward as possible even if it is disposed on the side of the engine, and the kick startability can be improved while avoiding the enlargement of the engine E.
[0056]
Further, of the cam chain 97 that travels in the cam chain chamber 94 that extends substantially horizontally along the axis of the cylinder 23, the tensioner member 100 abuts on the portion that travels downward between the drive pulley 95 and the driven pulley 96 from below. The tensioner member 100 is pressed upward by the hydraulic push rod 99. For this reason, a complicated structure such as a link mechanism is not required, the number of parts of the mechanism for tensioning the cam chain 97 is relatively small, noise generation due to rattling of each part is suppressed as much as possible, and the weight of the mechanism is reduced. It is possible to reduce the size of the engine E with a simple configuration.
[0057]
The hydraulic push rod 99 has a lower end immersed in an oil reservoir 98 that is recessed in the bottom wall of the cam chain chamber 94. The hydraulic push rod 99 is configured so that the lubricating oil is well stored in the oil reservoir 98. The operability and durability of can be improved. Moreover, the oil sump 98 is formed by a recess 24 a provided in the lower part of the cylinder block 24 that opens to the cylinder head 27 side, and a recess 27 a provided in the lower part of the cylinder head 27 that opens to the cylinder block 24 side. Is. Accordingly, an oil sump 98 is formed by the coupling of the cylinder block 24 and the cylinder head 27, and the recesses 24a and 27a are along the die-cutting direction of the cylinder block 24 and the cylinder head 27 to be cast, so that the cylinder The oil sump 98 can be formed without the need for post-processing of the block 24 and the cylinder head 27 after casting, and the depths of the recesses 24a and 27a along the longitudinal direction of the cam chain chamber 94 can be freely set. Thus, the capacity of the oil sump 98 can be set relatively freely.
[0058]
Further, since the lubricating oil can be supplied from the oil pan 92 to the oil reservoir 98 as the power unit P swings, the initial oil supply to the oil reservoir 98 after assembly and the oil supply during operation can be performed by the swinging of the power unit P. In particular, it is not necessary to supply oil to the oil reservoir 98.
[0059]
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.
[0060]
For example, the present invention can be applied to a scooter-type motor tricycle.
[0061]
【The invention's effect】
Claim 1 as described above, 2 eachAccording to the invention, the output shaft of the transmission is disposed behind the rotation axis of the rear wheel along the longitudinal direction of the vehicle, and the crankshaft of the engine is located along the longitudinal direction of the vehicle with respect to the rotation axis of the rear wheel. Placed forward,The engine is placed in a posture in which the axis of the cylinder is inclined forward, and the front end portion of the cylinder head is located in front of the rear wheel, and an intake passage is formed inside the cylinder head. The inlet pipe and the hanger that is integrally connected to the inlet pipe and swingably connected to the vehicle body frame at a position in front of the rear wheel so that there is no joint between the cylinder head, the inlet pipe, and the hanger. , Provided integrallyTherefore, it is possible to effectively cool by running wind and wind generated by the rear wheel, and by effectively increasing the surface area of the cylinder head, the power unit can be compactly combined to the side of the rear wheel.. Moreover, what is a cylinder head?Separate inlet pipe・ HangerThis can contribute to a reduction in the number of parts, and can improve the strength of the portion of the hanger connected to the cylinder head.
[0062]
In particular, according to the invention of claim 2,The inlet passage of the inlet pipe is curved in a U-shape when viewed from the side, and both ends open rearward, and the hanger extends in the left-right direction of the vehicle body at the side of the inlet pipe..
[0063]
AlsoInvention of Claim 3According to the present invention, the output shaft of the transmission is a rotating shaft of the rear wheel along the longitudinal direction of the vehicle. A hanger provided on the cylinder head of the engine at a position in front of the rear wheel, the crankshaft of the engine being arranged behind the line and the crankshaft of the engine is arranged in front of the rotational axis of the rear wheel along the longitudinal direction of the vehicle. Since it is swingably connected to the body frame, it can be effectively cooled by the wind generated by the running wind and the rear wheels, and by effectively increasing the surface area of the cylinder head, the power unit can be mounted on the rear wheel side. Can be put together in a compact way. Also especiallySince the hanger is connected to the vehicle body frame at a position shifted to the opposite side of the engine with respect to the center in the width direction of the vehicle, the straight running stability due to the inclination of the vehicle body caused by the twist of the power unit arranged on the side of the rear wheel Disturbances can be canceled by the generation of moments due to the above-mentioned deviations, and it is possible to improve steering stability and to reduce the size and weight of the hanger without the need to increase the rigidity of the hanger.
[Brief description of the drawings]
FIG. 1 is a side view of a scooter type motorcycle.
2 is an enlarged sectional view taken along line 2-2 of FIG.
3 is a cross-sectional view taken along line 3-3 in FIG.
FIG. 4 is a side view showing a connection structure between an engine and a body frame.
5 is a cross-sectional view taken along line 5-5 of FIG.
6 is an enlarged cross-sectional view taken along line 6-6 of FIG.
FIG. 7 is a diagram showing a transmission gear arrangement between a crankshaft and a rear wheel.
8 is a cross-sectional view taken along line 8-8 of FIG.
9 is an enlarged cross-sectional view taken along line 9-9 of FIG.
10 is an enlarged vertical cross-sectional view of a main part of FIG. 9;
[Explanation of symbols]
11 ... Body frame
20 ... Crankshaft
27 ... Cylinder head
33 ... Intake passage
34 ... Inlet pipe
45 ... hangers
72 ... Output shaft
C: Center in the width direction of the vehicle
C_W... Rear wheel rotation axis
E ... Engine
M: Transmission
P ... Power unit
V ... Motorcycle as a small vehicle
W_R···Rear wheel

Claims (3)

An engine (E) having a crankshaft (20) parallel to the rotational axis (C _W ) of the rear wheel (W _R ) and swingably connected to the vehicle body frame (11), and the crankshaft (20) And a transmission unit (M) having an output shaft (72) parallel to the rear and connected to the output shaft (72) to a power unit (P) disposed on the side of the rear wheel (W _R ). In a small vehicle on which a wheel (W _R ) is pivoted,
The output shaft (72) of the transmission (M) is disposed behind the rotational axis (C _W ) of the rear wheel (W _R ) along the longitudinal direction of the vehicle (V), and the crankshaft of the engine (E) (20) is arranged in front of the rotational axis (C _W ) of the rear wheel (W _R ) along the longitudinal direction of the vehicle (V), and the engine (E) inclines the axis of the cylinder (23) forward. The front end of the cylinder head (27) is positioned in front of the rear wheel (W _R ), and an intake passage (33) is provided at the upper part of the cylinder head (27). An inlet pipe (34) formed inside, and a hanger (45) that is connected to the inlet pipe (34) and is swingably connected to the vehicle body frame (11) at a position in front of the rear wheel (W _R ). The cylinder head (27), the inlet pipe (34 Small vehicles as seamless therebetween, and which are located in the integral and hanger (45). The intake passage (33) is curved in a U-shape when viewed from the side, and both ends open rearward, and the hanger (45) extends laterally on the side of the inlet pipe (34). wherein the is a small vehicle according to claim 1. An engine (E) having a crankshaft (20) parallel to the rotation axis (C _W ) of the rear wheel (W _R ) and swingably connected to the vehicle body frame (11), and the crankshaft (20) And a transmission unit (M) having an output shaft (72) parallel to the rear and connected to the output shaft (72) to a power unit (P) disposed on the side of the rear wheel (W _R ). In a small vehicle on which a wheel (W _R ) is pivoted,
The output shaft (72) of the transmission (M) is disposed behind the rotational axis (C _W ) of the rear wheel (W _R ) along the longitudinal direction of the vehicle (V) and the crankshaft of the engine (E) (20) is disposed in front of the rotation axis (C _W ) of the rear wheel (W _R ) along the longitudinal direction of the vehicle (V), and the cylinder of the engine (E) is positioned in front of the rear wheel (W _R ). A hanger (45) provided on the head (27) is swingably connected to the body frame (11), and the hanger (45) is connected to the engine (E) with respect to the center (C) in the width direction of the vehicle (V). small-type vehicle, characterized in that it is connected to the vehicle body frame (11) at a position shifted to the opposite side.

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