CN1962350A - two-wheeled motor vehicle - Google Patents

Abstract

A two-wheeled motor vehicle, a radiator and a thermostat are arranged on one side of an engine body having a cooling water jacket and mounted on a vehicle frame, and the thermostat controls the cooling water discharged from the cooling water jacket to the radiator Of the flow rate, where the radiator and thermostat are covered from the outside, the number of parts and installation man-hours can be reduced. The radiator (162) and the thermostat (175) arranged at approximately the same position as the radiator core (166) of the radiator (162) along the width direction of the vehicle frame are covered from the outside by a common radiator cover .

Description

two-wheeled motor vehicle

technical field

The present invention relates to a two-wheeled motor vehicle. A radiator and a thermostat are arranged on one side of an engine body having a cooling water jacket and mounted on a vehicle frame. The thermostat controls the discharge from the cooling water jacket to the radiator. flow of cooling water.

Background technique

For example, such a two-wheeled motor vehicle as described in Patent Document 1 is known.

Patent Document 1: JP-A-2003-170792

However, in the motorcycle disclosed in Patent Document 1, the radiator is covered by the radiator cover from the outside, and the thermostat is covered by the thermostat cover from the outside, which increases the number of parts and increases the man-hours for installation.

Contents of the invention

The present invention was developed in view of the related problems, and an object of the present invention is to provide a two-wheeled vehicle that covers a radiator and a thermostat from the outside, which can reduce the number of parts and the man-hours for installation.

In order to achieve the above object, the two-wheeled motor vehicle according to the first aspect of the present invention is equipped with a radiator and a thermostat on the side of the engine body that has a cooling water jacket and is mounted on the vehicle frame. The flow rate of the cooling water discharged to the radiator is characterized in that the radiator and the radiator core arranged at substantially the same position as the radiator core of the radiator along the width direction of the vehicle frame The thermostat is covered from the outside by a common radiator cover.

In addition, in the second aspect of the present invention, based on the first aspect, the exhaust pipe connected to the cylinder head of the engine body extends rearward through the bottom of the engine body, and covers at least a part of the exhaust pipe from the outside. The exhaust pipe cover portion is integrally provided on the radiator cover.

Furthermore, in a third aspect of the present invention, based on the first aspect or the second aspect, the thermostat is installed on a pump casing of a cooling water pump installed on the engine main body.

According to the first aspect of the present invention, since the radiator core and the thermostat of the radiator are arranged at approximately the same position along the width direction of the vehicle frame, the radiator and the thermostat are covered from the outside by a common radiator cover. Since the radiator and thermostat are covered from the outside, it is possible to reduce the number of parts and the number of installation man-hours.

In addition, according to the second aspect of the present invention, in addition to the radiator and the thermostat, the radiator cover also covers at least a part of the exhaust pipe below the engine main body from the outside, so that the number of parts can be further reduced.

According to the third aspect of the present invention, the cooling water pump is installed on the engine main body, and the thermostat is installed on the pump casing of the cooling water pump, whereby the constant temperature at approximately the same position as the radiator core along the width direction of the vehicle frame can be effectively utilized. By disposing the cooling water pump in the space between the engine and the engine body, the layout around the engine can be miniaturized.

Description of drawings

Fig. 1 is the side view of scooter type vehicle;

Figure 2 is an enlarged view of the main part of Figure 1;

Fig. 3 is the 3-3 line sectional view of Fig. 2;

Figure 4 is an enlarged view of the main part of Figure 2;

Fig. 5 is a side view corresponding to Fig. 4 with the radiator cover removed;

Fig. 6 is a perspective view of the exhaust purification device;

Fig. 7 is the 7 direction view of Fig. 4;

Fig. 8 is an enlarged transverse sectional view showing the vicinity of the driven pulley of the continuously variable transmission;

Figure 9 is an enlarged left side view of the air filter;

Fig. 10 is a view from direction 10 of Fig. 9;

Figure 11 is an enlarged sectional view of line 11-11 of Figure 9;

Fig. 12 is a sectional view of line 12-12 of Fig. 11;

Fig. 13 is a sectional view of line 13-13 of Fig. 4;

Fig. 14 is a cross-sectional view showing the main body of the engine along line 14-14 of Fig. 5 and showing the radiator upright in order to show the water circulation path;

Fig. 15 is a partial cutaway side view of the fan cover viewed from the direction of the arrow 15-15 in Fig. 13;

Fig. 16 is a view from the arrow 16 in Fig. 15 .

reference sign

21: Frame

30: Engine main body

33: cylinder head

50: exhaust pipe

148: Cooling water pump

151: pump housing

158: cooling water jacket

162: Radiator

165: radiator core

168: Radiator cover

168a: Exhaust pipe cover

175: Thermostat

Detailed ways

Hereinafter, an embodiment of the present invention will be described based on an example of the present invention shown in the drawings.

Fig. 1～Fig. 16 represent an embodiment of the present invention, Fig. 1 is the side view of scooter type vehicle, Fig. 2 is the enlarged view of the main part of Fig. 1, Fig. 3 is the 3-3 line sectional view of Fig. 2, Fig. 4 is an enlarged view of the main part of FIG. 2, FIG. 5 is a side view corresponding to FIG. 4 with the radiator cover removed, FIG. 6 is a perspective view of the exhaust purification device, and FIG. 8 is an enlarged transverse sectional view showing the vicinity of the driven pulley of the continuously variable transmission, FIG. 9 is an enlarged left side view of the air filter, FIG. 10 is a view from the direction of 10 in FIG. Figure 9 is an enlarged cross-sectional view of line 11-11, Figure 12 is a cross-sectional view of line 12-12 in Figure 11, Figure 13 is a cross-sectional view of line 13-13 in Figure 4, and Figure 14 is a cross-sectional view along line 14-14 in Figure 5 It shows the sectional view of the main body of the engine and shows the radiator upright in order to show the water circulation path. FIG. 15 is a partially cutaway side view of the fan cover viewed from the direction of the arrow 15-15 in FIG. 13 , and FIG. directional view.

In the following description, front and rear and left and right are described based on the traveling direction of the scooter-type vehicle.

First, in FIG. 1 , a vehicle frame 21 of a scooter type vehicle as a two-wheeled motor vehicle is composed of a front frame 22 extending forward and downward from a front pipe 25 and supporting a pedal 26 , and a rear frame 23 . , the front tube 25 can steerably support the front fork 24, the front fork 24 pivotally supports the front wheel WF, and the rear frame 23 extends rearward and upward from the rear of the front frame 22 and supports the passenger Use seat 27. The power unit P is suspended on the vehicle frame 21 so as to be able to swing up and down via the suspension link 28. The power unit P pivotally supports the rear wheel WR and drives the rear wheel WR. The up and down swing of the unit P is buffered by the rear buffer 29 .

In FIGS. 2 and 3 , the engine E of the power unit P has, as the engine main body 30 , a crankcase 31 , a cylinder block 32 connected to the front end of the crankcase 31 in a forward leaning position, and a cylinder head 33 connected to the front end of the cylinder block 32 . .

A crankshaft 35 having an axis extending in the left-right direction is rotatably supported by the crankcase 31 , and a piston 37 slidably fitted to a cylinder bore 36 included in the cylinder block 32 is connected to the crankshaft via a connecting rod 38 and a crankpin 39 . 35, a spark plug 40 is installed on the cylinder head 33, and a valve train 41 with a camshaft 65 with a decompression device 34 is configured, and a cover 42 covering the valve train 41 is combined on the front end of the cylinder head 33.

The crankcase 31 is configured by combining left and right case half bodies 31L, 31R divided left and right by a vertical plane including the axis line of the cylinder bore 36 . The crankshaft 35 rotatably penetrates the left and right case halves 31L, 31R, and ball bearings 43 , 44 are mounted between the case halves 31L, 31R and the crankshaft 35 , respectively.

Referring to Fig. 4 and Fig. 5 at the same time, an air filter 45 is disposed above the power unit P, and the air filter 45 passes through a carburetor 47, an air intake pipe 48 and an air inlet provided on the upper side of the cylinder head 33. 46 (refer to Figure 14) connection. In addition, an exhaust port 49 is provided on the lower side of the cylinder head 33, and an exhaust pipe 50 whose upstream end is connected to the exhaust port 49 extends downward from the cylinder head 33 and extends backward through the lower front portion of the power unit P. The downstream end of the exhaust pipe 50 is connected to an exhaust muffler 51 arranged on the right side of the rear wheel WR.

Referring to Fig. 6 at the same time, the exhaust gas discharged from the exhaust port 49 is purified by an exhaust purification device 54, which introduces secondary air into the exhaust gas, and has: a resonator 56, which has a front The intake pipe 55 of the opening is supported on the rear frame 23; the secondary air filter 58 is connected to the middle of the intake pipe 55 via the pipeline 57; the secondary air control valve 59 is used according to the intake vacuum. Pressure to control the air flow, connected to the secondary air filter 58; reed valve 60, which only allows flow from the secondary air control valve 59 side, connected to the secondary air control valve 59; rubber hose 61 , which introduces the air from the reed valve 60, and the upstream end is connected to the reed valve 60; the metal connecting pipe 62, whose upstream end is connected to the flexible pipe 61, is introduced into the secondary air control valve 59 into the intake vacuum pressure The vacuum pressure discharge pipeline 63 is connected with the intake pipe 48.

In FIG. 7 , the downstream end of the connection pipe 62 is connected to the cylinder head 33 in communication with the passage 69 , and the passage 69 is provided in the cylinder head 33 in communication with the exhaust port 49 . A part of the connection pipe 62 is formed with a substantially U-shaped U-shaped portion 62 a that is disposed between the lower side of the cylinder head 33 and the exhaust pipe 50 as viewed from the side. Furthermore, as shown in FIG. 7 , a part of the U-shaped portion 62 a is located between the lower side surface of the cylinder head 33 and the exhaust pipe 50 .

Returning to Fig. 3 again, a drive sprocket 64 is fixed on the crankshaft 35 on the outside of the ball bearing 43 installed between the left half body 31L of the crankcase 31 and the crankshaft 35, and the driven sprocket 66 is fixed. An endless timing chain 67 is wound around the drive sprocket 64 and the driven sprocket 66 on the camshaft 65 included in the valve train 41 . Furthermore, a chain passage 68 for operating the timing chain 67 is provided in the left case half body 31L, the cylinder block 32 and the cylinder head 33 .

In addition, a transmission case 71 is connected to the left case half 31L so as to extend to the left side of the rear wheel WR.

The transmission case 71 is composed of an inner case 72, an outer case 73, and a reduction gear case 74. The inner case 72 protrudes further than the outer side of the cylinder block 32 along the axis of the crankshaft 35 and extends rearward, and is integrally provided on On the left box half 31L of the crankcase 31, the outer box 73 is combined with the inner box 72 from the left side, and the reduction gear box 74 is combined with the right rear part of the inner box 72. A transmission chamber 75 as a dry space is formed between the inner case 72 and the outer case 73, and a speed reducer chamber 76 isolated from the transmission chamber 75 is formed between the inner case 72 and the reduction gear case 74, and engine oil is stored in the speed reducer chamber 76. The axle shaft 77 of the rear wheel WR is rotatably supported by the rear part of the inner case 72 of the transmission case 71 and the reduction gear case 74 .

The transmission T consists of a V-belt type continuously variable transmission 78 housed in the transmission chamber 75 , and a gear reduction mechanism provided between the continuously variable transmission 78 and the axle 77 and housed in the speed reducer chamber 76 . 79 compositions.

The crankshaft 35 protrudes into the transmission chamber 75 through the left case half body 31L in a liquid-tight and rotatable manner on the outside of the drive sprocket 64 . The pulley 80 and the driven pulley 83 having an axis parallel to the crankshaft 35 and attached to the driven shaft 81 rotatably supported by the transmission case 71 via a centrifugal clutch 82 are wound around the drive pulley 80 and the driven belt. The endless V-belt 84 on the wheel 83.

The drive pulley 80 consists of a fixed pulley half 85 fixed to one end of the crankshaft 35 , and a movable pulley half slidably mounted on the crankshaft 35 axially inside the fixed pulley half 85 . body 86, and a V-shaped belt 84 is wound in a V-shaped annular groove 87 formed between the two pulley halves 85,86. In addition, a swash plate 88 is fixed to the crankshaft 35 on the back side of the movable sheave half body 86, and a plurality of weight wheels 89 are accommodated in a floating state between the movable sheave half body 86 and the swash plate 88. . Then, when the rotational speed of the crankshaft 35 is increased, the weight pulley 89 . Accordingly, the contact radius between the V-belt 84 and the pulley halves 85 and 86 becomes large.

The driven shaft 81 penetrates the inner case 72 in a fluid-tight manner and rotatably, one end of the driven shaft 81 is rotatably supported by the outer case 73 via a ball bearing 90 , and the other end of the driven shaft 81 is rotatable via a ball bearing 91 It is supported by the reduction gear case 74 , and the middle portion of the driven shaft 81 is rotatably supported by the inner case 72 via a ball bearing 92 .

In FIG. 8, a cylindrical bush 93 is mounted on one end of the driven shaft 81. The bush 93 is made of porous sintered alloy and is impregnated with engine oil. Further, the bush 93 is press-fitted into the inner ring 90 a of the ball bearing 90 , and the outer ring 90 b of the ball bearing 90 is fitted and fixed to the bearing groove 73 a provided in the outer case 73 .

On the other hand, the driven pulley 83 has: an inner cylinder 96 coaxially surrounding the driven shaft 81 so as to be relatively rotatable; Close the inner cylinder 96; the fixed pulley half body 98, which is fixed in the inner cylinder 96; the movable pulley half body 99, which is opposite to the fixed pulley half body 98 and fixed on the outer cylinder 97; the torque cam mechanism 100, which is set Between the inner cylinder 96 and the outer cylinder 97, according to the relative rotational phase difference between the movable pulley half 99 and the fixed pulley half 98, an axial force acts between the two pulley halves 98, 99. Component force; coil spring 101, which elastically presses the movable pulley half body 99 toward the fixed pulley half body, and the V-shaped belt 84 rolls are hung between the fixed pulley half body 98 and the movable pulley half body 99 to form V-shaped annular groove. In addition, a centrifugal clutch 82 is provided between the inner tube 96 and the driven shaft 81 so as to be in a power transmission state when the rotation speed of the engine exceeds a set rotation speed.

Furthermore, the gap between the fixed sheave half 98 and the movable sheave half 99 of the driven pulley 83 is determined by the axial force generated by the torque cam mechanism 100 and the axial elastic force generated by the coil spring 101. 1. The balance of the force from the V-belt 84 acting on the gap between the fixed pulley half body 98 and the fixed pulley half body 99 is determined. In the drive pulley 80, if the movable pulley half body 86 When approaching the fixed pulley half body 85 to increase the wrapping radius of the V-belt 84 around the driving pulley 80 , the wrapping radius of the V-belt 84 around the driven pulley 83 becomes smaller.

The gear reduction mechanism 79 accommodated in the speed reducer chamber 76 includes: a first gear 103, which is arranged on the driven shaft 81; a second gear 104, which is arranged on an intermediate shaft 107, meshes with the first gear 103, and the intermediate shaft 107 is arranged parallel to the driven shaft 81 and the axle 77, and is rotatably supported on the inner box 72 and the reduction gear box 74; the third gear 105 is arranged on the intermediate shaft 107; the fourth gear 106 is arranged on the axle 7 on, meshes with the third gear 105.

The pedal shaft 108 is rotatably supported by the outer case 73 of the transmission case 71 , and a pedal (not shown) is provided at the outer end of the pedal shaft 108 . In addition, on the inner side of the outer case 73, a kick starter 109 is provided between the pedal shaft 108 and the crankshaft 35, which can transmit the power of the pedal shaft 108 corresponding to the pedal operation of the pedal pedal. 35 to the crankshaft.

On the outside of the fixed pulley half body 85 of the drive pulley 80, a plurality of cooling fins 110... radially arranged protrude, and the fixed pulley half body 85 also functions as a blower fan. On the other hand, the connection pipe part 111 is provided in the front part of the outer case 73, and the pipe (not shown) connected to this connection pipe part 111 extends upward from the connection pipe part 111. Then, the air in the transmission chamber 75 is discharged to the outside through the connecting pipe portion 111 and the duct according to the rotation of the fixed pulley half 85 functioning as a blower fan.

However, in the lower part of the speed reducer chamber 76 formed in the transmission case 71 and housing the gear speed reduction mechanism 79, the lubricating oil that permeates a part of the first to fourth gears 103 to 106 constituting the gear speed reduction mechanism 79 is stored. When the gas in the reducer chamber 76 thermally expands with the rise of the oil temperature, the outlet pipe part 113 that discharges the exhaust gas to the outside and communicates with the upper part of the reducer chamber 76 is provided at the end of the gear reduction case 74 of the transmission case 71. In the upper part, one end of the ventilation pipe 114 is connected to the outlet pipe part 113 . That is, one end of the breather pipe 114 is connected to the gear reduction case 74 through the upper portion in the reduction gear chamber 76 .

The vent pipe 114 extends slightly forward and upward toward the front of the vehicle frame 21 along the upper part of the transmission case 71 , and a clamping part 115 for holding the middle part of the vent pipe 114 is installed on the top of the transmission case 71 . In addition, the other end of the air duct 114 rises upward at a portion corresponding to the air filter 45 and opens upward.

In FIGS. 9 and 10, the filter box 116 of the air filter 45 consists of a front box member 117 and a rear box member 118, which are joined to each other along the width direction of the vehicle frame 21, and are joined at the front and rear. The cover part 119 on the right side of the part box parts 117 and 118 constitutes, and the element support frame 121 for holding the filter element 120 which divides the inside of the filter box 116 into a raw room and a clean room is sandwiched between the front part and the rear part. Between parts 117, 117.

In addition, an intake chamber 122 is formed between the front and rear box members 117, 118 and the cover member 119, and the front end of the intake chamber 112 opens forward as an intake port 122a. In addition, the pipe 123 that makes the rear of the intake chamber 122 communicate with the unpurified chamber is installed on the side wall of the cover member 119 side of the rear box member 118, and the upstream end of the connecting pipe 124 connected to the carburetor 47 protrudes into the purification chamber. indoor.

11 and FIG. 12 at the same time, on the cover member 119 of the filter 116, the other end of the ventilation pipe 114 is covered from the outside to be integrally provided with a ventilation outlet cover 119a, and the other end of the ventilation pipe 114 is held at the ventilation outlet. Mask 119 on.

That is, on the inner surface of the air outlet mouthpiece 119a, the holding tube 125 is extended up and down and integrally arranged. The cross-sectional shape of the holding tube 125 is rectangular and the upper end is closed. Furthermore, four protrusions 126, 126... are provided on the inner surface of the holding tube 125 and elastically contact four positions at equal intervals in the outer peripheral direction of the ventilation tube 114, and the other end of the ventilation tube 114 is inserted and held. The other end of the vent tube 114 is held elastically in the cylindrical portion 125 . In addition, in the support wall portion 128 connected to the holding cylinder portion 125, a substantially U-shaped holding groove 127 is provided near the portion where the holding cylinder portion 125 is inserted. The other end portion of the air pipe 114 held in the holding groove 127 is bent into a substantially L-shape and is inserted into and held in the holding cylinder portion 125 .

13, on the right side case half body 31R in the crankcase 31, an annular support cylinder 129 surrounding the crankshaft 35 is integrally protruded, and the outer end of the support cylinder 129 is combined with the right side case half body The right cover 131 which forms the transmission chamber 130 between 31R is connected, and the crankshaft 35 penetrates the right cover 131 liquid-tightly and rotatably.

A generator 134 having a stator 132 fixed to the right cover 131 and an outer rotor 33 fixed to a crankshaft 35 surrounding the stator 132 is disposed outside the right cover 131, and a fan 135 is fixed outside the generator 134. on the crankshaft 35. In this fan 135, a plurality of blades 135b, 135b are integrally provided on the outer peripheral portion of a root portion 135a connected to the outer rotor 133 of the engine 134 by a plurality of bolts 156. As shown in FIG.

Further referring to FIG. 14 , in the transmission chamber 130 , an oil pump 112 is installed on the right side case half body 31R, and the pump housing 136 of the oil pump 112 is composed of an end plate 137 abutting against the right side case half body 31R and the The end plate 137 is sandwiched between the right case half body 31R and constituted by a pump cover 138 connected to the right case half body 31R, and the inner rotor 139 and the outer rotor 140 are accommodated in the pump case 136 . In addition, a pump shaft 141 that is relatively non-rotatably coupled to the inner rotor 139 is rotatably supported by the pump cover 138 and the right cover 131 .

A driven gear 142 is attached to the pump shaft 141 via a pin 143 so as to be relatively non-rotatable, and a driving gear 144 meshing with the driven gear 142 is fixed to the crankshaft 35 by press fitting or the like. In addition, the drive sprocket 145 is fixed to the pump shaft 141 by pressing or the like, the endless chain 147 is wound around the driven sprocket 146 and the drive sprocket 145, and the driven sprocket 146 and the drive sprocket The sprocket 145 is mounted on the pump shaft 149 of the cooling water pump 148 via a pin 150 so as to be relatively non-rotatable.

The pump casing 151 of the cooling water pump 148 is formed by connecting the pump cover 153 to the casing main body 152 integrally formed on the right casing 131, and the impeller 154 disposed in the pump chamber 155 formed by the pump casing 151 passes through the casing body 152 The main body 152 is fixed to the pump shaft 141 which is liquid-tight and rotatably supported.

However, a cooling water jacket 158 is formed on the cylinder block 32 and the cylinder head 33 of the engine main body 30, and the discharge port 159 provided on the casing main body 152 in the pump casing 151 is connected to the cooling water provided on the cylinder block 32 via the connecting pipe 160. The inlet 158a of the water jacket 158 is connected. Furthermore, one end of the connection pipe 160 is fitted in the inlet 158a of the cooling jacket 158 in a liquid-tight manner. , the other end of the connecting pipe 160 is fitted in the discharge port 159 in a liquid-tight manner.

As shown in Fig. 13, the fan 135 fixed on the crankshaft 35 is surrounded by the fan cover 161 connected to the right half body 31R of the crankcase 31, and the radiator 162 arranged outside the fan 135 is connected by a plurality of bolts 163... Installed on the fan cover 161 , the radiator 162 is cooled by the cooling air sucked in by the fan 135 .

The radiator 162 is formed by connecting the upper case 164 and the lower case 165 arranged in parallel with the horizontal direction through the radiator core 166, has a circular louver 167 roughly corresponding to the outer end rotation track of the fan 135, and covers the radiator from the outside. The radiator cover 168 of 162 is installed on the fan cover 161 so that the louvers 167 face the radiator core 166.

In addition, an exhaust pipe cover 168 a is integrally provided under the radiator cover 168 to cover the exhaust pipe 50 extending downward from the cylinder head 33 and extending rearward through the lower part of the engine main body 30 of the power unit P from the outside. At least a part covers the upper half of the exhaust pipe 50 in this embodiment.

Due to the rotation of the fan 135, the air sucked in by the louvers 167 and the radiator core 166 forms a vortex in the fan cover 161. As shown in FIG. The air outlet 170 disposed on the intersecting plane is formed with an opening facing obliquely downward. By forming such air outlets 170 , the swirl flow in fan cover 161 is straightened without being disturbed, thereby suppressing wind noise generated when air passes through louvers 167 .

In addition, a force toward the upper side along the outer periphery of the fan cover 161 acts on the air flow discharged from the air outlet 170, but an air filter 45 is arranged above the fan cover 161, and the filter 45 has an airflow facing forward. The suction port 122a opened. Therefore, air warmed by passing through the radiator core 166 may be sucked into the air filter 45 . However, above the air outlet 170 at the upper portion of the fan case 161, the air rising from the air outlet 170 along the outer periphery of the fan case 161 is prevented from flowing toward the air filter 45 side, as shown in FIG. Two shielding walls 171 , 172 spaced apart from each other up and down protrude from the rising air flow. In FIG. 16 , in order to clearly show the shielding walls 171 and 172 , grid lines are marked on these shielding walls 171 and 172 .

Through such shielding walls 171 , 172 , the filter 45 does not inhale warm air discharged from the fan cover, and can inhale unheated fresh air.

On the side of the cylinder block 32 of the engine main body 30, a thermostat 175 for controlling the flow rate of the cooling water discharged from the cooling water jacket 158 to the radiator 162 is arranged. The pump cover 153 communicates with the inlet port 176 provided on the pump cover 153 .

Moreover, the thermostat 175 is disposed in front of the radiator 162 and approximately at the same position as the radiator core 166 of the radiator 162 along the width direction of the vehicle frame 21 . Together, it is covered by the radiator cover 168 from the outside.

As shown in FIG. 14 , in the vicinity of the intake port 46 , on the right side of the cylinder head 33 , a connecting pipe 177 communicating with the outlet 158 b of the cooling water jacket 158 is provided, and the upstream end of the cooling water hose 178 is connected to the connecting pipe 177 . connect. In addition, the downstream end of the cooling water hose 178 is connected to a T-shaped joint 179 , and the cooling water hose 180 , whose upstream end is connected to the joint 179 , is connected to the upper tank 164 of the radiator 162 . Moreover, the joint 179 and the thermostat 175 are connected by a bypass cooling water hose 181 that introduces cooling water from the cooling water jacket 158 to the thermostat 175 side, and between the lower tank 165 of the radiator 162 and the thermostat 175 They are connected by cooling water hose 182.

Next, the action of this embodiment will be described. One end of the driven shaft 81 , which is a component of the transmission T constituting the power unit P together with the engine E, is rotatably supported via a cylindrical bush 93 and a ball bearing 90 . On the outer case 73 facing the transmission chamber 75 which is a dry space, the bush 93 is made of porous sintered alloy and impregnated with engine oil, is mounted on the driven shaft 81 , and is pressed into the ball bearing 90 . Circle 90a.

Therefore, there is no need to perform complex processing on the bush 93 for lubrication, and the lubricity of the one-end support portion of the driven shaft 81 is improved, and a long-life and low-cost support structure can be realized without using special bearing materials or lubricating oil. . Furthermore, by installing the bush 93 between the ball bearing 90 and the driven shaft 81, compared with fitting the driven shaft 81 directly on the ball bearing 90, the wear of the driven shaft 81 due to friction can be reduced. , since the bushing 93 can be simply replaced when it wears out, costs can be reduced in this respect.

In addition, the outer ring 90b of the ball bearing 90 is fitted and fixed on the bearing groove 73a of the outer case 73. By installing the bush 93 between the driven shaft 81 and the ball bearing 90, the outer ring 90b of the ball bearing 90 can be made The diameter becomes relatively large, which can reduce the surface pressure on the outer case that fits and fixes the ball bearing 90 .

However, the transmission T constituting the power unit P together with the engine E is composed of a continuously variable transmission 78 for changing the output of the engine E, and a gear reduction mechanism 79 for decelerating the output of the continuously variable transmission 78 and transmitting it to the rear wheels WR. A transmission chamber 75 accommodating a continuously variable transmission 78 and a speed reducer chamber accommodating a gear reduction mechanism 79 and storing oil in the lower part are formed in a transmission case 71 connected to the engine main body 30 and extending laterally to the rear wheel WR. 76, in order to communicate with the upper part in the reducer chamber 76, the vent pipe 114 that one end is connected to the outlet pipe part 113 provided on the top of the reduction gear 74 of the transmission case 171 extends forward along the top of the transmission case 71, and the vent pipe The other end of 114 opens upward.

Therefore, can reliably prevent that the muddy water splashed along with the scooter-type vehicle from invading in the vent pipe 114, and, by the vent pipe 114 extending forward along the transmission case 71, the passage in the vent pipe 114 becomes longer, can promote The gravitational separation of the engine oil prevents the oil from adhering and accumulating at the opening at the other end of the vent pipe 114 .

In addition, an air filter 45 is disposed above the power unit P, and the other end of the air pipe 114 is covered and held on the air outlet cover 119a from the outside by the air outlet cover 119a provided on the filter box 116 of the filter 45. Therefore, a dedicated part for holding the other end of the vent pipe 114 is not required, the number of parts can be reduced, and the appearance can be improved by covering the other end of the vent pipe 114 from the outside.

In addition, an exhaust port 49 is provided on the lower side of the cylinder head 33 of the engine E, and an exhaust pipe 50 connected to the exhaust port 49 at the upstream end extends downward from the cylinder head 33 and passes through the lower part of the engine body 30 to the rear. A hose 61 that is extended and introduced to purify waste secondary air is connected to the exhaust port 49 through a metal connection pipe 62, and a U-shaped portion 62 that is bent into a U-shape is formed on a part of the connection pipe 62. The U-shaped portion 62 a is arranged between the lower side surface of the cylinder head 33 and the exhaust pipe 50 as viewed from the side.

Therefore, by forming the U-shaped portion 62a, the length of the connecting pipe 62 can be adjusted, and the space between the lower side of the cylinder head 33 and the exhaust pipe 50 can be effectively utilized to arrange the extended connecting pipe 62 . Moreover, the U-shaped portion 62a is disposed below the cylinder head 33. As in this embodiment, even if the air filter 45 is disposed above the power unit P, the cylinder head 33 can block the heat from the U-shaped portion 62a from affecting the air filtration. 45 side, just can prevent air filter 45 from sucking the air of heating.

In addition, since a part of the U-shaped portion 62a is disposed between the cylinder head 33 and the exhaust pipe 50, the U-shaped portion 62a of the connecting pipe 62 is set to a sufficient length to sufficiently reduce the temperature at the upstream end of the connecting pipe 62, and pass The heat from the exhaust pipe 50 heats a part of the U-shaped portion 62a, and the heated secondary air is supplied to the exhaust port 49, thereby improving exhaust gas purification performance.

In addition, a radiator 162 and a thermostat 175 for controlling the flow rate of the cooling water discharged from the cooling water jacket 158 to the radiator 162 are disposed on the right side of the engine body 30 having the cooling water jacket 158. The radiator core 165 of the frame 21 is arranged at substantially the same position as the radiator core 165 of the radiator 162, and the thermostat 175 is covered from the outside by the common radiator cover 168. On the one hand, the number of parts and the man-hours for installation can be reduced.

In addition, the exhaust pipe 50 connected to the cylinder head 33 extends rearward through the lower part of the engine body 30, and since the radiator cover 168 is integrally provided with an exhaust pipe cover 168a covering at least a part of the exhaust pipe 50 from the outside, Therefore, in addition to the radiator 162 and the thermostat 175, the radiator cover 168 also covers at least a part of the exhaust pipe 50 below the engine main body 30 from the outside, so that the number of parts can be reduced.

In addition, the cooling water pump 148 is installed on the engine main body 30, and the thermostat 175 is installed on the pump cover 153 of the pump case 151 of the cooling water pump 148, so that the approximate distance between the radiator core 166 and the radiator core 166 along the width direction of the vehicle frame 21 can be effectively utilized. By disposing the cooling water pump 148 in the space between the thermostat 175 and the engine main body 30 at the same position, the layout around the engine E can be downsized.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various design changes are possible without departing from the scope of the technical solutions of the present invention.

Claims (3)

1. autobicycle, at side configuration radiator (162) and calorstat (175) with cooling-water chamber (158) and lift-launch engine main body (30) on vehicle frame (21), this calorstat (175) control is from the flow of described cooling-water chamber (158) row to the cooling water expansion tank of described radiator (162), it is characterized in that, described radiator (162) and be configured in the roughly described calorstat (175) of same position along the radiator cell (166) that the Width and the described radiator (162) of described vehicle frame (21) had is capped from the outside by common radiator shell (168).

2. autobicycle as claimed in claim 1, it is characterized in that, rearward extend by the below of engine main body (30) with cylinder head (33) the bonded assembly freeing pipe (50) of described engine main body (30), be arranged on integratedly on the described radiator shell (168) from the exhaust pipe shield portion (168a) of at least a portion of the described freeing pipe of outer side covers (50).

3. autobicycle as claimed in claim 1 or 2 is characterized in that, goes up the pump case (151) of the cooling water pump of installing (148) at described engine main body (30) and goes up installation described calorstat (175).

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